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Biomedical subjects

T Kitamura

Publications and source records attributed to T Kitamura.

At least 865 records · Page 48Linked to original sources
PubMed1976

[Relationship between potential and impedance change associated with excitation of the nerve (author's transl)].

The action potential or the potential change and the impedance change associated with excitation of the sciatic nerve and electric nerve model (ENM, the equivalent circuit of the nerve fiber), were recorded by means of AC bridge supplied of AC of 13 kHz. Records were taken in excitation at the stimulated site by the square current of different duration, exponentially increasing current of different increasing gradient. Records were also taken in propagated excitation, in excitation elicited in refractory period and at the polarized site of the inactive nerve and ENM. By observation of these records, the following results were obtained.1. With respect to potential changes in nerve, two kinds of changes were found, namely, the one was in cause and effect relationship with the impedance change and the other was without relation to impedance change. 2. In the course of the action potential, both kinds of potential changes were found.

Action Potentials↗
PubMed1975

Brain involvement in Whipple's disease: a case report.

A man of 22 with Whipple's disease suffered from a acute febrile state and unconsciousness. Focal inflammatory lesions accompanied by large numbers of peculiar macrophages occurred in thalamus and basal ganglia. The electron microscopic findings conform to previous reports on brain involvement in Whipple's disease.

Adult↗
PubMed1975

Hematogenous cells in experimental Japanese encephalitis.

Four adult mice were injected with 3H-thymidine repeatedly so that in their brains only circulating blood cells were labelled with 3H-thymidine. They then received an intracerebral injection of Japanese encephalitis virus, were sacrified on the 3rd, 4th and 5th day after inoculation: the brains were examined by light and electron microscopic autoradiography. Inflammatory cells appearing in the brain parenchyma and perivascularly in the acute stage of the experimental Japanese encephalitis are derived from circulating mononuclear leukocytes. They assume the shape of "rod cells" and are the main constituents of the "glial nodule" in the brain parenchyma. Their fine structural characteristics are discussed.

Animals↗
PubMed1975

Origin of brain macrophages and the nature of the so-called microglia.

Two aspects of the so-called microglia were studied by silver impregnation and 3H-TdR ARG in light and electron microscopy. (1) So-called microglioblasts are glioblasts differentiated from matrix cells. They are progenitors of the so-called resting microglia as well as of astrocytes and oligodendroglia. (2) Brain macrophages in stab wounds, experimental Japanese encephalitis and retrograde degeneration of the facial nucleus are all found to be of hematogenous origin. Infiltrating hematogenous cells cannot stay permanently in the brain parenchyma unless pathological alterations persist indefinitely.

Animals↗
PubMed1975

[On decrease in spike height of nerve action potential. A comparison between sciatic nerve and ENM (author's transl)].

Employing ENM and a sciatic nerve removed from bullfrog, configuration of decrease of spike under various experimental conditions was studied. The amplitude of the membrane potential change in excitation was also recorded simultaneously with the decrease of spike in ENM (electric nerve model). Both on the nerve and ENM, with decrease of the resting potential, the amplitude of the spike and the amplitude of the change of the membrane potential were decreased. On the nerve and ENM, the decrease in spike amplitudes was induced by an elevation of the niveau and by a lowering of the top. However, the amplitude of the change of membrane potential of ENM was reduced only from the base of the spike due to an elevation of the niveau, with the top remained at a constant level. These decreases of the spike amplitude and the change of the membrane potential in nerve were consistent with that the electric constitution was the same for nerve and ENM, which is the experimental equivalent circut of the nerve fiber devised by the authors.

Action Potentials↗
PubMed1975

[Ultrasonic echography for exploration of parotid tumors].

The authors describe results obtained with ultrasonic echotomography for differential diagnosis of parotid tumours. A picture of the neoplasms is obtained and its benign or malignant nature is ascertained by graded sensitivity investigation.

Adult↗