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Biomedical subjects

S Ohno

Publications and source records attributed to S Ohno.

At least 991 records · Page 55Linked to original sources

In vitro and in vivo effect of PC 904, a new broad-spectrum penicillin, on ocular strains of Pseudomonas aeruginosa.

The in vitro and in vivo activities of PC 904 were tested against Pseudomonas aeruginosa isolated from infected eyes and were compared with carbenicillin and gentamicin. By the microtiter plate method, we tested 30 strains of P. aeruginosa in vitro; PC 904 was very active against 29, but one strain was resistant. In a comparative study, PC 904 was more active than carbenicillin but less active than gentamicin. In vivo tests were conducted on rabbit corneas infected with a strain of P aeruginosa isolated in El Salvador. At moderate and high dosage levels, PC 904'S efficacy was comparable to carbenicillin's but much less than gentamicin's. When tested for ocular toxicity, the subconjunctival administration of PC 904 was well tolerated. The drug's greater activity in vitro than in vivo was probably due to its high serum-binding capacity.

Ampicillin↗

Detection of a nuclear, EBNA-type antigen in apparently EBNA-negative Herpesvirus papio (HVP)-transformed lymphoid lines by the acid-fixed nuclear binding technique.

In agreement with the findings of previous authors, we could not detect a virally determined nuclear antigen in Herpesvirus papio (HVP)-transformed baboon lymphoid lines by anticomplementary staining in situ, as for EBNA. However, by means of our recently developed acid-fixed nuclear binding technique an EBNA-like antigen could be readily demonstrated, after extraction from both producer and non-producer lines. We propose to designate the antigen as HUPNA. It can be detected by a human anti-EBNA antibody, suggesting cross-reactivity, if not identity, between EBNA and HUPNA. HVP-DNA carrying non-producer lines, negative for in situ ACIF stainability but capable of yielding HUPNA by the nuclear binding technique, can be superinfected with EBV, with brilliant EBNA expression as the result, suggesting that the defective in situ staining is a property associated with the baboon HVP, rather than the baboon lymphoid cell per se.

Acetates↗

Central aromatization of testosterone in testicular feminized mice.

Aromatization of testosterone was examined in hypothalamic and cerebral cortex tissues from 32 mice--10 normal males, 10 normal females, 2 carrying the testicular feminized gene (Tfm) and 10 Tfm with the modifying (Ohv) gene. Total aromatization was 1.5 times greater in normal males than females. In both forms of Tfm, conversions were equal and similar to normal females.

Androgen-Insensitivity Syndrome↗

Vogt-Koyanagi-Harada syndrome.

We studied 51 patients who developed Vogt-Koyanagi-Harada (V-K-H) syndrome after corticosteroid therapy. The final visual acuity was better than 6/15 (20/50) in 50%, and less than 6/60 (20/200) in 25% of the patients. The severity and extraocular manifestations of this disease also appeared to be less than observed in patients before the clinical use of corticosteroids. Corticosteroid therapy probably altered the clinical picture in this disease, although other possibilities, including a skewed patient population, may account for these differences.

Adolescent↗

Testis-determining H-Y antigen in XO males of the mole-vole (Ellobius lutescens).

The XO sex chromosome constitution has been found in both sexes of the mole-vole (Ellobius lutescens) belonging to the rodent family Microtinae. This enigmatic species has apparently been enduring a 50% zygotic lethality. The current serological study revealed the presence in XO males and the absence from XO females of H-Y (histocompatibility Y) antigen. In all the mammalian species studied thus far, the expression of H-Y antigen strictly coincided with the presence of testicular tissue and not necessarily with the presence of the Y chromosome. The testis-organizing function of the H-Y gene appears to have been confirmed. In the mole-vole, X linkage of the testis-organizing H-Y gene is favored over its autosomal inheritance. Only X linkage of the H-Y gene creates a compelling evolutionary need to change the female sex chromosome constitution from XX to XO, and to abandon the dosage compensation by an X inactivation mechanism, so that the nonproductive XH-YX zygote can be eliminated as an embryonic lethal. With regard to the electrophoretic mobilities of three X-linked marker enzymes, however, a genetic difference between the male-specific XH-Y and the female-specific X was not detected. This might reflect a relatively recent speciation.

Animals↗

Identification of a purified complement-fixing antigen as the Epstein-Barr-virus determined nuclear antigen (EBNA) by its binding to metaphase chromosomes.

A soluble complement-fixing antigen carried by Epstein-Barr virus (EBV)-transformed human cells has been previously extracted from cell nuclei and purified by DNA-cellulose chromatography [Luka, J., Siegert, W. & Klein, G. (1977) J. Virol., in press]. On addition of this antigen to methanol/acetic acid-fixed metaphase chrmosomes, followed by exposure to human sera containing antibodies against the EBV-determined nuclear antigen (EBNA), brilliant positive staining was obtained by anti-complement immunofluorescence. There was no staining after exposure to EBV-negative sera. Moreover, a nuclear protein fraction, prepared from an EBV-negative cell line in an analogous fashion, failed to induce the staining reaction. These data identify the soluble purified antigen as the EBV-determined nuclear antigen. The purified antigen has a molecular weight of 174,000 +/- 15,000, as determined by sucrose gradient centrifugation and gel filtration experiments. In neutral buffers containing 0.5-1.0 M NaCl, the antigen dissociates into a form of approximately one-half the original molecular weight with retained complement-fixing activity. This "monomer" has a molecular weight of 98,000 +/- 8,000.

Antigens, Viral↗

Alteration of cell-surface antigenicity of the mouse plasmacytoma. II. Lack of correlation between synthesis of myeloma protein and alteration of surface antigen.

The correlation between the changes of immunoglobulin synthesis and the surface antigenicity was analyzed by cytotoxicity and quantitative antibody-absorption tests with the cells of immunoglobulin-producing and nonproducing mouse plasmacytoma. IgA-synthesizing BLAB/c plasmacytoma 58-8 and the non-IgA-synthesizing variant of the 58-8 (nonproducer) were killed with rabbit anti-58-8 plasmacytoma cell antiserum, C3H/He anti-BALB/c spleen cell antiserum, and (C57BL/6 X DBA/2)F1 anti-BALB/c plasmacytoma cell MOPC-31C antiserum plus complement, only when the cells were pretreated with pronase. Quantitative absorption tests revealed that the nonproducer, 58-8 had the same amount of plasmacytoma antigen of 58-8 and PC.1 antigen, and a greater amount of H-2d antigen, as did producer 58-8. The same analysis was carried out for the C3H mouse plasmacytoma X5563, which has an M-component of IgG2a. The nonproducer X5563 had a greater amount of H-2k antigen and a smaller amount of the plasmacytoma antigen of X5563 than did the producer X5563. No detectable PC.1 antigen was observed at surfaces of the producer and the nonproducer X5563 cells.

Animals↗

Purification and characterization of active component and active fragment of colicin E3.

1. Two components of colicin E3, namely proteins A and B, were prepared by means of an improved method. 2. Protein A thus obtained was more than a thousand times as active as native colicin E3 when they were assayed in terms of activity for ribosome inactivation. 3. Protein A was reconstituted to colicin E3 simply by mixing with protein B. 4. Trypsin digestion of colicin E3 yielded two fragments, T1 and T2, probably by cleaving one specific bond of the A moiety of colicin E3. 5. T2 was a complex of T2A and B proteins. T2A showed an activity equivalent to that of protein A when assayed in the in vitro system, and its activity was neutralized by protein B. Thus T2A was assigned as an active fragment of protein A. 6. T2A has a characteristic amino acid composition rich in the basic amino acid, lysine. 7. The structure and function of the colicin E3 molecule is discussed based on the results obtained with its components as well as with fragments of the components.

Amino Acids↗

HLA antigens and antinuclear antibody titres in juvenile chronic iridocyclitis.

HLA antigen frequencies and antinuclear antibody titres were studied in 43 patients with juvenile chronic iridocyclitis. We did not detect an increased incidence of HLA-B27 in patients having chronic iridocyclitis associated with juvenile rheumatoid arthritis or in patients with "chronic iridocyclitis in young girls". Both groups of patients had a statistically significant increased incidence of antinuclear antibodies. However, these antibodies were detected more frequently in patients with chronic iridocyclitis associated with JRA than in patients with "chronic iridocyclitis in young girls".

Adolescent↗