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Biomedical subjects

D Dubey

Publications and source records attributed to D Dubey.

25 records · Page 2Linked to original sources
PubMed1979

The influence of the psyche and the brain on immunity and disease susceptibility: a critical review.

In critically reviewing the sources of evidence connecting psyche and brain with the immune system, the authors include a brief review of current knowledge of the immune system, its interactions with the neuroendocrine system, and other factors influencing its regulation. These include developmental stages, aging, rhythmicity, and a variety of exogenous influences. The need for developing further information about normal base lines is emphasized. Against that background, many sources of data demonstrating connections between the central nervous system and the immune system are presented: indirect evidence from clinical and experimental illnesses involving the immune system, and direct changes in either humoral or cellular immunity after natural or experimental stress, conditioning, hypnosis, and direct brain stimulation. Possible mechanisms are discussed, as well as some important methodological issues for further research.

Age Factors↗
PubMed1979

B lymphocyte determinants in immunoglobulin A nephropathy.

Because of our prior demonstration of a strong association betwen a specific B lymphocyte determinant and the occurrence of chronic membranoproliferative glomerulonephritis and the demonstration by others of the frequent concurrence of an IgA deposit disease, anaphylactoid purpura nephritis,with HLA-BW35, we conducted an investigation of the association among Minnesota Caucasians of the HLA markers BW35, DW1 and B lymphocyte determinants identified by three alloantisera with IgA nephropathy and the syndrome of recurrent macroscopic hematuria. The highly significant association between HLA-BW35, DW1, and B cell antigens identified by alloantisera L, B, and F, present in 50 normal Minnesota Caucasians, was not observed in 18 Minnesota patients with IgA nephropathy. The frequency of HLA-DW1 was the same among controls and patients, whereas the relative risk of developing IgA nephropathy was demonstrated to be increased 4- to 5-fold in the presence of the B cell antigens identified by alloantisera L and B. These sera appear to identify determinants on B lymphocytes associated with the disease state and possibly not intimately related to the HLA-D region. These findings emphasize the possible informativeness of defining B cell alloantisera on disease panels.

Antilymphocyte Serum↗
PubMedDate not supplied

Stones associated renal pelvic malignancies.

BACKGROUND: The clinico-pathological characteristics of renal pelvic malignancies associated with stones were retrospectively analyzed. AIMS: The main objective was to define the biological behavior and prognostic factors for these malignancies. SETTINGS & DESIGN: The tumors were classified according to the pathological types. The clinical data, imaging features and pathological features were analyzed with relation to prognosis. MATERIAL AND METHODS: Eighteen cases of malignancies associated with stone disease were retrospectively studied. The institute review board permitted the study. RESULTS: High incidence (15/18) of squamous cell carcinoma (SCC) was noted. The prognosis in this group of patients was uniformly poor. The median survival time was 3.6 months in the SCC group, 7.5 months in the Transitional Cell Carcinoma (TCC) group and 24 months in the Adenocarcinoma (AC) group. Infectious and systemic symptoms were noted in the majority of the patients. Preoperative Imaging techniques revealed tumor in only 2 cases. Both underwent radical extirpation and the median survival is 18 months till date. In the other 16 patients, where the initial diagnosis was made only on histological analysis of incomplete nephrectomy specimens, the survival was 3.56 months. All patients had prolonged history of staghorn stone disease with associated non-functioning kidney. We found that the main prognostic factor was the stage of the disease. CONCLUSIONS: Malignancies associated with stone disease have insidious onset of clinical symptoms and need a high degree of suspicion to identify them pre-operatively. The grave prognosis associated with incomplete excision makes it imperative to diagnose them earlier.

Adenocarcinoma↗
PubMedDate not supplied

Correlation of radiological and clinical features of metanephric neoplasms in adults.

The main objective was to determine the clinical and radiological features of metanephric neoplasms. The tumors were diagnosed on histopathological examination. The clinical data and imaging features were retrospectively analyzed. Between 1998 and 2003, 3 patients underwent radical nephrectomy for renal masses turning out as metanephric neoplasms on histopathology. Two of these tumors were metanephric adenoma (MA) and one was metanephric adenofibroma (MAF). Clinical and radiological features were reviewed. All patients were adult females who presented with flank pain. Tumor was detected on screening ultrasound as a hyperechoic lesion. In all cases CT showed a hyper-attenuating exophytic lesion with cystic areas that enhanced with IV contrast. Based on combination of clinical and imaging features it may be possible to prospectively identify metanephric neoplasms and thus avoid unnecessary radical nephrectomy in favor of conservative surgery.

Adenofibroma↗
PubMedDate not supplied

Prognosticfactors in patients with renal cell carcinoma: is TNM (1997) staging relevant in Indian subpopulation?

BACKGROUND: RCC (Renal Cell Carcinoma) is a common genitourinary malignancy, but its behavior has not been studied in the Indian Subpopulation. AIMS: The aim of this study was to assess the validity of 1997 AJCC TNM staging in Indian subpopulation and also to identify independent predictors for survival in patients having RCC. SETTING AND DESIGN: Retrospective uncontrolled analysis of patients with RCC was performed at our centre. MATERIAL AND METHODS: Medical records of patients of undergoing radical nephrectomy at our center between 1994 to August 2003 were identified retrospectively. Medical records of 178 patients were available for analysis. Patient characteristics, preoperative imaging and surgical details were reviewed. Each tumor was staged according to the 1997 AJCC TNM classification. Nuclear grade was assigned according to the Fuhrman's grading system. STATISTICAL METHODS: Statistical analysis was performed using statistical software and descriptive statistics and survival functions were obtained. Univariate and multivariate analysis of factors affecting outcome of the patient were performed. RESULTS: Mean follow up period was 42.3 months (range 3 to 108 months). Stage wise 5-year Cancer specific survival was 87.2% in stage 1 disease, 74.3% in stage 2, 36.4% in stage 3 and 3.1% in stage 4. Univariate analysis revealed that stage, grade and lymph node status were statistically significant (P=0.009, 0.007 and 0.003 respectively). Sub-classifying stage 1 tumors between tumor of less than 4 cm. and more than 4 cm. did not reveal any statistically significant difference in survival (P=0.32). Multivariate analysis model revealed that Fuhrman's grade and lymph node status were statistically significant (P=0.007 and 0.002 respectively). CONCLUSION: This study validates the TNM (1997) staging for RCC as having significant survival impact in the Indian subpopulation. Sub-classifying stage 1 tumors between tumor of less than 4 cm. and more than 4 cm is not of much importance. Nuclear grade and lymph node involvement are important independent predictors of survival. Organ confined tumors with high nuclear grades need to be followed up more rigorously.

Adult↗
PubMedDate not supplied

Localization and treatment of an oxidation-sensitive defect within the TCR-coupled signalling pathway that is associated with normal and premature immunologic aging.

The age-dependent decline in the ability of T-cells to mount a proliferative response both to mitogens and to receptor ligation is due to an age-related defect in signal transduction, since functional expression of receptors displayed by aged T-cells is not reduced. We show here that, although turnover of phosphatidylinositol is not diminished, total inositol-trisphosphate generation decreases after T-cell receptor (TCR) ligation, resulting in reduced flux of calcium. Defective inositol-trisphosphate generation may result from impaired activation of phospholipase C due to decreased tyrosine phosphorylation of this enzyme after ligation of CD3 in aged cells. Proliferation of aged T-cells, which is normally 10-30% of the level of young controls, was enhanced almost tenfold by glutathione or its precursor N-acetyl L-cysteine (NAC), reached levels of young controls and was accompanied by restoration of normal inositol-trisphosphate generation and calcium flux. These findings suggest that the T-cell antigen receptor is associated with at least two types of signal transduction modules. The first depends on synthesis and phosphorylation of phosphatidylinositol that is independent of sulphydryl groups and is not affected by senescence. The second transduction module includes tyrosine phosphorylation and activation of phospholipase C. This module is regulated by glutathione levels and is diminished in aged T-cells, that are deficient in reducing equivalents which support the PLC gamma-dependent generation of inositol-trisphosphate from phosphatidylinositol derivatives. This underlying biochemical defect also occurs earlier in strains which display premature aging due to differences in the H-2 region of MHC I.

Aging, Premature↗