Search PubMed⌕ Search

Biomedical subjects

H Fukuyama

Publications and source records attributed to H Fukuyama.

At least 235 records · Page 13Linked to original sources
PubMed1986

Localization of monoamine oxidase (MAO) in the rat peripheral nervous system--existence of MAO-containing unmyelinated axons.

Using a new coupled peroxidation method modified by adding nickel ammonium sulfate, we demonstrated the localization of monoamine oxidase (MAO) in the rat peripheral nervous system. MAO was localized in the endothelial cells of endoneurial vessels, in Schwann cell cytoplasm encircling myelinated axons, and in some unmyelinated axons. The morphometric ratio of these MAO-containing axons to the total unmyelinated axons was 10-13%. These MAO-containing unmyelinated axons were assumed to coincide with postganglionic sympathetic noradrenergic ones passing in the sciatic nerve. Histochemical MAO staining may be utilized to identify the postganglionic sympathetic nerves in normal and pathological conditions at the electron microscopic level in particular.

Adrenergic Fibers↗
PubMed1986

Periodic acid-Schiff (PAS)-positive, granular structures increase in the brain of senescence accelerated mouse (SAM).

Abnormal granular structures, which stained positively with periodic acid-Schiff (PAS-positive granular structures; PGS), were observed in the brain of senescence accelerated mouse (SAM). They were small, round to ovoid, homogeneous structures measuring up to 5 microns in diameter and usually grouped in clusters. PGS were localized in the hippocampus, piriform cortices, olfactory tubercle, nucleus of the trapezoid body, and cerebellar cortices. Quantitative analysis revealed that PGS remarkably increased in the hippocampus of SAM-P/8, a substrain of SAM, with advancing age, although a few PGS also appeared in the aged control mice, SAM-R/1 and DDD. Their histochemical nature, morphological features and distribution pattern were different from those of corpora amylacea and other similar bodies. A close anatomical relationship between PGS and glial fibrillary acidic protein-positive astrocytes was inferred from immunohistochemical studies. PGS is considered to be one of the morphological manifestations of senescence in mice brains, and are found to occur more numerously in the brains of learning or memory deficit mice, SAM-P/8.

Aging↗
PubMed1986

Effects of propranolol on myocardial damage resulting from coronary artery occlusion followed by reperfusion.

To evaluate the effects of propranolol on myocardial metabolism after coronary reperfusion, serial measurements of myocardial creatine kinase (CK) and calcium (Ca) contents and CK and lactic acid (LA) concentrations in coronary sinus blood were carried out in 33 open-chest dogs. The left anterior descending coronary artery was occluded for 60 minutes and was then reopened. Twelve of the dogs were given propranolol before occlusion. Reperfusion for 30 minutes in dogs with and without propranolol pretreatment resulted in reduced myocardial CK in the ischemic region and rapidly elevated plasma CK and LA. However, when compared with the control group, the propranolol-treated group showed smaller changes in myocardial CK and plasma LA. Myocardial Ca in the ischemic region was significantly higher than that in the nonischemic region in the control group, but not in the propranolol-treated group. It was concluded that propranolol was protective against myocardial damage resulting from coronary occlusion followed by reperfusion.

Animals↗
PubMed1986

Thalamic tumours invading the brain stem produce crossed cerebellar diaschisis demonstrated by PET.

Two cases of thalamic tumour, spreading through the midbrain into the pons ventrolaterally, showed suppression of cerebellar blood flow on the opposite side to the tumour, and also showed reduction of blood flow in the pons on the side of the tumour in positron emission tomographic studies. The pathophysiological mechanism of crossed cerebellar diaschisis may be due to functional suppression of the pontine nuclei by destruction of descending fibres from the cerebral cortex.

Adult↗
PubMed1985

Serial determinations of serum enzymes following aorta-coronary bypass surgery and acute myocardial infarction.

Serial determinations of serum creatine kinase (CK), cardio-specific isoenzyme of CK (CK-MB), glutamic oxaloacetic transaminase (GOT) and alpha-hydroxybutylate dehydrogenase (HBD) were made in 29 consecutive patients undergoing aorta-coronary (AC) bypass grafting, and the results were compared with those in 31 patients with acute myocardial infarction (AMI). Postoperatively, all patients had an uneventful postoperative course and there was no evidence of AMI. The time course of enzyme activity following surgery was characterized by 1) shortening of peak activity time of all enzymes except CK, 2) rapid disappearance of CK-MB, 3) prolonged normalization of GOT and HBD. Peak activities of CK, CK-MB, GOT and HBD in AC bypass patients were 801 +/- 77, 46 +/- 6, 100 +/- 9 and 718 +/- 32 IU (mean +/- SEM), respectively, which were equivalent to 46%, 12%, 22% and 47% of those in AMI. The degree of postoperative CK-MB elevation was influenced by the duration of the operation and the extracorporeal circulation, and the number of grafts bypassed. The peak CK-MB activity did not correlate with the CK peak. The ratio of CK-MB to CK was much smaller in AC bypass than in AMI (6.5 +/- 1.8 vs. 20.1 +/- 1.4%). It was concluded that serum enzyme elevations after AC bypass surgery largely reflected enzyme release from the skeletal muscle rather than the myocardium.

Adult↗
PubMed1985

Active site of intestinal gamma-glutamyltransferase faces luminal side of brush border membrane.

Purified gamma-glutamyltransferase from hog small intestine was competitively inhibited by glutathione in vitro when L-gamma-glutamyl-p-nitroanilide was used as a substrate. An S-acetyldextran derivative of glutathione inhibited the enzyme as well as glutathione, although dextran had no inhibitory effect. gamma-Glutamyltransferase in the rat small intestine could utilize in situ L-gamma-glutamyl-p-nitroanilide circulated in the lumen, and was inhibited by the impermeable derivative of glutathione which was on the luminal side. These data suggested that the active site of intestinal gamma-glutamyltransferase faced the luminal side of the brush border membrane.

Aniline Compounds↗
PubMed1983

Krypton-81m single photon emission tomography and the collateral circulation in carotid occlusion: the role of the circle of Willis and leptomeningeal anastomosis.

Cerebral perfusion images were investigated in patients with carotid artery occlusion, using single photon emission computed tomography with the infusion of krypton-81m into the internal, common carotid and vertebral arteries. The contribution of the circle of Willis and cerebral cortical anastomoses to the maintenance of adequate blood supply into the involved hemisphere was analysed. It was concluded that the cerebral perfusion image is superior to angiography in evaluating collateral circulation, and in the case of carotid occlusion, the circle of Willis is important in preventing infarction in the territory of the perforating arteries, while the cerebral cortex mainly receives its blood supply through the cortical leptomeningeal anastomoses, illustrating the major role of the leptomeningeal anastomosis as a collateral channel.

Adult↗
PubMed1983

Superimposition of Krypton-81m single photon emission CT and X-ray CT images for cerebral blood flow evaluation.

Selective arteriographic infusion of krypton-81m was used to obtain cerebral single photon emission computed tomograms. These were then superimposed on X-ray computed tomograms to assess topographically the perfusion of the entire brain. This method enhances the detecting capability for abnormal perfusion areas and has been used in 21 patients with various brain diseases.

Carotid Artery Thrombosis↗
PubMed1982

Radioisotope cisternography in acute viral encephalitis. A reappraisal.

Five cases of presumed acute viral encephalitis with convulsions were examined with radioisotope (RI) cisternography six and 24 hours after an intrathecal injection of 1 mCi of pentetic acid labeled with either ytterbium 169 or indium 111. All cases showed abnormalities with this study. The "cold" areas observed with RI cisternography were well correlated with abnormal foci on the EEG. Although the findings are nonspecific, the CSF dynamics and patency of the subarachnoid space are easily examined by RI cisternography without appreciable complications. It is a useful supplementary diagnostic method to depict the extent of lobar abnormalities of cerebral cortex, particularly at an early stage, that either narrow or obliterate subarachnoid space and CSF pathways.

Acute Disease↗