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Biomedical subjects

S Kishi

Publications and source records attributed to S Kishi.

At least 109 records · Page 6Linked to original sources
PubMed1988

Cytochemical demonstration of guanase in human liver using yellow tetrazolium.

Histochemical studies of human guanase (guanine deaminase) have seldom been undertaken, in part because of technical difficulties which result in heavy background staining. We reported a modified procedure for histochemical demonstration of guanase in human tissues involving hydrolytic deamination of the substrate guanine to xanthine via guanase, and then oxidation of xanthine to uric acid, with concomitant reduction of nitrotetrazolium blue (NBT). In this report, we describe a modification of this method for cytochemical demonstration of guanase at the fine structural level using yellow tetrazolium in place of NBT for determination of the intracellular distribution of guanase in human hepatocytes. In the hepatocytes, the reaction products were seen to be concentrated in the nucleus, in mitochondria, cisternae of the smooth and/or rough-surfaced endoplasmic reticulum, and lysosomes. The precise locations of the reaction product in the cisternae of the nuclear envelope, chromosomes, and nucleus could not be determined. However, the reaction products in the mitochondria were clearly seen to be located in the spaces of cristae. This information of the intracellular distribution of guanase in normal hepatocytes will be useful in determining the physiological role of this enzyme and in further studies on diseased hepatocytes including those in non-A non-B hepatitis.

Aminohydrolases↗
PubMed1988

Effect of vitamin B complex on the immunodeficiency produced by surgery of gastric cancer patients.

We studied the effect of vitamin B complex (vitamin B1, B6 and B12 complex) on the immune responsiveness in gastric cancer patients who underwent surgery. The depression of blastogenic responses to both PHA and PWM was observed 2 weeks after surgery in half of the patients treated with Vitamedin but the degree was significantly less than that in the control patients without vitamin B treatment whose lymphocyte responses were depressed. Moreover, the blastogenic responses were induced by vitamin B administration 2 or 4 weeks after surgery in 5 of the 8 stage III-IV patients whose lymphocytes had not responded prior to surgery. Four weeks after surgery, the patients without vitamin B treatment showed only a tendency of recovery of their lymphocyte responses, whereas the recovery of blastogenic responses in the patients treated with vitamin B was significant. Essentially similar results were obtained with skin reactions to PHA and PPD. These results suggest that the administration of vitamin B1, B6 and B12 complex is useful for the protection against and the recovery of immune dysfunction produced by surgery in cancer patients.

Humans↗
PubMed1986

Vitreous cortex remnants at the fovea after spontaneous vitreous detachment.

We performed a scanning electron microscopic observation of the posterior retinal surface of 59 autopsy eyes with spontaneous vitreous detachment. In 26 eyes (44%), there were remnants of the posterior vitreous membrane in the foveal area. These vitreous cortex remnants formed three basic patterns. They appeared either as disc-shaped collagenous membranes covering the fovea, as rings along the foveal margin, or forming a structure that resembles a cyst. Each of these patterns seemed to have a counterpart to various known clinical situations. These findings imply that remnants of the vitreous cortex membrane frequently remain attached to the fovea after apparent complete posterior vitreous detachment. The observed features would provide morphological basis for the interpretation of several clinical conditions that take place along the vitreoretinal interface at the fovea.

Autopsy↗
PubMed1986

Epivascular glia and paravascular holes in normal human retina.

We examined the retinal surface of 28 autopsy eyes by scanning electron microscopy (SEM). Glialike cells or their processes, arranged in rows, were observed along retinal vessels in 22 eyes. Additionally, there were clusters of glialike cells over retinal vessels in 8 eyes. These proliferations ranged from focal to extensive ones, the latter resulting in distinct preretinal membranes. Focal defects of the superficial retina along the vessel were noted in 6 of 28 eyes. Transmission electron microscopic study in 2 surgically enucleated eyes with normal retinae revealed epivascular retinal degeneration and thinning of Müller cells. Glial processes appeared to be covering the defect of the internal limiting membrane and some projections of these cells continued inwards. These findings were consistent with the SEM findings of epivascular glialike structure. Our conclusions are that epivascular glialike structures and paravascular surface defects appear as a common finding in normal senile eyes, and that occasionally membranous formations arise from the epivascular area.

Adult↗
PubMed1986

An elevated type of gastric ulcer scar in patients treated with cimetidine.

An elevated type of gastric ulcer scar (EUS) (A) was noted in 8 out of 227 ulcer patients treated with cimetidine. These were compared with 15 patients with EUS (B), not treated with cimetidine and the etiology of the lesion was discussed. The incidence of EUS (3.5%) and the average age of the patients were higher (61 years) in the A group than in the B group. The scar was seen all over the stomach in the A group. The period from detection of gastric ulcer to confirmation of EUS averaged 4 weeks, and there was no difference between the two groups. No difference was seen in the histological findings of elevated lesions either. In the A group, it appears that EUS was induced by rapid tissue regeneration due to the strong anti-ulcer effect of cimetidine in ulcer lesions, since it was noted in the regions where it had previously been considered unlikely to occur.

Adolescent↗
PubMed1985

Fundus lesions in malignant hypertension. I. A pathologic study of experimental hypertensive choroidopathy.

Experimental hypertensive choroidopathy was studied in 29 eyes from 15 monkeys in which accelerated renovascular systemic hypertension developed after a modified Goldblatt procedure. We followed up the animals from five days to 21 months to examine clinically and histopathologically the spectrum of the pathologic process. The pathologic features of hypertensive choroidopathy in our animals may be categorized into three phases: (1) Acute ischemic phase: The initial change in the choroidal vasculature was constriction of arterioles, which leads to focal necrosis of the choriocapillaris and the retinal pigment epithelium and focal subretinal exudate. (2) Chronic occlusive phase: Occlusive changes involving arteries, arterioles, and choriocapillaris occurred later. (3) Chronic reparative phase: With time, recanalization took place at all levels of the choroidal vasculature. The subretinal fluid was reabsorbed, leaving diffuse patchy depigmentation of the retinal pigment epithelium, which followed lobular arrangement of the choriocapillaris. Arteriolization of the choriocapillaris developed; this seems to be a defense mechanism to withstand the elevated systemic blood pressure.

Animals↗
PubMed1985

Fundus lesions in malignant hypertension. II. A pathologic study of experimental hypertensive optic neuropathy.

Accelerated renovascular hypertension produces optic nerve changes ranging from optic disc edema to optic atrophy. To elucidate the pathogenesis of hypertensive optic neuropathy, the optic nerves from 12 monkeys (23 eyes) with accelerated renovascular systemic hypertension were studied by electron and light microscopy. Within 21 months, the animals demonstrated the entire spectrum of pathologic changes. In the optic nerves with optic disc edema, the prelaminar optic nerve exhibited vasoconstriction with subsequent axonal hydropic swelling, axolemma disruption, and glial swelling. In retrolaminar myelinated optic nerve, vasoconstriction was more severe, with endothelial swelling and pericytic degeneration resulting in intramyelinic vacuoles and glial swelling. Optic disc edema appeared to result from axonal hydropic swelling secondary to ischemic infarct, followed by loss of axons and gliosis in the prelaminar optic nerve. The retrolaminar myelinated nerve showed prominent microglial reaction and eventual atrophy of axons and glia. Ischemia seemed to play a major role in hypertensive optic neuropathy, which represents anterior ischemic optic neuropathy.

Animals↗
PubMed1984

Postprandial release of neurotensin-like immunoreactivity and its mechanism.

The effects of various ingested materials on plasma neurotensin-like immunoreactivity (NTLI) in humans were investigated using a newly developed, specific radioimmunoassay. Plasma NTLI was determined after its extraction with acid/acetone (recovery 77 +/- 4%). The intraassay and interassay coefficients of variation were 3.6% and 8.9%, respectively. The plasma concentration of human NTLI in normal subjects was 5.6 +/- 2.9 pmol/l and showed no significant sex difference. Ingestion of a test meal (150 g of Campbell's condensed meat soup) caused a biphasic rise in plasma NTLI from a basal level of 5.7 +/- 1.0 pmol/l to 10.8 +/- 1.2 pmol/l after 30 min and 9.6 +/- 1.1 pmol/l after 120 min. Ingestion of 5.5 g fat resulted in a biphasic rise in plasma NTLI from a basal level of 4.8 +/- 0.3 pmol/l to 8.9 +/- 0.3 pmol/l after 15 min and 11.9 +/- 0.4 pmol/l after 90 min. When 100-150 mg of ileal mucosa was perfused with a solution of 2 mEq/l fatty acids, 1 mM or 5 mM sodium taurocholate or 154 mM sodium bicarbonate (NaHCO3), the release of NTLI from the mucosa into the perfusate was 2.3-fold, 4.3-fold and 7.5-fold, respectively, over the base level. These results indicate that NTLI release is stimulated by ingestions of meat soup and fat and that NTLI present in the human ileum is released by the direct actions of solutions of fatty acid, sodium taurocholate, and NaHCO3 on the ileal mucosa. These findings strongly suggest that neurotensin (NT) has a physiological role in gut physiology.

Adult↗