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Biomedical subjects

M Singh

Publications and source records attributed to M Singh.

At least 955 records · Page 53Linked to original sources

Pancreatic acinar cell function and morphology in rats fed zinc-deficient and marginal zinc-deficient diets.

The prevalence of marginal zinc nutriture in several populations of people in this country and the lack of reports on the effect of marginal zinc nutriture in experimental animals prompted us to look at pancreatic acinar cell function and morphology in rats fed a zinc-deficient diet ad libitum: 4 and 50 ppm zinc-supplemented diets in amounts isocaloric to a zinc-deficient diet and Rodent-Blox fed ad libitum for a period of 49 +/- 1 (SEM) days. Because of a diminished rate of energy expenditure in zinc-deficient rats, animals receiving 50 ppm zinc-supplemented diets were offered less food, resulting in decreased body weight and pancreas weight, DNA, RNA, total protein, lipase, amylase, and secretion of protein. Specific changes due to zinc deficiency included (a) further decrease in body weight and (b) increase in content, specific activity, and secretion of lipase. Both the size and volume fraction of zymogen granules were reduced in zinc deficiency. The lumina of acinar and small ducts were collapsed with paucity of secretion products. Zinc deficiency may therefore lead to a defect in discharge mechanism. A further reduction in volume fraction of zymogen granules in the 4 ppm zinc-supplemented group was associated with increased secretion of serine proteases (trypsinogen and chymotrypsinogen), which constitute approximately 46% of total secretory protein in the pancreas under normal dietary conditions. This indicated an accelerated discharge due to an unknown mechanism. Changes in the secretion of digestive enzymes in the present study simulated ethanol-induced secretory alterations that were previously observed. Because abnormal zinc nutriture and chronic alcoholism are commonly associated, it is speculated that zinc deficiency may play a role in the ethanol-induced secretory alterations.

Amylases↗

Blunt renal injury--an experience of 30 cases.

Thirty cases of blunt renal injury are reviewed. The need for rapid and accurate diagnosis of these cases with excretory urography, supplemented in certain patients with renal angiography, is discussed. High-dose excretory urography allows the cases to be categorized into minor or major injuries. All minor injuries can be managed without operation. For major injuries, a conservative approach, if necessary followed by surgical exploration, avoids loss of organ in most of the cases.

Adolescent↗

Use of polyglycolic acid mesh to confine particulate hydroxylapatite for augmentation of bone in the rat.

A preliminary report of the use of polyglycolic acid (PGA) mesh to contain particulate nonresorbable hydroxylapatite (HA) used for augmentation of bone in rats is presented. PGA mesh tubes, approximately 2 mm in diameter and 5 mm in length, were fabricated, filled with HA, and placed in surgically created subperiosteal pockets against the medial cortex of the tibia in rats. Specimens were obtained at two, six, 12, and 18 weeks. The results showed that when the HA was contained within the PGA mesh, severe displacement of particles was prevented and greater HA augmentation was possible. Absorption of the mesh took place between six and 12 weeks, after which the histologic features were the same as those seen when HA was implanted alone. Grossly, the implants appeared to hold firmly to bone even two weeks after implantation. A new, more efficacious delivery system is proposed for the augmentation of atrophic alveolar ridges using HA contained within PGA mesh tubes.

Alveolar Ridge Augmentation↗

An investigation of the H1-receptor antagonist triprolidine: pharmacokinetics and antihistaminic effects.

A single oral dose of triprolidine hydrochloride, 0.04 mg/kg (mean dose 2.7 +/- SD 0.4 mg) was administered to seven healthy, fasting adult volunteers who had never been treated previously with H1-receptor antagonists. Blood sampling and intradermal tests with 0.01 ml of histamine phosphate (0.1 mg/ml) were performed at -0.25, 1, 2, 3, 4, 5, 6, 7, 8, and 12 hours after the dose. Wheal-and-flare circumferences were traced, and the areas were measured by planimetry. Pruritus was quantitated by use of a clinical score. Urine was collected in 6-hour pooled aliquots for a total of 24 hours. Serum and urine triprolidine concentrations were measured by high-performance liquid chromatography. Wheal-and-flare areas and pruritus decreased after the triprolidine dose. Suppression of mean flare size was statistically significant at 2, 3, 6 and 8 hours. Suppression of mean wheal size was not statistically significant at any time compared to predose values. The mean triprolidine serum half-life was 2.1 +/- 0.8 hours. The mean peak serum triprolidine concentration of 15.4 +/- 8.3 ng/ml occurred 2 hours after ingestion. No triprolidine was detected in the serum after 12 hours. The mean urinary excretion of unchanged triprolidine during 24 hours was 1.3 +/- 1.0% of the dose administered.

Adult↗

Effect of niacin and niacin-tryptophan deficiency on pancreatic acinar cell function in rats in vitro.

To determine the effect of niacin deficiency on pancreas, rats were fed a standard rat chow ad libitum or an equal amount of a niacin-deficient or niacin-sufficient diet in the first experiment, or of a niacin-tryptophan-deficient or niacin-tryptophan-sufficient diet in the second experiment. Niacin deficiency decreased tissue chymotrypsinogen and trypsinogen content; amylase, chymotrypsinogen, and trypsinogen concentration; and basal secretion of total protein. Niacin-tryptophan deficiency decreased body weight, pancrease weight, and content of DNA, protein, amylase, lipase, chymotrypsinogen, and trypsinogen. Secretion of amylase and trypsinogen was increased. These studies indicate that niacin and niacin-tryptophan deficiency alter digestive-enzyme content and secretion, probably due to metabolic aberrations that result in an altered redox state of the acinar cell.

Amylases↗

Pulmonary and extrapulmonary lymphangioleiomyomatosis. Report of a case with bilateral renal angiomyolipomas, multifocal lymphangioleiomyomatosis, and a glial polyp of the endocervix.

The authors report an extraordinary case of a 33-year-old female who had pulmonary and extrapulmonary lymphangioleiomyomatosis, bilateral renal angiomyolipomas, multifocal lymphangioleiomyomatosis involving the uterus, ovaries, periadrenal vessels, and liver. The patient also had a glial polyp of the endocervix which represented retained fetal parts from an abortion 15 years earlier. Both ovaries showed multiple follicle cysts which may have been a source of endogenous estrogen. The classical stigmata of the tuberous sclerosis complex were absent. The multifocal lymphangioleiomyomatosis of the various organs described presents an extremely rare manifestation of this disorder.

Adult↗

Hydropneumothorax following peritoneoscopy.

Peritoneoscopy is recognized as a safe and effective procedure, even though numerous complications have been reported. We have seen a patient in whom left hydropneumothorax developed after laparoscopy, a complication not previously reported.

Adult↗

Modification by sex of diet and ethanol effect on rat pancreatic acinar cell metabolism.

The present study was done to determine the role of sex of the animal on the effect of diet and ethanol on pancreatic acinar cell function. Weight-matched groups of Sprague-Dawley rats of either sex were divided into groups of three each and fed Wayne Lab-Blox ad libitum, Lieber-DeCarli diet with 36% of carbohydrate calories replaced with ethanol ad libitum, and Lieber-DeCarli diet in an amount isocaloric to ethanol-fed animals for a period of 3 months. Despite similar amounts of protein, fat, and carbohydrates fed to male and female rats, the female rats had lower amylase content in the tissue when fed Lieber-DeCarli diet and a higher specific activity of trypsinogen in the tissue of animals fed Lab-Blox. Specific activity of chymotrypsinogen increased in males fed Lieber-DeCarli diet and decreased in females fed the same diet when compared with animals of the same sex fed Lab-Blox. Secretion of various digestive enzymes was also different in male and female rats, whereas trypsin inhibitor secretion was similar. These data indicate different adaptive responses in male and female rats to diets with similar proportions of nutrients. When ethanol-fed male rats were compared with ethanol-fed female rats, there was a significant increase in secretion of trypsinogen and amylase (and a proportional but statistically nonsignificant increase in lipase) in female rats. These data indicate that chronic feeding of ethanol results in a nonparallel secretion of digestive enzymes in both sexes with a greater discordance between the trypsinogen secretion and trypsin inhibitor in female rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Amylases↗

Interaction between marginal zinc deficiency and chronic alcoholism: pancreatic structure and function in rats in vitro.

The present study was done to determine interaction of ethanol and marginal zinc nutriture on morphology and function of rat pancreas. Sprague-Dawley rats were maintained on Wayne Rodent-Blox ad libitum; marginal zinc-deficient diet plus ethanol ad libitum and pair fed with animals fed marginal zinc-deficient liquid diet and zinc-supplemented liquid diet with ethanol for 33 (+/- 1 SEM) days. Body, pancreas, liver, heart, and kidney weights were determined, and studies of pancreatic DNA, RNA, total proteins and newly labeled proteins, amylase, lipase, trypsinogen, and chymotrypsinogen were done on pancreatic lobules in vitro. Ethanol feeding independent of the zinc content of the diet caused a decrease in zinc content of the liver, body weight, liver and pancreas weight, pancreatic DNA, total protein, and amylase concentration and an increase in lipase and trypsinogen concentrations and in secretion of amylase and lipase. Interaction of the marginal zinc diet and ethanol feeding resulted in a decreased synthesis of RNA and secretion of newly synthesized protein and an increase in secretion of serine proteases. Morphological studies revealed a reduction in the number of zymogen granules in animals fed low levels of zinc, also with an accumulation of lipid droplets when the diet contained ethanol. These studies confirmed our previous observations of specific injury to the pancreas due to marginal zinc nutriture or to ethanol, independent of each other. Marginal zinc nutriture in concert with ethanol resulted in impaired RNA synthesis and secretion of nascent proteins and increased secretion of serine proteases. These data indicate that altered zinc metabolism induced by ethanol per se may contribute to ethanol-induced disturbance of pancreatic function.

Alcoholism↗

Study of tear film flow and break up time (BUT) in trachoma.

Tear film flow and stability studies were carried out in patients suffering from cicatrizing trachoma by Schirmer test I and tear film break-up-time (BUT) measurements, respectively. Both Schirmer test I and BUT values were decreased significantly (t-test, P less than 0.001) depicting aqueous as well as mucin deficiency and hence, an unstable tear film in this condition.

Adult↗

Tear film flow and stability in herpes simplex keratitis and chronic blepharitis.

Tear film flow and stability studies were carried out in patients suffering from herpes simplex keratitis and chronic blepharitis by performing Schirmer test I and tear film break-up-time (BUT) measurements. In herpes simplex keratitis the values of BUT were within normal limits. Values of Schirmer test I were significantly higher (t-test, P less than 0.001) in these patients and are considered to be due to reflex hypersecretion of tears. Schirmer test I was found to be unaffected, whereas the values of BUT seen were significantly lower (t-test, P less than 0.001) in patients suffering from chronic blepharitis. These lower values of BUT can perhaps be attributed to the altered resurfacing of precorneal tear film as a result of changes in the lid margins.

Blepharitis↗

Postural behaviour of intraocular pressure in diabetics.

The response to posture of intraocular pressure (IOP) was studied in 58 normal and 60 diabetic eyes. A significant postural rise of IOP was found in the diabetic patients. The clinical relevance of the abnormality in pressure regulation in diabetics is discussed. Its implications for other closely associated disorders are emphasized.

Adult↗