Search PubMed⌕ Search

Biomedical subjects

T Okuda

Publications and source records attributed to T Okuda.

At least 451 records · Page 25Linked to original sources
PubMed1984

Structural polymorphism of mouse complement C2 detected by microscale peptide mapping: linkage to H-2.

Complement C2 was isolated from 17 mouse strains by immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and examined for structural polymorphism by using micro-peptide mapping. By comparing the peptide maps of tryptic digest of C2 from various strains, two allotypic variations were detected. B10 and 14 other mouse strains demonstrated C2.1 type, while a wild mouse line (M.Mol-Ohm) and one B10 congenic strain, B10.MOL.OHM, which carries the H-2 derived from M.Mol-Ohm, demonstrated C2.2 type. (B10 X B10.MOL.OHM)F1 demonstrated codominantly expressed C2 type (C2.1.2). Desialation of mouse C2 did not abolish the observed variation of mouse C2. It is concluded that an H-2-linked codominant locus controls the structure of mouse complement C2, further confirming the extensive homology of the major histocompatibility complex among higher vertebrate species.

Alleles↗
PubMed1984

Differentiation of presumptive primordial germ cell (pPGC)-like cells in explants into PGCs in experimental tadpoles.

A single blastomere containing the "germ plasm" of 32-cell stage Xenopus embryos was cultured with [3H]thymidine until the control embryos developed to the neurula stage. The explants, showing a spherical mass in which the nuclei of all cells were labeled, were implanted into the prospective place of presumptive primordial germ cells (pPGCs) in the endodermal cell mass of unlabeled host embryos of the neurula stage. Labeled PGCs as well as unlabeled, host PGCs were found in the genital ridges of experimental tadpoles. This indicates that the precursor of germ cells, corresponding to pPGCs in normal embryos of the neurula stage, in the explants migrated to genital ridges just at the right moment to become PGCs, and suggests that the developmental process progressed normally, even in the explants, as far as the differentiation of pPGCs is concerned.

Animals↗
PubMed1984

Complement receptor expression of primates and non-primates detected by the rosette formation technique.

The expression of complement receptors were studied on erythrocytes and platelets from 14 non-human primates and 3 non-primate species by rosette formation. It was found that the reactivity of erythrocytes with the cell bound complement is deeply dependent on which species are used as the complement source. The erythrocytes from Prosimian do not react with any kind of complement, while their platelets react with many kinds of complement. New World monkey erythrocytes do not react with indicator cells binding complements from guinea pig or man, while some of them react with indicators binding complements from non-human primate species. Contrarily Old World monkey erythrocytes react with complements from guinea pig, man and non-human primate. Hominoidea erythrocytes reacted with all the complements tested. Rabbit expresses C3 receptors on their erythrocytes for rabbit C3 and on their platelets for rabbit, guinea pig or mouse C3. Guinea pig expresses receptors on their erythrocytes for guinea pig and mouse C3, and on their platelets for guinea pig, mouse, rabbit and human C3. It becomes clear that not all of erythrocytes from primate and platelets from non-primate always express complement receptors as has been stated in the text books.

Animals↗
PubMed1984

Endogenous nitrogen excretion in male highlanders of Papua New Guinea.

Endogenous nitrogen excretion was examined in highlanders of Papua New Guinea. Eight highlanders were fed a semisynthetic protein-free diet with about 49 kcal/kg of energy for 11 days. At the end of this period they excreted 29.2 +/- 4.0 mg N/kg of urinary nitrogen and 13.9 +/- 2.5 mg N/kg of fecal nitrogen per day. When the values were expressed per basal metabolic rate (BMR), they were 1.25 +/- 0.19 mg N/kcal BMR for urine and 0.59 +/- 0.08 mg N/kcal BMR for feces. The total amount was calculated as 43.1 +/- 4.3 mg N/kg (1.84 +/- 0.18 mg N/kcal BMR). Endogenous urinary nitrogen excretion in highlanders was the lowest so far reported; the effects of ethnic and nutritional backgrounds on obligatory urinary N loss were examined but no clear explanation was found for the highlanders' low value.

Adult↗
PubMed1984

Outbreak of nosocomial urinary tract infections caused by Serratia marcescens.

A prolonged outbreak (December 1980 to July 1982) of nosocomial urinary tract infections appeared to be due to strains of Serratia marcescens that were resistant to currently available antibiotics. The serotyping and antibiotic susceptibility patterns suggested a few endemic strains of serotypes O13, O2/3, O12/14, and nontypable strains. These strains were isolated from the urine samples of inpatients with urinary tract infections in the urology ward and in other wards. The strains of O12/14 (gentamicin susceptible) were replaced with those of O2/3 (gentamicin resistant) between June and September 1981, whereas the other serotypes were isolated continuously. They were resistant to sulbenicillin, cefmetazole, gentamicin, and amikacin, and susceptible to micronomicin and of loxacin, a new quinolone antibiotic. Most of them were also resistant to the disinfectant chlorhexidine, which had been used widely for hand washing in the hospital.

Anti-Bacterial Agents↗
PubMed1984

Isolation, molecular properties and allotype of mouse C1q.

Mouse C1q, a subcomponent of the first component of complement, was purified from mouse EDTA plasma by a combination of precipitation with polyethyleneglycol, affinity chromatography on IgG-Sepharose, ion exchange chromatography and molecular sieving. Mouse C1q was compatible with human C1q in the sense that it shows C1 hemolytic activity by the combination with human C1-r and C1-s. The molecular weight of mouse C1q as estimated by SDS-PAGE was approximately 410,000 and almost the same as that of human C1q. After treatment of mouse C1q with 4 M urea, three distinct subunits were obtained on SDS-PAGE in non-reducing condition. Moreover it was shown that there are small, yet definite differences in the molecular weights of the subunits between the two mouse strains. Three subunits of the C1q from C3H and ICR showed apparent molecular weights of 62,000, 58,000 and 53,000 but those of DDI showed 62,000, 55,000 and 51,000. These results suggested the existence of allotype of mouse C1q, and indeed, alloantisera made by injecting the C1q of ICR to DDI reacted in Ouchterlony double diffusion test with plasma of ICR, C3H, AKR and BALB/c, but not with DDD, DKI, C57BL/10 and C57BL/6.

Animals↗
PubMed1984

The effect of divalent cations on the rosette formation via C3 receptors.

The indicator cells with the specificity for the various C3 receptors were prepared using highly purified complement components. The effect of EDTA and divalent cations on the rosette formation of these indicators with human blood cells and lymphoblastoid cells were investigated. B lymphocytes form rosettes with EACl-3b, EACl-3bH, EACl-3bi and EACl-3d irrespective of the presence of cations. PMN and monocytes form rosettes with EACl-3b and EACl-3bH independent of cations, but their formation with EAC1-3bi needs the presence of magnesium. In this case calcium shows a cooperative effect with magnesium. PMN and monocytes do not react with EACl-3d even in the presence of magnesium. Although Raji cells do not react with EACl-3b, they react with EACl-3bH independent of divalent cations. EACm has a similar reactivity to EACl-3bi, and by the treatment with trypsin it becomes similar to EACl-3d.

Calcium↗
PubMed1984

Penitricin, a new class of antibiotic produced by Penicillium aculeatum. I. Taxonomy of the producer strain and fermentation.

A novel antibiotic, penitricin (Ro 09-0804) was discovered in the culture filtrate of a fungal strain NR 5165. Taxonomic studies of the producing organism resulted in its assignment to Penicillium aculeatum. Further examination on penitricin production by other strains of this species and related taxa revealed that penitricin was produced by several other strains of P. aculeatum, but not by any available strains of the closely similar species, P. verruculosum. It was also found that copper ion was essential for production of penitricin.

Anti-Bacterial Agents↗
PubMed1984

Penitricin, a new class of antibiotic produced by Penicillium aculeatum. II. Isolation and characterization.

A novel antibiotic, penitricin, Ro 09-0804, has been produced in the culture filtrate of Penicillium aculeatum NR 5165. This antibiotic was purified by repeated extraction of culture filtrate with 1-butanol, and passage of the crude extracts through Sephadex G-10, followed by HPLC (Shodex Ionpak S-801). Physico-chemical characterization was made on penitricin, while two open-ringed penitricins B and C co-produced by the producer strain were also identified.

Aldehydes↗
PubMed1984

Penitricin, a new class of antibiotic produced by Penicillium aculeatum. III. Structural confirmation by chemical synthesis and biological activity.

A novel antibiotic, penitricin showing anti-Gram-negative activity, has been isolated from the culture filtrate of Penicillium aculeatum. Chemical and physico-chemical studies determined the structure of penitricin as hydroxymethylcyclopropenone (1), which was confirmed by chemical synthesis from propargyl alcohol. Biological activity of penitricin and several cyclopropenones as well as two metabolites, penitricins B and C was compared.

Aldehydes↗