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Biomedical subjects

S Iwata

Publications and source records attributed to S Iwata.

At least 415 records · Page 23Linked to original sources

Radical surgery with myocutaneous flap for advanced penile carcinoma: case report.

A 55-year-old male with penile epidermoid carcinoma of stage C (T3N3N0) underwent radical surgery. Emasculation with profuse skin removal, including the bilateral groins, and inguinal and pelvic lymphadenectomy were performed. A urethrostomy was created at the perineum, and the skin defect was covered with tensor fascia lata myocutaneous skin flaps. Immediately after recovery from surgery, 3 cycles of chemotherapy with cyclophosphamide, adriamycin and CDDP and radiation (5,000 rad) of the local area were given. The patient is now free from tumor recurrence 12 months after the surgery.

Carcinoma, Squamous Cell↗

[Reactor neutron activation analysis for aluminium in the presence of phosphorus and silicon. Contributions of 28Al activities from 31P(n, alpha) 28Al and 28Si(n, p) 28Al reactions].

Reactor neutron activation analysis for aluminium in samples containing phosphorus and silicon was studied. The experiments were performed by using neumatic tube of the Kyoto University Reactor (KUR). At first, the ratios of the 28Al activity produced from 27Al(n, gamma) 28Al reaction by thermal neutrons to that from 31P(n, alpha) 28Al reaction by fast neutrons, and to that from 28Si(n, p) 28Al reaction were measured by gamma-ray spectrometry. With a ratio of about 5 for the thermal to fast neutron flux of KUR, the ratio of the 28Al activity from aluminium to that from phosphorus was to be 812 +/- 7, and to that from silicon 282 +/- 3. Secondly, the contributions of 28Al activities from phosphorus and silicon and the determination limit of aluminium were calculated for various parameters, such as fast neutron flux, thermal to fast neutron flux ratio, amounts of phosphorus and silicon, etc. Thirdly, on the basis of these results, aluminium contents in spinal cords and brains of amyotrophic lateral sclerosis, Parkinsonism-dementia complex and control cases were determined.

Activation Analysis↗

Effect of nigericin on distribution of sodium, potassium and calcium ion in rabbit lens.

Nigericin, a carboxylic monovalent cation ionophore, induced opacification in the rabbit lens within 2 hr of incubation at 37 degrees C at a concentration of 10(-7)M. The opacification was in the subcapsular region where a marked degree of Ca2+ accumulation and change in the monovalent cation balance occurred. Nigericin may accumulate and act locally at the surface region of the lens, presumably due to the high lipid solubility of nigericin. Nigericin induced an opacification of the lens when applied either to the anterior chamber or to the vitreous of rabbit eye.

Animals↗

[Experimental investigation on various administration methods of gentamicin. Comparison of the effect of gentamicin on phagocytosis].

We compared the efficacy of intravenously, intramuscularly administered or intravenously infused over 45 minutes gentamicin (GM) by the experimental system in rabbits using diffusion chambers. Serum concentrations of GM obtained with 3 administration methods were different, while the peak values after intramuscular injection and intravenous drip infusion were similar. Similar concentration time curves of GM in the chambers were revealed after intramuscular injection and intravenous infusion. No marked difference in 3 administration methods was showed in the effects on the growth of P. aeruginosa in the chamber. Viable bacterial number in the chambers decreased when the GM concentration in the chamber was 4--5 times of MIC, and thereafter regrowth was observed after the decrease of GM concentration in the chambers to 2--3 times of MIC. About 8 hours were required for growth to the base line value. In the leucocyte containing chambers, viable bacterial number similarly decreased, but the rate of regrowth was slow. About 12 hours were required for growth to the base line value. The regrowth rate in the GM containing chamber was similar to that in the antibiotic free chamber. From this result, it is suggested that, when the antibiotic concentration in the chamber is 1--2 times of MIC, antibiotic does not show the growth suppressive effect and the activating effect on phagocytosis of leucocytes in the environment closed to the practical pathological condition such as this model. For the patients with qualitative or quantitative abnormal changes of phagocyte, short interval of drug administration might be needed. For this purpose, intravenous drip infusion under monitoring of serum concentration is more suitable than intramuscular injection, which might be accompanied with severe pain and contracture of injected muscle.

Animals↗

[Experimental and clinical evaluation of cefotetan in pediatrics].

Preclinical studies were carried out on cefotetan (CTT), together with clinical studies in the field of pediatrics. The following results were obtained. A total of 114 clinical isolates that have been stored in the authors' department was employed to determine the minimum inhibitory concentrations (MICs) of CTT against various bacterial species. Against E. coli, Salmonella, K. pneumoniae and P. mirabilis, the MICs of CTT showed a peak at 0.78 micrograms/ml, and most of the strains were inhibited by a CTT concentration of 6.25 micrograms/ml or less. The MICs for S. marcescens strains showed a peak at 25 micrograms/ml, with 25% of the strains having MICs of 3.13 micrograms/ml or less, and 67% having MICs of 25 micrograms/ml or more. All of the P. aeruginosa strains had MICs of over 100 micrograms/ml. Against all of the tested strains of S. aureus, a Gram-positive bacterium, CTT showed MICs of 12.5 micrograms/ml or more, while all of the strains of S. faecalis were found to have MICs of over 100 micrograms/ml. CTT was administered intravenously to pediatric patients as a bolus injection, and then the concentration of the antibiotic in the serum was determined as a function of time. When the dosage rate was 10 mg/kg, the mean serum levels were as follows; 58.2 micrograms/ml at 30 minutes, 45.5 micrograms/ml at 1 hour, 33.6 micrograms/ml at 2 hours, 18.0 micrograms/ml at 4 hours and 11.7 micrograms/ml at 6 hours after the injection. The half-life of CTT in the serum at this dosage was thus 2.40 hours. Similarly, at a dosage rate of 20 mg/kg, the mean values at the various times were; 98.6 micrograms/ml at 30 minutes, 75.6 micrograms/ml at 1 hour, 57.8 micrograms/ml at 2 hours, 35.5 micrograms/ml at 4 hours and 23.2 micrograms/ml at 6 hours subsequent to the injection. The half-life of CTT in the serum in these cases was 2.73 hours. CTT was drip-infused intravenously over a period of 1 hour, and then the serum concentration of the drug was monitored with the passage of time. Subsequent to the administration of 10 mg/kg, the mean serum concentrations were as follows; 48.8 micrograms/ml at 30 minutes, 81.5 micrograms/ml at 1 hour, 42.2 micrograms/ml at 2 hours, 23.6 micrograms/ml at 4 hours and 14.8 micrograms/ml at 6 hours subsequent to the injection. The half-life of CTT in the serum after this intravenous drip infusion was thus 2.13 hours.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

[Experimental and clinical studies of an ampicillin suppository (KS-R1) in pediatrics].

Blood levels of ampicillin (ABPC) were measured in 10 childish patients with heart disease after the rectal administration of KS-R1 at doses of 125 mg and 250 mg. Average blood levels of ABPC at 15, 30 minutes, 1, 2 hours and 4 hours after the administration of KS-R1 were 6.8, 6.9, 3.1, 1.1 mcg/ml and 0.1 mcg/ml with half-life of 0.64 hours in patients of age from 1 year to 4 years 7 months old (dose level 8.9 approximately 13.9 mg/kg, average 10.5 mg/kg), and 5.2, 6.1, 3.4, 1.0 mcg/ml and 0.1 mcg/ml with half-life of 0.65 hours in patients of age from 7 years 10 months to 10 years 7 months old (dose level 8.3 approximately 13.9 mg/kg, average 9.8 mg/kg), respectively. Clinical effective rate (excellent and good) was 87% in 55 childish patients with infections. Bacteriologically, 13 strains (74%) out of 18 strains which were isolated from the patients were eradicated. No severe side effects were observed. Diarrhea was observed in 3 cases.

Age Factors↗

[Experimental and clinical evaluation of cefpiramide in pediatrics].

Fundamental and clinical studies on cefpiramide (CPM), a new semisynthetic cephalosporin, were made and the following results were obtained. The antibacterial activities of CPM against clinical isolates were almost similar to those of conventional cephems except for Pseudomonas aeruginosa. The antibacterial activity of CPM against P. aeruginosa was excellent and superior than those of the others. Ten or twenty mg/kg of CPM was given intravenously at one shot to 11 cases. The mean serum levels of CPM reached 231 micrograms/ml at 15 minutes, 119 micrograms/ml at 30 minutes, 88 micrograms/ml at 1 hour, 65 micrograms/ml at 2 hours and 33 micrograms/ml at 6 hours after administration at a single dose of 10 mg/kg, respectively with the half-life of 3.42 hours. In case of 20 mg/kg, the mean serum levels attained 306 micrograms/ml at 15 minutes, 245 micrograms/ml at 30 minutes, 160 micrograms/ml at 1 hour, 118 micrograms/ml at 2 hours and 66 micrograms/ml at 6 hours respectively after administration with the half-life of 5.20 hours. CPM was given intravenously to 12 patients with various bacterial infections. The clinical effects were excellent in 5 cases, good in 6 cases and poor in 1 case and the effective rate was 92%. No side effect was observed in all cases.

Adolescent↗

[Experimental and clinical evaluation of latamoxef in newborn and premature infants].

Latamoxef (LMOX) was used in the treatment and prophylaxis of infections in neonates and immature infants. The following results were obtained. Mean serum concentrations (bioassay) 30 minutes after a single intravenous injection of about 20 mg/kg of LMOX were 49.9 mcg/ml in neonates and 47.3 mcg/ml in immature infants aged 0--3 days, 54.1 mcg/ml in neonates and 60.6 mcg/ml in immature infants aged 4--7 days, 48.9 mcg/ml in neonates and 46.7 mcg/ml in immature infants aged 8--28 days and 62.1 mcg/ml in immature infants aged over 29 days. Six-hour values were 24.1 mcg/ml, 22.5 mcg/ml, 15.9 mcg/ml, 27.2 mcg/ml, 12.9 mcg/ml, 19.1 mcg/ml and 12.8 mcg/ml, respectively. Mean serum concentration half-lives were 6.70 hours in neonates and 8.16 hours in immature infants aged 0--3 days, 3.68 hours in neonates and 5.83 hours in immature infants aged 4--7 days, 3.06 hours in neonates and 4.47 hours in immature infants aged 8--28 days and 2.59 hours in immature infants aged over 29 days. Adequate clinical efficacy can be expected by the intravenous injection of LMOX in doses of 20 mg/kg 1--2 times daily, in neonates and immature infants aged 0--3 days, 20 mg/kg 2--3 times daily, in neonates and immature infants aged 4--7 days and 20 mg/kg 3 times daily, in neonates and immature infants aged 8--28 days. The clinical efficacy of LMOX was good in 5 cases of sepsis (including suspected cases), 5 cases of urinary tract infection, 2 cases of respiratory tract infection and 6 cases of intrauterine infection (including suspected cases). Only a case of respiratory tract infections due to P. aeruginosa was thought to be ineffective. Bleeding tendency was noted in 3 cases, which results from secondary vitamin K deficiency should be checked carefully during the administration of LMOX.

Bacterial Infections↗

Analysis of low molecular weight fractions in human senile cataractous lens.

Previous studies have suggested that changes occur in low molecular weight proteins during the progression of human senile cataract. In this report we have employed the reverse phase mode of high performance liquid chromatography (HPLC) and characterized the patterns of changes in the fractions of low molecular weight substances. Two different types of cataractous lenses, brown and yellow types, were used. Classification of cataract stages in each type was determined by measuring the Na+/K+ ratio in each lens. The profile of low molecular weight substances loosely bound to the reverse phase column changed significantly during cataract progression. In the brown type cataractous lenses, however, the low molecular weight substances changed after the middle stage of cataract progression, while in the yellow type cataractous lenses, the changes started during the early stages of cataract development. These experiments demonstrated that the reverse phase mode of HPLC is a sensitive and specific method for characterization of the quantitative differences in low molecular weight compounds during the progression of human senile cataract.

Aged↗

[Determination of the Ca/P atomic ratio in the spinal cord of patients with amyotrophic lateral sclerosis by neutron activation and X-ray fluorescence analysis].

Ca/P atomic ratios in spinal cords of seven amyotrophic lateral sclerosis (ALS) cases were determined by neutron activation and X-ray fluorescence analyses, and were compared with those of seven control cases. In order to obtain calibration curves, the standard samples with 0.01-0.1 of Ca/P atomic ratio were prepared by mixing diammonium hydrogen phosphate with calcium carbonate. In neutron activation analysis, gamma-ray spectra of 49Ca and beta-ray intensities of 32P produced from (n, gamma) reactions of the spinal cords and standard samples were measured by Ge(Li) and GM detectors, respectively. In X-ray fluorescence analysis, the samples were excited with 1.6 MeV alpha particle beam accelerated by a Van de Graaff accelerator, manganese K X-rays from 55Fe radioactive source and rhodium K alpha X-rays from X-ray tube, respectively. The characteristic X-ray spectra were measured by Si(Li) or proportional detector. From the peak areas on the spectra and beta-ray intensities, the Ca/P atomic ratios in spinal cords were determined. Based on these results, the Ca/P atomic ratio of precipitate including calcium and phosphorus in spinal cord of ALS case was calculated. As a result, the Ca/P atomic ratios in spinal cords of ALS and control cases were 0.018-0.021 and 0.030-0.049, respectively. The calculated Ca/P atomic ratio in the precipitate of ALS case was estimated to be 1.6.

Amyotrophic Lateral Sclerosis↗

[Pharmacokinetics study on gentamicin intravenous drip infusion in children].

Pharmacokinetics of gentamicin in children after intravenous infusion over 60 minutes were compared with that after intramuscular injection. 1. Mean measured peak serum levels after intravenous infusion of 2.5 mg/kg and intramuscular injection of 2.0 mg/kg were 6.1 micrograms/ml at termination of infusion and 6.5 micrograms/ml at 30 or 60 minutes after injection, respectively. Older children showed higher serum levels. 2. There was no difference in serum half-life between both modes of administration. 3. The AUC after intravenous infusion was slightly larger than that after intramuscular injection. 4. It was suggested that the efficacy and safety of the treatment by intravenous infusion in children are comparable to that by the intramuscular injection, and optimum single dose is 1.5--2.5 mg/kg.

Adolescent↗

[Determination of Ca/P atomic ratio in calcium-hydroxyapatite by neutron activation analysis].

The Ca/P atomic ratios of synthesized calcium-hydroxyapatite (Ca10(PO4)6(OH2) were determined by neutron activation analysis. In order to obtain calibration curves, the standard samples, such as calcium monohydrogenphosphate, calcium dihydrogenphosphate, etc., were prepared. gamma and beta ray spectra, and beta ray intensities of calcium-hydroxyapatite and standard samples irradiated with reactor neutrons were measured by using a Ge(Li) detector, a low background beta ray spectrometer and GM detector. Based on these results, deviation coefficient of the calibration curve, accuracy of the Ca/P atomic ratio, minimum determination limit, etc. were compared in detail. From the present analysis, the Ca/P atomic ratio of calcium-hydroxyapatite was able to obtain with the standard deviation of about 2% for 1 mg sample.

Activation Analysis↗

Nine cases with postintubation granuloma of the larynx.

Nine cases with postintubation granuloma of the larynx were observed during the last 7 years at our infirmary. The age ranged from 30 to 58 years, the average being 45 years. Seven were females and two were males. Granuloma of the larynx was found in the posterior one thirds of the vocal cord in eight cases out of the nine. Surgical removal of granulomas was performed in eight cases under laryngomicrosurgery, whereas other one case responded to conservative treatment.

Adult↗