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Biomedical subjects

M Okamoto

Publications and source records attributed to M Okamoto.

At least 559 records · Page 31Linked to original sources
PubMed1994

[Annual sperm concentration variation in semen collected by electroejaculation in the cynomolgus monkey (Macaca fascicularis)].

To observe annual sperm concentration variations in the cynomolgus monkey, semen samples from four cynomolgus monkeys were individually collected by the rectal probe electroejaculation technique every two weeks throughout an experimental period of two to three years. The annual variation in mean values of semen volume and sperm concentration in each animal examined were expressed as 0.10 to 0.16 ml and 154.54 to 267.17 x 10(6) sperm/ml of semen, respectively. The annual sperm concentration variation in samples collected from each animal was between 10(7) and 10(9) sperm/ml of semen. It was observed that the percentage of active spermatozoa ranged from 60 to 80 per cent, and correlated with both the sperm concentration and the semen volume. These results suggest that annual variation in sperm concentrations of semen collected by electroejaculation is due to differences in the contraction of muscles adjacent to the accessory genital gland and ampulla elicited by electrical stimulation.

Animals↗
PubMed1994

[Pathogenesis of spontaneous nephrosis in mice--urinary protein in nephrotic mice].

There is a paucity of model animals for naturally occurring nephrosis. The nephrotic mouse strain (ICGN) found from ICR mouse colony at National Institute of Health could be one of the most suitable model for nephrosis. We maintained the strain of mice which was originated from the hybrid between the nephrotic ICGN mice and ICR mice. Nephrosis is diagnosed with the presence of albumin band on SDS-PAGE of the urine. The detection of urinary albumin using SDS-PAGE could be valuable for early diagnosis of nephrosis in the mice. The total urinary protein concentration was determined on the course of nephrosis. The nephrotic mice showed slightly higher protein concentration between 2 and 6 days old as compared to control mice. Until 16 day old, it was maintained relatively low level. Thereafter, the total urinary protein increased gradually. However the diagnosis of nephrosis with total urinary protein alone may be limited due to the major urinary protein which can be detected even in normal rodents.

Albuminuria↗
PubMed1994

Polymorphic ventricular tachycardia with cardiac sarcoidosis: treatment with low-dose metoprolol and cibenzoline.

A 38-year-old female had felt exertional dyspnea for six months. Physical examination and laboratory data including angiotensin-converting enzyme, failed to diagnose sarcoidosis. Her chest X-ray showed cardiomegaly but no hilar lymph node enlargement. Holter ECG showed nonsustained and sustained ventricular tachycardias, monomorphic or polymorphic tachycardia. Echocardiography and contrast left ventriculography showed left ventricular dilatation and generalized hypo- and akinesis. Endomyocardial biopsy revealed myocardial sarcoidosis. Administration of corticosteroids, metoprolol of 20 mg/day and cibenzoline of 300 mg/day was markedly effective for the treatment of ventricular tachycardia. This patient is alive for one year after treatment and the combination therapy seems to contribute to good prognosis.

Adult↗
PubMed1994

Investigation of pure-tone hearing levels at a single frequency in sudden deafness.

Hearing levels in patients with sudden deafness are commonly discussed in terms of average thresholds at 3 or 5 frequencies, but an investigation of hearing levels at a single frequency is also important. In this paper, pure tone thresholds at 500 Hz and 4,000 Hz were investigated in patients with sudden deafness who came to our clinic within 4 days of onset. Particular attention was paid to the relationship between audiometric types according to the contour of the initial loss and degree of hearing recovery at each frequency. In the group of patients whose initial hearing level at 500 Hz was between 55 and 70 dB, the hearing recovery at 500 Hz in the upward slope type was significantly greater than that in the downward slope type, but in other groups no significant differences in hearing recovery were observed among the different types of initial audiograms. We considered that the hearing recovery at a single frequency was not related to the audiometric type except in the patients with the upward slope type with moderate hearing loss.

Adolescent↗
PubMed1994

Sudden deafness accompanied by asymptomatic mumps.

In this study we investigated asymptomatic mumps as a possible cause of sudden deafness. We studied 131 sudden deafness patients by measuring their serum mumps antibody values. Positive IgM antibody results, which strongly suggest recent mumps infection, were revealed in 9 of the 130 patients tested (6.9%). Asymptomatic mumps infections are apparently closely related to sudden deafness. Further studies will provide more definite diagnoses of mumps deafness and might be applicable to the treatment of such hearing loss.

Adolescent↗
PubMed1994

Study on the distribution of hearing levels in idiopathic bilateral sensorineural hearing loss.

The pattern of aggravation in hearing was investigated in 105 patients who were diagnosed as having idiopathic bilateral sensorineural hearing loss at the Hearing Loss Clinic, Department of Otolaryngology, Kitasato University Hospital. Audiograms were taken 1,069 times from the 105 cases over more than 3 years, and were used to obtain the distribution of hearing levels at each test frequency. The clinical course of idiopathic bilateral sensorineural hearing loss was divided into three stages: Stages I, II and III, based on the pattern of aggravation. The pattern of distribution of hearing levels at different stages was compared with each other with reference to peaks or clustering points. Similar peaks were noted at Stage II and Stage III as aggravation proceeded from Stage I. Another peak was noted in the zone of scale-out.

Adolescent↗
PubMed1994

Transient deafness with iopamidol following angiography.

A case of transient, severe sensorineural hearing loss with iopamidol following angiography is reported. The 26-year-old woman had previously been diagnosed with Arnold-Chiari malformation, and underwent vertebral angiography by a retrograde transfemoral catheterization. Immediately following the second injection of iopamidol she did not react on the nurse's call. An ABR revealed no response in either ear even when the click intensity was 105 dB. The patient was immediately treated with steroid and OHP. Fortunately, 24 h after the angiography she was able to communicate at a normal conversation level. Transient severe sensorineural hearing loss is thought to result from bilateral anoxia of the cochlea due to hypoplasia of the basilo-vertebral artery systems. Cochlea anoxia lasts 10-20 min after which the hearing loss is recovered.

Adult↗
PubMed1994

FR901451, a novel inhibitor of human leukocyte elastase from Flexibacter sp. I. Producing organism, fermentation, isolation, physico-chemical and biological properties.

A novel human leukocyte elastase (HLE) inhibitor, FR901451 was discovered in the fermentation broth of a bacteria. The bacteria was identified as Flexibacter sp. No. 758. FR901451 has a molecular weight of 1269 and a molecular formula of C60H79N13O18. The mode of inhibition against HLE is competitive, with a Ki value of 9.8 x 10(-9) M.

Animals↗
PubMed1994

FR901451, a novel inhibitor of human leukocyte elastase from Flexibacter sp. II. Pharmacological effect of FR901451.

Intratracheal (i.t.) or intravenous (i.v.) administration of FR901451, a potent inhibitor of human leukocyte elastase (HLE) prevented HLE-induced lung hemorrhage in hamsters with ED50 values of 10.5 micrograms/site and 8.1 mg/kg, respectively. alpha 1-Antitrypsin (alpha 1-AT) also showed inhibitory effect in this model. However, the ED50 value by i.t. injection of FR901451 was 20-fold lower than that of alpha 1-AT. Moreover, FR901451 i.t. significantly modulated porcine pancreas elastase (PPE)-induced changes of the respiratory mechanics in hamsters. The ED50 values were 529 micrograms/site and 244 micrograms/site, which were expressed by static lung compliance (Cst) and vital capacity (VC) of the lungs, respectively. These results suggest that FR901451 could be clinically useful agent for the treatment of the destructive lung disease such as pulmonary emphysema.

Animals↗
PubMed1994

[CAMBO-VIP for advanced diffuse large cell lymphoma (LSG classification)--a long-term follow-up study].

Twenty-two patients with advanced diffuse large cell lymphoma (LSG classification) were treated with the combination chemotherapy of cyclophosphamide, doxorubicin, methotrexate with leucovorin rescue, bleomycin, vincristine, etoposide, ifosfamide and prednisolone (CAMBO-VIP) from Oct. 1987 to Sept. 1989. Eighteen (90%) of 20 evaluable patients achieved complete remission and 2 patients had partial remission. With a median follow-up of 52 mos, 3 patients relapsed (17%), and 2 patients died. The actuarial overall survival and relapse-free survival at 4 years were estimated to be 90% and 83%, respectively. Myelosuppression was severe, but transient. No serious infection was seen, and no platelet transfusion was required. Oral mucositis and liver damage (Grade 3 in WHO grading) was seen in one patient each, but no treatment-related fatalities were observed. CAMBO-VIP is a well tolerated, effective treatment regimen for advanced diffuse large cell lymphoma.

Adolescent↗
PubMed1994

[Increased blood cell destruction during vigorous regeneration of bone marrow after CAMBO-VIP chemotherapy for non-Hodgkin's lymphoma].

Alternating non-cross-resistant chemotherapy has been induced for the treatment of non-Hodgkin's lymphoma (NHL) with the aim of cure, even in advanced cases. We formulated a new high dose regimen, CAMBO-VIP, which was a weekly treatment. They were administered during alternate weeks for a total period of 12 weeks. We obtained high response rate and prolonged disease-free survival with this regimen. We noticed the elevation of serum LDH level in some patients at or shortly after the completion of CAMBO-VIP treatment. LDH elevation was not associated with liver function abnormality in terms of elevation of GOT or total bilirubin. All of these patients were in complete or partial response with no evidence of tumor progression. An LDH isozyme study which was done at the time of LDH elevation showed elevation of both LDH1 and LDH2. Interestingly serum haptoglobin was undetectable in all 6 patients measured at the time of LDH elevation. Reticulocytosis and leukoerythroblastosis in peripheral blood were also observed in all of these patients. These abnormalities including LDH elevation returned to normal within a rather short period, usually within 1 to 3 weeks. From these observations, it is most likely that these abnormalities were due to excessive blood cell destruction, which was observed in association with rapid recovery from myelosuppression.

Adolescent↗
PubMed1994

[Pharmacokinetics of paclitaxel in experimental animals. Part 1. Blood level].

The plasma disposition of paclitaxel in rabbits (7 mg/kg, 1 h i.v. inf.) was biphasic with half-lives of 0.36 and 6.36 h, and AUC was 9.46 micrograms.hr/ml. K12 value was larger than K21 and V2 was larger than V1, suggesting that paclitaxel had a favorable distribution profile in tissues. In S 180 bearing male ICR mice (30 mg/kg, i.v. bolus), the biphasic plasma disposition was also observed. The half-lives and AUC were 0.25 h, 2.23 h and 117.93 micrograms.hr/ml. Paclitaxel distributed widely in plasma rather than blood cells. The biliary level of paclitaxel in the enlarged gallbladder of ICR mice was markedly high, about 10-fold higher than the urinary level and 100-fold higher than the plasma level. The bioavailability with oral administration to ICR mice was poor. AUC(oral)/AUC(i.v.) ratio in the bile, liver, tumor and plasma was 18.91, 6.71, 0.83 and 0.45%, respectively.

Administration, Oral↗
PubMed1994

[Pharmacokinetics of paclitaxel in experimental animals. Part 2. Tissue distribution].

In S 180 bearing male mice, paclitaxel was rapidly distributed to various tissues within 10 minutes. The highest AUC was seen in the liver, and relatively high in the pancreas, kidney, thymus, intestine, stomach and lung. The concentration of paclitaxel in tumor tissue was not so high early time after administration, but was sustained for a long time with a half life of 12.3 hr. Elimination from the testis and thymus was also slow. The drug level in the brain was very low. In M 109 bearing female CDF1 mice, the distribution and elimination profile of paclitaxel was comparable to that in S 180 mice. The concentration of paclitaxel in the ovary, lung and uterus decreased slowly. In M 109 tumor, which was very sensitive to paclitaxel, the drug had a higher and long lasting distribution compared with S 180 tumor. In S 180 tumor bearing mice pretreated with CCl4, the paclitaxel level was found to be lower in the liver and higher in the other tissues including tumor, plasma, urine and bile than in non-treated mice.

Animals↗