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Biomedical subjects

M Kitahara

Publications and source records attributed to M Kitahara.

At least 145 records · Page 8Linked to original sources
PubMed1987

Experimental combination chemotherapy of ACNU and 5-FU against cultured glioma model (spheroid) and subcutaneous rat glioma.

The effects of combination chemotherapy of ACNU and 5-FU on cells grown exponentially as monolayers, cells in multi-cell spheroids and in s.c. transplanted tumors of rat glioma clone-6 cells were analyzed by the colony-forming assay. The cytotoxic effect of ACNU on cells in spheroids was enhanced by continuous 5-FU pretreatment for several hours, but further enhancement was obtained only if the 5-FU pretreatment lasted for more than 12 hr. The combined effect was decreased by a drug-free interval due to recovery from potentially lethal 5-FU damage, but ACNU treatment immediately after 5-FU treatment suppressed PLD recovery. Analysis with sequential trypsinization of spheroids indicated that ACNU showed more marked cytotoxicity on cells in the deeper layers in spheroids than on those in the outer layers, whereas the effect of 5-FU decreased towards the deeper cell layers. Enhancement of treatment with ACNU combined with 5-FU was evident for cells in the outer layers, but was more remarkable in the deeper layers. The combined effect of ACNU and 5-FU on s.c. tumors was similar to that in spheroids. The effect of combined treatment of ACNU with 5-FU on increase in body weight was within the additive range of both drugs acting independently, but was more than additive for the growth delay of s.c. tumors.

Animals↗
PubMed1987

Perception of parental acceptance and rejection among Swedish university students.

The Parental Acceptance-Rejection Questionnaire and the Personality Assessment Questionnaire, both developed by R. P. Rohner and his associates, were administered to 71 Swedish university students. The results show significant relations between various forms of parental rejection in childhood and negative personality assessment of the self as an adult, supporting Rohner's parental acceptance-rejection theory. Females showed more dependence and emotional instability than males.

Adult↗
PubMed1987

[Results of combined radiochemotherapy of intracranial ependymoma].

Thirty patients with intracranial ependymoma were treated in our clinic from 1965 through 1984. They were 13 children and 17 adults. As for the location of tumor, 9 were in the lateral ventricle, 8 in the cerebral hemisphere, 12 in the fourth ventricle and one in the third ventricle. Histologically, 18 were benign and 12 were anaplastic. The clinical course was analyzed in 24 cases. Out of the 24 cases, surgical treatment with postoperative radiation therapy was done in 16 cases, surgical treatment with postoperative radiochemotherapy in 6, and radiochemotherapy alone in two. Five-year survival rate of patients treated by surgery with radiation therapy and with radiochemotherapy was 35.7% and 66.7%, respectively. Patients treated by surgery not only with radiation therapy but also with chemotherapy took a better outcome. Recurrence was observed in 9 cases. Four cases of the 9 were benign ependymoma. The recurrence was observed within 3 years after the initial treatment in all cases. Even if histologically benign, the recurrence occurred in a relatively high rate as reported in the past literature. It should, therefore, be stressed that the initial treatment is important not only for a malignant ependymoma but also for a benign one, and the postoperative radiochemotherapy is useful for the improvement of the results.

Adolescent↗
PubMed1987

[Results of supratentorial low-grade astrocytoma--effects of combined radiochemotherapy].

The retrospective analysis of 53 cases with supratentorial low-grade (grade 1 or 2 due to WHO grading) astrocytomas included the years 1965-84. The 5-year and 10-year survival rates were 61.9% and 52.1%, respectively. The recurrence of tumors occurred in 15 cases (28.3%), almost within 3 years after the initial treatment, and early recurrent cases indicated poor results. Among them, 6 cases were noticed increasing malignancy of histological findings. According to our investigations, the factors which influence to the survival rate were age of patients, duration of symptoms before treatment, presence of neurological deficits and degree of surgical removal of tumor. The patients with good prognosis were under 20-year old, over 6 months of duration, with no neurological signs and with total or subtotal removal. But, 5-year survival rate was not so improved by postoperative radiation therapy. Analysis on the effects of chemotherapy for low-grade astrocytoma was little reported. We treated 26 patients with RAFP therapy (Radiation + ACNU + FT-207 + PSK). Only 2 cases out of 26 showed the recurrence till now. The rate of reduction of their tumors was 46.2% by CT scan. So, it was considered that RAFP therapy was effective for supratentorial low-grade astrocytoma.

Adolescent↗
PubMed1987

[Results in oligodendroglioma: postoperative radiotherapy combined with chemotherapy].

The retrospective analysis of 39 cases of supratentorial oligodendroglioma included the years 1965 - 84. The 5-year and 10-year survival rates were 73.1% and 32.2%, respectively. Although oligodendrogliomas were benign tumor, the 10-year survival rate was not good. Recurrence of tumor appeared in 9 cases and some cases were noticed about 10 years after the treatment. So, long term follow-up is important for oligodendrogliomas. Our treatment for oligodendrogliomas was surgical removal and postoperative radiochemotherapy (radiation + ACNU + FT-207 + PSK) for several years. The previous cases who had only subtotal removal of tumor showed short survival time. On the other hand, the cases treated with postoperative radiotherapy or radiochemotherapy showed relatively good results.

Adolescent↗
PubMed1987

Can tinnitus be masked by band erased filtered masker? Masking tinnitus with sounds not covering the tinnitus frequency.

In this study, the effectiveness of masking sound not covering the tinnitus frequency was tested against that of conventional masking sound in 117 subjects. Successful masking was observed in 72% of the former and 70% of the latter. There was no remarkable difference between the two maskers regarding the acceptability and intensity. The duration of residual inhibition, however, was smaller in the masker not covering the tinnitus frequency. The masking sound tested could be useful as an alternative when the conventional one is not accepted.

Adolescent↗
PubMed1987

Endolymphatic sac surgery for Menière's disease: eighteen years' experience with the Kitahara sac operation.

From 1968 to 1983, 162 cases of Meniere's disease were treated surgically with our intramastoid drainage technique. One hundred forty of these cases could be followed up for two years or more. Treatment results were calculated according to the 1972 AAOO criteria and the 1985 AAO-HNS criteria. Using our technique, definitive vertigo spells could be controlled completely in 78% of cases and substantially controlled in 94%. Hearing worsened in only 15% of all cases. Therefore, prevention of worsening of hearing, especially in bilateral cases, and control of vertigo spells in patients with frequent attacks were considered absolute indications for our technique. In this study critical observations were made based on the number of cases hitherto reported by surgeons (the average number of patients undergoing surgery in our clinic was fourteen per year). The need for careful selection of patients for surgery is emphasized.

Adult↗
PubMed1987

Serum osmolality in Menière's disease.

Serum osmolality in patients with Meniere's disease was measured by a Wescore 5100B osmometer to reveal the relationship between a vertiginous attack, the effect of isosorbide, the effect of glycerol, and the osmolality. The following results were obtained: First, the osmotic pressure of the control group ranged from 275 mOsm/kg to 285 mOsm/kg, and that of the Meniere's group ranged from 270 mOsm/kg to 290 mOsm/kg. Both groups showed normal distribution, and mean values of both were 284 mOsm/kg. There was no statistically significant difference between them with regard to serum osmolality. Second, patients with values of 283 mOsm/kg or less were more often in a vertiginous attack period, and patients with values of 284 mOsm/kg or more were more often in an attack-free period. Third, patients with values of 283 mOsm/kg or less were more often in the positive glycerol test group; those with values of 284 mOsm/kg or more were more often in the negative glycerol test group. Finally, there was no significant difference in serum osmolality between patients receiving isosorbide therapy and patients given no treatment.

Glycerol↗
PubMed1987

Induction of experimental endolymphatic hydrops by immunologic techniques.

Immunologic techniques have been used by many investigators to produce experimental endolymphatic hydrops models. These techniques, however, have achieved little success in producing models simulating the idiopathic endolymphatic hydrops of Meniere's disease, in which no inflammatory changes occur in the perilymphatic spaces. In this study, the antigen horseradish peroxidase (HRP) was injected into the endolymphatic sacs of ninety guinea pigs that had been systematically sensitized to this antigen. Endolymphatic hydrops was induced in sixty-seven of the subjects, sixty-four of which showed no inflammatory changes in the perilymphatic spaces. The endolymphatic sacs of the affected guinea pigs were packed with soft granulation tissue induced by immunologic mechanisms; it is felt that the hydrops was caused by disturbances in endolymph absorption resulting from these tissue formations. Our results suggest that the introduction of antigens into the endolymphatic sac may prove useful in producing endolymphatic hydrops with characteristics similar to those occurring in Meniere's disease.

Animals↗
PubMed1986

Combined effect of ACNU and 5-FU on rat glioma cells in spheroids and monolayer cultures.

Combined effects of ACNU and 5-Fu on rat glioma clone-6 cells grown exponentially as monolayers and in multicell spheroids (500-600 micron in diameter) were analyzed by the colony-forming assay. Cells in spheroids with central necroses were more sensitive to ACNU than cells in monolayer, although a large fraction of the cells in these spheroids was resistant to 5-Fu. The effect of ACNU was enhanced by the combined treatment with 5-Fu for cells in both spheroids and monolayers, and was more remarkable when 5-Fu was administered 24 hr prior to ACNU treatment. The enhancement was mainly due to a decrease in the number of spheroid-cells resistant to 5-Fu. Isobologram analysis indicated that the enhancement was supra-additive when a low concentration of 5-Fu was combined with a high concentration of ACNU. It is suggested that a low dose of 5-Fu combined with a high dose of ACNU may preferentially kill more cells in solid tumors.

Animals↗
PubMed1986

Inhibitory effect of prostaglandin E2 on cholesterol ester accumulation in macrophages.

The effects of prostaglandin E2 (PGE2) on the metabolism of beta-migrating very low density lipoprotein (beta-VLDL) in rat peritoneal macrophages were investigated. When cultured in vitro, macrophages apparently incorporated labelled beta-VLDL time-dependently until 12 h, when the incorporation appeared to reach a plateau. Labelled cholesterol ester in the macrophages increased rapidly until 2 h of incubation, did not change from 2 to 6 h, and then increased markedly until 28 h. Labelled free cholesterol in the macrophages increased until 12 h and then decreased until 28 h. Exogenously added PGE2 (10(-7) approximately 10(-5) M) inhibited the accumulation of labelled cholesterol ester between 6h and 28h with or without increasing the level of labelled free cholesterol. These results suggest that PGE2 prevented cholesterol ester accumulation by stimulating either hydrolysis of cholesterol ester or excretion of free cholesterol.

Animals↗
PubMed1986

Enzymatic conversion of 7-hydroxyguanine to its nucleosides.

7-Hydroxyguanine, an antitumor purine-analog, reacted with ribose (or deoxyribose)-1-phosphate in the presence of purine nucleoside phosphorylase. We prepared 7-hydroxyguanine riboside and deoxyriboside using purine nucleoside phosphorylase from bovine spleen. Each nucleoside exhibits antitumor activity against mouse leukemia L1210 cells. The therapeutic effect of 7-hydroxyguanine deoxyriboside is superior to those of 7-hydroxyguanine and 7-hydroxyguanine riboside.

Animals↗
PubMed1986

Suppression of myocardial protein degradation by the protease inhibitor bis[ethyl(2R,3R)-3-[(S)-methyl-1-[4-(2,3,4-tri-methoxy-phenyl-methyl) piperazine-1-ylcarbonyl]butyl-carbonyl]oxiran-2-carboxylat e]sulfate under hypoxia.

The synthetic protease inhibitor bis[ethyl(2R,3R)-3-[(S)-methyl-1-[4-(2,3,4-tri-methoxyphenyl-methyl) piperazine-1-ylcarbonyl]butyl-carbonyl]oxiran-2-carboxylate] sulfate (NCO-700) suppressed both activities of calcium-activated neutral protease and cathepsin B isolated from cardiac muscle, showing 50% inhibition at 46 and 0.8 mumol/l, respectively. A kinetics study using 14C-labelled NCO-700 suggested its incorporation into cultured myocardial cells, demonstrating the half-maximal saturation time at 17 min. Under both aerobic and hypoxic conditions, the reagent inhibited the peptide release from cultured myocardial cells dose-dependently. The amino acid release from heart slices of adult rabbit was also blocked by the drug under hypoxic and glucose-depleted condition. These data and the myocardial infarction size reducing action of NCO-700 might support the view that NCO-700 sensitive protease(s) - possibly, calcium-activated neutral protease and/or cathepsin B - is (are) working to induce an irreversible proteolysis in the process of myocardial cell degradation.

Aerobiosis↗
PubMed1986

[A case showing angiographically moyamoya vessels combined with intracranial calcification].

This case was 36-year-old female with the past history of pulmonary tuberculosis on her 10 years old. During the treatment for pulmonary tuberculosis, transient tetraparesis appeared, and improved completely. She was admitted to our hospital, complaining sensory disturbance of left face and arm on July 25, 1983. Plain skull roentogenogram showed calcification at the base of brain. Computerized tomography (CT scan) showed dilatation of lateral and third ventricles. Cerebral angiograms revealed an occlusion of the right internal carotid artery and the left middle cerebral artery, the stenosis of the basilar artery and bilateral posterior cerebral arteries, transdural anastomosis (so-called vault moyamoya), leptomeningeal anastomosis and moyamoya vessels at the base of brain. Four days after the admission, left hemiplegia appeared suddenly. Because the findings of CT scan and angiogram showed no change, conservative treatment was performed and motor disturbance improved. Biopsy of the calcified mass was carried out and histological findings suggested an old inflammation. Based on the clinical course and examination, it was considered that moyamoya vessels of this case had been formed as a result of tuberculous meningitis. Up to now, only 6 cases with moyamoya vessels at the base of brain coursed by tuberculous meningitis Up to now, only 6 cases with moyamoya vessels at the base of brain coursed by tuberculous meningitis have been reported. In our case, neurological symptoms appeared 26 years after tuberculous meningitis and occlusive changes were seen in bilateral carotid system and vertebrobasilar system.

Adult↗