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Biomedical subjects

Minoru Yamakado

Publications and source records attributed to Minoru Yamakado.

25 records · Page 2Linked to original sources
PubMed2002

Increased prevalence of carotid atherosclerosis in hepatitis B virus carriers.

BACKGROUND: Recent experimental and epidemiological findings suggest that some infectious agents play a role in the development and promotion of atherosclerosis. We have investigated the possible association between hepatitis B virus surface antigen (HBsAg) positivity and carotid arteriosclerosis. METHODS AND RESULTS: In this cross-sectional cohort study, we analyzed data from subjects undergoing general health-screening tests, including both high-resolution B-mode carotid ultrasound and assessment of HBsAg status, between 1994 and 2001 at our institute. Of the 4686 study subjects (3137 men and 1549 women; age 22 to 88 years), 1294 (28%) had carotid artery plaque and 40 (0.9%) were positive for HBsAg, indicating they were hepatitis B virus carriers. No HBsAg-positive subjects were positive either for antibodies against the hepatitis C virus (HCV) or for HCV core proteins. Univariate analysis revealed HBsAg positivity was associated with carotid plaque with an odds ratio of 1.58 (95% CI, 1.14 to 2.19, P<0.05). When other confounding risk factors for atherosclerosis were included as covariates in the statistical analysis, HBsAg positivity was still positively associated with carotid plaque with an odds ratio of 1.57 (95% CI, 1.10 to 2.24, P<0.05). CONCLUSIONS: These findings suggest a possible role of chronic hepatitis B infection in the pathogenesis of carotid arteriosclerosis.

Adult↗
PubMed2002

Association between hepatitis C virus seropositivity, carotid-artery plaque, and intima-media thickening.

We investigated the relation between positivity for hepatitis C virus (HCV) and carotid-artery plaque and carotid intima-media thickening by analysing cross-sectional data of individuals undergoing a general health screening test. Of 4784 individuals enrolled, 104 (2.2%) were seropositive for HCV. After adjustment for confounding risk factors, HCV seropositivity was found to be associated with an increased risk of carotid-artery plaque (odds ratio 1.92 [95% CI 1.56-2.38], p=0.002) and carotid intima-media thickening (2.85 [2.28-3.57], p<0.0001). These findings suggest a possible role for chronic hepatitis C in the pathogenesis of carotid arterial remodelling.

Adult↗
PubMed2002

Blood sugar control reverses the increase in urinary excretion of prostaglandin D synthase in diabetic patients.

BACKGROUND/AIMS: We investigated basal levels of serum and urinary lipocalin-type prostaglandin D synthase/beta-trace (L-PGDS) in type-2 diabetic patients and explored whether glycemic control affects L-PGDS status in another 55 diabetic inpatients with normoalbuminuria. METHODS: Fifty-five type-2 diabetic outpatients (HbA1c, 9.14 +/- 0.20%; creatinine (Cr), 85.1 +/- 2.4 micromol/l), and 55 age-matched healthy control subjects were recruited. Serum and urinary levels of L-PGDS were determined with respect to the stage of diabetic nephropathy. The L-PGDS was localized by immunohistochemistry. RESULTS: The urinary L-PGDS index increased in diabetic patients, compared with the controls (234.8 +/- 27.4 vs. 73.8 +/- 7.8 microg/mmol Cr, p < 0.001). Even in normoalbuminuric patients as well as in microalbuminuric patients, urinary L-PGDS indexes were higher than the controls (166.0 +/- 21.1, p < 0.0001 and 338.6 +/- 62.5 microg/mmol Cr, p < 0.0001, respectively), although the serum L-PGDS level was equal to that in the control subjects. Multiple regression analysis revealed that the urinary L-PGDS index was predicted solely by glucose levels and type-IV collagen index, whereas the serum L-PGDS was determined mainly by age and serum Cr. Glycemic control reduced the urinary L-PGDS index towards the normal range in diabetic patients with normoalbuminuria (172.3 +/- 6.6 vs. 118.1 +/- 2.6 (SE) microg/mmol Cr, p < 0.0001). Immunohistochemistry showed that L-PGDS was uniquely present in the renal tubules in diabetes while in nondiabetics, L-PGDS occurred solely in the peritubular interstitium, not in the tubular cells. CONCLUSION: Inadequate glycemic control is responsible for urinary L-PGDS excretion in the diabetic patients. Urinary L-PGDS is useful to predict subclinical renal injury associated with type-2 diabetes.

Adult↗
PubMed2002

Lipocalin-type prostaglandin d synthase in essential hypertension.

Lipocalin-type prostaglandin D synthase (L-PGDS) reportedly well predicts cardiovascular injuries in humans. However, little is known about the implications of L-PGDS in hypertension. In the present study, we investigated the alterations of serum and urinary L-PGDS in hypertensive patients with or without renal dysfunction. A total of 111 patients with hypertension (EHT; 65 with normoalbuminuria, 23 with microalbuminuria, 12 with macroalbuminuria, 11 with renal failure) and 102 normotensive, nomoalbuminuric subjects (NT) were studied. L-PGDS was measured by enzyme-linked immunosorbent assay, and L-PGDS in the kidney was localized using immunohistochemical methods. Blood pressure was higher in EHT groups than in the NT group (P<0.0001). There were no differences in age, gender, BMI, TC, TG, and HbA1c levels among the groups. Serum creatinine and urinary albumin levels were higher in the group with renal failure. Serum levels of L-PGDS were increased in EHT with normoalbuminuria, as compared with NT (0.88 +/- 0.05 versus 0.65 +/- 0.02 microg/mL; P<0.001). Serum levels of L-PGDS increased with the renal function worsened and positively correlated with serum creatinine, particularly in patients with renal impairments (r=0.76, P<0.0001). Similarly, the urinary L-PGDS excretions in EHT with normoalbuminuria were higher than that in NT (2.31 +/- 0.29 versus 1.16 +/- 0.14 mg/gCr, P<0.001), whereas there were no differences in urinary albumin excretion between the 2 groups. Moreover, urinary L-PGDS excretion increased dramatically with an increase in albuminuria or proteinuria. L-PGDS was stained in the tubules and the interstitium of the kidney in nephrosclerosis. In conclusion, patients with hypertension exhibited a higher level of L-PGDS in serum and urine, and this became increasingly obvious along with advance in renal dysfunction. These data suggest that L-PGDS metabolism is related to blood pressure and kidney injuries associated with hypertension.

Carrier Proteins↗
PubMed2002

Serum calcium concentration and carotid artery plaque: a population-based study.

OBJECTIVES: Serum calcium level may be associated with the morbidity and mortality of cerebrovascular and cardiovascular diseases. However, only a few large-scale population studies have been performed to investigate the association between serum calcium and carotid plaque. METHODS: A retrospective cross-sectional study was performed on the subjects who underwent general health screening tests including ultrasonographic evaluation of the carotid artery between 1994 and 2000 at our institute. Before the statistical analysis, all serum calcium values were adjusted for the serum albumin concentration. RESULTS: Of 5,732 subjects enrolled in the present study, 3,785 were male and 1,947 were female, and were aged 22-88 years (median 57 years). Carotid plaque was identified in 1,313 (23%) subjects. Serum calcium concentration was slightly greater in the subjects with plaque than in those without (2.28 +/- 0.8 vs 2.27 +/- 0.7 mmol/l, p < 0.001; unpaired t-test). Multivariate logistic regression analysis including confounding risk factors revealed that serum calcium is an independent positive predictor for carotid plaque with an odds ratio of 1.70 [95% confidence interval (CI): 1.50-1.92] for each increase of 1 mg/dl. Male and female subjects in the highest quartiles of serum calcium concentrations had a greater risk of carotid plaque with odds ratios of 1.52 (95% CI 1.35-1.71, p < 0.01) and 1.57 (95% CI 1.27-1.92, p < 0.05), respectively, compared to the subjects in the lowest quartiles of calcium concentrations. CONCLUSIONS: These findings indicate that serum calcium is an independent risk factor for carotid plaque.

Adult↗
PubMed2002

[Protective vascular effect of angiotensin receptor blocker (ARB)].

To determine the mechanism of protective vascular effect of angiotensin receptor blocker(ARB), the effect of candesartan on blood pressure(BP), ultrasonographically assessed carotid intima-media thickness(IMT), plasma superoxide dismutase activity (SOD), and lipid peroxides(LPO) were measured, and compared with the effects of diuretics in 20 patients with essential hypertension. Candesartan significantly reduced BP similarly with diuretics. However, IMT was significantly reduced by candesartan, but not by diuretics. Also, candesartan increased SOD, and decreased LPO. There were significant relationship between changes in IMT and SOD, and LPO. These results suggest that protective vascular effect of ARB may be through its effect on angiotensin induced oxidative stress independent of BP reduction.

Angiotensin Receptor Antagonists↗