Ossifying fibroma mimiking jaw tumour: A radiographic dilema

Fibro-osseous lesions (FOLs) of the craniomaxillofacial region comprise a group of developmental, dysplastic, and neoplastic alterations. FOLs include ossifying fibromas (OF), cemento-ossifying fibroma (COF), familial gigantiform cementoma (FGC), fibrous dysplasia (FD), and cemento-osseous dysplasia (COD). Evidence suggests that some FOL, especially FD and OF may have a risk of spontaneous malignant transformation. This report documents a rare case of malignant transformation of ossifying fibromas of the jaw and the probable cause for same. Although it is rare, the clinician should have a complete follow up to observe such changes among the patients having FOLs.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Retroperitoneal Cyst of Mullerian Type

Retroperitoneal mullerian cysts are rare, benign neoplastic cyst of urogenital subtype. They are usually asymptomatic and may present with symptoms if they grow considerably in size with pressure over the adjacent organ or follow infection, hemorrhage or rupture. Histologically, these cyst are lined with benign ciliated columnar epithelium. We present the case of a 30-year-old female with history of abdominal distension and epigastric pain. The mass excised was in retroperitoneal space and microscopic examination revealed benign cyst of mullerian origin.

Prevalence and Predictors of Depression, Anxiety and Stress among Elderly during COVID-19: A Cross-sectional Study from Central India

During the COVID-19 pandemic, elderly people have been more prone to depression, anxiety and stress. During these trying times, they require more attention and support for their mental health. This cross-sectional study was performed with the duration of 06 months from March 2021 to August 2021 in AIIMS, Bhopal in the state of Madhya Pradesh, in central India. And the participants recruited by systematic random sampling from a population aged more than 60 years, those who were able to read and write Hindi or English and having at least one family member; who reported to AIIMS, Bhopal during the second wave of COVID-19 in India. Those who were confirmed COVID-19 cases and undergoing treatment for the same, with diagnosed mental health disorders and who didn't give consent were excluded. A Google form based online semi-structured questionnaire along with DASS-21 scale was completed by participants. Elderly (>=60 years) will be selected. Of the 690 participants 7.25% reported mild to moderate depression, whereas 0.58 percent had severe or extremely severe depression. Mild to moderate anxiety were found in 9.56% of people, while 2.46% had severe or extremely severe anxiety. Mildly or moderately were stressed 4.78%, while 0.42% was severely or extremely anxious. Alcoholism and depression were found to have a statistically significant relationship (p=0.028). During the COVID-19 pandemic, elderly subjects who napped during the day were substantially less depressed (p=0.033). The older the respondents were, the more nervous they were during the pandemic (p=0.042). There is a link between alcohol consumption and stress (p=0.043) and it was seen that females were more stressed as compared to males (p=0.045). There was a strong correlation between participants' alcohol addiction and depressive symptoms. Psychological therapies for the elderly are thought to be necessary to enhance their psychological resilience and mental health. We need to tackle the stigma related to the COVID-19 and mental health issues.

Association of Different Biochemical and Hemodynamic Characteristic with Type 2 Diabetes Mellitus and Hypertension in Nephrolithiasis Patients

Background Although Nephrolithiasis is a common condition caused by a wide variety of metabolic or environmental disturbances, its being one of the major factor of morbidity. Incidence of kidney stone disease (KSD) is highly affected by metabolic disorders and change in blood pressure and glucose. Objective To find out association of different biochemical and hemodynamic parameters with various glycemic status and hypertension in kidney stone disease. Method A cross sectional study was conducted in patients diagnosed as nephrolithiasis by using re¬nal ultrasonography and underwent nephrectomy between January 2019 to January 2021 in Shahid Dharmabhakta National Transplant Centre (SDNTC). A total of 100 subjects with 60 male and 40 females were enrolled. Glycemic status was categorized based on criteria of American Diabetes Association (ADA) and hypertension was defined as BP ≥ 140/90 mm Hg in right arm supine position. All biochemical and hemodynamic profile was carried out following standard protocol. Result Out of 100 patients enrolled, pre-diabetes accounted for 31% followed by diabetes (4%). However, hypertension comprised of 66% in total subjects. Serum urea, cholesterol and triglyceride level were found to be increased by 84.6%, 67.7% and 64.7% respectively in diabetes followed by increase of 3.9%, 19.5% and 3.1% respectively in prediabetes when compared to normal glycemic condition in nephrolithiasis subjects. Serum fasting blood glucose, creatinine and uric acid level was observed significantly higher (p=0.003, p=0.004, p < 0.001 respectively) in hypertensive patients. Duration of hospital stay was also seen positively correlated with hypertension. Conclusion Not only diabetes, prediabetes also manifests the increased risk of kidney stone disease along with hypertension. There is significant impairment in renal function and lipid profile based on diabetes mellitus and hypertension. Early identifying these systemic diseases, different biochemical and hemodynamic parameters and proper treatment accordingly may minimize risk and prevent serious complication in these patients.

G protein gamma subunit, a hidden master regulator of GPCR signaling

Heterotrimeric G proteins (αβγ subunits) that are activated by G protein-coupled receptors (GPCRs) mediate the biological responses of eukaryotic cells to extracellular signals. The α subunits and the tightly bound βγ subunit complex of G proteins have been extensively studied and shown to control the activity of effector molecules. In contrast, the potential roles of the large family of γ subunits have been less studied. In this review, we focus on present knowledge about these proteins. Induced loss of individual γ subunit types in animal and plant models result in strikingly distinct phenotypes indicating that γ subtypes play important and specific roles. Consistent with these findings, downregulation or upregulation of particular γ subunit types result in various types of cancers. Clues about the mechanistic basis of γ subunit function have emerged from imaging the dynamic behavior of G protein subunits in living cells. This shows that in the basal state, G proteins are not constrained to the plasma membrane but shuttle between membranes and on receptor activation βγ complexes translocate reversibly to internal membranes. The translocation kinetics of βγ complexes varies widely and is determined by the membrane affinity of the associated γ subtype. On translocating, some βγ complexes act on effectors in internal membranes. The variation in translocation kinetics determines differential sensitivity and adaptation of cells to external signals. Membrane affinity of γ subunits is thus a parsimonious and elegant mechanism that controls information flow to internal cell membranes while modulating signaling responses.

Appendiceal Neuroendocrine Tumor Mimicking Acute Appendicitis

Appendiceal carcinoids are the most frequent tumors arising from the appendix, comprising between 32 and 57% of all the appendiceal tumors. The gross appearance of the appendix showed perforation at the tip with 30 ml of periappendicular collection. On histopathological examination, carcinoid tumor on the tip of appendix was found with tumor cells arranged in tubules, acini and nests infiltrating the muscularis propria and sub serosa. Perineural and vascular invasion was not seen. Immunohistochemistry for Synaptophysin was positive with Ki-67 labelling index of 2%. We present a case of appendiceal neuroendocrine tumor with the chief complaint of acute appendicitis.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Correlation between Sonoelastographic, Doppler and Histopathological Findings in Chronic Kidney Disease Patients in Tertiary Care Centre

Background Ultrasound (USG) with Doppler examination of intrarenal vessels is the imaging modality of choice employed in patients with renal failure and is commonly performed early in the clinical course. The pulsatility index (PI) and the resistive index (RI) of downstream renal artery have been found to correlate with renal vascular resistance, filtration fraction and effective renal plasma flow in chronic renal failure. Pathological process in any tissues alters their elastic properties which can be assessed non-invasively through newer technique like elastography. Objective To correlate the findings obtained by sonoelastographic, doppler and histopathological studies in chronic kidney disease patients. Method Study was done in 146 patients referred to Department of Radiodiagnosis and Imaging, TUTH for native renal biopsy. Renal sonographic morphology (length, echogenicity, cortical thickness), Sonoelastography (Young's modulus) and Doppler parameters (peak systolic velocity, resistive index) were assessed. The grading of estimated GFR (eGFR) was calculated based on chronic kidney disease (CKD) criteria. Result Among 146 patients, 63 (43.2%) were females and 83 (56.8%) were males. Maximum patients were in age group of 41-50 years (25.3%) followed by age group 51-60 years (24%). Mean age of patient was 42.06±14.70 for males and 39.57±12.54 females. Maximum mean Young's modulus was seen in eGFR stage G1 with 46.57±19.51 kPa followed by in stage G3a with 36.46±10.01 kPa and observed to be statistically non-significant (p=0.172). However, statistical significance difference was noted between the resistive index and elastographic measurement of Young's modulus (r=0.462, p=0.0001). Minimum mean cortical thickness was seen in eGFR stage G5 with 4.42±1.48 mm followed by stage G4 with 5.57±1.24 mm (p= 0.0001). Cortical thickness is decreasing as eGFR stage was increasing in our study (p=0.0001). Resistive index is increasing with decrease in renal size (r=-0.202, p=0.015). Conclusion Ultrasonography along with doppler study and elastography have limited role in diagnosing the pathology of chronic kidney disease, however, it has significant role in the disease progression.

Perception of Medical Students Regarding TU-IOM MBBS Curriculum and Teaching Learning Methods in Nepal

Background The present Bachelor of Medicine and Bachelor of Surgery (MBBS) curriculum under Tribhuvan University - Institute of Medicine (TU-IOM) was last revised twelve-years back. Though the curriculum was built upon internationally approved recommendations on curriculum design, it is ineffectively practiced in most medical schools of Nepal with major focus on didactic teaching-learning. The curriculum, hence, needs effective implementation and revision. Objective To identify the strengths, weaknesses, and areas of improvement in the medical curriculum through student-based feedback and outline the possibility of incorporating newer evidence-based teaching-learning methodologies in Nepal. Method This is a descriptive and cross-sectional study. With appropriate ethical approval, a questionnaire was developed and disseminated virtually to all medical students of Nepal under TU from MBBS fourth year onwards. The questionnaire comprised of Likert and close-ended questions. The data analysis was followed after receiving the filled questionnaire through Google forms. Result A total of 337 respondents participated in the study. The most effectively implemented components out of the SPICES model were Integrated learning (I) and Communitybased learning (C), with 73.89% and 68.84% responses. There were 94.7% (319) students who favored the incorporation of research in the core curriculum. Only 34.2% (115) students found PowerPoint lectures, the most utilized form of teachinglearning in Nepal, as engaging. The respondents (84.6%) showed a high degree of readiness to incorporate newer evidence-based teaching-learning tools such as flipped learning, blended learning, and peer-to-peer learning. Conclusion This study shows that effective interventions must be rethought on various aspects of the curriculum, taking students' feedback on the table while considering curricular revision.

Round window membrane rupture following blunt force trauma

Round window rupture following barotrauma such as diving and air travel is well documented. However, we describe a case of round window rupture following a slap to the ear, which has not been described previously. A 12-year-old boy was slapped by his teacher in rural Nepal over his left ear and immediately noted hearing loss. There was no dizziness or tinnitus. He presented to our unit 21 days after the trauma and examination showed a perforation of the tympanic membrane in the anterior inferior quadrant with an otherwise normal ear examination and no nystagmus seen. Audiogram showed a left profound hearing loss, which was supported by auditory brainstem response test. Exploratory tympanotomy showed active perilymph leakage from the round window niche as demonstrated in the video attached. The round window was packed with cartilage and fascia to address the perilymph leakage. The patient was discharged the following day without any complications. This is an unusual cause for round window membrane rupture where the patient presented with hearing loss as his only symptom. Tympanotomy is recommended for patients with hearing loss following trauma with normal computed tomography imaging to exclude perilymph leak secondary to inner ear barotrauma.

Cartilaginous Choristoma of Tonsil: A hidden clinical entity

Choristoma is a tumor like mass which is an ectopic rest of normal tissue due to embryological developmental defect. The presence of choristoma in tonsil is extremely rare. On histopathological examination, mature hyaline cartilage were found surrounded by lymphoid follicles. We present a case of cartilaginous choristoma with the complaint of recurrent tonsillitis.

An optogenetic model reveals cell shape regulation through FAK and fascin

Cell shape regulation is important, but the mechanisms that govern shape are not fully understood, in part due to limited experimental models in which cell shape changes and underlying molecular processes can be rapidly and non-invasively monitored in real time. Here, we used an optogenetic tool to activate RhoA in the middle of mononucleated macrophages to induce contraction, resulting in a side with the nucleus that retained its shape and a non-nucleated side that was unable to maintain its shape and collapsed. In cells overexpressing focal adhesion kinase (FAK; also known as PTK2), the non-nucleated side exhibited a wide flat morphology and was similar in adhesion area to the nucleated side. In cells overexpressing fascin, an actin-bundling protein, the non-nucleated side assumed a spherical shape and was similar in height to the nucleated side. This effect of fascin was also observed in fibroblasts even without inducing furrow formation. Based on these results, we conclude that FAK and fascin work together to maintain cell shape by regulating adhesion area and height, respectively, in different cell types. This article has an associated First Person interview with the first author of the paper.

Lipid Profile and Ultrasonographic Grading in Alcoholic and Non Alcoholic Fatty Liver Patients

Background Fatty liver disease (FLD) is a common and major chronic liver disease. It has been implicated that patients have disorders of lipid metabolism and are involved in the pathogenesis of fatty liver. Hence, it was designed to observe the association between lipid profile and fatty liver disease. Objective This study was undertaken to evaluate the association of lipid profile status, hemoglobin and albumin levels with fatty liver disease patients diagnosed based on ultrasonography (USG). Method This Cross-sectional study was undertaken in the Department of Internal Medicine with the collaboration of the Department of Radiology and Department of Biochemistry, Universal College of Medical Sciences-Teaching Hospital (UCMS-TH), Bhairahawa, Nepal from March 2019 to February 2020 in a total of 100 patients diagnosed with fatty liver disease by ultrasonography. The fasting blood was collected for lipid profile and carried out in the automated analyzer following standard protocol. Result In 100 cases, the male to female ratio was 1.8:1. Fifty six percent of the total cases presented with alcoholic fatty liver disease (AFLD) while the remaining 44% with nonalcoholic fatty liver disease (NAFLD). The spectrum of lipid abnormality was observed with increased total cholesterol (TC), Low Density Lipoprotein (LDL), increased triglycerides (TG), Very Low Density Lipoprotein (VLDL) in alcoholic fatty liver disease cases as compared to nonalcoholic fatty liver disease cases. However, it has been observed that TG/HDL and Non-HDL/HDL were higher in nonalcoholic fatty liver disease as compared to alcoholic fatty liver disease. Moreover, a statistically significant difference was observed in HDL between AFLG2 and NAFLG2 (p-value: 0.012). Conclusion Dyslipidemia and decreased HDL have been implicated in fatty liver diseases. USG in conjunction with Non-HDL/HDL, TG/HDL, hemoglobin, and albumin can be useful in early screening and monitoring of dyslipidemia in fatty liver patients.

A photoswitchable GPCR-based opsin for presynaptic inhibition

Optical manipulations of genetically defined cell types have generated significant insights into the dynamics of neural circuits. While optogenetic activation has been relatively straightforward, rapid and reversible synaptic inhibition has proven more elusive. Here, we leveraged the natural ability of inhibitory presynaptic GPCRs to suppress synaptic transmission and characterize parapinopsin (PPO) as a GPCR-based opsin for terminal inhibition. PPO is a photoswitchable opsin that couples to Gi/o signaling cascades and is rapidly activated by pulsed blue light, switched off with amber light, and effective for repeated, prolonged, and reversible inhibition. PPO rapidly and reversibly inhibits glutamate, GABA, and dopamine release at presynaptic terminals. Furthermore, PPO alters reward behaviors in a time-locked and reversible manner in vivo. These results demonstrate that PPO fills a significant gap in the neuroscience toolkit for rapid and reversible synaptic inhibition and has broad utility for spatiotemporal control of inhibitory GPCR signaling cascades.

SRRF-Stream Imaging of Optogenetically Controlled Furrow Formation Shows Localized and Coordinated Endocytosis and Exocytosis Mediating Membrane Remodeling

Cleavage furrow formation during cytokinesis involves extensive membrane remodeling. In the absence of methods to exert dynamic control over these processes, it has been a challenge to examine the basis of this remodeling. Here we used a subcellular optogenetic approach to induce this at will and found that furrow formation is mediated by actomyosin contractility, retrograde plasma membrane flow, localized decrease in membrane tension, and endocytosis. FRAP, 4-D imaging, and inhibition or upregulation of endocytosis or exocytosis show that ARF6 and Exo70 dependent localized exocytosis supports a potential model for intercellular bridge elongation. TIRF and Super Resolution Radial Fluctuation (SRRF) stream microscopy show localized VAMP2-mediated exocytosis and incorporation of membrane lipids from vesicles into the plasma membrane at the front edge of the nascent daughter cell. Thus, spatially separated but coordinated plasma membrane depletion and addition are likely contributors to membrane remodeling during cytokinetic processes.

Traditional Fermented Indian Foods: A Treasure Hunt for Rare Lactic Acid Bacteria

The article's abstract is no available.

Physical Plasma Membrane Perturbation Using Subcellular Optogenetics Drives Integrin-Activated Cell Migration

Cells experience physical deformations to the plasma membrane that can modulate cell behaviors like migration. Understanding the molecular basis for how physical cues affect dynamic cellular responses requires new approaches that can physically perturb the plasma membrane with rapid, reversible, subcellular control. Here we present an optogenetic approach based on light-inducible dimerization that alters plasma membrane properties by recruiting cytosolic proteins at high concentrations to a target site. Surprisingly, this polarized accumulation of proteins in a cell induces directional amoeboid migration in the opposite direction. Consistent with known effects of constraining high concentrations of proteins to a membrane in vitro, there is localized curvature and tension decrease in the plasma membrane. Integrin activity, sensitive to mechanical forces, is activated in this region. Localized mechanical activation of integrin with optogenetics allowed simultaneous imaging of the molecular and cellular response, helping uncover a positive feedback loop comprising SFK- and ERK-dependent RhoA activation, actomyosin contractility, rearward membrane flow, and membrane tension decrease underlying this mode of cell migration.

Optogenetic Control of Cell Migration

Subcellular optogenetics allows specific proteins to be optically activated or inhibited at a restricted subcellular location in intact living cells. It provides unprecedented control of dynamic cell behaviors. Optically modulating the activity of signaling molecules on one side of a cell helps optically control cell polarization and directional cell migration. Combining subcellular optogenetics with live cell imaging of the induced molecular and cellular responses in real time helps decipher the spatially and temporally dynamic molecular mechanisms that control a stereotypical complex cell behavior, cell migration. Here we describe methods for optogenetic control of cell migration by targeting three classes of key signaling switches that mediate directional cellular chemotaxis-G protein coupled receptors (GPCRs), heterotrimeric G proteins, and Rho family monomeric G proteins.

Subcellular optogenetic activation of Cdc42 controls local and distal signaling to drive immune cell migration

Cdc42 is believed to play an important role in controlling the polarity of migrating cells, but it has not been possible to directly determine the effects of localized Cdc42 activity. Optogenetic activation of Cdc42 at one side of the cell was used to identify local and distal signaling responses that contribute to directed cell migration.

Migratory immune cells use intracellular signaling networks to generate and orient spatially polarized responses to extracellular cues. The monomeric G protein Cdc42 is believed to play an important role in controlling the polarized responses, but it has been difficult to determine directly the consequences of localized Cdc42 activation within an immune cell. Here we used subcellular optogenetics to determine how Cdc42 activation at one side of a cell affects both cell behavior and dynamic molecular responses throughout the cell. We found that localized Cdc42 activation is sufficient to generate polarized signaling and directional cell migration. The optically activated region becomes the leading edge of the cell, with Cdc42 activating Rac and generating membrane protrusions driven by the actin cytoskeleton. Cdc42 also exerts long-range effects that cause myosin accumulation at the opposite side of the cell and actomyosin-mediated retraction of the cell rear. This process requires the RhoA-activated kinase ROCK, suggesting that Cdc42 activation at one side of a cell triggers increased RhoA signaling at the opposite side. Our results demonstrate how dynamic, subcellular perturbation of an individual signaling protein can help to determine its role in controlling polarized cellular responses.

A G-protein subunit translocation embedded network motif underlies GPCR regulation of calcium oscillations

G-protein βγ subunits translocate reversibly from the plasma membrane to internal membranes on receptor activation. Translocation rates differ depending on the γ subunit type. There is limited understanding of the role of the differential rates of Gβγ translocation in modulating signaling dynamics in a cell. Bifurcation analysis of the calcium oscillatory network structure predicts that the translocation rate of a signaling protein can regulate the damping of system oscillation. Here, we examined whether the Gβγ translocation rate regulates calcium oscillations induced by G-protein-coupled receptor activation. Oscillations in HeLa cells expressing γ subunit types with different translocation rates were imaged and quantitated. The results show that differential Gβγ translocation rates can underlie the diversity in damping characteristics of calcium oscillations among cells. Mathematical modeling shows that a translocation embedded motif regulates damping of G-protein-mediated calcium oscillations consistent with experimental data. The current study indicates that such a motif may act as a tuning mechanism to design oscillations with varying damping patterns by using intracellular translocation of a signaling component.

Optimizing optogenetic constructs for control over signaling and cell behaviours

Optogenetic tools have recently been developed that enable dynamic control over the activities of select signaling proteins. They provide the unique ability to rapidly turn signaling events on or off with subcellular control in living cells and organisms. This capability is leading to new insights into how the spatial and temporal coordination of signaling events governs dynamic cell behaviours such as migration and neurite outgrowth. These tools can also be used to dissect a protein's signaling functions at different organelles. Here we review the properties of photoreceptors from diverse organisms that have been leveraged to control signaling in mammalian cells. We emphasize recent engineering approaches that have been used to create optogenetic constructs with optimized spectral, kinetic, and signaling properties for controlling cell behaviours.

Chemical, Bioactive, and Antioxidant Potential of Twenty Wild Culinary Mushroom Species

The chemical, bioactive, and antioxidant potential of twenty wild culinary mushroom species being consumed by the people of northern Himalayan regions has been evaluated for the first time in the present study. Nutrients analyzed include protein, crude fat, fibres, carbohydrates, and monosaccharides. Besides, preliminary study on the detection of toxic compounds was done on these species. Bioactive compounds evaluated are fatty acids, amino acids, tocopherol content, carotenoids (β-carotene, lycopene), flavonoids, ascorbic acid, and anthocyanidins. Fruitbodies extract of all the species was tested for different types of antioxidant assays. Although differences were observed in the net values of individual species all the species were found to be rich in protein, and carbohydrates and low in fat. Glucose was found to be the major monosaccharide. Predominance of UFA (65-70%) over SFA (30-35%) was observed in all the species with considerable amounts of other bioactive compounds. All the species showed higher effectiveness for antioxidant capacities.

Comparative study of glycated hemoglobin by ion exchange chromatography and affinity binding nycocard reader in type 2 diabetes mellitus

The aim of this study was to compare the level of glycated hemoglobin (HbA1c) in type 2 Diabetes Mellitus (DM) patients by two different methods namely Ion Exchange Chromatography and Affinity Binding Nycocard Reader. This is a cross-sectional study conducted on confirmed type 2 diabetes mellitus patients (n = 100) who visited Out Patients Department of the Universal College of Medical Sciences Teaching hospital, Bhairahawa, Nepal from November 2012 to March 2013. The diagnosis of diabetes mellitus was done on the basis of their fasting (164.46 ± 45.33 mg/dl) and random (187.93 ± 78.02 mg/dl) serum glucose level along with clinical history highly suggestive of type 2 DM. The HbA1c values of (7.8 ± 1.9%) and (8.0 ± 2.2%) were found in DM patients as estimated by those two different methods respectively. The highest frequency was observed in HbA1c > 8.0% indicating maximum cases were under very poor glycemic control. However, there were no significant differences observed in HbA1c value showing both methods are comparable in nature and can be used in lab for ease of estimation. The significant raised in HbA1c indicates complications associated with DM and monitoring of therapy become hard for those patients. Despite having standard reference method for HbA1c determination, the availability of report at the time of the patient visit can be made easy by using Nycocard Reader and Ion Exchange Chromatography techniques without any delay in communicating glycemic control, clinical decision-making and changes in treatment regimen.

The structure of dynamic GPCR signaling networks

G-protein-coupled receptors (GPCRs) stimulate signaling networks that control a variety of critical physiological processes. Static information on the map of interacting signaling molecules at the basis of many cellular processes exists, but little is known about the dynamic operation of these networks. Here we focus on two questions. First, Is the network architecture underlying GPCR-activated cellular processes unique in comparison with others such as transcriptional networks? We discuss how spatially localized GPCR signaling requires uniquely organized networks to execute polarized cell responses. Second, What approaches overcome challenges in deciphering spatiotemporally dynamic networks that govern cell behavior? We focus on recently developed microfluidic and optical approaches that allow GPCR signaling pathways to be triggered and perturbed with spatially and temporally variant input while simultaneously visualizing molecular and cellular responses. When integrated with mathematical modeling, these approaches can help identify design principles that govern cell responses to extracellular signals. We outline why optical approaches that allow the behavior of a selected cell to be orchestrated continually are particularly well suited for probing network organization in single cells.

Subcellular optogenetic inhibition of G proteins generates signaling gradients and cell migration

Cells sense gradients of extracellular cues and generate polarized responses such as cell migration and neurite initiation. There is static information on the intracellular signaling molecules involved in these responses, but how they dynamically orchestrate polarized cell behaviors is not well understood. A limitation has been the lack of methods to exert spatial and temporal control over specific signaling molecules inside a living cell. Here we introduce optogenetic tools that act downstream of native G protein-coupled receptor (GPCRs) and provide direct control over the activity of endogenous heterotrimeric G protein subunits. Light-triggered recruitment of a truncated regulator of G protein signaling (RGS) protein or a Gβγ-sequestering domain to a selected region on the plasma membrane results in localized inhibition of G protein signaling. In immune cells exposed to spatially uniform chemoattractants, these optogenetic tools allow us to create reversible gradients of signaling activity. Migratory responses generated by this approach show that a gradient of active G protein αi and βγ subunits is sufficient to generate directed cell migration. They also provide the most direct evidence so for a global inhibition pathway triggered by Gi signaling in directional sensing and adaptation. These optogenetic tools can be applied to interrogate the mechanistic basis of other GPCR-modulated cellular functions.

Liquid chromatography tandem mass spectrometry method for determination of antidiabetic chalcones derivative S001-469 in rat plasma, urine and feces: application to pharmacokinetic study

A sensitive and selective liquid chromatography tandem mass spectrometry assay was developed for quantitation of a novel antidiabetic chalcones derivative S001-469 in rat matrices. Plasma and urine samples were prepared by double liquid-liquid extraction with diethyl ether and feces by protein precipitation using acetonitrile. Chromatographic elution was carried on cyano guard column (30 mm × 4.6 mm i.d., 5 µm) in isocratic mode at a flow rate of 0.75 mL/min using mobile phase comprising of methanol: ammonium acetate buffer (pH 4.6, 10 mM) (90:10, v/v). Run time was 6 min. Detection was achieved by employing positive ionization mode on a triple-quadrupole LC-MS/MS system with an electrospray ionization (ESI) source. The calibration curves were linear over the range of 0.78-400 ng/mL for all 3 matrices. The method was validated and proved reliable through high and consistent intra- and inter- day accuracy and precision (<15%) values. Recoveries was >85% from spiked plasma, urine and feces samples. S001-469 was stable in plasma at room temperature till 8 h and at -60 °C for 30 d and 3 freeze-thaw cycles.

Serum total adenosine deaminase activity in Nepalese patients with Rheumatoid Arthritis

Objective: Several studies indicate that serum adenosine deaminase (ADA) activity could be a potential marker for the diagnosis of patients with rheumatoid arthritis (RA). However, there has been no such study that could independently verify this finding in Nepali population. The present study therefore aims to measure the total ADA activity in the sera of Nepalese RA patients and verify its diagnostic potential. Materials and Methods: A total of 69 RA patients who visited Universal College of Medical Sciences Teaching Hospital (UCMSTH), Bhairahawa, Nepal for their medical treatment were enrolled for this study. An equal number of age and sex-matched healthy controls were also included in the study. Blood samples were collected from each study subjects and analyzed for serum total ADA, Creactive protein (CRP) and rheumatoid factor (RF). Results: Serum total ADA activity was found to be significantly (p<0.0001) higher (30.0 }10.1 U/L) in all RA patients compared to healthy controls (13.5 } 3.6 U/L). However, no significant difference (p>0.05) in the ADA activity was found between the smokers and non-smoker RA patients. Out of total 69 RA patients, only 16 (23.1%) were positive for CRP and 11 (15.9%) were positive for RF. Conclusion: Measurement of serum total ADA activity could be a reliable marker for the diagnosis of RA in Nepali population with relevant clinical scenarios when there is absence of CRP and RF in the serum.  DOI: http://dx.doi.org/10.3126/ajms.v4i2.6208 Asian Journal of Medical Sciences 4(2013) 30-35

Effect of carbamazepine on the pharmacokinetic parameters of CDRI-97/78 following coadministration to rats

Coadministration of 2 or more drugs may result in unexpected toxicity. This study aimed to evaluate the effect of carbamazepine coadministration on the pharmacokinetics of CDRI-97/78, an 1,2,4-trioxane antimalarial agent. Firstly, 97/78 was administered alone and then 97/78 and carbamazepine were coadministered to male and female rats. An revalidated LC-MS/MS method was used for quantitation of 97/63 since 97/78 is instantly and completely converted to 97/63 (an in-vivo active metabolite). The Tmax and Cmax values of 97/63 were 1.75±0.77 h and 862±306 ng/mL in male rats whereas in female rats they were 5.45±0.76 h and 662.75±95.09 ng/mL after a single dose of 97/78 alone. However, following coadministration of 97/78 and carbamazepine, the values for Tmax and Cmax were 1.06±0.16 h and 533±153 ng/mL in male rats and 2.23±1.93 h and 636.5±112.4 ng/mL in female rats. The half life of 97/63 following a single oral dose of 97/78 or coadministration with carbamazepine to male rats was 6.98±0.63 h and 6.64±0.54 h, respectively; the values in female rats were 7.5±0.5 h and 5.48±0.37 h. A statistically insignificant difference (P>0.05) was observed with the student t-test for the pharmacokinetic parameters of 97/63 following oral administration of 97/78 alone or coadministration of 97/78 and carbamazepine except for MRT in female rats. Intersex statistical comparison also showed an insignificant difference for 97/63 following oral administration of 97/78 alone or in combination with carbamazepine except for MRT, which supports coadministration of 97/78 and carbamazepine.

Frequency of Type 2 Diabetes mellitus and Impaired Glycemia in a Teaching Hospital of South-Western Nepal

Objective: The aim of this study was to determine the frequency of type 2 diabetes, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) among patients visiting a tertiary level teaching hospital in south-western Nepal. Material & Methods: This is a retrospective study conducted among subjects (n=17082) who visited outpatient department of the Universal College of Medical Sciences Teaching Hospital (UCMSTH), Bhairahawa, Nepal for their medical checkup.  Data related to age, sex, hospital number and blood glucose concentration of the study subjects were collected from hospital records and analyzed for the frequency study. Results: The average frequency of type 2 diabetes was found to be 6.1% over a period of five years and it was significantly (p=0.0232) higher in males (3.4%) than in females (2.8%). Frequency of IFG and IGT were found to be 2.31% and 2.70% respectively. The frequency of type 2 diabetes, IFG and IGT was significantly higher in males and age group of 51-60 years. Conclusion: The frequency of type 2 diabetes and impaired glycemia is increasing every year in south-western part of Nepal. We recommend that efforts be made by all the stakeholders to curb this emerging medical problem before it becomes epidemic in the general population. DOI: http://dx.doi.org/10.3126/ajms.v2i3.5485 Asian Journal of Medical Sciences 2 (2011) 202-206  

All G protein βγ complexes are capable of translocation on receptor activation

Heterotrimeric G proteins transduce signals sensed by transmembrane G protein coupled receptors (GPCRs). A subfamily of G protein βγ subunit types has been shown to selectively translocate from the plasma membrane to internal membranes on receptor activation. Using 4D imaging we show here that Gβγ translocation is not restricted to some subunit types but rather all 12 members of the family of mammalian γ subunits are capable of supporting βγ translocation. Translocation kinetics varies widely depending on the specific γ subunit type, with t(1/2) ranging from 10s to many minutes. Using fluorescence complementation, we show that the β and γ subunits translocate as βγ dimers with kinetics determined by the γ subunit type. The expression patterns of endogenous γ subunit types in HeLa cells, hippocampal neurons and cardiomyocytes are distinctly different. Consistent with these differences, the βγ translocation rates vary widely. βγ translocation rates exhibit the same γ subunit dependent trends regardless of the specific receptor type or cell type showing that the translocation rates are intrinsic to the γ subunit types. βγ complexes with widely different rates of translocation had differential effects on muscarinic stimulation of GIRK channel activity. These results show that G protein βγ translocation is a general response to activation of GPCRs and may play a role in regulating signaling activity.

Intersex effect of lamotrigine on the pharmacokinetic parameters of CDRI-97/78, a novel trioxane antimalarial compound, in rats

Reports regarding drug toxicity and adverse events resulting from coadministration of multiple drugs are increasing at an alarming rate. CDRI-97/78 is an 1,2,4-trioxane antimalarial agent under development which gets metabolized to the in vivo active metabolite 97/63. In order to assess its drug interaction potential, CDRI-97/78 was administered alone and in combination with lamotrigine to male and female rats via the oral route. Quantification of the active metabolite 97/63 in rat plasma was achieved with an LC-MS/MS assay. After oral administration of 97/78, the Tmax and Cmax values of 97/63 in male rats were 1.75±0.77 h and 862±306 ng/mL while female rats showed values for Cmax of 622.75±95.09 ng/mL and for Tmax of 7.5±0.5 h. Coadministration of 97/78 and lamotrigine resulted in decreased Tmax and Cmax values in both male and female rats (Tmax and Cmax of 0.77±0.16 h and 58.58±6.43 ng/mL in male rats; 1.13±0.22 h and 62.95±12.00 ng/mL in female rats, respectively). A statistically significant difference (P<0.05) was observed for the pharmacokinetic parameters of 97/63 after oral administration of 97/78 alone and upon its coadministration with lamotrigine except for the Cmax and Tmax values in male and for the T1/2 value in female rats. Statistically, no significant difference for the pharmacokinetic parameters of 97/63 between male and female rats after oral administration of 97/78 alone or in combination with lamotrigine was determined except for Tmax. The study indicates that coadministration of 97/78, an antimalarial agent, and the antiepileptic lamotrigine may require dose adjustments. Additional clinical drug interaction trials may be required to confirm these findings.

Upper gastro-intestinal bleeding: aetiology and demographic profile based on endoscopic examination at Dhulikhel Hospital, Kathmandu University Hospital

BACKGROUND

The upper gastrointestinal bleeding (UGIB) is defined as bleeding within the intraluminal gastrointestinal tract from any location between the upper oesophagus to the duodenum at the ligament of Treitz. It is one of the important medical emergencies worldwide.

OBJECTIVE

The objective of this study is to study the aetiology of upper gastrointestinal bleeding based on endoscopic examination findings in patients of various demographic characteristics.

MATERIALS AND METHODS

This is a retrospective observational study. The endoscopic record book from 2007 January to 2009 October was reviewed for all the cases who underwent oesophago-gastro-duodenoscopic examination for upper GI bleeding. The clinico-epidemiological data of all the patients was reviewed and analyzed in concert with the aetiology of bleeding.

RESULTS

A total of 90 patients (58 males, 32 females; mean age 45.32+ 18.47 years) of upper gastrointestinal bleeding was studied and analyzed in terms of aetiology of bleeding and demographic profile. Among the ethnic groups, Aryan 46 (51%) was the most common ethnic group to have upper GI bleeding followed by Newars 24 (27%), Mongolians 16 (18%), Dalits 3 (3%) and others 1 (1%). Out of 90 patients, 47( 52.2%) cases was less than 45 years of age, 30(33.3%) of 46 to 65 age ; and 13(14.4 %) more than 65 years of age. Gastric ulcer 23(25.6%) was the most common endoscopic finding, followed by oesophageal varices 14 (15.6%), acute erosive/haemorrhagic gastropathy 11 (12.2%), duodenal ulcer 9(10%), growth 7(7.8%), vascular lesions 3(3.3%), Mallory-Weiss tear 1(1.1%), fundal varices 1(1.1%) and, no cause was identified in 21(23.3%) cases. The peptic ulcer bleeding was the most common finding in Aryan 22(47.9%), whereas oesophageal varices and growth were more common in Newar 7(29.2%) and 3 (12.5%) respectively.

CONCLUSION

Peptic ulcer disease is the most common cause of upper GI bleeding which was most commonly found in Aryan population; followed by oesophageal varices and growth as second and third most common causes and were more prevalent in Newar and Mongolian people.

Alteration of Golgi structure in senescent cells and its regulation by a G protein γ subunit

Cellular senescence is a process wherein proliferating cells undergo permanent cell cycle arrest while remaining viable. Senescence results in enhanced secretion of proteins that promote cancer and inflammation. We report here that the structure of the Golgi complex which regulates secretion is altered in senescent cells. In cells where senescence is achieved by replicative exhaustion or in cells wherein senescence has been induced with BrdU treatment dependent stress, the Golgi complex is dispersed. The expression of a G protein γ subunit, γ11, capable of translocation from the plasma membrane to the Golgi complex on receptor activation increases with senescence. Knockdown of γ11 or overexpression of a dominant negative γ3 subunit inhibits Golgi dispersal induced by senescence. Overall these results suggest that in cellular senescence an upregulated G protein gamma subunit mediates alterations in the structure of the Golgi.

Liquid chromatographic-tandem mass spectrometry assay for quantitation of a novel antidiabetic S002-853 in rat plasma and its application to pharmacokinetic study

A sensitive and selective LC-MS/MS method has been developed and validated for the estimation of novel antidiabetic synthetic flavonoid S002-853 in rat plasma using centchroman as an internal standard. The method involves a simple two-step liquid-liquid extraction with diethyl ether. The analyte was chromatographed on a Pierce Spheri-5, guard cyano column (30 x 4.6 mm i.d., 5 microm) with isocratic mobile phase consisting of methanol-ammonium acetate buffer (pH 4.6, 10 mm; 90 : 10, v/v) at a flow rate of 0.75 mL/min. The API 4000 triple-quadrupole LC-MS/MS system was operated under multiple reaction-monitoring mode. The ionization was performed by electrospray ionization technique in positive ion mode. The chromatographic run time was 6 min and the weighted (1/x(2)) calibration curves were linear over the range 0.78-400 ng/mL. The limit of detection and lower limit of quantification were 0.195 and 0.78 ng/mL, respectively. The intra- and inter-batch accuracy (%bias) and precision (%RSD) were found to be less than 8.47 and 11.6% respectively. The average absolute recoveries of S002-853 and internal standard from spiked plasma samples were >90%. S002-853 was stable for 8 h at ambient temperature, 4 weeks at -60 degrees C and after three freeze-thaw cycles. The assay was successfully applied to determine the pharmacokinetic parameters in male Sprague-Dawley rats after an oral dose administration at 25 mg/kg.

Transient left ventricular apical ballooning post-pneumoperitoneum: Takotsubo cardiomyopathy. A case report

The aim of this study was to describe the clinical features and management of Takotsubo cardiomyopathy manifesting during the intraoperative period in a patient undergoing laparoscopic cholecystectomy.

CLINICAL FEATURES

a 29-year-old ASA I female patient was posted for laparoscopic cholecystectomy. A standard general anesthetic technique was followed. Two minutes after the initiation of pneumoperitoneum, the patient developed clinical features of acute myocardial infarction with pulmonary edema. The surgery was postponed and the patient was shifted to the ICU. Echocardiography revealed hypokinesis of the left ventricle apex and anterolateral segment. Coronary angiography revealed normal arteries without any stenosis or obstruction. The patient required vasopressor and inotropic support for 4 days and was discharged on the 8th postoperative day. Repeat echocardiography 4 days later demonstrated complete resolution of regional systolic dysfunction. Transient left ventricular dysfunction is a possible occurrence during non-cardiac surgery. Awareness of this condition is essential as early diagnosis and prompt management can save the patient's life. To our knowledge this represents the first case of pneumoperitoneum-induced Takotsubo cardiomyopathy.

With a pinch of salt

This report highlights a case of severe hyponatraemia secondary to excessive sweating and salt [corrected] poor fluid consumption and low salt diet in hot conditions. The case was complicated by the presence of marked hypokalaemia caused by secondary hyperaldosteronism confirmed, for the first time, by the presence of grossly elevated serum renin and aldosterone concentrations. With the rise in global temperature affecting even temperate climates doctors, especially in acute and general medicine, may be faced with this condition more often.