Search Results - (Author, Cooperation:H. Hauner)

2011-09-29

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Adipocytes/chemistry/metabolism ; Adipose Tissue/cytology/*metabolism ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Carbon Radioisotopes/analysis ; Cell Aging ; Cell Size ; Child ; Child, Preschool ; Cohort Studies ; DNA/chemistry ; Dyslipidemias/metabolism/pathology ; *Health ; Humans ; Hyperlipidemia, Familial Combined/genetics/metabolism/pathology ; *Lipid Metabolism ; Lipolysis ; Metabolic Diseases/*metabolism ; Middle Aged ; Nuclear Weapons ; Obesity/metabolism ; Subcutaneous Fat/metabolism ; Time Factors ; Triglycerides/analysis/metabolism ; Young Adult

0014-5793

3T3-Li Preadipocyte ; Adipogenic serum factors ; Genetically obese rodent

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0022-2828

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Electronic Resource

1432-1440

Fat distribution ; Hyperinsulinemia ; Obesity ; Glucose tolerance ; Non-insulin dependent diabetes

Springer Online Journal Archives 1860-2000

Medicine

Summary Relationship between body fat distribution, serum insulin, and glucose tolerance in obese, non-diabetic women. Recent studies suggest that hyperinsulinemia and upper body obesity are predictive factors for the development of non-insulindependent diabetes mellitus. To further characterize the relationship between body fat distribution, serum insulin, and glucose tolerance an oral glucose tolerance test was performed in 48 obese, nondiabetic women. Fasting insulin levels were correlated to both total body fat calculated as body mass index (r=0.58,p〈0.001) and upper body fat distribution expressed as waist-to-hip ratio (WHR,r=0.47,p〈0.01). In the women with upper body fat localization (WHR〉0.90) significantly higher basal and glucose-stimulated insulin concentrations were established than in the women with a lower body type of obesity (WHR〈0.78) (basal insulin 27.4±11.5 vs. 15.4±8.8 mU/l,p〈0.05, insulin area 779±320 vs. 468±237 U,p〈0.05). They also had impaired glucose tolerance (glucose area 925±139 vs. 633±147 U,p〈0.01). Fasting triglyceride concentrations were correlated both with WHR (r=0.63,p〈0.001) and fasting insulin (r=0.33,p〈0.05) but not with BMI (r=−0.02, n.s.). A positive association was found between systolic and diastolic blood pressure and both WHR (r=0.43 andr=0.44 resp.,p〈0.01) and BMI (eachr=0.35,p〈0.05). Interestingly, basal insulin was also associated with blood pressure (r=0.30,p〈0.1, andr=0.40,p〈0.01 resp.). These results suggest a close relationship between upper body obesity, hyperinsulinemia, and impaired glucose tolerance. Women with an upper body tpye of obesity also show tendencies to hypertriglyceridemia and hypertension. Obese women with upper body obesity represent a subgroup of the obesity population with an increased risk to develop type-II diabetes.

Electronic Resource

1432-1440

Adipose tissue ; Differentiation ; Obesity ; Preadipocytes

Springer Online Journal Archives 1860-2000

Medicine

Summary Obesity is regarded as a heterogeneous syndrome, which may appear in different forms. Various causes have been found to contribute to its pathogenesis. During recent years investigations of adipose tissue cellularity and its dynamic changes have gained growing interest. An important progress was the discovery of adipose tissue precursor cells. These cells have not yet been precisely identified by morphological and biochemical methods in intact tissue. However, due to methodological developments such precursor cells can be cultured both as primary cultures and as established cell lines. These culture systems have proven to be valuable models for the study of the processes involved in the formation of new fat cells.

Electronic Resource

1432-1440

Adipose tissue ; Differentiation ; Obesity ; Preadipocytes

Springer Online Journal Archives 1860-2000

Medicine

Summary Cell culture systems have proven to be valuable models for the study of the processes involved in the formation of new fat cells. Two separate steps may be distinguished in adipocyte development. First, the determination of a mesenchymal stem cell into a preadipocyte, second, its conversion into a mature fat cell. In cloned cell lines adipose conversion depends on at least one postconfluent mitosis possibly induced by insulin-like growth factors or by as yet unknown mitogens. In addition growth hormone, glucocorticoids, and insulin are needed for conversion to take place. The adipose conversion of preadipocytes originating from the stromal vascular fraction of adipose tissue does not depend on postconfluent mitoses and needs only insulin and glucocorticoid hormones in physiological concentrations. However, the ability to undergo adipose conversion is not stable in these cells, but gets lost after repeated subcultures or seeding at low densities. In addition to stimulating hormones an increasing number of factors inhibiting the conversion process have also been detected, the physiological function of which remains unclear at the moment.

Electronic Resource

1432-1440

Diabetic cardiopathy ; Radionuclide Ventriculography

Springer Online Journal Archives 1860-2000

Medicine

Summary Left ventricular function was assessed by means of radionuclide ventriculography in 42 patients with long-standing (13±5 yrs) insulin-dependent diabetes mellitus and in eleven healthy age matched control subjects. Only diabetics were included in the study without diabetes related cardiac risk factors such as hypertension and CAD in order to evaluate diabetes specific changes of cardiac function. No differences were seen between diabetics and controls concerning heart rate and functional parameters of left ventricle in systole and diastole. The rapid filling period was not prolonged. According to our radionuclide data there is no evidence of diabetes related impairment of ventricular function in young patients with long-standing type-1-diabetes mellitus.

Electronic Resource

1432-1440

Coronary artery disease ; Sex hormones ; Obesity ; Body fat distribution ; Angiography

Springer Online Journal Archives 1860-2000

Medicine

Summary The relationship between circulating sex hormone levels and the occurrence of coronary artery disease (CAD) was studied in a group of 274 men undergoing coronary angiography. Hormone levels in men with CAD (n=200) were compared to those in men found to be free of coronary lesions (n=74). No significant differences were found for serum concentrations of estradiol, total testosterone, sex-hormone-binding globulin, free androgen index, dehydroepiandrosterone sulfate, or cortisol between the two groups. Serum androgens were negatively correlated to age in both groups, whereas estradiol was weakly associated with total cholesterol in the group of men without CAD. No consistent associations were detected between sex hormone levels and the degree of obesity or the distribution of body fat, the latter being assessed by the ratio of waist-to-hip circumferences. The results of this study do not support a significant role of sex steroid hormones in coronary artery disease in men.

Electronic Resource

1433-8580

Vasoactive intestinal polypeptide ; Adipose tissue ; Insulin action ; Lipolysis

Springer Online Journal Archives 1860-2000

Medicine

Summary The biologic actions of vasoactive intestinal polypeptide (VIP) on insulin binding, glucose uptake and utilization, and on lipolysis were studied. At concentrations between 10−10 and 10−7 mol/l VIP influenced neither glucose uptake nor glucose incorporation into lipids under basal and insulin-stimulated conditions. This effect was independent of the presence of adenosine deaminase in the incubation medium. At 10−8 mol/l VIP increased insulin binding affinity slightly but not significantly, shifting the ID-50 from 12.4 ng/ml to 10.3 ng/ml, without any change in receptor number. However, VIP showed a marked dose-dependent lipolytic activity with the lowest effective concentration at 10−9 mol/l. At 10−6 mol/l glycerol release increased 7.3-fold as compared to basal lipolysis. In conclusion, VIP did not affect adipose tissue metabolism at physiologic concentrations. In the rare Verner-Morrison syndrome, however, the potent lipolytic activity of VIP may contribute to the metabolic disturbances observed.

Electronic Resource

1432-0428

Viral antibodies ; Beta-cell function ; population study

Springer Online Journal Archives 1860-2000

Medicine

Summary Viral antibodies were tested in a cohort of 44 isletcell antibody-positive individuals age 7–19 years, and 44 of their islet cell antibody-negative age and sex-matched classmates selected from a population study of 4208 pupils who had been screened for islet cell antibodies. Anti-coxsackie B1-5 IgM responses were detected in 14 of 44 (32%) of the islet cell antibody-positive subjects and in 7 of 44 (16%) control subjects. This difference did not reach the level of statistical significance. None of the islet cell antibody-positive subjects had specific IgM antibodies to mumps, rubella, or cytomegalovirus. There was also no increase in the prevalence or the mean titres of anti-mumps-IgG or IgA and anti-cytomegalovirus-IgG in islet cell antibody-positive subjects compared to control subjects. These results do not suggest any association between islet cell antibodies, and possibly insulitis, with recent mumps, rubella or cytomegalo virus infection. Further studies are required to clarify the relationship between islet cell antibodies and coxsackie B virus infections.

Electronic Resource

1432-0428

Key words Cachexia ; glucose transport ; human adipocytes ; insulin resistance ; lipolysis ; tumour necrosis factor alpha.

Springer Online Journal Archives 1860-2000

Medicine

Summary Tumour necrosis factor alpha (TNFα) has been found to cause a delipidation of fat cells and a decrease of the adipose tissue mass. In the present study, we tried to elucidate some of the mechanisms responsible for this phenomenon by investigating the action of TNFα on specific pathways which are involved in lipid storage. Cultured stromal cells from human adipose tissue were induced to differentiate into adipose cells by exposure to adipogenic factors and subsequently used for studying the effects of TNFα on fat cell metabolism. Presence of 5 nmol/l TNFα for 24 h resulted in a complete loss of the stimulatory effect of insulin on 2-deoxy-glucose transport. This inhibitory action was paralleled by a decrease of GLUT4 protein and mRNA levels. The amount of cellular GLUT4 protein was reduced by 49 ± 3 % after a 24-h exposure and by 82 ± 18 % after a 72-h exposure to 5 nmol/l TNF a . GLUT4 mRNA was almost undetectable after a 24-h incubation with 5 nmol/l TNFα. In a similar time-dependent manner, TNFα dramatically reduced the lipoprotein lipase mRNA content of the cells. Furthermore, incubation of cultured human fat cells with TNFα resulted in a marked dose-dependent stimulation of lipolysis, assessed by glycerol release, by up to 400 % above controls, which became apparent after a 6-h exposure at the earliest. These data suggest that TNFα induces a catabolic state in human adipose tissue which includes a loss of the stimulatory effect of insulin on glucose transport. These multiple actions of TNFα may contribute to the loss of adipose tissue observed during cachexia in man. [Diabetologia (1995) 38: 764–771]

Electronic Resource

1432-0428

Keywords Plasminogen activator inhibitor-1, troglitazone, human adipocytes, Type II diabetes, obesity.

Springer Online Journal Archives 1860-2000

Medicine

Abstract Aims/hypothesis. Increased plasma plasminogen activator inhibitor-1 (PAI-1) concentrations are characteristic for subjects with insulin resistance and could contribute to the increased cardiovascular risk in this state. In this study, we investigated the effect of troglitazone, a ligand of the nuclear receptor peroxisome proliferator activated receptor-γ, on PAI-1 expression and secretion in human adipocytes.¶Methods. We used two models: in vitro differentiated subcutaneous and omental adipocytes cultured under serum-free conditions and isolated subcutaneous and omental fat cells kept in suspension culture. Plasminogen activator inhibitor-1 protein was measured by ELISA, PAI-1 mRNA by a semiquantitative RT-PCR technique.¶Results. Exposure of in vitro differentiated subcutaneous adipocytes from young normal-weight females to 1 μg/ml troglitazone for 72 h caused a reduction of both PAI-1 secretion (by 29 ± 5 %; p 〈 0.01) and PAI-1 mRNA expression (by 26 ± 3 %; p 〈 0.05). In cultures from severely obese subjects, troglitazone induced a decrease of PAI-1 antigen secretion from newly differentiated omental adipocytes by 49 ± 8 % (p 〈 0.01) and from subcutaneous adipocytes by 30 ± 7 % (p 〈 0.05). Exposure of freshly isolated subcutaneous and omental adipocytes in suspension culture to troglitazone induced a similar reduction of PAI-1 concentration in the culture medium (by 35 ± 11 %, p 〈 0.05. and 33 ± 8 %, p 〈 0.05 compared with control, respectively).¶Conclusion/interpretation. This study provides evidence that troglitazone reduces PAI-1 production in human adipocytes, probably at the transcriptional level. This observation could point to a new beneficial effect of troglitazone, particularly in obese subjects, which could be associated with a reduced cardiovascular risk. [Diabetologia (2000) 43: 377–383]

Electronic Resource

1432-1289

Schlüsselwörter Adipositas ; Adipositas ; Therapie

Springer Online Journal Archives 1860-2000

Medicine

Zusammenfassung Die gesundheitlichen Risiken der Adipositas sind außerordentlich ernstzunehmen, nicht weniger die volkswirtschaftlichen Folgelasten, für die astronomisch hohe Zahlen im 11stelligen DM-Bereich geschätzt werden. Der seit einiger Zeit zur Einschätzung des Körpergewichts verwendete Body Mass Index (BMI; definiert als Körpergewicht in kg, dividiert durch Körpergröße in m2), für manchen Leser vielleicht ein etwas abstrakter Begriff, sei an einem Beispiel verdeutlicht: Das Gewicht eines 180 cm großen Mannes gilt bis 80,7 kg als „normal” (BMI bis 24,9), ab dann bis ca. 96,8 kg (BMI bis 29,9) als „mäßig übergewichtig” und erst darüber als „behandlungsbedürftig übergewichtig”. Dies entspricht den Richtlinien, die die Deutsche Adipositas-Gesellschaft herausgegeben hat. Man wird einräumen, daß es schwerfällt, im ärztlichen Alltag auch die oberen Grenzwerte unreflektiert hinzunehmen. Die vorliegende Übersicht behandelt Voruntersuchungen, Therapieplanung und -ziele sowie die verschiedenen Methoden der Ernährungsbehandlung unter Berücksichtigung psychologisch notwendiger Maßnahmen, besonders zur Änderung des Eßverhaltens und zur Langzeitbetreuung. Darüber hinaus werden medikamentöse und chirurgische Möglichkeiten der Adipositastherapie aufgezeigt.

Electronic Resource