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Biomedical subjects

H Satoh

Publications and source records attributed to H Satoh.

At least 703 records · Page 39Linked to original sources
PubMed1989

Chromosomal mapping of the mouse IL-4 and human IL-5 genes.

We mapped the mouse interleukin (IL)-4 gene on chromosome 11 by restriction fragment length polymorphism using recombinant inbred mouse strains. The human IL-5 gene was mapped on chromosome 5q 23.3-31.1 by in situ hybridization. Because the granulocyte macrophage colony-stimulating factor (GM-CSF) and IL-3 genes were previously mapped on mouse chromosome 11 (within a 230-kb region) and human chromosome 5, the IL-4 and IL-5 genes are likely to cluster on the same chromosomes with the GM-CSF and IL-3 genes in both species.

Animals↗
PubMed1989

Human anti-endoplasmic reticulum antibodies in sera of patients with halothane-induced hepatitis are directed against a trifluoroacetylated carboxylesterase.

Previous studies have demonstrated that patients with halothane-induced hepatitis have serum antibodies that are directed against novel liver microsomal neoantigens and have suggested that these neoantigens may play an immunopathological role in development of the patients' liver damage. These investigations have further revealed that the antibodies are directed against distinct polypeptide fractions (100 kDa, 76 kDa, 59 kDa, 57 kDa, 54 kDa) that have been covalently modified by the reactive trifluoroacetyl halide metabolite of halothane. In this paper, the trifluoroacetylated (TFA) 59-kDa neoantigen (59-kDa-TFA) recognized by the patients' antibodies was isolated from liver microsomes of halothane-treated rats by chromatography on an immunoaffinity column of anti-TFA IgG. Antibodies were raised against the 59-kDa-TFA protein and were used to purify the native protein from liver microsomes of untreated rats. Based upon its apparent monomeric molecular mass, NH2-terminal amino acid sequence, catalytic activity, and other physical properties, the protein has been identified as a previously characterized microsomal carboxylesterase (EC 3.1.1.1). A similar strategy may be used to purify and characterized neoantigens associated with other drug toxicities that are believed to have an immunopathological basis.

Animals↗
PubMed1989

The possible role of endothelin-1 in the pathogenesis of coronary vasospasm.

We investigated the in vivo vasoconstrictor effects of endothelin-1 (ET-1) on canine coronary arteries and the regulation of ET-1 gene expression with special reference to the pathogenesis of coronary vasospasm. ET-1, administered into the coronary arteries of anesthetized dogs, produced a profound and long-lasting reduction in coronary blood flow with myocardial ischemia. Coronary angiography revealed delayed filling of the distal branches and, in some cases, total occlusion in the epicardial portions of coronary arteries. The coronary vasoconstriction induced by ET-1 subsided after intracoronary administration of nitroglycerin. Pretreatment with the Ca2+-channel antagonist, nitrendipine, suppressed ET-1-induced vasoconstriction. In cultured porcine aortic endothelial cells, ET-1 gene expression was induced by agents related to thrombus formation, such as thrombin and transforming growth factor beta (TGF beta). These findings suggest that ET-1, produced by vascular endothelial cells, may contribute to the regulation of coronary circulation and the pathogenesis of coronary vasospasm with respect to intimal injury and subsequent thrombus formation.

Angiocardiography↗
PubMed1989

An electrophysiological comparison of a novel class Ic antiarrhythmic agent, NIK-244 (ethacizin) and flecainide in canine ventricular muscle.

1. Electrophysiological effects of NIK-244 (ethacizin), a novel class I antiarrhythmic drug, were compared with flecainide in canine ventricular muscle by use of conventional microelectrode techniques. 2. At concentrations of 10(-6) M or higher, NIK-244 depressed the maximum rate of rise of depolarization (Vmax) significantly in a concentration-dependent manner. Also, the resting potential was depolarized at 10(-5) M. NIK-244 did not have any effect on the other action potential parameters or on the effective refractory period. 3. Flecainide significantly decreased Vmax at 3 x 10(-6) M or higher and the resting potential was depolarized at 10(-5) M. Like NIK-244, flecainide did not affect other action potential parameters. 4. NIK-244 and flecainide caused a use-dependent block of Vmax, and the rates of onset of inhibition at 3 Hz stimulation were 0.014 +/- 0.002 AP-1 at 2 x 10(-6) M NIK-244 and 0.021 +/- 0.012 AP-1 at 10(-5) M flecainide. Under the same conditions, the time constants of the recovery from use-dependent block were 27.1 +/- 13.3 s and 12.2 +/- 2.5 s for NIK-244 and flecainide, respectively. 5. These results suggest that NIK-244, like flecainide, should be classified as a slow kinetic drug and as Ic.

Action Potentials↗
PubMed1989

Role of calcium in caffeine-norepinephrine interactions in cardiac Purkinje fibers.

Caffeine-norepinephrine interactions were studied in canine cardiac Purkinje fibers perfused in vitro. Caffeine (0.5-1 mM) or theophylline (0.5-1 mM) increased and then decreased contractile force in the absence and presence of 0.5-10 microM norepinephrine (NE) [in high extracellular calcium concentration ([Ca]o) caffeine only decreases force]. Occasionally, caffeine only decreased force in the presence of NE. In the presence of NE and 12 mM (sometimes even 4 mM) extracellular potassium concentration, caffeine did not decrease force below the precaffeine level. Reciprocally, in 0.5-2 mM caffeine NE increased force, although less than in the absence of caffeine. Even in 9 mM caffeine, NE increased force but slowed the final phase three repolarization of the action potential. Both NE and 8.1 mM [Ca]o increased force, but NE decreased force in the presence of high [Ca]o. In NE and propranolol (or propranolol alone), caffeine only increased force, whereas it had the usual effects in the presence of methoxamine or phenotolamine. In the presence of iodoacetic acid and 2-deoxy-D-glucose, NE caused contracture and caffeine exaggerated it. In contrast, in NE and 2 mM Mn, caffeine only increased force. It is concluded that initially NE diminishes the cytoplasmic calcium overload induced by caffeine (by promoting Ca uptake into the sarcoplasmic reticulum) and subsequently enhances it (by increasing the slow inward current).

Animals↗
PubMed1989

High resolution chromosome banding in the Norway rat, Rattus norvegicus.

High resolution banded chromosomes were prepared from a synchronized culture of rat fibroblasts. A maximum of 457 bands per haploid chromosome set were observed. This represents a two-fold increase when compared to the number of bands visualized in mid-metaphases using standard procedures. By reference to both G- and Q-banded karyotypes, we constructed improved idiograms of rat chromosomes at 300- and 400-band stages, respectively.

Animals↗
PubMed1989

Nilvadipine attenuates ischemic degradation of gerbil brain cytoskeletal proteins.

We have previously demonstrated that transient cerebral ischemia induces marked decreases in concentrations of cytoskeletal proteins and have suggested putative involvement of calpain in the decrease of microtubule-associated protein 2 (MAP2) content. We examine the effect of nilvadipine, a new calcium channel blocker, on protein degradation in gerbil brains after 5 minutes of bilateral carotid artery occlusion and compare this effect with those of nimodipine and nicardipine. By densitometric quantification of the electrophoretically separated soluble proteins, mean +/- SEM MAP2 content in the hippocampus (14.4 +/- 1.8 micrograms/mg protein) was depleted (5.4 +/- 0.5 micrograms/mg, p less than 0.01) 4 days after ischemia; this depletion was significantly inhibited by 1 or 10 mg nilvadipine/kg/day. MAP2 content was also depleted in vitro when normal nonischemic brain extract was incubated with calcium, but this degradation was not inhibited by the calcium channel blockers. Our results suggest that calcium channel blockers do not act directly on calpain but act at the calcium channels of neurons and may suppress activation of the enzyme and attenuate ischemic degradation of cytoskeletal protein. We found nilvadipine to be the most potent drug among those studied, and we believe it could be useful for the treatment of cerebral ischemia.

Animals↗
PubMed1989

Histogenesis of neoformation in the endocrine pancreas of aging horses.

Pancreatic tissue from 20 horses was examined using immunocytochemical techniques. In aged horses, neogenesis of endocrine cells, neoformation, and hyperplasia of islets occurred closely associated with the pancreatic duct; these changes were regarded as nesidioblastosis. In addition, pancreatic fibrosis accompanied by ductal proliferation and endocrine neogenesis was considered a regenerative change. Thus, the origin of neoformation in the endocrine pancreas was in the ductal system, and it is suggested that the pancreatic endocrine cells were of endodermal origin.

Aging↗
PubMed1989

A case of successful coronary artery bypass grafting in a patient with angina pectoris and hypothyroidism.

There is a clinical dilemma in the treatment of patients with hypothyroidism and coronary artery disease; excess thyroid hormone administration may exacerbate anginal symptoms, and yet inadequate thyroid replacement may induce congestive heart failure. A case of successful coronary artery bypass grafting in a patient with angina pectoris and hypothyroidism is described in this paper. A 55 year-old woman with this complication initially received thyroid replacement therapy under strict monitoring. Forty days after the start of the thyroid replacement therapy, serum levels of thyroid hormone had reached the normal range, and then coronary artery bypass grafting was successfully performed. She recovered without any complications, and is now free from chest pain in spite of thyroid replacement therapy.

Angina Pectoris↗
PubMed1989

[Exposure of primary school children and their mothers to nitrogen dioxide in Sapporo City: comparisons of groups clustered by maternal daily behavior and habits].

Exposure of primary school children and their mothers to NO2 was investigated in two schools in the city of Sapporo. One school was located in the city center and another in a suburb of the city. The school children and mothers were requested to put on NO2 filter badges for 24 hours and to record activity during that period. They were also requested to fill out ATS-DLD questionnaires. The surveys were repeated twice, in the summer of 1986 and in the winter 1987, due to possible seasonal variation. Average NO2 exposure levels of both school children and mothers were lower in the summer than the corresponding averages in the winter. The average of the children was lower than that of mothers in both summer and winter. Averages of the children of the city-center school were higher than those of children in the school in the suburb in both summer and winter. These differences were not observed in mothers' averages. To examine the relationship between NO2 exposure levels and maternal daily behavior and habits, the subjects were classified into three clusters by employment status, living area, smoking habits, type of heating appliance, and use of fans during cooking. While average NO2 exposure levels of children were similar among the three clusters, the average of the mothers of the third cluster was the highest among the clusters in either summer or winter. The third cluster was characterized by the highest rate of employment among the clusters, spending less time in their kitchens and not using fans regularly.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗
PubMed1989

Immunocytochemical component of endocrine cells in pancreatic islets of horses.

The endocrine cell components in the pancreatic islets of the following 4 pancreatic regions of the horse were investigated by immunohistochemical methods: lobus pancreatis sinister (left lobe); lobus pancreatis dexter (right lobe); and 2 regions of Corpus pancreatis (body), the duodenal lobe which lies along the cranial duodenal flexure and descending duodenum, and the intermediate lobe which is situated around the portal vein. The islets in the left and intermediate lobes contained a central mass of glucagon cells surrounded by insulin cells, a few somatostatin cells and sporadic pancreatic polypeptide (PP) cells. On the other hand, the islets in the duodenal lobe were small in size compared with the other 3 regions, and were predominant in insulin and pancreatic polypeptide (PP) cells, but almost lacked in glucagon cells. These findings suggested that the duodenal lobe was derived from the ventral pancreatic primordium, and the left and intermediate lobes were originated from the dorsal pancreatic primordium. In the right lobe, the composition and distribution of the islet cells were almost the same as those in the left and intermediate lobes, but there were several lobules containing numerous PP cells as seen in the duodenal lobe.

Animals↗
PubMed1989

Differences in growth of transplantable ascites hepatoma among various lines of Donryu rat.

A total of 48 Donryu rats from 8 colonies of 5 lines were inoculated intravenously with 10(7) cells of the ascites hepatoma strain AH 66. All the conventional rats of the lines D-1 and D-2 died between 9 and 15 days after inoculation with a good growth of implanted tumor cells. On the other hand, SPF rats of the lines A-1, B-1, C and E survived for 60 days showing complete rejection of the implanted tumor cells. A 50% of conventionalized ex-SPF rats of the lines A-2 and B-2, which had been once established as SPF colonies, and thereafter had been "re-conventionalized", rejected the tumor cells. The present observations indicate that the microbial conditions of the animal, e.g. whether the animal is SPF or not, might play an important role in the growth of the implanted ascites hepatoma.

Animals↗
PubMed1989

[Histological study on gingival tissue reattachment after periodontal surgery. Effects of hydroxyapatite ceramic implantation to denuded dentin surfaces in rats].

The purpose of this study was to evaluate histological regeneration of epithelial and connective tissue attachment to the denuded dentin surface after hydroxyapatite ceramic granule (HAP) implantation. HAP (particle size 100-300 microns, burn temperature 900 degrees C) were implanted into dehiscent defects of alveolar bone which eliminated about a 1 x 1 mm area at mesial and palatal sites of the upper 1st molar in 20 male Wistar rats. Subsequently the root cementum was removed totally and dentin was denuded. Same osseous defects were formed but HAP was not implanted at any contralateral site for the purpose of control. Results of 8-week examination using light and electron microscopy were as follows: 1. In the HAP group junctional epithelium was regenerated on the denuded dentin surface 2 weeks after implantation and epithelial down growth was less than at the control site. 2. In the HAP group connective tissue reattachment with new cementum formation was observed at 2 to 4 weeks after implantation, the healing period tended to be shorter than at the control site and the connective tissue reattachment level was located more coronally. 3. In ultrastructural findings collagen fiber bundles attached to the denuded dentin surface had fibers continuing around HAP granules.

Animals↗
PubMed1989

Ultrastructure of the hypophyseal portal vessel in mature rats--SEM and TEM observations.

After chemical digestion of the isolated specimen of the hypophysis of the rat, external surface of the hypophyseal portal vessel in the mature rat was investigated with scanning electron microscope (SEM). The portal vessel lacked smooth muscle fibers, it was accompanied by many pericytes with highly ramifying processes along its whole course. Transmission electron microscopic (TEM) study revealed that the endothelium of this vessel has many fenestrations and channels. These findings suggest that the hypophyseal portal vessel in the mature rat is a capillary sinus with pericytes rather than a vein as suggested previously.

Animals↗