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Biomedical subjects

H Nishimura

Publications and source records attributed to H Nishimura.

At least 577 records · Page 32Linked to original sources
PubMed1990

Human malignant melanoma cell line (HMV-II) for isolation of influenza C and parainfluenza viruses.

HMV-II, a human malignant melanoma cell line, was compared with other cell lines (MDCK, Vero, and LLC-MK2) and primary cultures of monkey kidney (PMK) cells for the isolation and quantification of influenza and parainfluenza viruses. HMV-II cells were superior to MDCK and LLC-MK2 cells in quantification of the influenza C virus and were used successfully in the isolation of the virus from clinical specimens. The HMV-II cell line was also more sensitive for isolating parainfluenza viruses from clinical specimens than were Vero and PMK cells; there was, however, no significant difference in the quantification of the viruses among these cultures. As far as influenza A and B viruses were concerned, the HMV-II cell line was significantly less sensitive than MDCK cells, and no virus was isolated from clinical specimens with HMV-II cells. Thus, HMV-II cells are useful for the isolation of influenza C and parainfluenza viruses as an alternative to embryonated hen's eggs and PMK cells.

Animals↗
PubMed1990

Changes in insulin receptor kinase with aging in rat skeletal muscle and liver.

To see if insulin receptor kinase activity alters with aging, the activity of wheat germ agglutinin-purified receptor preparations from liver and skeletal muscle was compared in 2-, 4-, 10-, and 20-mo-old rats. Basal and insulin-stimulated autophosphorylation of liver insulin receptor and its kinase activities toward histone 2b and poly(Glu4Tyr1) did not alter with aging. On the other hand, the muscle insulin receptor showed different results. Insulin-stimulated increases of autophosphorylation and the kinase activity toward histone 2b above basal were comparable in the four groups. However, insulin-stimulated phosphorylation of poly(Glu4Tyr1) was decreased in 20-mo-old rats compared with 10- and 4-mo-old rats. These results indicate that insulin receptor kinase activity could vary under certain conditions, depending on the substrate used to measure the activity. It is concluded that insulin receptor kinase activity does not change markedly during the process of aging, although subtle changes seem to exist.

Adenosine Triphosphate↗
PubMed1990

Endothelium-dependent L-Arg- and L-NMMA-sensitive mechanisms regulate tone of brain microvessels.

Pial arterioles on the surface of the mouse brain were observed via television microscopy and measured with an image-splitting technique. The vessels were dilated by L-arginine (L-Arg) in concentrations as low as 10(-5) M and were constricted in dose-dependent manner by NG-monomethyl-L-arginine (L-NMMA). Both the dilation and the constriction were abolished by endothelial damage. This damage was produced over a short segment of endothelium by a well-established technique that involves exposing the endothelium to a helium-neon laser in the presence of intravascular Evans blue dye. In arterioles that were responsive to 10(-5) M L-Arg, five other L-amino acids, also at 10(-5) M, failed to have any effect. The data provide direct evidence for the endothelium-dependent nature of the responses to L-Arg and L-NMMA in vivo in a defined segment of the cerebral vasculature. L-NMMA inhibited dilation by either L-Arg or acetylcholine. The data are consistent with data from in vitro studies and from studies demonstrating that L-NMMA acutely raises blood pressure. From all these earlier studies it has been hypothesized that there is a continuously acting, endothelium-dependent, L-Arg-dependent, and L-NMMA-inhibitable mechanism tending to relax blood vessels. The mediator of this mechanism is thought to be the endothelium-dependent relaxing factor for acetylcholine. Our data suggest that this mechanism is acting in the resistance vessels of the brain in vivo.

Acetylcholine↗
PubMed1990

Angiotensin II binding sites in aortic endothelium of domestic fowl.

In domestic fowl, angiotensin II (ANG II) produces a unique vasodepressor response in vivo and endothelium-dependent relaxation of aortic rings in vitro that appear to be a direct effect on vascular smooth muscle mediated through vascular angiotensin receptors. To explore the possible role of the endothelium in ANG II-induced vasodilation, ANG II binding to aortic membrane fractions and intact endothelium and prostaglandin (PG) production were examined in fowl aortas. 125I-[Ile5]ANG II binding by endothelium-intact aortic membrane fractions was consistently higher than binding by identically prepared endothelium-deleted membrane fractions at virtually all concentrations of ligand (10 pM-0.20 microM). Incubation of intact aortic rings with 125I-[Ile5]ANG II (0.50 nM) resulted in specific endothelial binding that increased linearly with time from 5.5 +/- 1.7 (SE) fmol/mg protein at 5 min to 13.7 +/- 1.8 at 30 min. Endothelial ANG II binding increased linearly with the dose of ligand, from 2.7 +/- 0.3 fmol/mg protein at 0.1 nM to 21.0 +/- 2.2 at 1.0 nM. Specific ANG II binding to aortic endothelium was competitively displaced 73 +/- 11% by unlabeled ANG II (0.1 microM) but not by bradykinin (0.1 microM). Incubation of intact aortic rings with [14C]arachidonic acid resulted in the formation of radioactive metabolites that comigrated in thin-layer chromatography with authentic PGE2 but not with 6-keto-PGF1 alpha. PGE2 production by aortic rings (44.4 +/- 4.5 ng.mg dry tissue-1.h-1) was not stimulated by addition of ANG II. These results suggest that specific receptors for ANG II exist in fowl aortic endothelium and that PGs are not involved in ANG II-induced vasodilation of the fowl aorta.

Angiotensin II↗
PubMed1990

Growth and differentiation of fetal rat limb buds transplanted in athymic (nude) mice.

Limb buds of day 14 rat fetuses were cut into pieces and transplanted into the subcutaneous tissue of athymic (nude) mice. In day 14 fetal limbs, mesenchymal cells have begun to condense to form cartilaginous anlage, but no cartilage has been formed. Within 7 days after grafting, masses of hyaline cartilage developed. Numerous osteoblasts appeared, and new bone formation began by 14 days. By 20 days, osteoclasts appeared, and the formation of bone trabeculae and marrow cavities progressed. The cytological characteristics of chondrocytes, osteoblasts and osteoclasts were essentially the same as those seen in vivo. Many grafts developed into long bones, having the diaphysis and epiphysis. The mode of chondrogenesis and osteogenesis in the grafts was histologically similar to the corresponding process in vivo, although the differentiation was slower in the grafted limbs. Since the grafted limb buds showed remarkable growth and tissue differentiation for at least several weeks, this heterotransplantation system would be of potential use for the study of bone formation and resorption as well as for developmental toxicological studies.

Animals↗
PubMed1990

Activation of kallikrein-kinin system in human plasma with purified serine protease from Dermatophagoides farinae.

An aqueous extract from a mite culture, of Dermatophagoides farinae, activated prekallikrein to kallikrein in normal plasma. Crude protein preparation, obtained by ammonium sulfate precipitation (95% saturation) from the extract, exhibited high activity (0.81 units/mg protein) towards a synthetic substrate of coagulation factor XIIa, Boc-Gln-Gly-Arg-MCA, and had also activity to form kallikrein in human plasma deficient in coagulation factor XII. Treatment of the protein preparation with phenylmethylsulfonyl fluoride (PMSF), an inhibitor of serine enzyme, gave rise to inactivation of both activities. Thus, the serine protease specific for Boc-Gln-Gly-Arg-MCA in mite cultures of D. farinae was purified by ammonium sulfate precipitation and chromatographies on p-aminobenzamidine-sepharose CL-4B, DEAE-Toyopearl 650M, Sephadex G-75 superfine and Sephacryl S-200. The purified protease was homogeneous electrophoretically, and its molecular weight was estimated to be 30,000. The optimum pH and temperature were around 7.5 and 50 degrees C, respectively. The specific activity was 36 units/mg protein at pH 7.4 and 37 degrees C. The activity was completely inhibited by PMSF. The serine protease had the activity to activate the kallikrein-kinin system in normal human plasma.

Animals↗
PubMed1990

Leukotriene constriction of mouse pial arterioles in vivo is endothelium-dependent and receptor-mediated.

The diameters of pial arterioles of mice were monitored in vivo with an image-splitting technique and television microscopy. Concentrations of leukotriene C4 as low as 10(-7) M constricted the arterioles. The leukotriene C4-D4 receptor blocker ICI 198615 (10(-8) M) inhibited the response. Endothelial injury by helium-neon laser/Evans blue technique eliminated the constriction and unmasked a slight but consistent relaxation that was not inhibited by 10(-8) M ICI 198615. Since leukotrienes are produced by the brain and enter the cerebrospinal fluid in ischemia, head trauma, and subarachnoid hemorrhage, the possibility that leukotrienes C4 and D4 contribute to decreases in cerebral blood flow during these conditions should be considered. However, the present data makes such a possibility far less likely because the endothelium is frequently injured in these conditions, and therefore the ability of leukotrienes to constrict vessels would be severely curtailed.

Animals↗
PubMed1990

Localization of metallothionein in the genital organs of the male rat.

We studied the immunohistological localization of metallothionein (MT), a low molecular weight metal binding protein, in male rat genital organs (testis, epididymis, ejaculatory duct, seminal vesicle, coagulating gland, and prostate) by use of the avidin-biotin-peroxidase complex method. MT concentrations in testis, seminal vesicle, and prostate ranged from 15-30 micrograms/g tissue. In testis, seminiferous tubules with mature spermatozoa exhibited weak MT staining, whereas the tubules containing differentiating spermatogenic cells but not containing spermatozoa showed strong MT staining. No MT immunostaining was observed in Leydig cells. In growing rat testes, the pattern of MT immunostaining was found to change with development: MT was found in supporting cells only on Day 7, spermatogonia adjacent to basement membrane on Day 14, and spermatocytes localized in the central part of the tubules on Day 21. Strong MT immunostaining in the basal cells was a common feature in other genital tissues, except the ductus efferentes. In prostate, the strongest MT staining was found in the lateral lobe, and MT was localized in apocrine secretions in the dorsal lobe. The present results suggest a close association of MT with cell proliferation and differentiation, as well as possible involvement of MT in supply or storage of zinc ions.

Animals↗
PubMed1990

Inhibitors of skin-tumor promotion. VIII. Inhibitory effects of euglobals and their related compounds on Epstein-Barr virus activation. (1).

Twelve euglobals from Eucalyptus globulus and their twenty-six related compounds were examined for their inhibitory effects on Epstein-Barr virus activation by a short-term in vitro assay. The results showed that most of the euglobals having monoterpene structures, and euglobal-III (8) had strong inhibitory activity. Grandinol (18), homograndinols (19 and 20), and compounds 26, 27, 28, and 32 showed stronger inhibitory effects. Based on the results, the structural requirements for the activity of these compounds were discussed.

Antineoplastic Agents, Phytogenic↗
PubMed1990

Concentrations of ampicillin in human serum and mixed saliva following a single oral administration of lenampicillin, and relationship between serum and mixed saliva concentrations.

The concentrations of ampicillin in serum and mixed saliva after a single oral administration of lenampicillin (500 mg) were determined by the paper disc method. The samples of serum and mixed saliva were obtained at 1, 2, 3 and 4 h after administration. The highest concentrations of ampicillin in serum and mixed saliva occurred 1 h after administration of lenampicillin, and were 11.55 and 0.060 micrograms/ml, respectively. A significant correlation coefficient between the concentrations of ampicillin in serum and mixed saliva, r = 0.71, P less than 0.001, was found.

Administration, Oral↗
PubMed1990

Alterations in gap junctions of human endometrial epithelial cells during normal menstrual cycle--freeze-fracture electron microscopic study.

Gap junctions between human endometrial epithelial cells were studied at various phases of the normal menstrual cycle by freeze-fracture electron microscopy. The junctions changed in number and size according to the phases of the menstrual cycle. Only small and few gap junctions were found in the early proliferative phase. In the early secretory phase the junctions were larger and found more often in the earlier phase. In the late secretory phase the junctions were much smaller than in the early secretory phase. The cyclical changes of the junctions may have a role in controlling the proliferation and differentiation of the endometrial epithelium.

Endometrium↗
PubMed1990

Periventricular lucencies on computed tomography in multiple cerebral infarcts: correlation with cerebral blood flow measurements.

Forty-nine patients with multiple cerebral infarcts with a mean age of 70.2 years were studied to elucidate the effect of periventricular lucencies (PVLs) on cerebral blood flow (CBF). Patients with multiple cerebral infarcts showed significantly lower mean cortical blood flow (F1) values compared to 15 age-matched normal subjects (p less than .01). The mean F1 values were most significantly decreased in severe group of PVLs and moderately decreased in moderate and mild groups (p less than .05 between severe and mild groups); however, no significant differences in mean F1 values were found between severe and moderate groups. Demented patients showed significantly lower F1 values compared to nondemented patients (p less than .001) and normal subjects (p less than .001). There was no significant difference in the degree of PVL between demented and nondemented groups. As well, the mean F1 values were not significantly correlated with either the number of infarcts or ventricular dilatation. These results suggest that PVLs on CT (especially in severe cases of PVLs) may have some role in the reduction of cortical blood flow in patients with multiple cerebral infarcts.

Aged↗
PubMed1990

[Establishment of permanent atrial fibrillation and time course of the amplitude of the f wave].

Atrial fibrillation is one of the arrhythmias that increase with increasing age. In this study we compared transition intervals from sinus rhythm to permanent atrial fibrillation and the time course of the f wave amplitude immediately after the transition between 32 younger (less than 65 years) and 44 elderly patients (greater than or equal to 65 years) in whom transition from sinus rhythm to permanent atrial fibrillation was confirmed on serial ECG recordings. Each group was classified into three categories according their underlying diseases: hypertensive heart disease, valvular disease, and lone atrial fibrillation. In patients with hypertensive heart disease or lone atrial fibrillation, there was no significant difference in the transition intervals between the younger and the elderly groups. In both groups the transition intervals were significantly (p less than 0.05) longer in patients with lone atrial fibrillation than those in patients with hypertensive heart disease (44.6 vs. 12.5 months in younger and 26.8 vs. 12.9 months in elderly). A significant positive correlation (r = 0.58, p less than 0.01) was observed between the final P wave and the initial f wave amplitude on establishment of permanent atrial fibrillation in all patients. In the younger group, the initial f wave amplitude of patients with valvular disease (0.27 +/- 0.04 mV, mean +/- SE) was significantly larger than those of patients with hypertensive heart disease (0.15 +/- 0.03 mV, p less than 0.05) and of patients with lone atrial fibrillation (0.16 +/- 0.01 mV, p less than 0.05). The f wave amplitude of valvular disease was significantly decreased after 1 year (0.22 +/- 0.03 mV, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Histomorphological studies of Krukenberg tumor on early ovarian metastatic lesion].

In ten cases of "early" Krukenberg tumor with only slight swelling of the ovary, histomorphological studies were performed to clarify the process of the formation of Krukenberg tumor. 1) The histological features of early metastatic lesion were classified into 3 types; lymph vessel permeation only, solid alveolar structure, and diffuse infiltration type. 2) Lymph vessel permeation in the ovarian hilum was observed in all cases. 3) In the diffuse infiltration type, signet-ring cells extended diffusely and radially via the lymph vessels, and, in the periphery, tumor cells leaked from the lymph vessels, infiltrating the stroma. At this stage, the response of ovarian stroma was slight, and signet-ring cells were present more abundantly in the vicinity of the infiltrated area. 4) In the solid alveolar type, the stroma was interposed in these lesions. 5) CEA staining revealed many CEA positive tumor cells in the proliferated stroma in which tumor cells failed to be detected. In summary, tumor cells infiltrate via the lymph vessels and leak into the stroma. Following the destruction of signet-ring cells, the mucus leaks into the stroma and it produces stromal edema and proliferation, eventually leading to a swollen ovary.

Adult↗
PubMed1990

Binding activity and autophosphorylation of the insulin receptor from patients with myotonic dystrophy.

To clarify a mechanism of insulin resistance associated with myotonic dystrophy, we studied the insulin receptor by using three different types of cells--circulating erythrocytes, cultured skin fibroblasts, and Epstein-Barr virus(EBV)-transformed lymphocytes. In myotonic dystrophy, insulin binding to erythrocytes and fibroblasts was significantly decreased as a result of a reduction of the binding affinity. Insulin binding to EBV-transformed lymphocytes was normal. When the receptors were purified from fibroblasts with wheat germ agglutinin, we could not find a decrease in the binding affinity seen in the intact cells. No difference was observed in the magnitude of basal and insulin-stimulated autophosphorylation of insulin receptors from EBV-transformed lymphocytes between the control and myotonic dystrophy. Southern blot analysis of the insulin receptor gene revealed no restriction fragment length polymorphism associated with myotonic dystrophy. These findings suggest that there is no primary defect of the insulin receptor per se in terms of insulin binding and autophosphorylation in myotonic dystrophy. The reduction of the insulin binding to erythrocytes and fibroblasts may be caused by the plasma membrane abnormality that affects the binding affinity of the receptor.

Adult↗
PubMed1990

[A case of chondrosarcoma arising from the left first rib].

A 46-year-old female was admitted to our hospital because of a left supraclavicular tumor. The chest CT scan and MR imaging revealed that the tumor arose from the left first rib and developed into the supraclavicular region. In this case, we tried to resect the tumor using the so-called "trap-door" thoracotomy. Although removal of subclavian vessels and brachial plexus from the tumor was easily performed, we could not enough treat the vertebral side of the first rib through this thoracotomy without the T1 nerves injury. In cases of superior sulcus tumors developing into the posterior chest wall, a posterior incision combined with an anterior one will be useful to remove these tumors safely.

Chondrosarcoma↗