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Biomedical subjects

Y Yuasa

Publications and source records attributed to Y Yuasa.

At least 217 records · Page 12Linked to original sources

[Clinical experience with cefoxitin in bacterial infections of children (author's transl)].

Using a new cephamycin antibiotic, cefoxitin, clinical studies were carried out, and the following results were obtained: (1) Cefoxitin was administered to 52 children with 38 respiratory tract infections, 2 urinary tract infections, 1 acute otitis media and others, who ranged in age from 2 months to 11 years old. (2) Cefoxitin was given intravenously at a daily dose of 27.3 mg/kg to 110.5 mg/kg. (3) The overall efficacy rate was 80% in 46 cases, i.e., excellent in 10, good in 27, fair in 7 and poor in 2. (4) Clinical side effects were not seen except exanthema in 1 patient. Elevation of GOT and GPT was seen in 2 patients, elevation of A1-P in 1 and eosinophilia in 2 by laboratory tests. However, these findings were alleviated rapidly following the cessation of therapy.

Age Factors↗

Double transformation of Indian muntjac cells by avian and murine sarcoma viruses.

Avian sarcoma virus-transformed Indian muntjac cells, SR-Mm-1, formed foci by murine sarcoma-xenotropic murine leukemia virus complex [MSV(X-MuLV)] superinfection. The response of SR-Mm-1 and parental normal Indian muntjac Mm-2K cells to MSV(X-MuLV) infection was compared. Focus formation by MSV(X-MuLV) followed two-hit kinetics in Mm-2K, but one-hit kinetics in SR-Mm-1 cells. MSV(X-MuLV)-infected SR-Mm-1 cells formed larger colonies than uninfected SR-Mm-1 cells in soft agar, while no colony was formed in the MSV(X-MuLV)-infected Mm-2K cells. After infection with MSV(X-MuLV), cell clones doubly transformed by avian and murine sarcoma viruses could be established in SR-Mm-1 cells, whereas no cell clone could be established in Mm-2K cells. The doubly transformed cells were more round and refractile than SR-Mm-1 cells. No specific chromosomal change could be detected among Mm-2K, SR-Mm-1, and the doubly transformed cells. By two-dimensional polyacrylamide gel electrophoresis of cellular proteins, several changes were seen between Mm-2K and SR-Mm-1 cells. In MSV(X-MuLV)-infected Mm-2K and SR-Mm-1 cells, several similar changes in polypeptide patterns were seen as compared with uninfected cells. These results indicate that Mm-2K cells were doubly transformed by avian and murine sarcoma viruses, and MSV transformation in SR-Mm-1 cells was different from that in Mm-2K cells.

Animals↗

[Clinical results of cefoperazone in pediatric infections (author's transl)].

In order to evaluate effectiveness of cefoperazone (CPZ) in the treatment of bacterial infections of children, the clinical studies were carried out. CPZ was administered by one-shot injection to 28 patients at daily dose of 50 approximately 160 (average 89.7) mg/kg in 3 approximately 4 divided dose for 2 approximately 10 (average 5.6) days. The overall efficacy rate in 28 cases was 92.9%, i.e., excellent in 16 (57.1%), good in 10 (35.7%), fair in 1 (3.6%) and poor in 1 case (3.6%). Temporary rise of GOT and GPT or only GOT was observed in each 1 case out of 28 cases (7.1%), but any other abnormality was not observed throughout this series. Based on the above results, CPZ was thus considered to be a useful antibiotic in treatment of pediatric infections caused by Gram-positive cocci and Gram-negative rods.

Age Factors↗

Enhancement by asbestos of oncogenesis by Moloney murine sarcoma virus in CBA mice.

Five micrograms of finely ground crocidolite asbestos (UICC standard sample) were injected intraperitoneally into 3-week-old CBA mice, together with 10(5) FFU of Moloney murine sarcoma virus. Altogether 44 out of 61 mice (72.1%) so treated developed palpable intraperitoneal tumours, and half of these died of such tumours within 100 days. The same amount of quartz and carbon similarly administered gave lower tumour incidences, namely, 19.4% (3.2% fatal) and 11.9% (1.5% fatal) respectively. Only 1 out of 59 mice inoculated with the virus alone developed a palpable intraperitoneal tumour, and this regressed spontaneously within 10 days of its first appearance. No tumours were encountered in mice treated with either asbestos, quartz or carbon alone. All the neoplasms had the appearance, under the light microscope, of anaplastic sarcomas. Most of them were confined to the serosal surface of the abdominal cavity, although invasion of underlying tissues was observed in some of the animals that died. Electron microscopical examination of tumours revealed the presence of C-type particles budding off from cellular surface. Some neoplastic cells showed characteristic features of mesothelial lining cells. The role of milky spots (taches laiteuses) in oncogenesis by asbestos and virus, especially in the induction of mesothelioma, is discussed.

Animals↗

Viable deletion mutant of human papovavirus BK that induces insulinomas in hamsters.

A plaque morphology mutant (pm-522) of human papovavirus BK, which was rescued from a human papovavirus BK-induced hamster pineocytoma, was characterized and compared with a cloned wild-type virus (wt-501). Mutant pm-522 formed turbid plaques and grew more slowly than wt-501 in human embryonic kidney (HEK) cells. The immunofluorescence assay revealed that more HEK cells underwent abortive infection with pm-522 than with wt-501. Whereas wt-501 induced brain tumors and osteosarcomas, but no insulinomas, in hamsters, pm-522 induced brain tumors and insulinomas. The DNA of pm-522 was found by electrophoresis and electron microscopy to have a deletion (85 +/- 15 base pairs) and an insertion (40 +/- 10 base pairs) between map coordinates 0.708 and 0.725 from the endonuclease EcoRI cleavage site. These results demonstrate the presence of a viable deletion human papovarivus BK mutant capable of inducing insulinomas in hamsters.

Adenoma, Islet Cell↗

Autonomic nervous dysfunction in patients on long-term hemodialysis.

The level of plasma dopamine-beta-hydroxylase (DBH) activity in subjects at rest was found to be significantly lower in 12 patients on long-term hemodialysis than in a healthy 8-member control group: 28.3 +/- 7.2 and 13.6 +/- 7.6 IU/1, respectively (p less than 0.01). Following immersion of one hand of each subject into cold water (4 degrees C) for 1 min, a significant rise was observed in both groups, 6.1 +/- 4.8 IU/1 for the control and 1.6 +/- 1.4 IU/1 for the patient group (p less than 0.01). Upon tilting up the head of all subjects, activity in both groups increased significantly, but a markedly smaller rise was found in the patient group: 5.8 +/- 4.8 and 1.1 +/- 1.6 IU/1 for the two groups, respectively (p less than 0.01). The data suggest an autonomic nervous dysfunction in patients on long-term hemodialysis.

Adult↗

Phosphorylation of chromatin- and ribosome-associated proteins in cells transformed by adenovirus, murine sarcoma virus, and methylcholanthrene.

Endogenous protein phosphorylation in chromatin and ribosomes of monkey, mouse, and rat cells transformed by DNA, RNA tumor viruses, and a chemical carcinogen revealed the association of a protein of approximately 90,000 daltons (90K), which is highly phosphorylated in vitro. Peptide map analysis showed that the 90K proteins associated with these organelles of various transformed cells are similar irrespective of the species of cells and transforming agents. This species of protein could not be detected, or was scarcely detected, by phosphorylation in chromatin and ribosomes of untransformed cells and in revertants of transformed cells. These results suggest that the alteration in the pattern of endogenous protein phosphorylation in these organelles is closely related to the transformed state of cells.

Adenoviruses, Human↗

Transformation of Indian muntjac cells by murine and avian sarcoma viruses.

Indian muntjac cells were efficiently transformed by murine sarcoma virus (MSV) and avian sarcoma viruses (ASV). When colony formation of the infected cells was examined in soft agar, many colonies were formed by the ASV-injected cells but no colony was seen in the MSV-infected cells. The ASV-transformed cell clones differed among the clones in morphology, presence of inducible ASV genome, and karyotypes.

Alpharetrovirus↗

Isolation and preliminary characterization of temperature-sensitive mutants of the murine sarcoma leukaemia virus complex.

Five temperature-sensitive mutants (ts I to 5) were isolated from a stock of the Moloney strain of murine sarcoma leukaemia virus complex which had been mutagenized by ultraviolet irradiation or N-methyl-N'-nitro-N-nitrosoguanidine. In mouse cells at the non-permissive temperature the mutants formed fewer foci of transformed cells than at the permissive temperature. The ts mutants were characterized by testing: (I) murine leukaemia virus (MuLV) clones from the ts complex, (2) the effect of additional wild type MuLV on focus formation, (3) focus formation in rat cells and (4) focus formation with pseudotypes rescued from non-producer cells. Two mutants (ts 1 and ts 3) were found to be ts MuLVs which did not possess heat labile virion proteins and were not ts in post-penetration helper functions necessary for the fixation of sarcoma virus transformation. The remaining three mutants (ts 2, ts 4 and ts 5) were ts murine sarcoma viruses which, however, showed no temperature-sensitive effect on the maintenance of transformed cell morphology nor on colony forming efficiency in soft agar.

Animals↗

Diminished vascular reactivity to a cold stress in azotemic patients.

The integrity of the neurovascular reflex arc to a cold stimulus was evaluated by the determination of the response of the limb blood flow in fifteen azotemic patients. Seven of these patients became hypotensive during the course of renal failure despite comparable hemodialysis therapy. They showed a constant low blood pressure (mean blood pressure below 90 mmHg). The reactivity index (defined as the relative change at the 15th second of stimulus) was 15.9 +/- 14.4% for these hypotensive patients, and 35.7 +/- 12.0% for the remaining eight normotensive ones, while that of healthy subjects was 48.7 +/- 8.7%. The greatly diminished reactivity of the hypotensive patients could not be explained by humoral or hormonal factors. The dysfunction of somatic nerves of the vascular geometry could not be responsible for the difference. A dysfunction of adrenergic control of blood pressure was, therefore, strongly suggested.

Adult↗

Mouse strain resistant to N-, B-, and NB-tropic murine leukemia viruses.

Mouse strain G was studied for its susceptibility to various strains of murine leukemia and sarcoma viruses. Both N- and NB-tropic Friend leukemia viruses neither induced splenomegaly nor grew efficiently in strain G mice. Using the XC test, cultured embryo cells were found to be resistant, but not absolutely, to all the tested viruses, N-tropic AKR virus, N- and NB-tropic Friend leukemia viruses, NB-tropic Rauscher leukemia virus, B-tropic WN1802B virus, NB-tropic Moloney leukemia and sarcoma viruses, and N-tropic Kirsten sarcoma virus, although the resistance to Moloney leukemia and sarcoma viruses is sometimes not as strong as that for other viruses. Thus, the strain G mice are unique among mouse strains because they show resistance that is not related to the N-B tropism of murine leukemia viruses.

AKR murine leukemia virus↗

Effect of protease inhibitors on focus formation by murine sarcoma virus.

The effect of six protease inhibitors, isolated from various species of actinomycetes, on focus formation by murine sarcoma virus was examined. Pepstatin was the only inhibitor. The treatment of cells with pepstatin at various times possibly retards the early stage of infection with murine sarcoma virus.

Animals↗