Epitope Mapping of SERCA2a Identifies an Antigenic Determinant That Induces Mainly Atrial Myocarditis in A/J Mice.

Sarcoplasmic/endoplasmic reticulum Ca2+ adenosine triphosphatase (SERCA)2a, a critical regulator of calcium homeostasis, is known to be decreased in heart failure. Patients with myocarditis or dilated cardiomyopathy develop autoantibodies to SERCA2a suggesting that they may have pathogenetic significance. In this report, we describe epitope mapping analysis of SERCA2a in A/J mice that leads us to make five observations: 1) SERCA2a contains multiple T cell epitopes that induce varying degrees of myocarditis. One epitope, SERCA2a 971-990, induces widespread atrial inflammation without affecting noncardiac tissues; the cardiac abnormalities could be noninvasively captured by echocardiography, electrocardiography, and magnetic resonance microscopy imaging. 2) SERCA2a 971-990-induced disease was associated with the induction of CD4 T cell responses and the epitope preferentially binds MHC class II/IAk rather than IEk By creating IAk/and IEk/SERCA2a 971-990 dextramers, the T cell responses were determined by flow cytometry to be Ag specific. 3) SERCA2a 971-990-sensitized T cells produce both Th1 and Th17 cytokines. 4) Animals immunized with SERCA2a 971-990 showed Ag-specific Abs with enhanced production of IgG2a and IgG2b isotypes, suggesting that SERCA2a 971-990 can potentially act as a common epitope for both T cells and B cells. 5) Finally, SERCA2a 971-990-sensitized T cells were able to transfer disease to naive recipients. Together, these data indicate that SERCA2a is a critical autoantigen in the mediation of atrial inflammation in mice and that our model may be helpful to study the inflammatory events that underlie the development of conditions such as atrial fibrillation in humans.

Bioaccumulation of TBT and Its Cellular Toxic Effects on the Freshwater Prawn Macrobrachium rosenbergii.

To test the toxic effects of tributyltin (TBT), Macrobrachium rosenbergii were exposed to three concentrations of TBT viz. 10 ng/L, 100 ng/L and 1000 ng/L for 90 days. The bioaccumulation of TBT level varied in hepatopancreas based upon dose dependent manner. Histopathological results revealed the reduction in basement membrane thickness, disruption of the hepatopancreatic tubules and abnormal lumen in hepatopancreas of TBT treated prawns. The ultrastructure of the control prawn showed normal architecture of cellular organelles with prominent nuclei in hepatocytes. On the other hand, many vacuoles, irregular arrangements of microvilli, swollen mitochondria, distorted rough endoplasmic reticulum cisternaes and abnormal nucleus were seen in the TBT treated group. Further, the biochemical and vitellogenin content were altered remarkably due to TBT exposure. It directly indicated that TBT had conspicuously inhibited the vitellogenesis. Therefore, it was inferred that the administration of TBT has considerably affected the hepatopancreatic functions in M. rosenbergii.

Determinants of disability among the elderly population in a rural south Indian community: the need to study local issues and contexts.

BACKGROUND: Disability among the elderly is a cause of significant burden. There is dearth of relevant research from low- and middle-income countries. We aimed to establish the nature and factors associated with disability among the elderly in a rural south Indian community. METHODS: We recruited 1000 participants aged over 65 years from Kaniyambadi block, Vellore, India. We assessed their disability status, sociodemographic profile, psychiatric morbidity, cognitive functioning and anthropometrics using the following structured instruments: WHO Disability Assessment Scale II, Geriatric Mental State, Community Screening Instrument for Dementia, and Neuropsychiatric Inventory. We employed appropriate multivariate statistics to study the factors associated with a higher level of disability and to determine the population attributable fractions for various modifiable risk factors. RESULTS: Advanced age, illiteracy, hunger, poor nutrition, arthritis, hearing impairment, gastro-intestinal and respiratory diseases, dementia and travel costs to primary health facilities increased the risk of disability significantly. Hypertension, diabetes and depression were not associated with disability. Modifiable social determinants and medical diseases together contributed to disability in this population. CONCLUSION: Locally relevant social determinants combine with prevalent medical diseases to produce the disability burden among elderly. There is a need to focus on local contexts and modifiable risk factors to design locally appropriate public health policies and interventions.

Nature and determinants of out-of-pocket health expenditure among older people in a rural Indian community.

BACKGROUND: Increasing out-of-pocket health expenditure among older people worsens the inequitable access to essential health services in low and middle-income countries (LMIC). We investigated various socioeconomic and health factors associated with out-of-pocket and catastrophic health expenditures among rural older people in India. METHODS: We recruited 1,000 participants aged above 65 years from Kaniyambadi block, Vellore, India. We assessed their out-of-pocket health expenditure, health service utilization, socioeconomic profiles, disability, cognition, and health status by standard instruments. We employed appropriate multivariate statistics evaluating these determinants. RESULTS: Male gender, poor sanitation, diabetes, tuberculosis, malaria, respiratory ailments, gastrointestinal diseases, dementia, depression, and disability were associated with higher out-of-pocket expenditures. Illiteracy, tuberculosis, diabetes, and dementia increased the risk for catastrophic health expenditures, while pension schemes protected against it. Income inequalities were associated with inequities on education, disease prevalence, and access to safe water, sanitation, and nutrition. CONCLUSIONS: Interactions between determinants of out-of-pocket health expenditure, economic inequality, and inequities on essential health care delivery to older people are complex. We highlight the need for equitable health services and policies, focusing on both medical and social determinants.

Prospective study of the long-term outcomes and complications after total temporomandibular joint replacement: analysis at 10 years.

This prospective analysis was performed to assess the long-term benefits of the TMJ Concepts joint replacement system in the UK. All patients who had replacement temporomandibular joints (TMJ) with at least 10 years of follow-up were included. The most common primary diagnoses were trauma, multiple previous operations, psoriatic arthritis, rheumatoid arthritis, degenerative disease, and ankylosis. A total of 43 patients (62 joints) were followed up for 10 years (mean age 45, range 22-70 years); 39 were female and four were male. The mean number of previous TMJ procedures was 2.5 (range 0-10). Over the 10 years of follow-up, there were significant improvements in pain score (10-point scale; decreased from 7.4 to 1.7), maximum mouth opening (increased from 21.0 mm to 34.7 mm), and dietary score (10-point scale; increased from 4.1 to 9.5). Joints in two patients failed, one secondary to a local dental infection and one due to reankylosis. None failed due to wear of the prosthesis, whether the prosthesis was standard cobalt-chrome or all-titanium. Total TMJ replacement gives good long-term improvements, both lessening pain and improving function, and is an effective form of management for irreparably damaged joints.

Characterization and distribution of microplastics in estuarine surface sediments, Kayamkulam estuary, southwest coast of India.

The present study aims to formulate the characterization and distribution of microplastic in the estuarine surface sediments of Kayamkulam estuary, southwest coast of India. The sediments were dominated by fibre and film shaped microplastic substances. The surface sediments were dominated by <1000 µm microplastics. The composition of microplastics in descending order was as follows: polyester > polypropylene > polyethylene. The distribution of microplastics was significantly higher than that observed in the other study regions, except for Pearl river estuary and Guanabara Bay. The distribution of microplastics was chiefly controlled by estuarine inundating water and the distance of the sampling site from the open sea.

Risk factors for suicide in rural south India.

BACKGROUND: The relative contributions of psychosocial stress and psychiatric morbidity to suicide are a subject of debate. AIMS: To determine major risk factors for suicide in rural south India. METHOD: We used a matched case-control design and psychological autopsy to assess 100 consecutive suicides and 100 living controls matched for age, gender and neighbourhood. RESULTS: Thirty-seven (37%) of those who died by suicide had a DSM-III-R psychiatric diagnosis. Alcohol dependence (16%) and adjustment disorders (15%) were the most common categories. The prevalence rates for schizophrenia, major depressive episode and dysthymia were 2% each. Ongoing stress and chronic pain heightened the risk of suicide. Living alone and a break in a steady relationship within the past year were also significantly associated with suicide. CONCLUSIONS: Psychosocial stress and social isolation, rather than psychiatric morbidity, are risk factors for suicide in rural south India.

Bioavailable trace metals and their ecological risks in the tourist beaches of the Southeast coast of India.

The concentration of Acid Leachable Trace Metals (ALTMs) was assessed in urbanized tourist beaches (96 samples from Marina beach, 34 samples from Edward Elliot's beach, and 28 samples from Silver beach) of southeast coast of India. The concentration of metals accumulated in the beach sediment was less than the Upper Continental Crust (UCC) background reference values. The mean enrichment of ALTMs in the studied urban tourist beaches showed the following descending order: Marina beach - Cr > Pb > Ni > Zn > Cu > Mn > Co; Edward Elliot's beach - Cr > Pb > Ni > Mn > Co > Zn > Cu; Silver beach - Cr > Pb > Ni > Co > Mn > Cu > Zn. The ALTMs such as Fe, Mn, Co, Cu, and Zn were probably derived from natural weathering and mild anthropogenic influences whereas other metals were derived from anthropogenic induced factors.

Methane and nitrous oxide fluxes in the polluted Adyar River and estuary, SE India.

We measured dissolved N(2)O, CH(4), O(2), NH(4)(+), NO(3)(-) and NO(2)(-) on 7 transects along the polluted Adyar River-estuary, SE India and estimated N(2)O and CH(4) emissions using a gas exchange relation and a floating chamber. High NO(2)(-) implied some nitrification of a large anthropogenic NH(4)(+) pool. In the lower catchment CH(4) was maximal (6.3+/-4.3 x 10(4)nM), exceeding the ebullition threshold, whereas strong undersaturation of N(2)O and O(2) implied intense denitrification. Emissions fluxes for the whole Adyar system approximately 2.5 x 10(8) g CH(4)yr(-1) and approximately 2.4 x 10(6)gN(2)O yr(-1) estimated with a gas exchange relation and approximately 2 x 10(9) g CH(4)yr(-1) derived with a floating chamber illustrate the importance of CH(4) ebullition. An equivalent CO(2) flux approximately 1-10 x 10(10)gy r(-1) derived using global warming potentials is equivalent to total Chennai motor vehicle CO(2) emissions in one month. Studies such as this may inform more effective waste management and future compliance with international emissions agreements.

Chronic psychosis associated with vitamin B12 deficiency.

B12 deficiency is widely prevalent and usually presents with haematologic and neuropsychiatric manifestations. Psychiatric symptoms seldom precede anaemia and present as the principal manifestation of B12 deficiency. A report an unusual presentation of long standing psychotic symptoms without anaemia in a 31 year old male, who presented to a tertiary care psychiatric facility. His physical examination revealed hyper pigmentation of extremities and posterior column involvement. Laboratory investigations confirmed normal haemoglobin and low serum B12 levels. He recovered dramatically with short term anti psychotic medication and intramuscular cobalamin supplementation. He remained asymptomatic and functionally independent at two years follow up.

Multi-drug overdose risperidone, ziprasidone, valproate, trihexyphenidyl, and clonazepam.

Risperidone and ziprasidone are commonly used as first line drugs for the treatment of psychotic disorders and overdose with these agents is increasingly being reported. Relatively few of these reports have involved co-ingestion of multiple psychotropic agents. We report a case of overdose with risperidone, ziprasidone, valproate, trihexyphenidyl and clonazepam in a 25 years female, who recovered uneventfully with supportive management. Notwithstanding the benign outcome in this instance, age, co-ingested drugs, active metabolites and medical co-morbidity are critical issues in overdose with atypical antipsychotics. As prescription of these drugs continues to increase in developing countries, systematic studies evaluating their clinical toxicity and management are necessary. The issues associated with overdose of multiple psychotropic agents and appropriate management policies are highlighted.

ß1-Adrenergic Receptor Contains Multiple IAk and IEk Binding Epitopes That Induce T Cell Responses with Varying Degrees of Autoimmune Myocarditis in A/J Mice.

Myocarditis/dilated cardiomyopathy (DCM) patients can develop autoantibodies to various cardiac antigens and one major antigen is ß1-adrenergic receptor (ß1AR). Previous reports indicate that animals immunized with a ß1AR fragment encompassing, 197-222 amino acids for a prolonged period can develop DCM by producing autoantibodies, but existence of T cell epitopes, if any, were unknown. Using A/J mice that are highly susceptible to lymphocytic myocarditis, we have identified ß1AR 171-190, ß1AR 181-200, and ß1AR 211-230 as the major T cell epitopes that bind major histocompatibility complex class II/IAk or IEk alleles, and by creating IAk and IEk dextramers, we demonstrate that the CD4 T cell responses to be antigen-specific. Of note, all the three epitopes were found also to stimulate CD8 T cells suggesting that they can act as common epitopes for both CD4 and CD8 T cells. While, all epitopes induced only mild myocarditis, the disease-incidence was enhanced in animals immunized with all the three peptides together as a cocktail. Although, antigen-sensitized T cells produced mainly interleukin-17A, their transfer into naive animals yielded no disease. But, steering for T helper 1 response led the T cells reacting to one epitope, ß1AR 181-200 to induce severe myocarditis in naive mice. Finally, we demonstrate that all three ß1AR epitopes to be unique for T cells as none of them induced antibody responses. Conversely, animals immunized with a non-T cell activator, ß1AR 201-220, an equivalent of ß1AR 197-222, had antibodies comprising of all IgG isotypes and IgM except, IgA and IgE. Thus, identification of T cell and B cell epitopes of ß1AR may be helpful to determine ß1AR-reactive autoimmune responses in various experimental settings in A/J mice.

Autoxidation and yellowing of methyl linolenate.

The autoxidation of fatty esters of linseed oil is studied extensively, and the products formed from these reactions are identified. The mechanism suggested for autoxidation, helps to understand fat deterioration resulting in offensive odours and flavours, and to develop new antioxidants to prevent this decomposition. The oxidation following oxidative copolymerization should be investigated in order to understand and to develop new methodology to prevent yellowing. Although the yellowing of indoor oil paints could be prevented to an extent, no compound is known to completely inhibit this process nor has the cause for this yellow colouration been isolated, leaving the doors wide open for further investigation.

Localization of CD8 T cell epitope within cardiac myosin heavy chain-α334-352 that induces autoimmune myocarditis in A/J mice.

BACKGROUND: Cardiac myosin heavy chain-α (Myhc), an intracellular protein expressed in the cardiomyocytes, has been identified as a major autoantigen in cardiac autoimmunity. In our studies with Myhc334-352-induced experimental autoimmune myocarditis in A/J mice (H-2a), we discovered that Myhc334-352, supposedly a CD4 T cell epitope, also induced antigen-specific CD8 T cells that transfer disease to naive animals. METHODS AND RESULTS: In our efforts to identify the CD8 T cell determinants, we localized Myhc338-348 within the full length-Myhc334-352, leading to four key findings. (1) By acting as a dual epitope, Myhc338-348 induces both CD4 and CD8 T cell responses. (2) In a major histocompatibility complex (MHC) class I-stabilization assay, Myhc338-348 was found to bind H-2Dd-but not H-2Kk or H-2Ld-alleles. (3) The CD8 T cell response induced by Myhc338-348 was antigen-specific, as evaluated by MHC class I/H-2Dd dextramer staining. The antigen-sensitized T cells predominantly produced interferon-γ, the critical cytokine of effector cytotoxic T lymphocytes. (4) Myhc338-348 was found to induce myocarditis in immunized animals as determined by histology and magnetic resonance microscopy imaging. CONCLUSIONS: Our data provide new insights as to how different immune cells can recognize the same antigen and inflict damage through different mechanisms.

Variations in clinical estimates of tumor volume regression parameters and time factor during external radiotherapy in cancer cervix: does it mimic the linear-quadratic model of cell survival?

BACKGROUND: Tumor regression parameters and time factor during external radiotherapy (EXTRT) are of paramount importance. AIMS: To quantify the parameters of tumor regression and time factor during EXTRT in cancer cervix. SETTINGS AND DESIGN: Patients, treated solely with radiotherapy and enrolled for other prospective studies having weekly tumor regressions recorded were considered. MATERIALS AND METHODS: Seventy-seven patients received 50 Gy of EXTRT followed by intracavitary brachytherapy. Loco-regional regressions were assessed clinically and regression fraction (RF) was represented as RF=c + a 1D + a 2 D2 sub - a 3T, with c, D and T as constant, cumulative EXTRT dose and treatment time respectively. STATISTICAL ANALYSIS USED: Step wise linear regression was performed for RF. Scatter plots were fitted using linear-quadratic fit. RESULTS: Coefficients of parameters D, D2 sub and T were computed for various dose intervals, namely 0--20 Gy, 0--30 Gy, 0--40 Gy and 0--50 Gy. At 0--20 Gy and 0--30 Gy, only the coefficient of D2 was significant (P 2 sub and T turned significant (P 2 sub and T showed significance, leading to an estimate of 26 Gy for a1/a2 and 0.96 Gy/day for a3/a1. CONCLUSIONS: As with alpha/beta and gamma/alpha of post-irradiation cell survival curves, a1/a2 and a3/a1 represents the cumulative effect of various radiobiological factors influencing clinical regression of tumor during the course of EXTRT. The dynamic changes in the coefficients of D, D2 sub and T, indicate their relative importance during various phases of EXTRT.

Association of Autophagy in the Cell Death Mediated by Dihydrotestosterone in Autoreactive T Cells Independent of Antigenic Stimulation.

Gender disparity is well documented in the mouse model of experimental autoimmune encephalomyelitis (EAE) induced with proteolipid protein (PLP) 139-151, in which female, but not male, SJL mice show a chronic relapsing-remitting paralysis. Furthermore, dihydrotestosterone (DHT) has been shown to ameliorate the severity of EAE, but the underlying mechanisms of its protective effects are unclear. Using major histocompatibility complex (MHC) class II dextramers for PLP 139-151, we tested the hypothesis that DHT selectively modulates the expansion and functionalities of antigen-specific T cells. Unexpectedly, we noted that DHT induced cell death in antigen-specific, autoreactive T cells, but the effects were not selective, because both proliferating and non-proliferating cells were equally affected independent of antigenic stimulation. Furthermore, DHT-exposed PLP 139-151-specific T cells did not show any shift in cytokine production; rather, frequencies of cytokine-producing PLP-specific T cells were significantly reduced, irrespective of T helper (Th) 1, Th2, and Th17 subsets of cytokines. By evaluating cell death and autophagy pathways, we provide evidence for the induction of autophagy to be associated with cell death caused by DHT. Taken together, the data provide new insights into the role of DHT and indicate that cell death and autophagy contribute to the therapeutic effects of androgens in autoreactive T cells.

Mutations in the 5' NTR and the Non-Structural Protein 3A of the Coxsackievirus B3 Selectively Attenuate Myocarditogenicity.

The 5' non-translated region (NTR) is an important molecular determinant that controls replication and virulence of coxsackievirus B (CVB)3. Previous studies have reported many nucleotide (nt) sequence differences in the Nancy strain of the virus, including changes in the 5' NTR with varying degrees of disease severity. In our studies of CVB3-induced myocarditis, we sought to generate an infectious clone of the virus for routine in vivo experimentation. By determining the viral nt sequence, we identified three new nt substitutions in the clone that differed from the parental virus strain: C97U in the 5' NTR; a silent mutation, A4327G, in non-structural protein 2C; and C5088U (resulting in P1449L amino acid change) in non-structural protein 3A of the virus leading us to evaluate the role of these changes in the virulence properties of the virus. We noted that the disease-inducing ability of the infectious clone-derived virus in three mouse strains was restricted to pancreatitis alone, and the incidence and severity of myocarditis were significantly reduced. We then reversed the mutations by creating three new clones, representing 1) U97C; 2) G4327A and U5088C; and 3) their combination together in the third clone. The viral titers obtained from all the clones were comparable, but the virions derived from the third clone induced myocarditis comparable to that induced by wild type virus; however, the pancreatitis-inducing ability remained unaltered, suggesting that the mutations described above selectively influence myocarditogenicity. Because the accumulation of mutations during passages is a continuous process in RNA viruses, it is possible that CVB3 viruses containing such altered nts may evolve naturally, thus favoring their survival in the environment.

Versatility of using major histocompatibility complex class II dextramers for derivation and characterization of antigen-specific, autoreactive T cell hybridomas.

Antigen-specific, T cell hybridomas are useful to study the cellular, molecular and functional events, but their generation is a lengthy process. Thus, there is a need to develop robust methods to generate the hybridoma clones rapidly in a short period of time. To this end, we have demonstrated a novel approach using major histocompatibility complex (MHC) class II dextramers to generate T cell hybridomas for an autoantigen, proteolipid protein (PLP) 139-151. Using MHC class II dextramers assembled with PLP 139-151 as screening and sorting tools, we successfully obtained mono antigen-specific clones within seven to eight weeks. In conjunction with other T cell markers, dextramers permitted phenotypic characterization of hybridoma clones for their antigen specificity in a single step by flow cytometry. Importantly, we achieved successful fusions using dextramer(+) cells sorted by flow cytometry as a starting population, resulting in direct identification of multiple antigen-specific clones. Characterization of selected clones led us to identify chemokine receptor, CCR4(+) to be expressed consistently, but their cytokine-producing ability was variable. Our work provides a proof-of principle that the antigen-specific, CD4 T cell hybridoma clones can be generated directly using MHC class II dextramers. The availability of hybridoma clones that bind dextramers may serve as useful tools for various in vitro and in vivo applications.