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Biomedical subjects

T Mikami

Publications and source records attributed to T Mikami.

At least 685 records · Page 38Linked to original sources
PubMed1981

Transient changes in ventilation and cardiac output at the start and end of exercise.

In order to clarify the nature of the regulatory mechanism of the hyperventilation observed at the transition from rest to exercise, cardiac output and ventilation changes in response to submaximal bicycle exercise given as a step function were studied in five healthy men. Cardiac output was determined non-inversively by using a type of impedance plethysmography. It was found that (1) both the cardiac output and ventilation started to increase during the first 10 sec after the start of exercise; (2) the rate of increase in the initial response was abrupt in ventilation but rather gradual in cardiac output: (3) the fast response was followed by a slow response with an exponential time course, the half response time of which ranged between 10 and 45 sec in cardiac output and between 5 and 80 sec in ventilation. The half time increased in proportion to an increase in the work rate and (4) end-tidal pressure of carbon dioxide monitored simultaneously showed a slight decrease at 10 to 15 sec after the start of exercise. It was therefore concluded from the above observation that the initial phase of the exercise-induced hyperpnea is probably of a neurogenic origin.

Adult↗
PubMed1981

Transformed phenotypes in long-term cultures persistently infected with bovine leukemia virus.

Two cell lines, 3178 and FLK, were established respectively from calf form bovine lymphosarcoma and from fetal lamb kidney cells inoculated in vitro with bovine leukemia virus. These two cell lines persistently infected with bovine leukemia virus were maintained for more than 150 passages over three years. They exhibited the characteristics of transformed cell lines in vitro: 1) anchorage independence, 2) increased saturation density and decreased population doubling time, 3) increased uptake of 2-deoxy-D-glucose and 4) tumorigenicity in athymic nude mice.

Animals↗
PubMed1981

Automatic determination of cardiac output using an impedance plethysmography.

A computer-based system which calculates stroke volume, heart rate and cardiac output automatically from the transthoracic impedance variation has been developed. A beat-by-beat determination was performed on several healthy subjects and patients with atrial fibrillation during spontaneous breathings at rest. The respiratory artifact appearing on the impedance cardiogram was canceled by (1) correcting the base line of dZ/dt for each cardiac cycle on the basis of assumption that the dZ/dt values at ECG-R waves would be invariable regardless of the respiratory phase when the respiratory movement ceases, and (2) averaging the signals for a number of cardiac cycles. Comparisons between the computed stroke volumes and those obtained from a manual calculation showed good agreement.

Adult↗
PubMed1980

Cohelical arrangement of the DNA strand in the core of Marek's disease virus particles.

Electron microscopic studies on Marek's disease virus demonstrated that fibrils of 20 to 30 A were arranged in a cohelical configuration within an electronopaque band of about 100 A thickness in the core of immature particles. These fibrils were presumed to be the DNA double helix itself. This configuration may represent an arrangement of the herpesvirus DNA.

Capsid↗
PubMed1980

Cytotoxic antibody in cattle and sheep exposed to bovine leukemia virus.

Sera from bovine leukemia virus-infected cattle and sheep lysed fetal lamb kidney cells in the presence of rabbit complement. This cytolytic activity was removed completely from the sera by absorption with bovine leukemia virus (BLV). Antiserum against surface glycoprotein antigens of BLV contained cytolytic antibody but antiserum against the internal protein p24 did not. The complement-dependent antibody cytotoxicity test employing the trypan-blue dye exclusion method appeared to be suitable for routine diagnosis of BLV infection.

Animals↗
PubMed1980

Antigenic difference between intracellular and membrane antigens induced by herpesvirus of turkeys.

The difference between intracellular antigen (IA) and membrane antigen (MA) induced by herpesvirus of turkeys (HVT) was examined by immunofluorescence analysis. Convalescent sera from chickens infected with HVT (HVT convalescent serum) and hyperimmune sera from chickens immunized with partially pruified virus (anti-HVT particle serum) or with a major HVT soluble precipitin antigen (anti-common Ag serum) were used as the source of antisera to specify both antigens in these experiments. Absorption of a convalescent serum from HVT-inoculated chicken with IA positive cells, resulted in reduction of their reactivity to IA but not to MA. Differential absorption of the hyperimmune sera by IA positive cells and MA positive cells resulted in reduction of their reactivity to homologous cells but not to heterlogous cells which were used in the absorptions. When the relationship between the levels of anti-IA and anti-MA antibodies was examined by a blocking immunofluorescence test using 38 sera from chickens inoculated with HVT, no correlation was observed (p greater than 0.25). These results provide evidence that MA and IA are antigenically different from each other.

Animals↗
PubMed1980

Relation between the neutralization of herpesvirus of turkeys and the antibody to late-appearing membrane antigen induced by the virus.

The relation between the neutralization of herpesvirus of turkeys HVT) and the antibodies to early appearing membrane antigen (EMA), late appearing membrane antigen (LMA) and intracellular antigen (IA) induced by the virus was examined by blocking of direct immunofluorescence using 38 sera from chickens infected with HVT. Our results provide evidence that anti-LMA is significant in the neutralization of the infectivity (P less than 0.001) since the neutralizing capacity of the serum was related to its blocking index (BI) and not to its anti-EMA titre (BI). Furthermore, the anti-IA titres (BI) of the sera were also related to their neutralizing activity to a lesser extent (P less than 0.025). However, no relationships among any two of the titres of EMA, LMA and IA were observed. The implication of these results of the relationship of LMA to infectious virus particles is discussed.

Animals↗
PubMed1980

Cell fusion activity of bovine leukaemia virus.

Bovine leukaemia virus (BLV) induces two types of cell fusion. Cells inoculated at high multiplicity show cell fusion within 2 h. This type of fusion can be induced by non-infectious virus and does not require protein synthesis for induction. Low m.o.i. also induces cell fusion but this depends on production of infectious virus.

Animals↗