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Biomedical subjects

K Goto

Publications and source records attributed to K Goto.

At least 613 records · Page 34Linked to original sources

A serological survey on Bacillus piliformis infection in laboratory rabbits in Japan.

A total of 544 rabbit sera obtained from 6 commercial breeding facilities and 9 research institutions during 1985-1990 were tested for Bacillus piliformis antibody by an enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescent antibody test (IFAT). The antibody was detected in 53 (14.2%) rabbits from 3 breeding facilities and 30 (17.4%) rabbits from 6 research institutions, indicating the prevalence of B. piliformis infection among laboratory rabbits in Japan. The overall agreement with ELISA for immune status was 96.9% (527/544) with IFAT. In tests of the ability of ELISA and IFAT to quantitate antibody, a correlation coefficient (r) of 0.86 (P less than 0.01) was obtained by plotting the measured average log of the ELISA titer against the corresponding log of the IFAT titer.

Animals↗

Follicle-like hemicysts reorganized in monolayer culture of rat thyroid cells in the medium supplemented with isologous serum.

Monolayer culture of the cells isolated from rat thyroid glands formed a number of large and three-dimensional (about 200-microns diameter) hemicysts in media supplemented with isologous and high-concentration serum. The higher was the concentration of isologous serum, the larger was the hemicysts and the higher was the uptake of 131I of hemicysts. Substitution of heterologous serum, such as calf or fetal calf serum, for the isologous serum failed to form hemicysts.

Animals↗

Dynamic movement of hemicysts reconstructed from monolayer cultures of rat thyroid cells in isologous serum.

Time-lapse studies using cine-microscopic observation showed that the hemicysts formed in a culture of rat thyroid cells in a high concentration of isologous serum were found to arise by swelling from the monolayer sheet, gradually increase in size, and then rapidly collapse. The hemicyst volume increased linearly. We speculate that each hemicyst epithelium transport a constant volume of liquid into the hemicyst lumen.

Animals↗

Age-related changes in calcitonin gene-related peptide (CGRP)-mediated neurogenic vasodilation of the mesenteric resistance vessel in SHR.

Age-related changes in CGRP-containing vasodilator nerve activity in hypertension were studied in perfused mesenteric vascular beds isolated from SHR and normotensive rats (WKY). Perivascular nerve stimulation (PNS; 0.5-8 Hz) of both SHR and WKY preparations with active tone produced a frequency-dependent vasodilator response, which was abolished by 100 nM tetrodotoxin, 500 nM capsaicin or cold storage denervation. This response in SHR greatly decreased with age, whereas the response in WKY slightly decreased with age. The neurogenic vasodilation in 15- and 30-week-old SHR but not 8-week-old SHR was significantly smaller than that in age-matched WKY. Vasodilator responses to exogenous CGRP (0.1-30 nM) in SHR increased with age, whereas an age-related decrease in the vasodilation was found in WKY. Immunohistochemical studies showed an age-related decrease in CGRP-containing fibers in SHR. These results suggest that CGRP-containing vasodilator innervation is greatly decreased when SHR develop and maintain hypertension.

Aging↗

Prevention of cerebral vasospasm by actinomycin D.

The role of endothelin, a newly found vasoconstrictor peptide, is examined in the pathogenesis of cerebral vasospasm after experimental subarachnoid hemorrhage (SAH) in the dog. Endothelin immunoreactivity was overexpressed in the endothelium of the vasospastic basilar artery. Because endothelin synthesis is regulated at the messenger ribonucleic acid transcription level, the effect of actinomycin D, a ribonucleic acid synthesis inhibitor, was studied as a means of preventing vasospasm. It was found that treatment with intravenous actinomycin D for 5 days beginning on the day of SAH completely inhibited the development of vasospasm. This novel experimental therapy may lead not only to the elucidation of the pathogenesis of cerebral vasospasm but also to the availability of a prophylactic adjuvant therapy for patients with SAH.

Animals↗

[VAB-6 chemotherapy of advanced testicular cancers--its efficacy and limitation].

Fifteen patients with advanced testicular germ cell tumor were treated by VAB-6 chemotherapy after radical orchiectomy. CR was achieved in two (13.3%) and PR in nine (60.0%). The one, three and five year survival rates were 92.2, 64.2 and 51.4%, respectively. Nine patients (60.0%) remain with no evidence of disease (NED) after combined therapy (chemotherapy and surgery) with a median follow up of 4.3 months. We performed resection of the residual tumors and examined histologically. Out of 11 cases, four (36.3%) were with necrosis/fibrosis, two (18.2%) teratoma and five (45.5%) cancer. All of the six cases with non-cancerous tissues remain in NED. However, only two of the five cases with cancerous tissues remain in NED. We studied the NED rate based on four prognostic factors, (1) bulky abdominal diseases, (2) advanced lung diseases, (3) other metasteses, and (4) choriocarcinoma. In our analysis, advanced lung diseases and choriocarcinoma were poor prognostic factors. We should treat these poor prognostic cases initially with VP-16, ifosfamide, high doses cisplatin etc, which were used as salvaged drugs.

Adolescent↗

Cloning and nucleotide sequence of the KHS killer gene of Saccharomyces cerevisiae.

A 5.3-kbp fragment of the KHS gene was cloned from a genomic bank of Saccharomyces cerevisiae No. 115 constructed with an E. coli as the host and YEp13 as the vector. A non-killer yeast strain was transformed to a killer strain with the multi-copy vector containing the KHS gene, and the transformant could secrete 3-4 times more killer toxin into culture media than the donor, strain No. 115. The KHS toxin was purified 80-fold from the culture filtrate by gel filtration and column chromatography. The nucleotide sequence of a 2.8-kbp fragment of the KHS DNA that was enough for the expression of the killer activity was identified, and we found an open reading frame consisted of 2124 bp. Comparison of the open reading frame and N-terminal amino acid sequence of purified KHS toxin, suggested that the presumed peptide from the KHS gene might be processed between 36Gln and 37Ala before secretion.

Amino Acid Sequence↗

[Two cases of downhill esophageal varices associated with superior vena cava syndrome due to lung cancer].

Two cases of downhill esophageal varices associated with superior vena cava syndrome due to lung cancer are reported. Case 1 was a 68-year-old male with swelling of the upper right half his body. Chest X-ray film showed a mass shadow in the upper right lung field. Small cell lung cancer completely obstructed the superior vena cava. Esophagoscopy showed four striated downhill esophageal varices (F1, CB, RC(-]. After treatment with concurrent chemoradiotherapy, he had a partial response and the varices disappeared. Case 2 was a 55-year-old male with productive cough. The superior vena cava was narrowed by squamous cell lung cancer, with good collateral pathways. Three striated downhill varices (F1, CW, RC(-] were present. Concurrent chemoradiotherapy resulted in partial response, but the number of striated varices increased to four and CB, and extended downward. Left jugular venography revealed collateral veins to the esophagus, although bilateral brachial venography revealed no collaterals. Dynamic CT with bolus injection of contrast medium via the left jugular vein demonstrated esophageal varices. There are few reports on the blood flow of downhill esophageal varices.

Aged↗

Analysis of ethyl alcohol concentration in blood using gas chromatography equipped with blood gas sampler.

We compared the method using blood gas sampler with head space method for analysis of ethyl alcohol concentration in blood. The introduction mechanism of sample into gas chromatography is similar to pyrolyzer, but this apparatus is less complex than pyrolyzer. The calibration curve analyzed using BGS-1A became linear from 0.0 mg/ml and 6.0 mg/ml ethyl alcohol concentration as same as head space method. But, the linearity was worse than head space method. The linearity at low concentration of ethyl alcohol was better than at high concentration. The slopes of calibration curve of BGS-1A method and head space method were 3.5 and 4.05, respectively. These values were very close. After one assay, sample was reinjected without changing the new filter paper of glass sample tube of BGS-1A. No sample accumulation was observed. Ethyl alcohol in only 0.5 microliter of blood was detectable, and this volume was considerably smaller than head space method. The quantitative analysis of ethyl alcohol in blood using blood gas sampler BGS-1A, was usable. And, this method was more convenient than the head space method. Because, the sample volume become smaller and the additional instruments (for instance, vials, air-tight syringe, incubator for heating vials and oven for heating syringe) were not needed. And the heating time for the equilibration of samples between air phase and liquid phase was not needed.

Blood Gas Analysis↗

[Clinicopathological study of meningiomas of the tentorium and its surrounding structures].

We report the clinical features, radiological studies, operative procedures and results, and follow-up data in 29 patients with meningiomas of the tentorium and its surrounding structures. The cases represented 22.5% of all the intracranial meningiomas operated on in a 15 year period and were divided into three groups, depending on their main attachments, tentorial, cerebellopontine angle (dorsal aspect of the petrous ridge) and others. Tumor size was generally large and 13 cases were larger than 5 cm. The most common tumor site was along or near the superior petrosal sinus and transverse-sigmoid junction in cases involving the tentorium, and medial to the porus acousticus in cases involving the cerebellopontine angle. Different operative approaches to these tumors were carried out, depending on their location. The tumors in the lateral or medial petrous ridge were approached mainly with a suboccipital craniectomy using a retromastoid incision. Total removal was carried out in 80% of the tentorial cases, in 46.2% of cerebellopontine angle cases, and in the 83.3% in the others. Total operative mortality rate was zero. Follow-up periods ranged up to 5 years 5 months in the tentorial cases, 4 years 6 months in cerebellopontine angle cases, and 7 years 1 month in the others. Long-term results were good in 21 cases (72.4%), fair in 3 cases (10.3%) and poor in 2 (6.9%). Three patients died due to tumor recurrence. One of them suffered lung metastasis, and two of them suffered extensive local recurrences. We recommend the retromastoid approach combined with the petrosal approach, if the CPA tumor is large enough and extends to the retroclival region.

Adult↗

[Successful treatment of huge arteriovenous malformation in the basal ganglia].

This report describes successful therapeutic results of a huge and high flow arteriovenous malformation (AVM) in the left basal ganglionic region. A 39-year-old female was admitted to our hospital presenting recent progression of aphasia, hemianopsia, hemiparesis, hemisensory disturbance on the right side. Progression of disturbance in consciousness was rapid, and the patient became comatose shortly after admission. A CT scan revealed a densely enhanced lesion in the left basal ganglia which caused aqueductal obstruction and hydrocephalus. Angiography demonstrated a huge and high flow AVM that was supplied by the anterior and posterior choroidal arteries, the lateral striate arteries and the insular branches of the middle cerebral arteries. This AVM drained into the vein of Galen via the inferior ventricular and basal vein. The draining vein was markedly dilated at the level of midbrain by a prominent stenosis of the junction between the vein of Galen and straight sinus, and it severely compressed the midbrain. Superselective embolization of the feeding arteries was done in two sessions. This was followed by surgical intervention for the embolized AVM one month after the second session. Embolization and surgery were carried out under barbiturate protection to reduce the risk of normal perfusion pressure break-through. The patient recovered well from these interventions without any hemodynamic changes and showed dramatic improvement of all focal neurological abnormalities. Postoperative angiography showed only a small residue of AVM.

Adult↗

Mechanisms of altered sensitivity to endothelin-1 between aortic smooth muscles of spontaneously hypertensive and Wistar-Kyoto rats.

Endothelin-1 (ET-1) caused a dose-dependent vasoconstriction in rat aortic strips in vitro. The sensitivity to ET-1 was significantly higher in 12-week-old spontaneously hypertensive rats (SHR) than in age-matched Wistar-Kyoto (WKY) rats. In contrast, the sensitivity was not different between SHR and WKY rats at 6 weeks of age, which was close to that of 12-week-old SHR. Receptor binding study in microsomal preparations of the aortas with [125I]ET-1 showed that maximum binding value for ET-1 receptor in 12-week-old SHR was only 1.5-fold greater than that in WKY rats and that there was no significant difference in the Kd values. K(+)-depolarization induced vasoconstrictive responses that were also augmented in 12-week-old SHR. Resting membrane potential of the aorta was significantly depolarized in tissues from 12-week-old SHR compared with age-matched WKY rats. The resting membrane potentials were similar in the aorta from 6-week-old SHR and WKY rats, and were between those of 12-week-old SHR and WKY rats. When the aortic strips from 12-week-old WKY rats were partially depolarized in high K(+)-solution or in the presence of ouabain (0.1 mM), the vasoconstrictor effect of ET-1 became similar to that on the strips from SHR in a normal solution. These results suggest that, although age-dependent changes appear to be complicated, the lower resting membrane potential may account considerably for the larger sensitivity to ET-1 in the aorta from 12-week-old SHR than that from age-matched WKY rats.

Aging↗

Effects of cycloheximide on delayed neuronal death in rat hippocampus.

The effect of cycloheximide, a protein synthesis inhibitor, on hippocampal selective neuronal death was morphologically studied in rats subjected to 10 min forebrain ischemia using a 4-vessel occlusion model. Neuronal damage in the hippocampal CA1 subfield 72 h after ischemic insult was dramatically decreased by the lasting inhibition of protein synthesis through consecutive administration of cycloheximide. Cycloheximide, which was administered once within the first 24 h of recirculation, showed protective action on ischemic cell necrosis and its most potent effect was observed when injected at 12 h of post-ischemia. After 36 h of recirculation, however, treatment with cycloheximide could no longer prevent cell death. The possibility is considered that hippocampal delayed neuronal death following transient ischemia is caused by abnormal protein(s).

Animals↗