Increased plasma P-selectin and decreased thrombomodulin in pulmonary arterial hypertension were improved by continuous prostacyclin therapy

BACKGROUND

Thrombosis in situ related to endothelial cell injury may contribute to the development of pulmonary hypertension (PH). P-selectin, a leukocyte adhesion receptor present in endothelial cells and platelets, reflects endothelial injury and platelet activation, and thrombomodulin (TM), a receptor for thrombin and a major anticoagulant proteoglycan on the endothelial membrane, reflects the anticoagulant activity of the endothelium.

METHODS AND RESULTS

To assess abnormal coagulation due to endothelial injury in patients with PH, plasma levels of soluble P-selectin and TM were measured in 32 patients with primary PH (PPH), 25 with secondary pulmonary arterial hypertension (sPAH), 31 with pulmonary venous hypertension (PVH), and 17 healthy subjects (Control). These measurements were repeated after continuous infusion of prostacyclin in 15 patients with PPH and 3 with sPAH. P-selectin levels in both the sPAH and PPH groups were significantly higher than those in the Control and PVH groups (P<0.05). Plasma TM level in the PPH group was significantly lower than those in the other groups (P<0.01). After prostacyclin therapy, the lower TM level was increased and the higher P-selectin level was decreased (P<0.05).

CONCLUSIONS

Decreased TM and increased P-selectin in PPH and sPAH may reflect in situ thrombosis due to endothelial injury. Prostacyclin may act not only as a vasodilator but also as an agent that improves endothelial injury and altered hemostasis in pulmonary arterial injury.

Regulation of Na(+)-K(+)-ATPase by cAMP-dependent protein kinase anchored on membrane via its anchoring protein

Na(+)-K(+)- ATPase alpha-subunits in basolateral membrane vesicles (BLMVs) purified from rat parotid glands were (32)P-labeled within 5 s by incubation with [gamma-(32)P]ATP at 37 degrees C in the presence of cAMP, but no labeling occurred without cAMP. Phosphorylation of Na(+)-K(+)-ATPase was associated with a decrease in its activity. This alpha-subunit phosphorylation disappeared when BLMVs were briefly incubated with cAMP and subsequent washing before the incubation with [gamma-(32)P]ATP, indicating that catalytic subunit of protein kinase A (PKA) associated to BLMVs via binding with its RII regulatory subunit anchored on the membrane. In the absence of cAMP, a PKA catalytic subunit readily reassociated with the membrane-bound RII subunit. HT-31 peptide inhibited the Na(+)-K(+)-ATPase phosphorylation by membrane-bound endogenous PKA, indicating an involvement of A-kinase anchoring protein (AKAP). AKAP-150 protein in BLMVs was shown by immunoblotting and an RII overlay assay and was coimmunoprecipitated by anti-RII antibody. These results show that Na(+)-K(+)-ATPase of rat parotid gland acinar cells is regulated in vivo by membrane-anchored PKA via AKAP rather than by free cytosolic PKA.

Cigarette smoking and risk for hearing impairment: a longitudinal study in Japanese male office workers

The association of cigarette smoking with development of hearing impairment (loss of 30 dB at 1000 Hz and 40 dB at 4000 Hz) over a 5-year follow-up was studied in 1554 non-hearing-impaired Japanese male office workers who ranged in age from 30 to 59 years. After controlling for potential predictors of hearing impairment, the relative risk for low-frequency hearing impairment compared with never smokers was 1.12 (95% confidence interval [CI], 0.57 to 2.17) for ever-smokers, 1.21 (95% CI, 0.65 to 2.25) for current smokers of 1 to 20 cigarettes/day, 1.35 (95% CI, 0.70 to 2.61) for current smokers of 21 to 30 cigarettes/day, and 1.82 (95% CI, 0.98 to 3.38) for current smokers of 31 or more cigarettes/day (P for trend = 0.063). The respective multivariate-adjusted relative risks for high-frequency hearing impairment compared with never smokers were 1.70 (95% CI, 0.85 to 3.40), 1.82 (95% CI, 0.92 to 3.59), 2.00 (95% CI, 0.98 to 4.08), and 2.20 (95% CI, 1.09 to 4.42) (P for trend = 0.025). As the number of pack-years of exposure increased, the risk for high-frequency hearing impairment increased in a dose-dependent manner (P for trend = 0.011), but the risk for low-frequency hearing impairment did not (P for trend = 0.172). Our results indicate that cigarette smoking is highly associated with development of high-frequency hearing impairment in Japanese male office workers.

Gene transfer of human prostacyclin synthase ameliorates monocrotaline-induced pulmonary hypertension in rats

BACKGROUND

Prostacyclin is a potent vasodilator that also inhibits platelet adhesion and cell growth. We investigated whether in vivo gene transfer of human prostacyclin synthase (PGIS) ameliorates monocrotaline (MCT)-induced pulmonary hypertension in rats.

METHODS AND RESULTS

The cDNA encoding PGIS was intratracheally transfected into the lungs of rats by the hemagglutinating virus of Japan-liposome method. Rats transfected with control vector lacking the PGIS gene served as controls. Three weeks after MCT injection, mean pulmonary arterial pressure and total pulmonary resistance had increased significantly; the increases were significantly attenuated in PGIS gene-transfected rats compared with controls [mean pulmonary arterial pressure, 31+/-1 versus 35+/-1 mm Hg (-12%); total pulmonary resistance, 0.087+/-0.01 versus 0.113+/-0.01 mm Hg x mL x min(-1) x kg(-1) (-23%), both P:<0.05]. Systemic arterial pressure and heart rate were unaffected. Histologically, PGIS gene transfer inhibited the increase in medial wall thickness of peripheral pulmonary arteries that resulted from MCT injection. PGIS immunoreactivity was intense predominantly in the bronchial epithelium and alveolar cells. Lung tissue levels of 6-keto-PGF(1alpha), a stable metabolite of prostacyclin, were significantly increased for >/=1 week after transfer of PGIS gene. The Kaplan-Meier survival curves demonstrated that repeated transfer of PGIS gene every 2 weeks increased survival rate in MCT rats (log-rank test, P:<0.01).

CONCLUSIONS

Intratracheal transfer of the human PGIS gene augmented pulmonary prostacyclin synthesis, ameliorated MCT-induced pulmonary hypertension, and thereby improved survival in MCT rats.

Lifestyle and the development of increased serum gamma-glutamyltransferase in middle-aged Japanese men

To identify the lifestyle factors responsible for increases in serum gamma-glutamyltransferase (GGT), 1014 hepatobiliary dysfunction-free (no medication for and no past history of liver disease, < or = 39 U/L of serum aspartate and/or alanine aminotransferase, and < or = 59 U/L of serum GGT) Japanese male office workers aged 35-55 years were examined annually over five successive years (average period 4.5 years, SD 1.11 years). From the Cox proportional hazards model without serum GGT at entry, significant correlates with the incidence of increased (> or = 60 U/L) serum GGT levels were the slope of body mass index (BMI), alcohol intake, cigarette smoking and coffee drinking (negative). In the model including serum GGT at entry, the slope of BMI and coffee drinking (negative) remained as significant factors for the incidence of increased serum GGT levels. From stepwise regression analyses for the slope of log serum GGT at entry, not including serum GGT in the model, significant correlates with the slope of serum GGT were, in order of relative importance, the slope of BMI, alcohol intake and coffee drinking (negative). In the model with serum GGT at entry, the slope of BMI and coffee drinking (negative) remained as statistically significant. Our results indicate that an increase in body weight is the strongest determinant for increases in serum GGT and that coffee drinking may be associated with a reduced risk of the development of increased serum GGT levels.

Effects of weight variability on cardiovascular risk factors; a study of nonsmoking Japanese male office workers

OBJECTIVE

To determine the effects of weight variability on cardiovascular risk factors.

DESIGN

Longitudinal study (followed from 1990 to 1998).

SUBJECTS

Five-hundred and eighty nonsmoking Japanese male office workers aged 25-49 y.

MEASUREMENTS

Baseline levels and slopes of seven selected cardiovascular risk factors (systolic and diastolic blood pressure, total and high-density lipoprotein cholesterol, triglyceride, uric acid and hemoglobin A1c) and body mass index (BMI) variables (baseline BMI, BMI-slope, the root mean square error (BMI-RMSE), and the BMI-slope x BMI-RMSE interaction).

RESULTS

From the multiple regression analyses, the slopes of the six cardiovascular risk factors, except hemoglobin A1c, were most strongly related to the baseline level of each cardiovascular risk factor and BMI-slope. Neither BMI-RMSE nor the interaction of BMI-RMSE with BMI-slope was related to these cardiovascular risk factor slopes. As for hemoglobin A1c, BMI-slope and the interaction of BMI-RMSE with BMI-slope were not significantly related to hemoglobin A1c slope but baseline BMI and BMI-RMSE were. Furthermore, hemoglobin A1c slope values were significantly higher among those who cycled at >4.0 kg than among those who did not.

CONCLUSION

The only cardiovascular risk factor associated with BMI variability was hemoglobin A1c. Weight variability had less or little impact on cardiovascular risk factors compared with BMI-slope and baseline BMI.

Plasma brain natriuretic peptide as a prognostic indicator in patients with primary pulmonary hypertension

BACKGROUND

Plasma brain natriuretic peptide (BNP) level increases in proportion to the degree of right ventricular dysfunction in pulmonary hypertension. We sought to assess the prognostic significance of plasma BNP in patients with primary pulmonary hypertension (PPH).

METHODS AND RESULTS

Plasma BNP was measured in 60 patients with PPH at diagnostic catheterization, together with atrial natriuretic peptide, norepinephrine, and epinephrine. Measurements were repeated in 53 patients after a mean follow-up period of 3 months. Forty-nine of the patients received intravenous or oral prostacyclin. During a mean follow-up period of 24 months, 18 patients died of cardiopulmonary causes. According to multivariate analysis, baseline plasma BNP was an independent predictor of mortality. Patients with a supramedian level of baseline BNP (>/=150 pg/mL) had a significantly lower survival rate than those with an inframedian level, according to Kaplan-Meier survival curves (P<0.05). Plasma BNP in survivors decreased significantly during the follow-up (217+/-38 to 149+/-30 pg/mL, P<0. 05), whereas that in nonsurvivors increased (365+/-77 to 544+/-68 pg/mL, P<0.05). Thus, survival was strikingly worse for patients with a supramedian value of follow-up BNP (>/=180 pg/mL) than for those with an inframedian value (P<0.0001).

CONCLUSIONS

A high level of plasma BNP, and in particular, a further increase in plasma BNP during follow-up, may have a strong, independent association with increased mortality rates in patients with PPH.

Cigarette smoking and risk for impaired fasting glucose and type 2 diabetes in middle-aged Japanese men

BACKGROUND

The contribution of cigarette smoking to development of impaired fasting glucose and type 2 diabetes remains unclear.

OBJECTIVE

To investigate the association of cigarette smoking with development of impaired fasting glucose and type 2 diabetes.

DESIGN

Prospective cohort study.

SETTING

Work site in Osaka, Japan.

PARTICIPANTS

1,266 Japanese male office workers 35 to 59 years of age who did not have impaired fasting glucose or type 2 diabetes and were not taking medication for hypertension at study entry.

MEASUREMENTS

Fasting plasma glucose levels were measured at annual health examinations from May 1994 through May 1999. Impaired fasting glucose was defined as a fasting glucose level of at least 6.1 mmol/L (110 mg/dL) but less than 7.0 mmol/L (126 mg/dL). Type 2 diabetes was defined as a fasting glucose level of 7.0 mmol/L or more or current receipt of hypoglycemic medication.

RESULTS

87 and 54 men developed impaired fasting glucose and type 2 diabetes during 5,817 and 5,937 person-years follow-up, respectively. After controlling for potential predictors of diabetes, the relative risk for impaired fasting glucose compared with never-smokers was 1.62 (95% CI, 0.85 to 3.10) for ever-smokers, 1.14 (CI, 0.58 to 2.25) for persons who smoked 1 to 20 cigarettes/d, 1.33 (CI, 0.63 to 2.80) for those who smoked 21 to 30 cigarettes/d, and 2.56 (CI, 1.32 to 4.95) for those who smoked 31 or more cigarettes/d (P for trend for current smokers only = 0.013). The respective multivariate-adjusted relative risks for type 2 diabetes compared with never-smokers were 1.08 (CI, 0.34 to 3.42), 1.88 (CI, 0.71 to 5.00), 3.02 (CI, 1.15 to 7.94), and 4.09 (CI, 1.62 to 1,029) (P for trend for current smokers only < 0.001). The number of pack-years of exposure was also positively related to development of impaired fasting glucose and type 2 diabetes (P for trend = 0.039 and 0.002, respectively). The relative risk for impaired fasting glucose and type 2 diabetes in current smokers versus never-smokers was stronger among men with a body mass index less than 242 kg/m2 than among men with a body mass index of 24.2 kg/m2 or more, although the absolute risk was greater in more obese men.

CONCLUSION

The number of cigarettes smoked daily and the number of pack-years of exposure seem to be associated with development of impaired fasting glucose and type 2 diabetes in middle-aged Japanese men.

A case of constrictive pericarditis with local thickening of the pericardium without manifest ventricular interdependence

This is the first case report of postsurgical constrictive pericarditis confined to the left ventricle in which the majority of diagnosis tests were not indicative of the disease. A 50-year-old woman with a past history of mitral valve replacement was admitted for right heart failure. Cardiac catheterization showed impaired diastolic filling but lacked the characteristic ventricular interdependence recently reported to be specific for the disease, without manifest radiological appearance of pericardial thickening. However, a new technique using magnetic resonance tagging cine revealed pericardial adhesion, limited to the left ventricle, which was confirmed during pericardiectomy. After the surgery, right heart failure and diastolic filling abnormality disappeared with restoration of normal heart pressures.

Correlation between severity of pulmonary arterial hypertension and 123I-metaiodobenzylguanidine left ventricular imaging

It remains unclear whether cardiac sympathetic nervous function is disturbed in patients with pulmonary arterial hypertension (PH) and how sympathetic dysfunction is related to PH.

METHODS

In this study, (123)I-metaiodobenzylguanidine (MIBG) imaging of the heart, which reveals the sympathetic innervation of the left ventricle, was performed in 7 healthy volunteers without cardiopulmonary disease (control subjects); 55 patients with PH, including 27 with chronic thromboembolic pulmonary hypertension (CTEPH) of major vessels; and 28 patients with primary pulmonary hypertension (PPH).

RESULTS

Cardiac (123)I-MIBG uptake, assessed as the heart-to-mediastinum activity ratio (H/M), was significantly lower in the CTEPH and PPH groups compared with that in the control group (P < 0.01). Myocardial MIBG turnover, expressed as the washout rate (WR [%]) from 15 to 240 min, was significantly higher in the CTEPH and PPH groups than that in the control group (P < 0.01). In the PPH group, H/M and WR values of MIBG correlated with the severity of pulmonary hypertension (represented by total pulmonary vascular resistance determined by right heart catheterization), the right ventricular ejection fraction determined by electron beam CT, and other variables but did not correlate well in the CTEPH group. In both groups, patients with H/M > or = 2.0 showed better cumulative survival than did those with H/M < 2.0 (P < 0.05).

CONCLUSION

Patients with PH have significant left ventricular myocardial sympathetic nervous alteration. (123)I-MIBG imaging of the heart is useful for assessing the severity of pulmonary hypertension caused by PPH or CTEPH.

Association of lifestyle with serum lipid levels: a study of middle-aged Japanese men

Cross-sectional associations between lifestyle and serum lipid levels were examined in 1591 Japanese male office workers aged 35 to 59 years in Osaka, Japan. From multiple linear regression analyses, significant correlates with low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and Log triglyceride levels and the ratio of LDL cholesterol to HDL cholesterol were, in the order of relative importance: BMI, alcohol intake (negative) and age for LDL cholesterol level; BMI (negative), cigarette smoking (negative), alcohol intake, consideration for nutritional balance, hours of brisk walking, hours of walking at an ordinary pace and physical exercise for HDL cholesterol level; BMI, cigarette smoking, consideration for nutritional balance (negative), hours of work (negative), alcohol intake and coffee drinking (negative) for Log triglyceride level; and BMI, alcohol intake (negative), cigarette smoking, consideration for nutritional balance (negative), age, hours of brisk walking (negative) and the frequency of snack intake between meals for the ratio of LDL cholesterol to HDL cholesterol. Our data suggest that obesity, cigarette smoking and snack intake between meals are atherogenic whereas alcohol consumption, consideration for nutritional balance and walking long hours, especially at a brisk pace, are anti-atherogenic in middle-aged Japanese men.

Haemodynamic correlates and prognostic significance of serum uric acid in adult patients with Eisenmenger syndrome

OBJECTIVE

To assess haemodynamic correlates and prognostic significance of serum uric acid in adult patients with Eisenmenger syndrome.

DESIGN

Retrospective observational study.

SETTING

Tertiary referral centre.

PATIENTS

94 adult patients with Eisenmenger syndrome who were diagnosed between September 1982 and July 1998.

MAIN OUTCOME MEASURES

Serum uric acid was measured in all patients, together with clinical and haemodynamic variables related to mortality.

RESULTS

Serum uric acid was raised in patients with Eisenmenger syndrome compared with age and sex matched control subjects (7.0 v 4.7 mg/dl, p < 0.0001) and increased in proportion to the severity of New York Heart Association functional class. Serum uric acid was positively correlated with mean pulmonary arterial pressure (r = 0.30, p = 0.0052) and total pulmonary resistance index (r = 0.55, p < 0.0001), and negatively correlated with cardiac index (r = -0.50, p < 0.0001). During a mean follow up period of 97 months, 38 patients died of cardiopulmonary causes. Among various clinical, echocardiographic, and laboratory variables, serum uric acid remained predictive in multivariate analysis. Kaplan-Meier survival curves based on median serum uric acid showed that patients with high values had a significantly worse survival rate than those with low values (log-lank test: p = 0.0014 in male patients, p = 0.0034 in female patients).

CONCLUSIONS

Serum uric acid increases in proportion to haemodynamic severity in adult patients with Eisenmenger syndrome and is independently associated with long term mortality.

Associations of body mass index and percentage body fat by bioelectrical impedance analysis with cardiovascular risk factors in Japanese male office workers

To determine whether body mass index (BMI, kg/m2) or percentage body fat (%BF) by bioelectrical impedance analysis (BIA) better reflects the cardiovascular risk profile, we examined the associations among BMI, %BF by BIA, and cardiovascular risk factors (systolic blood pressure (SBP), diastolic blood pressure (SBP), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), LDL-C/HDL-C ratio, and triglycerides (TG)) in 1,217 Japanese male office workers aged 25 to 59 years. From stepwise regression analyses of cardiovascular risk factors on age, BMI, alcohol intake, and cigarette smoking, significant correlates were, in the order of relative importance: age, BMI, and alcohol intake for SBP and DBP (the cumulative percentage of variation; 14.9% and 21.3%, respectively); age, BMI, and alcohol intake (negative) for LDL-C (11.0%); BMI (negative), alcohol, and cigarette smoking (negative) for HDL-C (19.9%); BMI, alcohol intake (negative), age, and cigarette smoking for LDL-C/HDL-C ratio (23.1%); and BMI, age, cigarette smoking, and alcohol intake for Log TG (21.7%). From stepwise regression analyses using %BF by BIA as an independent factor, %BF by BIA was also significantly associated with each cardiovascular risk factor, but the decrease in explained variance for each cardiovascular risk factor was 0.2-4.5%, compared with the model using BMI as an independent factor. These results suggest that BMI may better reflect blood pressure or serum lipid profile than %BF by BIA.

Predictors for the development of haemolytic uraemic syndrome with Escherichia coli O157:H7 infections: with focus on the day of illness

A large outbreak of Escherichia coli O157 infections via school lunches occurred at primary schools in 1996 in Sakai City, Japan. As many as 10,000 patients suffered from diarrhoea, haemorrhagic colitis and haemolytic uraemic syndrome (HUS). Using data on 288 inpatient school children affected by this outbreak, of whom 36 presented complete HUS and the remaining 252 tested positive for E. coli O157 culture, we attempted to identify predictors for the progression to HUS. Within the first 5 days of illness, clinical features associated with inpatients who developed HUS compared with those without HUS included a C reactive protein (CRP) level higher than 1.2 mg/dl (OR 44.26; 95% CI 5.83-336.23), a white blood cell (WBC) count greater than 11.0 x 10(9)/l (OR 5.03; 95% CI 2.13-11.87) and a temperature higher than 38.0 degrees C (OR 5.00; 95% CI 2.25-11.08). It can be concluded that these three factors are predictive factors for the development of HUS in patients with E. coli O157 infection, and patients who have two or all of these factors should be observed closely.

Improvement in exercise capacity with nitric oxide inhalation in patients with precapillary pulmonary hypertension

BACKGROUND

Patients with precapillary pulmonary hypertension (PH) exhibit a poor exercise capacity due to an impaired vasodilatory response of their pulmonary arteries. By causing the pulmonary artery to dilate, inhaled nitric oxide (NO) may allow an increase in exercise capacity in patients with PH.

METHODS AND RESULTS

On 2 separate days, 3 days apart, 14 patients with precapillary PH (10 primary PH, 4 residual PH after correction of an intracardiac shunt; age, 40+/-12 years; mean pulmonary artery pressure, 60+/-23 mm Hg) performed exercise, with and without inhalation of 20 ppm NO, on a cycle ergometer. The work rate was increased 15 W/min until their symptom-limited maximum, with breath-by-breath gas analysis. Patients were randomly and blindly selected to inhale NO on either their first or second test. Peak exercise load and anaerobic threshold tended to increase, but not significantly. Peak oxygen consumption (f1.gif" BORDER="0">O(2)) and Deltaf1.gif" BORDER="0">O(2)/DeltaW ratio increased significantly, by 18% and 22%, respectively (peak f1.gif" BORDER="0">O(2), 13.6+/-3.6 to 16.0+/-4. 1 mL. kg(-1). min(-1); Deltaf1.gif" BORDER="0">O(2)/DeltaW ratio, 5. 8+/-2.4 to 7.1+/-2.3 mL. kg(-1). min(-1). W(-1); both P<0.01). Peak f1.gif" BORDER="0">O(2) increased >10% in 12 of the 14 patients. However, respiratory quotient at peak exercise decreased from 1. 22+/-0.15 to 1.09+/-0.15 (P<0.01).

CONCLUSIONS

Inhaled NO substantially increases oxygen consumption at the same workload during exercise. This finding supports the possibility of ambulatory NO inhalation therapy in patients with precapillary PH.

Coffee consumption and decreased serum gamma-glutamyltransferase: a study of middle-aged Japanese men

The potential inverse association between coffee intake and serum gamma-glutamyltransferase (GGT) was examined in a cross-sectional study involving 1353 Japanese male office workers aged 35-59 years in Osaka, Japan. Those who had serum aminotransferases exceeding the normal range and/or who had been administered medical care for, or had a past history of, liver disease were excluded. Multiple linear regression analysis and analysis of covariance were used to control for confounding variables (age, body mass index, alcohol use, and cigarette smoking) and to examine possible interactions. From the linear regression analysis, coffee intake was inversely related to serum GGT levels independently of age, body mass index, alcohol intake, and cigarette smoking. All of the latter variables were also independently and positively associated with serum GGT levels. When the interactions between coffee and each of four covariates on serum GGT were evaluated by adding each interaction term to the above regression model, significant negative interactions were observed for age and cigarette smoking. From the analysis of covariance, lower levels of serum GGT associated with coffee consumption were more evident in the older age group and at the higher levels of cigarette smoking. These findings suggest that coffee consumption is inversely related to serum GGT and that coffee may inhibit the inducing effects of aging and possibly of smoking on serum GGT in the liver.

Relation of body weight change to changes in atherogenic traits; a study of middle-aged Japanese obese male office workers

We examined the effect of body weight change on the modification of atherogenic risk factors in 296 middle-aged obese male office workers without medication for hypertension, dyslipidemia, hyperuricemia or diabetes mellitus. During a 1-year education program, 39.2% of the participants could reduce their weight, and the percentage of those who lost 2 kg or more was only 17.7%. Concomitant with the decrease of weight, however, the levels of systolic and diastolic blood pressures, total cholesterol, triglyceride, uric acid and hemoglobin A1c and the ratio of total cholesterol to high-density lipoprotein (HDL) cholesterol decreased significantly, whereas the HDL cholesterol level increased significantly. In a multivariate regression analysis, in addition to the initial risk-factor level, weight change was an important factor determining the changes in atherogenic risk factors. Changes in alcohol consumption were significantly associated with the changes in systolic blood pressure and HDL cholesterol levels. Changes in cigarettes smoking also showed significant associations with the changes in triglyceride level and the ratio of total cholesterol to HDL cholesterol. These results suggest that although the education program for controlling weight may have limited success, weight reduction exhibits beneficial changes in the atherogenic risk-factor profile in middle-aged obese men.

Hemodynamic, renal, and hormonal effects of adrenomedullin infusion in patients with congestive heart failure

BACKGROUND

Experimental studies have shown that adrenomedullin (AM) causes vasodilatation, diuresis, and a positive inotropic effect. In humans, however, whether infusion of AM has beneficial effects in congestive heart failure (CHF) remains unknown.

METHODS AND RESULTS

Hemodynamic, renal, and hormonal responses to intravenous infusion of human AM (0.05 microg. kg(-1). min(-1)) were examined in 7 patients with CHF and 7 normal healthy subjects (NL). In NL group, AM significantly decreased mean arterial pressure (-16 mm Hg, P<0. 05) and increased heart rate (+12 bpm, P<0.05). In CHF group, AM also decreased mean arterial pressure (-8 mm Hg, P<0.05) and increased heart rate (+5 bpm, P<0.05), but to a much lesser degree (P<0.05 versus NL). AM markedly increased cardiac index (CHF, +49%; NL, +39%, P<0.05) while decreasing pulmonary capillary wedge pressure (CHF, -4 mm Hg; NL, -2 mm Hg, P<0.05). AM significantly decreased mean pulmonary arterial pressure only in CHF (-4 mm Hg, P<0.05). AM increased urine volume (CHF, +48%; NL, +62%, P<0.05) and urinary sodium excretion (CHF, +42%; NL, +75%, P<0.05). Only in CHF, plasma aldosterone significantly decreased during (-28%, P<0.05) and after (-36%, P<0.05) AM infusion. These parameters remained unchanged in 7 patients with CHF and 6 healthy subjects who received placebo.

CONCLUSIONS

Intravenous infusion of AM has beneficial hemodynamic and renal effects in patients with CHF.

Clinical correlates and prognostic significance of six-minute walk test in patients with primary pulmonary hypertension. Comparison with cardiopulmonary exercise testing

The six-minute walk test is a submaximal exercise test that can be performed even by a patient with heart failure not tolerating maximal exercise testing. To elucidate the clinical significance and prognostic value of the six-minute walk test in patients with primary pulmonary hypertension (PPH), we sought (1) to assess the relation between distance walked during the six-minute walk test and exercise capacity determined by maximal cardiopulmonary exercise testing, and (2) to investigate the prognostic value of the six-minute walk test in comparison with other noninvasive parameters. The six-minute walk test was performed in 43 patients with PPH, together with echocardiography, right heart catheterization, and measurement of plasma epinephrine and norepinephrine. Symptom-limited cardiopulmonary exercise testing was performed in a subsample of patients (n = 27). Distance walked in 6 min was significantly shorter in patients with PPH than in age- and sex-matched healthy subjects (297 +/- 188 versus 655 +/- 91 m, p < 0. 001). The distance significantly decreased in proportion to the severity of New York Heart Association functional class. The distance walked correlated modestly with baseline cardiac output (r = 0.48, p < 0.05) and total pulmonary resistance (r = -0.49, p < 0. 05), but not significantly with mean pulmonary arterial pressure. In contrast, the distance walked correlated strongly with peak V O(2) (r = 0.70, p < 0.001), oxygen pulse (r = 0.57, p < 0.01), and V E-VCO(2) slope (r = -0.66, p < 0.001) determined by cardiopulmonary exercise testing. During a mean follow-up period of 21 +/- 16 mo, 12 patients died of cardiopulmonary causes. Among noninvasive parameters including clinical, echocardiographic, and neurohumoral parameters, only the distance walked in 6 min was independently related to mortality in PPH by multivariate analysis. Patients walking < 332 m had a significantly lower survival rate than those walking farther, assessed by Kaplan-Meier survival curves (log-rank test, p < 0.01). These results suggest that the six-minute walk test, a submaximal exercise test, reflects exercise capacity determined by maximal cardiopulmonary exercise testing in patients with PPH, and it is the distance walked in 6 min that has a strong, independent association with mortality.

Lifestyle and serum gamma-glutamyltransferase: a study of middle-aged Japanese men

The association of lifestyle factors with serum gamma-glutamyltransferase (GGT) was examined in 1176 Japanese male office workers aged 40-59 years. Those who had serum aminotransferase levels exceeding the normal range and/or who took prescription medication for, or had a past history of, liver disease were excluded. From the logistic regression analysis, lifestyle factors showing a positive association with high serum GGT (> or = 60 U/l) were body mass index, alcohol intake, cigarette smoking, and snacking between meals. On the other hand, coffee drinking showed an inverse association with high serum GGT. As for the relationships between snacking between meals and other lifestyle factors, snacking between meals was significantly related to alcohol intake (negative) and coffee drinking. Influences of snacking between meals on serum GGT are likely to be indirectly mediated through coping mechanisms of less alcohol drinking and more coffee drinking. Our findings support the conclusions that alcohol drinking, obesity, and cigarette smoking are positively associated with raised serum GGT and that coffee consumption is inversely related to raised serum GGT.

Effects of coffee consumption against the development of liver dysfunction: a 4-year follow-up study of middle-aged Japanese male office workers

The association of coffee consumption with the development of increased serum aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) activities over 4 years was studied in 1221 liver dysfunction-free (serum AST and ALT < or = 39 IU/l and no medical care for or no past history of liver disease) Japanese male office workers aged 35 to 56 years. From the analysis using the Kaplan-Meier method, the estimated incidence of serum AST and/or ALT > or = 40 IU/l, > or = 50 IU/l, and > or = 60 IU/l decreased with an increase in coffee consumption. From the Cox proportional hazards model, coffee drinking was independently inversely associated with the development of serum AST and/or ALT > or = 40 IU/l (p = 0.019 by test for tendency), > or = 50 IU/l (p = 0.002), and > or = 60 IU/l (p = 0.007), controlling for age, body mass index, alcohol intake, and cigarette smoking. These results suggest that coffee may be protectively against the liver dysfunction in middle-aged Japanese men.

Rapid turnover of tryptophan hydroxylase is driven by proteasomes in RBL2H3 cells, a serotonin producing mast cell line

Previously we demonstrated that tryptophan hydroxylase (TPH) undergoes very fast turnover driven by ATP-dependent proteolysis in serotonin producing mast cells [Hasegawa et al. (1995) FEBS Lett. 368, 151-154]. We searched for the major proteases involved in the rapid degradation of TPH in RBL2H3 cells. Among various protease inhibitors tested, proteasome inhibitors MG115, MG101, MG132, and lactacystin effectively inhibited the intracellular degradation of TPH. Administration of the proteasome inhibitors to cultured cells caused more than a 5-fold accumulation of TPH. Administration of the inhibitors together with cycloheximide stabilized the amount of TPH with no appreciable increase or decrease. Although MG-series proteasome inhibitors could inhibit calpain, the involvement of calpain was excluded since the cysteine protease inhibitor E-64-d, which acts on calpain, had no effect. Extracts of RBL2H3 cells were shown to contain a protease that digests TPH in an ATP-dependent manner and is sensitive to proteasome inhibitors. The ubiquitination of TPH could be visualized by Western blot analysis using both anti-TPH and anti-ubiquitin antibodies. Based on these results, we conclude that 26S proteasomes are mainly involved in the degradation of TPH. In the reported amino acid sequences of TPH from various sources including human, rabbit, rat, and mouse, a PEST sequence that is widely shared among short-lived proteins has been recognized. It was noted that the PEST sequence lies within the most conserved portion of the enzyme, the pteridine binding site.

Effect of early fosfomycin treatment on prevention of hemolytic uremic syndrome accompanying Escherichia coli O157:H7 infection

OBJECTIVE

To clarify the effect of early fosfomycin treatment, an antimicrobial agent in common use in Japan, on children with E. coli O157 with the aim of preventing hemolytic uremic syndrome (HUS).

PATIENTS AND METHODS

DESIGN

Non-randomized prospective study for development of HUS among inpatients with E. coli O157.

SETTING

The hospitals where the 292 inpatients were treated.

CASES

A total of 292 inpatients aged six to eleven years with E. coli O157 infection, 36 (12.3%) of whom were HUS cases.

RESULTS

Most of the HUS inpatients (91.7%) developed this complication between the sixth and ninth day of illness. We therefore analyzed the effects of antimicrobial therapy, especially that of fosfomycin, on prevention of HUS within the first five days of illness, because fosfomycin was the most frequently used (88.0%). To clarify the effect of fosfomycin alone on prevention of HUS, we carried out an analysis using the data for 130 inpatients who received fosfomycin alone or did not receive any antimicrobial agents, within the first five days of illness. multivariate analysis, controlled for age, gender and presence of fever, showed that all adjusted odds ratios for the development of HUS with the use of fosfomycin within the first three days of illness were less than 1.0, with the use of fosfomycin on the second day of illness achieving statistical significance (adjusted OR, 0.09; 95% CI, 0.01-0.79). Furthermore, inpatients who took fosfomycin within the first two days of illness developed HUS significantly less often than those who did not (adjusted OR, 0.15; 95% CI, 0.03-0.78). On the other hand, fosfomycin therapy on and after the third day of illness was not associated with the prevention of HUS.

CONCLUSION

The early use of fosfomycin within the first two days of illness might prevent the development of HUS.

Abnormality of left ventricular sympathetic nervous function assessed by (123)I-metaiodobenzylguanidine imaging in patients with COPD

BACKGROUND

Cardiac and systemic autonomic nervous function may be impaired in patients with COPD. Few reports, however, have described sympathetic nervous function of the left ventricle (LV) in COPD patients.

STUDY OBJECTIVE

To assess the LV sympathetic nervous function in patients with COPD using (123)I-metaiodobenzylguanidine (MIBG) imaging of the heart.

DESIGN

Prospective comparison of (123)I-MIBG imaging results in COPD patients and normal subjects.

PARTICIPANTS

Twenty-eight patients with COPD without manifest right ventricular overload and 7 volunteers without cardiopulmonary disease (control subjects).

MEASUREMENTS

(123)I-MIBG imaging results and plasma norepinephrine concentration were compared between the COPD and control groups. In the COPD group, pulmonary function tests were performed and all subjects were interviewed about their symptoms.

RESULTS

(123)I-MIBG uptake, assessed as the cardiac to mediastinal activity ratio in the delayed image, was significantly lower in the COPD group than in the control group (p < 0.05). (123)I-MIBG turnover, expressed as the washout rate (WR) of (123)I-MIBG from 15 to 240 min, was significantly higher in the COPD group than in the control group (p < 0.01). In the COPD group, patients with dyspnea showed lower cardiac to mediastinal activity ratios and higher WRs compared with patients who had mild dyspnea. The WR correlated negatively with the vital capacity/predicted value ratio, correlated negatively with the maximal voluntary ventilation volume/predicted value ratio, and correlated positively with the residual volume/total lung capacity ratio in the COPD group. The plasma norepinephrine concentration in COPD patients was higher than that in the control subjects.

CONCLUSION

Patients with COPD have significant sympathetic nervous impairment of the LV myocardium as a result of generalized sympathetic overactivity.