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Biomedical subjects

K Naitoh

Publications and source records attributed to K Naitoh.

79 records · Page 5Linked to original sources
PubMedDate not supplied

Chronic oral toxicity of a synthetic antioxidant, 2,2'-methylenebis(4-ethyl- 6-tert-butylphenol), in rats.

Groups of 30 Wistar rats of each sex were treated with 2,2'-methylenebis(4-ethyl-6-tert-butylphenol) (MBEBP) in the diet at levels of 0, 0.03, 0.1 and 0.3% for up to 18 months. In both sexes, survival rates of treated groups were similar to those of the controls. Body weight gain was depressed (0.3% group in males, 0.1 and 0.3% groups in females). Slight anaemia (0.3% groups in both sexes) and increase of blood urea nitrogen (0.3% groups in both sexes) were observed. Histopathologically, vacuolization of the parathyroid gland cells (0.3% group in males and all treated groups in females) and degenerative changes of the kidney (0.1 and 0.3% groups in males) were observed. No neoplastic responses following MBEBP administration were noted. From these results, the no-observed-adverse-effect level (NOAEL) for MBEBP toxicity was estimated as 12 mg kg-1 body wt. day-1 in male rats. In female rats, the lowest-observed-adverse-effect level (LOAEL) was estimated as 15 mg kg-1 body wt. day-1.

Animals↗
PubMedDate not supplied

Systemic hypertension as a risk factor for complications with an aortic mechanical valve.

We sought to determine the effect of preoperative systemic hypertension on prosthesis related complications or postoperative aortic dissection after valve replacement in patients with aortic regurgitation. The patients were divided into two groups according to the presence or absence of systemic hypertension: Group I, with hypertension (n = 35), and Group II, without hypertension (n = 37). The survival rate and event free rate were examined for 72 patients who were alive 30 days after valve replacement with a St. Jude Medical valve for aortic regurgitation. The cumulative 10 year survival rate of Group I (65% +/- 12%) was lower than that of Group II (79% +/- 15%). The 10 year event free rate of all prosthesis related complications was 62% +/- 13% in Group I, and 96% +/- 3% in Group II (p < 0.05). The 10 year event free rate for ascending aortic dissection was 73% +/- 12% in Group I and 100% in Group II (p < 0.05). The linearized event rate of all prosthesis related complication was 3.8% per patient-year in Group I and 0.5% per patient-year in Group II. In conclusion, systemic hypertension was a risk factor for prosthesis related complications and for complicated aortic lesions after aortic valve replacement. Careful postoperative management for hypertension is necessary in patients with systemic hypertension after aortic valve replacement. Tissue valves may be recommended in patients with aortic valve disease and severe hypertension.

Aortic Valve↗
PubMedDate not supplied

Menopause and hyperlipidemia: pravastatin lowers lipid levels without decreasing endogenous estrogens.

In study 1, serum lipid and estrogen levels were determined in 30 women (aged 40 to > 60 years). Total cholesterol (TC) levels increased significantly with age, but no significant association was found between TC levels and menopausal status. Hypercholesterolemia (TC > 220 mg/dl) was identified in 10 women and hypertriglyceridemia (> 150 mg/dl) in 5 women. Among women not receiving estrogen replacement therapy, a significant negative correlation was found between TC levels and estradiol-17 beta levels. In study 2, serum lipid and estrogen levels were determined in 74 women; 12 of the 74 were receiving conjugated estrogen for the treatment of the menopausal syndrome and 21 hyperlipidemic women were receiving pravastatin (2.5 to 30 mg daily). Among postmenopausal women, high-density lipoprotein cholesterol levels were significantly higher and low-density lipoprotein (LDL) cholesterol levels significantly lower in the estrogen-treated than untreated women. Serum TC and LDL cholesterol levels were significantly reduced during pravastatin treatment. Levels of endogenous estrogens (estradiol-17 beta, estrone, and estrone sulfate) were not significantly affected by pravastatin treatment. The results indicate that pravastatin can be used to reduce hyperlipidemia in menopausal women without affecting endogenous estrogen levels.

Adult↗
PubMedDate not supplied

Surgical treatment of isolated iliac artery aneurysm with ureteral obstruction and/or renal failure.

Three patients with isolated iliac artery aneurysm with ureteral obstruction and/or renal failure are presented. One patient had a stenotic lesion of the right ureter caused by direct compression of common and internal iliac artery aneurysms. Resection of the aneurysms and graft replacement were successfully performed. The other patients, who had hydroureteronephrosis and renal failure caused by entrapment of the ureters in perianeurysmal fibrosis, were treated surgically by ureterolysis, resection with graft replacement of the common iliac artery aneurysms, and endoaneurysmorraphy of the internal iliac artery aneurysms. One has had a good postoperative course, whereas the other died from a rare complication of rectosigmoid colon perforation caused by direct compression by the graft.

Acute Kidney Injury↗