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Biomedical subjects

H Ohara

Publications and source records attributed to H Ohara.

At least 127 records · Page 7Linked to original sources
PubMed1990

Caffeine consumption among medical students.

Recently, caffeine consumption in Japan is thought to have increased. Although caffeine had been considered to be harmless, there have been studies which suggests an association between caffeine and health and give rise to vigorous discussion. However, in Japan, there have been few epidemiological studies on caffeine consumption among a general population. A questionnaire survey was conducted among medical students and the results were as follows: 1) High dose users (estimated daily caffeine use is 250 mg or more) were observed in 15.2% and the proportion was higher in males than in females. 2) The respondents gave sleepiness, dry mouth and so on, as reasons for taking caffeine beverages, and gave, as the effects of caffeine, becoming clear-headed, shaking off sleepiness, and epigastric discomfort or pain. 3) A third of respondents have experienced taking caffeine tablets and ampules to shake off sleepiness and, in males, the more caffeine they had daily, the more who reported the experience. 4) Caffeine consumption has an association with alcohol use and smoking habit among males.

Adult↗
PubMed1990

Caffeine consumption and anxiety and depressive symptomatology among medical students.

Caffeine is one of the most widely consumed psychoactive substances in the world and is ingested in a variety of favorites, such as coffee, tea, cola and so on. Although it has been suggested that high dose caffeine users have more anxiety and depressive symptoms than low users, this relationship is not clear in Japan, where caffeine consumption is considered to be less than in Western countries. A questionnaire survey was conducted among medical students and 291 out of 423 initial subjects completed it. Among males, caffeine consumption was significantly and positively correlated with anxiety symptoms, when alcohol use and smoking habit were adjusted. However, there was no relationship between caffeine consumption and depressive symptoms. Among females, although there was no association between caffeine consumption and anxiety symptoms, high dose caffeine users showed less depressive symptoms than moderate and low users, when alcohol use was adjusted. It is suggested that caffeine use is one of the important factors, in researching psychological health among the general population. We need further epidemiological studies to determine whether there is a causal relationship between caffeine and psychological ill health or not.

Adult↗
PubMed1990

[Isolation of children with attention deficit disorder in their classrooms].

The isolation of children with attention deficit disorder (ADD) among peers was examined by conducting sociometric tests in 28 classrooms to which ADD children belonged. The conclusions are as follows: 1. Among ADD children, 39.3% were classified as isolated children who received no Social Choice votes, a proportion that was significantly higher than normal controls. 2. Results suggests that isolation was correlated with such characteristics of ADD children as higher grade in school, later first consultation and lower IQ levels. 3. Classroom characteristics which correlated with isolation of ADD children were larger number of children per class and stronger class cohesion. It is thought that reducing the number of children in each class will be effective in preventing isolation of ADD children. 4. The possibility of an association between assessment of parents for social relationships of ADD children and their isolation exists and needs to be assessed. The authors emphasize the need for ADD children to have support in their interpersonal relationships, and discuss ways of intervention to prevent their being isolated in their classrooms.

Age Factors↗
PubMed1990

[Malignant fibrous histiocytoma arising from the renal capsule: report of a case].

Malignant fibrous histiocytoma (MFH) is now considered the most common soft tissue sarcoma in adults, but MFH arising from the renal capsule is very rare. A 77-year-old woman was admitted with a painful mass in the left flank region on September 10, 1986. Preoperative diagnosis was hypovascular retroperitoneal tumor in contact with the upper pole of the right kidney. The tumor was removed together with the right kidney on December 18, 1986, and the specimen weighted 640 gm. Histological examination revealed storiform-pleomorphic malignant fibrous histiocytoma. No postoperative adjuvant therapy was carried out. Local recurrence of the disease was found about 9 months after the operation, and the patient died on February 23, 1988. Fifteen cases with MFH arising from the kidney reported in the Japanese literatures are reviewed, and the diagnosis, treatment, prognosis and tumor marker are discussed.

Aged↗
PubMed1990

Chromosome aberration frequencies produced by a 70-MeV proton beam.

The effectiveness of a 70-MeV proton beam in the induction of chromosome aberrations was studied. We employed peripheral lymphocytes and analyzed the frequencies of dicentrics and rings after irradiation at doses ranging from 0.1 to 8.0 Gy at various depths within a Lucite phantom. The frequency of chromosome aberrations after irradiation with an unmodulated proton beam at 5 mm showed a dose-response relationship similar to that of 60Co gamma rays. However, irradiation at greater depths with the spread-out Bragg peak induced higher aberration frequencies at doses lower than those with gamma rays. Furthermore, the distribution curve of chromosome aberration frequencies as a function of depth was found to be slightly different from the physically measured depth-dose curve. With the spread-out Bragg peak the biological effects were more marked at greater depths, resulting in a distribution of relative biological effectiveness values. The results obtained from chromosome aberration analysis may not be related directly to those for the relationship between dose and cell killing. Slight differences in values for relative biological effectiveness due to the change of dose and site of proton beam irradiation may not be important for practical proton beam therapy, but may be important in the prevention of late radiation injuries.

Adult↗
PubMed1990

[A case of infective endocarditis with hemorrhagic fibrinous pericarditis].

A case of infective endocarditis which was complicated with hemorrhagic fibrinous pericarditis was reported. The hemorrhagic fibrinous pericarditis is a rare complication of infective endocarditis of the aortic root and is observed massive hemorrhage into the pericardial space. These patients should be considered for the aortic valve replacement early in the course of the disease.

Aortic Valve↗
PubMed1990

[Radiosensitization of mouse intestinal epithelial cells with BudR].

For the radiosensitization of the repair rich epithelial cells of small intestine, BudR (B.U.) was continuously infused into mice. Its uptake into the DNA, as shown by the substitution rate (S.R.) of thymine to B.U., was dose-dependent in low dose, but above the 4 mg/d/head it did not increased. The radiosensitization effect was assayed by the clonogenecity of the cells, and (1) the repair capacity (recovery factor, RF.) of the cells and (2) the isoeffect dose (I.D) were obtained. From these data, their enhancement ratios (E.R) were estimated. E.R. by R.F. increased remarkably both in low dose and in low S.R., but showed the plateau at about 10 level after 4 mg/d/h of dose or 10% of S.R. Whereas E.R. by I.D. increased linearly in dose or it did quadratically in S.R. From these results, it was discussed that radiosensitization by debromozation of B.U. was seen in low dose, and the direct cytocidal effect of B.U. became dominant with the dose-increase. Also the clinical application of B.U. was discussed in cell kinetical aspect of B.U. labelling as well as the progress of infusion techniques.

Animals↗
PubMed1989

Simple method for determination of A1c-type glycated hemoglobin(s) in rats using high performance liquid chromatography.

We have developed a new chromatographic method for the determination of rat glycated hemoglobins by cation exchange high-performance liquid chromatography. The hemoglobins were eluted by a two-step gradient, and the total assay time, including re-equilibration of the column, was 27 min. Two A1c type and one pre-A1c type rat glycated hemoglobins were separated and measured. The change in major HbA1c of rats, in which diabetes was induced by streptozotocin and which were subsequently treated with insulin, was monitored. In diabetic rats (n = 10, average blood glucose greater than 300 mg/dL), major HbA1c rose to 3.39 +/- 0.06% compared with controls (n = 10, 1.20 +/- 0.03%) during 5 wk. Insulin treatment decreased the HbA1c from 3.48 +/- 0.16% to 2.74 +/- 0.15% (p less than 0.01) in 6 wk. This method was also effective for the determination of mouse HbA1c.

Animals↗
PubMed1989

Associations of health practices and social aspects of life with mortality among elderly people in a Japanese rural area.

A five-year study of persons aged 65 years and over in a Japanese rural area was conducted to examine associations of health practices and the social aspects of life with mortality. Age- and sex-related changes in the associations were examined. For health practices, constipation among men aged 75 years and over, and never or not annually receiving checkups among women aged 75 years and over were associated with increased mortality risk after adjustment for the initial subjective health status. In contrast to no associations between the social aspects of life and mortality among women aged 65-74 years, social aspects of life were more predictive of mortality than subjective health status and health practices among women aged 75 years and over. In this group, having neither a job nor a family role, membership in a group for the elderly while participating only in group tours and/or lecture meetings or without attending any of the regular activities, and infrequent contact with friends were associated with increased mortality. Among men, increased mortality risk was associated with membership in a group for the elderly while participating only in group tours and/or lecture meetings in the 65-74 year-old group.

Aged↗
PubMed1988

Release of inflammatory mediators by noxious stimuli; effect of neurotropin on the release.

Anesthetized rats were perfused with saline in the subcutaneous space of the hind paw and the release of inflammatory mediators induced by noxious stimuli was studied. Not only immunoreactive bradykinin (BK) but also histamine, serotonin (5-HT) and immunoreactive prostaglandin E2 (PGE2) were found to be released into the perfusate when the paw was pinched. Neurotropin, used clinically as an analgesic and anti-allergic drug in Japan, inhibited the release of BK in dose-dependent manner without altering the release of histamine, 5-HT and PGE2. The maximal inhibition of BK release was observed 60 min after p.o. administration of neurotropin. Indomethacin failed to inhibit the release of BK.

Animals↗
PubMed1988

One-electron reduction of hepatic NADH-cytochrome b5 reductase as studied by pulse radiolysis.

The reduction of flavin in hepatic NADH-cytochrome b5 reductase by the hydrated electron (eaq-) was investigated by pulse radiolysis. The eaq- reduced the flavin of NADH-cytochrome b5 reductase to form the red semiquinone between pH 5 and 9. The spectrum of the red semiquinone differs from that of enzyme reduced by dithionite in the presence of NAD+. After the first phase of the reduction, conversion of the red to blue semiquinone was observed at acidic pH. Resulting products are the blue (neutral) or red (anionic) semiquinone or a mixture of the two forms. The pK value for this flavin radical was approximately 6.3. Subsequently, the semiquinone form reacted by dismutation to form the oxidized and the fully reduced forms of the enzyme with a rate constant of 1 x 10(3) M-1 s-1 at pH 7.1. In the presence of NAD+, eaq- reacted with NAD+ to yield NAD(.). Subsequently, NAD. transferred an electron to NAD+-bound oxidized enzyme to form the blue and red semiquinone or mixture of the two forms of the enzyme, where pK value of this flavin radical was approximately 6.3. The blue semiquinone obtained at acidic pH was found to convert to the red semiquinone with a first order rate constant of 90 s-1, where the rates were not affected by pH or the concentration of NAD+. The final product is NAD+-bound red semiquinone of the enzyme.

Animals↗
PubMed1988

Impairment of superoxide release by alveolar macrophage in rats exposed to oxygen and vitamin E.

We examined the digitonin-stimulated release of superoxide by alveolar macrophages (AMs) from young rats exposed to greater than 95% oxygen for 24-168 h. AMS were obtained by lung lavages, and the release of superoxide stimulated by digitonin was measured by using cytochrome C reduction. The total cell count of lung lavages decreased at 24 and 168 h of oxygen exposure (p less than 0.05 for both). The contamination of polymorphonuclear cells (PMNs) was less than 1% up to 120 h of oxygen exposure, and at 168 h PMNs increased to 5% of total cells in lung lavages. The viability of AMs was greater than 95% up to 72 h and then decreased to 90% at 120 h of oxygen exposure and 87% at 168 h. Digitonin-stimulated superoxide release by AMs recovered from lung lavages in rats exposed to hyperoxia showed a slight increase during the first 48 h. However, oxygen exposure for 72 h or more caused a significant decrease of the stimulated superoxide release of AMs compared to AMs from control rats. This decline in stimulated superoxide release of AMs resulting from hyperoxia was not prevented by vitamin E treatment.

Animals↗
PubMed1988

[Bilateral asynchronous renal pelvic tumors: a case report].

A 42-year-old male who had undergone the total nephroureterectomy for transitional cell carcinoma (Grade 3) in the left renal pelvis 5 years ago was seen with asymptomatic macroscopic hematuria. An evaluation of the clinical investigations revealed the right renal pelvic tumor. The right nephroureterectomy was performed and histological examination showed transitional cell carcinoma (Grade 2) of the renal pelvis. Postoperatively, the patient has been treated with intermittent maintenance hemodialysis. He is well and has no evidence of recurrence or metastasis 10 months after the surgery. The previous reports of bilateral renal pelvic tumors (28 cases) are reviewed and the incidence, age, interval between the first and second tumors, prognosis and management including postoperative hemodialysis are discussed.

Adult↗