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Biomedical subjects

Amit K Dinda

Publications and source records attributed to Amit K Dinda.

11 recordsLinked to original sources

A hexanucleotide repeat upstream of eotaxin gene promoter is associated with asthma, serum total IgE and plasma eotaxin levels.

BACKGROUND: Eotaxin (CCL11) is a small protein produced in the lungs of patients with asthma, and is a potent chemoattractant for eosinophils. AIM: To elucidate the role of eotaxin in asthma by an association study of functional and novel eotaxin polymorphisms in case-control and family-based study designs. METHODS: Eotaxin +67G/A, -384A/G and -426C/T single-nucleotide polymorphisms and a hexanucleotide (GAAGGA)(n) repeat 10.9 kb upstream of the gene were genotyped in a cohort of age, sex and ethnically matched patients with asthma (n = 235) and healthy controls (n = 239), and also in a study population of 230 families with asthma recruited from north/northwest India. Total serum IgE (TsIgE) and plasma eotaxin levels were measured using ELISA. RESULTS: +67G/A polymorphism was found to be significantly associated with asthma in case-control (p = 0.009) and family-based studies (p = 0.006). Its functional role, as it was correlated with plasma eotaxin levels (p = 0.006), was also demonstrated. Further, -384C/T single-nucleotide polymorphism was found to be significantly associated with log(10) TsIgE (p = 0.016 in case-control and p = 0.018 in families) and eotaxin levels (p = 0.007). Most interestingly, for the first time, a highly significant association of the newly studied (GAAGGA)(n) hexanucleotide repeat with asthma (p = 3x10(-6)), log(10)TsIgE (p = 0.006) and eotaxin levels (p = 0.004) was observed. G_A_C_8 was also identified as an important risk haplotype associated with high TsIgE and plasma eotaxin levels. CONCLUSIONS: This study provides further evidence that eotaxin polymorphisms are associated with the development of asthma by regulating eotaxin levels and reinforces towards the scanning of other chemokine genes present at 17q21 locus for their association with asthma and related phenotypes.

Adolescent↗

Glycyrrhizin alleviates experimental allergic asthma in mice.

Asthma is a chronic respiratory disease, the incidence of which is increasing globally. The existing therapy is inadequate and has many adverse effects. It needs a better therapeutic molecule preferably of natural origin, which has negligible or no adverse effects. In view of this, we evaluated Glycyrrhizin (GRZ), a major constituent of a plant Glycyrrhiza glabra, for its efficacy on asthmatic features in a mouse model of asthma. BALB/c mice were sensitized and challenged with ovalbumin (OVA) to develop the asthmatic features such as airway hyperresponsiveness: allergen induced airway constriction and airway hyperreactivity (AHR) to methacholine (MCh), and pulmonary inflammation. The mice were orally treated with GRZ (2.5, 5, 10 and 20 mg/kg) during or after OVA-sensitization and OVA-challenge to evaluate its protective or reversal effect, respectively on the above asthmatic features. The status of airway hyperresponsiveness was measured by monitoring specific airway conductance (SGaw) using a non-invasive method and the pulmonary inflammation was assessed by haematoxylin and eosin staining of lung sections. Several other parameters associated with asthma such as interleukin (IL)-4, IL-5 interferon-gamma (IFN-gamma), OVA-specific IgE, total IgG(2a) and cortisol were measured by ELISA. GRZ (5 mg/kg) markedly inhibited OVA-induced immediate airway constriction, AHR to MCh (p<0.01), lung inflammation, and infiltration of eosinophils in the peribronchial and perivascular areas. It prevented the reduction of IFN-gamma (p<0.02), and decreased IL-4 (p<0.05), IL-5 (p<0.05) and eosinophils (p<0.0002) in the BAL fluid. Also, it reduced OVA-specific IgE levels (p<0.01) and prevented the reduction of total IgG(2a) (p<0.01) in serum. We have also showed that it has no effect on serum cortisol levels. Our results demonstrate that GRZ alleviates asthmatic features in mice and it could be useful towards developing a better therapeutic molecule in the future.

Allergens↗

Polarized helper T cells in tubercular pleural effusion: phenotypic identity and selective recruitment.

Containment of Mycobacterium tuberculosis critically depends on orchestrated generation of Th1 cells and their selective recruitment at the pathologic sites. Understanding the mechanism involved in this process is important for defining better intervention strategies. We investigated the surface phenotype of Th1 cells and the role of chemotactic factors in their selective recruitment in tuberculosis pleural effusion and tuberculin site. Memory T cells obtained from the pleural fluid expressed a battery of homing receptors such as CD11a, CCR5 and CXCR3. Similar expression profile was noted on T cells infiltrating the tuberculin site. Expression of their respective ligands such as ICAM-1, RANTES, MIP1-alpha, Mig and IP-10 were detected at pathologic sites. In vitro assay of T cell adherence to activated human umbilical vein endothelial cells (HUVEC) expressing chemotactic ligands suggests an important role of these homing molecules in their selective trafficking. Here, we demonstrate a hierarchy of CXCR3 in effector cell adhesion to HUVEC in vitro, although CD11a and CCR5 were also observed to mediate cell adhesion in an additive fashion. Findings of the present study provide mechanistic insights into the critical events of T cell trafficking in tuberculosis and may help designing better therapeutic modalities.

Adult↗

Psoriatic nephropathy--does an entity exist?

Psoriasis is an immune-mediated chronic inflammatory disorder of the skin. Association with kidney disease has been debated for a long time. Secondary renal amyloidosis in psoriatic arthropathy and drug-induced renal lesions secondary to methotrexate or cyclosporine are accepted accompaniments of psoriasis. IgA nephropathy is also known to occur in psoriatics. We report three interesting cases of renal involvement in long-standing established psoriasis on topical therapy alone. The patients presented with hypertension, significant proteinuria, hypoalbuminemia, and dyslipidemia. Kidney biopsies revealed "mesangioproliferative glomerulonephritis with IgA nephropathy," "focal proliferative glomerulonephritis," and "membranous glomerulonephropathy." The former two had marked active urinary sediment. Patients improved on prednisolone and angiotensin-converting enzyme inhibitors. Contrary to the belief that renal involvement in psoriasis is coincidental, we propose that kidney disease may be a common accompaniment of psoriasis, which may be labeled as "psoriatic nephropathy" or "psoriatic kidney disease." The exact mechanism of this entity is yet to be elucidated.

Adult↗

Effect of composition of interpenetrating polymer network hydrogels based on poly(acrylic acid) and gelatin on tissue response: a quantitative in vivo study.

The local tissue response of the biomaterial is the most important criteria for determination of its biocompatibility. In the present study, full and semi-interpenetrating polymer networks (IPN) based on polyacrylic acid (AAc) and gelatin (Ge) crosslinked with 0.5 mol % N,N'-methylene bisacrylamide (BAm) and 4% glutaraldehyde (GA), respectively, were evaluated for tissue response in rats. IPNs with varying ratios of AAc and Ge were implanted subcutaneously in rats. Gentamicin sulfate (GS)-loaded IPN samples were also studied to evaluate the possible therapeutic use of these polymers. The site of implantation was biopsied and processed for light microscopy (LM) with image analysis for assessment of tissue reaction at 2-, 6-, and 12-week intervals. The tissue reaction was evaluated as a function of composition and time. The degree of neutrophil, lymphocyte and macrophage infiltration, fibrosis, granuloma formation, integration with extracellular matrix, vascular proliferation, and damage of adjacent structures were assessed. Polymers with >66% crosslinked Ge (Gx) showed persistence of acute inflammatory reaction till 3 months, with marked tissue injury and fibrosis. On the other hand, high crosslinked AAc (Ax) content showed chronic inflammatory reaction with high macrophage infiltration. Macrophages took active part in phagocytosis, degradation, and removal of polymers without granuloma formation or significant giant cell reaction. The IPNs with acrylic acid and gelatin in the ratio of 1:1 showed least tissue reaction and thus appeared to be most biocompatible. The majority of the polymers showed integration with extracellular matrix and growth of capillaries in and around the polymer. The heamogram, liver and renal function tests, and histology of vital organs were all normal. GS loading showed no additional local or systemic reaction suggesting the potential usefulness of the hydrogels as carrier for drugs such as GS.

Acrylic Resins↗

Renal sinus hemangioma simulating renal mass: a diagnostic challenge.

A 47-year-old female presenting with right flank pain and renal mass on ultrasonography was evaluated for renal malignancy. Based on the CT findings and blood aspiration on repeated fine needle aspiration biopsy the patient underwent radical nephrectomy. Histopathology revealed renal sinus hemangioma with normal kidney, perirenal fat and the hilar structures.

Diagnosis, Differential↗

Expression of biomarkers modulating prostate cancer angiogenesis: differential expression of annexin II in prostate carcinomas from India and USA.

BACKGROUND: Prostate cancer (PCa) incidences vary with genetic, geographical and ethnic dietary background of patients while angiogenesis is modulated through exquisite interplay of tumor-stromal interactions of biological macromolecules. We hypothesized that comprehensive analysis of four biomarkers modulating angiogenesis in PCa progression in two diverse populations might explain the variance in the incidence rates. RESULTS: Immunohistochemical analysis of 42 PCa biopsies reveals that though Anx-II expression is lost in both the Indian and American population with Gleason scores (GS) ranging between 6 and 10, up to 25 % of cells in the entire high grade (GS > 8) PD PCa samples from US show intense focal membrane staining for Anx-II unlike similarly graded specimens from India. Consistent with this observation, the prostate cancer cell lines PC-3, DU-145 and MDA PCa 2A, but not LNCaP-R, LNCAP-UR or MDA PCa 2B cell lines, express Anx-II. Transcriptional reactivation of Anx-II gene with Aza-dC could not entirely account for loss of Anx-II protein in primary PCa. Cyclooxygenase-2 (COX-2) was moderately expressed in most of high grade PIN and some MD PCa and surrounding stroma. COX-2 was not expressed in PD PCa (GS approximately 7-10), while adjacent smooth muscles cells stained weakly positive. Decorin expression was observed only in high grade PIN but not in any of the prostate cancers, atrophy or BPH while stromal areas of BPH stained intensively for DCN and decreased with advancing stages of PCa. Versican expression was weak in most of the MD PCa, moderate in all of BPH, moderately focal in PD PC, weak and focal in PIN, atrophy and adjacent stroma. CONCLUSIONS: Expression of pro- and anti-angiogenic modulators changes with stage of PCa but correlates with angiogenic status. Focal membrane staining of Anx-II reappears in high grade PCa specimens only from US indicating differential expression of Anx-II. COX-2 stained stronger in American specimens compared to Indian specimens. The sequential expression of DCN and VCN in progressive stages was similar in specimens from India and USA indicating no population-based differences. The mechanistic and regulatory role of Anx-II in PCa progression warrants further investigation.

Annexin A2↗

Renal and systemic amyloidosis in systemic lupus erythematosus.

A young male presented with oral ulceration for two years; swelling face and feet of seven days duration; diffuse goiter without signs of thyroid disease; normocytic normochromic anemia, thrombocytopenia, deranged renal functions, albuminuria of 2.5 g/24h with active urinary sediment. ANA and anti-ds DNA were positive, sonography of abdomen suggested medical renal disease. Testing for HIV, HBV, VDRL, CRP, rheumatoid factor, p-ANCA and c-ANCA were negative. Thyroid hormone assays were normal. Kidney biopsy done to stage lupus nephritis did not show any evidence of lupus involvement but staining for SAA amyloid was positive. Subsequent biopsies from the liver and rectum also stained positive for amyloid. Diagnosis of "Systemic lupus erythematosus with renal and systemic secondary amyloidosis with euthyroid diffuse goiter" was made. The case is being reported and discussed because of the interesting and rare association between amyloidosis and systemic lupus erythematosus.

Adult↗

Prognostic significance of p53 nuclear overexpression in patients of muscle invasive urinary bladder carcinoma treated with cystectomy.

INTRODUCTION: The objective of the study was to determine the pattern of p53 expression in patients with muscle invasive bladder cancer treated with cystectomy and to assess the prognostic value of p53 expression in this group of patients. MATERIALS AND METHODS: We retrospectively analyzed data of 100 patients who underwent cystectomy for invasive transitional cell carcinoma of the urinary bladder. These patients were seen at 3-monthly intervals during the first 2 years, 6-monthly in the third year, and yearly thereafter. Immunohistochemical analysis for p53 was done on paraffin-fixed tissues with DO-7 antibodies. The tumours with >30% cells staining for p53 proteins were considered p53 positive. RESULTS: There were 95 males and 5 females with a mean age of 54 years. Two patients died in the perioperative period and were excluded from analysis. Over a median follow-up period of 2 years (range 3 months to 10 years) 62 patients are alive without disease while 36 had relapse and of these, 31 have died. The p53 expression was significantly related to stage and grade of the tumour. p53-negative tumours were more likely to be organ confined and of lower grade as compared to p53-positive tumours. The stage of tumour was significantly related to outcome but grade and p53 immunohistochemistry did not provide any prognostic information. CONCLUSIONS: p53 immunostaining was positive in 57% of muscle invasive urinary bladder tumours. The p53 positivity correlated well with the stage and grade of the disease, whereas it has no additional prognostic value.

Adult↗

Multiple myeloma presenting as collapsing glomerulopathy.

A 54 year old male patient was admitted with advanced renal failure of recent onset. Serology was noncontributory. Renal biopsy showed collapsing glomerulopathy with interstitial fibrosis. Bone marrow examination confirmed the diagnosis of multiple myeloma. With chemotherapy multiple myeloma went into remission. However he continued to remain dialysis dependent and a repeat kidney biopsy showed progression to endstage renal disease.

Glomerulosclerosis, Focal Segmental↗