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Biomedical subjects

M Ohtaka

Publications and source records attributed to M Ohtaka.

89 records · Page 5Linked to original sources

Systemic and pulmonary effects of nitroprusside during mitral valve replacement in patients with mitral regurgitation.

The effects of sodium nitroprusside on the systemic and pulmonary circulation were assessed in 17 patients with severe mitral regurgitation (MR) during mitral valve replacement. In nine patients, MR was related to rheumatic heart disease, in six resulted from acute myocardial infarction, and in two was due to subacute bacterial endocarditis. Nitroprusside was administered intraoperatively at an infusion rate of 10 to 65 mcg/min. During vasodilation therapy, forward stroke volume increased from 34 +/- 2.8 to 46 +/- 4.8 ml, while left ventricular filling pressure decreased from 28.7 +/- 1.9 to 20.6 < or = 1.8 mm Hg. There was a significant decrease in systemic vascular resistance (from 2379 +/- 204 to 1646 +/- 161 dynes.sec.cm-5) and mean arterial pressure (from 89.8 +/- 4 to 78.1 +/- 5 mm Hg). Similarly, a significant decrease was observed in both pulmonary vascular resistance (from 414 +/- 45 to 208 +/- 31 dynes.sec.cm-5) and mean pulmonary arterial pressure (from 42.5 +/- 2.5 to 29.7 +/- 2.5 mm Hg) with nitroprusside. In all patients there was a decrease in the magnitude of the peak V wave of the pulmonary capillary wedge pressure (from 45.2 +/- 3.9 to 26.1 +/- 3.1 mm Hg). These findings suggest that judicious intraoperative administration of nitroprusside improves right and left ventricular function in patients with MR undergoing mitral valve replacement, by increasing forward stroke volume while decreasing ventricular filling pressures and vascular resistance (preload and afterload).

Blood Pressure↗

Importance of hypertension and genetic factors for atherogenesis in rats.

1. A new experimental system has been used to analyse factors involved in the initiation of atherosclerosis in rats. 2. Arterial fat deposition in the cerebral arteries was affected by blood pressure, serum cholesterol concentrations, strain difference and age, of which high blood pressure was the most important. 3. A genetic factor independent of hypertension was shown to be involved in acute arterial fat deposition in spontaneously hypertensive rats.

Age Factors↗

Vectorcardiographic study on left ventricular hypertrophy in spontaneously hypertensive rats.

To observe cardiac changes in spontaneously hypertensive rats (SHR) functionally, the vectrocardiographic approach was tried, applying the Takayasu lead system to rats. This vectrocardiogram (VCG) was shown to be sufficiently good to detect left ventricular hypertrophy (LVH) in SHR. VCG in SHR showed specific features, some of which were left upward deviation of the maximum QRS vector in the frontal plane, an increased magnitude of the maximum spatial QRS vector, and prolongations of such indices as the QRS duration, time to the maximum spatial QRS vector and QT interval with abnormal ST-T changes. The P wave of SHR in the X scalar electrocardiogram, lower and wider than that of Wistar-Kyoto rats may also be a significant feature of LVH in SHR. The angle of the maximum QRS vector in the horizontal plane was not proven to be a suitable index of LVH in SHR. Most of the histometrical findings were closely correlated to blood pressure. Some of the vectrocardiographic findings were significantly correlated both to blood pressure and to some of the characteristic findings of LVH, such as the weights of the heart and the left ventricle and so forth. This experiment also indicated that LVH in SHR was not limited only to quantitative myocardial hypertrophy. It also seemed to be related to reversible or irreversible qualitative changes of coronary arteries or myocardium, such as myocardial fibrosis. This vectrocardiographic method was shown to be useful in obtaining various information about the cardiovascular system in rats, especially in SHR, and it seemed to be helpful for further understanding hypertensive cardiac diseases in humans.

Animals↗

Appendiceal mucocele: sonographic findings.

BACKGROUND: Appendiceal mucocele (AM) is a relatively rare disease, and its sonograms (US) have not been sufficiently analyzed. METHODS: We studied the US findings of five patients with AM, with special attention to AM size, shape, internal echoes, and the mode of back echoes. RESULTS: All five cases showed an elongated mass in the lower right abdomen. Internal echoes were present in all cases and M-mode US confirmed the movement of those echoes. The echogenecity of the lesion changed according to the frequency of the transducer used. Only one case showed posterior echo enhancement, and no case showed lateral shadowing. CONCLUSION: AM appears as an elongated echo-poor mass without posterior echo enhancement. The cyst wall is less distinct than what one would expect for a cyst. When encountering such a mass in the lower right abdomen, one should strongly suspect an AM. In such cases, appropriate diagnostic and therapeutic strategies are especially necessary to prevent rupture that results in development of pseudomyxoma peritonei.

Aged↗

Iloprost decreases urinary albumin excretion rate in patients with diabetic nephropathy.

We conducted an open clinical trial to determine whether administration of iloprost, a stable prostacyclin analog, has any effect on urinary albumin excretion and other parameters associated with non-insulin-dependent diabetes mellitus (NIDDM) patients. Twenty-three NIDDM patients with nephropathy were divided into groups A and B which were matched in terms of sex, age, duration of diabetes and blood glucose control. After 2 weeks of observation, 11 patients in group A received an intravenous infusion of iloprost (10 micrograms at a rate of 0.075 microgram/kg per h) once daily for 2 weeks, while 12 untreated diabetic patients in group B served as controls. In group A, iloprost significantly reduced the urinary albumin excretion rate, the urinary albumin-creatinine ratio and N-acetyl-beta-D-glucosaminidase without decreasing creatinine clearance during the treatment period (P < 0.05, respectively). However, none of these parameters changed significantly in group B. Urinary beta 2-microglobulin, blood pressure, heart rate, serum electrolytes, BUN and serum creatinine were not significantly altered by iloprost during the treatment period. Side effects associated with iloprost were mild and could be ameliorated by slowing the infusion rate. We conclude that iloprost appears to be safe and has an apparent effect on the urinary albumin excretion rate and N-acetyl-beta-D-glucosaminidase.

Albuminuria↗

Interrelationships between blood pressure, sodium, potassium, serum cholesterol, and protein intake in Japanese.

Interrelationships among blood pressure (BP), sodium (Na), potassium (K), dietary protein, and serum cholesterol level (Chol) were examined in 62% (1120) of 1818 Japanese inhabitants of both sexes aged over 30 years who lived in a rural village in Japan. Fasting single-spot urine specimens were collected in the morning to measure Na, K, urea nitrogen (UN), inorganic sulfate (SO4), and creatinine (Cr). The Cr ratios of Na, K, UN, SO4, Na/K, and SO4/UN were analyzed by multiple regression analysis to determine independent associations with BP together with age, obesity index, hematocrit (Hct), Chol, triglyceride (TG), and fasting serum glucose level (Glu). Except for Na/Cr in men, Na/Cr and Na/K were found to be independently and positively related to BP, particularly to systolic BP (SBP). In contrast, K/Cr and SO4/UN (an index related to the dietary score of sulphur-containing amino acids derived mainly from animal protein) were both negatively associated with SBP, and UN/Cr (an index of total protein intake) was positively associated with SBP in men. Chol was linked to BP negatively in men but positively in women. Age, obesity index, TG, and Hct were generally positively and significantly related to BP in both sexes. The results confirmed on epidemiological grounds the positive link of Na and the negative link of K to BP within a single population in Japan. They further suggest, although only in men, that there is a negative relationship of Chol and dietary animal protein with BP.

Adult↗

Case of ulcerative colitis associated with oesophageal ulcer.

A case of ulcerative colitis complicated by oesophageal ulcers is reported. A woman was admitted to our hospital because of exacerbations of ulcerative colitis both in 1992 (aged 15 years) and 1995 (aged 18 years). When she was admitted in 1995 she complained of bloody diarrhoea, sore throat and pain on swallowing. Oesophagogastro-duodenoscopy revealed oesophageal ulcers. Oesophageal pH monitoring (24-h) showed no evidence of gastro-oesophageal reflux disease. After the patient was treated she with oral prednisolone showed considerable improvement clinically and endoscopically. Initial dosage was 60 mg/day, and 1 week later, the dosage was gradually dropped since the patient responded favourably. The improvement of the oesophageal lesions coincided with the remission of ulcerative colitis. The oesophageal ulcers are, therefore, thought to be an extracolonic manifestation of ulcerative colitis.

Adolescent↗