Search PubMed⌕ Search

Biomedical subjects

N Osawa

Publications and source records attributed to N Osawa.

114 records · Page 7Linked to original sources
PubMed1966

Experimental salmonellosis. VII. Comparison of the immunizing effect of live vaccine and materials extracted from Salmonella enteritidis.

Kawakami, Masaya (Gunma University, Maebashi, Japan), Nobutaka Osawa, and Susumu Mitsuhashi. Experimental salmonellosis. VII. Comparison of the immunizing effect of live vaccine and materials extracted from Salmonella enteritidis. J. Bacteriol. 92:1585-1589. 1966.-Attempts were made to isolate the factors of live vaccine which immunize against Salmonella enteritidis infection in mice. Some effective substances were found in cellular extracts of this organism when those extracts were prepared by mild procedures. One of these substances was a heat-labile toxin (toxin L), which was found in an earlier study to be homogeneous as evidenced by chromatographic, ultracentrifugal, and serological analyses and which was phospholipoprotein in nature. Mice immunized with "toxin L" were protected against a 10 MLD challenge infection with a virulent strain to the same extent as animals immunized with live vaccine of an attenuated strain, SER. However, no agglutinin could be detected in sera of the animals given "toxin L." Another effective substance, endotoxin, a heat-stable toxin, which was extracted from the same organisms, demonstrated poor protective effect. Possible mechanisms of immunization with live vaccine in S. enteritidis infection in mice are discussed.

Agglutination Tests↗
PubMedDate not supplied

Residues of doxycycline and oxytetracycline in eggs after medication via drinking water to laying hens.

Doxycycline (DOTC) and oxytetracycline (OTC) were dissolved in drinking water (0.5 g/l) and supplied to laying hens for 7 consecutive days. Eggs laid were collected daily during and after medication, and the antibiotic concentrations in the yolk and albumin were determined by the cup-plate method with Bacillus cereus var. mycoides ATCC 11778. The concentrations of both antibiotics were increased in yolk day by day with the advance in medication, reached peaks 2 days after withdrawal and then declined gradually. Mean peak concentrations in the yolk were 6.70 micrograms/g for DOTC and 1.42 micrograms/g for OTC. Peak concentrations in the albumin occurred in the middle stage of medication, where the mean values were 12.24 micrograms/g for DOTC and 1.03 micrograms/g for OTC. DOTC was detected in albumin until 24 days after withdrawal and for 2 days more in yolk than in albumin. OTC was detected in yolk until 9 days after withdrawal. The depletion period of OTC was shorter for the albumin, where the residue disappeared in all eggs 6 days after withdrawal. In spite of similarities between DOTC and OTC in structure, DOTC was deposited in higher concentrations and lasted for a longer period in eggs. This characteristic was considered due to its greater lipophilicity, closely correlated with oral absorption and tissue penetration.

Administration, Oral↗
PubMedDate not supplied

Induction of antimicrobial activity by antitumor substances from pine cone extract of Pinus parviflora Sieb. et Zucc.

Pretreatment with two distinct antitumor substances extracted from pine cone of Pinus parviflora Sieb. et Zucc. protected mice from the lethal effects of E. coli infection. Intraperitoneal administration of these fractions transiently induced differentiation-inducing factor (DIF) with a peak at 1-2hr. The rapid decay of DIF activity from the peritoneal cavity was followed by polymorphonuclear cell (PMN) accumulation and enhancement of superoxide generation (assayed with luminol-dependent chemiluminescence (LDCL] by peritoneal exudate cells. The superoxide generation by adherent cells was similarly enhanced by pretreatment, but was only 10-20% of that of the peritoneal exudate cells. Fractions that showed comparable antitumor/antimicrobial activity were also obtained from seed shells and cones of other pine trees of Japanese and foreign origin. On the other hand, a neutral polysaccharide fraction from Pinus parviflora Sieb. et Zucc. that lacked any of these activities did not induce PMN accumulation, DIF activity or LDCL generation. The results suggest a significant role in PMN activation for the expression of antimicrobial activity induced by pine cone extracts.

Animals↗