Autophony of eyelid movement is not independent of eyeball movement

https://ift.tt/2Lmhxyl

Improvement in minimal cross-sectional area and nasal-cavity volume occurs in different areas after septoplasty and radiofrequency therapy of inferior turbinates

Abstract

Purpose

Septoplasty and radiofrequency therapy for inferior turbinate hypertrophy (RFIT) are common techniques used to improve nasal patency. Our aim was to compare nasal geometry and function using acoustic rhinometry and peak nasal inspiratory flow (PNIF) in three patients groups undergoing surgery for nasal obstruction, and to investigate if the improvement in minimal cross-sectional area (MCA) and nasal-cavity volume (NCV) occurred in different cavity areas in the groups. Finally, we evaluated the correlation between the objective measurements and the patients' assessment of nasal obstruction (SNO).

Methods

This prospective, observational study investigated 148 patients pre-operatively and 6 months post-operatively. Fifty patients underwent septoplasty (group 1), 51 underwent septoplasty combined with RFIT (group 2), and 47 underwent RFIT alone (group 3). The MCA and NCV were measured at two distances (MCA/NCV_0–3.0 and MCA/NCV_3–5.2), in addition to measuring PNIF and SNO.

Results

Pre-operatively, groups 1 and 2 had narrower MCA_0–3.0 on one side than group 3 (0.31 ± 0.14 and 0.31 ± 0.14) versus (0.40 ± 0.16) cm². Post-operatively, total MCA_0–3.0 and MCA/NCV_3–5.2 increased in group 1. In group 2, MCA/NCV_0–3.0 at the narrow side and total MCA/NCV_3–5.2 increased, while total MCA/NCV_3–5.2 increased in group 3. PNIF improved from 106 ± 49 to 150 ± 57 l/min post-operatively. We found a correlation between increased MCA and NCV and less SNO in the septoplasty group (p < 0.01).

Conclusion

Surgery produced an improvement in MCA and NCV in all groups. The improvement occurred in different areas of the nasal cavity in the patient groups. Both anterior and posterior areas increased in the septoplasty groups, while only the posterior area increased in the RFIT group. PNIF improved in all three patient groups, indicating that surgery produced an improvement in nasal patency.

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Oncological and functional outcomes of transoral laser surgery for laryngeal carcinoma

Abstract

Introduction

Transoral laser microsurgery (TLM) has become the standard approach for treatment of early-stage laryngeal carcinoma in most institutions due to their good oncological and functional results with few local complications. The purpose of this study was to analyze the oncological and functional results of TLM in the treatment of laryngeal tumors at our Hospital.

Materials and methods

Patients with laryngeal squamous cell carcinoma (LSCC) treated from 1998 to 2013 with TLM with curative intention, and with a minimum follow-up of 24 months, were reviewed.

Results

203 patients with LSCC were included. 195 patients were men (96%) and 8 women (4%), with a mean age of 63 years. The series includes 134 (66%) T1, 40 (20%) T2, and 29 (14%) T3-classified tumors. 116 tumors (57%) were in the glottis, 79 (39%) in the supraglottis and 8 (4%) in the anterior commissure. 16 patients (8%) received adjuvant radiotherapy. Initial local control was obtained in 75.5% of patients. The 5-year overall survival rate was 84% and the 5-year disease-specific survival was 90%. The presence of nodal metastasis (p < 0.001) and the involvement of the surgical margins (p = 0.004) were associated with a lower disease-specific survival in the multivariate analysis. All but three patients with local control of the disease reassumed oral diet, and none were tracheostomy-dependent. The 5-year laryngeal preservation rate was 85%.

Conclusions

TLM is a minimally invasive treatment for early and moderately-advanced laryngeal carcinomas, with good oncologic and functional outcomes, and few complications as well.

https://ift.tt/2LntPXg

The influence of TAP1 and TAP2 gene polymorphisms on TAP function and its inhibition by viral immune evasion proteins

Publication date: September 2018
Source:Molecular Immunology, Volume 101
Author(s): P. Praest, R.D. Luteijn, I.G.J. Brak-Boer, J. Lanfermeijer, H. Hoelen, L. Ijgosse, A.I. Costa, R.D. Gorham, R.J. Lebbink, E.J.H.J. Wiertz
Herpesviruses encode numerous immune evasion molecules that interfere with the immune system, particularly with certain stages in the MHC class I antigen presentation pathway. In this pathway, the transporter associated with antigen processing (TAP) is a frequent target of viral immune evasion strategies. This ER-resident transporter is composed of the proteins TAP1 and TAP2, and plays a crucial role in the loading of viral peptides onto MHC class I molecules. Several variants of TAP1 and TAP2 occur in the human population, some of which are linked to autoimmune disorders and susceptibility to infections. Here, we assessed the influence of naturally occurring TAP variants on peptide transport and MHC class I expression. In addition, we tested the inhibitory capacity of three viral immune evasion proteins, the TAP inhibitors US6 from human cytomegalovirus, ICP47 from herpes simplex virus type 1 and BNLF2a from Epstein-Barr virus, for a series of TAP1 and TAP2 variants. Our results suggest that these TAP polymorphisms have no or limited effect on peptide transport or MHC class I expression. Furthermore, our study indicates that the herpesvirus-encoded TAP inhibitors target a broad spectrum of TAP variants; inhibition of TAP is not affected by the naturally occurring polymorphisms of TAP tested in this study. Our findings suggest that the long-term coevolution of herpesviruses and their host did not result in selection of inhibitor-resistant TAP variants in the human population.



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Deleterious single nucleotide polymorphisms of protein kinase R identified by the computational approach

Publication date: September 2018
Source:Molecular Immunology, Volume 101
Author(s): Anna Maria Melzer, Navaneethan Palanisamy
The human protein kinase R (PKR) recognizes invading RNA viruses and mediates the antiviral immune response by phosphorylating the eukaryotic translation initiation factor 2α (eIF-2α), thus blocking protein translation in infected cells and thus preventing viral replication. The observation that individuals show different degrees of susceptibility to viral infections gives rise to the hypothesis that single nucleotide polymorphisms (SNPs) in the protein kinase R may alter the response to an infection. Using different available servers (e.g. SIFT, PROVEAN, Polyphen2, SNAP2, SNP&GOs, SNP-PhD, I-Mutant Suite), 14 SNPs were identified that were predicted to have deleterious effects on the protein kinase R. Five SNPs, namely D266Y, Y323D, I398 K, Y465C and Y472C, were selected for homology modeling and the generated models were investigated with regard to their secondary structure, residue fluctuations and eIF-2α binding. Analysis with computational tools POLYVIEW-MM, SAAPdap, SRIDE, CMView, elNémo, NMsim and PatchDock revealed structural changes in all mutants yielding a more stable structure at the cost of reduced flexibility (except Y465C) and less conformational freedom compared to the native protein. The conformational changes in the mutant protein structures and the displacement of functional residues from their strategic positions are predicted to affect the functionality of PKR, and consequently will affect the efficiency of the individual's antiviral immune response negatively. This study will aid the physicians in precision medicine field to tailor optimal treatment for the patients.



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Microbiota and Type 2 immune responses

Kathy D McCoy | Aline Ignacio | Markus B Geuking

https://ift.tt/2JjRyap

All along the watchtower: group 2 innate lymphoid cells in allergic responses

Madelene W Dahlgren | Ari B Molofsky

https://ift.tt/2Jgccbf

Why do proteases mess up with antigen presentation by re-shuffling antigen sequences?

Juliane Liepe | Huib Ovaa | Michele Mishto

https://ift.tt/2Hmvvhl

In vivo Efficacy of Relebactam (MK-7655) in Combination with Imipenem/Cilastatin in Murine Infection Models [PublishAheadOfPrint]

The World Health Organization has identified antimicrobial resistance as a global public health threat as the prevalence and spread of antibiotic resistance among bacterial pathogens worldwide are staggering. Carbapenems, such as imipenem and meropenem have been used to treat multidrug-resistant bacteria; however, since the development of resistance to carbapenems, β-lactam antibiotics in combination with β-lactamase inhibitors (BLI) has been one of the most successful strategies to enhance the activity of β-lactam antibiotics. Relebactam (REL) is a new BLI which has been found to inhibit Class A and Class C β-lactamases in vitro. REL has been reported to restore imipenem's activity against both imipenem-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae. Reported here are the in vivo efficacy studies of the imipenem-cilastatin (IMI)/REL combination in mouse models of disseminated and pulmonary infection caused by imipenem-resistant clinical isolates of P. aeruginosa and K. pneumoniae. The combination was also evaluated in a P. aeruginosa delayed pulmonary model of infection. IMI/REL was found to be effective in the disseminated model of infection with log reduction in P. aeruginosa CFUs of 3.73, 3.13, and 1.72 at REL doses of 40, 20, and 10 mg/kg, respectively. For K. pneumoniae, log reductions in CFU of 2.36, 3.06, and 2.29 were reported at REL doses of 80, 40, and 20 mg/kg, respectively. The combination was less effective in the delayed pulmonary model than in the immediate pulmonary model; however, overall REL was found to be effective against these imipenem-resistant strains.

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Pentamidine for Prophylaxis against Pneumocystis jirovecii Pneumonia in Pediatric Oncology Patients Receiving Immunosuppressive Chemotherapy [PublishAheadOfPrint]

Background: Pneumocystis jirovecii pneumonia is a life-threatening opportunistic infection in children receiving immunosuppressive chemotherapy. Without prophylaxis, up to 25% of pediatric oncology patients receiving chemotherapy will develop Pneumocystis jirovecii pneumonia. Trimethoprim-sulfamethoxazole is the preferred agent for prophylaxis against Pneumocystis jirovecii pneumonia. Pentamidine may be an acceptable alternative for pediatric patients unable to tolerate trimethoprim-sulfamethoxazole.

Methods: A retrospective review was conducted of pediatric oncology patients who received ≥ 1 dose of pentamidine for Pneumocystis jirovecii pneumonia prophylaxis between January 2007 and August 2014. Electronic medical records were reviewed to determine incidence of breakthrough Pneumocystis jirovecii pneumonia or discontinuation of pentamidine associated with adverse events.

Results: A total of 754 patients received pentamidine prophylaxis during the period. There were no cases of probable or proven Pneumocystis pneumonia, and 4 cases (0.5%) of possible Pneumocystis pneumonia. The incidence of possible breakthrough Pneumocystis pneumonia was not significantly different between subgroups based on age (< 12 months [1.7%] vs. ≥ 12 months [0.4%], p=0.3), route of administration (aerosolized [0%] vs. intravenous [1.0%], p=0.2), or hematopoietic stem cell transplant status (transplant [0.4%] vs. no transplant [0.8%], p=0.6). Pentamidine was discontinued due to an adverse drug event in 23 children (3.1%); more frequently for aerosolized than intravenous administration (7.6% vs. 2.2%, P=0.004).

Conclusions: Intravenous or inhaled pentamidine may be a safe and effective second-line alternative for prophylaxis against Pneumocystis jirovecii pneumonia in children with cancer receiving immunosuppressive chemotherapy or hematopoietic stem cell transplantation.

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Pharmacodynamic and immunomodulatory effects of micafungin on host responses against biofilms of Candida parapsilosis in comparison to those of Candida albicans [PublishAheadOfPrint]

Micafungin (MFG) demonstrates potent activity against biofilms of Candida albicans and Candida parapsilosis, the most frequent opportunistic fungal pathogens. Little is known about its immunopharmacological effect on antibiofilm activity of phagocytic cells following exposure to Candida biofilms. In this study, we investigated the effects of MFG on human neutrophil-mediated damage of C. albicans and C. parapsilosis biofilms by XTT and the potential mechanisms underlying the immunomodulatory MFG activities on cultured monocyte-derived THP-1 cells in response to these biofilms by RT-PCR, sandwich and multiplex ELISA. Pre-exposure of C. albicans to subinhibitory MFG concentrations significantly enhanced neutrophil-mediated biofilm damage, an effect that appears to be species-specific as a comparable effect was not observed with drug-pretreated C. parapsilosis biofilms. Human THP-1 cells responded to both Candida biofilms through TLR2 and TLR4 up-regulation, modest TLR6 involvement and enhanced NLRP3 activation, whereas the signal was relayed to the nucleus via NF-B p65 activation. MFG caused 2- to 3-fold lower TLR2 and TLR4 mRNA levels compared to those caused by either organism. C. albicans biofilms induced a robust proinflammatory response, whereas C. parapsilosis biofilms either alone or in the presence of MFG caused increased IL-1β production, but low amounts of IL-8, IL-23 and TNF-α. In conclusion, MFG may condition THP-1 cells towards an inflammatory response through TLR2/TLR4 recruitment. Inflammatory signals observed with C. albicans biofilms, are considerably reduced upon exposure of THP-1 cells to C. parapsilosis biofilms possibly enhancing fungal survival and increasing biofilm pathogenicity.

https://ift.tt/2kQwU78

Non-proteinogenic Amino Acid Containing Nucleotide Prodrug to Improve Oral Delivery of a Hepatitis C Virus Treatment [PublishAheadOfPrint]

Delivery of pharmacologically active nucleoside triphosphate analogs to sites of viral infection is challenging. In prior work we identified a 2'-C-methyl-1'-cyano-7-deaza-adenosine C-nucleotide analog with desirable selectivity and potency for the treatment of HCV infection. However, the prodrug selected for clinical development, GS-6620, required a high dose for meaningful efficacy and had unacceptable variability due to poor oral absorption as a result of suboptimal solubility, intestinal metabolism and efflux transport. While obtaining clinical proof of concept for the nucleotide analog, a more effective prodrug strategy would be necessary for clinical utility. Here we report an alternate prodrug of the same nucleoside analog identified to address liabilities of GS-6620. A phosphoramidate prodrug containing the non-proteinogenic amino acid methylalanine, an isopropyl ester and phenol in the (S) conformation at phosphorous, GS2, was found to have improved solubility, intestinal stability and hepatic activation. GS2 is a more selective substrate for hepatically expressed carboxyl esterase (CES) 1 and is resistant to hydrolysis by more widely expressed hydrolases including cathepsin A (CatA) and CES2. Unlike GS-6620, GS2 was not cleaved by intestinally expressed CES2 and as a result, was stable in intestinal extracts. Levels of liver triphosphate following oral administration of GS2 in animals were higher than GS-6620 even when administered under optimal conditions for GS-6620 absorption. Combined these properties suggest that GS2 will have better oral absorption in the clinic when administered in a solid dosage form and the potential to extend the clinical proof of concept obtained with GS-6620.

https://ift.tt/2Hle6FT

Artemisone and artemiside - potent pan-reactive antimalarial agents that also synergize redox imbalance in P. falciparum transmissible gametocyte stages [PublishAheadOfPrint]

The emergence of resistance towards artemisinin combination therapies (ACTs) by the malaria parasite Plasmodium falciparum has the potential to severely compromise malaria control. Therefore, development of new artemisinins in combination with new drugs that impart activities towards both intraerythrocytic proliferative asexual and transmissible gametocyte stages, in particular those of resistant parasites, are urgently required. We define artemisinins as oxidant drugs through their ability to oxidize reduced flavin cofactors of flavin disulfide reductases critical for maintaining redox-homeostasis in the malaria parasite. Here we compare the activities of 10-amino artemisinin derivatives towards the asexual and gametocyte stages of P. falciparum parasites. Of these, artemisone and artemiside inhibited asexual and gametocyte stages, particularly stage V gametocytes in the low nM range. Further, treatment of both early and late gametocyte stages with artemisone or artemiside combined with the pro-oxidant redox partner methylene blue displays notable synergism. These data suggest that modulation of redox-homeostasis likely is an important druggable process, particularly in gametocytes, and thereby enhances the prospect of using combinations of oxidant and redox drugs for malaria control.

https://ift.tt/2JadQiW

In Vitro and In Vivo activity of a novel catheter lock solution against bacterial and fungal biofilms [PublishAheadOfPrint]

Central line associated bloodstream infections (CLABSIs) are increasingly recognized to be associated with intralumenal microbial biofilms, and effective measures for the prevention and treatment of BSI remain lacking. This report evaluates a new commercially developed antimicrobial catheter lock solution (ACL) containing trimethoprim (5 mg/ml) and ethanol (25%) and calcium Ethylenediaminetetraacetic acid (CA-EDTA) 3% for activity against bacterial and fungal biofilms using in vitro and in vivo (rabbit) catheter biofilm models. Biofilms were formed with bacterial (seven different species including vancomycin-resistant enterococcus, VRE) or fungal (C. albicans) species on catheter materials. Biofilm formation was evaluated by quantitative culture (colony forming units, CFUs) and scanning electron microscopy (SEM). Treatment with ACL inhibited growth of adhesion phase biofilms in vitro after 60 min (VRE) or 15 min (all others), while mature biofilms were completely inhibited after exposure for 2 or 4 h, compared to control. Similar results were observed for drug-resistant bacteria. In the catheterized rabbit model, when compared against heparinized saline control, ACL lock therapy significantly reduced the catheter bacterial (3.49 ± 0.75 vs. 0.03 ± 0.06 log CFU/catheter, respectively; P = 0.016) and fungal burden (2.48 ± 1.60 vs. 0.55 ± 1.19 log CFU/catheter segment, respectively; P = 0.013). SEM also demonstrated eradication of bacterial and fungal biofilms in vivo on catheters exposed to ACL, while vigorous biofilms were observed on untreated control catheters. Our results demonstrate that ACL was efficacious against both adhesion phase and mature biofilms formed by bacteria and fungi in vitro as well as in vivo.

https://ift.tt/2HnIgbK

In Vivo Efficacy of Plazomicin Alone or in Combination with Meropenem or Tigecycline against Enterobacteriaceae Isolates Exhibiting Various Resistance Mechanisms in an Immunocompetent Murine Septicemia Model [PublishAheadOfPrint]

Background: Plazomicin is a next-generation aminoglycoside with potent in vitro activity against multidrug- and carbapenem-resistant Enterobacteriaceae. The objective of this study was to assess the efficacy of plazomicin exposure, alone and in combination with meropenem or tigecycline, against Enterobacteriaceae in the immunocompetent murine septicemia model.

Methods: ICR mice were inoculated intraperitoneally with bacterial suspensions. Eight Enterobacteriaceae isolates with wide ranges of plazomicin, meropenem and tigecycline MICs were utilized. Treatment mice were administered plazomicin, meropenem or tigecycline human-equivalent doses alone or in combinations of plazomicin/meropenem and plazomicin/tigecycline. Treatments were initiated 1h post-infection and continued for 24h. Efficacy was assessed by survival through 96h.

Results: Compared with controls, plazomicin monotherapy produced significant improvement in survival for all isolates (P<0.05) and resulted in overall survival of 86% (n=50) and 53.3% (n=30) for isolates with plazomicin MIC ≤4 and ≥8 mg/L, respectively (P<0.05). Survival of meropenem and tigecycline groups correlated well with their respective susceptibilities, with incremental increase in survival observed at lower MIC values. For isolate KP 561 (plazomicin, meropenem and tigecycline MICs of 8, >32 and 2 mg/L, respectively), combination therapies showed significant reduction in mortality compared with any monotherapy (P<0.05).

Conclusion: Plazomicin monotherapy resulted in improved survival in the immunocompetent murine septicemia model, notably for isolates with plazomicin MIC ≤4 mg/L. As evidenced by our current data, co-administration of meropenem or tigecycline could potentially lead to further improvement in survival. These data support a role for plazomicin in the management of septicemia due to Enterobacteriaceae with plazomicin MIC ≤4 mg/L, including carbapenem-resistant isolates.

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In vitro and intracellular activity of imipenem combined to rifabutin and avibactam against Mycobacterium abscessus [PublishAheadOfPrint]

Repurposing drugs may be useful as an add-on in the treatment of Mycobacterium abscessus pulmonary infections, which are particularly difficult to cure. M. abscessus naturally produces a β-lactamase, Bla_Mab, which is inhibited by avibactam. The recommended regimens include imipenem, which is hydrolyzed by Bla_Mab and used without any β-lactamase inhibitor. Here, we determine whether the addition of rifabutin improves the activity of imipenem alone or in combination with avibactam against M. abscessus CIP104536. Rifabutin at 16 μg/ml was only bacteriostatic (MIC = 4 μg/ml) and was moderately synergistic in combination with imipenem (FIC index of 0.38). Addition of rifabutin (16 μg/ml) moderately increased killing by a low (8 μg/ml) but not by a high (32 μg/ml) concentration of imipenem. Addition of avibactam (4 μg/ml) did not further increase killing by the former combination. In infected macrophages, rifabutin (16 μg/ml) increased the activity of imipenem at 8 and 32 μg/ml achieving 3- and 100-fold reductions in the number of intracellular bacteria, respectively. Avibactam (16 μg/ml) improved killing by imipenem at 8 μg/ml. A 5-fold killing was obtained for a triple combination comprising avibactam (16 μg/ml) and therapeutically-achievable doses of imipenem (8 μg/ml) and rifabutin (1 μg/ml). These results indicate that the imipenem-rifabutin combination should be further considered for the treatment of M. abscessus pulmonary infections in cystic fibrosis patients and that addition of a β-lactamase inhibitor might improve its efficacy. Mechanistically, the impact of Bla_Mab inhibition by avibactam on antibiotic activity was assessed by comparing CIP104536 and a β-lactamase-deficient derivative.

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Effect of Linezolid plus Bedaquiline against Mycobacterium tuberculosis in Log-Phase, Acid-Phase and Non-Replicating-Persister (NRP)-Phase in an In vitro Assay [PublishAheadOfPrint]

Tuberculosis is the ninth-leading cause of death worldwide. Treatment success is approximately 80% for susceptible strains and decreases to 30% for extensively resistant strains. Shortening therapy duration for Mycobacterium tuberculosis (Mtb) is a major goal, which can be attained with the use of combination therapy. However, the identification of the most promising combination is a challenge given the quantity of older and newer agents available. Our objective was to identify promising 2-drug combinations using an in vitro strategy to ultimately be tested in an in vitro Hollow Fiber Infection Model (HFIM) and in animal models. We studied the effect of the combination of linezolid (LZD) and bedaquiline (BDQ) on Mtb strain H37Rv in Log- and Acid-Phase growth and Mtb strain 18b in Log- and Non-Replicating-Persister-Phase growth in a plate system containing a 9 x 8 matrix of concentrations of both drugs alone and in combinations. Characterization of the interaction as antagonistic, additive, or synergistic was performed using the Greco Universal Response Surface Approach (URSA) model. Our results indicate that the interaction between LZD and BDQ is additive for bacterial killing in both strains for both of the metabolic states tested. This prescreen strategy was suitable to identify LZD and BDQ as a promising combination to be further tested in the HFIM. The presence of non-overlapping mechanisms of drug action suggests each drug in the combination will likely be effective in suppressing emergence of resistance by Mtb to the companion drug, which holds promise in improving treatment outcomes for tuberculosis.

https://ift.tt/2kMhYqs

Efficacy of Meglumine Antimoniate under Low Polymerization State Orally Administrated in Murine Model of Visceral Leishmaniasis [PublishAheadOfPrint]

Progress towards the improvement of meglumine antimoniate (MA) commercially known as Glucantime®, a highly effective but also toxic antileishmanial drug, has been hindered by the lack of knowledge and control on its chemical composition. Here, MA was manipulated chemically with the aim of achieving an orally effective drug. MA compounds were synthesized from either antimony pentachloride (MA-SbCl₅) or potassium hexahydroxyantimonate (MA-KSb(OH)₆) and prepared under low polymerization state. Those were compared to Glucantime® regarding chemical composition, permeation properties across cellulose membrane and Caco-2 cell monolayer and uptake by peritoneal macrophages. MA-SbCl₅ and MA-KSb(OH)₆ were characterized as less polymerized and more permeable 2:2 Sb-meglumine complexes, when compared to Glucantime® that consisted in a mixture of 2:3 and 3:3 Sb-meglumine complexes. The antileishmanial activity and hepatic uptake of all compounds were evaluated after oral administration in BALB/c mice infected with Leishmania infantum chagasi, as model of visceral leishmaniasis (VL). The synthetic MA compounds given at 300 mg Sb/kg/12h for 30 days reduced significantly spleen and liver parasite burdens, in contrast to Glucantime® at the same dose. The greater activity of synthetic compounds could be attributed to their higher intestinal absorption and accumulation efficiency in the liver. MA-SbCl₅ given orally was as efficacious as Glucantime® by parenteral route (80 mg Sb/kg/24h IP). This data taken altogether suggests that treatment with less polymerized form of MA by oral route may be effective for the treatment of VL.

https://ift.tt/2sE7i0T

Diversity of carbapenemase-producing Escherichia coli isolates, France 2012-2013 [PublishAheadOfPrint]

With the dissemination of carbapenemase-producing Enterobacteriaceae (CPE) worldwide, carbapenem-hydrolyzing enzymes are increasingly reported among Escherichia coli, the first hospital and community-acquired opportunistic pathogen. Here, we have performed an epidemiological survey of carbapenemase-producing E. coli (CP-Ec) isolates received at the French National Reference Centre (F-NRC) in 2012 and 2013. Antimicrobial susceptibilities for last resort antibiotics and antimicrobial compounds commonly used to treat urinary tract infections were determined by broth microdilution. Clonal relationship was assessed using rep-PCR and MLST typing. From this collection of 140 carbapenemase-producing E. coli, (74%) produced an OXA-48-like carbapenemase followed by NDM (21%). A link with a foreign country was suspected for 37% of infected/colonized patients. Most of the isolates were from screening (56%) and from urine samples (26%). Colistin, fosfomycin and nitrofurantoin possessed the most consistent activity with 100%, 95% and 96% of susceptibility, respectively. A wide diversity of carbapenemase-producing E. coli isolates has been found (50 different STs). The most prevalent clones were (i) E. coli ST38 producing-OXA-48 (n=21), a clone related to Turkey and North African countries, (ii) E. coli ST-90 producing OXA-204 (n=9), which was responsible of an outbreak related to a contaminated duodenoscope, and (iii) E. coli ST-410 producing OXA-181 (n=5) recovered from patients of different geographical origin. These specific clones might be considered high-risk clones for the dissemination of carbapenemases in E. coli. The wide diversity of STs combined with the increasing number of CP-Ec isolates received by the F-NRC suggests a likely dissemination of CP-Ec isolates in the community.

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Evaluation of the Bactericidal Activity of Plazomicin and Comparators against Multidrug-resistant Enterobacteriaceae [PublishAheadOfPrint]

The next-generation aminoglycoside plazomicin, in development for infections due to multi-drug resistant (MDR) Enterobacteriaceae, was evaluated alongside comparators for bactericidal activity in minimum bactericidal concentration (MBC) and time-kill (TK) assays against MDR Enterobacteriaceae isolates with characterized aminoglycoside and β-lactam resistance mechanisms. Overall, plazomicin and colistin were the most potent, with plazomicin demonstrating an MBC_50/90 of 0.5/4 μg/mL and sustained 3-log₁₀ kill against MDR Escherichia coli, Klebsiella pneumoniae and Enterobacter spp.

https://ift.tt/2Hjj1qQ

Few conserved amino acids in the small multidrug resistance transporter EmrE influence drug polyselectivity. [PublishAheadOfPrint]

EmrE is the archetypical member of the small multidrug resistance transporter family and confers resistance to a wide range of disinfectants and dyes known as quaternary cation compounds (QCCs). The aim of this study was to examine which conserved amino acids play an important role in substrate selectivity. Based on previous analysis of EmrE homologs, a total of 33 conserved residues were targeted for cysteine or alanine replacements within E. coli EmrE. The antimicrobial resistance of each EmrE variant expressed in E. coli strain JW0451 (lacking dominant pump acrB) was tested against a collection of 16 different QCCs using agar spot dilution plating to determine MIC values. The results determined that few conserved residues were drug polyselective: the active site residue E14 (E14D and E14A) and 4 additional conserved residues (A10C, F44C, L47C, W63A) based on ≥4 fold decreases in MIC values. EmrE variants (I11C, V15C, P32C, I62C, L93C, S105C) enhanced resistance to polyaromatic QCCs, while the remaining EmrE variants reduced resistance to one or more QCCs with shared chemical features: acylation, tri-and tetra-phenylation, aromaticity, and dicationic charge. Mapping EmrE variants onto transmembrane helical wheel projections using the highest resolved EmrE structure suggests that polyselective EmrE variants were located closest to helical faces surrounding the predicted drug binding pocket, while EmrE variants with greater drug specificity mapped onto distal helical faces. This study reveals that few conserved residues are essential for drug polyselectivity and indicates that aromatic QCC selection involves a greater portion of conserved residues compared to other QCCs.

Importance EmrE is an archetypical member of the small multidrug resistance efflux pump family and its members are frequently identified from mobile genetic elements and multidrug resistant plasmids. This study examines conserved residues in EmrE and their MIC to various quaternary ammonium compounds which may shed light on the importance of conserved residues in other EmrE orthologues. In this study, few conserved EmrE residue replacements are required for drug polyselectivity but indicate that many conserved residues that may be important for polyaromatic QCC selection which may be useful for future efflux pump inhibition and inactivation studies.

https://ift.tt/2kRCplP

In Vitro Activity of Plazomicin against Gram-Negative and Gram-Positive Isolates Collected from United States Hospitals and Comparative Activity of Aminoglycosides against Carbapenem-Resistant Enterobacteriaceae and Isolates Carrying Carbapenemase Genes [PublishAheadOfPrint]

Plazomicin and comparators agents were tested using the CLSI reference broth microdilution method against 4,825 clinical isolates collected during 2014 and 2015 in 70 United States hospitals as part of the ALERT (Antimicrobial Longitudinal Evaluation and Resistance Trends) program. Plazomicin (MIC_50/90, 0.5/2 μg/ml) inhibited 99.2% of 4,362 Enterobacteriaceae at ≤4 μg/ml. Amikacin, gentamicin, and tobramycin inhibited 98.9%, 90.3%, and 90.3% of these isolates, respectively, applying CLSI breakpoints. The activity of plazomicin was similar among Enterobacteriaceae species with MIC₅₀ values ranging from 0.25 to 1 μg/ml, with exception of Proteus mirabilis and indole-positive Proteaee that displayed MIC₅₀ values of 2 μg/ml. Against 97 carbapenem-resistant Enterobacteriaceae (CRE) that included 87 isolates carrying bla_KPC, plazomicin inhibited all but 1 isolate at ≤2 μg/ml (99.0% and 98.9%, respectively). Amikacin and gentamicin inhibited 64.9% and 56.7% of the CRE isolates at the respective CLSI breakpoints. Plazomicin inhibited 96.5/95.5% of the gentamicin-resistant, 96.9/96.5% of the tobramycin-resistant and 64.3/90.0% of the amikacin-resistant isolates using CLSI/EUCAST breakpoints. The activity of plazomicin against Pseudomonas aeruginosa (MIC_50/90, 4/16 μg/ml) and Acinetobacter spp. (MIC_50/90, 2/16 μg/ml) isolates was similar. Plazomicin was active against coagulase-negative staphylococci (MIC_50/90, 0.12/0.5 μg/ml) and Staphylococcus aureus (MIC_50/90, 0.5/0.5 μg/ml), but had limited activity against Enterococcus spp. (MIC_50/90, 16/64 μg/ml) and Streptococcus pneumoniae (MIC_50/90, 32/64 μg/ml). Plazomicin activity against the Enterobacteriaceae tested, including CRE and isolates carrying bla_KPC from U.S. hospitals, support the development plan for plazomicin to treat serious infections caused by resistant Enterobacteriaceae in patients with limited treatment options.

https://ift.tt/2sGchy6

Activities of oxadiazole antibacterials against Staphylococcus aureus and other Gram-positive bacteria [PublishAheadOfPrint]

The activities of four oxadiazoles were investigated with 210 methicillin-resistant Staphylococcus aureus (MRSA) strains. MIC₅₀ and MIC₉₀ values of 1-2 and 4 μg/ml, respectively, were observed. We also evaluated the activity of oxadiazole ND-421 against other staphylococci and enterococci and in the presence of oxacillin for selected MRSA. The MIC for ND-421 is lowered several fold in combination with oxacillin, as they synergize. The MIC₉₀ of ND-421 against vancomycin-resistant enterococci (VRE) is ≤1 μg/ml.

https://ift.tt/2kMHoEt

PET-PCR for Detection of Plasmodium falciparum Plasmepsin 2 Gene copy number [PublishAheadOfPrint]

Piperaquine is an important partner drug used in artemisinin-based combination therapies (ACTs). An increase in the plasmepsin 2 and 3 gene copy number has been associated with decreased susceptibility of Plasmodium falciparum to piperaquine in Cambodia. Here, we developed a photo- induced electron transfer real-time PCR (PET-PCR) assay to quantify the copy number of plasmepsin 2 (PfPM2) that can be used in endemic countries to enhance molecular surveillance.

https://ift.tt/2sB4gKG

Primary fungal prophylaxis in hematological malignancy: A network meta-analysis of randomized controlled trials [PublishAheadOfPrint]

Several new anti-fungal agents have become available for primary fungal prophylaxis of neutropenia fever in haematological malignancy patients. Our aim was to synthesize all evidence on efficacy and enable an integrated comparison of all current treatments.

We performed a systematic literature review to identify all publicly available evidence from randomized controlled trials (RCT). We searched Embase, PubMed, the Cochrane Central Register of Controlled Clinical Trials, and the website www.ClinicalTrials.gov. In total, 54 RCTs were identified, including 13 treatment options. The evidence was synthesised using a network meta-analysis. Relative risk (RR) was adopted.

Posaconazole was ranked highest effectiveness for primary prophylaxis, being the most favorable in terms of (1) the RR for reduction of invasive fungal infection (0.19; 95% confidence interval (CI): 0.11–0.36) and (2) the probability of being the best (94% of the cumulative ranking). Posaconazole also demonstrated its efficacy in preventing invasive aspergillosis and proven fungal infections, with RR of 0.13 (CI: 0.03–0.65) and 0.14 (CI: 0.05–0.38), respectively. However, there was no significant difference among all the anti-fungal agents in all-cause mortality and overall adverse events.

Our network meta-analysis provided an integrated overview of the relative efficacy of all available treatment options for primary fungal prophylaxis for neutropenic fever in hematological malignancy patients under myelosuppressive chemotherapy or hematopoietic cell transplantation. On the basis of this analysis, Posaconazole seems to be the most effectiveness prophylaxis option until additional data from head-to-head randomized controlled trials become available.

https://ift.tt/2kNxNxa

Linezolid Kills Acid Phase and Non-replicative Persister Phase Mycobacterium tuberculosis in a Hollow Fiber Infection Model [PublishAheadOfPrint]

The therapy of Mycobacterium tuberculosis (MTB) infection is long and arduous. It has been hypothesized that the therapy duration is driven primarily by populations of organisms in different metabolic states that replicate slowly or not at all (Acid-phase and NRP-phase organisms). Linezolid is an oxazolidinone antimicrobial with substantial activity against Log-phase MTB. Here, we examined organisms in Acid-phase growth and Non-Replicative Persister phenotype growth and determined the effect of differing clinically-relevant exposures to linezolid in a Hollow Fiber Infection Model (HFIM). The endpoints measured were bacterial kill over 29 days and whether organisms less-susceptible to linezolid could be recovered during this period. In addition, we evaluated the effect of administration schedule on linezolid activity, contrasting daily administration with twice the daily dose administered every other day. Linezolid demonstrated robust activity when administered daily against both Acid-phase and NRP-phase organisms. We demonstrated a clear dose response, with 900 mg of linezolid daily generating ≥ 3 Log(CFU/ml) killing of Acid-phase and NRP-phase MTB bacterial kill over 29 days. Amplification of a population less susceptible to linezolid was not seen. Activity was reduced with every 48-hour dosing, indicating that C_min/MIC ratio drove microbiological effect. We conclude that once-daily linezolid has substantial activity against MTB in Acid-phase and NRP-phase metabolic states. Other studies have shown activity versus Log-phase MTB. Linezolid is a valuable addition to the therapeutic armamentarium for MTB and has the potential for substantially shortening therapy duration.

https://ift.tt/2HkE5NN

Model system identifies kinetic driver of Hsp90 inhibitor activity against African trypanosomes and Plasmodium falciparum [PublishAheadOfPrint]

Hsp90 inhibitors, well-studied in the laboratory and clinic for antitumor indications, have promising activity against protozoan pathogens, including Trypanosoma brucei that causes African sleeping sickness, and malaria parasite Plasmodium falciparum. To progress these experimental drugs toward clinical use we adapted an in vitro dynamic hollow-fiber system and deployed artificial pharmacokinetics to discover the driver of their activity: either concentration or time. Compounds from three major classes of Hsp90 inhibitors in development were evaluated against trypanosomes. In all circumstances tested Hsp90 inhibitors were concentration-driven. By optimally deploying the drug to match kinetic driver, efficacy of a given dose was improved up to five-fold, and maximal efficacy was achieved with a significantly lower drug exposure. The superiority of concentration-driven regimens was evident in vitro over several logs of drug exposure, and was predictive of efficacy in a mouse model of African trypanosomiasis. In studies with P. falciparum, antimalarial activity was similarly concentration-driven. This experimental strategy offers an expedient and versatile translational tool to assess the impact of pharmacokinetics on antiprotozoal activity. Knowing kinetic governance early in drug development provides an additional metric for judging lead compounds and allows incisive design of animal efficacy studies.

https://ift.tt/2kNxEtC

Proposing Kluyvera georgiana as the origin of the plasmid-mediated resistance gene fosA4 [PublishAheadOfPrint]

A putative fosA gene in Kluyvera georgiana 14751 showed 99% nucleotide identity with plasmid-encoded fosA4. Due to a single-nucleotide insertion translating to a truncated protein, K. georgiana 14751 fosA does not confer fosfomycin resistance. Nonetheless, analysis of another genome deposit (K. ascorbata WCH1410) that could be recategorized as K. georgiana after phylogenetic analysis, revealed a fosA 100% identical to the plasmid-borne fosA4. Collectively, we suggest that Kluyvera georgiana represents the most probable origin of fosA4.

https://ift.tt/2sHvBLd

Correlation between gonial angle and dynamic tongue collapse in children with snoring/sleep disordered breathing – an exploratory pilot study

Drug induced sleep endoscopy (DISE) is hoped to identify reasons of failure of adenotonsillectomy (AT) in treating pediatric sleep disordered breathing (SDB). Maxillomandibular disproportion has been studied a...

https://ift.tt/2xObMaK

Cross-sectional study on sensitization to mite and cockroach allergen components in allergy patients in the Central European region

The major sources of allergens in the indoor air include house dust mites, dander derived from domestic animals and rodents, cockroach, and several fungi. Mites are the main cause of allergies in some countrie...

https://ift.tt/2sGWAXg

Immune checkpoint-mediated myositis and myasthenia gravis: A case report and review of evaluation and management

We present a case of myositis and possible overlapping neuromuscular junction disorder following treatment with nivolumab for recurrent/metastatic head and neck squamous cell carcinoma (HNSCC).

https://ift.tt/2LnAlgD

Outcomes in microvascular head and neck reconstruction in the setting of restricted residency hours

Resident duty hour restrictions can limit the frequency of resident flap checks at smaller institutions with "home" call. Institutions are compensating with adjuvant nursing flap checks as well as incorporating technology; however, this management remains controversial.

https://ift.tt/2JvxfKn

Comparison of intratympanic dexamethasone therapy and hyperbaric oxygen therapy for the salvage treatment of refractory high-frequency sudden sensorineural hearing loss

This study aimed to compare the efficacy of intratympanic dexamethasone (ITD) therapy and hyperbaric oxygen(HBO) therapy for the salvage treatment of patients with high-frequency sudden sensorineural hearing loss (SSNHL) after the failure of conventional therapy.

https://ift.tt/2LmD620

A computed tomographic analysis of frontal recess cells in association with the development of frontal sinusitis

This study was done to determine frontal recess anatomy cell variations and its association with frontal sinusitis. The incidence of frontal recess cells in the population, the presence of frontal recess cell variations in chronic rhinosinusitis and non-chronic rhinosinusitis and the association of frontal recess cell variation in the development of frontal sinusitis were also assessed.

https://ift.tt/2LicA9V

Role of Complement in a Rat Model of Paclitaxel-Induced Peripheral Neuropathy [INNATE IMMUNITY AND INFLAMMATION]

Chemotherapy-induced peripheral neuropathy (CIPN) is a painful and debilitating side effect of cancer chemotherapy with an unclear pathogenesis. Consequently, the available therapies for this neuropathic pain syndrome are inadequate, leading to a significantly reduced quality of life in many patients. Complement, a key component of the innate immune system, has been associated with neuroinflammation, a potentially important trigger of some types of neuropathic pain. However, the role of complement in CIPN remains unclear. To address this issue, we developed a C3 knockout (KO) rat model and induced CIPN in these KO rats and wild-type littermates via the i.p. administration of paclitaxel, a chemotherapeutic agent associated with CIPN. We then compared the severity of mechanical allodynia, complement activation, and intradermal nerve fiber loss between the groups. We found that 1) i.p. paclitaxel administration activated complement in wild-type rats, 2) paclitaxel-induced mechanical allodynia was significantly reduced in C3 KO rats, and 3) the paclitaxel-induced loss of intradermal nerve fibers was markedly attenuated in C3 KO rats. In in vitro studies, we found that paclitaxel-treated rat neuronal cells activated complement, leading to cellular injury. Our findings demonstrate a previously unknown but pivotal role of complement in CIPN and suggest that complement may be a new target for the development of novel therapeutics to manage this painful disease.

https://ift.tt/2LZTV3F

eIF4E-Binding Proteins 1 and 2 Limit Macrophage Anti-Inflammatory Responses through Translational Repression of IL-10 and Cyclooxygenase-2 [INNATE IMMUNITY AND INFLAMMATION]

Macrophages represent one of the first lines of defense during infections and are essential for resolution of inflammation following pathogen clearance. Rapid activation or suppression of protein synthesis via changes in translational efficiency allows cells of the immune system, including macrophages, to quickly respond to external triggers or cues without de novo mRNA synthesis. The translational repressors eIF4E-binding proteins 4E-BP1 and 4E-BP2 (4E-BP1/2) are central regulators of proinflammatory cytokine synthesis during viral and parasitic infections. However, it remains to be established whether 4E-BP1/2 play a role in translational control of anti-inflammatory responses. By comparing translational efficiencies of immune-related transcripts in macrophages from wild-type and 4E-BP1/2 double-knockout mice, we found that translation of mRNAs encoding two major regulators of inflammation, IL-10 and PG-endoperoxide synthase 2/cyclooxygenase-2, is controlled by 4E-BP1/2. Genetic deletion of 4E-BP1/2 in macrophages increased endogenous IL-10 and PGE₂ protein synthesis in response to TLR4 stimulation and reduced their bactericidal capacity. The molecular mechanism involves enhanced anti-inflammatory gene expression (sIl1ra, Nfil3, Arg1, Serpinb2) owing to upregulation of IL-10–STAT3 and PGE₂–C/EBPβ signaling. These data provide evidence that 4E-BP1/2 limit anti-inflammatory responses in macrophages and suggest that dysregulated activity of 4E-BP1/2 might be involved in reprogramming of the translational and downstream transcriptional landscape of macrophages during pathological conditions, such as infections and cancer.

https://ift.tt/2JgLcIJ

RNF31 Regulates Skin Homeostasis by Protecting Epidermal Keratinocytes from Cell Death [INNATE IMMUNITY AND INFLAMMATION]

Linear ubiquitin chain assembly complex plays an important role in regulating TNF-α signaling activation by modifying target proteins with linear (M1-linked) ubiquitin chains. In this study, we report that the epidermis-specific knockout (KO) of RNF31, the catalytic subunit of linear ubiquitin chain assembly complex, results in an early postnatal lethality in mice due to severe skin inflammation. The inflammation was mainly triggered by TNF-α–induced apoptosis in RNF31 KO keratinocytes. Mechanistically, the deficiency of RNF31 not only impaired TNF-α–induced NF-B activation, but also significantly increased apoptosis. Consistently, deleting TNF receptor 1 could rescue the lethality of RNF31 epidermis-specific KO mice and also the skin inflammation. Collectively, our study provides an in vivo insight that linear ubiquitination is critical for maintaining the homeostasis of keratinocytes, which will shed light on designing therapeutic compounds to treat skin inflammation.

https://ift.tt/2LXvyUt

Integrin Activation Controls Regulatory T Cell-Mediated Peripheral Tolerance [IMMUNE REGULATION]

Maintenance of the regulatory T (Treg) cell pool is essential for peripheral tolerance and prevention of autoimmunity. Integrins, heterodimeric transmembrane proteins consisting of α and β subunits that mediate cell-to-cell and cell-to-extracellular matrix interactions, play an important role in facilitating Treg cell contact–mediated suppression. In this article, we show that integrin activation plays an essential, previously unappreciated role in maintaining murine Treg cell function. Treg cell–specific loss of talin, a β integrin–binding protein, or expression of talin(L325R), a mutant that selectively abrogates integrin activation, resulted in lethal systemic autoimmunity. This dysfunction could be attributed, in part, to a global dysregulation of the Treg cell transcriptome. Activation of integrin α₄β₁ led to increased suppressive capacity of the Treg cell pool, suggesting that modulating integrin activation on Treg cells may be a useful therapeutic strategy for autoimmune and inflammatory disorders. Taken together, these results reveal a critical role for integrin-mediated signals in controlling peripheral tolerance by virtue of maintaining Treg cell function.

https://ift.tt/2LWQQlf

MicroRNA-155 Modulates Acute Graft-versus-Host Disease by Impacting T Cell Expansion, Migration, and Effector Function [TRANSPLANTATION]

MicroRNA-155 (miR-155) is a small noncoding RNA critical for the regulation of inflammation as well as innate and adaptive immune responses. MiR-155 has been shown to be dysregulated in both donor and recipient immune cells during acute graft-versus-host disease (aGVHD). We previously reported that miR-155 is upregulated in donor T cells of mice and humans with aGVHD and that mice receiving miR-155–deficient (miR155^–/–) splenocytes had markedly reduced aGVHD. However, molecular mechanisms by which miR-155 modulates T cell function in aGVHD have not been fully investigated. We identify that miR-155 expression in both donor CD8⁺ T cells and conventional CD4⁺ CD25^– T cells is pivotal for aGVHD pathogenesis. Using murine aGVHD transplant experiments, we show that miR-155 strongly impacts alloreactive T cell expansion through multiple distinct mechanisms, modulating proliferation in CD8⁺ donor T cells and promoting exhaustion in donor CD4⁺ T cells in both the spleen and colon. Additionally, miR-155 drives a proinflammatory Th1 phenotype in donor T cells in these two sites, and miR-155^–/– donor T cells are polarized toward an IL-4–producing Th2 phenotype. We further demonstrate that miR-155 expression in donor T cells regulates CCR5 and CXCR4 chemokine-dependent migration. Notably, we show that miR-155 expression is crucial for donor T cell infiltration into multiple target organs. These findings provide further understanding of the role of miR-155 in modulating aGVHD through T cell expansion, effector cytokine production, and migration.

https://ift.tt/2xGHEOK

SOCS1 and SOCS3 Target IRF7 Degradation To Suppress TLR7-Mediated Type I IFN Production of Human Plasmacytoid Dendritic Cells [IMMUNE REGULATION]

Type I IFN production of plasmacytoid dendritic cells (pDCs) triggered by TLR-signaling is an essential part of antiviral responses and autoimmune reactions. Although it was well-documented that members of the cytokine signaling (SOCS) family regulate TLR-signaling, the mechanism of how SOCS proteins regulate TLR7-mediated type I IFN production has not been elucidated yet. In this article, we show that TLR7 activation in human pDCs induced the expression of SOCS1 and SOCS3. SOCS1 and SOCS3 strongly suppressed TLR7-mediated type I IFN production. Furthermore, we demonstrated that SOCS1- and SOCS3-bound IFN regulatory factor 7, a pivotal transcription factor of the TLR7 pathway, through the SH2 domain to promote its proteasomal degradation by lysine 48-linked polyubiquitination. Together, our results demonstrate that SOCS1/3-mediated degradation of IFN regulatory factor 7 directly regulates TLR7 signaling and type I IFN production in pDCs. This mechanism might be targeted by therapeutic approaches to either enhance type I IFN production in antiviral treatment or decrease type I IFN production in the treatment of autoimmune diseases.

https://ift.tt/2JgIhQm

Regulation of the DNA Repair Complex during Somatic Hypermutation and Class-Switch Recombination [MOLECULAR AND STRUCTURAL IMMUNOLOGY]

B lymphocytes optimize Ab responses by somatic hypermutation (SH), which introduces point mutations in the variable regions of the Ab genes and by class-switch recombination (CSR), which changes the expressed C region exon of the IgH. These Ab diversification processes are initiated by the deaminating enzyme activation-induced cytidine deaminase followed by many DNA repair enzymes, ultimately leading to deletions and a high mutation rate in the Ab genes, whereas DNA lesions made by activation-induced cytidine deaminase are repaired with low error rate on most other genes. This indicates an advanced regulation of DNA repair. In this study, we show that initiation of Ab diversification in B lymphocytes of mouse spleen leads to formation of a complex between many proteins in DNA repair. We show also that BCR activation, which signals the end of successful SH, reduces interactions between some proteins in the complex and increases other interactions in the complex with varying kinetics. Furthermore, we show increased localization of SH- and CSR-coupled proteins on switch regions of the Igh locus upon initiation of SH/CSR and differential changes in the localization upon BCR signaling, which terminates SH. These findings provide early evidence for a DNA repair complex or complexes that may be of functional significance for carrying out essential roles in SH and/or CSR in B cells.

https://ift.tt/2JjP1x2

Previously Hidden Dynamics at the TCR-Peptide-MHC Interface Revealed [MOLECULAR AND STRUCTURAL IMMUNOLOGY]

A structural characterization of the interaction between αβ TCRs and cognate peptide–MHC (pMHC) is central to understanding adaptive T cell–mediated immunity. X-ray crystallography, although the source of much structural data, traditionally provides only a static snapshot of the protein. Given the emerging evidence for the important role of conformational dynamics in protein function, we interrogated 309 crystallographic structures of pMHC complexes using ensemble refinement, a technique that can extract dynamic information from the x-ray data. Focusing on a subset of human pMHC class I systems, we found that in many cases, ensemble methods were able to uncover previously hidden evidence of significant conformational plasticity, thereby revealing additional information that can build upon and significantly enhance functional interpretations that are based on a single static structure. Notable examples include the interpretation of differences in the disease association of HLA subtypes, the relationship between peptide prominence and TCR recognition, the role of conformational flexibility in vaccine design, and the discrimination between induced fit and conformational selection models of TCR binding. We show that the currently widespread practice of analyzing pMHC interactions via the study of a single crystallographic structure does not make use of pertinent and easily accessible information from x-ray data concerning alternative protein conformations. This new analysis therefore not only highlights the capacity for ensemble methods to significantly enrich the interpretation of decades of structural data but also provides previously missing information concerning the dynamics of existing characterized TCR–pMHC interactions.

https://ift.tt/2LVbj9P

Comparative Transcriptomic Response of Primary and Immortalized Macrophages to Murine Norovirus Infection [SYSTEMS IMMUNOLOGY]

Murine norovirus (NoV) is genetically similar to human NoV and offers both an efficient in vitro cell culture system and an animal model by which to investigate the molecular basis of replication. In this study, we present a detailed global view of host alterations to cellular pathways that occur during the progression of a NoV infection. This was accomplished for both Mus musculus BALB/c–derived RAW264.7 (RAW) cells, an immortalized cell line widely used in in vitro replication studies, and primary bone marrow–derived macrophages (BMDM), representing a permissive in vivo target cell in the host. Murine NoV replicated in both cell types, although detected genome copies were approximately one log lower in BMDM compared with RAW cells. RAW and BMDM cells shared an IRF3/7-based IFN response that occurred early in infection. In RAW cells, transcriptional upregulation and INF-β expression were not coupled in that a significant delay in the detection of secreted INF-β was observed. In contrast, primary BMDM showed an early upregulation of transcripts and immediate release of INF-β that might account for lower virus yield. Differences in the transcriptional pathway responses included a marked decrease in expression of key genes in the cell cycle and lipid pathways in RAW cells compared with that of BMDM. Our comparative analysis indicates the existence of varying host responses to virus infection in populations of permissive cells. Awareness of these differences at the gene level will be important in the application of a given permissive culture system to the study of NoV immunity, pathogenesis, and drug development.

https://ift.tt/2LZTPsP

Platelet-Activating Factor-Induced Reduction in Contact Hypersensitivity Responses Is Mediated by Mast Cells via Cyclooxygenase-2-Dependent Mechanisms [IMMUNE REGULATION]

Platelet-activating factor (PAF) stimulates numerous cell types via activation of the G protein–coupled PAF receptor (PAFR). PAFR activation not only induces acute proinflammatory responses, but it also induces delayed systemic immunosuppressive effects by modulating host immunity. Although enzymatic synthesis and degradation of PAF are tightly regulated, oxidative stressors, such as UVB, chemotherapy, and cigarette smoke, can generate PAF and PAF-like molecules in an unregulated fashion via the oxidation of membrane phospholipids. Recent studies have demonstrated the relevance of the mast cell (MC) PAFR in PAFR-induced systemic immunosuppression. The current study was designed to determine the exact mechanisms and mediators involved in MC PAFR-mediated systemic immunosuppression. By using a contact hypersensitivity model, the MC PAFR was not only found to be necessary, but also sufficient to mediate the immunosuppressive effects of systemic PAF. Furthermore, activation of the MC PAFR induces MC-derived histamine and PGE₂ release. Importantly, PAFR-mediated systemic immunosuppression was defective in mice that lacked MCs, or in MC-deficient mice transplanted with histidine decarboxylase– or cyclooxygenase-2–deficient MCs. Lastly, it was found that PGs could modulate MC migration to draining lymph nodes. These results support the hypothesis that MC PAFR activation promotes the immunosuppressive effects of PAF in part through histamine- and PGE₂-dependent mechanisms.

https://ift.tt/2xR3KOL

Chronic Lymphocytic Leukemia-Derived IL-10 Suppresses Antitumor Immunity [TUMOR IMMUNOLOGY]

Chronic lymphocytic leukemia (CLL) patients progressively develop an immunosuppressive state. CLL patients have more plasma IL-10, an anti-inflammatory cytokine, than healthy controls. In vitro human CLL cells produce IL-10 in response to BCR cross-linking. We used the transgenic Eμ–T cell leukemia oncogene-1 (TCL1) mouse CLL model to study the role of IL-10 in CLL associated immunosuppression. Eμ-TCL mice spontaneously develop CLL because of a B cell–specific expression of the oncogene, TCL1. Eμ-TCL1 mouse CLL cells constitutively produce IL-10, which is further enhanced by BCR cross-linking, CLL-derived IL-10 did not directly affect survival of murine or human CLL cells in vitro. We tested the hypothesis that the CLL-derived IL-10 has a critical role in CLL disease in part by suppressing the host immune response to the CLL cells. In IL-10R^–/– mice, wherein the host immune cells are unresponsive to IL-10–mediated suppressive effects, there was a significant reduction in CLL cell growth compared with wild type mice. IL-10 reduced the generation of effector CD4 and CD8 T cells. We also found that activation of BCR signaling regulated the production of IL-10 by both murine and human CLL cells. We identified the transcription factor, Sp1, as a novel regulator of IL-10 production by CLL cells and that it is regulated by BCR signaling via the Syk/MAPK pathway. Our results suggest that incorporation of IL-10 blocking agents may enhance current therapeutic regimens for CLL by potentiating host antitumor immune response.

https://ift.tt/2LXvzI1

The ITIM Domain-Containing NK Receptor Ly49Q Impacts Pulmonary Infection by Mediating Neutrophil Functions [INNATE IMMUNITY AND INFLAMMATION]

Pulmonary infection is a frequent pathology associated with excessive neutrophil infiltration. Ly49Q, an ITIM domain–bearing receptor expressed on different leukocytes, has been recently reported to impact neutrophil migration and polarization. Utilizing a murine model of Klebsiella pneumoniae–induced pulmonary infection in combination with additional in vivo and in vitro assays, we show that Ly49Q is critically involved in different steps of the leukocyte adhesion cascade. Ly49Q deficiency is associated with a reduced rolling velocity, impaired crawling capacity, and diminished transmigration. We show that overactivation of the neutrophil β₂ integrins Mac-1 and LFA-1 is responsible for increased adhesion and reduced neutrophil transmigration, resulting in a strongly impaired immune defense against pulmonary infection. Structure function analysis in vitro and in vivo demonstrated that different domains of Ly49Q are important for its function. In summary, Ly49Q regulates integrin activation and neutrophil recruitment and is required for an adequate immune response in pulmonary infection.

https://ift.tt/2xIch6t

Rapid Turnover and High Production Rate of Myeloid Cells in Adult Rhesus Macaques with Compensations during Aging [IMMUNE SYSTEM DEVELOPMENT]

Neutrophils, basophils, and monocytes are continuously produced in bone marrow via myelopoiesis, circulate in blood, and are eventually removed from circulation to maintain homeostasis. To quantitate the kinetics of myeloid cell movement during homeostasis, we applied 5-bromo-2'-deoxyuridine pulse labeling in healthy rhesus macaques (Macaca mulatta) followed by hematology and flow cytometry analyses. Results were applied to a mathematical model, and the blood circulating half-life and daily production, respectively, of each cell type from macaques aged 5–10 y old were calculated for neutrophils (1.63 ± 0.16 d, 1.42 x 10⁹ cells/l/d), basophils (1.78 ± 0.30 d, 5.89 x 10⁶ cells/l/d), and CD14⁺CD16^– classical monocytes (1.01 ± 0.15 d, 3.09 x 10⁸ cells/l/d). Classical monocytes were released into the blood circulation as early as 1 d after dividing, whereas neutrophils remained in bone marrow 4–5 d before being released. Among granulocytes, neutrophils and basophils exhibited distinct kinetics in bone marrow maturation time and blood circulation. With increasing chronological age, there was a significant decrease in daily production of neutrophils and basophils, but the half-life of these granulocytes remained unchanged between 3 and 19 y of age. In contrast, daily production of classical monocytes remained stable through 19 y of age but exhibited a significant decline in half-life. These results demonstrated relatively short half-lives and continuous replenishment of neutrophils, basophils, and classical monocytes during homeostasis in adult rhesus macaques with compensations observed during increasing chronological age.

https://ift.tt/2LZ9qZH

Antibodies Encoded by FCRL4-Bearing Memory B Cells Preferentially Recognize Commensal Microbial Antigens [CLINICAL AND HUMAN IMMUNOLOGY]

FCRL4, a low-affinity IgA Ab receptor with strong immunoregulatory potential, is an identifying feature of a tissue-based population of memory B cells (Bmem). We used two independent approaches to perform a comparative analysis of the Ag receptor repertoires of FCRL4⁺ and FCRL4^– Bmem in human tonsils. We determined that FCRL4⁺ Bmem displayed lower levels of somatic mutations in their Ag receptors compared with FCRL4^– Bmem but had similar frequencies of variable gene family usage. Importantly, Abs with reactivity to commensal microbiota were enriched in FCRL4⁺ cells, a phenotype not due to polyreactive binding characteristics. Our study links expression of the immunoregulatory FCRL4 molecule with increased recognition of commensal microbial Ags.

https://ift.tt/2JejWuh

Small Molecule Mimetics of {alpha}-Helical Domain of IRAK2 Attenuate the Proinflammatory Effects of IL-33 in Asthma-like Mouse Models [IMMUNE REGULATION]

IL-33 and its receptor ST2 play important roles in airway inflammation and contribute to asthma onset and exacerbation. The IL-33/ST2 signaling pathway recruits adapter protein myeloid differentiation primary response 88 (MyD88) to transduce intracellular signaling. MyD88 forms a complex with IL-R–associated kinases (IRAKs), IRAK4 and IRAK2, called the Myddosome (MyD88–IRAK4–IRAK2). The myddosome subsequently activates downstream NF-B and MAPKs p38 and JNK. We established an asthma-like mouse model by intratracheal administration of IL-33. The IL-33 model has a very similar phenotype compared with the OVA-induced mouse asthma model. The importance of MyD88 in the IL-33/ST2 signaling transduction was demonstrated by the MyD88 knockout mice, which were protected from the IL-33–induced asthma. We synthesized small molecule mimetics of the α-helical domain of IRAK2 with drug-like characteristics based on the recent advances in the designing of α-helix compounds. The mimetics can competitively interfere in the protein–protein interaction between IRAK2 and IRAK4, leading to disruption of Myddosome formation. A series of small molecules were screened using an NF-B promoter assay in vitro. The lead compound, 7004, was further studied in the IL-33–induced and OVA-induced asthma mouse models in vivo. Compound 7004 can inhibit the IL-33–induced NF-B activity, disrupt Myddosome formation, and attenuate the proinflammatory effects in asthma-like models. Our data indicate that the Myddosome may represent a novel intracellular therapeutic target for diseases in which IL-33/ST2 plays important roles, such as asthma and other inflammatory diseases.

https://ift.tt/2LZTZAr

IL-2 Enhances Gut Homing Potential of Human Naive Regulatory T Cells Early in Life [CLINICAL AND HUMAN IMMUNOLOGY]

Recent evidence suggests early environmental factors are important for gut immune tolerance. Although the role of regulatory T (Treg) cells for gut immune homeostasis is well established, the development and tissue homing characteristics of Treg cells in children have not been studied in detail. In this article, we studied the development and homing characteristics of human peripheral blood Treg cell subsets and potential mechanisms inducing homing molecule expression in healthy children. We found contrasting patterns of circulating Treg cell gut and skin tropism, with abundant β7 integrin⁺ Treg cells at birth and increasing cutaneous lymphocyte Ag (CLA⁺) Treg cells later in life. β7 integrin⁺ Treg cells were predominantly naive, suggesting acquisition of Treg cell gut tropism early in development. In vitro, IL-7 enhanced gut homing but reduced skin homing molecule expression in conventional T cells, whereas IL-2 induced a similar effect only in Treg cells. This effect was more pronounced in cord compared with adult blood. Our results suggest that early in life, naive Treg cells may be driven for gut tropism by their increased sensitivity to IL-2–induced β7 integrin upregulation, implicating a potential role of IL-2 in gut immune tolerance during this critical period of development.

https://ift.tt/2LVbjGR

An Unmutated IgM Response to the Vi Polysaccharide of Salmonella Typhi Contributes to Protective Immunity in a Murine Model of Typhoid [INFECTIOUS DISEASE AND HOST RESPONSE]

T cell–dependent B cell responses typically develop in germinal centers. Abs generated during such responses are isotype switched and have a high affinity to the Ag because of somatic hypermutation of Ab genes. B cell responses to purified polysaccharides are T cell independent and do not result in the formation of bona fide germinal centers, and the dominant Ab isotype produced during such responses is IgM with very few or no somatic mutations. Activation-induced cytidine deaminase (AID) is required for both somatic hypermutation and Ig isotype switching in humans and mice. To test the extent to which unmutated polysaccharide-specific IgM confers protective immunity, we immunized wildtype and AID^–/– mice with either heat-killed Salmonella enterica serovar Typhi (S. Typhi) or purified Vi polysaccharide (ViPS). We found that wildtype and AID^–/– mice immunized with heat-killed S. Typhi generated similar anti-ViPS IgM responses. As expected, wildtype, but not AID^–/– mice generated ViPS-specific IgG. However, the differences in the Ab-dependent killing of S. Typhi mediated by the classical pathway of complement activation were not statistically significant. In ViPS-immunized wildtype and AID^–/– mice, the ViPS-specific IgM levels and S. Typhi bactericidal Ab titers at 7 but not at 28 d postimmunization were also comparable. To test the protective immunity conferred by these immunizations, mice were challenged with a chimeric S. Typhimurium strain expressing ViPS. Compared with their naive counterparts, immunized wildtype and AID^–/– mice exhibited significantly reduced bacterial burden regardless of the route of infection. These data indicate that an unmutated IgM response to ViPS contributes to protective immunity to S. Typhi.

https://ift.tt/2LZTW7J

Simultaneous Presence of Non- and Highly Mutated Keyhole Limpet Hemocyanin (KLH)-Specific Plasmablasts Early after Primary KLH Immunization Suggests Cross-Reactive Memory B Cell Activation [CLINICAL AND HUMAN IMMUNOLOGY]

There are currently limited insights into the progression of human primary humoral immunity despite numerous studies in experimental models. In this study, we analyzed a primary and related secondary parenteral keyhole limpet hemocyanin (KLH) immunization in five human adults. The primary challenge elicited discordant KLH-specific serum and blood effector B cell responses (i.e., dominant serum KLH-specific IgG and IgM levels versus dominant KLH-specific IgA plasmablast frequencies). Single-cell IgH sequencing revealed early appearance of highly (>15 mutations) mutated circulating KLH-specific plasmablasts 2 wk after primary KLH immunization, with simultaneous KLH-specific plasmablasts carrying non- and low-mutated IgH sequences. The data suggest that the highly mutated cells might originate from cross-reactive memory B cells (mBCs) rather than from the naive B cell repertoire, consistent with previous reported mutation rates and the presence of KLH-reactive mBCs in naive vaccinees prior to immunization. Whereas upon secondary immunization, serum Ab response kinetics and plasmablast mutation loads suggested the exclusive reactivation of KLH-specific mBCs, we, however, detected only little clonal overlap between the peripheral KLH-specific secondary plasmablast IgH repertoire and the primary plasmablast and mBC repertoire, respectively. Our data provide novel mechanistic insights into human humoral immune responses and suggest that primary KLH immunization recruits both naive B cells and cross-reactive mBCs, whereas secondary challenge exclusively recruits from a memory repertoire, with little clonal overlap with the primary response.

https://ift.tt/2Jhky2k

Extracellular Histones Inhibit Complement Activation through Interacting with Complement Component 4 [INNATE IMMUNITY AND INFLAMMATION]

Complement activation leads to membrane attack complex formation, which can lyse not only pathogens but also host cells. Histones can be released from the lysed or damaged cells and serve as a major type of damage-associated molecular pattern, but their effects on the complement system are not clear. In this study, we pulled down two major proteins from human serum using histone-conjugated beads: one was C-reactive protein and the other was C4, as identified by mass spectrometry. In surface plasmon resonance analysis, histone H3 and H4 showed stronger binding to C4 than other histones, with K_D around 1 nM. The interaction did not affect C4 cleavage to C4a and C4b. Because histones bind to C4b, a component of C3 and C5 convertases, their activities were significantly inhibited in the presence of histones. Although it is not clear whether the inhibition was achieved through blocking C3 and C5 convertase assembly or just through reducing their activity, the outcome was that both classical and mannose-binding lectin pathways were dramatically inhibited. Using a high concentration of C4 protein, histone-suppressed complement activity could not be fully restored, indicating C4 is not the only target of histones in those pathways. In contrast, the alternative pathway was almost spared, but the overall complement activity activated by zymosan was inhibited by histones. Therefore, we believe that histones inhibiting complement activation is a natural feedback mechanism to prevent the excessive injury of host cells.

https://ift.tt/2JicBKy

Inability To Detect Cross-Reactive Memory T Cells Challenges the Frequency of Heterologous Immunity among Common Viruses [CLINICAL AND HUMAN IMMUNOLOGY]

Human memory T cells that cross-react with epitopes from unrelated viruses can potentially modulate immune responses to subsequent infections by a phenomenon termed heterologous immunity. However, it is unclear whether similarities in structure rather than sequence underpin heterologous T cell cross-reactivity. In this study, we aimed to explore the mechanism of heterologous immunity involving immunodominant epitopes derived from common viruses restricted to high-frequency HLA allotypes (HLA-A*02:01, -B*07:02, and -B*08:01). We examined EBV-specific memory T cells for their ability to cross-react with CMV or influenza A virus–derived epitopes. Following T cell immunoassays to determine phenotype and function, complemented with biophysical and structural investigations of peptide/HLA complexes, we did not detect cross-reactivity of EBV-specific memory T cells toward either CMV or influenza A virus epitopes presented by any of the selected HLA allomorphs. Thus, despite the ubiquitous nature of these human viruses and the dominant immune response directed toward the selected epitopes, heterologous virus-specific T cell cross-reactivity was not detected. This suggests that either heterologous immunity is not as common as previously reported, or that it requires a very specific biological context to develop and be clinically relevant.

https://ift.tt/2LShKdX

CD71+ Erythroid Suppressor Cells Promote Fetomaternal Tolerance through Arginase-2 and PDL-1 [IMMUNE REGULATION]

Survival of the allogeneic pregnancy depends on the maintenance of immune tolerance to paternal alloantigens at the fetomaternal interface. Multiple localized mechanisms contribute to the fetal evasion from the mother's immune rejection as the fetus is exposed to a wide range of stimulatory substances such as maternal alloantigens, microbes and amniotic fluids. In this article, we demonstrate that CD71⁺ erythroid cells are expanded at the fetomaternal interface and in the periphery during pregnancy in both humans and mice. These cells exhibit immunosuppressive properties, and their abundance is associated with a Th2 skewed immune response, as their depletion results in a proinflammatory immune response at the fetomaternal interface. In addition to their function in suppressing proinflammatory responses in vitro, maternal CD71⁺ erythroid cells inhibit an aggressive allogeneic response directed against the fetus such as reduction in TNF-α and IFN- production through arginase-2 activity and PD-1/programmed death ligand-1 (PDL-1) interactions. Their depletion leads to the failure of gestation due to the immunological rejection of the fetus. Similarly, fetal liver CD71⁺ erythroid cells exhibit immunosuppressive activity. Therefore, immunosuppression mediated by CD71⁺ erythroid cells on both sides (mother/fetus) is crucial for fetomaternal tolerance. Thus, our results reveal a previously unappreciated role for CD71⁺ erythroid cells in pregnancy and indicate that these cells mediate homeostatic immunosuppressive/immunoregulatory responses during pregnancy.

https://ift.tt/2xIcjeB

Case report presenting the diagnostic challenges in a patient with recurrent acquired angioedema, antiphospholipid antibodies and undetectable C2 levels

Angioedema secondary to acquired C1 inhibitor deficiency (AAE) is a rare disease. It usually is associated with lymphoproliferative disorders. We present a case of AAE in a patient with antiphospholipid syndro...

https://ift.tt/2JcjFw4

A computed tomographic analysis of frontal recess cells in association with the development of frontal sinusitis

Publication date: Available online 4 June 2018
Source:Auris Nasus Larynx
Author(s): Hafizah Husna Johari, Irfan Mohamad, Ida Sadja'ah Sachlin, Mohd Ezane Aziz, Teoh Yuen Mey, Ramiza Ramza Ramli
ObjectiveThis study was done to determine frontal recess anatomy cell variations and its association with frontal sinusitis. The incidence of frontal recess cells in the population, the presence of frontal recess cell variations in chronic rhinosinusitis and non-chronic rhinosinusitis and the association of frontal recess cell variation in the development of frontal sinusitis were also assessed.MethodsThis was an observational, retrospective cross-sectional study of computed tomography (CT) scan of paranasal sinus that had been performed on patients in Hospital Universiti Sains Malaysia and Hospital Sultanah Bahiyah done from January 2009 until December 2016. The presence of frontal recess cells variation was compared with other populations.ResultsA total of 312 sides from 156 patients' CT scan images were analyzed. Left and right sinuses were considered individually. A total of 63 sides showed evidence of frontal sinusitis, 37 were male and 26 were female, whereas 249 sides were clear from frontal sinus disease. It was not much difference in mean age for frontal sinusitis patient (46.51±14.00) and patients without frontal sinusitis (48.73±16.44). The percentage was almost equal for CRS and non-CRS groups regardless of side and gender. In our study, the frontal recess cell such as agger nasi cell was found in almost all patients 98.1%, frontal ethmoidal cell type 1, type 2, type 3 and type 4 comprised of 28.8%, 31.1%, 14.4% and 0% respectively. Whereas, suprabullar cell can be seen in 40.3%, supraorbital ethmoid cells 16.7%, frontal bullar cell 33.0% and inter-frontal sinus septal cells 10.8%. There was a statistically significant association between the presence of frontal bullar cell and the development of frontal sinusitis (p value<0.001).ConclusionThe frontal recess cells variation in Malaysian subjects were almost similar to those reported in other Asian populations such as Japanese, Taiwanese, Chinese and Korean. Our study found that frontal bullar cells had a significant association with the development of frontal sinusitis than other frontal recess cells. The understanding of the frontal recess anatomical structures was very important as this would lead to a successful treatment of CRS and at the same time it helped the surgeon to have a better plan of endoscopic sinus surgery to prevent the disease recurrence and surgical complication.



https://ift.tt/2JqUZ2l

Internal biliary drainage for isolated posterior segmental biliary obstruction: a case report

Biliary system anatomical abnormalities can be preoperatively detected on magnetic resonance imaging; therefore, some presume that the number of bile duct injuries should decline. However, once a bile duct inj...

https://ift.tt/2kMgvR6

Platelet-Derived Growth Factor Subunit B Signaling Promotes Pericyte Migration in Response to Loud Sound in the Cochlear Stria Vascularis

Abstract

Normal blood supply to the cochlea is critical for hearing. Noise damages auditory sensory cells and has a marked effect on the microvasculature in the cochlear lateral wall. Pericytes in the stria vascularis (strial pericytes) are particularly vulnerable and sensitive to acoustic trauma. Exposure of NG2DsRedBAC transgenic mice (6–8 weeks old) to wide-band noise at a level of 120 dB for 3 h per day for 2 consecutive days produced a significant hearing threshold shift and caused pericytes to protrude and migrate from their normal endothelial attachment sites. The pericyte migration was associated with increased expression of platelet-derived growth factor beta (PDGF-BB). Blockade of PDGF-BB signaling with either imatinib, a potent PDGF-BB receptor (PDGFR) inhibitor, or APB5, a specific PDGFRβ blocker, significantly attenuated the pericyte migration from strial vessel walls. The PDGF-BB-mediated strial pericyte migration was further confirmed in an in vitro cell migration assay, as well as in an in vivo live animal model used in conjunction with confocal fluorescence microscopy. Pericyte migration took one of two different forms, here denoted protrusion and detachment. The protrusion is characterized by pericytes with a prominent triangular shape, or pericytes extending fine strands to neighboring capillaries. The detachment is characterized by pericyte detachment and movement away from vessels. We also found the sites of pericyte migration highly associated with regions of vascular leakage. In particular, under transmission electron microscopy (TEM), multiple vesicles at the sites of endothelial cells with loosely attached pericytes were observed. These data show that cochlear pericytes are markedly affected by acoustic trauma, causing them to display abnormal morphology. The effect of loud sound on pericytes is mediated by upregulation of PDGF-BB. Normal functioning pericytes are required for vascular stability.

https://ift.tt/2J9DvYL

Psychophysical Tuning Curves as a Correlate of Electrode Position in Cochlear Implant Listeners

ABSTRACT

Speech understanding abilities vary widely among cochlear implant (CI) listeners. A potential source of this variability is the electrode-neuron interface (ENI), which includes peripheral factors such as electrode position and integrity of remaining spiral ganglion neurons. Suboptimal positioning of the electrode array has been associated with poorer speech outcomes; however, postoperative computerized tomography (CT) scans are often not available to clinicians. CT-estimated electrode-to-modiolus distance (distance from the inner wall of the cochlea) has been shown to account for some variability in behavioral thresholds. However, psychophysical tuning curves (PTCs) may provide additional insight into site-specific variation in channel interaction. Thirteen unilaterally implanted adults with the Advanced Bionics HiRes90K device participated. Behavioral thresholds and PTCs were collected for all available electrodes with steered quadrupolar (sQP) configuration, using a modified threshold sweep procedure, used in Bierer et al. (Trends Hear 19:1–12, 2015). PTC bandwidths were quantified to characterize channel interaction across the electrode array, and tip shifts were assessed to identify possible contributions of neural dead regions. Broader PTC bandwidths were correlated with electrodes farther from the modiolus, but not correlated with sQP threshold, though a trend was observed. Both measures were affected by scalar location, and PTC tip shifts were observed for electrodes farther from the modiolus. sQP threshold was the only variable correlated with word recognition. These results suggest PTCs may be used as a site-specific measure of channel interaction that correlates with electrode position in some CI listeners.

https://ift.tt/2sCqKuR

Characterization of Adult Vestibular Organs in 11 CreER Mouse Lines

Abstract

Utricles are vestibular sense organs that encode linear head movements. They are composed of a sensory epithelium with type I and type II hair cells and supporting cells, sitting atop connective tissue, through which vestibular nerves project. We characterized utricular Cre expression in 11 murine CreER lines using the ROSA26^tdTomato reporter line and tamoxifen induction at 6 weeks of age. This characterization included Calbindin2^CreERT2 , Fgfr3-iCreER^T2 , GFAP-A-CreER™, GFAP-B-CreER™, GLAST-CreER^T2 , Id2^CreERT2 , Otoferlin^CreERT2 , Parvalbumin^CreERT2 , Prox1^CreERT2 , Sox2^CreERT2 , and Sox9-CreER^T2 . Otoferlin^CreERT2 mice had inducible Cre activity specific to hair cells. GLAST-CreER^T2 , Id2^CreERT2 , and Sox9-CreER^T2 had inducible Cre activity specific to supporting cells. Sox2^CreERT2 had inducible Cre activity in supporting cells and most type II hair cells. Parvalbumin^CreERT2 mice had small numbers of labeled vestibular nerve afferents. Calbindin2^CreERT2 mice had labeling of most type II hair cells and some type I hair cells and supporting cells. Only rare (or no) tdTomato-positive cells were detected in utricles of Fgfr3-iCreER^T2 , GFAP-A-CreER™, GFAP-B-CreER™, and Prox1^CreERT2 mice. No Cre leakiness (tdTomato expression in the absence of tamoxifen) was observed in Otoferlin^CreERT2 mice. A small degree of leakiness was seen in GLAST-CreER^T2 , Id2^CreERT2 , Sox2^CreERT2 , and Sox9-CreER^T2 lines. Calbindin2^CreERT2 mice had similar tdTomato expression with or without tamoxifen, indicating lack of inducible control under the conditions tested. In conclusion, 5 lines—GLAST-CreER^T2 , Id2^CreERT2 , Otoferlin^CreERT2 , Sox2^CreERT2 , and Sox9-CreER^T2 —showed cell-selective, inducible Cre activity with little leakiness, providing new genetic tools for researchers studying the vestibular periphery.

https://ift.tt/2kOrgCg

Characterization of Adult Vestibular Organs in 11 CreER Mouse Lines

Abstract

Utricles are vestibular sense organs that encode linear head movements. They are composed of a sensory epithelium with type I and type II hair cells and supporting cells, sitting atop connective tissue, through which vestibular nerves project. We characterized utricular Cre expression in 11 murine CreER lines using the ROSA26^tdTomato reporter line and tamoxifen induction at 6 weeks of age. This characterization included Calbindin2^CreERT2 , Fgfr3-iCreER^T2 , GFAP-A-CreER™, GFAP-B-CreER™, GLAST-CreER^T2 , Id2^CreERT2 , Otoferlin^CreERT2 , Parvalbumin^CreERT2 , Prox1^CreERT2 , Sox2^CreERT2 , and Sox9-CreER^T2 . Otoferlin^CreERT2 mice had inducible Cre activity specific to hair cells. GLAST-CreER^T2 , Id2^CreERT2 , and Sox9-CreER^T2 had inducible Cre activity specific to supporting cells. Sox2^CreERT2 had inducible Cre activity in supporting cells and most type II hair cells. Parvalbumin^CreERT2 mice had small numbers of labeled vestibular nerve afferents. Calbindin2^CreERT2 mice had labeling of most type II hair cells and some type I hair cells and supporting cells. Only rare (or no) tdTomato-positive cells were detected in utricles of Fgfr3-iCreER^T2 , GFAP-A-CreER™, GFAP-B-CreER™, and Prox1^CreERT2 mice. No Cre leakiness (tdTomato expression in the absence of tamoxifen) was observed in Otoferlin^CreERT2 mice. A small degree of leakiness was seen in GLAST-CreER^T2 , Id2^CreERT2 , Sox2^CreERT2 , and Sox9-CreER^T2 lines. Calbindin2^CreERT2 mice had similar tdTomato expression with or without tamoxifen, indicating lack of inducible control under the conditions tested. In conclusion, 5 lines—GLAST-CreER^T2 , Id2^CreERT2 , Otoferlin^CreERT2 , Sox2^CreERT2 , and Sox9-CreER^T2 —showed cell-selective, inducible Cre activity with little leakiness, providing new genetic tools for researchers studying the vestibular periphery.

https://ift.tt/2kOrgCg

Bispecific light T-cell engagers for gene-based immunotherapy of epidermal growth factor receptor (EGFR)-positive malignancies

Abstract

The recruitment of T-cells by bispecific antibodies secreted from adoptively transferred, gene-modified autologous cells has shown satisfactory results in preclinical cancer models. Even so, the approach's translation into the clinic will require incremental improvements to its efficacy and reduction of its toxicity. Here, we characterized a tandem T-cell recruiting bispecific antibody intended to benefit gene-based immunotherapy approaches, which we call the light T-cell engager (LiTE), consisting of an EGFR-specific single-domain V_HH antibody fused to a CD3-specific scFv. We generated two LiTEs with the anti-EGFR V_HH and the anti-CD3 scFv arranged in both possible orders. Both constructs were well expressed in mammalian cells as highly homogenous monomers in solution with molecular weights of 43 and 41 kDa, respectively. In situ secreted LiTEs bound the cognate antigens of both parental antibodies and triggered the specific cytolysis of EGFR-expressing cancer cells without inducing T-cell activation and cytotoxicity spontaneously or against EGFR-negative cells. Light T-cell engagers are, therefore, suitable for future applications in gene-based immunotherapy approaches.

https://ift.tt/2LUUUCm

New approach to immunotherapy leads to complete response in breast cancer patient unresponsive to other treatments

A novel approach to immunotherapy developed by NCI researchers has led to the complete regression of breast cancer in a patient who was unresponsive to all other treatments. The findings were published in Nature Medicine.

https://ift.tt/2kOpnpy

Completely Endoscopic Approach Using a Skeeter Drill to Treat Bilateral Congenital Choanal Atresia in a 33 Week Born Pre-term Baby

Abstract

Choanal atresia (CA) is a relatively rare condition manifesting with respiratory distress. Endoscopic approaches have superseded transnasal and transpalatal approaches. We present a case of a premature baby of 1.10 kg, who developed respiratory distress and was diagnosed with bilateral CA. A nasal airway was created endoscopically using a skeeter drill.

https://ift.tt/2JaOuBc

Voice Change Following Adenotonsillectomy in Pediatric Population: Myth or Reality?—A Pilot Study

Abstract

Modifications in the structure of pharynx following adenotonsillectomy are presumed to cause changes in the voice characteristics of patients. Data on effect of tonsillectomy/adenotonsillectomy on changes in voice among Indian children are sparse. This study was thus conducted to study the effect of adenotonsillectomy/tonsillectomy on childrens' voice. It was a prospective observational study of children aged 4–15 years undergoing tonsillectomy with or without adenoidectomy. Measures of voice were noted preoperatively, 1 and 3 months post-operatively. Subjective evaluation was done using Paediatric Voice Outcome Survey (PVOS) questionnaire administered to participants' parents. Objective evaluation was done by recording and analyzing using PRAAT voice analysis software which is an open-software tool. Statistical analysis was done using the statistical software SPSS 17.0 version. There were 31 children between 4 and 14 years of age 65% being male. Adenotonsillectomy was done in 83.5%. There was statistically significant difference in the subjective scores (PVOS) pre-operatively and 3 month postoperative score (p value = 0.001). However, there was no statistically significant difference between any other pre op and post op parameters. Though the only significant post tonsillectomy voice changes noted was subjective by parents 3 months later, it does raise concern whether this could be a reality and not a myth. Further studies with larger number of patients, including involving the subjective evaluation (PVOS) by another person in addition to patients' parent need to be undertaken to address this issue.

https://ift.tt/2HjZ57f

Management of Head and Neck Hemangiomas in Adults: Oral Propranolol Versus Oral Itraconazole in Conjugation with Injection Sodium Tetra Decyl Sulphate

Abstract

Management of head and neck hemangiomas with oral propranolol versus oral itraconazole in conjugation with injection sodium tetra decyl sulphate. This prospective parallel clinical trial was done to check for the effectiveness of oral propranolol and oral itraconazole when used in conjugation with inj. sodium tetra decyl sulphate in treatment of head and neck haemangiomas in adult patients visiting department of ENT and head and neck surgery, VIMSAR, Burla. All the patients visiting the department with hemangioma (diagnosed clinically and by FNAC) were considered and only those who gave written informed consent and were according to our inclusion and exclusion criteria were included into the study as subjects. Dimension (length, width and hemi-circumference) of the haemangiomas were measured using disposable paper taper measures. Depth of the hemangioma was calculated based on formula and using that volume was calculated both at baseline and after 8 weeks of drug administration. Data so collected was entered into Microsoft Office Excel 2013 and statistical analysis was performed using SPSS Version 20.0. Descriptive statistics was calculated and student's t test (paired and unpaired) was used to compare within the group (before and after) and between the groups respectively. Statistical significance was set at p ≤ 0.05. Both the groups showed statistically significant volume reduction in the lesions [p < 0.018 (propranolo + sodium tetra decyl sulphate), p < 0.025 (itraconazole + sodium tetra decyl sulphate)]. The mean decrease in volume in propranolol group was 91.92% and that in itraconazole group was 88.97%. There was no statistical difference between the final outcome of both the groups (p < 0.766) but 3 patients on propranolol had complete resolution while 1 patient on itraconazole had complete resolution of the lesion. Oral propranolol and itraconazole are both effective and safe in hemangioma in adults. The combination with inj. sodium tetra decyl sulphate has a (1) favorable impact on decreasing the overall duration of treatment. (2) Aiding in complete resolution of lesions (especially < 3 cm). Propranolol has an edge over itraconazole (more no of tumors had complete resolution).

https://ift.tt/2J8HEMK

Tumor-derived exosomes, microRNAs, and cancer immune suppression

Abstract

Originally considered to be part of a cellular waste pathway, expansive research into exosomes has shown that these vesicles possess a vast array of functional utilities. As vital transporters of materials for communications between cells, particular interest has been generated in the ability of cancer cells to use exosomes to induce immune suppression, and to establish a thriving microenvironment, ideal for disease progression. Exosomes carry and transfer many types of cargo, including microRNAs (miRNAs; miRs), which are important modulators of messenger RNA (mRNA) expression. These miRNAs have been shown to be noteworthy components of the mechanisms used by tumor-derived exosomes to carry out their functions. Alternatively, research has been expanding into using exosomes and miRNAs as both biomarkers for detecting cancer and disease progression, and as potential treatment tools. Here, we discuss some of the progress that researchers have made related to cancer exosomes, their suppression of the immune system and the importance of the miRNAs they shuttle, along with some of the shortcomings, obstacles, and challenges that lie ahead.

https://ift.tt/2sv3yPQ

Innate lymphoid cells—key immune integrators of overall body homeostasis

Abstract

The maintenance of the tissue barrier is essential to protect the host from external pathogens, thus ensuring the survival of the organism. This process requires the integration of various physiological signals originating from the digestive, immune, endocrine, and the nervous system as indicators of overall body fitness. Innate lymphoid cells (ILC) are a group of immune cells equipped for the guarding and maintenance of the tissue barrier against invading pathogens. Extensive research has focused on the regulation of ILC by cytokines derived from immune or non-immune cells, such as the epithelium. However, recent findings suggest that ILC may play an additional role in the monitoring of the overall health status of the host. This requires the combined sensing of cytokines, metabolites, hormones, and neuropeptides. ILC appear to be essential in this process functioning as hubs for the integration of different physiological signals to facilitate barrier immunity. Here, we discuss the emerging literature revealing dietary, metabolic, hormonal, and neuronal signals as important controllers and modulators of ILC function in health and disease.

https://ift.tt/2Hig3TD

Diagnostic utility of FDG-PET in the differential diagnosis between different forms of primary progressive aphasia

Bouwman, F; Orini, S; Gandolfo, F; Altomare, D; Festari, C; Agosta, F; Arbizu, J; ... EANM-EAN Task Force for the Prescription of FDG-PET for Dementin, ; + view all Bouwman, F; Orini, S; Gandolfo, F; Altomare, D; Festari, C; Agosta, F; Arbizu, J; Drzezga, A; Nestor, P; Nobili, F; Walker, Z; Morbelli, S; Boccardi, M; EANM-EAN Task Force for the Prescription of FDG-PET for Dementin, ; - view fewer (2018) Diagnostic utility of FDG-PET in the differential diagnosis between different forms of primary progressive aphasia. European Journal of Nuclear Medicine and Molecular Imaging 10.1007/s00259-018-4034-z . (In press). Green open access

https://ift.tt/2J5KSR0

The biological impact of listening to music in clinical and nonclinical settings: A systematic review

Finn, S; Fancourt, D; (2018) The biological impact of listening to music in clinical and nonclinical settings: A systematic review. In: The Arts and The Brain. Psychology and Physiology Beyond Pleasure. (pp. 173-200). Elsevier B.V.

https://ift.tt/2sDE9mk

Designing a brief behaviour change intervention to reduce sexually transmitted infections: a discrete choice experiment

Miners, A; Llewellyn, C; King, C; Pollard, A; Roy, A; Gilson, R; Rodger, A; ... Shahmanesh, M; + view all Miners, A; Llewellyn, C; King, C; Pollard, A; Roy, A; Gilson, R; Rodger, A; Burns, F; Shahmanesh, M; - view fewer (2018) Designing a brief behaviour change intervention to reduce sexually transmitted infections: a discrete choice experiment. International Journal of STD & AIDS 10.1177/0956462418760425 . (In press). Green open access

https://ift.tt/2J5L9U2

Demonstration of Protein-Based Human Identification Using the Hair Shaft Proteome

Parker, GJ; Leppert, T; Anex, DS; Hilmer, JK; Matsunami, N; Baird, L; Stevens, J; ... Leppert, M; + view all Parker, GJ; Leppert, T; Anex, DS; Hilmer, JK; Matsunami, N; Baird, L; Stevens, J; Parsawar, K; Durbin-Johnson, BP; Rocke, DM; Nelson, C; Fairbanks, DJ; Wilson, AS; Rice, RH; Woodward, SR; Bothner, B; Hart, BR; Leppert, M; - view fewer (2016) Demonstration of Protein-Based Human Identification Using the Hair Shaft Proteome. PLoS One , 11 (9) , Article e0160653. 10.1371/journal.pone.0160653 . Green open access

https://ift.tt/2Hk8uvo

Decellularized Diaphragmatic Muscle Drives a Constructive Angiogenic Response In Vivo

Alvarèz Fallas, ME; Piccoli, M; Franzin, C; Sgrò, A; Dedja, A; Urbani, L; Bertin, E; ... Pozzobon, M; + view all Alvarèz Fallas, ME; Piccoli, M; Franzin, C; Sgrò, A; Dedja, A; Urbani, L; Bertin, E; Trevisan, C; Gamba, P; Burns, AJ; De Coppi, P; Pozzobon, M; - view fewer (2018) Decellularized Diaphragmatic Muscle Drives a Constructive Angiogenic Response In Vivo. International Journal of Molecular Sciences , 19 (5) , Article 1319. 10.3390/ijms19051319 . Green open access

https://ift.tt/2J5KUbA

Cross-talk between human airway epithelial cells and 3T3-J2 feeder cells involves partial activation of human MET by murine HGF

Hynds, RE; Gowers, KHC; Nigro, E; Butler, CR; Bonfanti, P; Giangreco, A; Prele, CM; Hynds, RE; Gowers, KHC; Nigro, E; Butler, CR; Bonfanti, P; Giangreco, A; Prele, CM; Janes, SM; - view fewer (2018) Cross-talk between human airway epithelial cells and 3T3-J2 feeder cells involves partial activation of human MET by murine HGF. PLoS ONE , 13 (5) , Article e0197129. 10.1371/journal.pone.0197129 . Green open access

https://ift.tt/2sEmdbk

Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases

Iglesias, AI; Mishra, A; Vitart, V; Bykhovskaya, Y; Hoehn, R; Springelkamp, H; Cuellar-Partida, G; ... MacGregor, S; + view all Iglesias, AI; Mishra, A; Vitart, V; Bykhovskaya, Y; Hoehn, R; Springelkamp, H; Cuellar-Partida, G; Gharahkhani, P; Bailey, JNC; Willoughby, CE; Li, X; Yazar, S; Nag, A; Khawaja, AP; Polasek, O; Siscovick, D; Mitchell, P; Tham, YC; Haines, JL; Kearns, LS; Hayward, C; Shi, Y; van Leeuwen, EM; Taylor, KD; Bonnemaijer, P; Rotter, JI; Martin, NG; Zeller, T; Mills, RA; Staffieri, SE; Jonas, JB; Schmidtmann, I; Boutin, T; Kang, JH; Lucas, SEM; Wong, TY; Beutel, ME; Wilson, JF; Uitterlinden, AG; Vithana, EN; Foster, PJ; Hysi, PG; Hewitt, AW; Khor, CC; Pasquale, LR; Montgomery, GW; Klaver, CCW; Aung, T; Pfeiffer, N; Mackey, DA; Hammond, CJ; Cheng, C-Y; Craig, JE; Rabinowitz, YS; Wiggs, JL; Burdon, KP; van Duijn, CM; MacGregor, S; - view fewer (2018) Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases. Nature Communications , 9 , Article 1864. 10.1038/s41467-018-03646-6 . Green open access

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Clinical, socioeconomic, and behavioural factors at age 50 years and risk of cardiometabolic multimorbidity and mortality: A cohort study

Singh-Manoux, A; Fayosse, A; Sabia, S; Tabak, A; Shipley, M; Dugravot, A; Kivimäki, M; (2018) Clinical, socioeconomic, and behavioural factors at age 50 years and risk of cardiometabolic multimorbidity and mortality: A cohort study. PLoS Medicine , 15 (5) , Article e1002571. 10.1371/journal.pmed.1002571 . Green open access

https://ift.tt/2sFrH5F

Body composition during early infancy and developmental progression from 1 to 5 years of age: the Infant Anthropometry and Body Composition (iABC) cohort study among Ethiopian children

Abera, M; Tesfaye, M; Admassu, B; Hanlon, C; Ritz, C; Wibaek, R; Michaelsen, KF; ... Kæstel, P; + view all Abera, M; Tesfaye, M; Admassu, B; Hanlon, C; Ritz, C; Wibaek, R; Michaelsen, KF; Friis, H; Wells, JC; Andersen, GS; Girma, T; Kæstel, P; - view fewer (2018) Body composition during early infancy and developmental progression from 1 to 5 years of age: the Infant Anthropometry and Body Composition (iABC) cohort study among Ethiopian children. British Journal of Nutrition , 119 (11) pp. 1263-1273. 10.1017/S000711451800082X . Green open access

https://ift.tt/2kOCtmB