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Biomedical subjects

Y Kitahara

Publications and source records attributed to Y Kitahara.

At least 91 records · Page 5Linked to original sources
PubMed1987

Comparative study on biological activities of heterocyclic quinones and streptonigrin.

Thirteen heterocyclic quinones (5 quinoline quinones, 7 isoquinoline quinones, 1 indole quinone) were tested for their effects on avian myeloblastosis virus reverse transcriptase, growth of murine lymphoblastoma L5178Y cells, respiration of rat liver mitochondria and oxidation of NADH by Clostridium kluyveri diaphorase in comparison with those of streptonigrin, in which the quinoline quinone moiety is considered to play a crucial role. Most of the quinoline quinones and isoquinoline quinones inhibited reverse transcriptase to the same extent as streptonigrin with the ID50 values ranging between 1 and 5 micrograms/ml, whereas the ID50 value of the indole quinone derivative, 4,7-dihydro-2,3-dimethylindole-4,7-dione, was 80 micrograms/ml. The cytotoxicities of the quinones were much lower than that of streptonigrin; the ID50 values of the quinones were higher than 0.15 micrograms/ml. In particular, the ID50 value of the ortho-quinoline quinone derivative, 8-methoxy-7-methyl-5,6-dihydroquinoline-5,6-dione, was as high as 16 micrograms/ml, while the 50% inhibition of cell growth was seen in the presence of 0.0025 micrograms/ml streptonigrin. The membrane transport of the quinones was evaluated by comparing the effects on oxygen consumption by mitochondria and oxidation of NADH by bacterial diaphorase, being proven not to be responsible for their lower cytotoxicities.

Animals↗
PubMed1987

[Experimental production of mitral valve and papillary muscle lesions by cervical vagus stimulation in rabbits].

Mitral valve and papillary muscle lesions were experimentally produced in rabbits by cervical vagal stimulation or compression of the abdominal aorta. The involvement induced the similar findings to mitral valve prolapse in human beings including mid-systolic clicks and a late systolic or holosystolic murmur. Extrasystoles were also common. Necropsies disclosed papillary muscle swelling, bleeding and edematous change in the mitral valve, swelling of the myocardial cells and interstitial fibrosis. Further, bacterial endocarditis was induced in such rabbits by injecting pseudomonas alkaligenes. Possible connection of experimentally-induced lesions of the mitral complex and mitral valve prolapse in human beings was discussed.

Animals↗
PubMed1987

[Clindamycin-2-phosphate in the treatment of respiratory infections and its distribution into pleural effusion].

We treated pneumonia due to anaerobic bacteria, Mycoplasma pneumonia, and other type of pneumonia with clindamycin-2-phosphate (CLDM-P) and studied the distribution of the drug into pleural effusion. The obtained results are summarized as follows. 1. CLDM-P showed excellent effects in all the treated cases of pneumonia due to anaerobic bacteria and Mycoplasma pneumonia. But the success rate was 50% in cases of other type of pneumonia. We suggest that the drug must be used in due consideration of the types of causative bacteria. 2. Five cases which had developed pleural effusions were treated with intravenous drip of CLDM-P 1,200 mg in 200 ml electrolytic solution to see the distribution into pleural effusions. The results showed that the distribution ratio was 9.0% on the average. Peak levels were 1.86-6.07 micrograms/ml and the concentration was as high as 1.28 micrograms/ml on the average 24 hours after administration.

Adolescent↗
PubMed1986

[Aneurysm of a diverticulum of the ductus arteriosus in an adult: a case report].

An aenurysm of a diverticulum of the ductus arteriosus in a 33-year-old man was presented. The chest radiography revealed a mass obscurring the aortic window above the hilus of the left lung. His blood pressure was 130/70 mmHg, and there was no difference in pressures between the upper and lower or between the right and left extremities. A CT scan of the chest showed 30 X 34 mm angioma adjacent to the descending aorta and pulmonary artery. Aortography and contrast radiography of the right ventricle revealed a cystic pedunculated aneurysm at the superior portion of the descending aorta. The base of the left pulmonary artery was slightly displaced. There was no communication between the aorta and pulmonary artery, nor was any significant difference in pressure between the ascending and descending aorta. This case was diagnosed as an aneurysm of the diverticulum of the ductus arteriosus, and then it was resected. The abnormality was confirmed by the localization of the aneurysm and histopathologic findings, but the presence of the ligamentum arteriosum was not confirmed. This is the 23rd case of the aneurysm of the diverticulum of the ductus arteriosus in adults, and the first case in Japan in which the diagnosis was made in a living patient, followed by successful surgery.

Adult↗
PubMed1986

[Clinical evaluation of cefoperazone in lower respiratory tract infections].

Clinical evaluation and kinetics in serum of cefoperazone (CPZ) in patients with lower respiratory tract infections have been conducted as a multicenter trial participated by 20 institutions in Kyushu area during a period of 8 months from October 1984 to May 1985. Mean serum CPZ levels up to 4 hours following the end of intravenous infusion of either 1 or 2 g CPZ remained higher than the MIC80 of CPZ against major causative organisms of lower respiratory tract infections such as H. influenzae, P. aeruginosa, K. pneumoniae, and S. pneumoniae. Serum half-lives of CPZ following intravenous infusion were prolonged in the elderly and in patients who showed moderate liver or kidney dysfunction, but did not exceed twofold of normal value. Clinical efficacy rates of CPZ were 82.9% (34/41) against pneumonia, 80% (4/5) against lung abscess, 88.9% (32/36) against acute exacerbation of chronic bronchitis, 66.7% (2/3) against panbronchiolitis, 100% (1/1) against acute bronchitis, and 85.7% (12/14), 64.3% (9/14) and 70.0% (7/10) against infections concurrent to chronic respiratory diseases, pulmonary emphysema and bronchiectasis, respectively. The overall efficacy rate was 81.5% (101/124). Bacteriological eradication rates against P. aeruginosa, H. influenzae and S. pneumoniae were 60% (6/10), 88.9% (8/9) and 100% (3/3), respectively. The overall eradication rate including polymicrobial infection was 67.5% (27/40). The clinical efficacy rate of CPZ in patients with underlying diseases such as lung cancer, pulmonary tuberculosis, and pneumoconiosis, etc. was not significantly different from the efficacy rate in patients without these underlying diseases. Of 20 patients who failed to respond to previous antibiotic treatments, 13 were effectively treated by CPZ. Adverse reactions occurred in 6.7% (11/164) of the patients, and consisted primarily of rash, fever, diarrhea and loose stool. Laboratory abnormalities were seen in 5 patients during the study. These included elevations of S-GOT and S-GPT, eosinophilia and neutropenia. CPZ is a very useful drug in the treatment of lower respiratory tract infections because of its excellent clinical efficacy and rare incidence of abnormal accumulations in sera following the recommended 2-4 g/day administration even in the elderly.

Adult↗
PubMed1984

Carrier detection of sialidosis with partial beta-galactosidase deficiency by the assay of lysosomal sialidase in lymphocytes.

Lysosomal and plasma membrane sialidase activities in lymphocytes were studied in four patients with sialidosis with partial beta-galactosidase deficiency, four obligate heterozygotes, and three siblings of a patient. Lysosomal sialidase activity in homozygotes was absent, and that in heterozygotes was significantly decreased to 70% of control level. The results indicate that carriers can be detected by the assay of lysosomal sialidase activity of lymphocytes.

Adult↗