Learning a New Selection Rule in Visual and Frontal Cortex

How do you make a decision if you do not know the rules of the game? Models of sensory decision-making suggest that choices are slow if evidence is weak, but they may only apply if the subject knows the task rules. Here, we asked how the learning of a new rule influences neuronal activity in the visual (area V1) and frontal cortex (area FEF) of monkeys. We devised a new icon-selection task. On each day, the monkeys saw 2 new icons (small pictures) and learned which one was relevant. We rewarded eye movements to a saccade target connected to the relevant icon with a curve. Neurons in visual and frontal cortex coded the monkey's choice, because the representation of the selected curve was enhanced. Learning delayed the neuronal selection signals and we uncovered the cause of this delay in V1, where learning to select the relevant icon caused an early suppression of surrounding image elements. These results demonstrate that the learning of a new rule causes a transition from fast and random decisions to a more considerate strategy that takes additional time and they reveal the contribution of visual and frontal cortex to the learning process.

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Context-Dependent Duration Signals in the Primate Prefrontal Cortex

The activity of some prefrontal (PF) cortex neurons distinguishes short from long time intervals. Here, we examined whether this property reflected a general timing mechanism or one dependent on behavioral context. In one task, monkeys discriminated the relative duration of 2 stimuli; in the other, they discriminated the relative distance of 2 stimuli from a fixed reference point. Both tasks had a pre-cue period (interval 1) and a delay period (interval 2) with no discriminant stimulus. Interval 1 elapsed before the presentation of the first discriminant stimulus, and interval 2 began after that stimulus. Both intervals had durations of either 400 or 800 ms. Most PF neurons distinguished short from long durations in one task or interval, but not in the others. When neurons did signal something about duration for both intervals, they did so in an uncorrelated or weakly correlated manner. These results demonstrate a high degree of context dependency in PF time processing. The PF, therefore, does not appear to signal durations abstractedly, as would be expected of a general temporal encoder, but instead does so in a highly context-dependent manner, both within and between tasks.

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Effects of Hypocretin/Orexin and Major Transmitters of Arousal on Fast Spiking Neurons in Mouse Cortical Layer 6B

Fast spiking (FS) GABAergic neurons are thought to be involved in the generation of high-frequency cortical rhythms during the waking state. We previously showed that cortical layer 6b (L6b) was a specific target for the wake-promoting transmitter, hypocretin/orexin (hcrt/orx). Here, we have investigated whether L6b FS cells were sensitive to hcrt/orx and other transmitters associated with cortical activation. Recordings were thus made from L6b FS cells in either wild-type mice or in transgenic mice in which GFP-positive GABAergic cells are parvalbumin positive. Whereas in a control condition hcrt/orx induced a strong increase in the frequency, but not amplitude, of spontaneous synaptic currents, in the presence of TTX, it had no effect at all on miniature synaptic currents. Hcrt/orx effect was thus presynaptic although not by an action on glutamatergic terminals but rather on neighboring cells. In contrast, noradrenaline and acetylcholine depolarized and excited these cells through a direct postsynaptic action. Neurotensin, which is colocalized in hcrt/orx neurons, also depolarized and excited these cells but the effect was indirect. Morphologically, these cells exhibited basket-like features. These results suggest that hcrt/orx, noradrenaline, acetylcholine, and neurotensin could contribute to high-frequency cortical activity through an action on L6b GABAergic FS cells.

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Regulation of Cortical Dynamic Range by Background Synaptic Noise and Feedforward Inhibition

The cortex encodes a broad range of inputs. This breadth of operation requires sensitivity to weak inputs yet non-saturating responses to strong inputs. If individual pyramidal neurons were to have a narrow dynamic range, as previously claimed, then staggered all-or-none recruitment of those neurons would be necessary for the population to achieve a broad dynamic range. Contrary to this explanation, we show here through dynamic clamp experiments in vitro and computer simulations that pyramidal neurons have a broad dynamic range under the noisy conditions that exist in the intact brain due to background synaptic input. Feedforward inhibition capitalizes on those noise effects to control neuronal gain and thereby regulates the population dynamic range. Importantly, noise allows neurons to be recruited gradually and occludes the staggered recruitment previously attributed to heterogeneous excitation. Feedforward inhibition protects spike timing against the disruptive effects of noise, meaning noise can enable the gain control required for rate coding without compromising the precise spike timing required for temporal coding.

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Timing of Cortico-Muscle Transmission During Active Movement

Numerous studies have reported large disparities between short cortico-muscle conduction latencies and long recorded delays between cortical firing and evoked muscle activity. Using methods such as spike- and stimulus-triggered averaging of electromyographic (EMG) activity, previous studies have shown that the time delay between corticomotoneuronal (CM) cell firing and onset of facilitation of forelimb muscle activity ranges from 6.7 to 9.8 ms, depending on the muscle group tested. In contrast, numerous studies have reported delays of 60–122 ms between cortical cell firing onset and either EMG or movement onset during motor tasks. To further investigate this disparity, we simulated rapid active movement by applying frequency-modulated stimulus trains to M1 cortical sites in a rhesus macaque performing a movement task. This yielded corresponding EMG modulations, the latency of which could be measured relative to the stimulus modulations. The overall mean delay from stimulus frequency modulation to EMG modulation was 11.5 ± 5.6 ms, matching closely the conduction time through the cortico-muscle pathway (12.6 ± 2.0 ms) derived from poststimulus facilitation peaks computed at the same sites. We conclude that, during active movement, the delay between modulated M1 cortical output and its impact on muscle activity approaches the physical cortico-muscle conduction time.

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Cortical Gray and Adjacent White Matter Demonstrate Synchronous Maturation in Very Preterm Infants

Spatial and functional gradients of development have been described for the maturation of cerebral gray and white matter using histological and radiological approaches. We evaluated these patterns in very preterm (VPT) infants using diffusion tensor imaging. Data were obtained from 3 groups: 1) 22 VPT infants without white matter injury (WMI), of whom all had serial MRI studies during the neonatal period, 2) 19 VPT infants with WMI, of whom 3 had serial MRI studies and 3) 12 healthy, term-born infants. Regions of interest were placed in the cortical gray and adjacent white matter in primary motor, primary visual, visual association, and prefrontal regions. From the MRI data at term-equivalent postmenstrual age, differences in mean diffusivity were found in all areas between VPT infants with WMI and the other 2 groups. In contrast, minimal differences in fractional anisotropy were found between the 3 groups. These findings suggest that cortical maturation is delayed in VPT infants with WMI when compared with term control infants and VPT infants without WMI. From the serial MRI data from VPT infants, synchronous development between gray and white matter was evident in all areas and all groups, with maturation in primary motor and sensory regions preceding that of association areas. This finding highlights the regionally varying but locally synchronous nature of the development of cortical gray matter and its adjacent white matter.

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Cortical Dependence of Whisker Responses in Posterior Medial Thalamus In Vivo

Cortical layer 5B (L5B) thick-tufted pyramidal neurons have reliable responses to whisker stimulation in anesthetized rodents. These cells drive a corticothalamic pathway that evokes spikes in thalamic posterior medial nucleus (POm). While a subset of POm has been shown to integrate both cortical L5B and paralemniscal signals, the majority of POm neurons are suggested to receive driving input from L5B only. Here, we test this possibility by investigating the origin of whisker-evoked responses in POm and specifically the contribution of the L5B-POm pathway. We compare L5B spiking with POm spiking and subthreshold responses to whisker deflections in urethane anesthetized mice. We find that a subset of recorded POm neurons shows early (<50 ms) spike responses and early large EPSPs. In these neurons, the early large EPSPs matched L5B input criteria, were blocked by cortical inhibition, and also interacted with spontaneous Up state coupled large EPSPs. This result supports the view of POm subdivisions, one of which receives whisker signals predominantly via L5B neurons.

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Default Mode Network Activity Predicts Early Memory Decline in Healthy Young Adults Aged 18-31

Functional magnetic resonance imaging (fMRI) research conducted in healthy young adults is typically done with the assumption that this sample is largely homogeneous. However, studies from cognitive psychology suggest that long-term memory and attentional control begin to diminish in the third decade of life. Here, 100 participants between the ages of 18 and 31 learned Lithuanian translations of English words in an individual differences study using fMRI. Long-term memory ability was operationalized for each participant by deriving a memory score from 3 convergent measures. Age of participant predicted memory score in this cohort. In addition, degree of deactivation during initial encoding in a set of regions occurring largely in the default mode network (DMN) predicted both age and memory score. The current study demonstrates that early memory decline may partially be accounted for by failure to modulate activity in the DMN.

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Mapping the Dynamic Network Interactions Underpinning Cognition: A cTBS-fMRI Study of the Flexible Adaptive Neural System for Semantics

Higher cognitive function reflects the interaction of a network of multiple brain regions. Previous investigations have plotted out these networks using functional or structural connectivity approaches. While these map the topography of the regions involved, they do not explore the key aspect of this neuroscience principle—namely that the regions interact in a dynamic fashion. Here, we achieved this aim with respect to semantic memory. Although converging evidence implicates the anterior temporal lobes (ATLs), bilaterally, as a crucial component in semantic representation, the underlying neural interplay between the ATLs remains unclear. By combining continuous theta-burst stimulation (cTBS) with functional magnetic resonance imaging (fMRI), we perturbed the left ventrolateral ATL (vATL) and investigated acute changes in neural activity and effective connectivity of the semantic system. cTBS resulted in decreased activity at the target region and compensatory, increased activity at the contralateral vATL. In addition, there were task-specific increases in effective connectivity between the vATLs, reflecting an increased facilitatory intrinsic connectivity from the right to left vATL. Our results suggest that semantic representation is founded on a flexible, adaptive bilateral neural system and reveals an adaptive plasticity-based mechanism that might support functional recovery after unilateral damage in neurological patients.

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Decoding Concrete and Abstract Action Representations During Explicit and Implicit Conceptual Processing

Action understanding requires a many-to-one mapping of perceived input onto abstract representations that generalize across concrete features. It is debated whether such abstract action concepts are encoded in ventral premotor cortex (PMv; motor hypothesis) or, alternatively, are represented in lateral occipitotemporal cortex (LOTC; cognitive hypothesis). We used fMRI-based multivoxel pattern analysis to decode observed actions at concrete and abstract, object-independent levels of representation. Participants observed videos of 2 actions involving 2 different objects, using either an explicit or implicit task with respect to conceptual action processing. We decoded concrete action representations by training and testing a classifier to discriminate between actions within each object category. To identify abstract action representations, we trained the classifier to discriminate actions in one object and tested the classifier on actions performed on the other object, and vice versa. Region-of-interest and searchlight analyses revealed decoding in LOTC at both concrete and abstract levels during both tasks, whereas decoding in PMv was restricted to the concrete level during the explicit task. In right inferior parietal cortex, decoding was significant for the abstract level during the explicit task. Our findings are incompatible with the motor hypothesis, but support the cognitive hypothesis of action understanding.

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Presynaptic Spike Timing-Dependent Long-Term Depression in the Mouse Hippocampus

Spike timing-dependent plasticity (STDP) is a Hebbian learning rule important for synaptic refinement during development and for learning and memory in the adult. Given the importance of the hippocampus in memory, surprisingly little is known about the mechanisms and functions of hippocampal STDP. In the present work, we investigated the requirements for induction of hippocampal spike timing-dependent long-term potentiation (t-LTP) and spike timing-dependent long-term depression (t-LTD) and the mechanisms of these 2 forms of plasticity at CA3-CA1 synapses in young (P12–P18) mouse hippocampus. We found that both t-LTP and t-LTD can be induced at hippocampal CA3-CA1 synapses by pairing presynaptic activity with single postsynaptic action potentials at low stimulation frequency (0.2 Hz). Both t-LTP and t-LTD require NMDA-type glutamate receptors for their induction, but the location and properties of these receptors are different: While t-LTP requires postsynaptic ionotropic NMDA receptor function, t-LTD does not, and whereas t-LTP is blocked by antagonists at GluN2A and GluN2B subunit-containing NMDA receptors, t-LTD is blocked by GluN2C or GluN2D subunit-preferring NMDA receptor antagonists. Both t-LTP and t-LTD require postsynaptic Ca²⁺ for their induction. Induction of t-LTD also requires metabotropic glutamate receptor activation, phospholipase C activation, postsynaptic IP₃ receptor-mediated Ca²⁺ release from internal stores, postsynaptic endocannabinoid (eCB) synthesis, activation of CB1 receptors and astrocytic signaling, possibly via release of the gliotransmitter d-serine. We furthermore found that presynaptic calcineurin is required for t-LTD induction. t-LTD is expressed presynaptically as indicated by fluctuation analysis, paired-pulse ratio, and rate of use-dependent depression of postsynaptic NMDA receptor currents by MK801. The results show that CA3-CA1 synapses display both NMDA receptor-dependent t-LTP and t-LTD during development and identify a presynaptic form of hippocampal t-LTD similar to that previously described at neocortical synapses during development.

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Visual and Haptic Shape Processing in the Human Brain: Unisensory Processing, Multisensory Convergence, and Top-Down Influences

Humans are highly adept at multisensory processing of object shape in both vision and touch. Previous studies have mostly focused on where visually perceived object-shape information can be decoded, with haptic shape processing receiving less attention. Here, we investigate visuo-haptic shape processing in the human brain using multivoxel correlation analyses. Importantly, we use tangible, parametrically defined novel objects as stimuli. Two groups of participants first performed either a visual or haptic similarity-judgment task. The resulting perceptual object-shape spaces were highly similar and matched the physical parameter space. In a subsequent fMRI experiment, objects were first compared within the learned modality and then in the other modality in a one-back task. When correlating neural similarity spaces with perceptual spaces, visually perceived shape was decoded well in the occipital lobe along with the ventral pathway, whereas haptically perceived shape information was mainly found in the parietal lobe, including frontal cortex. Interestingly, ventrolateral occipito-temporal cortex decoded shape in both modalities, highlighting this as an area capable of detailed visuo-haptic shape processing. Finally, we found haptic shape representations in early visual cortex (in the absence of visual input), when participants switched from visual to haptic exploration, suggesting top-down involvement of visual imagery on haptic shape processing.

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Motor Training Promotes Both Synaptic and Intrinsic Plasticity of Layer II/III Pyramidal Neurons in the Primary Motor Cortex

Motor skill training induces structural plasticity at dendritic spines in the primary motor cortex (M1). To further analyze both synaptic and intrinsic plasticity in the layer II/III area of M1, we subjected rats to a rotor rod test and then prepared acute brain slices. Motor skill consistently improved within 2 days of training. Voltage clamp analysis showed significantly higher α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-methyl-d-aspartate (AMPA/NMDA) ratios and miniature EPSC amplitudes in 1-day trained rats compared with untrained rats, suggesting increased postsynaptic AMPA receptors in the early phase of motor learning. Compared with untrained controls, 2-days trained rats showed significantly higher miniature EPSC amplitude and frequency. Paired-pulse analysis further demonstrated lower rates in 2-days trained rats, suggesting increased presynaptic glutamate release during the late phase of learning. One-day trained rats showed decreased miniature IPSC frequency and increased paired-pulse analysis of evoked IPSC, suggesting a transient decrease in presynaptic -aminobutyric acid (GABA) release. Moreover, current clamp analysis revealed lower resting membrane potential, higher spike threshold, and deeper afterhyperpolarization in 1-day trained rats—while 2-days trained rats showed higher membrane potential, suggesting dynamic changes in intrinsic properties. Our present results indicate dynamic changes in glutamatergic, GABAergic, and intrinsic plasticity in M1 layer II/III neurons after the motor training.

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Resting-State Functional Connectivity of the Locus Coeruleus in Humans: In Comparison with the Ventral Tegmental Area/Substantia Nigra Pars Compacta and the Effects of Age

The locus coeruleus (LC) provides the primary noradrenergic inputs to the cerebral cortex. Despite numerous animal studies documenting the functions of the LC, research in humans is hampered by the small volume of this midbrain nucleus. Here, we took advantage of a probabilistic template, explored the cerebral functional connectivity of the LC with resting-state fMRI data of 250 healthy adults, and verified the findings by accounting for physiological noise in another data set. In addition, we contrasted connectivities of the LC and the ventral tegmental area/substantia nigra pars compacta. The results highlighted both shared and distinct connectivity of these 2 midbrain structures, as well as an opposite pattern of connectivity to bilateral amygdala, pulvinar, and right anterior insula. Additionally, LC connectivity to the fronto-parietal cortex and the cerebellum increases with age and connectivity to the visual cortex decreases with age. These findings may facilitate studies of the role of the LC in arousal, saliency responses and cognitive motor control and in the behavioral and cognitive manifestations during healthy and disordered aging. Although the first to demonstrate whole-brain LC connectivity, these findings need to be confirmed with high-resolution imaging.

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Longitudinal Evidence for Smaller Hippocampus Volume as a Vulnerability Factor for Perceived Stress

Hippocampal volume has been found to be smaller in individuals with stress-related disorders, but it remains unclear whether smaller volume is a consequence of stress or rather a vulnerability factor. Here, we examined this issue by relating stress levels to hippocampal volumes in healthy participants examined every 5 years in a longitudinal population-based study. Based on scores of 25- to 60-year–old participants on the perceived stress questionnaire, we defined moderately to high (n = 35) and low (n = 76) stress groups. The groups were re-examined after 5 years (at the 6th study wave). Historical data on subjective stress were available up to 10 years prior to Wave 5. At the first MRI session, the moderately to high stress group had a significantly smaller hippocampal volume, as measured by FreeSurfer (version 5.3), compared with the low-stress group. At follow-up, group differences in stress levels and hippocampal volume remained unchanged. In retrospective analyses of subjective stress, the observed group difference in stress was found to be stable. The long-term stability of group differences in perceived stress and hippocampal volume suggests that a small hippocampal volume may be a vulnerability factor for stress-related disorders.

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Accessing Real-Life Episodic Information from Minutes versus Hours Earlier Modulates Hippocampal and High-Order Cortical Dynamics

It is well known that formation of new episodic memories depends on hippocampus, but in real-life settings (e.g., conversation), hippocampal amnesics can utilize information from several minutes earlier. What neural systems outside hippocampus might support this minutes-long retention? In this study, subjects viewed an audiovisual movie continuously for 25 min; another group viewed the movie in 2 parts separated by a 1-day delay. Understanding Part 2 depended on retrieving information from Part 1, and thus hippocampus was required in the day-delay condition. But is hippocampus equally recruited to access the same information from minutes earlier? We show that accessing memories from a few minutes prior elicited less interaction between hippocampus and default mode network (DMN) cortical regions than accessing day-old memories of identical events, suggesting that recent information was available with less reliance on hippocampal retrieval. Moreover, the 2 groups evinced reliable but distinct DMN activity timecourses, reflecting differences in information carried in these regions when Part 1 was recent versus distant. The timecourses converged after 4 min, suggesting a time frame over which the continuous-viewing group may have relied less on hippocampal retrieval. We propose that cortical default mode regions can intrinsically retain real-life episodic information for several minutes.

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Frequency of Maternal Touch Predicts Resting Activity and Connectivity of the Developing Social Brain

Previous behavioral research points to a positive relationship between maternal touch and early social development. Here, we explored the brain correlates of this relationship. The frequency of maternal touch was recorded for 43 five-year-old children during a 10 min standardized play session. Additionally, all children completed a resting-state functional magnetic resonance imaging session. Investigating the default mode network revealed a positive relation between the frequency of maternal touch and activity in the right posterior superior temporal sulcus (pSTS) extending into the temporo-parietal junction. Using this effect as a seed in a functional connectivity analysis identified a network including extended bilateral regions along the temporal lobe, bilateral frontal cortex, and left insula. Compared with children with low maternal touch, children with high maternal touch showed additional connectivity with the right dorso-medial prefrontal cortex. Together these results support the notion that childhood tactile experiences shape the developing "social brain" with a particular emphasis on a network involved in mentalizing.

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The Suppression of Beta Oscillations in the Primate Supplementary Motor Complex Reflects a Volatile State During the Updating of Action Sequences

The medial motor areas play crucial but flexible roles in the temporal organizations of multiple movements. The beta oscillation of local field potentials is the predominant oscillatory activity in the motor areas, but the manner in which increases and decreases in beta power contribute to updating of multiple action plans is not yet fully understood. In the present study, beta and high-gamma activities in the supplementary motor area (SMA) and pre-SMA of monkeys were analyzed during performance of a bimanual motor sequence task that required updating and maintenance of the memory of action sequences. Beta power was attenuated during early delay periods of updating trials but was increased during maintenance trials, while there was a reciprocal increase in high-gamma power during updating trials. Moreover, transient attenuation of beta power during maintenance trials resulted in the erroneous selection of an action sequence. Therefore, it was concluded that the suppression of beta power during the early delay period reflects volatility of neural representation of the action sequence. This neural representation would be properly updated to the appropriate instructed action sequence via increases in high-gamma power in updating trials whereas it would be erroneously updated without the appropriate updating signal in maintenance trials.

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Similarity-Based Fusion of MEG and fMRI Reveals Spatio-Temporal Dynamics in Human Cortex During Visual Object Recognition

Every human cognitive function, such as visual object recognition, is realized in a complex spatio-temporal activity pattern in the brain. Current brain imaging techniques in isolation cannot resolve the brain's spatio-temporal dynamics, because they provide either high spatial or temporal resolution but not both. To overcome this limitation, we developed an integration approach that uses representational similarities to combine measurements of magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) to yield a spatially and temporally integrated characterization of neuronal activation. Applying this approach to 2 independent MEG–fMRI data sets, we observed that neural activity first emerged in the occipital pole at 50–80 ms, before spreading rapidly and progressively in the anterior direction along the ventral and dorsal visual streams. Further region-of-interest analyses established that dorsal and ventral regions showed MEG–fMRI correspondence in representations later than early visual cortex. Together, these results provide a novel and comprehensive, spatio-temporally resolved view of the rapid neural dynamics during the first few hundred milliseconds of object vision. They further demonstrate the feasibility of spatially unbiased representational similarity-based fusion of MEG and fMRI, promising new insights into how the brain computes complex cognitive functions.

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Insights on methotrexate in psoriatic disease

Publication date: Available online 25 July 2016
Source:Clinical Immunology
Author(s): Jacqueline E. Greb, Ari M. Goldminz, Alice B. Gottlieb
The folic acid analogue methotrexate is used as an anti-neoplastic agent and treatment for inflammatory disorders including psoriasis, dermatomyositis, lupus erythematous, sarcoidosis, and systemic sclerosis. Despite the introduction of newer biologic agents, methotrexate remains a first-line systemic therapy for many patients with disorders of chronic inflammation. Here we briefly describe the current clinical evidence for methotrexate use in psoriatic disease, our current understanding of methotrexate's anti-inflammatory properties, and the future role of methotrexate in the treatment of immune mediated disorders.



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Implications of the diversity of class I HLA associations in psoriatic arthritis

Publication date: Available online 25 July 2016
Source:Clinical Immunology
Author(s): Robert Winchester, Jon Giles, Deepak Jadon, Mohammed Haroon, Neill McHugh, Oliver FitzGerald
We sought to validate and extend the findings of a 282 psoriatic arthritis patient cohort from Dublin using a 219 patient cohort from Bath. The central finding of this study was that several structurally unrelated HLA alleles, including B*08:01:01, B*18:01:01, B*27:05:02, B*55:01:01 and C*06:02:01, were found to be significantly associated with particular phenotypic features of psoriatic arthritis, implying that the clinical diagnosis of psoriatic arthritis designates a genetically heterogeneous subset of individuals. Radiographic sacroiliitis was associated with either B*08:01:01, or B*27:05:02 with implications about the role of MHC molecules in an adaptive immune response. There are implications for psoriatic arthritis diagnostic criteria since some disease features used in the criteria are under genetic control. These findings have important implications for understanding the role of MHC alleles in directing the adaptive immune response to mediate the inflammation responsible for psoriatic arthritis.



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Direct versus sequential immunoglobulin switch in allergy and antiviral responses

Publication date: Available online 25 July 2016
Source:Clinical Immunology
Author(s): E. Svirshchevskaya, G. Fattakhova, S. Khlgatian, D. Chudakov, E. Kashirina, D. Ryazantsev, O. Kotsareva, S. Zavriev
Allergy is characterized by IgE production to innocuous antigens. The question whether the switch to IgE synthesis occurs via direct or sequential pathways is still unresolved. The aim of this work was to analyze the distribution of immunoglobulins (Ig) to house dust mite D. farinae and A. alternata fungus in allergic children with primarily established diagnosis and compare it to Epstein-Barr antiviral (EBV) response in the same patients. In allergy patients the only significant difference was found in allergen specific IgE, likely mediated by a direct isotype switch, while antiviral response was dominated by EBV specific IgG and low level of concordant IgA and IgG4 production consistent with a minor sequential Ig switches. Taken collectively, we concluded that sequential isotype switch is likely to be a much rarer event than a direct one.



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Autoimmunity against laminins

Publication date: Available online 25 July 2016
Source:Clinical Immunology
Author(s): Florina Florea, Manuel Koch, Takashi Hashimoto, Cassian Sitaru
Laminins are ubiquitous constituents of the basement membranes with major architectural and functional role as supported by the fact that absence or mutations of laminins lead to either lethal or severely impairing phenotypes. Besides genetic defects, laminins are involved in a wide range of human diseases including cancer, infections, and inflammatory diseases, as well as autoimmune disorders. A growing body of evidence implicates several laminin chains as autoantigens in blistering skin diseases, collagenoses, vasculitis, or post-infectious autoimmunity. The current paper reviews the existing knowledge on autoimmunity against laminins referring to both experimental and clinical data, and on therapeutic implications of anti-laminin antibodies. Further investigation of relevant laminin epitopes in pathogenic autoimmunity would facilitate the development of appropriate diagnostic tools for thorough characterization of patients' antibody specificities and should decisively contribute to designing more specific therapeutic interventions.



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Recent Advances in the Synthesis of Flavaglines, a Family of Potent Bioactive Natural Compounds Originating from Traditional Chinese Medicine

Flavaglines constitute a distinctive family of plant metabolites isolated from medicinal plants of the genus Aglaia. These compounds exhibit a broad spectrum of distinctive pharmacological properties, including anti-inflammatory, neuroprotective, cardioprotective, and anticancer activities. These natural cyclopenta[b]benzofurans are characterized by densely functionalized tricyclic frameworks, as exemplified by the structures of rocaglamide or silvestrol, which makes them extremely attractive targets for total synthesis, in addition to their therapeutic potential. In this review we describe the various synthetic approaches to the total synthesis of flavaglines, culminating in a new generation of diastereo- and enantioselective total syntheses.

With their fascinating pharmacological profiles and complex molecular architectures, the flavaglines have provided a fertile playing field for synthetic organic chemists. This microreview highlights the achievements in the total synthesis of these complex natural products.

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Synthesis of α-Acyloxynitrones and Reactivity towards Samarium Diiodide

Upon treatment of fructose-derived nitrone 1 with samarium diiodide, with the aim of inducing its umpolung and coupling with electrophiles, an unexpected β-elimination of the benzyloxy group at C-1 was observed, yielding nitrone 2. The mechanism and scope of this transformation were investigated, from nitrone 1 and from five other α-alkoxy or α-acyloxy nitrones. This paper describes the preparation of new nitrones 3 and 4 from d-fructose; their synthesis demonstrates that acyl-protected nitrones can be prepared efficiently by intramolecular N-alkylation of sugar-derived oximes, a strategy previously developed only for ether- or ketal-protected cyclic nitrones. Nitrones 3 and 4 underwent fast β-elimination upon treatment with SmI₂. Contrastingly, no β-elimination occurred with nitrones 5–7, suggesting a specific behavior of endocyclic keto nitrones.

The synthesis of novel acyl-protected d-fructose-derived keto nitrones is described. The latter reacted readily with SmI₂ to regioselectively eliminate one of their α-substituents through formation of an original samarium–enaminolate intermediate. However, the efficiency and selectivity of this process does not extend to non-endocyclic α-heterosubstituted nitrones.

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Expeditious Synthesis of Isoquinolones and Isocoumarins with a Vinyl Borane as an Acetylene Equivalent

An innovative and simple expeditious synthesis of 3,4-unsubstituted isoquinolones and isocoumarins starting from a safe and easy-to-handle two-carbon acetylene equivalent was developed. The synthetic potential of this new method was further demonstrated in the facile total synthesis of two naturally occurring alkaloids, corydaldine and doryanine.

An innovative and simple two-step high yielding synthesis of isoquinolones and isocoumarins starting from safe and easy-to-handle substrates is reported. The synthetic potential of this method was further demonstrated in the facile three steps and high yielding total synthesis of two naturally occurring alkaloids, corydaldine and doryanine.

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Borosilicate Activation of (Difluoroiodo)toluene in the gem-Difluorination of Phenyldiazoacetate Derivatives

A combined experimental and computational investigation was conducted to identify a mild and effective Lewis-acidic activator for TolIF₂ in the gem-difluorination of diazo compounds. Computationally, borosilicate, a common constituent of laboratory glassware, was found to spontaneously activate TolIF₂, and an extensive experimental survey confirmed borosilicate as the most effective activator to date. The key to realizing this borosilicate-activated reaction was the use of high purity TolIF₂, which is prepared by a reproducible, multigram-scale synthesis.

A computational and experimental search for mild Lewis-acidic activators for (difluoroiodo)toluene (TolIF₂) has identified borosilicate glass as the most effective activator (to date) in the gem-difluorination of phenyl diazoacetate derivatives.

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Cryptochirality in 2,2′-Coupled BODIPY DYEmers

The two chromophores in 2,2′-coupled BODIPY DYEmers are linearly arranged and possess a configurationally stable axis. Their successful enantiomeric resolution was shown by HPLC-UV and HPLC–ECD on-line measurements. In accordance with theoretical predictions, the main UV/Vis signal of the dimers is redshifted in comparison with that of the monomers, and no exciton couplets are observed in the electronic circular dichroism (ECD) spectra. Moreover, the experimental ECD spectra have a very low intensity over the wavelength region from 300 to 800 nm and the linear BODIPY DYEmers thus show cryptochirality. The reason for this phenomenon is the peculiar molecular arrangement together with the conformational behavior of the dimers. For each compound two different conformations are possible around the biaryl axis that exhibit nearly mirror-image ECD spectra. As a result, the overall ECD curves show only weak signals dominated by vibronic coupling effects. Thus, the method commonly used to determine absolute configurations by TDDFT calculations is not reliable for linear BODIPY dimers and only VCD investigations (experimental in combination with DFT calculations) could unambiguously determine the absolute configurations of the 2,2′-coupled BODIPY DYEmers.

Much too linear. 2,2′-Coupled BODIPY DYEmers are nearly ECD-silent due to the linear alignment of their main transition dipole moments and to the high conformational flexibility at the axis. Only VCD investigations are suitable for elucidating the absolute configurations of these compounds by chiroptical methods in combination with DFT/TDDFT calculations.

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Correction: Beyond "turn-on" readout: from zero background to signal amplification by combination of magnetic separation and plasmon enhanced fluorescence

Chem. Commun., 2016, Advance Article
DOI: 10.1039/C6CC90336C, Correction

Open Access

  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.

Suqin Gong, Yunsheng Xia
To cite this article before page numbers are assigned, use the DOI form of citation above.
The content of this RSS Feed (c) The Royal Society of Chemistry

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Biobased Polyamides: Recent Advances in Basic and Applied Research

Polyamides represent a very important class of polymers for a wide range of applications. After establishing in the 1930s with Nylon and Perlon, their impact on many branches has been continuously growing. In the context of developing sustainable polymers from renewable resources, many polyamides have meanwhile been described, which are based on natural building blocks. In addition to their sustainability, these biobased starting materials can provide special structural features to the resulting polymers and their properties, e.g., side groups, functionalities, or stereoinformation. While some biopolyamides are known for decades and well established (e.g., PA-11, Rilsan), many other promising candidates have been described in fundamental research studies, which have high potential but whose capability—especially for large scale and/or high-performance materials—will have to be proved in the future. Other candidates are very interesting from a scientific point of view, but with less potential for a market establishment due to price and/or feasibility reasons. This article aims at collating the recent developments in the field of biopolyamides and elucidating their properties and potential for different applications.

In the context of sustainable polymers, many synthetic routes to biobased polyamides are described with a focus on recent developments, and the applications are discussed. It is shown that polycondensation of renewable dicarboxylic acids and diamines as well as ring-opening polymerization of biobased, structurally interesting lactams afford a large variety of different polyamides with different properties for many applications.

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On a New Class of -Valent Meromorphic Functions Defined in Conic Domains

We define a new class of multivalent meromorphic functions using the generalised hypergeometric function. We derived this class related to conic domain. It is also shown that this new class of functions, under certain conditions, becomes a class of starlike functions. Some results on inclusion and closure properties are also derived.

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Chemical Composition and Antimicrobial Potential of Palm Leaf Extracts from Babaçu (Attalea speciosa), Buriti (Mauritia flexuosa), and Macaúba (Acrocomia aculeata)

Babaçu (A. speciosa), Buriti (M. flexuosa), and Macaúba (A. aculeata) are palm trees typical of the ecotone area between Cerrado and the Amazon rainforest. The purpose of this study was to evaluate the antimicrobial potential of the extracts prepared from the leaves of those palms as well as determine their chemical compositions. The ethanol extracts were prepared in a Soxhlet apparatus and tested by disk diffusion and agar dilution technique against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Candida parapsilosis. However, there was no significant activity at concentrations of 25, 50, and 100 mg·Ml−1. Moreover, the phytochemical analysis revealed the presence of tannins, flavonoids, catechins, steroids, triterpenes, and saponins. Gas chromatography (GC/MS) analysis also identified organic acids, such as capric (decanoic) acid, lauric (dodecanoic) acid, myristic (tetradecanoic) acid, phthalic (1,2-benzenedicarboxylic) acid, palmitic (hexadecanoic) acid, stearic (octadecanoic) acid, linoleic (9,12-octadecadienoic) acid (omega-6), linolenic (octadecatrienoic) acid (omega-3), and the terpenes citronellol and phytol. Based on the chemical composition in the palm leaf extracts, the palms have the potential to be useful in the food, cosmetic, and pharmaceutical industries.

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Microscopic Fluid Dynamic Simulation of the Metal Foam Using Idealized Cell Structure

Abstract

Simple, yet accurate representation of cell structure is essential when conducting a multidimensional thermo-fluid simulation on porous medium in microscopic scale. Presented in this paper is a study of the fluid dynamic simulation of the nickel metal foam's unit cell domain using idealized cell structure. Commercially available multi-physics package, COMSOL, was utilized to conduct numerical simulation. Simplified methodology to create an idealized cell structure of metal foam is presented, and simulation results on pressure drop are discussed. Nonlinear solver in COMSOL was utilized to solve the unidirectional pressure drop and permeability across the cell structure. Obtained results showed confirmed agreement to the data obtained from the experiment and previous researchers, verifying the practicality and applicability of the proposed unit cell structure.

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A study of variations in the branching pattern of popliteal artery and its clinical perspective

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Anisha Bettaiah, Sangeetha Venkat, Saraswathi G..
Background: Popliteal artery is the continuation of femoral artery which is the main and prime arterial supply to the knee, leg and foot. Variations of popliteal artery have been the subject of repeated study as exposure of this artery is required in both emergency and elective vascular procedures. Knowledge of the anatomical variations in the branching of popliteal artery is important, because damage to artery and its branches can lead to limb disability or life threatening haemorrhage. Methods: A total of 40 popliteal arteries were studied by dissection method. Specimens were collected from the cadavers which were available in the department of anatomy, JSS medical college, Mysore, India. Results: The origin, course and termination of the popliteal artery in all the 40 specimens were normal. Regarding the branching pattern of genicular arteries, there was a common stem of origin for superior medial genicular artery (SMGA), middle genicular artery (MGA), superior lateral genicular artery (SLGA) in 2 specimens (5%). Conclusions: Popliteal artery is the commonly approached site for above and below knee bypass grafts. It is also frequently injured during penetrating and blunt trauma involving lower extremity. Although prevalence of the variations was less in our study, the awareness of possible variations will be beneficial to angiographers and to vascular surgeons and orthopaedic surgeons.


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Role of triple phase computed tomography findings for evaluation of hepatic lesions

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Chandra Prakash Ahirwar, Abhijit Patil, Neelam Soni.
Background: Liver is prone to various diseases including benign and malignant because of its major function of digestion, detoxification and rich blood supply by hepatic artery and portal vein. Objectives of the study were to study the characteristic features of various hepatic lesions using triple phase CT as diagnostic modality, differentiating benign hepatic lesions from malignant and correlating findings of triple phase CT with clinical, histopathology or post-operative findings for calculation of its efficacy. Methods: A total of 100 patients were enrolled in this cross-sectional study done in Department of Radiodiagnosis, Gandhi Medical College, Bhopal, Madhya Pradesh, India. All patients underwent triple phase CECT examination and its accuracy, sensitivity and specificity was calculated. Results: Triple phase CT be excellent diagnostic modality for characterisation and better evaluation of hepatic masses with sensitivity of 91.3% , specificity 97.8% , PPV 91.3% and NPV 97.8% (p value


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Metacognitive awareness- evaluation and implications in medical students

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Pallavi Panchu, Biju Bahuleyan, Seethalakshmi K, Tom Thomas.
Background: Medical education is at cross roads today with a mismatch between students expectations of their performance and the reality. This led us to explore the reason for the academic decline. During our search, we found that metacognitive awareness plays a key role in moulding the learning skills of adult learners. Hence this study was conducted to evaluate the metacognitive awareness of medical students studying in the first year of MBBS. Methods: 100 first year medical students were included in the study and metacognitive awareness inventory questionnaire, a validated tool was administered to the students. This measures metacognitive knowledge and regulation. The results were obtained, tabulated and analysed. Results: Metacognitive awareness among medical students was average. Metacognitive knowledge was found to be significantly better than regulation. On comparing the genders, we note that females have better metacognitive regulation while males score higher in metacognitive knowledge which was statistically significant. Conclusions: The findings of the present study points towards the need of introduction of metacognitive strategies in the medical curriculum with more emphasis on problem based learning in order to make our learners become independent thinkers and efficient care givers.


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Exploring nutritional status, physical activity and body mass index of Pakistani teens

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Kiran Khan, Nazia Jameel, Rehana Khalil, Saadia Gul.
Background: Obesity is becoming an increasingly prevalent problem in Pakistan, as it has in other developing countries. Childhood obesity poses high cost to the well-being and negatively affects childrens health, causes chronic disease as children grow older. The aim of this study was to explore nutritional status, physical activity and body mass index (BMI) of school and college going students of mid and late adolescence age (14 to 19 years) studying in multi-ethnic city of Karachi, Pakistan. Methods: A descriptive cross-sectional study was carried out among school and college going students of public and private educational institutes of Karachi, Pakistan. The study sample of 171 students was conveniently selected from these institutes. The data was collected through a semi-structured questionnaire. In order to calculate BMI, the height and weight of each student were measured after completion of the questionnaire. The data were entered and analysed using IBM SPSS version for Windows 20.0 software. Results: The average age of the respondents was 16.2 years with 68% students belonged to school and 32% to College, and 57.3% were males and 42.7% were females. More than half sample (59.6%) participants belonged to privileged and 40.4% to underprivileged class. The sample was eating a wide variety of junk food in daily routine including chips, packed fruit juices, packed flavoured milk, ice creams/ frozen yogurts both at home and at school/college. The physical activity of the school students was found to be better than the college students. No participant had regular activity or strenuous physical games for more than one hour per day. Around one third (38%) respondents used to watch TV or play computer games for more than two hours a day. Almost half of the students BMI was within the normal ranges, but remaining half of the sample was either overweight or underweight. Conclusions: This study indicates that a large proportion of school and college students had physical inactivity, unhealthy dietary habits and they were overweight. All these interrelated factors were independent of their household socioeconomic condition and ethnicity. There is a need to educate and create awareness about healthy lifestyle among the adolescents and the community at large.


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Difficult patients from the perspective of healthcare workers: a study at a public hospital

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Selahattin Akyüz, Erhan Biyik, Pınar Yalçin-Balçik.
Background: The purpose of the study is to identify the frequency of encounters with difficult patients, the level of patient difficulty and the demographic characteristics of difficult patients from the perception of healthcare workers. Methods: The data have been obtained from the health workers who are employed at a public hospital in the city of Ankara and are in interaction with patients. The data have been obtained with the difficult patient and healthcare personnel interaction survey. Results: It has been determined that approximately 2 out of every 10 patients (=2.11) which the healthcare workers encounter during the day are difficult patients and the level of difficulty of these patients is low (=3.62). It has been found that there is a medium level, positive and significant relationship between patient difficulty and seductive behavior and that seductive behavior has a significant effect on patient difficulty. It has been found that there is a medium level, positive and significant relationship between the discomfort experienced by the personnel and seductive behavior and that seductive behavior has a significant effect on the discomfort experienced by the personnel. Conclusions: As a result, it can be seen that nearly a fifth of all patients are perceived as difficult by healthcare workers. It is believed that healthcare workers should be informed about the characteristics of difficult patients and the aspects which should be taken into consideration while interacting with these patients and thereby more effective form of communication will be established at medical institutions.


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Outcome of albendazole therapy in the management of hepatic hydatid disease

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Shams Ul Bari, Mohd Mubarik Naqash, Ajaz A. Malik.
Background: The treatment modalities for managing patients with hepatic hydatidosis include surgical treatment and non-surgical treatments. The non-surgical methods include albendazole therapy and percutaneous management. Use of albendazole as an adjuvant therapy to surgery has been found to significantly reduce the viability of daughter cyst and recurrence of hydatid disease. The aim of the study was to understand the effect of albendazole therapy on the viability of protoscoleces and recurrence rate of hydatid disease of liver. Methods: The study was conducted at Sher-i-Kashmir Institute of Medical Sciences and Medical College, Srinagar, Kashmir India, from March 2010 to February 2012 with further follow up of 3-4 years and the total of 64 patients were studied. ; Patients were divided into two groups, Group A and Group B, each comprising of 32 patients. In group A, patients were given albendazole for 12 weeks preoperatively followed by further postoperative course for 12 weeks. In group B, patients were first taken for surgery followed by postoperative course of albendazole for 12 weeks. The two main outcome measures studied and compared during present study were the viability of the hydatid cysts and the recurrence rate in two groups. Results: Out of those, patients who received preoperative albendazole, 9.37% had viable cysts at the time of surgery as compared to 96.87% of patients who did not receive any preoperative albendazole. In those patients who received only postoperative albendazole therapy, recurrence rate was 18.75% while as there was no recurrence was in patients who received both preoperative and postoperative albendazole therapy. Conclusions: Study concludes that albendazole is safe and effective adjuvant therapy in the treatment of hydatid liver disease.


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Etiological study of generalized lymphadenopathy in a tertiary care hospital

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Subrata Halder, Bikram Kr. Saha, Debasis Sarkar, Srabani Ghosh.
Background: This study was done to know about the clinical biochemical as well as radiological profile of patients presented as generalized lymphadenopathy in a tertiary care centre and to know the different causes of generalized lymphadenopathy. Methods: 116 patients of generalized lymphadenopathy were included this study based on the inclusion and exclusion criteria. Detailed history, physical examination and relevant systemic examination including detailed examination of lympho-reticular system were done as per a structured proforma and necessary lab investigations were done for confirming diagnosis. Results: Among 116 patients of generalized lymphadenopathy 59.5% were non-malignant causes where 40.5% diagnosed as malignant causes. Among them tuberculosis consist of 39 (33.6%), NHL 18 (15.5%), reactive lymphadenopathy 16 (13.8%), CLL and HD 8 (6.9%) each, ALL 7 (6%), SLE 5(4.3%), Kikuchis disease 4 (3.4%), AML and RA 3 (2.6%) each and castlemans disease, phenytoin lymphadenopathy, metastatic lung and breast carcinoma 1 (0.9%) each. Cervical groups of lymph nodes were most commonly involved 86 patients (74.1%) followed by axillary groups 73 patients (62.9%). Lymph nodes size 1.5cm were due to malignant and non-malignant granulomatous cases. FNAC give definite diagnosis 80.9% malignant cases where 76.8% in non-malignant cases. HPE shown definite diagnosis in 100% cases both malignant and non-malignant diseases. Conclusions: Tuberculosis is most common cause of generalized lymphadenopathy followed by lymphoma. And reactive lymphadenitis is also an important consideration.


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Knowledge, attitude and practices towards consumption of caffeine containing drinks among the student population of Ras al-Khaimah medical and health sciences university, UAE

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Vijayalakshmi S. Bhojaraja, Harshitha Janardhan, Najila Abdul Hameed, Fahmidha Gulsoom A. R., Maryam Zulfiqar Ali.
Background: Caffeine, worlds most widely consumed and legally accepted psychoactive substance which is commonly found ingredient in many drinks like coffee, tea, carbonated drinks and energy drinks. The objective was to explore how much dependent are the teenagers and young adults on caffeine containing drinks, reasons and circumstances for the consumption and to know the knowledge and attitude of the consumers about the health effects of the caffeine containing drinks. Methods: A validated questionnaire was administered randomly to about 298 students from MBBS, BDS, B Pharma and Nursing programmes of RAK Medical and Health Sciences University (RAKMHSU). Results: Out of 298 students in the study, 97% (n=290) of them drink caffeinated beverages in the form of coffee (53%), tea (43%), energy drinks (17%), carbonated drinks (18%) and all of the above (11%). The major reasons for consuming varied, where more than half of them gave the reason as to keep them awake for study purpose (53%), to get refreshed (51%), taste and flavour (49%). About 56% were of an opinion that they do experience different symptoms if they dont consume their daily caffeine intake. 54% students admitted their caffeine consumption has been increased after joining the university. When knowledge and attitude were questioned, 63% of them think caffeine addiction is a health issue and majority of them were aware of the ingredients of these drinks but not the safest amount. Conclusions: Drinking caffeine containing drinks by the students are variable from different sources, so monitoring is necessary for the daily intake and there is need for educational programmes about the health effects related to high consumption of caffeine.


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Cognitive function and its association with level of education and work status in adults in Saudi Arabia: a cross-sectional study

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Mohammed Alarabi, Abdullah Al-Turki, Mohammed Mahasin, Abdulrahman Al-Sehly, Faisal Al-Dawood, Saleh Al-Kurini, Shahid Bashir.
Background: Cognitive decline is not inevitable with age; studies have shown that it can be affected by a number of education and work related factors. We explored this association by carrying out a cross-sectional study in King Khalid University Hospital and King Abdulaziz University Hospital in Riyadh, Saudi Arabia. Methods: We enrolled 202 adults, whose ages ranged between 40 and 85 years. Data was collected using a validated Arabic translation of a standardized test assessing cognitive function, known as the Mini Mental State Examination (MMSE). Subjects were also inquired about their level of education and work status. Results: The results showed that in our subjects of adults above the age of 40, the mean MMSE score was 23.45 (SD=4.203). Females (n=94) had lower scores than their male counterparts (n=108) (mean difference: 3.11, 95% CI 2 to 4.22; p


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Prevalence of oral mucosal lesions and associated habits in Kashmir, India

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Tasneem S. Ain, Owais Gowhar, Saima Sultan, Pradeep Tangade.
Background: A large number of factors may influence the conditions of oral-mucosa and regulate its thresholds against reactions to external irritations and insults. External damage to the tissues may be caused by infections and or other chemical, thermal and mechanical means or there may be some genetic factors involved. The aim of the study was to determine the prevalence of different oral habits and habit related oral lesions among the study population in Kashmir, India. Methods: The final study sample comprised of 7000 patients visiting 2 Government Hospitals in Srinagar and Pulwama district, Kashmir, India. All the selected subjects were examined for any oral mucosal lesions. The diagnosis of the lesion was made based on history, clinical features, according to standard guidelines and color atlas. Results: Prevalence of oral mucosal lesions was found to be 8%. Smokers palate was the most frequently found oral lesion comprising of 33.89% followed by oral lichen planus and leukoplakia (13.55% each). Other lesions included chemical burns, erythroplakia, OSMF and lichenoid reactions. Subjects were indulged into various habits; the most prevalent being the cigarette smoking (56.46%), followed by hukka and bidi smoking and smokeless tobacco. Conclusions: The prevalence of oral mucosal lesions was 8% among the study sample. Subjects were associated with various deleterious habits which were found more in males than females. This study helps in public awareness about the ill effects of oral habits and may motivate them in overcoming their indulgence.


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Retrospective study on predictive scoring system for amputation in open fracture of tibia type III

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Made Bramantya Karna.
Background: Mangled leg remains a challenge in the surgical treatment. Mangled extremity severity score (MESS) is often used as a predictive scoring system. However MESS considered less sensitive because there are still many patients facing amputation legs should be maintained in the end. For that reason, it is necessary to evaluate the counting system has been used. Methods: The study design was a retrospective study using medical records of patients with open fractures of the tibia grade III in emergency room of Dr. Soetomo hospital. From the data on patient medical records, MESI, PSI, HFS, LSI, MESS and NISSSA was calculated. Then the results are assessed by sensitivity, specificity, PPV and NPV. Results: Patients who undergo amputation were 12 people and who successfully maintained limb were 46 people. The sensitivity ranged from 50% (MESI) until 75% (HFS), a specificity ranging from 61% (HFS) until 85% (NISSA). Positive predictive value ranged between 23% (PSI) and 53% (NISSA) and negative predictive value ranged from 81% (PSI) until 91% (NISSA). Conclusions: This study failed to demonstrate the usefulness of the six counting system because it only shows the sensitivity and specificity in distinguishing limb amputation injuries that require immediate and that allows it to be maintained. Some have incorrectly predicted the counting system, where some patients were successfully maintained limb had been predicted for amputees and vice versa.


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Eating disorders and anxiety among high school students in Western area of Turkey

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Egemen Unal, Resat Aydin, Mehmet Enes Gokler, Alaettin Unsal.
Background Eating disorders (ED) are the one of the most common chronic illness among adolescents. The aim of the present study was to investigate eating disorders and it's associations between anxiety among high school students in Sivrihisar in Eskisehir, Turkey. Methods: This cross-sectional study was carried out in the high school students of center of Sivrihisar between 01 January 2014 and 28 February 2014. The questionnaire prepared according to literature, consisting of 3 parts (socio-demographic characteristics, eating attitude test (EAT-40) and beck anxiety inventory (BAI)). The students completed questionnaire in the presence of a member of the research team. The data collected were self-reported by the students. Results: Of the study group 64.4% (n=625) were females and 35.6% (n=345) were males. The prevalence of eating disorder was 13.0% (n=126). The mean and standard deviation of students' total score of EAT-40 were 18.80±9.88 (ranged 3 to 95). The mean and standard deviation of students' total score of BAI were 20.32±12.32 (ranged 0 to 63). The positive weak correlation was found between the total scores of EAT-40 and BAI (r=0.178; p=0.001). Conclusions: ED is an important health problem for adolescents. On the studies upon epidemiology of ED towards high school students, socio-economic factors should be assessed in more detailed and more comprehensive perspective.


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Pediatric urolithiasis: What role does metabolic evaluation has to play?

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Sonia Bhatt, Nalini Bhaskaranand, Dilip Kumar Mishra.
Background Pediatric urolithiasis is a perplexing problem faced by pediatricians as well as urologists across the globe. By early diagnosis and treatment of these risk factors, future stone formation may be prevented. Aim: To evaluate the clinical, biochemical and metabolic characteristics of the patients and the interventions required to prevent recurrence. Methods: In this retrospective study, cohort of pediatric patients presenting with urolithiasis at Kasturba Medical College, Manipal formed the study population. Patients records served as study tools. Medical records department was approached and data was collected. Metabolic evaluation was done in all children. Urine tests included urinalysis, urine culture, 24 hours urinary pH, volume, calcium, oxalate, citrate, uric acid, and creatinine. Finally a total of 58 pediatric urolithiasis cases were included in this study. Results: Mean age of study subjects was 6.85±1.27 years. Top three presentations of pediatric urolithiasis were symptoms of Urinary tract infection (UTI), abdominal pain and flank pain in 29.3%, 24.1% and 17.2% children respectively. Gross hematuria was observed in 15.5% of cases. 82.6% of stones were renal stones. Calcium oxalate stone was most common (50%) variety found. Hyperoxaluria was the most common (79.3%) metabolic abnormality detected. 31% had stone recurrence during follow up and 8 of these had >1 metabolic abnormality. Only 6/28 (21.4%) patients managed conservatively had stone recurrence whereas 12/30 (40%) managed with a procedure had stone recurrence. Conclusions: Metabolic evaluation for urolithiasis helps us to identify children those at increased risk for recurrent stone disease. Thus metabolic evaluation is a must in all pediatric patients as it helps in segregating patients needing medical therapy.


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Importance of yoga in diabetes and dyslipidemia

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Riyaz Mohammed, Asiya Banu, Imran S., Rajiv Kumar Jaiswal.
Background: The present study was aimed at studying the effect of practicing yoga in patients with type 2 DM for 4 months. The practice of yoga in these patients resulted in a decrease in body weight, total cholesterol, triglycerides and LDL cholesterol and an increase in HDL. Yoga based programs are a low-cost intervention strategy to improve physical and psychological well-being. Rhythmic extension and bending in yoga provides stimulation to organs and glands without straining the muscles. Yoga could be also useful in patient suffering from insulin resistance syndrome. Methods: 50 patients with known type 2 diabetes mellitus and dyslipidemia were selected for the study. Known diabetic patients on treatment with sulphonylurea were also included in this study. 50 patients with type 2 DM attending the diabetic clinic were randomized into control group and study group of 25 patients each. The study group was on oral hypoglycemic drugs, lifestyle modification and yoga for a period of 4 months. The control group was prescribed oral hypoglycemic drugs only and did not perform yogic exercises during this period. Results: 4 months of study has shown that patient enrolled in study group had mild decrease in BMI, and body weight which was not statistically significant but there was a significant reduction in total cholesterol, triglycerides and LDL cholesterol, apart from it, there was a non-significant elevation in HDL. Control group showed a significant increase in body weight. It was also noted that there was non-significant increase in total cholesterol, triglycerides and a decrease in HDL. The bodyweight increase could be attributed to drugs like Sulphonylurea also. Conclusions: Yoga has been tried for its benefit not only in India bur also in developed countries. In view of the benefits of yoga therapy in short-term studies and long-term studies, more awareness and emphasis should be given for it. Patient should be explained clearly about the beneficial effects of yoga. Yoga can help in improved lipid profiles, lower BMI, and lowers glycemic levels which can have a long term beneficial effect on Micro and macro-vascular complications in diabetes.


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An analysis of ear discharge and antimicrobial sensitivity to the bacteria used in its treatment

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Mukund M. Vaghela, Hiren Doshi, Sneha Rajput.
Background: Children are unique population with distinct development and physiological differences from adults, clinical trials in children are essential to develop age-specific, empirically verified therapies and interventions to determine and improve the best medical treatment available. The aim of this study was to find out the appropriateness and accuracy of the dose of drugs prescribed and compares it with standard dose. Methods: Total 400 prescriptions were collected from the OPD of the paediatrics of Shree Krishna Hospital, Karamsad. Calculation of standard total daily dose for each drug was done by using Clarks formula and was compared with that of prescribed dose of that particular drug. Results: Total 1042 drugs were prescribed. Among antibiotics (22%) statistically significant difference in the prescribed and standard total daily dose was observed with cefexime [t-value 28.6>1.96 for 95% confidence interval] and metronidazole [t-value2.03>1.96 for 95% confidence interval], NSAIDs (31%), Paracetamol [t-value11.14>1.96 for 95% confidence interval] and antihistaminics (22%), phenylephrine [t-value7.1>1.96 for 95% confidence interval], cetrizine [t-value2.4>2.00 for 95% confidence interval]. Conclusions: Results show that prescribed doses of commonly used drugs were higher than the standard dose. This is directly related to the occurrence and severity of adverse drug reactions.


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A study on relationship of facebook and game addictive behaviour with personality traits among medical students

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Vijay Kumar Saini, Girish Chandra Baniya, K. K. Verma, Aditya Soni, Santosh Kumar Kesharwani.
Background: Use of social networking sites and playing internet games are more common web activities among adolescents. Students are more prone to internet abuse for several reasons- natural affinity towards internet, free and unlimited access, flexible schedules, and freedom from parental interference and psychological immaturity. The aim was to study on relationship of facebook and game addictive behaviour with personality characteristics among medical students. Methods: This was a cross sectional observational study, carried out on 140 medical students. All the students were taken randomly. Assessment of sociodemographic details was done with the help of semi-structured performa, bergen facebook addiction scale, game addiction scale and big five inventory were used to see facebook and game addictive behavior and personality traits. Statistical analysis used for comparison of dichotomous variables chi-square test. Correlation and Linear regression was applied to see association. Data analysis was done with the help of statistical software SPSS 23. 0. Results: Mean score of facebook addiction scale among medical students was 39.94 (S.D. 13.133) and mean score of Game addiction scale was 11.19 (S.D. 04.966). It was found that agreeableness (β= -0.275, p=0.000) and extraversion (β = -0.368, p = 0.000) displayed significant associations with FB Total. While neuroticism (β=0.277, p=0.001) and agreeableness (β= -0.177, p=0.029) displayed significant associations with game addictive behavior. Conclusions: In our study we conclude that students with high agreeableness, high neuroticism and low extraversion were more related with Facebook and game addictive behavior. Extraversion was the most powerful predictor of Facebook addiction and neuroticism for gaming addiction.


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Percutaneous nephrostomy or double J stenting, which is better modality for obstructive uropathy-a descriptive study

2016-07-26T04-37-20Z
Source: International Journal of Research in Medical Sciences
Vinamra Mittal, Manoj Biswas, Shobha Lal.
Background: Percutaneous Nephrostomy or Ureteric Stenting is indicated in patients with Acute Renal Failure following urinary tract obstruction. The purpose of this study was to evaluate the better treatment modality in terms of S. Creatinine level. Methods: Total 50 patients with Creatinine level of >2 mg/dl and hydronephrosis due to upper urinary tract obstruction were grouped into either percutaneous nephrostomy or stent insertion groups. These patients were then evaluated by overall trend of S. creatinine and urine output levels postoperatively. Results: Two comparable groups of PCN and DJS were formed with a mean age of 45.5 years and 47.9 years. Male to female ratio was 1.5:1 and 1.2:1 respectively. Pain with oliguria or anuria was the major presentation. The urine output levels showed a sudden increase postoperatively with a subsequent trend towards normal value in both the groups. Creatinine however showed a normalizing trend from a mean 6.46 mg/dl preoperatively to 1.01mg/dl postoperatively in PCN group whereas in DJS group 5.38mg/dl preoperatively to 2.75mg/dl with a rising trend from POD 15 requiring conversion to PCN in 20% of patients with subsequent normalization of creatinine levels to 0.95 mg/dl. Statistically we found no difference in the outcome when both the groups were compared in view of serum creatinine and urine output levels whereas there is a significant difference in the pre and post operative outcome of both the groups. Conclusions: Our results thus support that though there is no significant difference among both the procedures, ureteral stents are associated with intolerable lower urinary tract symptoms owing to conversion to secondary percutaneous Nephrostomy. Hence percutaneous nephrostomy is superior to ureteral stents for diversion of urine in patients with ARF due to obstructive uropathy.


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