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Biomedical subjects

K Tamate

Publications and source records attributed to K Tamate.

At least 37 records · Page 2Linked to original sources
PubMed1992

[Role of oxygen radical and superoxide dismutase in ovulation in the rat].

We studied the effect of Cu,Zn-superoxide dismutase (SOD) and Mn-SOD, which are specific scavenging enzymes of the superoxide anion radical, on ovulation and examined the localization of SOD in rat ovaries. The results were as follows. 1) The number of ova in the Cu,Zn-SOD (8 mg x 4) administrated group (27.8 +/- 5.4 : p less than 0.01) was significantly reduced compared to the control group (49.0 +/- 3.3). Similarly, the number of ova in the Mn-SOD (2 mg x 2) administrated group (16.9 +/- 7.6 : p less than 0.01) was significantly reduced compared to the control (52.9 +/- 6.3). 2) In the rat ovary, Cu,Zn-SOD examined by the immunohistological method was found to be localized in the granulosa cells of mature Graafian follicles, growing follicles, primordial follicles and epithelial cells of the fallopian tubes. Mn-SOD was localized in the external theca cells of mature Graafian follicles and the corpus luteum. The activity of SOD estimated by the modified nitroblue tetrazolium method was consistent with the immunohistological localization of both SODs. We considered that oxygen radicals and SODs play an important role in rat ovulation, and Cu,ZN-SOD and Mn-SOD have a different localization and action in the rat ovary.

Animals↗
PubMed1991

[Study on flomoxef in the perinatal period].

The placental passage and the the therapeutic efficacy of flomoxef (FMOX, 6315-S) were studied in patients in the perinatal period. A summary of the obtained results is as follows: 1. Concentrations of FMOX in maternal serum, umbilical cord serum and amniotic fluid obtained upon one-shot intravenous injections to 12 patients were compared with those obtained upon 1 hour drip infusions to 9 patients. It was found that the former means of administration gave higher concentrations that the latter. 2. Concentrations of FMOX in maternal serum, umbilical cord serum and amniotic fluid at 1 to 6 hours after administration through either method were all higher than MIC80's of recognized bacteria. 3. Clinical efficacies were evaluated in 10 patients with puerperal intrauterine infection, 7 patients with endometritis, 2 patients with pyelonephritis and 1 patient each with endo-cervicitis, amniotic fluid infection, mastitis and perineal wound infection. Clinical efficacies were excellent in 5 patients (21.7%), good in 17 patients (73.9%) and poor in 1 patient (4.4%), thus the overall efficacy rate was 95.7%. 4. Eradication of causative bacteria were obtained in all 8 cases tested, hence the eradication rate was 100%. 5. Mild diarrhea in 1 patient was the only side effect observed. No abnormal clinical laboratory test results were found in any patients.

Adult↗
PubMed1991

[Transvaginal ultrasonographic findings and hCG levels in early intrauterine pregnancies].

The correlation of transvaginal ultrasound (TVU) findings with serial hCG determinations was evaluated during early pregnancy in 60 patients. In these patients, the time of ovulation was accurately determined by ultrasonic monitoring of follicular rupture. The results were as follows. 1) A gestational sac less than 6 mm in diameter was identified in 22 of 38 cases (57.9%) in 4 weeks gestation, and the mean number of cycle days for detection of the GS was 34.1 +/- 2.5. On the other hand, fetal heart movement was detected as early as 43.0 +/- 2.8 days from the last menstrual period. 2) A good linear relationship was found between the gestational age and size of the gestational sac and size of the fetus. 3) A gestational sac was identified in one of 10 cases (10.0%) with hCG levels below 1,000 mIU/ml (1st IRP), 5 of 6 with levels of 1,000-2,000 mIU/ml, and all 15 cases with levels above 2,000 mIU/ml. These results suggested that TVU could significantly improve the detection of gestational sacs, and result in a lower hCG threshold than previously established with transabdominal sonography. Furthermore, our findings derived from patients in which the date of ovulation could be accurately determined by ultrasound should be useful in further studies of early fetal development.

Chorionic Gonadotropin↗
PubMed1990

Production of 3-N-[11C]methylspiperone with high specific activity and high radiochemical purity for PET studies: suppression of its radiolysis.

3-N-[11C]methylspiperone(11C-NMS, molecular weight = 409 for 12C-NMS) has been prepared automatically with high specific activity (37 +/- 18 GBq/mumol at EOS) for the measurement of dopamine D2 receptors in the human brain with a positron camera. It was observed that the radiochemical purity of 11C-NMS decreased from 97.8% (in HPLC eluate) to 83.5% (in saline, after the dispensing procedure, at 29 min from EOS), and to 79.9% in a further 59 min and that another 11C-labelled compound with a molecular weight of 425 (as a 12C-labelled compound) was formed. It was also observed that an aqueous solution of carrier methylspiperone (NMS) decomposed on 60Co irradiation and, using the same analytical conditions, gave the compound with the same retention time and the same molecular weight as 11C-NMS gave. The G-value of NMS decomposition by 60Co irradiation was estimated to be about two in an aqueous solution. The decomposition of 11C-NMS was suppressed remarkably by the addition of hydroxyl radical scavengers such as potassium iodide, and accelerated slightly by a hydrated electron scavenger such as sodium nitrate. Therefore, it was assumed that the hydroxyl radical generated by the radiolysis of water played an important role in the decomposition of 11C-NMS in the aqueous solution. Polysolvate-80 and ethyl alcohol were used as i.v. injectable additives to protect 11C-NMS against decomposition. In 47 routine productions, 2.7 +/- 1.7 GBq of 11C-NMS aqueous solutions ready for i.v. injection have been produced at 98.3 +/- 1.0% radiochemical purity using an automated synthesis apparatus. The products were used for clinical purposes with a positron camera and animal experiments.

Brain↗
PubMed1985

Computer-controlled large scale production of high specific activity [11C]RO 15-1788 for PET studies of benzodiazepine receptors.

Ethyl 8-fluoro-5,6-dihydro-5-[11C]methyl-6-oxo-4H-imidazo [1,5-a] [1,4]benzodiazepine-3-carboxylate ([11C]RO 15-1788) has been prepared automatically with high specific activity for in vivo visualization or quantitative analysis of brain benzodiazepine receptors. The yield, radiochemical yield, radiochemical purity and specific activity of the product ready for an i.v. injection were 276 +/- 76 mCi, 50.8 +/- 7.8%, 99.3 +/- 0.3% and 2.9 +/- 0.5 Ci/mumol, respectively, taking an average of the latest 3 runs. The time required was about 25 min. Each product was sufficient to carry out three successive clinical studies by positron emission tomography (PET). All the procedures other than evaporation and filtration at the final stage were carried out with specially designed equipment connected to a central control system for radioisotope production.

Anticonvulsants↗
PubMed1982

Aspects of the preparation of 18F-2-deoxy-2-fluoro-D-glucose (18FDG) for medical use.

Fluorine-18-2-deoxy-2-fluoro-D-glucose (18FDG) for medical use had been prepared with the attention regarding radiochemical yield and purity, specific activity and quality control. More than four 18F-by-products in 18F-adducts from the reaction of triacetyl glucal with 18F2 were detected by the autoradiography of thin layer plates in which two by-products could not be perfectly removed by a column chromatography, and selective collection of the eluate gave 18FDG with the purity of 96.7% as an average in 12 runs. At end of synthesis (EOS) 259-925 MB (7-25 mCi) of a sterilized, isotonic solution of 18FDG was obtained with the specific activity of 629-851 MBq (17-23 mCi)/mg at end of bombardment (EOB) after preparation time of 3-3.5 hr, in which bacteria and pyrogen were not detected.

Chromatography↗
PubMed1982

Convenient 77Kr production method for medical use.

A convenient method of 77Kr production has been developed for its routine medical use in cerebral blood flow measurement. An aqueous solution of NaBr (40 wt%) was used as the target and 77Kr produced by the 79Br(p, 3n)77Kr reaction was rapidly recovered from the target under a He stream. The optimal target thickness was determined to be 5 approximately 6 mm by investigating radionuclidic purity and proton current effect on the yield. About 740 MBq (20 mCi) of 77Kr with a radionuclidic purity of 92% was obtained within 5 min after a 5 microA-20 min irradiation. The present method has been demonstrated to be suitable for routine 77Kr production.

Cerebrovascular Circulation↗
PubMed1978

[Simple method for producing 13NN and 15OO by proton bombardment of aqueous phase (author's transl)].

A simple method has been developed for the production of 13NN and 15OO by proton irradiation of aqueous solutions. 90 mCi of 13NN was obtained in a 200 ml. of He by using 1.0M NH4CI solution at pH 11 as the target with 10 min irradiation of 15 MeV, 10 microamperemeter protons. 80 mCi/min of 15OO was continuously obtained in a 200 ml of O2 by using pure water as the target with 40 MeV, 2 microamperemeter protons. The radiochemical purity of these short-lived radioactive gases obtained by this method was greater than 99.9% by passing through a single absorber.

Ammonium Chloride↗
PubMed1978

[Caffeine-11C, ephedrine-11C and methylephedrine-11C: Synthesis and distribution in mice (author's transl)].

Caffeine, ephedrine and methylephedrine were labeled with carbon-11 by the action of methyliodide-11C on theophylline, norephedrine and ephedrine, respectively. Caffeine-11C was prepared in 44 min with a radiochemical yield of 40%, ephedrine-11C in 45 min with a 11% radiochemical yield and methylephedrine-11C in 36 min with a 43% radiochemical yield. When injected in mice intravenously, these products show a high uptake in the liver, the kidney and the blood for caffeine-11C and in the liver and the kidney for ephedrine-11C and methylephedrine-11C. The brain uptake for these products was found to be 2.4 to 3.9% of the injected dose per gram at 5 min after injection. These studies in mice have demonstrated that these products are potentially useful agents for the dynamic studies of the brain.

Animals↗
PubMed1977

[Remote system for the mass production of short-lived radioisotopes in a cyclotron. Development of the system and radioisotope production].

A system was developed for producing short-lived radioactive substances (11CO, 11CO2, 13NN, 13NH3, 18F-, 62Zn2+, 123I-, etc.) on a scale enough for clinical use, which could also be used for analyzing them rapidly and for investigating their production methods, with less received dose by workers. The system enabled us to produce remotely several tens mCi of of short-lived radioactive susbtances readily usable for clinical diagnosis, continuosly for radioactive gases, 11CO, 11CO2 and 13NN, or repeatedly at short intervals for radioactive aqueous solutions of 13NH3, 18F-, etc. Employing this system, the average received dose per month was reduced considerably.

Carbon Radioisotopes↗