Role Of Prior Immunity in binding to Spike of "Future" Omicron Subvariants.

BACKGROUND: Throughout the COVID-19 pandemic, virus evolution and large-scale vaccination programs have caused multiple exposures to SARS CoV-2 spike protein, resulting in complex antibody profiles. The binding of these to spike protein of "future" variants in the context of such heterogeneous exposure has not been studied. METHODS: We tested archival sera (Delta and Omicron period) stratified by anti-spike antibody (including IgG) levels for reactivity to Omicron-subvariants(BA.1, BA.2,BA.2.12.1, BA.2.75, BA.4/5 and BF.7) spike protein. Assessed antigenic distance between groups using Antigenic Cartography and performed hierarchical clustering of antibody data in a Euclidean distance framework. RESULTS: Antibody (including IgG) antibody reactivity to Wild-type (CLIA) and subvariants (ELISA) spike protein were similar between periods (p>0.05). Both 'High S' and 'Low S' of Delta and Omicron periods were closely related to "future" subvariants by Antigenic Cartography. Sera from different S groups clustered together with 'Low S' interspersed between 'High S' on hierarchical clustering, suggesting common binding sites. Further, anti-spike antibodies (including IgG) to Wild-type (S1/S2 and Trimeric S) clustered with Omicron-subvariant binding antibodies. CONCLUSIONS: Hybrid immunity caused by cumulative virus exposure in Delta or Omicron periods resulted in equivalent binding to "future" variants, which might be due to binding to conserved regions of spike protein of future variants. A prominent finding is that the 'Low S' antibody demonstrates similar binding.

Assessment of serum biotin levels and its association with blood glucose in gestational diabetes mellitus.

Aim: The incidence of gestational diabetes mellitus is increasing worldwide. Biotin is shown to improve glycemic status in diabetes mellitus. We wanted to study whether there is a difference in biotin levels between mothers with and without gestational diabetes mellitus (GDM), association of biotin with blood glucose, and with the outcome of GDM. Methods: We recruited 27 pregnant mothers with GDM and 27 pregnant mothers without GDM. We measured the biotin levels using enzyme linked immunosorbent assay (ELISA). We measured the blood glucose during OGTT and fasting insulin levels in the study participants. Results: We found that biotin levels were slightly decreased in mothers with GDM [271 (250,335)] as compared to control mothers [309 (261,419)], though it was not statistically significant (p = 0.14). Blood glucose levels were found to be significantly higher in GDM mothers as compared to control mothers during fasting, 1 h and 2 h plasma sample obtained during OGTT. Biotin was not significantly associated with blood glucose in pregnant mothers. Logistic regression analysis showed that biotin (OR = 0.99, 95 % CI = 0.99-1.00) has no association with the outcome of GDM. Conclusion: Ours is the first study to compare the biotin levels in GDM mothers and control mothers. We found that the biotin levels were not significantly altered in GDM mothers as compared to control mothers and biotin levels have no association with the outcome of GDM.

Comprehensive evaluation of patterns of hypoglycemia unawareness (HUA) and glycemic variability (GV) in patients with fibrocalculous pancreatic diabetes (FCPD): A cross-sectional study from South India.

OBJECTIVES: Hypoglycemia unawareness (HUA) in patients with FCPD is common with an unclear etiology. We evaluated the prevalence, characteristics of HUA, glycemic variability (GV), its possible association with pancreatic glucagon secretion & cardiac autonomic function in patients with FCPD. METHODS: A two-week ambulatory glucose profile (AGP) and cardiac autonomic function test was done in patients with FCPD (n = 60), and categorized into UNAWARE (n = 44) and AWARE (n = 16) groups based on the Hypoglycemia Unawareness Index (HUI) score. Glycaemic variability was assessed from the AGP data using Easy GV 9.0.2 software. A subset of patients from both the groups (n = 11) underwent a mixed-meal challenge test and were compared with healthy individuals (controls; n = 11). RESULTS: HUA was evidenced in 73% (44/60) of patients with FCPD. Significant hypoglycemia, nocturnal hypoglycemia, duration of hypoglycemia and poor cardiac autonomic functions (p = 0.01) were prominent in the UNAWARE group. The overall GV was greater in the UNAWARE group. In the UNAWARE group, significantly reduced fasting and post prandial glucagon levels negatively correlated with HUI (r = -0.74, p < 0.05) and GV-hypoglycemia indices (p < 0.05) In contrast, significantly higher post prandial glucagon levels in the AWARE group positively correlated with post prandial hyperglycemia (r = 0.61, p < 0.05). CONCLUSION: Heterogeneity in patterns of glucagon secretion were significantly associated with HUA and GV. Reduced glucagon levels contribute to greater risks of HUA, nocturnal hypoglycemia and greater GV, while hyperglucagonemia predisposes to postprandial hyperglycemia and hypoglycemia awareness in patients with FCPD.

Salivary free light chains and salivary immunoglobulins as potential non-invasive biomarkers in primary Sjögren's syndrome.

BACKGROUND: B cells contribute significantly to the pathogenesis of primary Sjögren's syndrome (pSS). Free light chains (FLCs) are generated during the production of immunoglobulins (Igs) and are surrogates of B cell activity. We hypothesized that salivary FLCs and salivary Igs could represent salivary gland inflammation and therefore, serve as biomarkers in pSS. METHODS: Patients >18 years old fulfilling the American College of Rheumatology / European League Against Rheumatism (EULAR) 2016 criteria for pSS and age-matched healthy and disease controls (sicca non-pSS, rheumatoid arthritis, systemic lupus erythematosus) were recruited for this cross-sectional study. FLCs in saliva and serum were measured by immunoturbidimetry. Serum and salivary Igs were measured by nephelometry and enzyme-linked immunosorbent assay, respectively. Area under the receiver operator characteristic curve was determined. The factors influencing the serum and salivary FLCs in pSS were determined using backward linear regression. RESULTS: A total of 78 patients with pSS, 76 healthy controls and 62 disease controls were recruited. Median EULAR SS disease activity index (interquartile range) was 1 (3.75). Serum FLCκ and FLCλ, salivary FLCλ, serum and salivary IgG, salivary IgM was significantly higher in the pSS group compared to the controls. Areas under the curve for salivary FLCλ, serum FLCκ, serum and salivary IgG were 0.75, 0.72, 0.78 and 0.77, respectively. Regression analysis showed that salivary FLCκ, salivary FLCλ and salivary IgG were associated with positive salivary gland histopathology. Use of immunosuppressants and glucocorticoids was associated with lower values of salivary parameters. CONCLUSION: Salivary FLCλ and salivary IgG were significantly different between pSS and control groups and could be potential non-invasive biomarkers in pSS. These findings should be confirmed in larger longitudinal studies.

Association between head circumference at two years and second and fifth year cognition.

BACKGROUND: Head circumference (HC) measurement is routinely not performed in early childhood and there is conflicting information about its utility in literature. The current study analyses the association between HC at two years of age and cognition at two and five years of age. METHODS: A community based birth-cohort recruited between 2010 and 2012 was followed up till five years of age in an urban slum in Vellore, India. Children were recruited at birth after informed parental consent by consecutive sampling using eligibility criteria of healthy new-born, singleton pregnancy and family's availability in the study area during follow-up. HC measured at two years of age was used as the exposure variable to calculate association with cognition at both two and five years of age. Cognitive domain of Bayley scale of infant development was used at two years of age and Wechsler Preschool Primary Scales of Intelligence at five years. RESULTS: Of the 251 enrolled children, 138 (55%) were girls and 71 (30%) belonged to lower socioeconomic status. At 2 years, 8.81% of children had HC < - 3SD. Compared to children with HC z-scores ≥ - 2 SD, those with measurements < - 3 SD had a lower cognition scores by - 2.21 [95% CI: - 3.87 - -0.56] at 2 years. Also, children with HC < - 3 SD at two years scored significantly lower scores in cognitive domains of verbal, - 7.35 [95% CI: - 11.78 - -2.92] and performance, - 7.07 [95% CI: - 11.77 - -2.36] intelligence at five years. CONCLUSIONS: This study showed that smaller HC at 2 years of age was negatively associated with cognition at both 2 and 5 years of age. Early childhood HC measurements can be utilised as a cheaper screening tool to identify children at risk in LMIC settings. Further studies can confirm these findings in diverse settings.

Platelet-Lymphocyte Ratio as a Novel Surrogate Marker to Differentiate Thyrotoxic Patients with Graves Disease from Subacute Thyroiditis: a Cross-Sectional Study from South India.

OBJECTIVE: Graves disease (GD) and the toxic phase of subacute thyroiditis (SAT) have similar clinical and biochemical presentations, and differentiating them requires sophisticated investigations. Since thyroid hormones have been noted to affect all hematologic cell lines, we have used the platelet lymphocyte ratio (PLR)-an index usually utilized in inflammatory or malignant disorders-to compare patients with and without thyrotoxicosis and to analyze its use in distinguishing between patients with GD and SAT prior to therapy. METHODS: This was a cross-sectional study conducted in the Department of Endocrinology, Christian Medical College, Vellore, India. During the study period, 800 patients with features of thyrotoxicosis visited the outpatient clinic. Those who had thyroid radioiodine (131I) uptake (RAIU) study and complete blood count (CBC) at diagnosis were included (N = 500). Based on the RAIU values, these were divided as GD (n = 354) and SAT (n = 146). Baseline characteristics, thyroid function tests, and components of the CBC and PLR were obtained. The data were compared with a group of 250 matched euthyroid controls. Analyses were performed using SPSS version 21.0 software. RESULTS: PLR showed significant reductions in both GD and SAT patients when compared to euthyroid controls (P = .01), with greater reductions seen in GD than SAT (74.5 ± 19 vs. 84.4 ± 26; P = .01). Using receiver operating characteristic analysis of PLR, an optimal PLR cut-off of 70.4 was found to differentiate GD from SAT with a sensitivity of 86% and specificity of 74%. CONCLUSION: PLR can be used as a novel surrogate marker to differentiate between patients with GD and SAT prior to therapy, especially in resource-limited settings.

Expression of Metallothionein after Administration of Aspirin, Vitamin C or Zinc Supplement in the DMH Induced Colon Carcinoma in Rat

Background: Chemoprevention refers to the use of specificnatural or synthetic chemical agents to suppress the development and progression to carcinoma. The purpose of this study was to assess the effect of aspirin, vitamin C or zinc on the metallothionein (MT) mRNA gene expression as well as MT protein content byimmunohistochemistry andradioimmunoassay (RIA) in 1, 2-dimethyl hydrazine (DMH) induced cancerous colonic tissuein rats. Methods: Rats were randomly divided into three groups, group 1 (aspirin), group 2 (vitamin C) group 3 (zinc), each of which was further sub divided into two groups and given subcutaneous injections of DMH (30 mg/kg body weight) twice a week for 3 months and sacrificed at either 4 months (A-precancer model) or at 6 months (B-cancer model).The control groups were administered 0.5 ml saline subcutaneously. All the 3 groups were simultaneouslyadministered aspirin, vitamin Cor zinc supplement respectively from the beginning till the end of the study. Results: It was observed that rats co-treated with aspirin, vitamin C or zinc resulted in a significant increase in the colonic MT mRNA expression in the precancer and cancer model as compared to the saline only controls. MT protein expression showed a 60%, 64% and 78% immunopositivity in the co-treated groups respectively.The mean MT content in the precancer and the cancer model was restored to near normal levels in all the three co-treated groups. Conclusion: These results suggest that co-administration of aspirin, vitamin C or zinc resulted in a significant increase in MT mRNA gene expression, MT protein expression and MT protein content which could possibly be one of the reasons for a chemo protective effect against progression to colonic cancer in a chemically induced DMH model in rat.Zinc supplement had a greater effect on metallothionein expression than aspirin or vitamin C.

Arsenite Effects on Mitochondrial Bioenergetics in Human and Mouse Primary Hepatocytes Follow a Nonlinear Dose Response.

Arsenite is a known carcinogen and its exposure has been implicated in a variety of noncarcinogenic health concerns. Increased oxidative stress is thought to be the primary cause of arsenite toxicity and the toxic effect is thought to be linear with detrimental effects reported at all concentrations of arsenite. But the paradigm of linear dose response in arsenite toxicity is shifting. In the present study we demonstrate that arsenite effects on mitochondrial respiration in primary hepatocytes follow a nonlinear dose response. In vitro exposure of primary hepatocytes to an environmentally relevant, moderate level of arsenite results in increased oxidant production that appears to arise from changes in the expression and activity of respiratory Complex I of the mitochondrial proton circuit. In primary hepatocytes the excess oxidant production appears to elicit adaptive responses that promote resistance to oxidative stress and a propensity to increased proliferation. Taken together, these results suggest a nonlinear dose-response characteristic of arsenite with low-dose arsenite promoting adaptive responses in a process known as mitohormesis, with transient increase in ROS levels acting as transducers of arsenite-induced mitohormesis.

Diagnostic accuracy of salivary and serum-free light chain assays in primary Sjögren's syndrome: a pilot study.

OBJECTIVE: To estimate levels of salivary and serum free light chains (FLCs) and explore its utility as a biomarker in primary Sjögren's syndrome (pSS). METHODS: Patients with pSS classified by American European Consensus group 2002 or American College of Rheumatology 2012 criteria between January 2015 and August 2015 were included. Healthy staff and non-first degree relatives of patients constituted controls. Serum and salivary FLCs were measured by immunoturbidometry using FREELITE™ Human Kappa(κ) and Lambda(λ) Free Kit (Binding site, Birmingham, UK), on a Roche Modular P800. FLCs were compared between cases and controls using the Mann-Whitney U-test. The receiver operator characteristic curve was constructed to analyze the discriminating ability of salivary and serum kappa and lambda FLCs. RESULTS: Salivary and serum FLCs were assayed in 15 patients and 13 patients, respectively, and in 15 controls. Median age of cases and controls was 34 years. Salivary kappa and lambda FLCs were higher in pSS as compared to controls (P < 0.05 and P < 0.001, respectively). Serum kappa and lambda FLCs were also higher in pSS (both P < 0.05). Salivary lambda levels were higher in pSS with ocular signs; serum kappa and lambda levels were higher in those with ocular symptoms. A cut off of ≥ 1.1 mg/L for salivary lambda FLC had a sensitivity and specificity of 73.3% and 93.3%, respectively, for the diagnosis of pSS. Serum kappa FLC ≥ 30 mg/L had a sensitivity and specificity of 92.3% and 73.3%, respectively. CONCLUSION: Serum and salivary FLCs and in particular the latter, are potential biomarkers in pSS. Larger studies are required for validating the findings.

Arsenicosis, possibly from contaminated groundwater, associated with noncirrhotic intrahepatic portal hypertension.

BACKGROUND AND AIMS: Idiopathic noncirrhotic intrahepatic portal hypertension (NCIPH), a chronic microangiopathy of the liver caused by arsenicosis from use of contaminated groundwater, was reported from Asia. This study aimed to see, if in the twenty-first century, arsenicosis was present in NCIPH patients at our hospital and, if present, to look for groundwater contamination by arsenic in their residential locality. METHODS: Twenty-seven liver biopsy proven NCIPH patients, 25 portal hypertensive controls with hepatitis B or C related cirrhosis and 25 healthy controls, matched for residential locality, were studied. Eighty-four percent to 96 % of study subjects belonged to middle or lower socioeconomic category. Arsenicosis was looked for by estimation of arsenic levels in finger/toe nails and by skin examination. Arsenic levels in nails and in ground water (in NCIPH patients with arsenicosis) was estimated by mass spectrometry. RESULTS: Nail arsenic levels were raised in five (10 %) portal hypertensive study subjects [two NCIPH patients (both had skin arsenicosis) and three portal hypertensive controls]. All of these five patients were residents of West Bengal or Bangladesh. Skin arsenicosis was noted in three NCIPH patients (11 %) compared to none of disease/healthy controls. Ground water from residential locality of one NCIPH patient with arsenicosis (from Bangladesh) showed extremely high level of arsenic (79.5 µg/L). CONCLUSIONS: Arsenicosis and microangiopathy of liver, possibly caused by environmental contamination continues in parts of Asia. Further studies are needed to understand the mechanisms of such 'poverty-linked thrombophilia'.

Expression of metallothionein in dimethylhydrazine-induced colonic precancerous and cancerous model in rat.

AIM: Metallothionein (MT) is a small protein with a high affinity for divalent heavy metals and has a function in zinc homeostasis. The purpose of this study was to assess the MT mRNA gene expression as well as the MT protein content by immunohistochemistry and radioimmunoassay (RIA) in 1,2-dimethylhydrazine (DMH)-induced precancerous and cancerous colonic tissue in rats. MATERIALS AND METHODS: Six-week-old rats were given subcutaneous injections of DMH twice a week for 3 months and sacrificed at 4 months (precancerous model) and 6 months (cancerous model). We determined MT mRNA expression by reverse transcription polymerase chain reaction and MT protein content by both immunohistochemical expression and cadmium-109 RIA. RESULTS: MT mRNA expression in the large intestine showed statistically significant decrease in the precancerous (P < 0.01) and the cancerous (P < 0.001) model as compared with controls. Immunohistochemical expression of MT showed statistically significant decrease (P < 0.05) in the colonic cancerous tissue. MT content in the large intestine showed statistically significant decrease in precancerous (P < 0.005) and cancerous (P < 0.001) model as compared with controls. CONCLUSION: This study suggests that a decrease in the colonic MT mRNA expression, MT protein expression, and content in DMH-induced colonic cancer model is associated with the development of preneoplastic lesions and further progression to carcinoma in the colon results in a greater reduction in the levels of each of these parameters.

Protective role of aspirin, vitamin C, and zinc and their effects on zinc status in the DMH-induced colon carcinoma model.

Chemoprotection refers to the use of specific natural or synthetic chemical agents to suppress or prevent the progression to cancer. The purpose of this study is to assess the protective effect of aspirin, vitamin C or zinc in a dimethyl hydrazine (DMH) colon carcinoma model in rats and to investigate the effect of these supplements on changes associated with colonic zinc status. Rats were randomly divided into three groups, group 1 (aspirin), group 2 (vitamin C) and group 3 (zinc), each being subdivided into two groups and given subcutaneous injection of DMH (30 mg/kg body wt) twice a week for 3 months and sacrificed at 4 months (A-precancer model) and 6 months (B-cancer model). Groups 1, 2, 3 were simultaneously given aspirin, vitamin C, or zinc supplement respectively from the beginning till the end of the study. It was observed that 87.5% of rats co-treated with aspirin or vitamin C showed normal colonic histology, along with a significant decrease in colonic tissue zinc at both time points. Rats co-treated with zinc showed 100% reduction in tumor incidence with no significant change in colonic tissue zinc. Plasma zinc, colonic CuZnSOD (copper-zinc superoxide dismutase) and alkaline phosphatase activity showed no significant changes in all 3 cotreated groups. These results suggest that aspirin, vitamin C or zinc given separately, exert a chemoprotective effect against chemically induced DMH colonic preneoplastic progression and colonic carcinogenesis in rats. The inhibitory effects are associated with maintaining the colonic tissue zinc levels and zinc enzymes at near normal without significant changes.

Zinc and zinc related enzymes in precancerous and cancerous tissue in the colon of dimethyl hydrazine treated rats.

Trace element zinc deficiency or excess is implicated in the development or progression of some cancers. The exact role of zinc in the etiology of colon cancer is unclear. To cast light on this question, an experimental model of colon carcinogenesis was applied here. Six week old rats were given sub cutaneous injections of DMH (30 mg/kg body weight) twice a week for three months and sacrificed after 4 months (precancer model) and 6 months (cancer model). Plasma zinc levels showed a significant decrease (p<0.05) at 4 months and a greater significant decrease at 6 months (p<0.01) as compared with controls. In the large intestine there was a significant decrease in tissue zinc levels (p<0.005) and in CuZnSOD, and alkaline phosphatase activity (p<0.05) in the pre-cancerous model and a greater significant decrease in tissue zinc (p<0.0001), and in CuZnSOD and alkaline phosphatase activity (p<0.001), in the carcinoma model. The tissue zinc levels showed a significant decrease in the small intestine and stomach (p<0.005) and in liver (p<0.05) in the cancer model. 87% of the rats in the precancer group and 92% rats in the cancer group showed histological evidence of precancerous lesions and carcinomas respectively in the colon mucosa. This study suggests that the decrease in plasma zinc, tissue zinc and activity of zinc related enzymes are associated with the development of preneoplastic lesions and these biochemical parameters further decrease with progression to carcinoma in the colon.

Zinc status of patients with benign prostatic hyperplasia and prostate carcinoma.

OBJECTIVES: The exact cause of benign prostatic hyperplasia (BPH) and prostatic carcinoma is unknown. Changes in the level of the trace element zinc (Zn) are known to be associated with the functioning of different organs (breast, colon, stomach, liver, kidney, prostate, and muscle). This study is aimed at estimating and comparing the zinc levels in the prostate tissue, plasma, and urine obtained from patients diagnosed with BPH or prostatic carcinoma. MATERIALS AND METHODS: The prostate tissue zinc, plasma zinc, and urine zinc/creatinine ratio in BPH, prostate cancer, and normal subjects were measured by atomic absorption spectrophotometry. RESULTS: In prostate carcinoma, the mean tissue zinc was decreased by 83% as compared to normal tissue and in BPH, there was a 61% decrease in mean tissue zinc as compared to normal tissues. Both these values were statistically significant. The plasma zinc in prostate cancer patients showed a 27% decrease (P < 0.01) as compared to controls and 18% decrease (P < 0.01) as compared to BPH. The urine zinc/creatinine (ratio) was significantly increased to 53% in prostate cancer patients, and a 20% significant increase was observed in BPH as compared to normal subjects. CONCLUSIONS: It is evident from this study that BPH or prostate carcinoma may be associated with a reduction in the levels of tissue zinc, plasma zinc, and an increase in urine zinc/creatinine.

Unsymmetrical DMH - an isomer of 1,2 DMH - is it potent to induce gastrointestinal carcinoma in rats?

Very few animal studies have used 1,1-dimethyl hydrazine (unsymmetrical dimethyl hydrazine - UDMH) as a carcinogen. This study was designed to investigate the carcinogenicity of UDMH in the gastrointestinal tract in a rat model. We wanted to observe if there were any changes in tissue zinc levels and tissue copper zinc superoxide dismutase (CuZnSOD) enzyme activity during the carcinogenic process, and to compare these values with those of control rats in the medium- and long-term. Six-week-old Wistar rats were given a subcutaneous injection of UDMH (30mg/kg body wt) twice a week for 20 weeks, and sacrificed after 5 and 9 months of treatment. Tissue zinc levels showed a significant decrease (p<0.05) in the large intestine at 9 months, whereas in the stomach and small intestine there were no significant changes at 5 and 9 months. Tissue CuZnSOD enzyme activity in the stomach, small intestine and large intestine showed no significant decrease at 5 and 9 months as compared to controls. Histologically, the large intestine was normal at 9 months. This study suggests that UDMH administered at the above dosage was not carcinogenic in this model.

Tissue zinc levels in precancerous tissue in the gastrointestinal tract of azoxymethane (AOM)-treated rats.

Alterations in tissue zinc levels have been documented in patients with gastrointestinal tract malignancies and more frequently, in those with colonic cancer. However, the precise role of tissue zinc in carcinogenesis is not well elucidated. This study, using a well-established colon cancer model in rats, was designed to investigate the relationship of tissue zinc to the carcinogenic process. The aim was to examine tissue zinc levels in the preneoplastic tissues and to study the changes that occur during transition of mucosa from normal to preneoplastic state. Six-week old rats were given a single dose subcutaneous injection of azoxymethane (AOM) (30mg/kg body weight) and sacrificed after 1, 2, 5, and 9 months of the treatment. Plasma zinc levels showed a significant decrease (p<0.05) at 9 months compared with controls. Tissue zinc levels showed a significant decrease in the large intestine at 1 and 2 months (p<0.05) and at 5 and 9 months (p<0.01), in the small intestine at 2, 5, and 9 months (p<0.05), and in the stomach at 5 and 9 months (p<0.05). The maximum percent decrease (45%) in tissue zinc was observed in the large intestine at 9 months. Tissue copper zinc super oxide dismutase (CuZnSOD) activity was assessed in the body of the stomach, small intestine, and large intestine and compared with the control group. There was a significant fall in CuZnSOD levels in the small intestine at 9 months (p<0.05) and in the large intestine at 5 and 9 months (p<0.01). Two of these six rats showed histological evidence of precancerous lesions in the mucosa of the colon. This study suggests that the decrease in plasma zinc, tissue zinc and activity of CuZnSOD is associated with development of preneoplastic lesions in the colonic mucosa.