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H Hara

Publications and source records attributed to H Hara.

At least 109 records · Page 6Linked to original sources
PubMed2001

[Sensory extinction phenomenon of double simultaneous stimulation: the analysis of consecutive stroke series with acute and unilateral lesions].

We evaluated consecutive stroke patients with an acute, unilateral lesion, in order to elucidate the anatomical correlates and the clinical course of sensory extinction phenomenon as well as its relation with unilateral spatial neglect (USN) and anosognosia for hemiplegia (AHP). Subjects consisted of 76 patients with right cerebral hemispheric lesions (RHL) and 43 with left cerebral hemispheric lesions (LHL). Twelve of 76 patients with RHL and 18 of 43 patients with LHL were excluded from this study, because of consciousness disturbance, aphasia, severe sensory disturbance, hemianopia, or severe dementia. All of the patients included in this study had an ischemic or hemorrhagic stroke, who admitted to our hospital within 24 hours after the onset of stroke. We repeatedly examined the patients to detect the presence of sensory extinction phenomenon, USN, and AHP from their acute to chronic stage. The incidence of extinction phenomenon in RHL was 33% (11/19 with cortical lesions and 10/45 with deep-seated lesions). When we excluded the patients with a lacunar stroke or TIA, 10 of 13 patients with subcortical lesions had sensory extinction phenomenon. Nineteen of 21 patients with RHL who showed sensory extinction phenomenon also accompanied USN, and twelve had associated AHP. The sensory extinction phenomenon disappeared within 20 days in 6 of 10 patients with subcortical lesions and 3 of 11 with cortical lesions. In contrast, three of 25 (12%) patients with LHL showed extinction phenomenon, the incidence being much rarer than the lesion in the right. Of these, two had USN and one had AHP together. All the deficits disappeared within 20 days after the onset of stroke in patients with LHL. Our studies may show that subcortical lesions present with extinction phenomenon more frequently than cortical lesions, although the phenomenon caused by the subcortical lesions of often disappear in a few weeks.

Aged↗
PubMed2001

Effects of water depth on abdominal [correction of abdominails] aorta and inferior vena cava during standing in water.

During water immersion bradycardia and increase in stroke volume induce by changing in hydrostatic pressure. We hypothesised that the cardiac alterations with immersion are associates with an increase in venous return from lower body. Because the venous return reflects volume of capacitance vein e.g, inferior vena cava. Therefore, we clarified the effects of water immersion on the size in left ventricle, aorta, and vena cava.

Adult↗
PubMed2000

Effects of homocysteine on the binding of extracellular-superoxide dismutase to the endothelial cell surface.

Homocysteine is known to be a risk factor for several vascular diseases. Previously, we found a significant association between plasma homocysteine and plasma extracellular-superoxide dismutase (EC-SOD) levels. The binding of EC-SOD to human and bovine aortic endothelial cell cultures showed significant decreases after incubation with 10 microM homocysteine, whereas the expression of EC-SOD in fibroblast cell cultures was inhibited with a high concentration (1 mM) of homocysteine. Furthermore, binding of EC-SOD to heparin immobilized on plates was decreased with homocysteine. These observations suggested that homocysteine decreases the binding of EC-SOD to vascular endothelial cell surfaces by degradation of endothelial heparan sulfate proteoglycan, which results in a loss of the ability to protect endothelial cell surfaces from oxidative stress.

Animals↗
PubMed2000

Development of dendritic epidermal T cells with a skewed diversity of gamma delta TCRs in V delta 1-deficient mice.

One of the most intriguing features of gammadelta T cells that reside in murine epithelia is the association of a specific Vgamma/Vdelta usage with each epithelial tissue. Dendritic epidermal T cells (DETCs) in the murine epidermis, are predominantly derived from the "first wave" Vgamma5+ fetal thymocytes and overwhelmingly express the canonical Vgamma5/Vdelta1-TCRs lacking junctional diversity. Targeted disruption of the Vdelta1 gene resulted in a markedly impaired development of Vgamma5+ fetal thymocytes as precursors of DETCs; however, gammadeltaTCR+ DETCs with a typical dendritic morphology were observed in Vdelta1-/- mice and their cell densities in the epidermis were slightly lower than those in Vdelta1+/- epidermis. Moreover, the Vdelta1-deficient DETCs were functionally competent in their ability to up-regulate cytokines and keratinocyte growth factor-expression in response to keratinocytes. Vgamma5+ DETCs were predominant in the Vdelta1-/- epidermis, though Vgamma5- gammadeltaTCR+ DETCs were also detected. The Vgamma5+ DETCs showed a typical dendritic shape, gammadeltaTCR(high), and age-associated expansion in epidermis as observed in conventional DETCs of normal mice, whereas the Vgamma5- gammadeltaTCR+ DETCs showed a less dendritic shape, gammadeltaTCR(low), and no expansion in the epidermis, consistent with their immaturity. These results suggest that optimal DETC development does not require a particular Vgamma/Vdelta-chain usage but requires expression of a limited diversity of gammadeltaTCRs, which allow DETC precursors to mature and expand within the epidermal microenvironment.

Animals↗
PubMed2000

Aquaporin 4: lack of mRNA expression in the rat regenerating muscle fiber under denervation.

The recently identified water channel aquaporin 4 is a major component of the orthogonal arrays observed with freeze-fracture electron microscopy. We examined the expression of aquaporin 4 mRNA and protein in rat regenerating muscle under innervated and denervated conditions. We found decreased sarcolemmal immunostaining of aquaporin 4 in denervated regenerating muscle as opposed to innervated muscle. Quantitative reverse transcription-polymerase chain reaction revealed that aquaporin 4 mRNA was expressed in the innervated regenerating muscle; whereas it was not expressed in denervated muscle. Thus, lack of aquaporin 4 protein may be due to lack of aquaporin 4 mRNA in the denervated regenerating muscle. We conclude that the nerve supply influences expression of aquaporin 4 at the mRNA level in regenerating muscle.

Animals↗
PubMed2000

Isolation and characterization of a novel liver-specific gene, hepassocin, upregulated during liver regeneration.

By differential cDNA cloning coupled with Xenopus oocyte expression screening, we isolated a cDNA encoding a novel protein, termed 'hepassocin', the expression of which is upregulated in the regenerating rat liver. The cDNA contained a single open reading frame encoding a protein of 314 amino acids (ca. 34 kDa), including 24 amino acids of signal sequence. The protein expressed from the cDNA in Verots cells had activity to stimulate DNA synthesis in primary rat hepatocytes and was of 66 kDa or 34 kDa, under non-reducing or reducing conditions, respectively. Using an affinity column conjugated with the antibody raised against a peptide in a hydrophilic region, we purified hepassocin from the rat liver: it had a DNA synthesis-stimulating activity in hepatocytes. The hepassocin obtained here was 66 kDa, and the 34 kDa protein obtained under reducing conditions contained five cysteine residues, indicating that hepassocin is active as a homodimer. Northern blot analysis revealed that hepassocin mRNA (1.4 kb in length) occurred only in the liver, and in situ hybridization studies revealed its presence in parenchymal hepatocytes but not in endothelial cells. Furthermore, the expression of hepassocin mRNA was upregulated during compensatory hyperplasia after partial hepatectomy and regeneration after galactosamine treatment in the rat liver. These results suggest that hepassocin plays an important role in stimulating liver cell growth, through an autocrine mechanism.

Amino Acid Sequence↗
PubMed2000

Dual role of caspase-11 in mediating activation of caspase-1 and caspase-3 under pathological conditions.

Caspase-11, a member of the murine caspase family, has been shown to be an upstream activator of caspase-1 in regulating cytokine maturation. We demonstrate here that in addition to its defect in cytokine maturation, caspase-11-deficient mice have a reduced number of apoptotic cells and a defect in caspase-3 activation after middle cerebral artery occlusion (MCAO), a mouse model of stroke. Recombinant procaspase-11 can autoprocess itself in vitro. Purified active recombinant caspase-11 cleaves and activates procaspase-3 very efficiently. Using a positional scanning combinatorial library method, we found that the optimal cleavage site of caspase-11 was (I/L/V/P)EHD, similar to that of upstream caspases such as caspase-8 and -9. Our results suggest that caspase-11 is a critical initiator caspase responsible for the activation of caspase-3, as well as caspase-1 under certain pathological conditions.

Animals↗
PubMed2000

Accumulation of common T cell clonotypes in the salivary glands of patients with human T lymphotropic virus type I-associated and idiopathic Sjögren's syndrome.

To clarify the pathogenesis of human T lymphotropic virus type I (HTLV-I)-associated Sjögren's syndrome (SS), the TCR Vbeta gene usage by the infiltrating lymphocytes in the target organ was examined. The Vbeta families predominantly used in the labial salivary gland (LSG) from the HTLV-I-seropositive (HTLV-I+) SS patients were more restricted than those from the HTLV-I-seronegative (idiopathic) SS patients, and were commonly Vbeta5.2, Vbeta6, and Vbeta7. The single-strand conformation polymorphism analysis revealed that T cell clonotypes with Vbeta5.2, Vbeta6, and Vbeta7 accumulate in the LSG from the HTLV-I+ and idiopathic SS patients. Among junctional sequences of the most dominant Vbeta7 transcripts, the conserved amino acid motif (QDXG: X is any amino acid) was found in six of the five HTLV-I+ SS patients and was also detected in two of the five idiopathic SS patients. Using the probes specific to the motif, the Vbeta7 transcripts with the motif were detected in the LSG from all of the seven HTLV-I+ and five of the six idiopathic SS patients, but not from eight healthy subjects. The Vbeta7 transcripts with this motif were also detected in the HTLV-I-infected T cell lines obtained from the LSG of an HTLV-I+ SS patient. The accumulation of HTLV-I-infected T cells expressing TCR with the conserved motif was thus indicated. These T cells were commonly present in patients with idiopathic SS and are strongly suggested to most likely be involved in the pathogenesis of both HTLV-I-associated and idiopathic SS.

Adolescent↗
PubMed2000

Lomerizine, a Ca2+ channel blocker, reduces glutamate-induced neurotoxicity and ischemia/reperfusion damage in rat retina.

We examined the effects of a new Ca2+ channel blocker, lomerizine, on the intraocular hypertension-induced ischemia/reperfusion injury in rat retina and on the glutamate-induced neurotoxicity in rat cultured retinal neurons, and compared its effects with those of a Ca2+ channel blocker (flunarizine) and an N-methyl-D-aspartate receptor antagonist (MK-801). Morphometric evaluation at 7 days after ischemia/reperfusion showed that treatment with lomerizine (0.1 and 1 mg kg(-1), i.v.) prior to ischemia and again immediately after reperfusion dose-dependently reduced the retinal damage. Treatment with MK-801 (1 mg kg(-1), i.v.) before ischemia significantly reduced the resulting retinal damage. Flunarizine (0.1 and 1 mg kg(-1), i.v.) tended to reduce the retinal damage, but its effect did not reach statistical significance. In an in vitro study, pretreatment with lomerizine (0.1 and 1 microM) or flunarizine (1 microM) significantly reduced glutamate-induced neurotoxicity, the effects being concentration dependent. Lomerizine (1 microM) also exhibited protective effects against both the N-methyl-D-aspartate and kainate induced types of neurotoxicity. However, lomerizine (1 microM) had little effect on the neurotoxicity induced by ionomycin (1 microM) application. Glutamate-induced neurotoxicity was abolished by removing Ca2+ from the medium. These results indicate that lomerizine protects neuronal cells against retinal neurotoxicity both in vivo and in vitro, and that this Ca2+ channel blocker may be useful as a therapeutic drug against retinal diseases that cause neuronal injury, such as normal tension glaucoma (NTG).

Animals↗
PubMed2000

Constriction of resistance arteries determines l-NAME-induced hypertension in a conscious hamster model.

The influence of infusion of a nitric oxide (NO) synthase inhibitor, N(omega)-nitro-l-arginine methyl ester (l-NAME), on resistance arteries (diameter, 150 +/- 8 microm) and its relationship with hypertension were examined in conscious hamsters fitted with a dorsal skinfold window. After infusing l-NAME (10 and 30 mg/kg), hamsters showed immediate hypertension of +13 +/- 9 and +21 +/- 9 mm Hg, respectively, relative to basal values, and a maximum of +44 +/- 4 mm Hg at 30 min for the high-dose group. There was simultaneous significant vasoconstriction of the resistance arteries (A(0)) which reduced to 60 +/- 5% of baseline diameter at 3 h; however, there was no significant vasoconstriction in large and small arterioles with diameters diameters less than 70 microm. Blood flow rate in all the vessels decreased in consonance with the vasoconstriction of the resistance artery, irrespective of microvessel classification. These results indicate that the resistance artery plays a key role as a regulator and microvascular resistance in determining blood flow distribution and hypertension when a NO synthase inhibitor is infused.

Animals↗
PubMed2000

Interventricular methotrexate therapy for carcinomatous meningitis due to breast cancer: a case with leukoencephalopathy.

A 46-year-old woman presented with paraplegia and severe lumbago. She had had a radical mastectomy for left breast cancer 10 years earlier, and 6 months prior to presentation she completed CMF chemotherapy for treatment of retroperitoneal metastasis. CT and MRI to identify potential causes of the paraplegia and lumbago showed leptomeningeal carcinomatosis due to dissemination from invasive recurrence of the retroperitoneal tumor. An Ommaya reservoir was inserted, and infusion of intrathecal methotrexate (MTX; 5 mg twice weekly) began. Her clinical symptoms improved after receiving 53 mg MTX. However, after receiving 83 mg MTX, the patient became dizzy from leukoencephalopathy. Although administration of prednisolone mostly resolved her symptom, the patient died 9 months after the diagnosis of carcinomatous meningitis.

Antimetabolites, Antineoplastic↗
PubMed2000

Subcutaneous abscesses in a patient with ulcerative colitis.

Ulcerative colitis (UC) is a clinical form of inflammatory bowel disease. The association of pyoderma gangrenosum or erythema nodosum with UC is well known. In addition, pustular eruption has been reported in UC. We describe a patient with UC who exhibited subcutaneous abscesses, as well as pustular eruption with a clinical course paralleling that of UC exacerbation.

Abscess↗
PubMed2000

Maternal program of apoptosis activated shortly after midblastula transition by overexpression of S-adenosylmethionine decarboxylase in Xenopus early embryos.

When we studied polyamine metabolism in Xenopus embryos, we cloned the cDNA for Xenopus S-adenosylmethionine decarboxylase (SAMDC), which converts SAM (S-adenosylmethionine), the methyl donor, into decarboxylated SAM (dcSAM), the aminopropyl donor, and microinjected its in vitro transcribed mRNA into Xenopus fertilized eggs. We found here that the mRNA injection induces a SAM deficient state in early embryos due to over-function of the overexpressed SAMDC, which in turn induces inhibition of protein synthesis. Such embryos developed quite normally until blastula stage, but stopped development at the early gastrula stage, due to induction of massive cell dissociation and cell autolysis, irrespective of the dosage and stage of the mRNA injection. We found that the dissociated cells were TUNEL-positive, contained fragmented nuclei with ladder-forming DNA, and furthermore, rescued completely by coinjection of Bcl-2 mRNA. Thus, overexpression of SAMDC in Xenopus embryos appeared to switch on apoptotic program, probably via inhibition of protein synthesis. Here, we briefly review our results together with those reported from other laboratories. After discussing the general importance of this newly discovered apoptotic program, we propose that the maternal program of apoptosis serves as a surveillance mechanism to eliminate metabolically severely-damaged cells and functions as a 'fail-safe' mechanism for normal development in Xenopus embryos.

Adenosylmethionine Decarboxylase↗
PubMed2000

Divergence of glyceraldehyde-3-phosphate dehydrogenase isozymes in Saccharomyces cerevisiae complex.

Although sake yeasts are placed in Saccharomyces cerevisiae, we have been interested in their difference from the other subgroups of the species, and examined their proteins. When SDS-PAGE patterns of their soluble proteins were compared, specific differences between subgroups were found in their 36,000 Da regions. Proteins isolated therefrom were found to be subunits of three isomers of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from their N-terminal amino acid sequences and identified with anti-GAPDH serum. Therefore, comparison of zymogram was carried out by a modified method: denatured monomers were observed and the enzyme activity of their oligomers was not considered. SDS-PAGE patterns of all the sake yeasts differed from those of the other strains of S. cerevisiae. Strains of Saccharomyces bayanus showed uniform patterns which are different from the above two groups. Saccharomyces pastorianus strains resembled S. bayanus and were partly similar to S. cerevisiae in their patterns, in agreement with the hypothesis that S. pastorianus is a hybrid between these two species. Patterns of S. paradoxus appeared to be rather similar to those of sake yeasts. Results on the other species of the genus and on the preliminary experiments on PAGE of native isozymes are also described.

Alcoholic Beverages↗
PubMed2000

Induction of pancreatic trypsin by dietary amino acids in rats: four trypsinogen isozymes and cholecystokinin messenger RNA.

We previously demonstrated that feeding a diet containing a high level of amino acid mixture simulating casein (AA) induced an increase in pancreatic protease activities in rats. In the present study, this effect of dietary AA was further characterized with three separate experiments. These experiments (1) examined periodic changes in pancreatic and small intestinal trypsin activities after switching from a 20% (a normal nitrogen level) AA diet to a 60% AA (a high nitrogen level) diet; (2) measured the abundance of mRNA for four trypsinogen isozymes and for intestinal cholecystokinin (CCK) and secretin in rats fed 20% and 60% AA diets for 10 days compared with rats fed 20% and 60% casein diets; and (3) measured the abundance of mRNA for four trypsinogen isozymes after chronic administration of CCK. Trypsin activities were gradually increased in both the pancreas and the small intestinal lumen and reached maximum at 5 days after the switch to the 60% AA diet (Exp. 1). This result is evidence that the increase in the protease activity in the pancreas is due to enhancement of pancreatic trypsin production. In experiment 2, pancreatic trypsinogen isozymes I, II, III, and IV mRNA abundance were evaluated by the Northern blotting method using cDNA probes specific for each isozyme mRNA. Abundance of trypsinogen mRNA without trypsinogen I tended to increase in the rats fed the 60% casein diet but tended to decrease in the rats fed the 60% AA diet compared with the respective normal nitrogen level diet groups without significant difference. CCK mRNA abundance in the jejunal mucosa increased as a result of feeding the 60% casein diet, but not the 60% AA diet. Subcutaneous CCK injections (3.5 nmole/kg body weight/day, twice daily, at 8:30 am and 7:30 pm) for 10 days resulted in increased pancreatic trypsin activity, whereas the changes in mRNA of the four trypsinogen isozymes was similar between the 20% and 60% casein groups but differed between the 20% and 60% AA groups (Exp. 3). These results suggest that CCK is not involved in the induction of pancreatic trypsin that occurs with feeding of a high AA diet and that the mechanism of protease induction by dietary AA is different from that in the case of dietary protein.

Journal Article↗