To clarify the mechanism of leptin resistance during pregnancy, we measured plasma leptin concentrations, free to total leptin ratio (percent free leptin) and soluble leptin receptor concentrations in pregnant women, and compared the results with those in non-pregnant women. We collected plasma samples from 23 non-pregnant and 31 pregnant women in the third trimester. Plasma samples from 5 pregnant women were collected longitudinally in each trimester. Plasma leptin concentrations in pregnant women in the second trimester (17.4 +/- 3.2 ng/ml) were higher than those in the first trimester of pregnancy (11.0 +/- 2.8 ng/ml, n = 5), as previously reported. However, percent free leptin did not change significantly throughout pregnancy. Percent free leptin correlated with total leptin concentrations (ng/ml) in non-pregnant women (r = 0.727, P < 0.0001), but not in women in the third trimester of pregnancy (r = 0.006). Constant percent free leptin during pregnancy despite increased leptin concentrations indicates increased leptin binding capacity in pregnant women, that might partly contribute to the establishment of leptin resistance. On the other hand, soluble leptin receptor concentrations showed significant negative correlation with BMI and plasma leptin concentrations in pregnant women (r = -0.470, P < 0.01 and r = -0.493, P < 0.01, respectively) but not in non-pregnant women. These data suggest the possibility that soluble leptin receptor is a minor component of leptin binding capacity in the plasma of pregnant women. 相似文献
Objective: To investigate the potential beneficial effects of guideline-based pharmacological therapy on pulmonary function and quality of life (QOL) in Japanese chronic obstructive pulmonary disease (COPD) patients without prior treatment.
Research design and methods: Multicenter survey, open-label study of 49 Japanese COPD patients aged ≥ 40 years; outpatients with >10 pack years of smoking history; ratio of forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 70%; predicted FEV1 < 80%; treated with bronchodilators and/or inhaled corticosteroids as maintenance therapy until week 48.
Main outcome measures: The primary endpoint was change in pulmonary function (trough FEV1, trough FVC); secondary endpoints were QOL and physical activity at 48 weeks after initiation of therapy.
Results: Airway reversibility was confirmed in untreated patients. Significant changes over time were not observed for FEV1 and FVC, indicating lung function at initiation of treatment was maintained during the observation period. COPD assessment test scores showed statistical and clinical improvements. Cough, sputum, breathlessness, and shortness of breath were significantly improved.
Conclusions: Lung function and QOL of untreated Japanese COPD patients improved and improvements were maintained by performing a therapeutic intervention that conformed to published guidelines. 相似文献
It has been shown that cigarette smoking increases blood pressure (BP) and heart rate (HR), and decreases muscle sympathetic nerve activity (MSNA) in healthy young smokers. The decrease in MSNA might be secondary to baroreflex responses to the pressor effect. We tested the hypothesis that cigarette smoking increases MSNA in smokers with impaired baroreflex function. The effects of cigarette smoking on BP, HR, forearm blood flow (FBF), forearm vascular resistance (FVR), and MSNA were examined in 14 patients with stable effort angina (59+/-3 years, group CAD) and 10 healthy smokers (23+/-1 years, group C). In group CAD, the arterial baroreflex sensitivity (BRS) was significantly lower than in group C (4.7+/-0.8 versus 15.1+/-2.2 msec/mmHg, P<0.01). In both groups, cigarette smoking increased the plasma concentration of nicotine, systolic and diastolic BP, HR, and FVR significantly (P<0.01), but decreased FBF significantly (P<0.01). After smoking, MSNA was decreased significantly in group C (from 35.2+/-3.5 to 23.5+/-3.2 bursts/100 beats, P<0.01), but increased significantly in group CAD (from 48.8+/-5.4 to 57.3+/-5.5 bursts/100 beats, P<0.01). There was significant correlation between BRS and changes in MSNA (r= -0.62, P<0.01). Cigarette smoking increased MSNA in smokers with impaired baroreflex function. This demonstrates that cigarette smoking stimulates sympathetic nerve activity by both a direct peripheral effect and a centrally mediated effect. 相似文献
OBJECTIVES: The relation between the occurrence of pacing-induced mechanical alternans and prognosis in patients with mild-to-moderate idiopathic dilated cardiomyopathy (IDCM) in sinus rhythm was investigated prospectively. The myocardial expression of genes for Ca2+-handling proteins in such patients was also examined. BACKGROUND: Mechanical alternans occurs in some patients with severe heart failure, but the relation between the occurrence of mechanical alternans and prognosis in patients with IDCM has remained unknown. METHODS: Left ventricular (LV) pressure was measured during atrial pacing, and LV endomyocardial biopsy specimens were collected in 36 IDCM patients and 8 controls. Idiopathic dilated cardiomyopathy patients were divided into two groups consisting of 22 individuals who did not develop mechanical alternans at heart rates up to 140 beats/min (group A) and of 14 individuals who did (group B). The patients were followed up for a mean of 3.7 years. RESULTS: There was no significant difference in LV ejection fraction or the plasma concentration of brain natriuretic peptide between groups A and B. The myocardial abundance of ryanodine receptor 2 messenger ribonucleic acid (mRNA) was significantly lower in groups A and B than in controls, whereas that of sarcoplasmic reticulum Ca2+-ATPase mRNA was significantly lower in group B than in group A or controls. Stepwise multivariate analysis identified pacing-induced mechanical alternans as the strongest predictor of cardiac events. Event-free survival in group A was significantly greater than that in group B. CONCLUSIONS: The occurrence of pacing-induced mechanical alternans is a potentially useful indicator of poor prognosis in patients with mild-to-moderate IDCM in sinus rhythm. 相似文献
Hyperglycemia increases oxidative stress in various tissues and leads to diabetic cardiovascular complication. Dyslipidemia,
such as an increase in oxidized low-density lipoprotein (LDL), is well recognized in diabetic patients with hyperglycemia.
However, the mechanism by which hyperglycemia causes the increased LDL oxidation remains unclear. Albumin is the most abundant
protein in the circulation, and can function as an antioxidant. Therefore, we examined whether glycoxidative modification
inhibits the antioxidant activity of albumin to LDL oxidation and clarified the mechanism by which this modification may suppress
its antioxidant activity. Human serum albumin (HSA) was incubated in phosphate-buffered saline with and without glucose at
37°C for up to 8 weeks under aerobic conditions (referred to as glycoxidation (goHSA) and oxidation (oHSA), respectively).
Metal chelator-treated, nonoxidative HSA (chHSA) and freshly prepared HSA (fHSA) were used as controls. Nε-(carboxymethyl)lysine (CML), a glycoxidative product, was determined by enzyme-linked immunosorbent assay. Oxidation was
estimated by measuring the thiols of the HSA molecule. Copper-mediated oxidation of LDL was conducted in the presence or absence
of modified HSAs at 37°C for 6 days. Malondialdehyde and negative charge of LDL were measured. To clarify the mechanism of
reduced antioxidant activity of HSA, we examined firstly the binding activity of modified HSAs to copper, and secondly the
effects of free radical scavengers on the formation of malondialdehyde. CML was formed in goHSA in a time- and concentration-dependent
manner. Both goHSA and oHSA significantly decreased the contents of free thiol groups compared to ch- and fHSAs. The antioxidant
activity of goHSA to LDL oxidation was the lowest among various modified HSAs. The oHSA showed a moderate decrease in antioxidant
activity. The binding activity of go- and oHSAs to copper was lower than that of ch- and fHSAs. The formation of MDA from
LDL oxidation in the presence of goHSA was completely inhibited by Tiron (1,2-dihydroxy-3,5-benzenedisulfonic acid) and superoxide
dismutase. In contrast, catalase and mannitol had no effect. Our results indicate that in vitro glycoxidation of HSA induced
a marked loss of antioxidant activity of this molecule to copper-mediated oxidation of LDL, which may be caused by the generation
of superoxide.
Received: December 17, 2001 / Accepted: June 28, 2002
Acknowledgments The authors thank Drs. Ryoji Nagai and Seikoh Horiuchi (Department of Biochemistry, Kumamoto University School of Medicine,
Kumamoto, Japan) and Drs. Hiroyuki Itabe and Tatsuya Takano (Department of Microbiology and Molecular Pathology, Faculty of
Pharmaceutical Sciences, Teikyo University, Sagamiko, Kanagawa, Japan) for kindly supplying antibodies. We also thank Associate
Professor Takeo Yamaguchi (Department of Chemistry, Faculty of Science, Fukuoka University) for the ESR experiment and Miss
Satoko Nagano for her excellent technical assistance. This work was supported by a Grant-in-Aid from the Ministry of Education,
Science, Sports and Culture of Japan (No. 14570171) and in part by funds from the Central Research Institute of Fukuoka University
(No. 016004).
Correspondence to N. Sakata 相似文献
We describe a 59-year-old woman with sick sinus syndrome (SSS) and arrhythmogenic right ventricular cardiomyopathy (ARVC). Diagnosis of SSS was made because she had frequent episodes of sinus arrest with prolonged ventricular asystole. Cardiac images showed a dilated right atrium (RA) and a right ventricle (RV). Electroanatomical mapping of the RA showed extensive scarring with no recordable electrical potentials. Although she had frequent premature ventricular contractions, neither spontaneous ventricular tachycardia (VT) nor induced VT was observed. Microscopic examination of the RV indicated fibrofatty myocardium. Atrial arrhythmias associated with SSS may be the cause of symptoms in some cases of ARVC. 相似文献
International Journal of Clinical Pharmacy - Background Renal anaemia worsens because of the uraemic status immediately before the initiation of haemodialysis. The haemoglobin level in patients... 相似文献