ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.490600.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Steroids have the ability to alter adipose tissue distribution. Controversy exists as to whether these effects of sex hormones (oestrogen, progesterone and testosterone) on human adipose tissue are indirect or direct, as only very few studies have focused on steroid receptor status in human adipose tissue. In the present study, we reinvestigated steroid receptor status in human mature adipose tissue and human preadipocytes. Oestrogen, glucocorticoid and androgen receptors were found in human mature adipocytes from both women and men. The receptors were detected by ligand binding. Furthermore, the existence of the receptors was confirmed by demonstrating that adipocytes contained mRNA encoding the receptors. cDNA was generated using reverse transcriptase (RT) followed by polymerase chain reaction (PCR) amplification using specific primers (RT–PCR) for the specific steroid receptors. Adipocytes did not contain mRNA encoding the progesterone receptor (PR), and no progesterone binding was detectable in human adipocytes. Human preadipocytes contained glucocorticoid receptor (GR) mRNA and androgen receptor (AR) mRNA, whereas we were unable to detect oestrogen receptor (ER) mRNA and progesterone mRNA in human preadipocytes. In conclusion, oestrogen glucocorticoid and androgen receptors are present in mature adipocytes from subjects of both sexes, whereas adipocytes do not contain progesterone receptors. In preadipocytes, only glucocorticoid receptors and androgen receptors are present, whereas oestrogen receptors and progesterone receptors are not presen

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.380603.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The high risk of vaso‐occlusive events in children younger than 4 years with cyanotic congenital heart disease and polycythaemia has been attributed to increased thromboxane (Tx) A2formation. In older children with cyanotic congenital heart disease, however, the risk of vaso‐occlusive events is much lower. We therefore hypothesized that the formation of TxA2and prostacyclin is not disturbed in this age group. We measured urinary excretion of stable index metabolites ofin vivoTxA2and prostacyclin formation by gas chromatography–mass spectrometry in nine children (age 5.9–14.4, median 8.7 years) with cyanotic congenital heart disease, and in nine healthy, age‐matched control subjects. The patients excreted less 2,3‐dinor‐TxB2(systemic TxA2formation,P=0.03), 2,3‐dinor‐6‐keto‐PGF1α(systemic prostacyclin formation,P=0.03) and TxB2(renal TxA2formation,P=0.01) than the control subjects. We conclude that in children older than 5 years with cyanotic congenital heart disease, endogenous synthesis of TxA2and prostacyclin is not stimulated. This result may explain the lower risk of vaso‐occlusive events in this age group as compared with younger children. In addition, our results suggest that chronic hypoxaemia may affect thein vivoformation of TxA2and prostacyclin and the metab

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.370590.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The effect of sequential combined hormone replacement therapy on the susceptibility of low‐density lipoprotein to oxidative modification was investigated in a double‐blind, randomized placebo‐controlled study. Hypercholesterolaemic, postmenopausal women were supplemented with 17β‐oestradiol and norethisterone acetate (n=13 subjects) or placebo capsules (n=15 subjects) for 12 weeks. They were instructed to follow the American Heart Association step one diet. Low‐density lipoprotein, isolated before and after treatment, was subjected to copper‐catalysed lipid peroxidation. There were no significant differences between low‐density lipoprotein from the hormone replacement therapy and placebo groups, as assessed by measuring the lag time for formation of conjugated dienes, the rate of formation and the amount of conjugated dienes formed, the amount of lipid peroxides generated, and the relative electrophoretic mobility at baseline and after treatment. Dietary records showed that the subjects were consuming similar amounts of fat and vitamins. No major differences were found in the fatty acid pattern of low‐density lipoprotein from the two groups. In conclusion, the results indicated that hormone replacement therapy with 17β‐oestradiol sequentially combined with norethisterone acetate in non‐smoking, hypercholesterolaemic, postmenopausal women has no protective effect on the susceptibility of low‐density lipoprotein to copper‐catal

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.390593.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

ThePhyllanthus amarusplant shows potential for treating hepatitis B virus. To define the mechanism of action ofP. amarus, we used HepG2 2.2.15 cells, which support hepatitis B virus replication.P. amarusinhibited hepatitis B virus polymerase activity, decreased episomal hepatitis B virus DNA content and suppressed virus release into culture medium. To examine transcriptional control mechanisms, we used G26 hepatitis B virus transgenic mice, which produce serum HBsAg but neither HBcAg nor virion particles. WhenP. amaruswas administered to transgenic mice, hepatic HBsAg mRNA levels decreased, indicating transcriptional or post‐transcriptional down‐regulation of the transgene. Increase in hepatitis B virus mRNA expression after stimulation of the glucocorticoid responsive element was also suppressed byP. amarus, suggesting involvement of the hepatitis B virus enhancer in this response. Disruption byP. amarusof hepatitis B virus polymerase activity, mRNA transcription and replication supports its role as an antiviral ag

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.410595.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The effects of diadenosine tetraphosphate (AP4A) diadenosine pentaphosphate (AP5A) and diadenosine hexaphosphate (AP6A) on the cytosolic‐free calcium concentration ([Ca2+]i) were evaluated in cultured rat glomerular mesangial cells (MCs) using the fluorescent dye technique. The addition of 10 μmol L−1AP4A, AP5A or AP6A significantly increased [Ca2+]iin MCs by 57±9 nmol L−1n=17;P<0.001), 76±27 nmol L−1(n=9;P<0.001) or 65±12 nmol L−1(n=18;P<0.01) respectively. In the absence of extracellular calcium, there was no significant change in [Ca2+]iin MCs after administration of diadenosine polyphosphates, indicating that these agents induce transplasma membrane Ca2+influx. AP6A significantly enhanced the angiotensin II‐induced changes in [Ca2+]iin MCs. The AP5A‐induced transplasma membrane Ca2+influx was inhibited by the P2purinoceptor blockers suramin and pyridoxal‐phosphate‐6‐azophenyl‐2′,4′‐disulphonic acid (PPADS), but was not affected by the adenosine A1receptor blocker 8‐cyclopentyl‐1.3‐dipropylzanthine (CPDPX). Adenosine triphosphate (ATP) and adenosine 5′‐O‐(3‐thio)triphosphate (ATP‐γS) increased [Ca2+]iin MCs, whereas α,β‐methylene ATP had no effect on [Ca2+]iin MCs. Measurements of diacylglycerol and phosphatidic acid showed that AP5A and AP6A also stimulated phospholipase C, but had no effect on phospholipase D. The inhibition of phosphatidylcholine‐specific phospholipase C significantly reduced the AP5A‐induced [Ca2+]iincrease. In summary, diadenosine polyphosphates induce Ca2+influx through P2purinoceptors and may be involved in the local regulation of vascular resista

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.400592.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The objective of the present study was to investigate the effects of isolated limb perfusion (ILP) with tumour necrosis factor alpha (TNF‐α) and melphalan in patients with cancer on, first, plasma levels of cytokines, second, systemic monocyte and T‐lymphocyte distribution and, third, the ability of mononuclear cells to produce cytokines upon stimulationin vitro. Six patients undergoing an ILP were entered into the study (group 1). In addition, patients undergoing a major surgical operation (group 2), minor operation (group 3) as well as healthy volunteers (group 4) were included as control groups. Sensitive enzyme‐linked immunosorbent assays (ELISAs) were used to measure TNF‐α and interleukin‐6 (IL‐6) plasma levels at various time points during and after operation. Furthermore, the percentage of monocytes and T lymphocytes was determined in all studied groups using a FACScan. In addition, cytokine production upon stimulation with lipopolysaccharide (LPS) and a combination of anti‐CD3/anti‐CD28 monoclonal antibodies in whole‐blood cultures was investigated. Increased plasma levels of TNF‐α and IL‐6 in patients undergoing ILP was observed, but only IL‐6 appeared to be increased in patients treated with a major operation. No significant fluctuations were found in the other groups studied. Concerning the number of monocytes, a significant decrease was observed only in patients treated with ILP. Furthermore, a decreased production of TNF‐α, IL‐6 and IL‐8 upon various types of stimulationin vitrowas found in those patients, but also after a major operation. In conclusion, the results of the present study show increased plasma levels of cytokines in patients treated with ILP and major operation. Furthermore, a decrease in numbers of monocytes in the circulation and the ability of mononuclear cells to produce cytokinesin vitromay be induced by administration of TNF‐α in ILP. Although similar results were found in patients treated with major operation, the underlying mechanisms of thi

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.480599.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

To gain insight into the nature of the immune response with respect to accumulation and composition of the T‐cell receptor (TCR) repertoire in synovial tissue in rheumatoid arthritis (RA), we have determined the nucleotide sequence of TCRBV regions transcribed by T lymphocytes derived from synovial tissue. Synovial tissue was obtained by needle biopsies from three different sites of the same joint in two early RA patients. We found that the TCRBV region repertoire among synovial tissue‐infiltrating mononuclear cells was heterogeneous when the different biopsies taken from each patient were compared. However, DNA sequence analysis of TCRBV rearrangements of synovial T lymphocytes showed conserved amino acid usage profiles in the CDR3 domains of different TCRBV regions, which exhibited an individual specific character. These CDR3 motifs were not present in paired samples of peripheral blood. The existence of homologous CDR3 amino acid profiles within the TCRBV regions derived from synovial tissue is indicative of an antigen‐driven immune res

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.440597.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Protease activity of 10 differentH. pyloristrains, purified marker proteases and protease‐positive reference bacteria (Klebsiella ozaenae, Serratia marcescens) were tested against bovine haemoglobin, porcine mucin, bovine serum albumin, gelatin and casein as substrates. After incubation in development buffer and subsequent staining with Coomassie blue, protease activity bands were demonstrated as transparent spots after polyacrylamide gel electrophoresis (PAGE) on gels with incorporated substrate. Presence of protease activity was investigated in a wide pH range (pH 2.0–9.0). Although marker proteases (0.15–0.2μg per slot) as well as protease‐positive bacteria (2–30μg per slot) clearly showed proteolytic activity in gels containing 0.1–0.2% proteinmL−1, no proteolytic activity was demonstrated in any of theH. pyloristrains tested. This finding indicates thatH. pyloridoes not possess significant protease activity, as this would have been detected by this

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.470598.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

The aims of the study were to characterize the denaturation of urinary free and conjugated pyridinoline (Pyr) and deoxypyridinoline (Dpyr) on exposure to ultraviolet (UV) and natural light at different pH levels and to study the effects of X‐ and γ‐irradiation on Pyr and Dpyr in urine and in the mineralized and non‐mineralized compartments of human bone. Urine samples from six normal subjects, adjusted to pH 3.0, 7.0 and 9.0, were exposed to UV light for up to 3 days. Urine collections (2 mL and 24 h) from three subjects, pH adjusted to 1.0, 2.0, 3.0, 4.0 and 5.0, were exposed to natural light for up to 1 day. Urine samples and bone slices from seven human cadaveric femurs were irradiated with increasing doses of X‐rays (0–100 Gy) and high‐dose γ‐radiation (28kGy). Mineralized and non‐mineralized bone were separated using a modification of a published method employing heat denaturation followed by trypsin hydrolysis and analysed for Pyr, Dpyr and hydroxyproline (Hypro). The rate of UV photolysis of urinary Pyr and Dpyr increased with pH and was faster in the free fraction (after 3 days’ exposure: free Pyr and Dpyr at pH 7.0 vs. 9.0,P<0.05, conjugated pH 3.0 vs. 9.0,P<0.05). Exposure to natural light for 3 h did not significantly decrease urinary Pyr and Dpyr in either sample collections, but levels were reduced in the 2‐mL aliquots after exposure for 1 day (P<0.05). X‐irradiation of urine and bone did not affect Pyr and Dpyr. Pyr content was similar in both bone compartments (Pyr/Hypro=0.12±0.004), but Dpyr was higher in the non‐mineralized compartment (Dpyr/Hypro=0.047±0.002 vs. 0.038±0.002,P<0.001). UV light and γ‐irradiation result in denaturation of pyridinium cross‐links in urine. These cross‐links are present in both the mineralized and non‐mineralized bone compartments but are not affected by the doses of γ

ISSN:0014-2972    

DOI:10.1046/j.1365-2362.1996.460602.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY