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Biomedical subjects

Y Kitagawa

Publications and source records attributed to Y Kitagawa.

At least 415 records · Page 23Linked to original sources
PubMed1977

Immunogenicity of rice dwarf virus-ribonucleic acid.

Using rice dwarf virus (RDV)-RNA which was extracted from RDV and further purified by MAK-column chromatography, anti-RNA antibodies were produced in rabbits immunized with RDV-RNA antibodies were prods immunized with RDV-RNA-methylated bovine serum albumin complexes. The antisera, as analzyed by complement fixation, cross-reacted with synthetic double stranded RNAs (poly (A)-poly (U), poly (I)-poly (C)), but not with native or denatured DNA, rRNA, tRNA, 5 S RNA and nucleic acids from rice plants. RDV-RNA treated with heat or dimethylsulfoxide was markedly reduced in reactivity to the antisera. When RDV-RNA was digested with RNase A at low salt concentration, its complement fixation activity was abolished. In double diffusion tests, two different precipitation lines were demonstrated between the antiserum and RDV-RNA. One of the precipitation lines connected with those was formed between the antisera, poly (A)-poly (U) and poly (I)-poly (C). As regards immunoglobulin classes of the antibodies, one of the two rabbits employed had antibody activity only in IgG.

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PubMed1976

A method for producing anti-DNA antibodies in ascitic fluid of mice.

Immunological methods for the production of antibodies to DNA in ascitic fluid of DDY, A/He, and C57B1/6 mice were investigated. Relatively large volumes of ascitic fluid containing antibodies for DNA in high concentration were obtainable after seven injections of denatured ssDNA-MBSA complexes emulsified with CFA into peritoneal cavities of DDY mice. The quantity of anti-ascitic fluid from 4 to 5 DDY mice was equivalent to that of antiserum from one rabbit. DDY mice accumulation of ascites is much greater than in other strains, and the ascitic fluid contains antibodies of higher titer regardless of sex. The antibody titers in ascitic fluid are not affected by alteration of the ascites volume, and are proportional to those of the corresponding sera. Antibodies to DNA in ascitic fluid of these mice occurred exclusively in IgG as in DNA antisera.

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PubMedDate not supplied

Changes of auditory brainstem responses in electrolyte-induced myelinolysis in rats. Role of hyponatremia and hypernatremia.

Electrolyte-induced myelinolysis was produced in rats to evaluate electrophysiological derangement in the brainstem. Auditory brainstem responses (ABRs) were used to assess the brainstem function. Rats treated with hypertonic saline for 2 days had normal interpeak latencies in ABRs. Rats treated with vasopressin-induced hyponatremia alone and those with hypertonic saline after 3 days of hyponatremia had significantly prolonged interpeak latencies between waves II-III and III-IV in ABRs. These prolongations indicate electrophysiological derangement of the upper pons and mesencephalon in hyponatremic rats as well as in rats with hyponatremia followed by hypernatremic myelinolysis. In view of these data, hyponatremia may be a prerequisite for electrolyte-induced myelinolysis and electrolyte derangements such as hyponatremia, and rapidly correcting hypernatremia may be the cause of electrolyte-induced myelinolysis in rats.

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PubMedDate not supplied

Pancreas-specific venular labeling by monastral blue B in the BB rat: modulation by prostaglandins and their inhibitors.

Leaky blood vessels in the microcirculation can be detected in vivo by injecting an animal with colloidal pigments like Monastral blue B (MbB). We have previously used this labeling method in the BB rat, an animal model of spontaneous autoimmune diabetes, and detected increased vascular permeability restricted to the venules of the pancreas. The earlier data suggested that pancreata of animals susceptible to labeling contain trapped intravascular monocytes that are activated to release vasoactive mediators after phagocytosis of MbB. To explore these observations further, we investigated the effects of prostaglandins on this system. Prostaglandins are known to be important mediators of inflammatory responses and to modulate the expression of disease in other animal models of autoimmunity. We now report that MbB-induced pancreatic labeling is modulated by misoprostol (an analogue of prostaglandin E1), prostaglandins of the E series, and inhibitors of prostaglandin synthesis. The nonsteroidal anti-inflammatory drugs ibuprofen and ketorolac both reduced the intensity of labeling in susceptible BB rats in a dose dependent manner. In contrast, both misoprostol and prostaglandin E2 given at low doses induced pancreatic permeability in the labeling-resistant Wistar Furth rat. To extend this finding, we also tested much higher drug doses, since at high concentrations, E series prostanoids exert anti-inflammatory effects. We observed that large doses of prostaglandin E1, prostaglandin E2, and misoprostol all suppressed labeling in the BB rat. We conclude that presence of MbB in the pancreatic circulation of the rat induces organ specific venular leakage by an inflammatory process involving prostaglandins.

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PubMedDate not supplied

Micronucleus test with cyclophosphamide using mouse peripheral blood reticulocytes.

The usefulness of the micronucleus test using supravital staining of peripheral blood reticulocytes with acridine orange was evaluated in two laboratories after administering cyclophosphamide (CYP) as a model chemical by intraperitoneal injection (i.p.) to CD-1 mice. The frequencies of micronucleated peripheral reticulocytes (MNRETs) increased dose-dependently at each sampling time. There were no significant differences in the results obtained with this new method by the two laboratories. Although the induction of MNRETs was delayed by about 24 h compared to that of micronucleated polychromatic erythrocytes (MNPCEs) in the bone marrow, the frequencies of MNRETs and MNPCEs were almost identical at each optical sampling time, 24 h for MNPCEs and 48 h for MNRETs. Therefore, it is concluded that this method is a suitable alternative to that using femoral marrow cells.

Animals↗
PubMedDate not supplied

Cerebral blood flow and brain atrophy correlated by xenon contrast CT scanning.

Correlations between cerebral blood flow (CBF) measured during stable xenon contrast CT scanning and standard CT indices of brain atrophy were investigated in the patients with senile dementia of Alzheimer type, multi-infarct dementia and idiopathic Parkinson's disease. Compared to age-matched normal volunteers, significant correlations were found in patients with idiopathic Parkinson's disease between cortical and subcortical gray matter blood flow and brain atrophy estimated by the ventricular body ratio, and mild to moderate brain atrophy were correlated with stepwise CBF reductions. However, in patients with senile dementia of Alzheimer type and multi-infarct dementia, brain atrophy was not associated with stepwise CBF reductions. Overall correlations between brain atrophy and reduced CBF were weak. Mild degrees of brain atrophy are not always associated with reduced CBF.

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PubMedDate not supplied

High mortality and shortened life-span in patients with itai-itai disease and subjects with suspected disease.

A follow-up study was conducted from 1967 to 1987 for patients diagnosed as having itai-itai disease, subjects who were suspected of having the disease, and controls. Ninety-five subjects per category were selected after matching for age, sex, and residential area. The cumulative survival rate of the patients who had a definite diagnosis of itai-itai disease was significantly lower than that of the control group in every period after the first 3 y. The cumulative survival rate of the subjects who were suspected of having itai-itai disease and who had severe renal dysfunction due to cadmium pollution was significantly lower than that of the control group. These results demonstrate (1) the enduring negative influence of itai-itai disease on prognosis and (2) that the cadmium pollution-induced renal disorder adversely affects the health of the inhabitants of a cadmium-polluted area.

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