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Biomedical subjects

K Suda

Publications and source records attributed to K Suda.

At least 325 records · Page 18Linked to original sources
PubMed1982

[Detection and clinical significance of immune complexes in the sera of brain tumor patients].

Levels of circulating immune complexes (IC) in the sera of 87 patients with brain tumor were measured by Raji cell radioimmunoassay and Clq binding assay. The control samples were obtained from 40 healthy blood donors and 40 cerebrovascular patients. The patients with glial tumor had a high incidence of elevated level of IC than patients with non-glial benign tumor, elevated level of IC than patients with non-glial benign tumor, cerebrovascular disease and normal controls. There was a significant association between these Clq binding activity and Raji cell binding activity in the sera of glial tumor patients. As regards the sensitivity, high IC levels are more frequent among Raji cell assay than Clq binding assay. The level of IC was found to be higher in patients with recurrent glial tumor than in those with primary tumors. However, the level of IC in the sera from patients with glial tumor did not always decrease during remission after successful treatment. Our data indicate that the measurement of IC may prove useful in the management of patients with brain tumor, in particular, to detect recurrence or progression of tumor growth.

Antigen-Antibody Complex↗
PubMed1982

Methionine dependency of cell growth in normal and malignant hematopoietic cells.

Normal and malignant hematopoietic cell lines, with the exception of MOLT-3, were unable to grow in the methionine-depleted medium which was supplemented with homocysteine. Normal lymphocytes were less stimulated by mitogens in the medium containing homocysteine. Colony-forming units in culture from normal bone marrow cells were not formed in the medium in which homocysteine was substituted for methionine. These data suggest that there are no differences in the methionine requirement for cell growth between normal and malignant hematopoietic cells.

B-Lymphocytes↗
PubMed1982

5-Methyltetrahydrofolate related enzymes and DNA polymerase alpha activities in bone marrow cells from patients with vitamin B12 deficient megaloblastic anemia.

The activities of 5-methyltetrahydrofolate (5-CH3THF) related enzymes and DNA polymerase alpha were determined in bone marrow cells obtained from patients with vitamin B12 deficient megaloblastic anemia and compared with those from healthy volunteers and patients with hemolytic anemia. 5-CH3THF homocysteine methyltransferase activity was significantly lower than that in the control subjects. 5,10-methylenetetrahydrofolate reductase activity was only slightly elevated to that in the control subjects. DNA polymerase alpha activity was significantly higher than that in the control. High deoxyuridine suppression test values in vitamin B12 deficient bone marrow cells were improved by tetrahydrofolate, but not by 5-CH3THF. These data indicate that, even though the reverse reaction catalyzed by 5,10-methylenetetrahydrofolate reductase may be operative in vitamin B12 deficiency, it is not sufficient to correct the disturbance in folate metabolism in vitamin B12 deficiency. Increased DNA polymerase alpha activity may be due to compensation for disarranged DNA synthesis.

5,10-Methylenetetrahydrofolate Reductase (FADH2)↗
PubMed1982

[Changes of natural killer activity following local 60Co irradiation in intracranial tumor-bearing mice (author's transl)].

Changes of natural killer activity (NK activity) by local 60Co irradiation in intracranial tumor-bearing mice were studied by the method of 51Cr release assay. Local irradiation was administered 10 days after intracranial transplantation of 203-Glioma which had been originally induced by 20-methylcholanthrene in C 57 BL mice. Irradiation suppressed the growth of tumor and prolonged the mean survival time. The 50% survival time of untreated mice was about 2.5 weeks but that of mice treated by a single dose of 1000 rad and 1500 rad of irradiation was about 4.5 weeks and 6.5 weeks respectively. NK activity of spleen cells in these mice was serially examined. NK activity was gradually increased in mice treated by local irradiation, while it was gradually decreased in mice without treatment. On the other hand, NK activity remained unchanged in non-tumor-bearing control mice. Mice treated with 1000 rad and 1500 rad of irradiation showed 44.0% and 47.6% of % specific 51Cr release respectively 11 days after irradiation while normal mice showed 18.0%. The increased NK activity after local irradiation suggested that local irradiation might have enhanced the immunological defence mechanism against the tumor in the tumor-bearing hosts. Some characteristics of effector cells in this assay system were examined. The cytotoxicity of spleen cells was removed by the treatment of anti-BAT serum and complement but was not removed by the treatment of anti-Thy-1. 2 serum and complement. Since NK activity reflects the immunological resistance to tumors to some extent, it is felt important to clarify the significance of changes of NK activity in patients with brain tumors in relation to various treatments including surgery, radiotherapy, chemotherapy and immunotherapy in the next step.

Animals↗
PubMed1981

Effects of early monocular deprivation on development of cortico-geniculate projections in the cat.

In 16 cats monocularly deprived from 2 to 3 weeks of age, we studied 53 striate cortical cells which were identified as projecting to the dorsal lateral geniculate nucleus (LGN) on the basis of antidromic activation from LGN and of histological localization within cortical layer VI. As in the normal cat, these cortico-geniculate cells could be classified as slow, intermediate or fast, according to their axonal conduction velocities. The sampling ratio of the slow cells (mostly unresponsive to visual stimuli) was much higher than normal. On the other hand, the ratio of the intermediate (one half were simple cells) and fast cells (all except one were complex cells) was significantly lower than the norm. Also, the average axonal conduction velocities of the complex and simple cells were significantly slower than normal. These results suggest that normal maturation of cortico-geniculate cells, particularly fast and intermediate ones, is retarded or arrested by monocular visual deprivation.

Animals↗
PubMed1981

Differences of the ventral and dorsal anlagen of pancreas after fusion.

The distribution of the ventral pancreas after fusion was considered as a dorsal portion of the head containing the area surrounding the intrapancreatic view and by the distribution of "irregularly shaped islets". These special islets were not uniform in shape and contained few A, B, and D cells and many argyrophil cells with Grimelius stain. In some cases the ventral pancreas was identified macroscopically from the dorsal one by the presence of the smaller and closely packed lobuli. As for the differences of both anlagen, we emphasized "the irregularly shaped islets" and scantier fat in the ventral pancreas.

Aged↗
PubMed1981

"The choledocho-pancreatic long common channel disorders" in relation to the etiology of congenital biliary dilatation and other biliary tract disease.

The amylase level of bile and various cholangiograms was studied in 36 cases of congenital biliary dilatation. (C.B.D.) The amylase level above 10000 U/L was considered to suggest the existence of choledocho-pancreatic long common channel formation. Radiologically, the dilatation of intrahepatic bile duct was seen in 9 out of 19 (47%) Type I cases and in all (100%) Type II cases. The cystic dilatation of intrahepatic bile duct was seen in all Type I cases which have cystic choledochal dilatation. On the other hand, fusiform dilatation was seen in all Type II cases with fusiform choledochal dilatation. End to side Choledocho-pancreatic anastomosis was performed to produce an experimental model of human choledocho-pancreatic long common channel disorders, thus leading to the dilatation of the common bile duct as well as the reflux of pancreatic juice into the bile duct. The reflux of Pancreatic juice and congenital stricture due to the choledocho-pancreatic long common channel formation were considered to be the important causative factors in the etiology of C.B.D.. Furthermore, pathology of the choledocho-pancreatic long common channel disorders was found to be important in relation to the etiology of both C.B.D. and other lesions of the biliary tract and pancreas.

Adolescent↗
PubMed1981

[Modification of hepatotoxic effect of halogenated hydrocarbons on partially hepatectomized rats (author's transl)].

The effect of hepatectomy on the hepatotoxic effect of halogenated hydrocarbons was studied. Male rats received oral administration of chloroform of carbon tetrachloride at a single dose of 500 mg/kg, 3 days prior to or after the partial hepatectomy. The hepatotoxic effect of the toxins was modified in a different manner according to the time of the hepatectomy. In the animals hepatectomized 3 days after the hepatotoxins administration, histological changes of the liver were similar to those of the non-hepatectomized rats, except with an increase in the activity of GOT and GPT. Contrary, in the animals hepatectomized 3 days prior to the hepatotoxins administration, the toxic effect of the chemicals was less enhanced than in the non-hepatectomized animals.

Alanine Transaminase↗
PubMed1981

Effect of nitrous oxide on human bone marrow cells and its synergistic effect with methionine and methotrexate on functional folate deficiency.

5-Methyltetrahydrofolate homocysteine methyltransferase activity in human bone marrow cells obtained from patients undergoing surgical operation became low after about 4 hr of nitrous oxide (N2O) anesthesia. The deoxyuridine suppression test performed on these bone marrow cells also became abnormal after about 6 hr of N2O anesthesia. The incorporation of [3H]thymidine into DNA in the bone marrow cells preincubated with methionine or methotrexate was much higher after N2O anesthesia than before anesthesia. Since N2O and methionine or methotrexate have a synergistic effect on depletion of functional folate, N2O alone or in combination with methionine or methotrexate might be of value for cancer treatment and deserve clinical trials.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1980

Three groups of cortico-geniculate neurons and their distribution in binocular and monocular segments of cat striate cortex.

Among 409 neurons recorded from binocular and monocular segments of the cat striate cortex, 91 were identified as cells (C-G cells) projecting to the dorsal lateral geniculate nucleus (LGN) on the basis of antidromic activation from LGN and of histological localization of cortical layer VI. The axonal conduction velocity of these C-G cells was calculated from differences in latency between antidromic responses to electrical stimulation of LGN and the optic radiation. According to this velocity, 70 C-G cells from the binocular segment could be classified as fast (13--32 m/sec), intermediate (3.2--11 m/sec) and slow (0.3--1.6 m/sec) cells. The fast cells (47% of the total) were spontaneously active and had receptive fields of complex type. Histologically they were located mostly in the upper half of layer VI. The intermediate cells (31%) were mostly simple. The slow cells (21%) were completely silent, not driven by visual stimuli, and located mostly in the lower VI. From the monocular segment of the cortex, the intermediate cells could not be recorded, while the other two groups of cells were sampled with the same frequency as from the binocular segment. These findings suggest an existence of three functionally distinct groups of C-G cells and a possible participation of the intermediate cells in binocular vision.

Animals↗
PubMed1980

Dopamine, norepinephrine and serotonin production by an intestinal carcinoid tumor.

Substantial amounts of both dopamine and norepinephrine in addition to serotonin were found in a mesenteric metastasis of an ileal carcinoid tumor. Correspondingly, the norepinephrine-synthesizing enzymes were present in the tumor tissue and tyrosine hydroxylase was found in amounts substantially higher than the levels normally present in adrenal medullary cells. These findings confirm that the carcinoid tumors belong to the APUDomas and indicate that catecholamines might play an important role in the pathogenesis of the carcinoid syndrome.

Apudoma↗