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Biomedical subjects

N Bhat

Publications and source records attributed to N Bhat.

33 records · Page 2Linked to original sources
PubMed1997

Country-specific constancy by age in cagA+ proportion of Helicobacter pylori infections.

Helicobacter pylori strains may be either cagA+ or cagA-, and in logitudinal studies, infection with a cagA+ strain has been associated with increased risk for the development of atrophic gastritis and cancer of the distal stomach. We sought to determine the relative proportion of strains producing CagA in different geographic locales, and the extent to which CagA seroprevalence varied in countries with different gastric and esophageal cancer rates. Using an enzyme-linked immunosorbent assay (ELISA) to detect serum IgG to CagA, we examined sera from 468 asymptomatic H. pylori-infected adults from Canada, Peru, China, Thailand, The Netherlands and 3 different ethnic groups in New Zealand. The CagA seroprevalence in Peru and Thailand (82.2% and 78.8%, respectively) were each substantially higher than for the Chinese (37.9%), Canadian (41.9%), Dutch (39.0%) and New Zealand (28.2%) subjects, but within each population, rates were relatively constant across gender and age groups. Reported gastric but not esophageal cancer rates for the 8 studied populations were significantly associated with H. pylori seroprevalence. Variation in CagA positivity rates was not significantly associated with variation in either gastric or esophageal cancer rates. Our data suggest that CagA seroprevalence is not the major factor influencing gastric cancer rates.

Adult↗
PubMed1993

Detergent permeabilized yeast cells as the source of intracellular enzymes for estimation of biomolecules.

The feasibility of using permeabilized whole cells as a source of intracellular enzymes instead of isolated expensive enzymes for the estimation of biomolecules has been studied. Alcohol dehydrogenase (ADH), glucose-6-phosphate dehydrogenase (G6PDH), hexokinase (HK), and beta-galactosidase (beta-GAL) activities of cetyltrimethylammonium bromide (CTAB)-permeabilized whole yeast cells were employed to estimate ethyl alcohol, glucose, and lactose. The method using permeabilized cells was comparable to that of isolated enzymes and was applicable for the estimation of these analytes in complex samples such as blood, milk, and fermented samples. The usefulness of permeabilized cells as a single source of more than one enzyme required for coupled enzyme assays was demonstrated.

Alcohol Dehydrogenase↗
PubMed1993

Broken tracheostomy introducer--an unusual tracheobronchial foreign body.

We present a rare case where the introducer of a metal tracheostomy tube became lodged in the tracheobronchial tree. This may be the only reported case. The literature is reviewed to study the possible cause of tracheostomy tube component fracture and to suggest methods for preventing this complication.

Bronchography↗
PubMed1992

Ontogeny of human natural killer (NK) cells: fetal NK cells mediate cytolytic function and express cytoplasmic CD3 epsilon,delta proteins.

Natural killer (NK) cells have been defined as CD3 epsilon-, CD16+ and/or CD56+ lymphocytes that mediate major histocompatibility complex (MHC)-unrestricted cytotoxicity against certain tumors and virus-infected cells. Unlike T lymphocytes, NK cells do not rearrange or productively express T cell antigen receptor genes. Moreover, NK cells from adults have been reported to not express CD3 gamma, delta, or epsilon proteins on the cell surface or in the cytoplasm. Nonetheless, NK cells have been shown to share a number of antigenic and functional similarities to T cells that suggest the possibility of common origins. In this report, we demonstrate that functional NK cells exist in liver at early stages of human embryonic development. Freshly isolated fetal NK cells mediated MHC-unrestricted cytotoxicity against NK-sensitive targets and acquired the ability to lyse NK-resistant tumors after overnight culture in interleukin 2. Unlike adult NK cells, freshly isolated fetal liver NK cells and clones derived from these cells, as well as a subset of cord blood NK cells, express substantial levels of CD3 delta and CD3 epsilon proteins in the cytoplasm. Expression of CD3 epsilon and CD3 delta transcripts and cytoplasmic proteins in fetal NK clones was confirmed by polymerase chain reaction and Western blot analysis. These findings support the concept that NK and T cells may arise from a common progenitor that expresses components of the CD3 complex. Alternatively, it is possible that the cytoplasmic CD3 delta, epsilon+ fetal NK cells represent a distinct subpopulation of NK cells that is predominant in the fetus, but replaced by the cytoplasmic CD3 delta,epsilon- adult NK cell population after embryogenesis.

Antigens, CD↗
PubMed1991

Pregnancy interceptive efficacy and biological profile of 3-amino-6,7-dimethoxy-1H-pyrazolo [3,4-b] quinoline (compound 85/83) in rodents.

Administration of compound 85/83 during the peri- and post-implantation period intercepted pregnancy in hamster and guinea pig by parenteral route and in hamster by oral route also. The m.e.d. for hamster and guinea pig was 10 and 20 mg/kg, respectively; lower doses were less effective. Restricting the administration to early post-implantation schedule interrupted pregnancy partially in both species. The compound was, however, ineffective in rat and in the pre-implantation schedule (days 1-4 post-coitum) in hamster. When tested in vitro on growing trophoblasts at 13.8 x 10(-5) M concentration, it prevented growth and caused degeneration of the cells within 24 h; lower concentration (9.2 x 10(-5) M) was less effective. The compound was found to be devoid of estrogenic, antiestrogenic, progestational and antiprogestational properties in conventional bioassays. In hormone competition assays, its relative binding affinity (RBA) to estrogen receptor was negligible (0.002% of estradiol-17 beta), while for uterine cytosol progesterone receptors in rabbit and hamster was 0.06 and 0.08% of progesterone, respectively. The compound 85/83 appears to intercept pregnancy by interfering with development of trophoblast cells.

Administration, Oral↗
PubMed1990

Transbronchial needle aspiration biopsy in the diagnosis of pulmonary neoplasms.

To evaluate the usefulness of transbronchial needle aspiration biopsy (TBNAB) in the primary diagnosis of lung cancer, we undertook a prospective study of this technique, assessing specimens from 124 patients over a 3-yr period. Cytologic and/or histologic material obtained by an alternate technique was available for 105 (84.7%) of the patients. The diagnostic sensitivity of TBNAB was comparable with that of other bronchoscopic techniques; with the addition of TBNAB, the overall sensitivity of bronchoscopy was increased from 54% to 72% (P less than 0.001). Because of its usefulness for diagnosis of submucosal tumors and its safety, we conclude that TBNAB is a useful addition to current methods for the diagnosis of suspicious pulmonary lesions.

Biopsy, Needle↗
PubMed1985

Paradoxical response to intravenous terbutaline.

Marked uterine hypertonus was observed in our patient subsequent to the intravenous administration of terbutaline prior to an attempt at external cephalic version. The proximity of hypertonus to terbutaline infusion and the absence of other stimuli suggests that this was a paradoxical response to terbutaline.

Adult↗
PubMed1984

Cytoskeletal structures and oligodendroglial differentiation in C-6 glial cells.

The relationship of the cytoskeleton to a biochemical expression of oligodendroglial differentiation was studied in cultured C-6 glial cells. Specifically, we investigated the effect of the cytoskeletal perturbants, colchicine and cytochalasin D, on the induction of the oligodendroglial marker enzyme, 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP), caused by removal of serum from the culture medium. Each drug inhibited CNP induction in a concentration-dependent manner, and essentially complete inhibition of induction was observed with 0.25 microM colchicine or 2.0 microM cytochalasin D. Detailed study of the effect of colchicine was carried out. This antimicrotubular agent not only totally prevented induction if added at the onset of serum removal, but also prevented further induction when added at various times after serum removal. That the effect of colchicine related to the drug's effect on microtubules was supported by the demonstration that lumicolchicine, a colchicine isomer which has no effect on microtubules, had no effect on the CNP induction. Moreover, colchicine, but not lumicolchicine, prevented the morphological signs of differentiation provoked by serum removal. The effect of colchicine was reversible and relatively specific. Thus, no concomitant effect of colchicine on the activity of another plasma membrane enzyme of C-6 cells, i.e., (Na+ + K+)-activated ATPase, or on the rate of incorporation of [3H]leucine into total protein of intact cells could be discerned. The possibility that the site of the effect of colchicine is on intracellular events was suggested by the observation that the drug inhibited the induction of CNP by dibutyryl cyclic AMP. The data suggest that the cytoskeleton is involved in oligodendroglial differentiation.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗
PubMed1983

Evaluation of the teratogenic potential in Ciba-Geigy Go 10213, a new nitroimidazole derivative: 1-methane-sulphonyl-3-(1-methyl-5-nitro-1H-imidazole-2-yl)-2- imidazolidinone, an amoebicide, trichomonicide and giardicide, in giardicide, in rats.

With a view to evaluate the possible teratogenic potential of 1-methane-sulphonyl-3-(1-methyl-5-nitro-1H-imidazole-2-yl)-2-imidazolidi none (Go 10213), groups of pregnant rats were medicated orally with: 0, 100, 300 and 600 mg/kg of the compound daily from day 6 to day 15 of gestation. Foetuses were removed on day 20 of gestation, and were examined for their mortality, size, weight and any gross malformation. One third of the foetuses were fixed in Bouin's Fluid and sectioned by Wilson's technique for histological evaluation. The remaining pups were examined for the skeletal anomalies. CIBA-GEIGY Go 10213 appears to be neither embryotoxic nor teratogenic to the rat-foetuses, when the mothers were medicated at the aforesaid doses, during their critical phase of the pregnancy.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

Residual trophoblastic tissue as a source of highly atypical cells in the postpartum cervicovaginal smear.

A cervicovaginal smear containing atypical cells, which were interpreted as dysplastic cells, was obtained from a women one-year postpartum. These cells were seen singly, in small groups and in clusters embedded in an amorphous pink matrix. They had amphophilic cytoplasm and increased nuclear/cytoplasmic ratios, as well as hyperchromatic nuclei with variably prominent nucleoli, features that are characteristic of trophoblastic cells. No evidence of dysplasia was seen on subsequent colposcopic examination or cervical biopsy. Endocervical curettage yielded fragments of exfoliated endometrium and residual trophoblastic tissue associated with a placental implantation site. Although involution of the placental site is generally complete by six to seven weeks postpartum, maternal-fetal tissue may in fact continue to be exfoliated for several months or longer after delivery. If seen on a cervicovaginal smear, these cells can be highly atypical and may be mistaken as dysplastic or malignant. The cytologic features that characterize trophoblasts and their persistence in postpartum cervicovaginal smears are discussed.

Adult↗
PubMedDate not supplied

Gynecomastia in a mortician. A case report.

The fine needle aspiration (FNA) observations in a case of gynecomastia occurring in a mortician are described. The FNA smear showed cytomorphologic features typical of a gynecomastia. Morticians use an embalming cream that contains estrogens or estrogenlike compounds; these substances may be absorbed percutaneously and cause the development of gynecomastia. The mortician should be made aware of the potential risk of such an occupational exposure and development of the "embalmer's curse. "Recognition by the clinicians and cytopathologists of such an occurrence and its implications can help with the proper management.

Adult↗