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Biomedical subjects

M Shirahama

Publications and source records attributed to M Shirahama.

At least 55 records · Page 3Linked to original sources
PubMed1987

Kupffer cells modulate natural killer cell activity in vitro by producing prostaglandins.

The effect of Kupffer cells on natural killer (NK) cell-mediated cytotoxicity was examined. Kupffer cells prepared from rat liver suppressed NK activity against K562 cells and other tumor cell lines through a soluble factor secreted into the culture supernatant. When human peripheral blood mononuclear cells were incubated with the Kupffer cell-culture supernatant, a significant reduction of the cytotoxic activity was observed in the 6-hr chromium-release assay. This activity was dose dependent and was evident at various effector/target cell ratios. Lipopolysaccharide stimulated generation of the suppressive factor released from Kupffer cells in a dose-dependent manner. Suppression of the NK activity was observed when the Kupffer cell-culture supernatant was present in the assay system, whereas pretreatment of effector/target cells with the supernatant had minimal inhibitory effects. Autologous monocytes in human peripheral mononuclear cells were not related to this suppression. The suppressive factor in the fraction had a molecular weight below 10,000. Indomethacin, an inhibitor of prostaglandin synthesis, ameliorated the suppressive effects. These results suggest that Kupffer cells may modulate NK activity by producing PGs (E1, E2, and F2 alpha).

Animals↗
PubMed1987

Recovery after radiotherapy from severe interstitial pneumonia due to paraquat poisoning.

A 51-year-old man was admitted 3 hours after ingesting approximately 50 ml of mixture of paraquat and organophosphate insecticide. His arterial oxygen pressure fell progressively to 44.6 mmHg. Diagnosed was paraquat-induced interstitial pneumonia. No improvement was observed after treatment with corticosteroid. The pneumonia, however, resolved after irradiation of both lungs and arterial oxygen pressure showed marked improvement. Radiotherapy to the lungs should be considered only in patients who showed progressive deterioration of respiratory function.

Combined Modality Therapy↗
PubMed1982

[Electrophysiological atlas of human thalamus and adjacent structures.--Microcomputer assisted mapping of neurophysiological data and its application to stereotaxic surgery].

During stereotaxic surgery anatomical structures and their extent on trajectories were identified by neural noise (field potential) obtained by semi-microelectrode technique. Locations of anatomical structures (the white mater, caudate nucleus, thalamus, subthalamic field and nuclei in the subthalamic field) were fed into microcomputer (NEC PC-8001) as 3 dimensional correlates and stored in minifloppy disc system (NEC PC-8031). Data with satisfactory recordings from 48 trajectories from 30 patients (18 parkinsonism, 5 central pain, 7 others) entered this study. Microcomputer was so programmed that locations of the trajectories and electrophysiologically identified anatomical structures at that location in various coronal, sagittal and horizontal planes were displayed. Accumulation of this display from various groups of patients automatically created electrophysiological atlas. For comparison of thus created electrophysiological atlas with anatomical atlas display was made on various sections of the Schaltenbrand and Bailey's Atlas which were also stored in the mimifloppy disc system. Electrophysiological topography of the thalamus and adjacent structures was reasonably similar to anatomical topography with minor, but significant individual variations. In most cases the ventral border of the thalamus was located in the close vicinity of CA-CP line, however, in some cases the thalamus was located deep into the subthalamic field. This was thought to be due to the difficulty in identifying the ventral border of the thalamus by this technique and in such occasions other neurophysiological method for identifying the ventral border of the thalamus, i.e., thalamocortical evoked potential and other stimulation technique, were necessary. Medial aspect of the V. im. nucleus emitted neural noise of different characteristics which in current program was recognized as the subthalamic field. This implies that the medial and lateral aspects of the V. im. nucleus are cytoarchitecturally different and that it is possible to differentiate the medial and lateral aspects of the V. im. nucleus by this technique. The lateral thalamic border, i.e., thalamocapsular border, also showed relatively wide range of individual variations. When various parameters including age, sex, diagnosis and width of the 3rd ventricles were examined for possible cause of these variations, a tendency was noted that the thalamocapsular border was medially placed when the width of the 3rd ventricle was small. In this system it is possible to display sequentially electrophysiologically identified structures along any trajectory. This display method, which was called "tract study," was very usefull for comprehensive understanding of location of trajectory in relation to individually varying anatomical structures...

Adolescent↗
PubMed1981

[Neurogenic pulmonary edema following severe head injury--case report (author's transl)].

A case of severe head injury associated with fulminant pulmonary edema considered as neurogenic which developed within short time after the injury was presented. A five-year-old boy who had no previous history of cardiopulmonary disease was struck on his right frontal region by car accident at 15.30 PM on July 5 of 1979. Immediately after the impact he lost his consciousness and subsequently transferred to a local hospital where bilateral dilated pupil and flaccid paralysis of the limbs were noted. On transmission of the patient to Omuta City Hospital 30 minutes after the injury, massive foamy fluid was discharged from the tracheal tube. On admission, he was comatous, with bilateral dilated and fixed pupils and flaccid paralysis of the limbs. There was no retinal bleeding. He showed ataxic respiration with severe stridor and massive discharge of foamy fluid pinkish in colour from the trachea characteristic in pulmonary edema was significant. Chest x-ray film demonstrated perihilar densities suggesting pulmonary edema. CT scan showed extremely small ventricle on both sides without manifestations of intracranial hematomas or cerebral contusion. With an intensive medical treatments including corticosteroids, alkalizing agents and alpha-blocker were administered under controlled respiration, the discharge of edema fluid was gradually decreased and the findings on blood gases were also improved. However neurological signs were aggravated and he died 8 hours after the injury. Central venous pressure was maintained at the level between 8 to 10 cm. From these clinical findings the pulmonary edema was concluded as neurogenic. Direct or indirect injury to the hypothalamic efferent pathway at the level of lower brain stem seemed to be important as the cause of neurogenic pulmonary edema in this case. The possible pathophysiology of neurogenic pulmonary edema associated with brain stem injury and intracranial hypertension was discussed with other related literature.

Brain Concussion↗