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Biomedical subjects

S Harada

Publications and source records attributed to S Harada.

At least 685 records · Page 38Linked to original sources

Peritoneal macrophages introduced into mouse foot pads enter the germinal center of regional lymph nodes nonspecifically.

Male mice were injected into their foot pads with sheep erythrocytes (SRBC) to form lymph follicles in the germinal centers in the popliteal lymph nodes. 4 weeks later, peritoneal macrophages labeled with carbon from syngeneic donors sensitized with SRBC or typhoid-paratyphoid bacilli (TAB) were separately injected into the foot pads as well. The popliteal lymph nodes were histologically examined at 6 h to 5 days after injection. Labeled macrophages appeared in the marginal sinus, migrated straight across the cortex from the marginal sinus to the lymph follicles and then entered the germinal centers. There was no difference in the mode of appearance, migration and localization of labeled macrophages in the regional lymph nodes between the mice given labeled macrophages from SRBC-sensitized donors and those given macrophages from TAB-sensitized donors. The entrance of lymph macrophages into the germinal centers of the regional lymph nodes would be immunologically nonspecific. After the injection of Pelikan ink into the foot pads, the macrophages which have taken up carbon in the peripheral tissue reached the regional lymph nodes via the afferent lymphatics and then entered the germinal centers, mainly through the medullary pole of the lymph follicles, after migrating along their immediate exterior from their marginal sinus to their medullary pole.

Animals↗

Effects of estrogen on the lymphoid regeneration and immune response in irradiated and marrow-reconstituted mice.

Various doses of estriol (E3) were given to mice intraperitoneally, immediately after lethal irradiation and marrow reconstitution. The assessment of the plaque-forming cell (PFC) response to sheep erythrocytes in the spleen and the histological assessment of lymphoid tissues were carried out 30 days later. The effects appeared to be dose-dependent and resulted in a marked suppression of the PFC response. The depletion of lymphocytes was dramatic and dose-dependent in the thymus, and in the thymus-dependent and in the thymus independent areas of the peripheral lymphoid tissues. These results suggest that E3 acts on the differentiation of stem or precursor cells toweard both the populations of T and B lymphocytes. Although E3, given on day 7 after irradiation and marrow reconstitution, suppressed the lymphoid regeneration and PFC response markedly, E3 given on day 14 had no effect. On day 7 the majority of regenerating lymphoid tissues were large pyroninophilic cells and on day 14, small lymphocytes. These results suggest that the precursor or immature lymphocytes are sensitive to E3, while mature lymphocytes are resistant. Lymphoid regeneration and PFC response were retarded in mice irradiated and reconstituted with bone marrow cells from donors pretreated with E3. These results suggest that E3 acts on the stem or precursor cells capable to differentiate in the direction of lymphoid populations and reduce their number in the bone marrow.

Animals↗

Population genetic studies of the Philippine Negritos. II. gm and km allotypes of three population groups.

Serum samples of the three tribal Negrito populations in the Philippine Islands (127 from Zambales, 87 from Bataan, and 93 from Agusan) were tested for Glm(1,2,3 and 17), and G3m(5,6,11,13,14,15,16, and 21), and Km(1). The GMpatterm of the Negritos is characterized by three haplotypes, Gm1,17;21, Gm1,2,17;21, and Gm1,3;5,11,13,14, which is also characteristic of Mongoloid-related populations, especially with high incidence of the latter haplotype. They also have the haplotype, Gm1,17;5,13,14, prevalent in Africa, New Guinea, and northern Australia, suggesting an ancient link between the Negritos and the New Guinean-Australian group. Two unusual samples of G3m(15) positive without G3m(16) observed in Zambales Negritos suggest the presence of Gm1,17;5,11,13,14,15 haplotype in the population. This appears to be unique to Zambales Negritos and the first such samples to be found.

Alleles↗

Sex differences in the formation of germinal centres in the rat thymus.

Rats of inbred DA strain were given 20 intraperitoneal injections of typhoid-paratyphoid bacilli at 10 day intervals. Thymic lymph follicles with germinal centres were formed in females but not in males. However, orchidectomy permitted the formation of large numbers of thymic lymph follicles with germinal centres in males. The formation of lymph follicles with germinal centres in the thymus was not affected by ovariectomy. These results would appear to suggest an inhibitory role of androgens on the formation of thymic lymph follicles with germinal centres. In addition, large numbers of plasma cells, mast cells, and reticular cells, or macrophages with haemosiderin in their cytoplasm, appeared in the parenchma of the thymus in close association with the formation of thymic germinal centres.

Animals↗

Amplification of plaque-forming cells in the spleen after intracloacal antigen stimulation in neonatal chicken.

Neonatal chickens were primed by multiple or a single injection with sheep red blood cells (SRBC) into the cloacal lumen and then were challenged by intravenous injection with the same antigen. Direct plaque-forming cells (PFC) in the spleen were markedly increased shortly after intracloacal priming. This enhancing effect was antigen specific and was abolished by surgical bursectomy 24 h after intracloacal priming. A similar effect was also found in mature adult chickens, although the degree of enhancement was far less than that found in neonatal chickens. These results suggest that a certain stage of B-cell differentiation in the bursa of Fabricius (BF) is regulated by antigenic stimulation.

Aging↗

Isozyme variations in acetaldehyde dehydrogenase (e.c.1.2.1.3) in human tissues.

NAD-dependent acetaldehyde dehydrogenase (ALDH) of human tissues was investigated by electrophoresis and enzyme assay. ALDH is located mainly in the liver and kidney. The isozymes consist of at least six different components. Five different phenotypes were found in a total of 68 human liver and kidney specimens. It is likely that three isozyme sets are concerned in determining ALDH types. The distribution of various phenotypes of ALDH isozyme sets is presented.

Aldehyde Oxidoreductases↗

Human liver alcohol dehydrogenase isoenzyme variations. Improved separation methods using prolonged high voltage starch-gel electrophoresis and isoelectric focusing.

Human liver alcohol dehydrogenase isozyme patterns were studied using prolonged high voltage starch-gel electrophoresis and gel-slab isoelectric focusing. Homo- and heterodimers of ADH2 locus were easily distinguished from each other. The gene frequencies of ADH2 2 and ADH2 3 in 46 random liver samples from Germany were found to be 0.044 and 0.424 respectively.

Alcohol Oxidoreductases↗

Inhibition and promotion of tumor growth by BCG: evidence for stimulation of humoral enhancing factors by BCG.

Effects of pretreatment with BCG, strain Japan, on tumor growth were studied using a transplatable methylcholanthrene (MCA)-induced fibrosarcoma in C3H/He mice. Injection of BCG7 weeks before tumor inoculation at a site distant from the tumor caused a slight inhibition of tumor growth. A low dose of tumor cells did not grow at the BCG-primed site when BCG was injected 7 and 11 weeks before the tumor. When a high dose was inoculated into the BCG-primed site, inhibition of the primary tumor occurred in mice which had received BCG 7 weeks previously, but the number of distant metastases in the popliteal lymph node and the lungs was increased in mice pretreated with BCG at any time. Furthermore, post treatment with BCG at a site distant from the tumor caused promotion of tumor growth. Enhanced antibody formation and suppression of delayed type hypersensitivity (DTH) occurred in tumor-bearing mice. BCG treatment of such mice caused a vigorously enhanced antibody formation and a marked suppression of DTH. The sera from tumor-bearing mice enhanced tumor growth. Tumor growth was suppressed in splenectomized mice. These findings suggested that antibodies against tumor-specific antigens enhanced tumor growth in this system and that BCG treatment of tumor-bearing mice stimulated formation of antibodies probably acting as blocking factors.

Animals↗

Clinicopathologic characteristics of pulmonary acinar sarcoidosis.

In 101 patients with histopathologic and clinical features compatible with sarcoidosis, a radiologic acinar pattern occurred in about 20% and was always accompanied by bilateral hilar lymphadenopathy. The radiologically acinar pattern histopathologically revealed noncaseating epithelioid granulomas and accumulations of macrophages in the alveolar spaces. Blood vessels were usually not affected by granulomas. On the other hand, a reticulonodular pattern histopathologically showed granulomas with centrally situated veins. The acinar form seems to represent the early stage of pulmonary sarcoldosis, producing primarily intra-alveolar lesions.

Adult↗

Isolation and characterization of mildiomycin, a new nucleoside antibiotic.

A new antibiotic mildiomycin, strongly active against powdery mildew, was isolated from the culture filtrate of Streptoverticillium rimofaciens B-98891. It is a water-soluble basic antibiotic and was purified by ion-exchange and adsorption chromatography. The molecular formula of the purified compound was determined to be C19H30N8O9(H2O) from physical and chemical data. The UV and NMR spectra suggested that this antibiotic is a nucleoside. On acidic hydrolysis it gave 5-hydroxymethyl cytosine which has not previously been found in nucleoside antibiotics.

Antifungal Agents↗