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Biomedical subjects

E M Berry

Publications and source records attributed to E M Berry.

At least 91 records · Page 5Linked to original sources
PubMed1986

The relationship of dietary fat to plasma lipid levels as studied by factor analysis of adipose tissue fatty acid composition in a free-living population of middle-aged American men.

We have used adipose tissue biopsies to assess the quality of fat in the diet and its influence on plasma lipid levels in 413 free-living normolipidemic male subjects. Factor analysis identified three factors which separated the fatty acids on the basis of their chemical structure. F1--monounsaturates--animal fats; F2--saturates--carbohydrates; F3--polyunsaturates--vegetable oils. An increase in F1 was associated with an increase in plasma triglycerides (TG), plasma total cholesterol (TC), and VLDL-C: an increase in F2 led to a decrease in VLDL-C. A rise in F3 was associated with lowered TG, VLDL-C, and HDL-C but increased LDL-C. However, the contribution of each of these factors to the variance in TG, TC, LDL-C, and HDL-C was small, namely: 5.48, 1.30, 2.57, and 2.02%, respectively. A special relationship between F3 and VLDL-C was found such that 16.22% of its variance could be attributed to F3. Our conclusion is that adipose tissue composition and, by implication, the type of dietary fat intake, explains only a small proportion (1-19%) of the variance in plasma lipids in normolipidemic subjects.

Adipose Tissue↗
PubMed1986

Does dietary linolenic acid influence blood pressure?

Short-term intervention studies have shown that diets rich in polyunsaturated fats have hypotensive properties. We have studied the long-term effects of dietary fat on blood pressure (BP) using adipose-tissue, fatty acid composition analysis in 399 free-living male subjects (average age, 47 yr). Stepwise-regression analysis showed that adipose linoleic acid (18:2 n-6) was not associated with BP, whereas an absolute 1% increase in linolenic acid (18:3 n-3) was associated with a decrease of 5 mm Hg in the systolic, diastolic, and composite mean arterial BP. Linolenic acid (18:3) comprised only one-eighth the amount of linoleic acid (18:2)--the major polyunsaturate in adipose tissue and hence in the diet (2% vs 16%)--and yet it had a disproportionate association with BP. This may be related to its role as a precursor for the production of prostaglandins and/or other vasoregulators. Dietary manipulation with n-3 fatty acids may be helpful in the treatment and prevention of hypertension.

Adipose Tissue↗
PubMed1986

The role of dietary fat in human obesity.

Both the amount and quality of dietary fat have been implicated in the pathogenesis of obesity. Adipose tissue fatty and composition, which is known to reflect dietary intake, was sampled in 413 free-living, healthy American males appearing for a routine medical examination. The average age was 46.8 +/- 11.4 years (mean +/- s.d.) and body mass index (BMI)--weight/height--was 25.2 +/- 3.4. The BMI was correlated (P less than 0.01) with known risk factors for cardiovascular disease as follows: total cholesterol (TC) r = 0.18, triglycerides (TG) r = 0.32, low-density lipoprotein cholesterol (LDL-C) r = 0.18, high-density lipoprotein cholesterol (HDL-C) r = -0.24, systolic and diastolic blood pressure (BP) r = 0.30. Underlying patterns which might be related to diet were sought in the distribution of the seven major fatty acids in adipose tissue. Statistical analysis permitted delineation of three factors which were hypothetically related to animals fat intake (F1--monounsaturates), carbohydrate intake (F2--saturates) and vegetable oil intake (F3--polyunsaturates). F1 and F3 together accounted for 12 percent of the variance in BMI while F2 had no influence. Our conclusions are that the variance in BMI is related much more to non-dietary factors than to adipose tissue fatty acid composition and that the nature of dietary fat was not a major distinguishing factor in obesity in this population. There was also no evidence for a high dietary carbohydrate (low fat) intake in the obese.

Adipose Tissue↗
PubMed1986

Dietary fat, adipose tissue composition, and the development of carcinoma of the colon.

Dietary fat and plasma lipids have been implicated in the development of carcinoma of the colon. Because of the difficulties in obtaining accurate dietary histories, subcutaneous adipose tissue fatty acids were analyzed to compare fat intake in 3 groups of patients undergoing colonoscopy: patients with carcinoma of the colon (n = 53; average age, 64 yr; 47% male), patients with neoplastic polyps (n = 34; age 63 yr; 71% male), and patients with normal findings (controls; n = 68; age 58 yr; 40% male). The groups were similar with regard to body mass index and coffee and egg consumption. One-way analysis of variance of the plasma total cholesterol, triglycerides, high-density lipoprotein cholesterol, 9 adipose fatty acids, groups of polyunsaturated fatty acids (vegetable origin), saturated fatty acids (animal origin), or the ratio of polyunsaturated to saturated fatty acids did not show any significant differences across the 3 groups. The quality of dietary fat does not appear to be associated with the development of carcinoma of the colon or of neoplastic polyps in this population.

Adipose Tissue↗
PubMed1985

Alterations in adipocyte free fatty acid re-esterification associated with obesity and weight reduction in man.

Using a newly developed in vitro technique, the rate of re-esterification of lipolyzed free fatty acids (FFA) in small fragments of human subcutaneous adipose tissue was measured. When related to simultaneous glycerol release, this measure permits the calculation of the molar ratios of glycerol and FFA leaving the adipocyte. In weight-stable, never-obese control subjects the molar ratio of FFA:glycerol leaving the adipocytes is 1.4:1. During fasting, this ratio climbs to 2.7:1, close to the theoretical maximum of 3.0:1. Adipocytes from weight-stable obese subjects do not differ significantly from adipocytes of control in regard to this ratio. However, the adipocytes of weight-stable reduced-obese (RO) subjects display a significantly higher FFA:glycerol ratio than the adipocytes of either control or obese subjects. The presence of this fasting-like physiology in adipose tissue from weight-stable RO subjects is of particular interest since these same individuals have other systemic metabolic and subjective findings compatible with caloric deprivation.

Adipose Tissue↗
PubMed1985

Poststreptococcal neprhitis and acute rheumatic fever in two adults.

In two adult subjects who suffered acute episodes of rheumatic fever, sever kidney involvement developed with proteinuria and renal insufficiency. The clinical and histologic picture was typical of poststreptococcal (infectious) glomerulonephritis. During a follow-up period of more than three years, no clinical or biochemical abnormalities have been detected; thus, it is likely that both patients have recovered from their renal diseases. The coexistence of rheumatic fever and acute glomerulonephritis, which is uncommon even in your age groups, may be observed in adult subjects.

Acute Disease↗
PubMed1984

Radioisotopic method for the measurement of lipolysis in small samples of human adipose tissue.

To facilitate the study of adrenoreceptor response in small needle biopsy samples of human subcutaneous adipose tissue, we developed a dual radioisotopic technique for measuring lipolysis rate. Aliquots (20-75 mg) of adipose tissue fragments were incubated in a buffered albumin medium containing [3H]palmitate and [14C]glucose, each of high specific activity. In neutral glycerides synthesized in this system, [14C]glucose is incorporated exclusively into the glyceride-glycerol moiety and 3H appears solely in the esterified fatty acid. Alpha-2 and beta-1 adrenoreceptor activation of tissue incubated in this system does not alter rates of 14C-labeled glyceride accumulation, but does produce a respective increase or decrease in the specific activity of fatty acids esterified into newly synthesized glycerides. This alteration in esterified fatty acid specific activity is reflected in the ratio of 14C:3H in newly synthesized triglycerides extracted from the incubated adipose tissue. There is a high correlation (r = 0.90) between the 14C:3H ratio in triglycerides and the rate of lipolysis as reflected in glycerol release into the incubation medium. The degree of adrenoreceptor activation by various concentrations of lipolytic and anti-lipolytic substances can be assessed by comparing this ratio in stimulated tissue to that characterizing unstimulated tissue or the incubation medium. This technique permits the study of very small, unweighed tissue biopsy fragments, the only limitation on sensitivity being the specific activity of the medium glucose and palmitate. It is, therefore, useful for serial examinations of adipose tissue adrenoreceptor dose-response characteristics under a variety of clinical circumstances.

Adipose Tissue↗
PubMed1981

Lipoprotein secretion by isolated perfused livers from streptozotocin-diabetic rats.

In liver perfusion from sucrose-fed, streptozotocin-diabetic rats there was in comparison with normal animals, a decrease in very low density lipoprotein concentration in the perfusion medium (38.6 +/- 6.3 versus 64.4 +/- 8.4 microgram . g liver -1 3 h-1, p less than 0.05) and an increase in high density lipoprotein concentration (33.5 +/- 6.5 versus 14.0 +/- 1.9 microgram . g liver-1 3 h-1, p less than 0.005), which was paralleled by enhanced secretion of apoprotein A-I. The triglyceride: protein ratio was lower in very low density lipoprotein from diabetic animals (8.8 versus 13.4). Analysis of the apoprotein composition showed that diabetic very low density lipoprotein lacked arginine-rich protein (apo-E) and apo-C peptides; diabetic high density lipoprotein also lacked arginine-rich protein but contained more A-IV and apo-C-peptides. This may indicate net transfer of C peptides to high density lipoprotein from the degradation of very low density lipoprotein particles. The ratio of 3H-leucine: 14C-glucosamine incorporation was decreased in all diabetic lipoprotein classes suggesting increased glycosylation of apoproteins. These changes in particle composition may influence lipoprotein metabolism in diabetes through their effects on lipoprotein lipase and lecithin cholesterol acyl transferase activity, plasma half-life and tissue binding.

Animals↗
PubMed1981

Role of the liver in the degradation of very low density lipoproteins: a study of lipolysis by heparin releasable liver lipase and uptake during isolated rat liver perfusion.

The role of the liver and of a heparin-releasable liver lipase in the metabolism of very low density lipoprotein (VLDL) was investigated in vitro and during recycling rat liver perfusion. Rat plasma VLDL and nascent hepatic VLDL were labelled biosynthetically in their lipid moieties. Incubation in vitro of VLDL with the lipase caused hydrolysis of VLDL-triglycerides (greater than 80%) and VLDL-phosphatidylcholine (greater than 30%). Nascent VLDL was a better substrate for the enzyme. The hydrolytic activities were inhibited by 70--90% when rat plasma (10--30 vol%) was added to the incubation mixture. VLDL-triglycerides and cholesterol esters were taken up by the liver during 180 min recycling perfusion. The rate of disappearance of nascent VLDL was faster than that of plasma VLDL (half-life times of 56.2 +/- 13.9 and 125.0 +/- 24.8 min respectively). Injection of heparin into the perfusion medium caused accelerated uptake of the hydrolysed VLDL-triglyceride by the liver. Addition of plasma (d greater than 1.006 g/ml) to the perfusion at a concentration of 10 vol% delayed the rate of disappearance of VLDL from the perfusate by about 50--75%. These studies have established the capacity of the hepatic lipase to hydrolyse VLDL-lipids and the ability of the liver to degrade nascent and plasma VLDL particles. These two activities, however, are depressed by plasma and therefore previous studies of VLDL metabolism may have to be re-examined when based on incubations or perfusions in the absence of plasma.

Animals↗
PubMed1981

Enteral administration of insulin in the rat.

1 The effect of the surfactant, Cetomacrogol 1000, on the absorption of insulin across the rectal mucosa has been studied. 2 Rectal administration of microenemata containing Cetomacrogal 1000 and insulin causes a rise in the plasma concentration of insulin and a consequent fall in the blood glucose concentration in diabetic and non-diabetic rats. 3 The hypoglycaemic response is dependent on both the concentration of surfactant and the dose of insulin administered. 4 The results suggest that the transport of insulin across the rectal mucosa is facilitated by Cetomacrogal 1000.

Animals↗
PubMed1980

Protein and glycoprotein synthesis and secretion by the diabetic liver.

Protein and glycoprotein synthesis and secretion by isolated perfused livers and isolated hepatocytes from control and streptozotocin diabetic rats have been investigated. (3)H-Leucine and (14)C-glucosamine incorporation were used as markers for protein and glycoprotein synthesis and secretion. Total protein secretion was reduced by 50% in the perfusate (p < 0.001) and by 36% in hepatocytes (p < 0.05), but glycoprotein secretion was unchanged in both preparations from diabetic animals. These differences were not due to changes in the available pool sizes of the different labels. On liver fractionation, all membrane components from the liver of diabetic animals had lowered (3)H-leucine: (14)Cd-glucosamine ratios in relation to the control animals. This was caused by enhanced glucosamine incorporation in relation to that of leucine. It is suggested that whereas protein synthesis is decreased in acutely diabetic rats, the production of glycoproteins is normal and occurs by the same pathway as in control animals.

Animals↗
PubMed1980

Malabsorption following aorto-femoral bypass.

A case of malabsorption which developed after aortofemoral bypass surgery is described. Barium enema showed ischemic changes, and postoperative arteriography revealed marked reduction of the peripheral vascular bed of the mesenteric arteries. Malabsorption probably developed as a consequence of mesenteric ischemia, aggravated by the surgical procedure, the so-called aorto-iliac steal syndrome.

Aged↗