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Biomedical subjects

G Enzi

Publications and source records attributed to G Enzi.

At least 91 records · Page 5Linked to original sources

Metabolic abnormalities in multiple symmetric lipomatosis: elevated lipoprotein lipase activity in adipose tissue with hyperalphalipoproteinemia.

Lipoprotein lipase activity in lipomatous tissue, post-heparin lipoprotein lipase activity in plasma, and the composition and concentration of serum lipoproteins were studied in 15 patients with Multiple Symmetric Lipomatosis (MSL). Extremely elevated lipoprotein lipase activity in adipose tissue was found in MSL patients. Total and hepatic post-heparin plasma lipolytic activity was normal, while a moderate but statistically significant increase of extrahepatic lipolytic activity was present. An abnormal composition of serum lipoproteins, characterized by a significant increase in high density lipoproteins, namely HDL2 subfraction, and apoprotein A-I, was demonstrated. A concomitant decrease in and abnormal composition of low density lipoproteins were found. This lipoprotein pattern is consistent with a newly recognized type of hyperalphalipoproteinemia. Significant correlations were found between serum HDL2 cholesterol values and lipoprotein lipase activity in adipose tissue (as well as between serum VLDL-triglyceride and HDL2 cholesterol values). These observations confirm the role of adipose tissue lipoprotein lipase in triglyceride-rich lipoprotein catabolism. The elevated levels of lipoprotein lipase activity in adipose tissue, in addition to a previously demonstrated decrease in adrenergic-stimulated lipid mobilization, could account for both the abnormal fat accumulation in lipomatous fat cell and for hyperalphalipoproteinemia in MSL patients. The occurrence of MSL in two brothers suggests an inherited enzymatic defect, indicating MSL as a "triglyceride storage disease in adipose tissue".

Adipose Tissue↗

Postnatal development of adipose tissue in normal children on strictly controlled calorie intake.

The relations between adipose tissue development at birth, later expansion of fat mass and the behavior of fat mass and fat cell growth from birth to 12 mo of age have been studied in normal children born to normal, obese or diabetic mothers and maintained on strictly controlled calorie intake. A simple method for fat cell size determination on microsamples of fat tissue, specifically designed for small children, is reported. In the first 3 mo of life, a marked increase of fatty tissue from 13.4 +/- 0.4 to 20.3 +/- 0.8 percent of total body mass was observed. Subsequently, a sharp decrease in the relative amount of fat mass occurs, probably related to an increased energy expenditure or to a slightly higher protein content in the diet. No sex related differences in body weight, body fat mass, sum of skinfold thickness or fat cell weight were found throughout the study. No significant differences in body fat mass, sum of skinfold thickness and body fat mass as percent of body weight was observed at birth and at 3 or 6 mo of age in children of obese or gestational diabetic mothers, in comparison with children of normal mothers, and no significant correlation was found between maternal adiposity (sum of skinfold thickness or pre-gravidic overweight) or glucose tolerance (blood glucose area after OGTT) and adipose tissue development in the first 6 mo of life. Thus, in children on strictly controlled intake, obesity or diabetes in the mother do not relate to the rate of fat accumulation. Moreover, no relations were found between adipose tissue development at birth and subsequent rate of fat enlargement in the first year of life. Thus, when the interference of a different calorie intake is excluded, adiposity at birth has no predictive value for possible fatness later in infancy.

Adipose Tissue↗

Computed tomography of deep fat masses in multiple symmetrical lipomatosis.

Deep fat masses were evaluated by computed tomography (CT) in 15 patients with multiple symmetrical lipomatosis. In 4 patients, peritracheal accumulations of fat were observed. In 3 of them, tracheal compression by lipomatous tissue was demonstrated: 2 were asymptomatic and the third had severe respiratory insufficiency secondary to blockage of the airway by the vocal cords as the result of recurrent nerve palsy. In 6 patients, lipomatous tissue occupied the potential space between the spinal scapulae and the trapezius, supraspinatus, and infraspinatus muscles. In 2, calcification of lipomatous masses was observed. There was no relationship between extension of subcutaneous fat and accumulation at deep sites. CT facilitates early detection of peritracheal lipomatous tissue and is helpful in follow-up when deep fat accumulation is responsible for space-occupying lesions requiring surgery.

Adult↗

Intrauterine growth and adipose tissue development.

Body fat mass (BFM), skinfold thickness (ST), and fat cell weight (FCW) have been studied in 86 newborn infants with different maturity and different intrauterine growth, and in parabiotic twins. Preterm infants (35.5 +/- 0.4 wk) with body weight appropriate for gestational age had lower values of BFM and sum of ST as compared to the control group, without differences in FCW (0.23 +/- 0.03 versus 0.22 +/- 0.02 micrograms). In infants born between 30 and 41 wk of gestation with body weights at birth appropriate for gestational age, ST and BFM progressively increase with gestational age, while the FCW remains constant. These observations suggest that fat mass growth in the last 2 months of fetal life, essentially depends on fat cell replication. In full-term large-for-date babies, bFM resulted significantly greater than in controls both in absolute values (p less than 0.001) and in percentage values of total body weight (p less than 0.001). The FCW in large for date newborns resulted significantly greater than in controls (0.50 +/- 0.06 versus 0.22 +/- 0.2 micrograms, p less than 0.001). In full-term small-for-date newborns BFM, ST, and FCW resulted significantly lower than in controls (p less than 0.001). In full-term newborns with different body weight at birth, fat cell weight was correlated to BFM (r = 0.67; p less than 0.01), to BFM as percentage of body weight (r = 0.67; p less than 0.001) and to ST (r = 0.73; p less than 0.001). In three couples of identical parabiotic twins, the larger baby of every pair showed even greater values of BFM, ST, and FCW and fat cell weight than the respective sibling. These observations suggest that in newborns with different intrauterine growth, a different triglyceride content in single adipocytes largely explains the variations in fat mass development.

Adipose Tissue↗

Altered surfactant synthesis and function in rats with diet-induced hyperlipidemia.

Altered lung function in hyperlipidemic patients has been reported by many authors. An alteration of surfactant synthesis has been suggested. Isolated lungs of rats rendered hyperlipidemic by suitable diets display an increased distensibility at maximal inflation and a higher degree of alveolar stability during deflation. These alterations are related to modifications of surfactant properties. Lung lavage fluid obtained from hyperlipidemic rats displays an increase in percent content of phosphatidylglycerol and a decrease of phosphatidylethanolamine. The percent content of phosphatidylglycerol correlates with the circulating levels if free fatty acids (FFA). It is suggested that FFA might affect the activity of enzymes operating in lung phospholipid synthesis. The reported increase of surfactant phosphatidylglycerol might explain the increment of alveolar stability observed in hyperlipidemic rats.

Animals↗

Effects of refeeding on adipocyte metabolism in the rat.

Glucose metabolism in fat cells from fasted-refed rats and ad-libitum-fed controls were studied in the postabsorptive state. Two types of experiments were performed. First, each rat donated one epididymal fat pad and the metabolic results were expressed in relation to the number and size of fat cells of these tissues. Second, the other epididymal fat pad in the rats in each experimental group was pooled for experiments in duplicate where liberated fat cells were separated in fat-cell size classes, which enabled comparisons of metabolic activities at the same fat-cell size. Glucose incorporation into carbon dioxide and triglyceride glycerol and fatty acids were about equally elevated in absolute terms in the refed rats. In relative terms the increase was much more pronounced in carbon dioxide and fatty acids because these activities were very low in control rats. These results confirm previous results showing elevated metabolism after fasting-refeeding, and also demonstrate that this is an adaptation of fat-cell metabolism rather than a consequence of a higher cellular density of adipose tissue after fasting-refeeding with smaller fat cells. Adaptations of metabolism after fasting-refeeding might be of potential importance for elucidation of the cause of the rapid relapse after weight decrease of obese subjects with diminished fat-cell size.

Adipose Tissue↗

Effect of a hydrophilic mucilage in the treatment of obese patients.

A crossover study was carried out in 22 obese patients to evaluate the effect of a hydrophilic mucilage associated with a 800 calorie hypoglucidic diet, as compared to diet alone, on body weight and on plasma lipid levels. The administration of mucilage resulted in a weight loss greater than that obtained with diet alone. Moreover, plasma cholesterol and triglyceride level reduction was more pronounced in the patients on mucilage treatment. While reduction in plasma triglyceride levels was correlated to variations in body weight, reduction in cholesterol levels was not. This fact may be explained by reduced intestinal absorption of bile acids, as suggested by the significant reduction in plasma bilirubin levels observed in patients on mucilage treatment. During the first period of treatment with mucilage, a slight reduction in plasma levels of iron and calcium was observed, without modifications in red blood cell counts, haematocrit values and haemoglobin concentration. In 6 patients on protracted treatment (6 months), no further modifications in serum iron and calcium levels were observed.

Adult↗

Effect of lipid loading on fetal uptake of free fatty acids, glycerol, and beta-hydroxybutyrate.

The possibility of influencing the fetal uptake of free fatty acids (FFA), beta-hydroxybutyrate (beta-OH), and glycerol was demonstrated by enhancing the maternal blood level of these substances by means of 10% intralipid infusions to the mothers during delivery. The FFA uptake, which was not significant in fetuses of control mothers, became positive in fetuses born after maternal infusion with intralipid. The uptake of beta-OH and glycerol, which were positive in normal conditions, increased in fetuses from intralipid-infused mothers. These studies demonstrate that, after intralipid infusions to the mothers, the fetal FFA uptake could be correlated with the FFA concentration difference between maternal arterial, and fetal umbilical arterial blood. Since the fetal uptake of FFA subsequent to intralipid infusions is not negligible, we consider the possibility that lipid infusions to the mothers could be an approach to the treatment of the fetus with poor intrauterine growth.

Blood Glucose↗

Multiple symmetric lipomatosis: a defect in adrenergic-stimulated lipolysis.

The cellularity of normal and lipomatous adipose tissue and its response to different lipolytic agents have been studied in a group of 10 patients with multiple symmetric lipomatosis (MSL). In MSL patients, fat cells from lipomatous tissue are smaller than normal, uninvolved adipocytes. Fat cells from lipomata show minimal variations in size following conspicuous increase of lipomatous masses. These findings suggest that the growth of lipomata can be attributed to the neoformation of adipocytes rather than to an enlargement in the single fat cells. The incidence of reduced glucose tolerance and of hyperlipoproteinemia is similar in MSL patients and in controls. A significant reduction in plasma free fatty acids was observed in MSL patients after a 24-h fast as well as after noradrenaline infusion. A specific insensitivity of lipomatous tissue to the lipolytic effect of noradrenaline and isoprenaline was observed in vitro, as indicated by glycerol release in the medium, whereas response to theophylline and to dibutyryl cyclic AMP was retained. The lipolytic response to catecholamines was retained. The lipolytic response to catecholamines was normal in the nonlipomatous adipose tissue of MSL patients. In basal conditions ATP concentrations were similar in normal and in lipomatous adipose tissue. However, incubation with noradrenaline induced a significant fall in intracellular ATP levels in normal tissue, whereas no variations were observed in lipomatous tissue. Theophylline, instead, induced a prompt and significant decrease in intracellular ATP levels in lipomatous tissue. These observations indicate that the block in catecholamine-stimulated lipolysis in lipomatous tissue of MSL patients can be localized at a level preceding the formation of cyclic AMP.

Adenosine Triphosphate↗

[Clinical and metabolic aspects of juvenile myocardial infarct].

A clinical and metabolic study of 61 patients with myoocardial infarct before the age of 40 yr showed a high frequency of familial involvement, particularly in subjects with type IIA and IIB hyperbetalipoproteinaemia. Excess weight and arterial hypertension were rare, while premonitory angina was absent in 59%. Four subjects were diabetic. Oral glucose tolerance was normal in 14 and of diabetic type in 26 of 40 patients examined; the insulin response pointed to insulin-resistance. Dyslipidaemia was noted in 45%, including type IIA and IIB hyperbetalipoproteinaemia in 27%. Distribution of the frequency of infarct in function of cholesterolaemia classes gave a bimodal curve indicative of distinct normo- and hypercholesterolaemic groups within the series. Reduced glucose tolerance was more frequent in patients with low blood cholesterol. This suggests that reduced tolerance and high blood cholesterol are independent risk factors in coronary disease. No relation between the clinical and metabolic data could be ascertained.

Adult↗

Short-term and long-term clinical evaluation of a non-amphetaminic anorexiant (mazindol) in the treatment of obesity.

The effectiveness and tolerance of a non-amphetaminic anorexiant drug has been evaluated in a short-term and in a long-term clinical trial in simple obesity and in refractory obesity. In the short-term 'crossover' trial, a more evident effectiveness and tolerance result when the anorexiant is given in a late phase of treatment. The association of an anorexiant drug with the hypocaloric diet was seen to be effective in the treatment of so-called refractory obesity. In the evaluation of the long-term treatment it is seen that weight loss is greater and remains so farr longer periods in patients receiving anorexiant, as compared to controls. This is related to a better maintenance of a restricted calorie regimen. Mazindol did not affect the improvement of glucose tolerance and insulin secretion which follows the weight reduction.

Adolescent↗