Search PubMed⌕ Search

Biomedical subjects

M Yoshimura

Publications and source records attributed to M Yoshimura.

At least 973 records · Page 54Linked to original sources
PubMedDate not supplied

The mechanisms underlying heart stimulation by dopamine, with special reference to direct and indirect beta adrenoceptor stimulation.

1. The positive chronotropic and norepinephrine-releasing effects of dopamine were examined in the isolated guinea pig heart, using the Langendorff model. 2. The released norepinephrine was estimated from the norepinephrine concentration measured in the post-perfusion solution using HPLC. 3. The dose-response curve for dopamine to stimulate the heart rate (HR) closely resembled that for the norepinephrine release. A selective beta 1 antagonist bisoprolol completely abolished the positive chronotropic effect, but did not affect the norepinephrine release. 4. The HR increase in response to 3 mumol/L dopamine was 54 +/- 15% (n = 14) of the control in normal hearts. The response was decreased to 15 +/- 7% (n = 6) by pretreatment with reserpine. 5. A D1 antagonist, SKF83742, (3 mumol/L) shifted the dose-response curve for the dopamine-induced norepinephrine release toward the right, indicating the involvement of D1-like dopamine receptors. 6. Voltage clamp experiments using single cells isolated from the right atrium revealed that dopamine is a weak partial agonist for beta adrenoceptors. Dopamine stimulated the L-type Ca2+ current with a threshold concentration of 3 mumol/L. 7. These findings indicate the important role of the norepinephrine release in the stimulation of beta adrenoceptors by dopamine at clinically relevant concentrations.

Adrenergic Uptake Inhibitors↗
PubMedDate not supplied

Inhibition of liver metastasis of colon cancer by in vivo administration of anti-vascular endothelial growth factor antibody.

Cancer metastasis via blood vessels is a complicated process involving a number of stages. Vascularization in the cancer stroma is essential for the metastatic process. Vascular endothelial growth factor (VEGF) is an angiogenic factor, and has important roles in tumor progression or metastasis. In this study, we developed a polycolonal antibody to VEGF and examined whether the anti-VEGF antibody could inhibit the metastasis of human xenografts expressing VEGF in nude mice. The xenograft Col-23-JCK expressing VEGF formed metastatic lesions in the liver and/or pancreas when inoculated via the portal vein (splenic vein) into nude mice. The anti-VEGF polyclonal antibody inhibited metastasis to the liver and/or pancreas (4.75+/- 3.62, anti-VEGF-treated vs. 9.73 +/- 8.24, w/o anti-VEGF treatment; Student's t-test, p=0.035). Vascularity in the metastatic lesions was also decreased by anti-VEGF treatment. These results suggest that anti-VEGF antibody administration may be therapeutically useful for prevention of colon cancer metastasis.

Animals↗
PubMedDate not supplied

Association of the missense Glu298Asp variant of the endothelial nitric oxide synthase gene with severe preeclampsia.

OBJECTIVES: A large number of studies suggest that abnormalities in nitric oxide (NO) synthesis may contribute to the development of preeclampsia. We recently identified a variant within exon 7 of the endothelial NO synthase (eNOS) gene: G to T conversion at nucleotide position 894 resulting in replacement of glutamic acid with aspartic acid at codon 298 (Glu298Asp). We analyzed the association between the Glu298Asp eNOS gene variant and preeclampsia. STUDY DESIGN: The study included 152 preeclampsia patients (35 mild, 80 severe, and 37 superimposed) and 170 control subjects. Screening for the Glu298Asp eNOS gene variant was carried out by analysis of polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The frequency of the Glu298Asp variant was significantly higher in the severe preeclampsia group (28.8%) than in the control (14.1%; p <. 01), superimposed preeclampsia (8.1%; p <.01), and mild preeclampsia (11.4%; p <.01) groups. CONCLUSIONS: We conclude that the presence of the Glu298Asp eNOS gene could be a marker of increased risk of developing severe preeclampsia.

Adult↗
PubMedDate not supplied

Cytologic detection of malignant lymphoma cells with a hairy appearance in ascitic fluid. Report of a case with immunofluorocytometric analysis.

Neoplastic lymphocytes with a hairy appearance were detected in the ascitic fluid from a case of retroperitoneal malignant lymphoma. Although the tumor cells resembled those of hairy-cell leukemia (HCL), no leukemic change was observed, and the anatomic location of the neoplastic cells was different from that seen in HCL. The tumor cells were positive for some immunohistochemical markers of HCL (i.e., CD1 9 and SIg) but were negative for others (CD11c, CD25 and tartrate-resistant acid phosphatase). Immunocytofluorometric and postmortem histologic studies showed the lesion to be a well-differentiated B-cell lymphocytic lymphoma with plasmocytic differentiation in some cells.

Aged↗
PubMedDate not supplied

Antitumor effects of 3-[p-(N,N-bis-(2'-chloroethyl)amino)-phenyl]-L- alanine conjugated with human immunoglobulin (K18).

K18 (3-[p-(N,N-bis(2'-chloroethyl)amino)- phenyl]-L-alanine conjugated with human immunoglobulin) is a newly developed antitumor agent. LD50 values of K18 in animals were quite high, suggesting its low acute toxicity. This drug showed anti-tumorigenicity not only on an experimental animal tumor (Walker 256), but also on a human tumor transplantable into nude mice (RCC-13). A distribution study clarified the unique properties of K18 to accumulate and remain in the tumor site with a high rate.

Animals↗
PubMedDate not supplied

Antitumor effect of 24R,25-dihydroxyvitamin D3.

24R,25(OH)2D3, one of the endogenous active metabolites of vitamin D3, showed suppressive effects on the proliferation of various tumor cells in vitro and a prolonging effect on the survival of P-388 bearing mice in vivo. Lewis lung carcinoma was found to cause hypercalcemia in tumor bearing mice. K-DR (24R,25(OH)2D3 (prepared by Kureha Chemical Ind.) significantly prolonged the survival of mice with Lewis lung carcinoma. K-DR also showed a suppressive effect on the growth of human osteosarcoma transplanted in nude mice.

24,25-Dihydroxyvitamin D 3↗
PubMedDate not supplied

Lewy body disease with and without dementia: a clinicopathological study of 35 cases.

The pathological basis for dementia in Lewy body disease (LBD) remains controversial. While some investigators propose that cortical lesions are responsible, others favor a subcortical basis for this dementia. Brains from 35 patients with LBD (11 demented with diffuse LBD; 12 demented and 12 non-demented with a brainstem type of LBD) were clinicopathologically examined to elucidate the pathological differences between demented and non-demented patients with LBD. In cases of diffuse LBD, the cortical lesions were found to be responsible for the dementia. In some of the cases (25%) with the brainstem type of LBD, the dementia was attributed to an Alzheimer pathology, while in many cases (75%), degeneration in the subcortical nuclei, mainly the nucleus basalis of Meynert, played a major role in the dementia.

Aged↗
PubMedDate not supplied

Preparation and characterization of monoclonal antibodies against an avian reovirus.

Thirteen monoclonal antibodies against avian reovirus strain Uchida were derived. Of the 13 antibodies, three (MAb1, MAb2, and MAb3) had the ability to neutralize the infectivity of the virus. MAb1 neutralized strains Uchida, CS-108, and TS-142 equally. MAb2 neutralized the same three strains, but the activity of neutralization was 10 times higher against Uchida than against CS-108 and TS-142. MAb3 neutralized only strain Uchida. It seems that MAb1 and MAb2 have a rather broad neutralization activity and that MAb3 has a type-specific activity. These data indicate that there are both type-specific and more broadly specific neutralization epitopes in avian reovirus particles, as in mammalian reoviruses. In Western blot analysis, MAb1 bound to a sigma protein of strain Uchida, so it was suggested that this protein carries the epitope of the less specific neutralizing activity.

Animals↗
PubMedDate not supplied

Characterization of Newcastle disease viruses isolated from field cases in Japan.

Seven Newcastle disease viruses isolated in Japan from 1930 to 1984 were cloned on chicken embryo fibroblasts (CEFs) and characterized biologically. All seven produced two or more types of plaques on CEFs. The plaques were classified into four types. Plaque cloning was carried out five times, and 22 cloned viruses were established. The biological characters of the cloned viruses suggested that the strains contain different clones and that their clones are different even among close cases, such as G strain and H strain.

Animals↗
PubMedDate not supplied

Diffuse type of Lewy body disease: progressive dementia with abundant cortical Lewy bodies and senile changes of varying degree--a new disease?

The term Lewy body disease (LBD) was proposed earlier to describe a disease classified into three types (A, B, and C) according to the distributional pattern of Lewy bodies in the CNS. Group A (diffuse type of LBD) shows clinical symptoms of "dementia-parkinsonism syndrome". The most remarkable pathologic feature is the widespread appearance of numerous Lewy bodies not only in the brain stem and diencephalon (as in group C), but also in the cerebral cortex and basal ganglia, which is complicated by senile changes of various degrees. Group B is the transitional type between groups A and C. Group C (brain stem type of LBD) is identical with idiopathic Parkinson's disease. In this paper, 12 of our cases with diffuse type LBD were studied clinicopathologically and compared with eight similar cases in the literature. The neuropathologic substrate of progressive dementia in this disease is also discussed. LBD is a clinicopathologic entity; the diffuse type of LBD, a special form of this disease, presents mainly a presenile dementia.

Aged↗
PubMedDate not supplied

Serotypes of avian infectious bronchitis virus isolates from field cases in Japan.

Eight etiologic agents isolated from field cases in Japan were identified as isolates of infectious bronchitis virus by agar-gel diffusion, buoyant-density determination on sucrose-density centrifugation, and morphological study by electron microscope of the purified viruses. In studies of the antigenic relationships of the eight isolates and six known infectious bronchitis viruses, antigenic diversity of these viruses was recognized from the degrees of relatedness using a plaque reduction in the "constant-virus decreasing-serum" method.

Animals↗
PubMedDate not supplied

Modification of three avian viruses passaged in Chinese hamster lung cells (Don) in pathogenicity to chicken embryo.

The Beaudette 42 strain of avian infectious bronchitis virus, Sato strain of Newcastle disease virus, and Uchida strain of avian reovirus were passaged in Chinese hamster lung cells (Don), and some properties were examined. The Don-passaged strains showed a difference in replication in Don and chicken embryo kidney cells in one-step growth curve examinations and a partial modification in pathogenicity to chicken embryos; nevertheless, neutralization tests revealed no serological alteration.

Animals↗
PubMedDate not supplied

Isolation, identification, and plaque titration of parvovirus from Muscovy ducks in Japan.

Muscovy ducks (Cairina moschata) showed abnormal feathering, leg weakness, and high mortality. A virus was isolated from these ducks after several blind passages in embryonating Muscovy duck eggs. The isolate was resistant to chloroform, to pH 3.2, and to 65 C for 30 min. Electron microscopy showed that the isolate was an icosahedral and nonenveloped virus 20-22 nm in diameter. The isolate reacted with an antiserum against a goose parvovirus in agar gel precipitation tests. After 15 passages of the isolate in embryonating eggs, the isolate was adapted to Muscovy duck embryo fibroblasts. The adapted virus developed cytopathic effects and made clear plaques on sheets of the fibroblasts. When 5-iodo-2-deoxyuridine was added to the culture medium, virus growth was inhibited. From the data shown above, the isolate was identified as a goose parvovirus.

Animals↗
PubMedDate not supplied

HSP47 as a possible marker for malignancy of tumors in vivo.

We have developed a rat monoclonal antibody against mouse HSP47 (designated as NK47) and investigated the expression of HSP47 in several mouse ascites and solid tumors. The expression of HSP47 was not detected in ascites tumors such as P388 and Ehrlich ascites tumors while HSP47 was markedly expressed in solid tumors such as Colon-26, B16 and B16-BL6 melanomas. HSP70, HSC70 and HSP90 were expressed in almost the same level among all the tumors examined. These results suggest that the expression of HSP47 decreases as the tumor becomes more malignant.

Animals↗
PubMedDate not supplied

Enhancement of the antitumor effect by the concurrent use of a monoclonal antibody and the protein-bound polysaccharide PSK in mice bearing a human cancer cell line.

The antitumor effects of a monoclonal antibody against a human cancer cell line and a protein-bound polysaccharide, PSK, obtained from cultured mycelia of Coriolus versicolor in basidiomycetes were examined. The IgG2a monoclonal antibody against the human colon cancer cell line colo 205 induced in vitro antibody-dependent macrophage-mediated cytotoxicity against the cancer cells, but only slightly suppressed the in vivo growth of the cancer cells. Concurrent use of PSK with the antibody enhanced the in vitro antibody-dependent macrophage-mediated cytotoxicity as well as the in vivo antitumor activity. These findings suggest that the combined use of a monoclonal antibody and PSK, which have different modes of action, may be useful in the treatment of cancer.

Animals↗
PubMedDate not supplied

Neocortical changes in Parkinson's disease, revisited.

In a series of 37 Parkinson's disease (PD) brains, cortical changes were reexamined by means of Bielschowsky silver impregnation and anti-ubiquitin immunocytochemistry. Compared to routine HE staining, anti-ubiquitin immunostaining revealed neocortical Lewy bodies (LBs) in a significantly higher percentage (76% vs. 32%). Neocortical senile plaques (SPs) occurred more frequently in brains with neocortical LBs than in cases without LBs (50% vs. 11%; p < 0.05). Semiquantitative assessment of neocortical LB density correlated with the frequency of occurrence and density of neocortical SPs. Dementia was confined to patients with abundant neocortical LBs, thus fulfilling histological criteria of diffuse Lewy body disease. We conclude that neocortical LBs are a very frequent feature of PD, although abundance of cortical LBs is confined only to a small subgroup with prominent dementia: diffuse Lewy body disease.

Aged↗