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Biomedical subjects

T Hirata

Publications and source records attributed to T Hirata.

At least 397 records · Page 22Linked to original sources
PubMed1988

Structures and actions of Mytilus inhibitory peptides.

Two congeneric peptides that inhibit contraction of the anterior byssus retractor muscle of Mytilus edulis were isolated from the pedal ganglia of the mussel. Their structures were determined to be H-Gly-Ser-Pro-Met-Phe-Val-NH2 and H-Gly-Ala-Pro-Met-Phe-Val-NH2. These hexapeptides also showed inhibitory action on contractions in several other molluscan muscles, such as the cardiac muscle of Meretrix lusoria and the penis retractor muscle of Achatina fulica.

Amino Acid Sequence↗
PubMed1988

Morphological changes in Mycobacterium fortuitum induced by ofloxacin.

Effects of ofloxacin on morphology of Mycobacterium fortuitum ATCC 6841 were studied electronmicroscopically. The cells treated with 0.2 microgram/ml (1/2 MICs) of ofloxacin at 37 degrees C for 24 h maintained normal morphology under scanning electron microscopic observations. In the ultrathin sections of the cells treated with ofloxacin under the same conditions, ribosomal granules and other cytoplasmic organellae were clearly observed, whereas the fine fibrous structures of the nuclear apparatus were not clear. On the other hand, the treatment with 0.2 microgram/ml of ofloxacin at 37 degrees C for 5 days caused elongation of the cells, and irregular, rosary-like and/or twisted features in some cells under scanning electron microscopic observations. The formation of numerous vacuole-like structures in the cytoplasm, the indistinct nuclear apparatus, and the partial destruction of the cell wall were observed in the transmission electron microscopic examinations. We conclude from this study that morphological changes in Mycobacterium fortuitum cells treated with ofloxacin seem to firstly occur in the nuclear apparatus.

Anti-Bacterial Agents↗
PubMed1988

Evaluation of rapid drying hand disinfectant preparations in the intensive care unit.

MK412A (0.2% chlorhexidine in 70% ethanol) and MK412B (0.2% benzalkonium chloride in 70% ethanol), which are rapid drying and rubbing antiseptic preparations, have been evaluated for hand sterilization over a month by ICU nurses. They have been shown to have effective skin decontaminant efficacy under practical conditions in a busy ICU. There were no adverse reactions except for two cases of mild erythema in the MK412A treatment group. In a comparative in vitro study with Pseudomonas cepacia, 0.2% chlorhexidine solution alone and 0.2% benzalkonium chloride solution alone were less bactericidal than MK412A and MK412B.

Benzalkonium Compounds↗
PubMed1988

Primary intracranial germ-cell tumors. A retrospective analysis with special reference to long-term results of treatment and the behavior of rare types of tumors.

Thirty cases of primary intracranial germ-cell tumors were reviewed with reference to the effect of treatment. Histologically, there were 23 pure germinomas, while the remaining tumors had more unusual histology; 3 of these were teratomas, and 4 germ-cell tumors with the admixture of yolk sac tumor (YST) or embryonal carcinoma (EMC). Three of these rare cases are presented. The performed surgery and radiotherapy, seemed adequate for pure germinomas, and all these cases lived tumor-free after an observation time of 13 to 139 months although 4 patients developed intellectual retardation or cerebral dullness after radiotherapy. Four cases with YST and EMC elements, indicated by the elevation of AFP and HCG values in serum, were resistant to radio- and chemotherapy and developed, despite surgically total removal of the tumor, intra- or extracranial metastases. A review of the literature is included.

Adolescent↗
PubMed1988

Placental alkaline phosphatase as a tumor marker for primary intracranial germinoma.

A sensitive enzyme-linked immunosorbent assay (ELISA) was used in a retrospective study of placental alkaline phosphatase (PLAP) levels in serum, cerebrospinal fluid (CSF), and intratumoral cyst fluid in primary intracranial germinoma. The ELISA showed no cross-reactivity with intestinal alkaline phosphatase except in very high concentrations, after samples had been heat-treated. Three patients with germinoma were studied for serum PLAP levels and in all the levels were elevated (3.78, 0.52, and 2.11 IU/liter). Two of the germinoma patients were studied for PLAP levels in the CSF, and both had elevated levels (0.83 and 9.83 IU/liter). The intratumoral cyst fluid in one case of germinoma was tested for PLAP and the level was found to be very high (603 IU/liter). These PLAP levels decreased concomitantly with the reduction in tumor size during irradiation. Serum PLAP levels were measured in 40 control adult male individuals and in the CSF of 20 nonpregnant patients with subarachnoid hemorrhage. The upper normal limits were 0.20 and 0.11 IU/liter in the serum and the CSF, respectively. All PLAP levels measured in the serum of patients with various brain tumors were 0.18 IU/liter or less. This study strongly suggests that PLAP is a clinically useful tumor marker for primary intracranial germinoma.

Adolescent↗
PubMed1988

Carbazomycins G and H, novel carbazomycin-congeners containing a quinol moiety.

Carbazomycins G (I) and H (II), new congeners of the carbazomycin complex, have been isolated from the culture broth of Streptoverticillium ehimense. They have proved to contain a unique quinol moiety in the molecule. Their structures have been elucidated by mass and NMR spectrometries and X-ray crystallographic analysis. Carbazomycin G showed moderate antifungal activity against Trichophyton species.

Anti-Bacterial Agents↗
PubMed1987

Catch-relaxing peptide isolated from Mytilus pedal ganglia.

A peptide that relaxes catch tension of the anterior byssus retractor muscle of Mytilus edulis was purified from pedal ganglion extracts of the mussel. Its primary structure was determined to be H-Ala-Met-Pro-Met-Leu-Arg-Leu-NH2. This peptide was found to have not only catch-relaxing action on the byssus retractor muscle but also modulatory actions on contractions in various molluscan muscles.

Animals↗
PubMed1987

Asystole with syncope following strenuous exercise in a man without organic heart disease.

A 29-year-old man without organic heart disease who had a history of six episodes of syncope following sudden cessation of strenuous exercise over the last 18 years was reported. Resting electrocardiogram and 24-hour electrocardiographic monitoring did not show any rhythm disturbance or ischemic changes. Sinus node recovery time, sinoatrial conduction time and A-V conduction were normal on electrophysiologic study. Asystole with syncope occurred immediately following sudden cessation of strenuous exercise and following release of intrathoracic pressure during Valsalva's maneuver performed after subcutaneous administration of 0.5 mg of epinephrine. However, Master's single two-step test and Valsalva's maneuver performed without epinephrine could not evoke asystole. It was assumed from these results that transient overactivity of the autonomic nervous system and sympathetic-parasympathetic interactions were the underlying factors responsible for the occurrence of asystole following sudden cessation of strenuous exercise in the present case.

Adult↗
PubMed1987

Continuous measurement of coronary sinus oxygen saturation after cardiac surgery.

To estimate the balance of myocardial oxygen supply and demand after cardiac surgery, we used fiberoptic reflection oximetry to measure continuously the coronary sinus oxygen saturation (ScsO2) in six patients. ScsO2 decreased with massive bleeding, atrial fibrillation, after DC countershock, and continuous iv infusion of hydralazine, phentolamine, and dibutyryl cyclic-AMP. ScsO2 increased with iv infusion of nicardipine or nitroglycerin, suggesting an improved oxygen metabolism in the myocardium. Continuous ScsO2 measurement provides such on-line information on myocardial oxygenation in postoperative patients.

Adult↗