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Biomedical subjects

J Tiwari

Publications and source records attributed to J Tiwari.

12 recordsLinked to original sources
PubMed2001

Chemosensitivity of serotonergic neurons in the rostral ventral medulla.

The medullary raphé contains two subtypes of chemosensitive neuron: one that is stimulated by acidosis and another that is inhibited. Both types of neuron are putative chemoreceptors, proposed to act in opposite ways to modulate respiratory output and other pH sensitive brain functions. In this review, we will discuss the cellular properties of these chemosensitive raphé neurons when studied in vitro using brain slices and primary dissociated cell culture. Quantification of chemosensitivity of raphé neurons indicates that they are highly sensitive to small changes in extracellular pH (pH(o)) between 7.2 and 7.6. Stimulation by acidosis occurs only in the specific phenotypic subset of neurons within the raphé that are serotonergic. These serotonergic neurons also have other properties consistent with a specialized role in chemoreception. Homologous serotonergic neurons are present within the ventrolateral medulla (VLM), and may have contributed to localization of respiratory chemoreception to that region. Chemosensitivity of raphé neurons increases in the postnatal period in rats, in parallel with development of respiratory chemoreception in vivo. An abnormality of serotonergic neurons of the ventral medulla has been identified in victims of sudden infant death syndrome (SIDS). The cellular properties of serotonergic raphé neurons suggest that they play a role in the CNS response to hypercapnia, and that they may contribute to interactions between the sleep/wake cycle and respiratory control.

Animals↗
PubMed2000

Study of lymphatic metastatic patterns in gastric carcinoma according to tumor location.

A total of 226 cases of advanced gastric cancer which occupied only one third of the stomach were analyzed in order to clarify whether and how lymphatic spread differed according to the tumor location and gross type of tumor. Out of the 226 patients, 45 cases had tumor in the upper third, 74 cases had it in the middle third, and 107 cases had it in the lower third of the stomach. The incidence of lymph node metastasis was found to be much higher for the tumors located in the lesser curvature (51.6%), greater curvature and posterior wall (54.4%), as compared to the tumors located in the anterior wall (28.0%). The tumors located in the upper third of the stomach did not show any metastasis in the N3 node, while the tumors located in the lower third of the stomach did not show any metastasis in the left cardial nodes, short gastric nodes, and the nodes along the left gastroepiploic vessels. Similarly, the tumors from the middle third of the stomach did not invade the left cardial nodes.

Adult↗
PubMed1994

Relation between maternal age and serum concentration of IgG antibody to type III group B streptococci.

Coded serum samples collected from healthy obstetric patients at delivery were examined by ELISA for IgG antibody to the purified type III polysaccharide of group B streptococci. When 217 patients were divided into 4 groups according to age (group I =16-20 years, n = 56; group II = 21-25, n = 53; group III = 26-30, n = 54; group IV = 31-35, n = 54), antibody concentrations were significantly lower in group I than in older patients. Fewer subjects in group I had measurable antibody levels (> or = 0.05 microgram/mL) than in groups II-IV (41% vs. 76%, P < .001). The geometric mean in group I (0.09 microgram/mL) was significantly lower (P < .001) than in the older groups (0.23, 0.19, and 0.20 microgram/mL, respectively) with little or no overlap of the 95% confidence limits (1.96 SE) about the means. These findings may be relevant to the observation of a significantly greater risk of both early- and late-onset group B streptococcal disease in infants of teenage mothers.

Adolescent↗
PubMed1990

Complications following surgery for cancer of the larynx and pyriform fossa.

The hospital records of patients undergoing major surgery for cancer of the larynx and hypopharynx at the Tata Memorial Hospital, Bombay, from 1981 to 1985 were reviewed. Different variables were correlated with the incidence of major complications and were analysed to find out significant factors contributing to increased complication rates. Complications included wound infection, pharyngocutaneous fistulae, flap necrosis, carotid blowout, and neo-esophageal stenosis. Postoperative deaths and delayed fatalities were also recorded. The overall fistulae rate was 34.7%, and wound infection occurred in 28% of patients. Prior radiotherapy and the need for pharyngeal reconstruction were found to be significant in determining postsurgical complications. Age, sex, site, stage, cartilage and soft tissue infiltration, preoperative tracheostomy, involvement of resection margins by tumor, and the dose of radiotherapy were not found to influence the complication rates.

Adult↗
PubMed1989

Observations on Indian node-negative breast cancer patients: a multivariate analysis.

The modern treatment of breast cancer has evolved over the past 100 years based on clinical observations. Therapeutic principles, from the choice of surgical procedure to the management of disseminated disease, have also changed. The axillary tumour burden, that is, the number of histologically positive nodes (N+) plays an important role as a prognostic factor. However, in histologically Negative nodes (N-), it is necessary to discriminate individuals at high risk despite negative nodes. This presentation analyses retrospectively the prognostic factors for long-term failures in N- patients. These prognostic factors need to be studied in detail, and controlled clinical trials should be carried out to detect high risk N- patients and consider them for adjuvant chemotherapy.

Antineoplastic Agents↗
PubMed1988

HLA and schizophrenia in Israel.

Thirty-two Israeli Jewish schizophrenic patients were typed for Class I (HLA-A, B, C) and Class II (HLA-DR) antigens. A significant increase of HLA-A2 (P = 0.01) and A23 (P = 0.02) was found. None of the 10 HLA-DR antigens tested was associated with the disease. Study of eight families indicated that close linkage of the gene responsible for this disorder to the HLA system is unlikely.

Adult↗
PubMed1983

Family studies of the HLA system in acute post-streptococcal glomerulonephritis.

Eighteen families (67 siblings) of index cases with acute post-streptococcal glomerulonephritis (APSGN) were typed for HLA-A,B,C,DR antigens. Twenty cases of clinical nephritis and 10 cases of asymptomatic disease with detected among the sibships. In eight families with more than one affected individual comprising 18 sib pairs random segregation of paternal and maternal HLA haplotypes was found (0.5 less than p less than 0.06), but some antigens (CW1, DR3) showed deviation from the expected 1:1 ratio in affected and nonaffected siblings in backcross families. We had previously noticed the existence of Mendelian recessive ratios in APSGN but in the absence of clear evidence for a dominant or recessive mode of inheritance for a putative APSGN susceptibility gene(s), pedigree data were analyzed twice for linkage with HLA using the two genetic models. The data obtained, although not sufficient to reject the hypothesis of linkage, provide no support for it. Comparison of the frequency of 61 HLA antigens among 42 unrelated APSGN patients and 109 controls, showed that HLA-DRW4 is more frequent among the former (pc = 0.0500).

Acute Disease↗