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Biomedical subjects

T Oshiro

Publications and source records attributed to T Oshiro.

At least 73 records · Page 4Linked to original sources
PubMed1992

Crystallization and preliminary diffraction studies of hydroxypyruvate reductase (D-glycerate dehydrogenase) from Hyphomicrobium methylovorum.

Two crystal forms of hydroxypyruvate reductase (D-glycerate dehydrogenase) from the methylotrophic bacterium Hyphomicrobium methylovorum have been grown from ammonium sulphate solutions. One crystal form is triclinic, with unit cell parameters a = 60.4 A, b = 60.5 A, c = 66.3 A, alpha = 102.3 degrees, beta = 113.7 degrees and gamma = 102.7 degrees, suggesting that a dimer (monomer M(r) 38,000) occupies the unit cell. This crystal form diffracts to beyond 2.4 A resolution and is suitable for crystallographic structure analysis.

Alcohol Oxidoreductases↗
PubMed1992

Primary malignant tumors of the small intestine: analysis of 40 Japanese patients.

Forty Japanese patients with primary malignant tumors of the small intestine were reviewed. Adenocarcinoma was the most common tumor type comprising 19 patients (47%), followed by malignant lymphoma, 11 (30%), leiomyosarcoma, 8 (20%) and carcinoid tumor, 1 (3%). Adenocarcinomas and leiomyosarcomas were primarily located in the duodenum or jejunum, whereas lymphomas were more common in the jejunum or ileum. Abdominal pain (65%) and nausea or vomiting (35%) were the most common symptoms with these tumors. Barium contrast studies were able to detect 83% of these tumors. Our results also suggest that computed tomography and ultrasonography are not reliable for diagnosing jejunal tumors while superior mesenteric angiography is effective for diagnosing ileal tumors. The duodenal and ileal tumors tended to metastasize to lymph nodes while jejunal ones tended to penetrate the serosa or to disseminate into the peritoneal cavity. The percentage of tumors potentially cured by surgery and the 5 year survival rates of the leiomyosarcomas (75% and 57%, respectively) were higher than those of adenocarcinomas (42% and 10%, respectively) and lymphomas (42% and 32%, respectively).

Adenocarcinoma↗
PubMed1990

Chemo-enzymatic synthesis of optically pure l-leucovorin, an augmentor of 5-fluorouracil cytotoxicity against cancer.

Optically pure l-leucovorin was synthesized on a large scale by the combination of chemical and enzymatic processes. After reduction of folate with zinc, dihydrofolate was reduced asymmetrically to (6)-tetra-hydrofolate by use of dihydrofolate reductase from E. coli C600/pTP600, with simultaneous NADPH cofactor recycling using glucose dehydrogenase from Gluconobacter scleroideus KY3613. Calcium l-leucovorin.4H2O (113 g) was obtained from (6S)-tetrahydrofolate via 5,10-methyenyltetrahydrofolate by formylation, reflux, addition of calcium ions and floricil column chromatography, with an overall yield of 50% based on folate. The l-leucovorin showed optical purity of 99.9% de as (6S)-form.

Escherichia coli↗
PubMed1989

[Ultrastructural studies of initial calcification of mouse fetal parietal bone in vitro].

The parietal bone fragment (1.5 mm square) extracted from murine fetal calvaria (periosteum was removed) in the latter stage of gestation was cultured in alpha-MEM containing 10% fetal bovine serum over 10-day period, and the initial calcification site was subsequently examined utilizing both electron microscopy and histochemical methods. At the initial calcification site, the so-called "matrix vesicle" (width 100 nm), derived from osteoblasts which induce matrix formation, and the larger vesicular structures (width 100-600 nm) which originated from degenerated or dead cells were observed. Additionally dead osteoblast-like cells phagocytosing bone crystals participated in bone nodul formation. In the border region between the degenerated or disrupted cells and the functioning cells, multilamellar structures (mainly composed of phospholipids) were frequently observed. Concurrently it was concluded that there is a possibility of partial deposition of calcium salts on the surface of the above mentioned cells under some circumstances. Through selective decalcification, it was determined that bone trabecule was formed by fusion of respective bone noduli and degraded collagen fibrils which filled the intervening spaces. From the above results, it was evident that both the matrix vesicles derived from functioning osteoblast, and the vesicular structures derived from the degenerated or dead cells concurrently phagocytosing spicules and collagen fibrils were involved in the initial calcification process of the membranous bone in vitro.

Animals↗
PubMed1987

Active metabolism of phosphatidylethanolamine plasmalogen in stimulated platelets, analyzed by high performance liquid chromatography.

To investigate the stimulus-linked metabolism of platelet phosphatidylethanolamine plasmalogen (PEP) which is not separable from diacyl PE by conventional methods, phospholipids extracted from stimulated platelets prelabelled with 3H-arachidonate (AA) were analyzed by high performance liquid chromatography (HPLC) reported by us (Thrombos. Res. 36, 335, 1984 & 42, 461, 1986). When washed human platelets were stimulated by thrombin or A23187, the amount of PEP monitored by optical density was significantly decreased in consort with phosphatidylcholine (PC), indicating an active participation of PEP in the liberation of AA. Unlike other major phospholipids, PEP hardly incorporated 3H-AA in the resting state but upon stimulation gradual but significant uptake of 3H-AA by PEP was observed. The amount of uptake was not affected by the level of cytosolic free Ca2+ or by the amount of liberated AA, ruling out a direct participation of this unique reacylation process as negative feed back system.

Adult↗
PubMed1986

Mechanism of the cytoprotective effect of prostaglandin I2 and its analogue in human platelets.

The responsiveness of washed human platelets to thrombin was well preserved up to 72 and 96 hours, when they were stored at 4 degrees C with prostaglandin I2 (PGI2) and its stable analogue OP-41483, respectively, while the washed platelets stored with sodium citrate completely lost their responsiveness to thrombin at 48 hours. The effect of PGI2 or the analogue on the resting level of intraplatelet Ca2+ concentration ([Ca2+]i) was investigated, utilizing fluorescent Ca2+ indicator quin 2. PGI2 lowered the resting [Ca2+]i in a dose related manner in the presence or absence of the extracellular Ca2+. The similar results were obtained when OP-41483 was added to the quin 2 loaded platelets. From these results, it was concluded that the lowering of the resting [Ca2+]i may be the prerequisite for the cytoprotective effect of PGI2 or OP-41483.

Aminoquinolines↗
PubMed1985

Haptoglobin therapy for possible prevention of renal failure following thermal injury: a clinical study.

Hemolysis does not necessarily result in acute renal failure in severely burned patients, but free serum hemoglobin may play some important role in the development of renal damage. This controlled study of the effects of haptoglobin administration in severely burned patients presenting with hemoglobinuria produced the following results: As long as free hemoglobin was present in the plasma, free serum haptoglobin remained undetectable. Free serum hemoglobin dropped rapidly after haptoglobin treatment, whereas the free serum hemoglobin levels in control patients remained unchanged for at least 12 hours. The time required for macroscopic hemoglobinuria to clear showed a statistically significant difference between the haptoglobin-treated patients and the control patients. Some patients among the haptoglobin-treated group had prolonged hemolysis and hemoglobinuria which might have cleared with additional doses of haptoglobin.

Acute Kidney Injury↗
PubMed1985

[Laser acupuncture therapy for pain and vague complaints in neurosurgery].

The value of diode laser acupuncture for pain and other vague neurological complaints has been studied in chronic patients of head trauma and of cerebrovascular disease or neuralgia in head and neck regions. Gallium-Aluminium-Arsenide (Ga-Al-As) diode laser pain attenuator PANALAS-4000 manufactured by Japan Medical Laser Laboratory was used in the following specifications; wave length: 830 nm, power: 20-40 mW, frequency: 5-50 c.p.s., pulse duty: 0.9. The laser acupuncture was applied to some of the representative Chinese meridian points, local pain points and related nerves for 1 to 7 times in a week. It was given in 310 patients in our neurosurgical department. 175 of 227 patients who complained of pain and 12 of 39 patients who complained of numbness showed improvement within 24 hours, another 24 patients with pain and 16 patients with numbness showed improvement after 24 hours. No side effect was noticed. The duration of the effectiveness was about 2 or 3 days. It is very useful to apply the laser acupuncture for pain and vague complaints in neurosurgery.

Acupuncture Therapy↗
PubMed1984

Familial dysalbuminemic hyperthyroxinemia: a study of four probands and the kindred of three.

We investigated four probands, and the kindred of three, with familial dysalbuminemic hyperthyroxinemia, using the one- and two-step tests for free thyroxin and other thyroid-function tests. The results indicate that this is an autosomal dominant trait. The discovery of eight cases in our patient population, which represents about 4% of our hyperthyroxinemic patients (8/320), during eight months indicates that this aberration is more common than suspected. Its importance lies in the misinterpretation of test results and the consequent inappropriate treatment for thyrotoxicosis.

False Positive Reactions↗
PubMed1982

Multivariate analysis using a linear discriminant function for predicting the prognosis of congestive heart failure.

Some of cases of congestive heart failure (CHF) are intractable or refractory and respond poorly to conventional treatment. We have examined factors which may influence the clinical course and prognosis. The subjects were 114 hospitalized patients with CHF. Of these, 77 had a good response to treatment and were classified as the curative group (Group C) while the remaining 37 who were difficult to treat, including those with poor prognosis, were designated the refractory group (Group R). Of the various clinical background factors including the findings of laboratory and other examinations, the following 8 variables made a significant contribution to differentiation between the 2 groups: 1) heart rate (X1), 2) hemoglobin content (X2), 3) serum K (X3), 4) serum total protein (X4), 5) A/G (X5), 6) BUN (X6), 7) grade of hepatomegaly (X7), and 8) number of previous CHF episodes (X8). The linear discriminant function represented by the following equation using these 8 variables showed an excellent result in differentiating the 2 groups. Y = - 9.64 - 0.0686X1 + 0.345X2 + 1.351X3 + 1.513X4 + + 1.988X5 - 0.0876X6 - 0.792X7 - 0.737X8. When Y value is over 0, Group C is judged. When Y value is under 0, group R is judged. We concluded that the discriminant equation covering these 8 factors is a useful means of predicting the prognosis in CHF and the response to treatment.

Adult↗
PubMed1981

Treatment of angina pectoris patients with niludipine a new calcium antagonistic drug.

The antianginal effectivity of niludipine (Bay a 7168), a new calcium antagonistic drug, was investigated in angina pectoris patients, selected for admission to the trials by pre-determined strict criteria. Oral administration of from 60--120 mg niludipine daily for 4--8 weeks, resulted in the following: 1. Number of anginal attacks significantly reduced. 2. Nitrate consumption markedly lowered. 3. Investigating physicians assessed globally the clinical results of niludipine treatment on the basis of the reduction of the number of anginal attacks, nitrate consumption, improved physical ability and reports by the patients as to their subjective evaluation of the test drug. Niludipine was judged clinically effective in 21 out of 27 patients (77.8%). 4. Full records of ECGs, a necessary item for assessment, were obtained from 24 out of 27 patients. Ischemic ECGs were improved or normalized in 6 out of 24 patients (25%). 5. In the investigators' final overall assessment, including the evaluation of ECG changes, niludipine was rated effective for 20 out of 27 patients (74.1%). 6. Tolerance to the test drug was excellent. Only one patient complained of transient, mild nausea. After reduction of the daily dose, the patient completed the trial without any further appearance or complaints of side effects. Results suggest that niludipine is a useful antianginal drug in the management of coronary artery disease patients. Further clinical investigations with a larger number of patients should be conducted.

Aged↗