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Biomedical subjects

S Mathur

Publications and source records attributed to S Mathur.

At least 19 recordsLinked to original sources
PubMed1992

Immunohistochemical studies on the innervation of human transplanted liver.

The changing pattern of innervation in the human transplanted liver was studied from the day of transplantation to 5 years later. Seven liver biopsies from non-transplant controls, 37 liver biopsies from 22 transplant patients, and one of these biopsied livers removed at retransplantation, were available for the study. Sections were immunostained for protein gene product 9.5 (PGP 9.5), neurone-specific enolase (NSE), S-100 protein, and vasoactive intestinal polypeptide. NSE and PGP 9.5 demonstrated nerves most successfully in our tissues. Staining for most small nerves was reduced by day 5 post-transplantation. Scanty fine nerves could be detected from day 13 to day 241 in occasional biopsies. Consistently identifiable immunostaining of PGP 9.5 and NSE nerve fibres was again apparent in portal areas after this time in all but one case. The findings indicate that in transplanted liver limited reinnervation can eventually take place. This could be due to either proliferation of intrinsic nerves, or regrowth of extrinsic nerves, or both.

Humans↗
PubMed1992

Reset of the osmotic threshold for vasopressin in rats fed a low NaCl, K-free diet.

Activation of the renin-angiotensin system induced by feeding a low NaCl, K-free (LS) diet is associated with polydipsia and a chronic reduction in effective plasma osmolality (efPosm). We have recently shown that converting enzyme inhibition with enalapril (EP) abolishes polydipsia. The present study was designed to test the hypothesis that the osmotic threshold for vasopressin is reset in rats fed the LS diet and to examine the effect of EP on ambient and osmotically stimulated plasma vasopressin levels (PAVP). Animals were fed the LS diet or a control salt diet and treated with vehicle or the lowest dose of EP sufficient to prevent polydipsia (7.5 mg.kg-1.day-1) in rats fed the LS diet. PAVP and efPosm were measured under ambient conditions and after osmotic loading. Urine osmolality (Uosm) was measured under ambient conditions and after water loading. The chronic reduction in efPosm in LS rats was associated with the excretion of a Uosm 1-2 times greater than the corresponding Posm, PAVP similar to controls (LS, 2.27 +/- 1.08 vs. control, 1.19 +/- 0.22 pg/mL) and the ability to excrete a water load. Following osmotic loading, efPosm and PAVP increased significantly and similarly in both LS and control rats. EP administration had no effect on water intake, ambient efPosm and PAVP, and the AVP response to osmotic loading in rats fed the control diet. EP prevented polydipsia in LS rats, however it had no significant effect on ambient or osmotically stimulated PAVP or efPosm.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Lactation failure.

Seventy five mothers with lactation failure were studied, whose less than 4-month-old babies were admitted to the hospital. Partial lactational failure (94.7%) was noted more often than complete lactational failure (5.3%). Initiation of breastfeeding was delayed for 2 to 5 days usually for traditional reasons (77.3%) and because the mothers felt that the milk output was inadequate (92%). The various causes of lactation failure were determined and the relationship to various factors was analyzed. The commonest cause of lactation failure was insufficient milk or no milk (80%). The age, parity, education, socio-economic status, religion, family structure and urban vs rural status of mother--all had a bearing on the occurrence of lactation failure. An attempt was made to relactate all these mothers. The outcome was successful in 69.3 cases and failed in only 4% cases. In 26.7% cases, we cannot predict the outcome as the mothers hospital stay was very brief with no follow up.

Adolescent↗
PubMed1992

Bleeding from a Meckel's diverticulum after the use of ibuprofen.

A Meckel's diverticulum is an unusual site of gastrointestinal bleeding in adults. Bleeding often results from ulceration of ileal mucosa that lies adjacent to ectopic gastric mucosa. We report on a 27-yr-old man who bled from a Meckel's diverticulum after receiving oral ibuprofen, a nonsteroidal antiinflammatory drug. Examination of the resected diverticulum revealed fundal-type gastric mucosa with inflammation, submucosal hemorrhages, erosions and ulceration in the absence of Helicobacter pylori. The ileal mucosa was spared in this patient. These features suggest that oral ibuprofen caused damage to the ectopic gastric mucosa, precipitating significant hemorrhage. This is the first report in the English literature of such an occurrence.

Adult↗
PubMed1991

Epstein Barr virus/complement C3d receptor is an interferon alpha receptor.

Interferon alpha contains a sequence motif similar to the complement receptor type two (CR2/CD21) binding site on complement fragment C3d. Antibodies against a peptide with the CR2 binding sequence on C3d react with a peptide carrying the IFN alpha CR2 binding motif (residues 92-99) and with recombinant IFN alpha. The IFN alpha-derived peptide, as well as recombinant IFN alpha, inhibits C3bi/C3d interaction with CR2 on the Burkitt lymphoma Raji. The direct interaction of IFN alpha and CR2 is inhibited by polyclonal anti-IFN alpha, anti-CR2 and anti-C3d peptide antibodies as well as by C3bi/C3d, EBV coat protein gp350/220 and IFN but not by IFN gamma. [125I]IFN alpha binding to Raji cells is inhibited by polyclonal anti-IFN alpha and anti-CR2 antibodies, by peptides with the CR2 binding motif and partially by C3bi/C3d. Monoclonal anti-CR2 antibody HB5, but not OKB-7, blocks IFN alpha binding to Raji cells. CR2 or CR2-like molecules may therefore be the major IFN alpha receptors on B lymphocytes.

Amino Acid Sequence↗
PubMed1991

Inhibition of acylcoenzyme A: cholesterol acyltransferase activity by PD128O42: effect on cholesterol metabolism and secretion in CaCo-2 cells.

The regulation of cholesterol uptake and secretion by acylcoenzyme A:cholesterol acyltransferase (ACAT) was investigated in the human intestinal cell line, CaCo-2. A new ACAT inhibitor, PD128042 (CI-976), was first characterized. The addition of the fatty acid anilide to membranes prepared from CaCo-2 cells inhibited ACAT activity without altering the activities of HMG-CoA reductase, fatty acid Co-A hydrolase, or triglyceride synthetase. PD128042 was a competitive inhibitor of ACAT with 50% inhibition occurring at a concentration of 0.2 micrograms/mL. When added to the medium of CaCo-2 cells at a concentration of 5 micrograms/mL, PD128042 inhibited oleate incorporation into cholesteryl oleate by 92% and increased oleate incorporation into triglycerides and phospholipids by 51% and 38%, respectively. After incubating CaCo-2 cells with the ACAT inhibitor, the rate of newly synthesized cholesterol decreased by 75% and membranes prepared from these cells contained significantly less HMG-CoA reductase activity. PD128042 significantly decreased the basolateral secretion of newly synthesized cholesteryl esters without affecting the secretion of newly synthesized triglycerides or phospholipids. The inhibitor decreased the esterification of labeled exogenous cholesterol which was taken up by the cell from bile salt micelles. Moreover, after 16 hr of ACAT inhibition, less labeled unesterified micellar cholesterol was associated with the cell. The esterification of cholesterol in CaCo-2 cells plays an integral role in the uptake of cholesterol through the apical membrane and its eventual secretion at the basolateral membrane.

Acyl Coenzyme A↗
PubMed1991

Radioprotection by MPG of mice ovaries exposed to sublethal gamma radiation doses at different postnatal ages.

Female Swiss albino mice were exposed at 1, 3 or 6 weeks of age respectively to sublethal doses (0.6, 1.2 and 2.4 Gy) of gamma radiation in the presence or absence of 2-mercaptopropionylglycine (MPG). Ovaries were histologically examined at different intervals after irradiation and the follicles were counted. Most follicular depletion had occurred already at postirradiation day 1 and the depletion then gradually continued. At day 35 after irradiation a few follicles could still be found in mice exposed at 1 week of age while all follicles were eliminated in mice exposed at 3 and 6 weeks of age. In MPG-treated animals the depletion of follicles was significantly less pronounced and obviously MPG to some degree protected the ovaries from radiation damage.

Age Factors↗
PubMed1991

Poliomyelitis with special reference to immunization status.

One hundred ninety one children below 5 years of age suffering from poliomyelitis were analyzed to find out the immunization status and its correlation with the incidence of poliomyelitis. Effects of age, sex, immunization status and seasonal variation on the morbidity and mortality status were studied. The maximum number of cases were admitted during the months of July (23.6%) and August (23.1%). Of 191 cases, 143 (74.9%) had no immunization and 48 (25.1%) were partially immunized. A total of 155 (81.2%) cases had spinal polio, 23 (12.01%) bulbo-spinal polio, and 13 had (6.8%) bulbar polio. Serious illness (bulbospinal and bulbar type) was more in partially immunized children (25%) as compared to unimmunized children (16.8%). The mortality rate was more than two times higher in the partially immunized (29.6%) as compared to unimmunized children (11.2%). The possible explanation for high mortality in partially immunized children could be due to the adverse effect of OPV which has not been studied so far.

Age Factors↗
PubMed1991

Hepatitis B virus infection and its transmission in preschool children.

In the present study, 2.5% of 367 preschool children has HBsAg positivity. Of 11 mothers who were HBsAg positive during the third trimester of pregnancy, 4 had babies (36.4%) who developed HBsAg positivity by 2.5-3 months of age (vertical transmission). Two babies born of HBsAg negative mothers, with history of jaundice during first trimester, were HBsAg negative. All the relatives of HBsAg positive cases screened were negative for HBsAg.

Child, Preschool↗