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Biomedical subjects

P Kumar

Publications and source records attributed to P Kumar.

At least 163 records · Page 9Linked to original sources
PubMed2001

M cells and associated lymphoid tissue of the equine nasopharyngeal tonsil.

The aim of this study was to characterise the morphological and histochemical features of equine nasopharyngeal tonsillar tissue. Nasal and oropharyngeal tonsillar tissue has been described as the gatekeeper to mucosal immunity because of its strategic location at the entrance to the respiratory and alimentary tracts. A combination of light, scanning and transmission electron microscopy has revealed the presence of follicle-associated epithelium (FAE) overlying lymphoid tissue of the equine nasopharyngeal tonsil caudal to the pharyngeal opening of the guttural pouch. Membranous microvillus (M) cells were identified in the FAE on the basis of short microvilli, an intimate association with lymphocytes, cytoplasmic vimentin filaments and epitopes on the apical surface reactive with lectin GS I-B4 specific for alpha-linked galactose. CD4-positive lymphocytes were scattered throughout the lamina propria mucosae as well as forming dense aggregates in the subepithelial part. The central follicular area was heavily populated with B lymphocytes and the dome and parafollicular areas contained both CD4- and CD8-positive lymphocytes. CD8-positive lymphocytes were also present in the epithelium and, together with B lymphocytes, in small numbers in the lamina propria mucosae. These observations indicate that the nasopharyngeal tonsil is potentially an important mucosal immune induction site in the horse and an appropriate target for intranasally administered vaccines.

Animals↗
PubMed2001

State-of-the-art prostate cancer treatment and research. A report from the Cancer Institute of New Jersey.

Prostate cancer is a devastating disease that will be diagnosed in approximately 200,000 men in 2001. New methods for screening, prevention, and treatment are being developed. In addition, novel agents for the treatment of resistant prostate cancer are being developed in clinical trials. This review summarizes the recent efforts in diet, screening, novel systemic therapies, and alternative medicine for prostate cancer.

Adult↗
PubMed2001

Mumps with cerebellar encephalitis.

A 30 years male patient, having typical symptoms of mumps, presented with acute cerebellar ataxia two days after the onset of parotid enlargement. The neurological symptoms showed complete recovery over the subsequent six weeks, suggestive of para-infectious cerebellar demyelination due to mumps.

Adult↗
PubMed2001

Light and electron microscope studies on the nasopharynx and nasopharyngeal tonsil of the horse.

Light and electron microscope studies were conducted on the nasopharynx and the nasopharyngeal tonsil of 15 young horses. The nasopharynx and nasopharyngeal tonsil was lined with pseudostratified columnar ciliated epithelium and goblet cells. The lymphoepithelium of the nasopharyngeal tonsil was folded forming crypts, the mucosa of which was modified into follicle associated epithelium characterized by stratified cuboidal epithelium, loss of cilia, absence of goblet cells and infiltration of lymphocytes. The lamina propria mucosae of the nasopharyngeal tonsil contained well-developed lymphoid tissue and clusters of seromucus acini. Scanning electron-microscopy revealed a dense mat of cilia covering the nasopharynx and nasopharyngeal tonsil. The follicle-associated epithelium consisted of different populations of microvillus cells in addition to M cells with very short microvilli and a few squamous and intermediate cells. Microvillus cells in the deeper part of the FAE had larger microvilli and their cytoplasm contained a dense population of mitochondria, smooth and rough endoplasmic reticulum, Golgi complexes and lysosomes. The flat surfaced M cell had a more electron-dense cytoplasm and contained small supranuclear vacuoles in addition to the organelles seen in microvillus cells.

Adenoids↗
PubMed2001

Comparative functional characterization of mouse bone marrow-derived mast cells and peritoneal mast cells in response to non-immunological stimuli.

The cultured mouse mast cells that are dependent on spleen-derived factor for their proliferation and maintenance and have been shown to be similar to mucosal mast cells in terms of their T-cell dependence and histochemical staining characteristics. Mast cell heterogeneity has been confirmed by functional characterization of mouse bone marrow-derived mast cells (MBMMC) and mouse peritoneal mast cells (MPMCs). MPMCs released around 30% of histamine when stimulated with compound 48/80 whereas MBMMC were almost unresponsive to the same stimulus. Calcium Ionophore A23187 on the other hand, released histamine in dose-dependent manner from MBMMC. The study was undertaken to investigate the effect of antiallergic drug, disodium cromoglycate (DSCG), a synthetic cromone and quercetin, a plant-derived flavonoid on Ca ionophore A23187 induced histamine release from MBMMC. MBMMCs were almost unresponsive to DSCG whereas Ca Ionophore induced histamine release was blocked by Quercetin. The results indicate that response of mast cells at one anatomic site to a given stimulus does not necessarily predict the response of mast cells at a different anatomic location to the same stimulus. It shows functional heterogeneity within a single species. So, it cannot be assumed that antiallergic compounds stabilizing mast cells in one tissue site or organ will be equally efficacious against mast cells in other sites.

Animals↗
PubMed2001

Increased hepatic VLDL secretion, lipogenesis, and SREBP-1 expression in the corpulent JCR:LA-cp rat.

The corpulent JCR:LA-cp rat (cp/cp) is a useful model for study of the metabolic consequences of obesity and hyperinsulinemia. To assess the effect of hyperinsulinemia on VLDL secretion in this model, we measured rates of secretion of VLDL in perfused livers derived from cp/cp rats and their lean littermates. Livers of cp/cp rats secreted significantly greater amounts of VLDL triglyceride and apolipoprotein, compared with lean littermates. The content of apoB, apoE, and apoCs in both perfusate and plasma VLDL was greater in the cp/cp rat, as was the apolipoprotein (apo)C, apoA-I, and apoA-IV content of plasma HDL. Triglyceride content was also greater in cp/cp livers, as was hepatic lipogenesis and expression of lipogenic enzymes and sterol regulatory element binding protein-1 (SREBP-1). Hepatic mRNAs for apoE, and apoA-I were higher in livers of cp/cp rats. In contrast, the steady state levels of apoC-II, apoC-III, and apoB mRNAs were unchanged. Thus, livers of obese hyperinsulinemic cp/cp JCR:LA-cp rats secrete a greater number of VLDL particles that are enriched in triglyceride, apoE, and apoC. Greater secretion of VLDL in the cp/cp rat in part results from higher endogenous fatty acid synthesis, which in turn may occur in response to increased expression of the lipogenic enzyme regulator SREBP-1c.

Animals↗
PubMed2001

Hepatoxic alterations induced by inhalation of trichlorethylene (TCE) in rats.

OBJECTIVE: Trichlorethylene (TCE) is one of the most potent organic unsaturated solvents being used in dry cleaning, metal degreasing, thinner for paints varnishes and electroplating, etc. and has been reported to be a hepatoxicant through oral and dermal exposure. However, its inhalation toxicity data is very limited in the literature due to the fact that the exposure levels associated with these effects were usually not reported. Hence, inhalation toxicity study was carried out for hepatotoxic studies. METHODS: Inhalation toxicity studies was carried out by exposing rats to TCE for 8, 12 and 24 weeks in a dynamically operated whole body inhalation chamber. Sham treated control rats were exposed to compressed air in the inhalation chamber for the same period. RESULTS: Significant increase in liver weight (liver enlargement) appeArance of necrotic lesion with fatty changes and marked necrosis were observed after longer duration (12 and 24 weeks) of TCE exposure. The lysosomal rupture resulted in increased activity of acid and alkaline phosphatase alongwith reduced glutathione content and total increased sulfhydryl content in liver tissue. CONCLUSION: TCE exposure. through inhalation route induces hepatotoxicity in terms of marked necrosis with fatty changes and by modulating the lysosomal enzymes.

Animals↗
PubMed2001

Pulmonary toxicity of a formulated preparation of fenvalerate in rats subchronically exposed by nose only inhalation for 90 days.

OBJECTIVE: The pulmonary toxicity of a commercially available formulated preparation of Fenvalerate (Fen), a synthetic pyrethroid has been studied in rats following subchronic nose only inhalation exposure route. METHOD: Adult male rats were exposed to Fen for 4 h/day, 5 days a week for 90 days by using Flow Past Dynamic Nose only Inhalation Chamber. RESULTS: Fen exposed rats showed a significant increase in enzymatic activities of lactate dehydrogenase (LDH), acid phosphatase (ACP), alkaline phosphatase (ALP) and gamma-glutamyl transferase (gamma-GT) which are considered as biochemical indicators of pulmonary damage. The concomitant histopathological examination of Fen exposed rats' lung revealed inflammatory changes viz., influx of mononuclear cells admixed with a few giant cells in alveolar lumen, hypetrophied bronchiolar and alveolar epithelial lining cells and presence of edematous fluid in alveolar lumen alongwith congested parenchymatous blood vessels. CONCLUSION: These results for the first time indicate the pulmonary toxic effects of a commonly used formulated Fen preparation by using rat model and nose only inhalation as the route of exposure.

Animals↗
PubMed2001

Solid--cystic papillary tumor of pancreas.

A case of Solid and Cystic Papillary Epithelial Tumor of Pancreas displaying low grade malignancy occurring in a 38 years old female is presented. It is a rare condition and could be diagnosed histopathologically after complete excision.

Adult↗
PubMed2001

Evaluation of influenza virus detection by direct enzyme immunoassay (EIA) and conventional methods in asthmatic patients.

Throat gargle specimens of fifty-seven acute asthmatic patients (age range 18-40 years) were collected for the study. Thirty-four patients were found influenza virus positive in acute asthma cases. Influenza virus was isolated by conventional culture method on MDCK cell-line and by enzyme immunoassay test (EIA). The EIA negative specimens were retested after virus amplification on MDCK cell-line. Virus shedding and virus surface receptors assay was carried out to determine influenza virus titre. Airway functions were measured by spirometry. A good relationship was observed between the degree of airflow limitation and presence of influenza virus infection (p < 0.001; r = 0.85). A comparable difference in % FEV1 was observed in relation to the symptoms. The patients with greater viral antigen load had lower % FEV1. Two specimens, which were EIA negative, turned out to be positive after amplification on MDCK cell-line. The sensitivity was 98% and specificity was 100%. It was concluded that EIA method is a useful diagnostic tool as it detects influenza viral antigen quickly as compared to conventional methods.

Adolescent↗
PubMed2001

Primary multi-drug resistant tuberculous gumma.

A 28-year old lady presented with three discrete gummatous lesions on the anterior abdominal wall, one at the site of a previous laparoscopic scar. Skin biopsy showed epitheloid cell granulomas and a pus culture and sensitivity (for AFB) performed, showed growth of M. tuberculosis. The culture-isolate was resistant to all the essential anti-TB drugs. The patient was put on second line anti-TB chemotherapy and the gummas resolved.

Adult↗