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Biomedical subjects

H Yamashina

Publications and source records attributed to H Yamashina.

At least 37 records · Page 2Linked to original sources
PubMed1986

[The prophylactic effects of latamoxef against the postoperative infections to open heart surgery. Studies on the penetration of latamoxef into the pericardial fluid and the auricle of heart].

Latamoxef (LMOX, Siomarin) at a dose of 2 g was intravenously administered to each of 23 patients undergoing the open heart surgery and the concentrations in serum, pericardial fluid and auricle of heart were measured. Pharmacokinetic observations are summarized below. The peak serum concentration (t = 0) was 227.3 micrograms/ml and the serum half-life (T1/2 beta) was 1.74 hours. In pericardial fluid, LMOX reached the peak concentration of 28.44 micrograms/ml at 4.9 hours and the half-life was 9.99 hours. In auricle of heart, LMOX reached the peak concentration of 42.78 micrograms/g at 6.9 minutes and the half-life was 1.74 hours. It was shown that LMOX penetrates well into the pericardial fluid and the auricle of heart, and it is considered that their levels exceed the minimal inhibitory concentration against a majority of clinical isolates except Pseudomonas aeruginosa.

Adolescent↗
PubMed1984

[Effect of IV hydration with sodium bicarbonate on high-dose methotrexate disposition kinetics].

Following two-compartment kinetic analysis, the effect of loading of transfusion with sodium bicarbonate on methotrexate disposition was investigated in 13 cases with malignant tumor, being treated with high-dose methotrexate. The mean values of total body clearance, when administered at doses 50 mg and 100 mg per kg body weight, were 0.369 and 0.402 (l/h) per kg, respectively. No significant relationship was observed between alpha value and total amount of transfusion, of urine or dosage of sodium bicarbonate. The other kinetic parameters on elimination, beta value, K10 and total body clearance, did not also correlate with those values described above. These results suggest that the elimination profile of methotrexate show linear kinetics, and that massive administration of transfusion with sodium bicarbonate be not necessary if pH value of urine exceeds 7.0.

Adolescent↗
PubMed1983

Tobramycin inactivation by carbenicillin, ticarcillin, and piperacillin.

The in vitro and in vivo inactivation of tobramycin by carbenicillin, ticarcillin, or piperacillin was investigated by the enzyme immunoassay method in clinically employed dosages. After the addition of an 80-mg dose of tobramycin to 4- to 5-g doses of a penicillin in 100 ml of 0.9% saline or distilled water, the degradation profile of tobramycin appeared to follow a biexponential pattern of decay. Remarkable losses (30 to 40%) of tobramycin combined with carbenicillin or ticarcillin were observed within 1 h, as compared with the later decline. The combination of tobramycin with piperacillin was least inactivating. When the admixture of tobramycin with carbenicillin or piperacillin used in the in vitro study was infused to six volunteers over 1 h, the observed maximum concentrations of tobramycin were on the average 66 and 74% for carbenicillin and piperacillin, respectively, of that observed after tobramycin alone was given. In contrast, the value obtained for tobramycin in combination with piperacillin was close to 90% of the control value. The elimination half-lives of tobramycin combined with the penicillins were slightly shorter than those of tobramycin alone, indicating that the interaction occurs even in patients with normal renal function.

Adult↗
PubMed1983

Pharmacokinetics of a sustained-release theophylline preparation in healthy subjects.

A comparative pharmacokinetic study between a sustained-release theophylline tablet (Theona) and aminophylline powder following multiple oral administrations every 12 h at a 200 mg theophylline dose was performed in ten healthy adult volunteers. As the results, theophylline in Theona revealed almost completely absorbed as is aminophylline. A peak-trough difference with Theona was less than half of that with aminophylline powder. These results suggest that Theona has excellent characteristics as a sustained-release preparation. In addition, in order to investigate dose-dependent kinetics for theophylline, the relationship between average plasma level and dosage was examined with Theona. The plasma level showed proportional change at the low concentrations. When the plasma level was close to 10 micrograms/ml, however, dosage increment results in an increasingly greater change of plasma level, which may indicate a high risk of toxicity.

Adult↗
PubMed1983

[Experimental and clinical studies of cefotiam in thoracic surgery].

The pharmacokinetics of intravenously administered cefotiam (CTM), using a two-compartment or three-compartment open model, have been investigated in patients undergoing thoracic surgery. Patients (Group 1) given 1 hour drip infusion of 1 g of CTM, had the peak serum level (32.8 micrograms/ml) at 1 hour, and the peak pleural effusion level (8.3 micrograms/ml) was achieved at 2.08 hours. Patients (Group 2) given an one-shot intravenous injection of 1 g of CTM, had the maximum pleural effusion concentration (8.35 micrograms/ml) at 2.67 hours. Patients (Group 3) given 1 hour drip infusion of 1 g of CTM, had the mean concentration (2.3--2.5 micrograms/g) in the pleural tissue for 2 to 3.5 hours. Clinical study comprising 20 patients was performed to evaluate the effects of CTM as a prophylactic antimicrobial agent in the thoracic surgery. Patients received intravenous administration of 4 g/day of CTM for 7--10 days. Each patients was evaluated daily for fever, signs of allergic reaction, and wound infection and so on. No infections occurred in these thoracic surgery except 1, and no serious side effects was observed in this study.

Adolescent↗
PubMed1981

A case report of venous aneurysm of the neck vein.

We treated a 37 year old woman with venous aneurysm along left side of the neck. In the beginning, she was asymptomatic and with increase in size of the venous aneurysm she experienced severe pain. Pathohistological examinations revealed a destructive change of the venous wall and thrombosis. Therefore, in cases of venous aneurysm along the neck, such aneurysm should probably be treated surgically to prevent the occurrence of pulmonary embolism.

Adult↗
PubMed1981

Fosfomycin kinetics after intravenous and oral administration to human volunteers.

The pharmacokinetics of fosfomycin, administered intravenously and orally at two different doses (20 and 40 mg/kg of body weight), was studied in seven volunteers. The elimination profile of this antibiotic, when administered intravenously, followed a two-compartment kinetic model, independent of dosage, giving an elimination half-life of 2.23 +/- 0.62 h and an average total volume of distribution at steady state of 0.34 liter/kg. Peak serum levels after rapid intravenous administration of 20 and 40 mg/kg were 132.1 +/- 31.8 and 259.3 +/- 32.5 micrograms/ml, respectively. Peak serum levels after oral administration were 7.1 +/- 1.6 and 9.4 +/- 3.6 micrograms/ml for the 20 and 40 mg/kg doses, respectively. During the first 24 h after administration, an average of 80% of the intravenous doses and less than 25% of the oral doses were recovered in the urine.

Administration, Oral↗
PubMed1981

Permanent pacemaker implantation in patients over 80 years of age.

During the past five years, 150 pacemaker implantations have been done at Hiroshima Prefectural Hospital for the treatment of atrioventricular block, sick sinus syndrome, or slow heartbeat with atrial fibrillation. The patients were divided into two groups by age: the older group of 18 patients over 80 years of age and the younger group of 132 patients under 79 years of age. A comparative study of these two groups was undertaken with respect to pre- and postoperative courses, underlying diseases, cardiac output at variable pacing rate, capture threshold, and prognosis. The older group has as satisfactory a course as the younger group. Seventeen patients out of 18 (94%) in the older group are leading normal productive lives at this writing, and 119 out of 132 (89%) in the younger group are also doing well. In the light of this five-year comparative study, it can be concluded that it is safe and rewarding to implant prosthetic cardiac pacemakers in symptomatic patients over 80 years of age.

Adolescent↗