ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.146269.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The distribution of adipose tissue has a major impact on the morbidity and mortality associated with obesity. Furthermore, the distribution of adipose tissue seems to be regulated by sex hormones. Controversy exists over whether the effects of sex hormones (oestrogen and testosterone) on human adipose tissue are an indirect or a direct effect as contradictory results have been obtained when investigating the existence of these receptors in human adipose tissue. In the present study the authors reinvestigated the possible existence of oestrogen receptors (ERs) in human adipose tissue. Human adipocytes from both genders were found to contain specific oestrogen binding sites determined by ligand‐binding techniques. The binding protein had a molecular weight of 65 kD (which is similar to that of the ER found elsewhere) and it was found that adipocytes contained mRNA encoding the ER. Moreover, human preadipocytes had no oestrogen‐binding capacity and did not possess mRNA encoding the ER. Finally, the authors detected regional differences in receptor density. Women had an equal oestrogen‐binding capacity in adipose tissue from the subcutaneous abdominal and the visceral depot, whereas men had twice as high oestrogen‐binding capacity in subcutaneous adipose tissue compared with adipose tissue in the visceral fat depot. These findings indicate that mature human adipocytes possess ERs and thus, might be an oestrogen‐ responsive tissue and that oestrogen may be acting directly in mature adipocytes via its specific receptor. Human preadipocytes, however, seemed not to be an oestrogen‐responsive tissue. Finally, preliminary data suggest that there might be differences in ER densities in differe

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.145278.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Erythrocytes from patients with erythropoietic protoporphyria contain large amounts of protoporphyrin. The photosensitivity experienced by these patients is assumed to be due to a leakage of protoporphyrin from the erythrocytes and transfer to the skin, where protoporphyrin acts as a photosensitizer. The leakage of protoporphyrin from the erythrocytes has been offered as an explanation for the great variety in protoporphyrin content observed among erythrocytes in this disease. Based on density gradient separation of red cells, it has been concluded that all reticulocytes and young erythrocytes contain large amounts of protoporphyrin. From our results, density gradient centrifugation is not suitable for age separation of red cells from patients with erythropoietic protoporphyria. By developing a new method for isolation of reticulocytes and applying flow cytometry to determine protoporphyrin content in individual cells, it was observed that two populations of reticulocytes were present in patients with erythropoietic protoporphyria, one with and the other without protoporphyrin. The half‐life of protoporphyrin in red cells was found to be 12–14 days, in contrast to 1–2 days described previously, suggesting a slower release of protoporphyrin from the red cells than previously antici

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.115274.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Body composition changes with increasing age in men, in that lean body mass decreases whereas fat mass increases. Whether this altered body composition is related to decreasing physical activity or to the known age‐associated decrease in growth hormone secretion is uncertain. To address this question, three groups of healthy men (n = 14 in each group), matched for weight, height and body mass index, were investigated using dual‐energy X‐ray absorptiometry, indirect calorimetry and estimate of daily growth hormone secretion [i.e. plasma insulin‐like growth factor I (IGF‐I) levels]. Group 1 comprised young untrained subjects aged 31.0 ± 2.1 years (mean ± SEM) taking no regular physical exercise; group 2 consisted of old untrained men aged 68.6 ± 1.2 years; and group 3 consisted of healthy old men aged 67.4 ± 1.2 years undergoing regular physical training for more than 10 years with a training distance of at least 30 km per week. Subjects in group 3 had for the past three years taken part in the ‘Grand Prix of Berne’, a 16.5‐km race run at a speed of 4.7 ± 0.6 min km−1(most recent race). Fat mass was more than 4 kg higher in old untrained men (P < 0.01,anova) than in the other groups (young untrained men, 12.0 ± 0.9 kg; old untrained men, 16.1 ± 1.0 kg; old trained men, 11.0 ± 0.8 kg), whereas body fat distribution (i.e. the ratio of upper to lower body fat mass) was similar between the three groups. The lean mass of old untrained men was more than 3.5 kg lower (P < 0.02,anova) than in the other two groups (young untrained men, 56.4 ± 1.0 kg; old untrained men, 52.4 ± 1.0 kg; old trained men, 56.0 ± 1.0 kg), mostly because of a loss of skeletal muscle mass in the arms and legs (young untrained men, 24.0 ± 0.5 kg; old untrained men 20.8 ± 0.5 kg; old trained men, 23.6 ± 0.7 kg;P < 0.01,anova). Resting metabolic rate per kilogram lean mass decreased with increasing age independently of physical activity (r = −0.42,P < 0.005). Fuel metabolism was determined by indirect calorimetry at rest. Protein oxidation was similar in the three groups. Old untrained men had higher (P < 0.001) carbohydrate oxidation (young untrained men, 13.2 ± 1.0 kcal kg−1lean mass; old untrained men, 15.2 ± 1.3 kcal kg−1; old trained men, 7.8 ± 0.8 kcal kg−1), but lower (P < 0.05,anova) fat oxidation (young untrained men, 10.1 ± 1.2 kcal kg−1lean mass; old untrained men, 6.5 ± 1.0 kcal kg−1; old trained men, 13.7 ± 1.0 kcal kg−1) than the other two groups. Mean plasma IGF‐I level in old trained men was higher than in old untrained men (P < 0.05), but was still lower than that observed in young untrained men (P < 0.005) (young untrained men, 236 ± 24 ng mL−1; old untrained men, 119 ± 13 ng mL−1; old trained men, 166 ±14 ng mL−1). In summary, regular phys

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.124281.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Differential and sometimes contradictory effects have been described for tumour necrosis factor α (TNF‐α) and interferon γ (IFN‐γ) on replication of human immunodeficiency virus type 1 (HIV‐1). The authors examined individual and co‐ordinate action of these cytokines on HIV‐1 expression, and on apoptosis of HIV‐1‐infected host cells by determination of reverse transcriptase activity in cell culture supernatant, expression of HIV‐1‐RNA and production of p24 antigen in the promonocytic cell line U937 and its persistently HIV‐1‐infected clone U1. Apoptosis was demonstrated by typical cleavage of cellular DNA at internucleosomal regions in promonocytic and T‐lymphocytic cell lines. TNF‐α alone markedly stimulated HIV‐1 replication in U1 cells at the transcriptional and on the translational level. Exclusive application of IFN‐γ only slightly enhanced HIV‐1 expression, whereas it synergistically potentiated stimulatory effects of TNF‐α. Both cytokines also synergistically induced apoptosis in HIV‐1‐infected host cells. Co‐ordinate action of TNF‐α and IFN‐γ is suggested to represent an important mechanism for disease progression in HIV infection. These findings demonstrate that cytokine effects on viral expression may va

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.116271.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Our investigation aimed at verifying diastolic abnormalities in rheumatoid patients, without clinically evident cardiovascular disease and other confounding complaints, by using pulsed Doppler examination of transmitral blood flow. We selected 40 patients fulfilling revised American Rheumatism Association (ARA) criteria for the diagnosis of rheumatoid arthritis having no symptoms of cardiac disease or clinical findings of other extracardiac diseases. We also studied 40 rheumatoid‐matched healthy volunteers as a control group. An echocardiographic examination was carried out on each subject. Left ventricular structural and functional measurements were obtained. Interventricular septal thickness and left ventricular mass index were significantly higher in rheumatoid patients than in the control group. We also found in rheumatoid patients higher mean values of peak A velocity and A/E ratio. When multiple linear regression analysis was performed on the data of rheumatoid patients we found an independent relationship only between A/E ratio and left ventricular mass. In conclusion, our results confirm diastolic abnormalities in rheumatoid patients and point out that these abnormalities also affect echo‐Doppler parameters of left ventricular filling. Moreover, further analysis of our data may suggest the possibility that structural left ventricle changes could be responsible for left ventricular filling impairm

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.133284.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Serum neurone‐specific enolase (NSE) and computerized tomography (CT) stroke volume were compared in patients admitted within 24 h of an acute stroke. Serum samples were obtained on admission and daily for the next 4 days. Of 163 patients, CT scans revealed 25 with intracerebral haemorrhages, one haemorrhagic infarct and 83 measurable acute infarcts. The serum NSE levels of those with infarcts was significantly higher than in those with haemorrhages at 48 (P = 0.0003) and 72 h (P = 0.04). The maximum serum NSE value tended to occur later in those with large infarcts (P = 0.0035). There was a significant correlation between infarct volume and serum NSE at 48 h (r = 0.27,P = 0.015) and 96 h (r = 0.27,P = 0.015) and with the maximum serum NSE over the 4 days (r = 0.36,P = 0.001). There was no significant correlation between haemorrhage volume and NSE. In conclusion, serum NSE may be a useful marker of infarct volume in studies of therapy in acute stroke. Sampling for NSE should continue, at least in those with large infarcts, for longer than 4 days. Serum NSE cannot be used to distinguish between haemorrhage

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.129282.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Mild hyperhomocysteinaemia is associated with increased risk for vascular disease. We studied homocysteine export from human umbilical vein endothelial cells (HUVECs) by measuring total homocysteine (tHcy) concentrations in the culture medium. Under standard culture conditions tHcy concentrations in the HUVEC culture medium increased by constant amounts after 24, 48 and 72 h [mean = 2.5 (SD ± 0.7) μmol L−1homocysteine every 24 h]. As the cells are the only source of homocysteine increase in the culture medium, we designate this as homocysteine export from HUVEC. Folic acid supplementation to the culture medium lowered the homocysteine export in a dose‐dependent manner. Methyl‐tetrahydrofolate (MeTHF) and folinic acid (a stable precursor of MeTHF) were in this respect about 10 times more effective than folic acid. A 50% reduction in the homocysteine export was seen with 10–30 nmol L−1MeTHF supplementation; reduction to almost zero was seen with 100–300 nmol L−1MeTHF. Additions to the culture medium of the other vitamins involved in the homocysteine metabolism, such as vitamin B12, vitamin B6and flavin adenine dinucleotide, did not show any effect on homocysteine export. Because homocysteine export reflects an imbalance in the homocysteine metabolism, our observations showed a susceptible dependency of this metaboli

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.137273.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

There is epidemiological evidence that chronic inflammatory diseases occur more frequently in female than in male subjects and prevail differently in various ethnic populations. Phospholipase A2(PLA2) (group II) plays a key role in many inflammatory reactions by releasing free arachidonic acid, which is a prerequisite for the production of proinflammatory lipid mediators. We therefore, measured PLA2activity in plasma, serum, leucocytes and lymphocytes in 20 female and 20 male subjects, 10 of each group being of Asian Indian and of Caucasian origin respectively. When PLA2activity was measured in crude plasma and serum no dependency from gender and ethnicity was observed. Following acid extraction and heating, PLA2activity in plasma was higher in Caucasians (27.8 ± 2.2 nmol L−1 mg −1protein 60 min−1) than in Asian Indians (17.9 ± 2.5 nmol L−1 mg−1protein 60 min−1) (P < 0.005) and higher in females (28.5 ± 2.6 nmol L−1 mg−1protein 60 min−1) than in males (17.3 ± 2.0 nmol L−1 mg−1protein 60 min−1) (P < 0.001). Similar differences were observed when only Asian Indian or Caucasian females were compared with their corresponding males. Contrary to plasma, in which the specific activity of PLA2increased following acid extraction and heating, the activity was completely abrogated in serum after extraction and heating. Lymphocytes exhibited lower activities of PLA2than neutrophils in all four groups of subjects investigated. Females had a tendency towards higher PLA2activity in both lymphocytes and neutrophils than males. In conclusion the present investigation revealed an ethnic‐ and sex‐dependent ba

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.136276.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The nephrotic syndrome is frequently associated with hyperlipidaemia and hyperfibrinogenaemia, leading to an increased coronary and thrombotic risk, which may be enhanced by high lipoprotein (a) [Lp(a)] concentrations. We followed the quantitative and qualitative pattern of plasma lipoproteins over 18 months in a patient with nephrotic syndrome suffering from premature coronary artery disease and with elevated level of Lp(a) (470 mg dL−1). Analysis of kinetic parameters after heparin‐induced extracorporeal plasma apheresis revealed a reduced fractional catabolic rate for both low‐density lipoprotein (LDL) and Lp(a). After improvement of the nephrotic syndrome, Lp(a) decreased to 169 mg dL−1and LDL concentrations were normalized. The decrease of Lp(a) was associated with an increase in plasma albumin concentrations. Analysis of apo(a) isoforms in the patient showed the presence of isoform S2 (alleles 10 and 19). Consequently, the authors’ present strategy is to normalize the elevated Lp(a) and fibrinogen levels. For this purpose heparin‐mediated extracorporeal LDL precipitation (HELP) apheresis is a promising regimen, helping to reduce the thrombotic risk and prevent coronary and graft atherosclerosis as well as the progression of glomeruloscler

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.132283.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY