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Biomedical subjects

M Jain

Publications and source records attributed to M Jain.

At least 199 records · Page 11Linked to original sources
PubMed1990

Dietary factors and risk of lung cancer: results from a case-control study, Toronto, 1981-1985.

Associations between dietary factors and risk of lung cancer are reported from a study of 839 cases and 772 population-based controls interviewed in metropolitan Toronto between 1981 and 1985. Increased consumption of vegetables is associated with a decreased relative risk of 0.60 (95% confidence limits = 0.40 to 0.88) for those in the highest compared with the lowest quartile. Cholesterol intake is associated with increased risk, but this is restricted to those in the highest quartile for whom the relative risk is 1.58 (95% confidence limits = 1.05 to 2.38) compared with those in the lowest quartile. The results of this study suggest that dietary factors may affect the risk of lung cancer, but identification of the specific constituents involved will require further research.

Adult↗
PubMed1990

Control of lower esophageal sphincter pressure by two sites in dorsal motor nucleus of the vagus.

Our purpose was to determine the central vagal sites for regulating changes in lower esophageal sphincter (LES) pressure in the cat. Injection of the retrograde tracer, horseradish peroxidase, into the LES resulted in labeling of cells in the dorsal motor nucleus of the vagus (DMV), with the largest number of cells appearing in two areas, one area rostral to obex (1.5-4.0 mm) and one area caudal to obex (-0.5 to -1.5 mm). In alpha-chloralose-anesthetized cats, L-glutamic acid was microinjected into these areas and LES pressure, intragastric pressure, and stomach motility were monitored. Microinjection of L-glutamic acid into the rostral area resulted in significant increases in LES pressure (18.6 +/- 4.9 mmHg; P less than 0.05), pyloric motility (baseline minute motility increased from 5.7 +/- 2.2 to 14.5 +/- 3.9 postinjection; P less than 0.05) and stomach pressure (baseline of 16.9 +/- 2.3 mmHg increased to 23.8 +/- 3.7 mmHg postinjection; P less than 0.05). Microinjection of L-glutamic acid into the caudal area resulted in significant decreases in LES pressure (-14.3 +/- 5.8 mmHg; P less than 0.05) and intragastric pressure (-7.5 +/- 2.2 mmHg; P less than 0.05) with no significant changes in pyloric motility. Ipsilateral vagotomy abolished both sets of responses. These data indicate that excitatory and inhibitory control of LES and intragastric pressure are mediated by vagal efferent neurons located in two distinct sites in the DMV.

Animals↗
PubMed1990

Indian contribution to reproductive physiology: the last 2 decades.

The end of twentieth century is witnessing far-reaching changes in the reproductive behaviour of modern man. Population is doubling now in a record time of 30 years in some parts of the world like India. On the other hand, living-together without marriage and widespread use of contraceptives is making child bearing highly optional in the West. Technological advances in the realm of in-vitro fertilization and genetic manipulation have opened up enormous possibilities, bringing us almost on the verge of Aldous Huxley's Brave New World. It is natural, therefore, that reproduction has become an attractive area of research for physiologists. We review here some of the significant contributions made by Indians to reproduction physiology during the last 20 years (1970-1990). Considerable pruning of available material has been necessary. The emphasis sometimes was on Physiologists although their contribution may not be exactly basic physiology, and sometimes on Physiology although the contributors were not exactly physiologists.

Animals↗
PubMed1990

Experience with internal iliac artery ligation in obstetrics and gynaecological practice.

Internal iliac artery ligation was performed in 6 patients (bilateral in 5), as a prophylactic procedure in 4 and as a life saving measure in 2 patients through transperitoneal approach. No morbidity or mortality resulted from this procedure. All the 6 patients in whom internal iliac artery ligation was done to control an otherwise uncontrollable bleeding from their pelvic tissues had ultimately an uneventful recovery. It is advisable to adopt this procedure as a routine in all difficult pelvic operations particularly radical operations for gynaecological malignancy.

Female↗
PubMed1989

A study of repeatability of dietary data over a seven-year period.

A repeatability study of dietary intake has been carried out using 94 control subjects from a previously reported case-control study of diet and colorectal cancer. Dietary histories readministered on average seven years after an initial interview were used to estimate intake of various macro- and microdietary components. Comparisons of current intake with intake of seven years previously yielded good reliability for macrocomponents among subjects reporting no dietary change during the time period. Reliability was poorer for microcomponents and for subjects reporting a dietary change. Comparisons were also made between diet measured seven years previously with subjects' recall of that diet. It is concluded that current diet is at least as reliable a measure of past diet as that assessed by a questionnaire addressed to the past period.

Aging↗
PubMed1989

Diet history: questionnaire and interview techniques used in some retrospective studies of cancer.

A detailed diet history method that has been used by the Epidemiology Unit of the National Cancer Institute of Canada, Toronto, in retrospective case-control studies is discussed. The questionnaire format and the method of administration by trained interviewers, together with instructions used to train the interviewers, are described. The questionnaire items elicited the usual frequency of foods consumed in the Canadian diet for one or two specified periods of time, including current and/or past diet history. Various probes required to elicit proper information on frequency, serving size, and additions to food are discussed. Portions were quantified by using geometric food models made of papier-mâché, wood, and plastic. The frequency and volumetric measurements obtained from the diet history questionnaire were converted to gram weights using the density of each food consumed; the nutrient intakes were then computed.

Canada↗
PubMed1988

Rupture uterus.

Explore the source record for details and available documents.

Adolescent↗
PubMed1987

Mechanism of sucrose uptake by isolated rat hepatocytes.

The transport of molecules by nonspecific endocytosis has been described in many cell types, but it has not been characterized in hepatocytes. Because of its central role in the clearance of solutes from portal blood, endocytosis might represent a significant mode of cellular transport. We investigated the mechanism of sucrose uptake in an isolated hepatocyte system. Liver cells were isolated by perfusion and collagenization of rat liver, followed by differential centrifugation. Hepatocytes were then incubated with 14C-sucrose and harvested by spinning through oil in microfuge tubes. Radioactivity was standardized against DNA content. We found that sucrose uptake is concentration-dependent from 5 microM to 100 mM and follows first-order kinetics. Washout studies indicate that exocytosis is responsible for the dynamic equilibrium reached. Arrhenius analysis of temperature dependence yields a linear plot (Ea = 14.2 Kcal/mol). In addition, sucrose uptake is independent of cellular ATP levels. We conclude that sucrose is transported by fluid-phase micropinocytosis in isolated hepatocytes and that this transport mechanism may be important in the uptake of diverse molecules into liver cells.

Adenosine Triphosphate↗
PubMed1987

Effect of consumption of iron-fortified salt on iron status in young girls.

The effect of consumption of iron fortified salt for 72 days on levels of haemoglobin and other haematological variables as well as serum levels of protein, iron and total iron binding capacity were investigated in 11 young girls. The consumption of iron-fortified salt increased iron intake, haemoglobin and serum iron and decreased the level of total iron binding capacity.

Adolescent↗
PubMed1987

Consumption of precursors of N-nitroso compounds and human gastric cancer.

It has been hypothesized that dietary nitrate and nitrite are converted in the stomach to nitrous acid, which reacts with secondary amines and amides to form nitrosamines and nitrosamides, compounds frequently demonstrated to be carcinogenic in animals, and that vitamins C and E inhibit N-nitroso product formation by chemically reducing nitrous acid. This hypothesis and others were tested in a case-control study (controls were individually matched by age, sex and area of residence), utilizing a standardized, quantitative, dietary history questionnaire interview. Daily nutrient consumption values were calculated from interview responses, and continuous conditional logistic regression was used for the data analysis. Significant findings are as follows: (1) Average daily consumption of nitrite, chocolate and carbohydrate was associated with increasing trends in risk. (2) While citrus fruit intake appeared to be somewhat protective, any protective effect of vitamin C intake was less apparent, and of vitamin E, not at all apparent. (3) Consumption of dietary fibre was negatively associated with gastric cancer risk. These findings appear to implicate a number of dietary components, including nitrite consumption, in the genesis of gastric cancer in humans.

Adult↗
PubMed1986

Characterization of the forms of beta-endorphin and alpha-MSH in the caudal medulla of the rat and guinea pig.

The post-translational processing of pro-opiomelanocortin (POMC) in brain remains controversial. Classically, there was thought to be a single cell group in the arcuate nucleus with long projections through limbic structures. More recently, a second cell group was discovered in the caudal medulla. This study addresses the question of POMC processing in this region. Steady-state analysis of acid extracts of dorsal caudal medulla from rat and guinea pig CNS by gel filtration chromatography and radioimmunoassay indicated that in both species the major POMC-related end products are alpha-MSH-sized material and beta-endorphin-sized. In this tissue beta-LPH and ACTH represent minor end products. Analysis of the alpha-MSH-sized material from both species by reverse-phase HPLC indicated that in the rat caudal medulla approximately 79% of the alpha-MSH-related material is acetylated, and in the guinea pig caudal medulla approximately 85% of the alpha-MSH-related material is acetylated. Analysis of the forms of beta-endorphin isolated from the rat caudal medulla by cation exchange chromatography revealed that acetylated and non-acetylated forms of beta-endorphin are present in this region of the rat CNS. Approximately 65% of the beta-endorphin in the rat caudal medulla is N-acetylated. Analysis of the forms of beta-endorphin isolated from the guinea pig caudal medulla indicated that approximately 63% of the beta-endorphin is N-acetylated in this region of the guinea pig CNS. These data indicate that the post-translational processing of POMC in the dorsal caudal medulla, the site of the nucleus tractus solitarius POMC cell group, is distinct from the processing patterns that have been reported for POMC systems in the mammalian anterior pituitary, intermediate pituitary and arcuate nucleus.

Acetylation↗
PubMed1986

Possible role of collagen in transverse myelitis and chymopapain-induced paraplegia.

We studied the effect of nucleus pulposus (NP) on platelet aggregation. Our in vitro experiments showed that NP extract produced platelet aggregation and the addition of collagenase to the NP extract abolished this response. It was further shown that chymopapain did not affect the activity of the extract. We assume that collagen is the active platelet aggregant in the NP extract. Intravascular release of collagen may cause platelet aggregation, vascular obstruction, ischemia, and cord necrosis in a patient with acute transverse myelitis. Intradiskal chymopapain is known to cause transverse myelitis and it is possible that collagen released during the action of the enzyme initiates a similar chain of events.

Cartilage↗
PubMed1986

A short diet history for assessing dietary exposure to N-nitrosamines in epidemiologic studies.

A short diet history for use in assessing dietary nitrosamine exposure in epidemiologic studies has been developed by using data from a case-control study of diet and stomach cancer carried out in Ontario, Manitoba, and Newfoundland between 1979 and 1982. The method gives excellent correlations for seven dietary components with estimates based on a full diet history, and also performs well when tested on a different data set from a case-control study of diet and colorectal cancer carried out in Ontario and Alberta between 1976 and 1978.

Alberta↗