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Biomedical subjects

O Bosello

Publications and source records attributed to O Bosello.

At least 73 records · Page 4Linked to original sources
PubMed1991

Influence of weight reduction on plasma high-density-lipoprotein cholesterol concentrations in severe obesity: interrelationships with plasma insulin levels.

The influence of caloric restriction and of weight loss during a weight-maintaining diet on lipid profile and in particular on high density lipoprotein (HDL) is controversial. In this study we analyzed the effect of a period of very low caloric diet (VLCD) and of a period of hypocaloric diet followed by 30 days of weight stabilization on lipoprotein levels, especially on HDL cholesterol and its subfractions (HDL2 and HDL3) and on the summated means of glucose (sigma glucose) and insulin levels (sigma IRI) after an oral tolerance test in a group of obese females. Body weight decreased significantly during the VLCD and hypocaloric diet. Total cholesterol decreased significantly after the VLCD and hypocaloric diet, but after the period of the weight-maintaining diet it was superimposable to the initial value. Very low density lipoprotein (VLDL) and low density lipoprotein (LDL) cholesterol behaved like total cholesterol. HDL2, HDL3 and HDL cholesterol decreased significantly after the period of VLCD. Then, after the hypocaloric diet the values of HDL2, HDL3 and HDL cholesterol returned towards the initial values and only after the period of the weight-maintaining diet did their values increase significantly. sigma glucose did not vary significantly at any time of the study, while sigma IRI reduced significantly both after the hypocaloric diet and the weight-maintaining diet. HDL2 and HDL cholesterol changes were found to be positively correlated to the variations of sigma IRI both at day 45 and 75 of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Italian Consensus Conference--overweight, obesity and health.

On 5 and 6 April 1991, at the National Research Council (CNR) in Rome, a Consensus Conference on the relationship between overweight, obesity and health was held. The conference was sponsored by FATMA (Applied Project on Disease Factors of the CNR) and UICO (Italian Society for the Study of Obesity) with the purpose of establishing guidelines for health employees. The development of the conference followed the methodology set down by OMAR to obtain a rational and significant consensus on the answers to six basic questions prepared by the planning committee. The questions were the pivotal point of the conference and were brought to the attention of all the attendees and widely diffused among the medical community; they were proposed with the aim of giving an exhaustive definition of obesity, to investigate its relationship with mortality and morbidity, to highlight its social characterization, to indicate methods of evaluation and recommendations for weight loss, to select groups at risk, and to focus general guidelines for research. After the presentation of the state of the art on 18 topics by experts in the field, the 22 members of the consensus panel, impartial experts from a vast area of the scientific community, discussed a draft document representing the answers to the questions, which was subsequently submitted to the 307 attendees, discussed and then approved. This paper is the definitive document of the Consensus Conference. The introduction explains the reasons which led to the decision to promote the conference six years after the one held in the United States. The methodology is then set out. The questions are answered in the form of recommendations and backed up by data and scientific evidence from the literature.

Body Weight↗
PubMed1991

Sonography detection of small intra-abdominal fat variations.

The aim of this study was to check the reliability of sonography in measuring small variations in quantities of subcutaneous and intra-abdominal fat. Twenty-six obese women (BMI 39 +/- 6) underwent a 15 day very low calorie diet. The study included, both before and after very low calorie diet, computed tomography measurements of total (AT), visceral (VAT) and subcutaneous (SAT) adipose tissue areas, visceral/subcutaneous area ratio (V/S), waist/hip circumference ratio measurements (W/H), and ultrasound measurements of abdominal subcutaneous skin-muscle thickness, intra-abdominal muscle-aorta thickness and intra-abdominal/subcutaneous thickness ratio. Weight reduction was from 101 +/- 17 to 95 +/- 16 kg (P less than 0.001). W/H dropped from 0.83 +/- 0.06 to 0.82 +/- 0.07 (n.s.). VAT dropped from 158 +/- 72 to 134 +/- 61 cm2 (P less than 0.005), SAT from 572 +/- 151 to 566 +/- 164 cm2 (n.s.) and V/S from 0.29 +/- 0.15 to 0.25 +/- 0.11 (P less than 0.01). Abdominal subcutaneous fat thickness decreased from 36 +/- 8 to 35 +/- 10 mm (n.s.), intra-abdominal thickness from 39 +/- 25 to 20 +/- 20 mm (P less than 0.001) and intra-abdominal/subcutaneous from 1.1 +/- 0.7 to 0.8 +/- 0.6 (P less than 0.005). VAT measurement accurately identified small intra-abdominal fat variations. W/H could not evaluate visceral fat loss, because of simultaneous decreases in waist and hip circumferences. Ultrasound was able to measure small reductions in intra-abdominal fat.

Abdomen↗
PubMed1991

A simple test for predisposition to LDL oxidation based on the fluorescence development during copper-catalyzed oxidative modification.

When human low density lipoprotein (LDL) obtained from 10 volunteers was incubated in air at 37 degrees C in the presence of various concentrations of copper, an increase in fluorescence was observed with emission maximum at 430 nm when excitation was performed at 360 nm. The fluorescence increase was inhibited by ethylenediamine tetraacetic acid and by 4-methyl-2,6-di-tert-butylphenol. The fluorescence was found to be tightly bound to the protein moiety. Furthermore, Cu2+ modification of LDL was associated with a decrease in the reactive amino groups of apolipoprotein B and in the uptake of the lipoprotein by rabbit fibroblasts. Under our conditions, the fluorescence increase showed two consecutive periods; an inhibition period during which the fluorescence increased only weakly, and a propagation period with a rapid increase in fluorescence that was linear for at least 5 h. Both periods were influenced by copper concentration. The study also shows that the extent of fluorescence generated upon LDL oxidation varied greatly in the volunteers. Thus, while the results demonstrate that the fluorescence increase may likely monitor the extent of the apoB derivatization, the calculation of the fluorescence development rate of the propagation period together with the duration of the inhibition period may constitute a quantitative measurement of the susceptibility of apoB to be derivatized.

Analysis of Variance↗
PubMed1990

The contribution of sonography to the measurement of intra-abdominal fat.

A study was conducted on a group of 50 obese females with a mean body mass index of 39 +/- 16, aged 19 years, in order to determine if sonography could be adopted as a direct means for measuring intra-abdominal fat deposits. Adipose tissue evaluation was performed by computed tomography (CT) and ultrasonography (using 3.5-MHz and 5-MHz probes) at the L4 level. CT intra-abdominal fat area (VAT) and ultrasonography visceral thickness from abdominal muscle to aorta were the values mainly considered. Ultrasonographic intra-abdominal thickness correlated well with VAT (r = 0.669, p less than 0.001), supporting the hypothesis that ultrasonography could be useful in the direct evaluation of intra-abdominal fat deposits.

Abdomen↗
PubMed1990

Resting metabolic rate, body composition and thyroid hormones. Short term effects of very low calorie diet.

27 obese women (relative body weight 191 +/- 27%), aged 35 +/- 11, underwent a 15 day very low calorie diet (VLCD: 1337 kJ/day). Mean body weight loss was 6 +/- 1.5 kg. Resting metabolic rate (RMR), measured by indirect calorimetry, showed a significant decrease both in absolute values (from 1793 +/- 225 to 1569 +/- 231 kcal/day; P less than 0.001), and in keal/kg body weight/day (from 17 +/- 2, to 16 +/- 2, P less than 0.001). Serum triiodothyronine (T3) significantly decreased from 1.1 +/- 0.2 to 1 +/- 0.2 microgram/1 (P less than 0.001). Before VLCD the differences between measured RMR and theoretical RMR (RMR-T) were not significant. After VLCD RMR values were significantly (P less than 0.001) lower than RMR-T. It was concluded that fat-free mass loss, combined with periferic thyroxin (T4) reduced monodeiodination in its more active form mainly due to low calorie intake T3 could be responsible for the important reduction observed in the resting metabolic rate.

Adult↗
PubMed1990

Modifications of abdominal fat and hepatic insulin clearance during severe caloric restriction.

Using computed tomography on 19 obese female subjects, we determined abdominal adipose tissue, both subcutaneous and visceral adipose tissue, before and after 2 weeks of a very low caloric diet (VLCD). The following parameters were also determined before and after 15-20 days of VLCD: plasma glucose and insulin levels, oral glucose tolerance test, basal pancreatic insulin secretion estimated by fasting C peptide (Cp), and fasting insulin hepatic clearance calculated by Cp/insulin molar ratio. After VLCD the body weight and body mass index significantly declined (p less than 0.01); whereas abdominal adipose tissue and visceral abdominal tissue (VAT) significantly decreased (p less than 0.01), modifications of subcutaneous abdominal tissue (SAT) were not significant. Fasting insulin levels and plasma glucose response to oral glucose load significantly decreased (p less than 0.05). Insulin response remained unchanged. Cp immunoreactive insulin (IRI) significantly increased (p less than 0.01). A significant positive correlation was found between delta VAT and delta Cp/IRI before and after VLCD (p less than 0.01). Our data seem to suggest that the weight loss induced by VLCD fundamentally involves a decrease in VAT. The reduction in visceral fat could be associated with an increase in hepatic insulin clearance.

Abdomen↗
PubMed1990

Blood pressure, metabolic variables and adipose tissue distribution in pre- and post-menopausal women.

The study was performed on 289 female patients (aged 20-60) of a family doctor in Castel D'Azzano, a small town near Verona. The following variables were considered: body mass index (BMI), tricepital, subscapular, hypomesogastric, epimesogastric, supra-iliacal and epitrochanteric skinfolds, waist, umbilical and bitrochanteric circumferences, cholesterol, triglycerides, HDL-cholesterol, glycemia, uricemia and blood pressure. A significant worsening with age was observed in the mean values of the variables. This worsening was particularly evident in women over 50. The population was subdivided according to presence or absence of menopause; the two groups were then matched for age. None of the variables showed significant differences. Our results did not confirm any of the many effects that menopause is supposed to have regarding metabolic and blood pressure alterations.

Adipose Tissue↗
PubMed1988

Long-term effect of a low-fat, high-carbohydrate diet on plasma lipids of patients affected by familial endogenous hypertriglyceridemia.

We evaluated the effect of a low-fat, high carbohydrate (LFHC) diet on plasma lipids in 10 patients affected by familial endogenous hypertriglyceridemia. All the patients studied underwent a base-line period of 4 wk, a 12-wk intervention period, and an 8-wk switch-back period. During the control periods patients consumed approximately 45% of energy as fat and approximately 40% as carbohydrate. During the intervention period they consumed an isocaloric diet containing approximately 25% of energy as fat and approximately 60% as carbohydrate. Total plasma triglyceride and cholesterol levels decreased significantly after 45 and 90 d of treatment (p less than 0.01). The reduction of plasma cholesterol was associated mostly with the decrease in VLDL cholesterol (p less than 0.01) while LDL cholesterol increased at days 45 and 90 of the LFHC diet (p less than 0.01). Finally, we observed a significant increase in HDL cholesterol both at days 45 and 90 of the LFHC diet (p less than 0.01). The LFHC diet we used may be an useful tool in the management of hypertriglyceridemia.

Cholesterol↗
PubMed1988

Short- and long-term effects of hypocaloric diets containing proteins of different sources on plasma lipids and apoproteins of obese subjects.

The influence of caloric restriction on lipid profile is controversial. This study was designed to evaluate the influence of dietary proteins from different sources on lipoprotein levels in obese subjects during a period of very low-caloric diet followed by 60 days of hypocaloric diet. The subjects were 24 obese patients aged 25-42 of at least 50% above ideal weight. The patients were separated into two groups and received for 15 days 375 kcal/day on the assumption that commercial textured preparations contained the same amount of proteins, respectively, as casein (group A) or soy protein (group B). Then the very low-caloric diet of the two groups was integrated with 425 kcal/day for 60 days. Body weight reduction was equivalent in the two groups. Total plasma cholesterol decreased significantly in both groups after the two periods of diet, but the percent variations were always significantly higher in the group B than in A. Total plasma triglycerides reduced significantly only in the group B. Very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) cholesterol behaved as total cholesterol in the two groups. High-density lipoprotein (HDL) cholesterol diminished significantly only after the 15 days of very low-caloric diet in group B, while it decreased throughout the diet in group A. The decrease of HDL cholesterol was mainly due to the HDL2 subfraction. The results of our study show that the substitution of soy protein for casein can be of benefit in those patients who need a long-term hypocaloric diet.

Adult↗
PubMed1988

High-density lipoprotein composition in obesity: interrelationships with plasma insulin levels and body weight.

Hyperinsulinism may play a role in the development of atherosclerosis. In this study we analyzed the interrelationships between plasma glucose, insulin, body weight and high-density lipoproteins (HDL) in a group of obese women and faced the question of what is the effect of obesity on insulin, glucose and HDL relationships. HDL cholesterol was significantly lower, while HDL triglycerides resulted significantly higher in the obese women than in the controls. The two groups did not show any difference in the serum concentration of HDL apoprotein A-I and apoprotein A-II. There was an inverse correlation between fasting plasma glucose and summated means of glucose and insulin levels after an oral glucose tolerance test and HDL cholesterol in the two groups; on the contrary a positive relationship between the same parameters and HDL triglyceride occurred. HDL cholesterol was inversely related also to the weight index, while HDL triglyceride concentration was directly correlated with this parameter in the two groups. Partial correlation analysis demonstrates that, when exposed to similar plasma insulin and glucose levels, HDL cholesterol and triglyceride concentrations were no longer correlated with the weight index, and therefore that the significant correlations between these variables are likely to be due to the significant correlations of each of them with plasma glucose and insulin levels. Further studies clarifying the role of glucose and insulin in determining HDL composition would appear important.

Adult↗
PubMed1987

Metformin enhances insulin binding to "in vitro" down regulated human fat cells.

Insulin binding to human adipose tissue from surgical patients was determined after three different preincubation conditions: a) 24 hrs in the presence or absence of 80 ng/ml insulin; b) 24 hrs in the presence of 80 ng/ml insulin or insulin plus 4 micrograms/ml metformin; c) 48 hrs pre-incubation as in b). We found that insulin down regulated its own receptor after 24 hours pre-incubation; when metformin was present in the pre-incubation medium together with insulin, insulin binding to adipose tissue was significantly higher than in tissue exposed to insulin alone after 48 hrs pre-incubation; a similar effect of metformin was already seen after 24 hrs, but was not statistically significant. We suggest that metformin can correct down regulation of the insulin receptor. This finding could explain discrepant results among studies dealing with the influence of metformin on insulin binding. Moreover, these results could be useful in understanding the mechanism of action of metformin in insulin-resistant states, e.g. type II diabetes.

Adipose Tissue↗
PubMed1986

Effect of insulin on lipolysis in adipose tissue of rats of different ages.

Several authors have not been able to find any antilipolytic effect of insulin in adipose tissue "in vitro". We investigated the possible role of cell size and/or age of donors on this phenomenon. The lipolytic rates (glycerol release per cell) were lower in the small cells of the 4-6 weeks old rats than in the larger cells of the 25-30 weeks old animals; however, the difference disappeared when the data were expressed per unit of cell surface area. Insulin (0.5-50 ng/ml) failed to inhibit both maximally and submaximally noradrenaline stimulated lipolysis in the adipocytes of the young rats, but its antilipolytic action was fully restored by using glucose-free medium. Therefore, at our experimental conditions, a glucose dependent factor, possibly involving the preferential hydrolysis of newly synthetized triglycerides, seems to blunt or to mask the insulin induced inhibition of glycerol release. Relatively higher rates of glucose metabolism and a lower lipolysis in small fat cells might explain the difference in the action of insulin on glycerol release in the adipose tissue of young rats as compared to the older ones.

Adipose Tissue↗
PubMed1986

Isolation and ultrastructural features of brown adipocytes in culture.

Interscapular brown adipose tissue was removed from young rats, the cells isolated using collagenase, pelleted by centrifugation and cultured. Ultrastructural observations were made on these cells immediately after isolation and on Days 1, 2, 4, 10 and 14 of culture. The isolated cells show the typical submicroscopic features of cells in intact brown adipose tissue, i.e. a multivacuolar lipid depot and numerous typical mitochondria with dense cristae. However, as early as Day 1 of culture, the cells show degeneration of the typical mitochondria which are probably then extruded from the cells. Atypical mitochondria now begin to appear and become dominant on Day 4 of culture. By contrast, the typical multivacuolar shape of the lipid droplet does not change. Not even after prolonged periods of culture (2-4 weeks) is there any evidence of coalescence of the multivacuolar lipid depot. These findings are consistent with the possibility that the typical mitochondria of brown adipocytes depend on in vivo conditions, perhaps adrenergic innervation, while the multivacuolar characteristic of the lipid depot does not, and may be an intrinsic feature of the brown adipose cell.

Adipose Tissue, Brown↗
PubMed1985

Human brown adipose cells in culture.

Brown adipose tissue (BAT), obtained from the axillary and perirenal regions of newborns 24-48 h after death, was digested with collagenase and the free cells were cultured. Only the cultures of cells from tissue obtained later than 24 h post mortem were successful. These cells grew slowly to reach confluence. Their typical mitochondria gradually disappeared, being replaced by untypical mitochondria. After confluence, the cells accumulated large amounts of lipid in non-coalescent multivacuolar depots. This model can be useful for the study of the metabolic and morphological features of human brown fat cells.

Adipose Tissue, Brown↗
PubMed1985

Effects of severe caloric restriction on the degree of sialylation of apoprotein C-III in obese women.

Alterations in the relative proportions of very low density lipoprotein (VLDL) apoprotein C-III (apoC-III) isoforms have been previously observed under various dietary and metabolic states. This study was designed to evaluate the effects of a very high caloric restriction on plasma triglycerides and on the relative proportions of VLDL apoprotein C-II (apoC-II) and apoC-III isoforms in obese subjects. VLDL were isolated by preparative ultra-centrifugation from 12 obese women. ApoC-II and apoC-III subspecies were separated by analytical ultrathin-layer isoelectrofocusing. The mean body weight decreased significantly from 96.2 +/- 8.7 to 90.6 +/- 7.6 kg (p less than 0.01). Mean total and VLDL triglycerides did not vary significantly. Apoprotein C-III2 (apoC-III2) as percentage of total apoprotein C increased (p less than 0.01) and apoprotein CIII0 (apoC-III0) decreased (p less than 0.01). Apoprotein C-III1 (apoC-III1) did not vary significantly. An inverse correlation was found between the percentage variation of apoC-III2 and that of apoC-III1 (r = -0.94; p less than 0.01). The variations of apoC-III2 correlated positively (r = 0.83; p less than 0.01), while those of apoC-III1 correlated inversely (r = -0.65, p less than 0.025) with the changes of VLDL triglycerides. The apoC-III1 to apoC-III2 ratio as well as the apoC-III0 to apoC-III2 and apo C-III1 ratios decreased after diet (p from less than 0.01 to less than 0.001). Total apoC-III as well as apoC-III2 and apoC-III1 to apoC-II ratios did not vary.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗