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Biomedical subjects

T Kohno

Publications and source records attributed to T Kohno.

At least 415 records · Page 23Linked to original sources
PubMed1984

Enzymatic isomerization and epimerization of D-erythrose 4-phosphate and its quantitative analysis by gas chromatography/mass spectrometry.

An enzyme preparation from beef liver catalyzed the isomerization and epimerization of D-erythrose 4-phosphate to D-erythrulose 4-phosphate and D-threose 4-phosphate. The presence of D-erythrulose 4-phosphate and D-threose 4-phosphate was demonstrated by several analytical methods. After dephosphorylation, the presence of D-erythrulose and D-threose was confirmed by thin-layer chromatography, gas-liquid chromatography and an enzymatic method depending upon D-erythrulose reductase. The enzymatic products were also identified and simultaneously quantitated by a new procedure using gas chromatography/mass spectrometry. Each of three tetroses was distinguished by the combination of the reduction with sodium borodeuteride and the determination of relative intensities of the ion pairs m/z 379 and 380 of sugar tetritol trifluoroacetate. By gas chromatography/mass spectrometry, we observed that D-threose 4-phosphate was also converted into D-erythrulose 4-phosphate and D-erythrose 4-phosphate. At the equilibrium, about 90% of the tetrose 4-phosphate existed in the form of D-erythrulose 4-phosphate. On the basis of gas chromatography/mass spectrometric evidence together with gas chromatographic and thin-layer chromatographic patterns, it is suggested that the single enzyme of the beef liver catalyzed both reactions of isomerization and epimerization of aldotetrose 4-phosphate.

Animals↗
PubMed1984

Expression of calf prochymosin in Saccharomyces cerevisiae.

A yeast strain which synthesizes activatable calf prochymosin (also known as prorennin) has been constructed by transformation with a vector carrying the methionyl-prochymosin coding sequence attached to efficient yeast transcriptional promoter and terminator sequences. Cloned preprochymosin cDNA was altered by restriction endonuclease cleavage and addition of a synthetic oligonucleotide to yield a DNA sequence encoding methionyl-prochymosin. This methionyl-prochymosin gene was ligated to a yeast chromosomal fragment containing the GAL1 promoter, and the construction was placed in an Escherichia coli-Saccharomyces cerevisiae shuttle vector with or without a transcriptional terminator DNA fragment from the yeast SUC2 gene. In yeast the two constructions result in equal amounts of prochymosin protein and mRNA. The prochymosin from yeast is activatable to chymosin by incubation at low pH and exhibits milk-clotting activity indistinguishable from calf chymosin.

Animals↗
PubMed1984

A case of cubital tunnel syndrome caused by the snapping of the medial head of the triceps brachii muscle.

A rare case of cubital tunnel syndrome caused by the snapping of the medial head of the triceps brachii muscle in a 20-year-old man was reported. The ulnar nerve was compressed by the medial head of the triceps, which snapped from the back, and was constricted at the tendinous arch of origin of the flexor carpi ulnaris. Medial epicondylectomy with division of tendinous arch was carried out, and the postoperative course was satisfactory. Our case is compared with four cases reported previously.

Adult↗
PubMed1984

Free vascularized fibular graft.

A case of severe bone and soft-tissue injury of the anterior side of the lower leg is presented. Extent of loss of the tibia was 20 cm. Loss of tibia was covered with free vascularized fibular graft extended to 26 cm, which appears to be the longest ever reported. Repair was successful.

Adult↗
PubMed1984

[Surgical treatment and radiation therapy for glioblastoma multiforme, with special reference to intraoperative radiotherapy].

We studied the effects of increased-dose radiation therapy in terms of survival time and improvement in the quality of life in 50 glioblastoma patients with minimal residual tumors. 1) Intraoperative radiotherapy ( IOR , 1,000-2,000 rad) was applied in 13 cases; the 2-year survival was 41.6%. However, in 9 patients who had undergone macroscopic total removal the 2-year survival rate was 68.6%. 2) Wide resection with necrotomy after conventional external irradiation was used in 9 cases and conformation irradiation was added; their 2-year survival was 44.4%. 3) In 22 patients who received only conventional irradiation following surgery, the 2-year survival was 7.5%.

Adult↗
PubMed1984

[Synchronization chemoradiotherapy for malignant gliomas].

Cellular synchronization chemoradiotherapy was performed in 122 patients with glioblastoma and malignant astrocytoma (GrIII) registered between April 1977 and August 1982. The study was a non-randomized clinical phase II trial. The chemotherapeutic agents employed as synchronizers during the irradiation were VM26 (epipodophyllotoxin) and vincristine (VCR) as plant alkaloids and ACNU as a nitrosourea. Either VM26 or VCR was administered on D1, D2 and D3 at the dosage of 1 mg/kg (0.025 mg/kg-VCR) body weight. ACNU was administered on D2 and D3 at the dosage of 1 mg/kg body weight. The duration of the chemotherapy was eight to fourteen days at the initial induction stage and almost eight weeks at the maintenance stage. Thus, two synchronization arms of VM26 + ACNU and VCR + ACNU were employed. The regimen-VM 26 + ACNU + Radiation (Rad) could yield the initial induction of CR + PR-30%, NC-50%, and PG-15% in 58 cases. Long-term survival, calculated by the cumulative survival rate, was as follows: one year, 58%; two years, 42%; three years, 32%; four years, 30%, and five years, 25%. The regimen VCR + ACNU + Rad could yield the initial induction of CR + PR-28%, NC-49%, and PG-23% in 64 cases. The cumulative survival rate was calculated as follows: one year, 55%; two years, 42%; three years, 27%; four years, 22%, and five years, 22%. As a control, particularly for the survival rate, the data of the All-Japan Registry were revised to correspond to our study population. The survival rate of simple radiation cases thus revised was as follows: one year, 43%; two years, 23%; three years, 11%; four years, 7%, and five years, 5%. The comparison between VM 26 plus ACNU and VCR plus ACNU yielded a higher initial induction response of 35% for the former (vs. 28% for the latter), although it is difficult to make a judgement on the excellence of the regimen involving VM 26 plus ACNU, because this trial was clinical phase II. On the other hand, compared with the data from the All-Japan Registry, each regimen of cellular synchronization radiation therapy could achieve statistically more excellent responses both in the initial induction and the long-term survival (p less than 0.01). Thus, cellular synchronization radiation therapy is a hopeful therapeutic method for malignant glioma, with less side effects and statistically confirmed higher responses.(ABSTRACT TRUNCATED AT 400 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

New suppressors of frameshift mutations in Salmonella typhimurium.

Several new types of suppressor mutants have been isolated. These were identified among revertants of mutants originally generated by mutagens other than the acridine-derived ICR191. The new suppressors correct mutations other than those with runs of C or G which are recognized by the previously described suppressors. Several frameshift mutations are corrected by more than one suppressor type. Apparently, the DNA base sequence near these mutant sites includes sites of action for several distinct suppressor types.

Base Sequence↗
PubMed1983

Genetic characterization of the sufj frameshift suppressor in Salmonella typhimurium.

A new suppressor of +1 frameshift mutations has been isolated in Salmonella typhimurium. This suppressor, sufJ, maps at minute 89 on the Salmonella genetic map between the argH and rpo(rif) loci, closely linked to the gene for the ochre suppressor tyrU(supM). The suppressor mutation is dominant to its wild-type allele, consistent with the suppressor phenotype being caused by an altered tRNA species. The sufJ map position coincides with that of a threonine tRNA(ACC/U) gene; the suppressor has been shown to read the related fourbase codons ACCU, ACCC, ACCA.--The ability of sufJ to correct one particular mutation depends on the presence of a hisT mutation which causes a defect in tRNA modification. This requirement is allele specific, since other frameshift mutations can be corrected by sufJ regardless of the state of the hisT locus.--Strains carrying both a sufJ and a hisT mutation are acutely sensitive to growth inhibition by uracil; the inhibition is reversed by arginine. This behavior is characteristic of strains with mutations affecting the arginine-uracil biosynthetic enzyme carbamyl phosphate synthetase. The combination of two mutations affecting tRNA structure may reduce expression of the structural gene for this enzyme (pyrA).

Base Sequence↗
PubMed1983

[Adjuvant immunotherapy with levamisole for malignant glioma].

The long-term therapeutic results in patients with glioblastoma multiforme and malignant astrocytoma were compared between 15 cases of levamisole treated group and 18 cases of control group similar in method and time of treatment to the levamisole treated group. As the result, it was found that the prolongation of life was noted in the levamisole treated group compared with the control. In adult patients, the levamisole treated group survived significantly longer than the control group (p less than 0.05). There is, however, no significant difference of prolongation of the survival time between the levamisole treated (8 cases) and control (8 cases) groups, both which were pretreated by chemoradiotherapy using ACNU and vincristine. This paper refers also to side effects of levamisole.

Adolescent↗
PubMed1983

Fibronectin and laminin distribution in bovine eye.

Using immunofluorescent techniques we have examined the distribution of the glycoproteins, fibronectin and laminin, in bovine eyes. As expected, both fibronectin and laminin were present in blood vessel walls and in all basement membranes, including the internal limiting membrane of the retina. Fibronectin, but not laminin, was observed arranged in fine fibrillar arrays within the vitreous body. The presence of fibronectin in the vitreous cortex and the occurrence of both proteins in the internal limiting membrane of the retina provide a morphologic suggestion of a role for fibronectin and laminin in vitreoretinal adhesion.

Animals↗
PubMed1983

[Second-look operations and chemotherapy for malignant tumors of the brain].

Second-look operations for glioblastomas, one of the most malignant types of brain tumor, were performed after the administration of chemotherapeutic treatments of general-VM 26 plus ACNU, local-MTX, or interferon-beta in each of ten, two, and three cases, respectively. Patients who had received the treatments were divided into two groups, living and deceased, as of August 1982. Therapeutic evaluation was performed with clinical parameters. Among the cases of CR, one (a 14-year-old female) had undergone surgery four times in the four years following onset, and no trace of tumor shadow appeared on the CT grams that were taken one month after the last surgery. Her performance was evaluated as almost 100% (ECOG). In cases of local administration, one case, which had been treated with IFN-beta, demonstrated an apparent decrease in the growth fraction and a pronounced decrease in tumor progression potency. Cell kinetic analyses were also performed, and cell cycle time and growth fraction were estimated by computer with the aid of flow cytometry. Efficacious chemotherapy yielded a decreased value of the growth fraction and an increase in cell cycle time. The decreased value of the growth fraction demonstrates especially well the effectiveness of a chemotherapeutic regimen. The cell kinetic analyses aided in the rational establishment of a chemotherapeutic regimen. Second-look operations for malignant brain tumors will enable more effective refinements in chemotherapeutic regimens and more successful results.

Adolescent↗
PubMed1983

Experimental macular edema of commotio retinae: preliminary report.

Experimental macular edema of commotio retinae was studied in rhesus monkeys. Clinically, opacification of the retina in these experimental animals closely resembled commotio retinae of man. No pigment epithelial damage was detected by ophthalmoscopy and fluorescein angiography showed no leakage from the retinal and choroidal circulations in the macular region. Histologically, macular swelling was apparent and was due primarily to changes of the outer plexiform layer. In this layer, swelling of the axons of the photoreceptor cells was prominent. Intracellular edema was also detected in the Müller cell processes in the inner retina and in the pigment epithelial cells. Prominent changes also occurred in the inner and outer segments of the photoreceptor cells. Disruption of the blood-retinal barrier was not found using horseradish peroxidase as a tracer. We concluded that retinal opacification was due to disagreement and intracellular edema of the cellular elements of the retina, perhaps a direct result of movement of intracellular fluid in response to mechanical injury.

Animals↗
PubMed1983

Electron microscopic studies of pipestem sheathed vessel in human retina.

Histopathology of a clinically observed pipestem sheathed vessel in the retina was studied by electron microscopy. This vessel was characterized by a marked increase and disarrangement of collagen fibrils in the media and adventitia, and invasion of the cytoplasmic processes of Müller cells into the adventitia. The lumen of the vessel was extremely narrow but was preserved with healthy endothelial cells. It is suggested that increased and disarranged collagen fibrils in the vessel wall is related mainly to the ophthalmoscopic appearance of the pipestem sheathing. The infiltration of glial cells in the vessel wall may be of less significance to the pipestem sheathing.

Adult↗