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Biomedical subjects

T Mikami

Publications and source records attributed to T Mikami.

At least 739 records · Page 41Linked to original sources
PubMed1977

Age-dependent resistance of chicken of Salmonella in vitro: antibacterial activity of lysed granule fraction of splenic adherent cells.

Lysed granule fraction was prepared from splenic adherent cells from 0-day-old to 2-month-old chickens and was examined antibacterial activity to Salmonella pullorum and Salmonella sentfenberg. The activity of lysed granule fraction from 2-month-old chickens was exhibited at pH 5.0 but not exhibited at pH 6.0 or 7.0 to both serotypes of Salmonella. At pH 5.0, lysed granule fraction from 0-day-old chickens revealed little antibacterial activity to S. pullorum but the activity increased with increasing age. At 240 min of incubation, 60% and 95% of S. pullorum were inactivated in lysed granule fractions from 7-day-old and 2-month-old chickens, respectively. High antibacterial activity to S. senftenberg was observed in lysed granule fraction from 2-month-old chickens in which 99.6% of the bacteria was inactivated during 240 min; In lysed granule fractions from 0-day old and 7-day-old chickens, 90% of S. senftenberg was inactivated during 60 min but the number of bacteria increased conversely after incubation for 240 min. Changes in enzymatic activities of 4 enzymes in the lysed granule fractions from various ages of chickens were examined. beta-Glucronidase increased statistically significantly to 2.4 and 7.6 times from 0-day-old to 7-day-old and 2-month-old chickens, respectively. Acid phosphatase and alkaline phosphatase increased slightly but not significantly different, and enzymatic activity of myeloperoxidase was scarcely detected.

Age Factors↗
PubMed1977

Distribution of immunoglobulin and secretory component containing cells in chickens.

Distribution of immunoglobulin (Ig)-containing cells and secretory component in internal organs of two 15-day-old embryos and 17 chickens, 1 to 480 days old, were examined by fluorescent antibody technique. In 15-day-old embryos, Ig-containing cells were not found in gut, bursa, spleen, or thymus. The bursa of Fabricius synthesized IgM, IgG, and IgA in as young as 1-day-old chicks. In extrabursal organs, IgM-containing cells were already present in intestine of 1-day-old chicks, but IgA-containing cells appeared in intestine, thymus, and spleen between the 3rd and 7th day after hatching. Very few IgG-containing cells were in intestine on the 3rd and 7th day after hatching. Secretory component was found in epithelial surfaces of intestine and ductus choledochus of most chickens examined. The presence of secretory component and IgA-containing cells in intestine supported the existence of secretory-immunologic system in chickens.

Animals↗
PubMed1977

Dextran derivatives in single and combination chemotherapy against transplantable mouse ascites and solid tumors.

Dextran, a typical homopolysaccharide without antitumor activity, was modified by palmitoylation and/or phosphorylation to yield three derivatives: palmitoyldextran phosphate, dextran phosphate, and palmitoyldextran. Of these compounds, only palmitoyldextran phosphate showed growth-inhibitory activity against Ehrlich solid tumor in mice. In combination therapy with mitomycin C, bleomycin, cyclophosphamide, and 5-fluorouracil, palmitoyldextran phosphate manifested strong synergistic effects against both Sarcoma 180 ascites and L1210 leukemic tumors. The compound is not directly cytocidal against Sarcoma 180 ascites tumor, but it appears to act via activation of peritoneal macrophage. The antitumor activity of palmitoyldextran phosphate apparently is mainly due to immunological host-mediated mechanisms.

Animals↗
PubMed1976

Relation between common antigen and membrane antigens associated with Marek's disease herpesvirus and turkey herpesvirus infections.

The appearance of two kinds of membrane antigen (MA) in Marek's disease herpesvirus (MDHV) or herpesvirus of turkey (HVT) infected cells was examined using antiserum to the common antigen (common-Ag). No early-appearing MA(EMA) was detected in these cultures until 16 hours post-inoculation, after which a number of cells in these cultures had late-appearing membrane antigen (LMA) as detected by immunofluorescence (IF). Fluids from cultures infected with these viruses were examined for the presence of the common-Ag by agar-gel precipitation (AGP) test. No common-Ag was detected until 16 hours, but after 24 hours, it was detected by AGP test. These results suggest that the common-Ag is related to LMA but not to EMA.

Animals↗
PubMed1976

Frequency-dependency of pulmonary compliance and its relation to airway conductance.

Dynamic compliance was determined in patients with 6 chronic obstructive lung diseases, 2 sarcoidosis and in 4 control healthy subjects at several breathing frequencies ranging between 0.2 and 1.3 Hz. The compliance exhibited an apparent fall with the increase in frequency of the patients, while it remained unaltered in the controls. A significant correlation was found between the frequency-dependency of compliance and the airway conductance determined plethysmographically. A similar relationship was also found in previous data appearing in the literature. Mathematical simulation based on the time constant theory revealed that the above correlation might be expected when airway obstruction occurred inhomogeneously in the peripheral region, of the lungs leaving the central airways intact.

Adult↗
PubMed1976

Maximum capacity of ventilation and efficiency of gas exchange during liquid breathing in guinea pigs.

Mechanical characteristics of liquid breathing were studied in isolated lungs of guinea pigs filled with fluorocarbons FC-75 and 77. It was found that compliance increased to 2-2.5 times, resistance increased to 20 times, and maximum expiratory flow decreased to 1/20-1/25 times the corresponding values observed in air-filled lungs. The maximum volume of ventilation during liquid breathing was then predicted to be 50 ml/min from parameters mentioned above, and about 80% of such ventilation was actually observed in anesthetized animals. Measurements on O2-uptake and CO2-output as well as gas analysis of arterial blood showed that the ventilation volume was insufficient to maintain the normal gas exchange in the animal unless body temperature was lowered. An increase in physiological dead space observed during liquid breathing suggested that slow diffusion rate of gases through the liquid was responsible for the deficiency of the gas exchange.

Animals↗
PubMed1976

Enhancing effect of a modified yeast mannan on antitumor activity of mitomycin-C.

A synthetic stearolymannan phosphate designated as SMP-Fr. I-d, consisting of three components, fatty acid, polysaccharide, and phosphate, enhanced the therapeutic effect of Mitomycin-C in mice implanted with 1 x 10(7) cells of Ehrlich carcinoma ascites form. Namely, 50% of the mice survived more than 60 days when ineffective doses of 0.5 mg/kg of Mitomycin-C and 50 mg/kg of SMP-Fr. I-d were administered intraperitoneally once daily for 7 days. SMP-Fr. I-d was found to be virtually non-toxic even in a dose of 1,000 mg/kg intraperitoneally in mice.

Animals↗
PubMed1976

Age-dependent resistance of chickens to salmonella in vitro: phagocytic and bactericidal activities of splenic phagocytes.

The phagocytic and bactericidal activities to Salmonella pullorum (strain 9-25) or Salmonella senftenberg (strain 99D) were examined in chicken splenic phagocytes from 0-day-old to 2-month-old chickens. The phagocytic activity against S pullorum increased in splenic phagocytes from chickens older than 7 days, but significant changes in activity against S senftenberg were not observed during the experimental period. The bactericidal activity of splenic phagocytes against S senftenberg was higher than that of phagocytes against S pullorum during the same period. Increase of the bactericidal activity against S pullorum was observed with increasing age, but the activity of the splenic phagocytes from 0-day-old chickens against S senftenberg was similar to that of the phagocytes from 2-month-old chickens. Although delayed hypersensitivity was confirmed by delayed wattle reaction in 2-month-old chickens sensitized with living S pullorum, the sensitization did not markedly affect phagocytic and bactericidal activities.

Age Factors↗
PubMed1975

Studies of Marek's disease herpesvirus and turkey herpesvirus specific common antigen which stimulates the production of neutralizing antibodies.

An agar-gel precipitation antigen prepared from the skin (feather-Ag) of chicken infected with JM strain of Marek's disease herpesvirus (MDHV) and cell extracts of cultures infected with either Type 2 plaque producing agent (PPA) of MDHV or turkey herpesvirus (HVT) (Type 2-Ag, HVT-Ag) had 1 precipitation line in common. Hyperimmune sera to the common antigen (common-Ag) neutralized to a greater extent by homologous antiserum. Absorption of HVT antiserum or hyperimmune serum to Type 2 PPA with common-Ag reduced their neutralizing activity. This reduction was almost complete with homologous antigen but less complete with heterologous antigen. The location of antigen in Type 2 PPA and HVT infected cells was determined using hyperimmune serum to the common-Ag in fluorescent antibody tests. Antigen mainly occurred in the cytoplasm of cells corresponding to the rounded refractile cells in the plaques, whereas unfixed cells showed antigen on the cytoplasmic membrane. The common-Ag associated with MDHV or HVT infections might be a virus structural component which is associated with the envelope.

Absorption↗