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Biomedical subjects

A Singh

Publications and source records attributed to A Singh.

At least 613 records · Page 34Linked to original sources
PubMed1989

Magnesium, zinc, and copper status of US Navy SEAL trainees.

Magnesium, zinc, and copper status of 270 US Navy Sea, Air, and Land (SEAL) trainees was determined from dietary intakes and biochemical profiles. Although mean intakes exceeded the Recommended Dietary Allowances or the Estimated Safe and Adequate Intake range, intakes of 34%, 44%, and 37% of the trainees were below the recommendations for Mg, Zn, and Cu, respectively. Mean plasma concentrations were 0.85 +/- 0.004 mmol/L, 13.4 +/- 0.2 mumol/L, and 16.5 +/- 0.2 mumol/L for Mg, Zn, and Cu respectively. Mean 24-h urinary excretions were 5.7 +/- 0.2 mmol, 11.1 +/- 0.3 mumol, and 0.05 +/- 0.003 mumol, for Mg, Zn, and Cu, respectively. The data provided by the present study should be useful for comparing other physically active male populations.

Adult↗
PubMed1989

Zinc status of highly trained women runners and untrained women.

Endurance training effects on zinc status were assessed by comparing 13 highly trained (HT) and 10 untrained (UT) women. Blood and 24-h urine samples before and after a 25-mg oral Zn load, and 3-d dietary records were evaluated. Mean daily Zn intakes did not differ and were below the Recommended Dietary Allowances for both groups. Fasting concentrations of plasma Zn, serum albumin, alpha 2-macroglobulin, and erythrocyte Zn content did not differ. However, HT women had significantly (p less than 0.05) higher urinary Zn excretion (HT: 6.7 +/- 0.8 and UT: 4.5 +/- 0.7 mumol/d) and reduced responses to the oral Zn than did UT in terms of maximal responses (HT: 11.0 +/- 1.6 and UT: 16.2 +/- 1.2 mumol/L) and areas under the curve (HT: 34.8 +/- 2.7 and UT: 43.6 +/- 2.7 mumol.L-1.4h-1). The greater urinary Zn excretion by HT women may reflect higher rates of skeletal muscle turnover. Whether their reduced responses to the Zn load reflect differences in plasma volume, entry or removal of plasma Zn, or absorption is unknown.

Adult↗
PubMed1989

Red blood cell aggregation and sedimentation: the role of the cell shape.

The influence of erythrocyte shape changes on the sedimentation rate was studied in vitro and in vivo. In vitro the highest sedimentation rate was observed with a slight degree of stomatocytosis (morphological index-0.3; i.e. one red cell out of three being a stomatocyte I). With increasing degrees of stomatocytosis the sedimentation rate gradually decreased. Echinocytosis reduced the aggregation and sedimentation very drastically; the sedimentation rate was virtually zero when echinocytosis I or higher degrees were present. The influence of abnormal cell shapes occurring in vivo was studied in patients with an abnormal blood smear. It was found that a severely abnormal red cell morphology reduced the sedimentation rate in a standardized, fibrinogen-rich plasma to about half. These results indicate that the shape plays a crucial role in the aggregation and sedimentation of red cells and they may contribute to the understanding of the interaction of red cells with other cells such as endothelium.

Blood Sedimentation↗
PubMed1989

Prolonged whole-body cold water immersion: fluid and ion shifts.

To characterize fluid and ion shifts during prolonged whole-body immersion, 16 divers wearing dry suits completed four whole-body immersions in 5 degrees C water during each of two 5-day air saturation dives at 6.1 msw. One immersion was conducted at 1000 (AM) and one at 2200 (PM) so that diurnal variations could be evaluated. Fifty-four hours separated the immersions, which lasted up to 6 h; 9 days separated each air saturation dive. Blood was collected before and after immersion; urine was collected for 12 h before, during, and after immersion for a total of 24 h. Plasma volume decreased significantly and to the same extent (approximately 17%) during both AM and PM immersions. Urine flow increased by 236.1 +/- 38.7 and 296.3 +/- 52.0%, urinary excretion of Na increased by 290.4 +/- 89.0 and 329.5 +/- 77.0%, K by 245.0 +/- 73.4 and 215.5 +/- 44.6%, Ca by 211.0 +/- 31.4 and 241.1 +/- 50.4%, Mg by 201.4 +/- 45.9 and 165.3 +/- 287%, and Zn by 427.8 +/- 93.7 and 301.9 +/- 75.4% during AM and PM immersions, respectively, compared with preimmersion. Urine flow and K excretion were significantly higher during the AM than PM. In summary, when subjects are immersed in cold water for prolonged periods, combined with a slow rate of body cooling afforded by thermal protection and enforced intermittent exercise, there is diuresis, decreased plasma volume, and increased excretions of Na, K, Ca, Mg, and Zn.

Adult↗
PubMed1989

Erythrophagocytosis in the caprine hemal node.

Caprine hemal nodes were studied by transmission electron microscopy after glutaraldehyde fixation and epoxy resin embedding. Hemal node macrophages were observed to be engaged in erythrophagocytosis. In the early stages of endocytosis, intact erythrocytes were contained in some of the heterophagic vacuoles of macrophages. Later, granular, electron-dense material appeared on erythrocytes, presumably as a result of lysosomal degradation of their matrices. Subsequently, the matrix fragmented and probably formed 'myelin-like figures' and residual bodies that dominated the macrophage cytoplasm. In addition, images of sinusoidal endothelium, reticular cells, lymphocytes and, rarely, eosinophils were observed that depicted structures resembling various stages of lysosomal digestion of erythrocyte matrix noted in macrophages. Our study provides evidence to support the fact that effete erythrocytes are filtered, besides known organs, also in caprine hemal nodes. The morphology and location of hemal nodes suggest that the organ can be an efficient blood filter.

Animals↗
PubMed1989

Diagnostic dilemma of an unsuspected hyperfunctioning accessory parathyroid gland after total parathyroidectomy with autotransplantation in a peritoneal dialysis patient.

Persistent or recurrent hyperparathyroidism in patients with chronic renal failure may be a frustrating problem. We report a case history of a peritoneal dialysis patient who underwent total parathyroidectomy with autotransplantation for secondary hyperparathyroidism, developed tertiary hyperparathyroidism, and in an attempt to control hypercalcemia underwent seven partial resections of the autotransplant. Subsequently, a total excision of the parathyroid autograft was performed, but the patient continued to have hyperparathyroidism and unexpectedly was found to have a hyperplastic fifth parathyroid gland identified by thallium-technetium subtraction scan. The fifth gland was removed, and a part was implanted in the right forearm; however, the autoimplant had to be completely removed because of rapidly developing hypercalcemia. Hypercalcemia was controlled, but elevated levels of parathormone persisted. Remaining parathyroid tissue could not be found.

Female↗
PubMed1989

Relation between myocardial glutathione content and extent of ischemia-reperfusion injury.

The relation between the extent of myocardial injury sustained during reperfusion and total glutathione (GSH) content in the ischemic myocardium was examined in anesthetized open-chest pigs subjected to coronary occlusion for 45 minutes and reperfusion for 2 hours. In pigs infused with saline during reperfusion (n = 6) there was a decrease in myocardial GSH content from 380 +/- 48 micrograms/g in normally perfused myocardium to 182 +/- 36 micrograms/g in the ischemic reperfused myocardium (p less than 0.02). Myocardial infarct size (expressed as a percentage of the ischemic area) was 12.5 +/- 0.8%. There was a delay of recovery of contractile function before returning to 60% of preocclusion value. In pigs pretreated with buthionine sulfoximine (BSO) (n = 5), an inhibitor of cellular GSH synthesis, there was reduction in GSH content to 215 +/- 25 micrograms/gm in normally perfused myocardium and to 77 +/- 8 micrograms/gm in the ischemic reperfused myocardium. The extent of injury was greater as evidenced by an increase in infarct size to 30.4 +/- 4.0% (p less than 0.001), severe destructive changes in subepicardial ultrastructure, which were absent in saline-infused pigs, and persistence of dyskinesia throughout reperfusion. In pigs infused with glutathione intravenously (0.8 gm/kg) at a rate of 6.5 mg/kg/min (n = 6), 5 minutes before and continuously during reperfusion, there was an increase in GSH content to 582 +/- 67 micrograms/g in normally perfused myocardium and to 312 +/- 80 micrograms/g in ischemic reperfused myocardium. The increase in myocardial GSH was associated with a reduction in infarct size to 7.5 +/- 1.3% (p less than 0.05, compared with saline-infused pigs) and an early recovery of contractile function of the ischemic myocardium. GSH infusion into pigs pretreated with BSO (n = 4) failed to increase myocardial GSH content and failed to reduce the extent of myocardial injury. Thus, the extent of myocardial injury sustained during reperfusion is very dependent on the effectiveness of its antioxidant defenses. Markedly increased susceptibility to injury occurs when the GSH content in the ischemic myocardium becomes depleted.

Animals↗
PubMed1989

Ultrastructure of Sertoli cells in cryptorchid goats.

Sertoli cells of intra-abdominal testes from 25 naturally occurring, unilaterally cryptorchid, West African pygmy goats between the ages of 1-30 months were morphologically examined by light and transmission electron microscopy. Ultrastructurally, Sertoli cells in the intra-abdominal testes from 1-month-old goats were columnar and contained ovoid nuclei. The cytoplasm depicted clusters of rough endoplasmic reticulum cisternae (RER). In 3- to 4-month-old animals nucleolonemas of the Sertoli cells were associated with vesicles; the cytoplasm contained RER and areas of whorls of smooth endoplasmic reticulum. An abundance of lipid droplets was accompanied by lipofuscin granules in the cytoplasm. In 6- to 8-month-old goats RER cisternae presented circular or irregular profiles in the cells with an augmentation of cytoplasmic lipid droplets and lipofuscin granules. In 12- to 15-month-old animals intercellular spaces in the seminiferous epithelium exhibited focal expansions. Nuclear profiles of the Sertoli cells were irregular. In 24- to 30-month-old animals the Sertoli cells were in an advanced stage of degeneration.

Abdomen↗
PubMed1989

Human pharmacokinetics of samarium-153 EDTMP in metastatic cancer.

Samarium-153 ethylenediaminetetramethylene phosphonic acid ([153Sm]EDTMP) has been proposed to palliate pain resulting from osteoblastic metastatic bone cancer. Encouraging results in dogs with primary malignant bone cancer provided the catalysis for human biodistribution studies in five patients with metastatic skeletal carcinoma. The objective was to assess the preferential localization of [153Sm]EDTMP in bony lesions and compare it to the 99mTc-labeled phosphonates. Blood clearance of [153Sm]EDTMP was rapid with minimal accumulation in nonosseous tissues. Both radiopharmaceuticals showed identical lesion uptake in 23 paired lesions (p greater than 0.05). This indicates that the two radiopharmaceuticals concentrate in metastatic skeletal lesions by the same mechanism and since [153Sm]EDTMP emits beta radiation it may be therapeutically useful in ameliorating metastatic bony cancer pain.

Aged↗
PubMed1989

Pleiotropic changes in the activities of extracellular toxins of Pseudomonas aeruginosa protease-deficient mutants.

Protease-deficient mutants of Pseudomonas aeruginosa obtained by ethyl methane sulphonate treatment were found to show pleiotropic effect on various extracellular toxin activities. Of eight mutants five were completely deficient in lecithinase and four in collagenase activity. The decreased hemolytic activity was obtained in five mutants and enterotoxin activity in seven mutants as compared to parent strain.

Complement Hemolytic Activity Assay↗
PubMed1989

Ultrastructure of Sertoli cells in scrotal testis of unilaterally cryptorchid goat.

Electron microscopy revealed changes in Sertoli cells of the scrotal testes of unilaterally cryptorchid West African dwarf goats from neonate to maturity. The major changes included alteration of the cell shape due to proliferation of the spermatogenic cells, development of nucleolar vesicles and indentations of nuclear outlines, and profusion of smooth endoplasmic reticulum. These alterations are similar to those described for the differentiation of Sertoli cells in normal testis.

Animals↗
PubMed1989

Construction of a gene bank of Rhizobium leguminosarum Rld 164.

The total genomic DNA of R. leguminosarum Rld164 (trp, sms, azi) was cloned in the EcoR1 site of the wide host and conjugally transferable cosmid vector pLAFR1. The average insert size in the gene clones of the bank was found to be 21.3 Kb. The strain R. leguminosarum Rld7 (leu-1) was employed as recepient to conjugally transfer and thus isolate the complementary leu+ allele carrying clones from the gene bank.

Cloning, Molecular↗
PubMed1989

Carboxyhaemoglobin and serum cholesterol levels in smokers.

Carboxyhaemoglobin (COHb) and serum cholesterol levels were studied in twenty five chronic smokers, smoking different quantities of cigarettes, biris and "hooka" for more than ten years and compared with equal number of age and sex matched non-smoker controls. COHb levels were found to be significantly higher (P less than 0.001) in chronic smokers as compared to non-smokers while no significant difference (P greater than 0.1) was found in serum cholesterol levels between the two groups. Cigarette smokers had a higher COHb level as compared to biris smokers (P less than 0.001).

Adult↗
PubMed1989

Gall bladder disease: an analytical report of 250 cases.

Two hundred and fifty cases of biliary tract disease were studied as regards case history, physical and laboratory investigations, surgery and follow-up. It was found that females especially multipara were frequently affected; majority of cases were in 3rd to 5th decade of their life, rise in age showing decline in incidence. Majority of cases (82.4%) were vegetarians and had used vegetable fats (oriental diet). Most of the cases (98.8%) belonged to middle and poor class and were lean and thin. Pain in the right upper quadrant of the anterior abdominal wall had been the commonest symptom, in about half the cases it got aggravated by fatty meals. A mass was felt in the right hypochondrium in 29.6% and Murphy's sign was positive in 55.5% of cases. Radio-opaque calculi were present in 8% of cases, in another 10.8% the calculi were demonstrated by oral cholecystography, radiography could detect calculi in 47 (25.4%) cases and its overall diagnostic success rate has been low (56.8%). Ultrasonography proved more valuable tool for diagnosis; bile culture was positive in 8.8% of cases only for Esch coli, proteus, klebsiella, staphylococci or paracolon. Right subcostal incision gave the best results. Chronic cholecystitis with cholelithiasis (74%) was more common than acalculus cholecystitis (26%), incidence of carcinoma was 2.8%, and in 5 out of 7 cases malignancy was associated with cholelithiasis. Early diagnosis and cholecystectomy for gallstones can prevent malignancy. Surgery on the whole proved beneficial and it can be more rewarding if pre-operatively other causes of dyspepsia are either excluded or confirmed. Excluding cases of malignancy, the mortality has been quite low and thus acceptable.

Adolescent↗
PubMed1989

Chronic inflammatory polyarthritides in a select population of young men. A prospective study.

Twenty young servicemen suffering from chronic inflammatory polyarthritides (CIP) were studied. While rheumatoid arthritis (RA) was the final diagnosis in 15 patients, the arthritis remained 'unclassifiable' in the rest. An acute onset of asymmetric deforming arthritis, dominant in the lower limbs, was the usual pattern. Sacroiliitis and enthesopathy were uncommon. Extra-articular features were sparse and sub-cutaneous nodules absent. Rheumatoid factor was present in 86.7% of RA patients. Radiologic erosions were evident in 73.3% RA patients. Arthritis robustus variant of RA was diagnosed in 4 patients. HLA B27 was present in 45.5% of RA patients in this atypical setting. An overlap of RA and seronegative spondarthritides was considered probable in 3 patients.

Adolescent↗
PubMed1989

Alterations in acid-base status and blood gas dynamics during progressive hyperkalaemia in neonatal calves.

Alterations in acid-base status and blood-gas dynamics were studied during induced progressive hyperkalaemia in neonatal calves. The hyperkalaemia was associated initially with respiratory alkalosis in arterial blood when plasma K+ was increased to 6.08 +/- 1.02 mmol litre-1. The rise of plasma K+ above 6.08 +/- 1.02 mmol litre-1 led to the development of metabolic acidosis in arterial and venous blood. There was partial respiratory compensation. Plasma K+ concentrations at or above 11.03 +/- 0.34 mmol litre-1 were associated with a decrease in arterial oxygen tension and arterial oxygen saturation. The oxygen extraction ratio was increased during hyperkalaemia.

Acid-Base Equilibrium↗