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Biomedical subjects

A Chait

Publications and source records attributed to A Chait.

At least 163 records · Page 9Linked to original sources
PubMed1979

Infusion hepatotomography for evaluation of obstructive jaundice.

Total body opacification with high doses of a urographic contrast agent demonstrated dilated intrahepatic biliary ducts as branching or rounded lucencies in all of 18 patients with obstructive jaundice. Dilated extrahepatic ducts were seen as tubular lucencies in 11 of 16 patients with distal common bile duct obstruction. In seven patients with nonobstructive jaundice and in a control group of 25, the biliary ducts were either normal or not seen. Gallbladder size was also evaluated. The site of obstruction could be predicted by the size of the gallbladder and visualization of the biliary ducts.

Biliary Tract Diseases↗
PubMed1979

Low density lipoprotein receptor activity in fibroblasts cultured from diabetic donors.

Low density lipoprotein (LDL) receptor activity was evaluated in cultured skin fibroblasts from diabetics and nondiabetic controls to evaluate whether intrinsic abnormalities of the LDL pathway exist, which might account for the premature atherosclerosis associated with diabetes mellitus. LDL receptors did not differ between cells grown from 16 diabetics (7 insulin-dependent, 9 non-insulin-dependent ) or from 16 nondiabetic controls. An inverse relationship between LDL receptor activity and cell density was observed (y = 1.35x-1.22, r = 0.90, P less than 0.001), which appeared the same for diabetic and nondiabetic cells. Normalized values for LDL degradation by diabetic and nondiabetic cell strains were 1.52 +/- 0.42% of added LDL/10(6) cells and 1.34 +/- 0.28, respectively (P = NS). The kinetics of the LDL receptor also appeared to be the same in cells derived from a diabetic and a nondiabetic donor. LDL receptor activity in diabetic cells increased appropriately in response to physiologic concentrations of insulin in the incubation mediu. Thus, LDL receptor activity appears to be normal in diabetic cell strains. Therefore, these results do not support the possibility that alterations in the LDL pathway contribute to the accelerated atherosclerosis associated with diabetes.

Adult↗
PubMed1978

Regulatory role of insulin in the degradation of low density lipoprotein by cultured human skin fibroblasts.

The degradation of 125I-labeled low density lipoprotein by cultured human skin fibroblasts was enhanced 25% by preincubation of cells with insulin. This effect of insulin appeared to be mediated via stimulation of low density lipoprotein binding to its cell surface receptor, since binding and subsequent internalization of low density lipoprotein were stimulated to a similar extent as was degradation. In addition, insulin enhanced binding of low density lipoprotein at 4 degrees C, at which temperature internalization of the lipoprotein does not occur. A similar effect of insulin on the interaction of very low density lipoprotein with cultured fibroblasts was observed. Insulin-induced changes in the degradation of low density lipoprotein and very low density lipoprotein appeared to be a function of the change in lipoprotein binding. Thus, insulin may play a role in the regulation of low density lipoprotein and very low density lipoprotein degradation by peripheral cells by influencing the receptor-mediated transport of these lipoproteins.

Biological Transport, Active↗
PubMed1978

Impaired very low density lipoprotein and triglyceride removal in broad beta disease: comparison with endogenous hypertriglyceridemia.

The removal rate of apoprotein-B (apo B) in very low density lipoprotein (VLDL) was decreased in individuals with broad beta disease when compared with endogenous hypertriglyceridemia. Following the injection of 125I-VLDL isolated from individuals with endogenous hypertriglyceridemia, both VLDL apo B fractional catabolic rate (0.058 +/- 0.029 hr-1) and VLDL apo-B turnover rate (0.300 +/- 0.070 mg/kg/hr) were lower in broad beta disease than in endogenous hypertriglyceridemia (fractional catabolic rate 0.112 +/- 0.046, p less than .05; turnover rate 0.640 +/- 0.199, p less than .005) despite equivalent plasma concentrations of VLDL-apo-B. Furthermore, conversion of VLDL apo-B to LDL was impaired in broad beta disease relative to endogenous hypertriglyceridemia. Differences in the kinetics of lipoprotein lipase-related triglyceride removal during a maximal heparin infusion were also demonstrated between these two disorders. These differences suggest an abnormality in the interaction of lipoprotein lipase with the lipoproteins of unusual composition in broad beta disease. This is further supported by the normalization of lipoprotein composition in broad beta disease by estrogen therapy, with a simultaneous change in the kinetics of lipoprotein lipase-related triglyceride removal towards those seen in endogenous hypertriglyceridemia.

Adult↗
PubMed1978

Pathophysiology of lipoprotein transport.

A system for classification of genetic and acquired forms of hyperlipidemia in humans based on lipoprotein physiology is described. Most hyperlipidemia can be accounted for by defects in one of four sites of physiologic regulation: (1) triglyceride-rich lipoprotein production, (2) lipoprotein lipase-mediated triglyceride catabolism, (3) remnant lipoprotein catabolism, and (4) extrahepatic cholesterol-rich lipoprotein catabolism.

Apolipoproteins↗
PubMed1978

Serum lipoprotiens in four European communities: a quantitative comparison.

Serum lipid and lipoprotein concentrations have been measured in 985 men and women sampled from communities in London, Naples, Uppsala and Geneva. This was done to define normal ranges, detect inter-population differences, and relate such differences to levels of lipids in the major lipoprotein classes of plasma. Cholesterol and triglyceride concentrations showed substantial differences between the four populations; levels of these lipids showed parallel trends, which were attributable to differences in low density lipoprotein and very low density lipoprotein concentrations. By contrast, high density lipoprotein cholesterol concentrations showed little or no interpopulation differences. Geographical differences in serum triglyceride and cholesterol levels were not correlated with variation in the prevalence of obesity.

Adult↗
PubMed1978

The Dominican Republic conjoined twins: ischiopagus, tetrapus, omphalophagus.

Alta and Clara, the Dominican Republic conjoined twins (ischiopagus, omphalopagus, tetrapus) were evaluated prior to separation with plain films, vaginograms, arteriograms, intravenous pyelogram, barium enema, and upper gastrointestinal series with small bowel follow-through. The clear demonstration of their internal anatomy allowed the surgeons to plan the operative approach and to make a reasonable judgment regarding viability of each baby. Each twin had a semicircular pelvis which joined the other to form a complete ring. There were a few hepatic arterial twigs from Alta which crossed the midline, proving at surgery to be a small bridge of tissue connecting the two livers. Clara's superior mesenteric arteries supplied the majority of the small bowel. Portal venous drainage was separate for each twin. Each baby had two kidneys in normal position with the bladders laterally placed. Each bladder received one ureter from each twin. Two separate small bowels joined proximal to the single colon which terminated in an anus related to Clara's pelvic structures. Following separation, each baby did well. Their postoperative anatomy is described.

Dominican Republic↗
PubMed1977

Type-III Hyperlipoproteinaemia ("remnant removal disease"). Insight into the pathogenetic mechanism.

The metabolism of very-low-density lipoprotein (V.L.D.L.) was studied in a patient with type-III hyperlipoproteinaemia. After injection of radioiodinated V.L.D.L. from a donor with endogenous hypertriglyceridaemia (in a type-IV pattern), clearance of radioactivity from the apoprotein-B moiety of V.L.D.L. was slow and appearance in low-density lipoprotein (L.D.L.) was delayed, suggesting defective catabolism of V.L.D.L. in type-III hyperlipoproteinaemia. Despite a 60% increase in the rate of V.L.D.L. production, therapy with oestrogen (ethinyloestradiol 1 microng/kg/day) resulted in a decrease in plasma-lipid concentrations, normalisation of lipoprotein composition, and correction of the defect in V.L.D.L. catabolism with increased conversion to L.D.L. Thus, in type-III hyperlipoproteinaemia, the primary defect seems to be impaired catabolism of V.L.D.L., which is corrected with oestrogen therapy.

Apolipoproteins↗
PubMed1977

Type III hyperlipoproteinemia: paradoxical hypolipidemic response to estrogen.

Exogenous estrogens (ethinyl estradiol, 1 microgram/kg body weight per day), which stimulate triglyceride production in normal women and those with endogenous hypertriglyceridemia, were found to exert a paradoxical, hypolipidemic effect in six subjects (five women, one man) with type III hyperlipoproteinemia on diets both of normal and of fat-free, high-carbohydrate composition. Moreover, very low-density (VLD) lipoprotein lipid and apolipoprotein composition and electrophoretic mobility became normal during estrogen administration in these subjects. Levels of normal VLD lipoproteins remained mildly to moderately elevated in a type IV lipoprotein pattern. Estrogen withdrawal promptly restored the type III pattern with its abnormal enrichment of VLD lipoproteins with apolipoprotein E (the arginine-rich peptide). These findings suggest that estrogens facilitate the assimilation of chylomicron and VLD lipoprotein remnants, a defect that appears likely to represent the metabolic abnormality underlying type III hyperlipoproteinemia.

Adult↗
PubMed1976

Intravenous fat-tolerance test in ischaemic heart disease and peripheral vascular disease.

1. The intravenous fat-tolerance test and serum lipid and lipoprotein measurements were carried out in ninety-three normal subjects, fifty-one patients with ischaemic heart disease and thirty patients with peripheral vascular disease. 2. The fractional turnover rate of exogenous triglyceride was significantly slower in patients with ischaemic heart disease and in patients with peripheral vascular disease than in normal men. The rate was also slower in normal men than normal women. 3. Serum triglyceride and cholesterol concentrations were higher in both vascular disease groups than in control subjects. 4. The proportion of both groups of patients who had a subnormal fractional turnover rate of exogenous triglyceride was 35%, and 32% of patients had hypertriglyceridaemia in the fasting state; 27% of patients were hypercholesterolaemic. 5. Although the intravenous fat-tolerance test did not provide significantly better discrimination between cardiovascular patients and control subjects than did measurement of serum triglyceride, the results suggest that hypertriglyceridaemia in such patients may be separable into a group in which impaired triglyceride clearance may be partly responsible, and a group in which overproduction of serum triglyceride may be the major mechanism of the hyperlipidaemia.

Adult↗
PubMed1976

The internal mammary artery: an overlooked collateral pathway to the leg.

In 10 patients with an occluded aorta, angiography performed with the catheter in the abdominal aorta failed to opacify the reconstituted distal extremity arteries. Repeat injection into the thoracic aorta resulted in adequate opacification of the leg vessels through internal mammary-inferior epigastric artery collaterals. Moving the catheter from the abdominal aorta to the ascending aorta or selectively into the internal mammary artery is suggested when standard abdominal aortic injection fails to demonstrate runoff vessels.

Aortic Diseases↗
PubMed1975

Bromocriptine treatment of acromegaly.

The effects of oral bromocriptine in acromegaly have been studied. A dose of 5 mg six-hourly suppressed circulating growth hormone (GH) levels in nine out of 11 patients treated for seven to 11 weeks. This was associated with considerable clinical improvement in all patients, with abolition of excessive sweating, reduction in soft-tissue thichening, loosening of rings, decrease in shoe size, improvement in facial features, and loosening of dentures. Metabolic changes included improvement in glucose tolerance and reduction in hydroxyproline excretion. Unlike the actions of growth hormone release inhibiting hormone the suppression of GH was not accompanied by a reduction in insulin or glucagon secretion, though prolactin levels were suppressed. Side effects other than mild constipation were not seen when the full dose regimen was reached by slowly increasing the dose from 2-5 mg once daily. Bromocriptine holds promise as a safe and orally effective medical treatment to augment surgical or radiotherapeutic measures directed at the pituitary tumour. Its efficacy during longterm administration remains to be established.

Acromegaly↗
PubMed1975

The relationship between dietary fat composition and plasma cholesterol esterification in man.

1. Cholesterol esterification has been studied in the plasma of subjects on diets rich in saturated or polyunsaturated fat. 2. The diet rich in polyunsaturated fat was associated with lower rates of plasma cholesterol esterification in vitro. The data suggest that there was a reduction of plasma lecithin-cholesterol acyltransferase activity as well as decreased ability of the lipoprotein substrates of the enzyme to support esterification. 3. On this diet, there was no change in the proportion of the plasma cholesterol esterified but the plasma cholesterol and triglyceride concentrations were reduced.

Adult↗
PubMed1975

The specificity of renal vein thrombosis.

Clinical and roentgenographic features of renal vein thrombosis are discussed. The authors' experience with 17 cases is presented. The roentgenologist with a high degree of suspicion can, by correlation of clinical and urographic findings, make the specific diagnosis of renal vein thrombosis in a high percentage of cases.

Acute Disease↗
PubMed1974

Serum lipoprotein abnormalities in patients with ischaemic heart disease: comparisons with a control population.

The frequency and nature of abnormalities of serum lipoproteins have been studied, using quantitative techniques, in 143 patients with ischaemic heart disease (I.H.D.). Rigorous selection criteria were used. The findings were related to the distribution of lipoprotein concentrations in a carefully screened control population. Hyperlipoproteinaemia occurred in 55% of patients and in 11 out of 15 patients aged less than 40 years. Raised triglyceride and cholesterol concentrations in very low density lipoprotein were the most frequent abnormalities followed by raised cholesterol content of low density lipoprotein. In young patients high density lipoprotein levels were subnormal. Hyperlipoproteinaemia of W.H.O. types IIa, IIb, III, IV, and V all seemed to be over-represented in I.H.D. I.H.D. patients with type IIa, IIb, and IV abnormalities were all significantly younger than I.H.D. patients with normal lipoprotein levels.

Adult↗
PubMed1974

Experience with simplified scheme of treatment of hyperlipidaemia.

A series of 57 hyperlipidaemic patients have been investigated clinically and by measurement of cholesterol and triglyceride levels and inspection of stored serum. Two had secondary (alcoholic) hyperlipidaemia. Those with primary disorders were allocated to three groups believed to require different optimal therapy. At one year 51 of these 55 patients had lipid levels within a predetermined normal range and two others showed improvement. Despite the large number of primary hyperlipidaemic states our results suggest that in most patients successful treatment can be given according to simple classification into three therapeutic categories.

Alcoholism↗