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Biomedical subjects

A Moran

Publications and source records attributed to A Moran.

143 records · Page 8Linked to original sources
PubMed1982

Na+-dependent hexose transport in vesicles from cultured renal epithelial cell line.

Apical membrane vesicles were prepared from cultured epithelia formed by LLC-PK1 cells using a calcium precipitation technique. alpha-Methylglucoside uptake into this vesicle preparation was markedly stimulated by sodium and inhibited by phlorizin. In addition, a transient "overshoot" of intravesicular alpha-methylglucoside concentration above its equilibrium value was observed under initial sodium gradient conditions. The specificity of this sodium-dependent hexose transporter closely resembled that found in the mammalian kidney brush border membrane, e.g., alpha-methylglucoside, D-glucose, and D-galactose apparently share the transporter while 2-deoxy-D-glucose, mannose, and fructose do not. Kinetic analysis of the sodium-dependent component of alpha-methylglucoside flux into LLC-PK1 apical membrane vesicles indicates the existence of single transporter with Km congruent to 2 mM and Vmax congruent to 3 nmol.min-1.mg protein-1. Measurement of alpha-methylglucoside uptake as a function of sodium concentration is consistent with a sodium:sugar stoichiometry of approximately 2:1.l There is a good correlation over time between the development of the concentrating capacity of the intact epithelium for alpha-methylglucoside and the transport properties of the vesicle preparation.

Animals↗
PubMed1982

Heterogeneity of sodium-dependent D-glucose transport sites along the proximal tubule: evidence from vesicle studies.

The glucose transport properties of brush border membrane vesicles from the outer cortex (early proximal tubule) and outer medulla (late proximal tubule) of rabbit kidney were studied. In the outer cortical preparation the behavior of the sodium-dependent component of D-glucose flux indicated the presence of a low-affinity transport system with Km congruent to 6 mM and Vmax congruent to 10 nmol.min-1.mg protein-1 as measured under zero trans conditions at 40 mM NaCl and 17 degrees C. By contrast, in the outer medullary preparation this component of flux behaved as a high-affinity system with Km congruent to 0.35 mM and Vmax congruent to 4 nmol.min-1.mg protein-1. Differences in transport specificity between the two preparations were also indicated and glucose uptake by the outer cortical vesicles was significantly more sensitive to inhibition by phlorizin. These results suggest the existence of two distinct sodium-dependent D-glucose transport systems in the renal proximal tubule brush border membrane. The kinetic studies presented here were done under zero trans sodium and glucose conditions. The rationale and methodology for carrying out these measurements reliably are discussed in detail.

4-Nitrophenylphosphatase↗
PubMed1980

Alveolar Pco2 during rest and exercise in divers and non-divers breathing O2 at 1 ATA.

The extent of hypercapnia in oxygen-breathing subjects was investigated during rest and exercise (650 kpm/min). Divers, ex-divers, and non-divers were studied. Carbon dioxide retention was judged by end-tidal Pco2 values achieved after a few minutes at each state. End-breath-hold (EBH) PAco2 was also measured in the two states to assess the contribution of breathing pattern to CO2 retention. Findings indicated a pronounced hypoventilation and hypercapnia in the divers during exercise, and a mean exercise EBH PAco2 value 15 mmHg greater than that in non-divers. Ex-divers had group mean values not significantly different from those of active divers. Superimposed inspired CO2 load caused similar elevations in PAco2 values in divers and non-divers. We concluded that CO2 retention in exercising oxygen-breathing divers cannot be accounted for solely as a conditioned breathing behavior, may be due partly to a reduced central responsiveness of CO2, and is not dependent on current diving activity.

Adolescent↗
PubMed1976

Survey of dental needs and estimated cost of dental care of a disadvantaged university population.

At the University of Connecticut, 115 disadvantaged students received dental examinations. There was a significant need for emergency dental care. The estimated cost of dental services for this group averaged $318.62 per student. The dental needs of disadvantaged and minority as well as all university students, should be addressed and services should be provided at least for needs of acute nature.

Adolescent↗
PubMedDate not supplied

An evaluation of diabetes knowledge amongst general practitioners and senior medical students. Central Manchester Health Authority Working Party on Diabetes Care.

Knowledge about diabetes, its management and its complications was assessed using a questionnaire sent to 80 Central Manchester general practitioners (GPs) and 192 senior medical students. Completed questionnaires were received from 57 GPs and all medical students. Eight GPs had already established mini-clinics and a further 10 expressed interest in starting such a clinic. GPs scored 60 (38-83) % in the test whereas students had a mean score of 50 (26-77) % (p less than 0.001). Deficiencies in knowledge were detected in the following areas: the management of insulin-treated patients during acute illness, indications for insulin therapy in Type 2 diabetes, and several aspects of dietary management. This survey has demonstrated a considerable interest in diabetes amongst GPs, with a response rate of 71%, and one in three of those who responded were interested in establishing clinics. Should these results be representative of GPs elsewhere, this would suggest the need for a postgraduate course on diabetes in general practice, and emphasizes the necessity of close cooperation between hospital and general practice in diabetes care.

Diabetes Mellitus↗
PubMedDate not supplied

Glycemic response to dietary supplements in cystic fibrosis is dependent on the carbohydrate content of the formula.

BACKGROUND: Enteral formula feedings are frequently prescribed to cystic fibrosis (CF) patients to boost caloric intake. A substantial number of these patients are glucose intolerant and have severe respiratory compromise. METHODS: To determine the effect of the carbohydrate content on glucose tolerance and respiratory function in glucose-intolerant CF patients with poor lung function, we examined the response to bolus feedings of five dietary supplements; a high-fat formula developed in our Clinical Research Center (CRC), Pulmocare, a high-carbohydrate formula developed in our CRC, Ensure Plus, and sugar-free Scandishake. RESULTS: Glucose excursion in response to the formulas with the lowest carbohydrate content was significantly less than that found in response to formulas with higher carbohydrate content. Insulin levels were also markedly lower in response to the low-carbohydrate high-fat formulas. Glucose excursion, expressed as a percent of the response to the CRC high-fat formula, was 111% +/- 12% for Pulmocare (p = NS), 202% +/- 34% for Ensure Plus (p < 01), 227% +/- 37% for CRC high carbohydrate (p = .001), and 357% +/- 33% for sugar-free Scandishake (p < .001). CO2 production, O2 consumption, minute ventilation, and respiratory rate increased modestly but not significantly in response to all formulas. No significant differences were found between the formulas in regards to these parameters. There were no subjective complaints of dyspnea during any of the five studies. CONCLUSION: The carbohydrate content of liquid dietary supplements appears to be an important determinant of hyperglycemia in glucose-intolerant adult CF patients.

Adult↗
PubMedDate not supplied

Renal cells in culture as a model for cystinosis.

The established renal cell line LLC-PK1 was used as a model to investigate the mechanism underlying kidney malfunction observed in cystinosis patients. In this disease lysosomal accumulation of cystine impairs kidney function, and glycosuria is an early clinical manifestation. The linkage between lysosomal accumulation of cystine and impairment of kidney function is still unclear, and no animal model is available. In an attempt to gain a better insight into this relationship, we studied the effects of lysosomal loading with cystine on the survival and functions of normal noncystinotic renal epithelial cells (LLC-PK1), nonrenal fibroblasts (NIH-3T3), and cystinotic fibroblasts (GM2837). Incubation of the cells with cystine dimethylester (CDME) resulted in time- and dose-dependent accumulation of cystine, with 80% of the cystine in the lysosomal fraction. The lysosomal concentration of cystine increased in the three cell lines after 3 hours of incubation and declined significantly after 48 hours in the normal, but not cystinotic, cells. The accumulation of cystine in the lysosomes caused dose- and time-dependent cell mortality, assessed by measuring the activity of the cytosolic enzyme, lactic dehydrogenase, in the medium. Survival of fibroblasts and renal cells was similar in all three cell lines. The concentrating capacity (the ratio fo the intra- and extracellular concentrations) of the nonmetabolized sugar analog, alpha methyl glucoside (AMG), was used to assess the function of the kidney cells. The sugar concentrating capacity of LLC-PK1 cells was reduced after incubation with CDME in a dose- and time-dependent manner. Since there was no change in sugar efflux between the untreated and treated cells, we conclude that an impairment of the uptake of AMG is responsible for the reduction in the sugar-concentrating capacity in LLC-PK1 cells. In the absence of a genetically impaired animal model, LLC-PK1 cells treated with CDME can be used to investigate the cellular mechanisms responsible for the impairment of kidney function in cystinotic patients.

Alanine↗
PubMedDate not supplied

Colonic metastasis of breast carcinoma.

Metastasis of breast carcinoma to the colon is a rare occurrence. We report here the case of a 65-year-old patient who presented a stenosing tumor of breast origin, located in the right colon. Some of the regional lymph nodes were infiltrated but no distant metastasis were detected. The primary breast lesion was a 4-cm infiltrating adenocarcinoma, operated 4 years earlier. Surgical removal of the lesion was followed by Endoxan-Epirubicin and 5-Fluororacil chemotherapy and the patient remained disease-free during the 3 years of follow-up. We could find only 2 similar cases reported in the world literature until now. Profound anemia in a patient with a past history of breast carcinoma may indicate colonic metastasis; treatment should be surgery followed by chemotherapy.

Adenocarcinoma↗