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Biomedical subjects

O Hashimoto

Publications and source records attributed to O Hashimoto.

At least 37 records · Page 2Linked to original sources

A family with an atonic variant of paroxysmal kinesigenic choreoathetosis and hypercalcitoninemia.

We report a family with an incompletely atonic variant of paroxysmal kinesigenic choreoathetosis (PKC). Three members of the family experienced attacks of muscle weakness which resembled the choreoathetotic attacks that occur in PKC in terms of their kinesigenicity and duration, clarity of consciousness during the attacks, good therapeutic response to low doses of phenytoin, and familial transmission, but differed from choreoathetotic attacks in PKC in that they were atonic. All three affected individuals were hypercalcitoninemic.

Adult↗

Renal hemodynamics in Otsuka Long-Evans Tokushima fatty rat, a model rat of spontaneous non-insulin-dependent diabetes mellitus with obesity.

Renal hemodynamic features in obese non-insulin-dependent diabetic rats remain unknown. We investigated renal hemodynamic and morphologic changes in Otsuka Long-Evans Tokushima Fatty (OLETF) rats at the age of 5 and 10 months compared with age-matched lean nondiabetic control rats (LETO). OLETF rats showed obesity compared with age-matched LETO rats. Hyperglycemia was mild in 5-month-old OLETF rats and moderate in 10-month-old OLETF rats. The absolute value for glomerular filtration rate (GFR) was significantly higher in OLETF rats than in age-matched LETO rats at the age of 5 and 10 months. Ten-month-old OLETF rats had significantly higher absolute values for renal plasma flow (RPF) than age-matched LETO rats but not 5-month-old OLETF rats. Stepwise multiple regression analysis revealed that body weight was a powerful determinant of GFR and RPF. When factored for body weight, no difference in GFR was demonstrated between 5-month-old OLETF and LETO rats, whereas 10-month-old OLETF rats still had significantly higher GFR and RPF than age-matched LETO rats. Renal hypertrophy was demonstrated in both 5- and 10-month-old OLETF rats even when factored for body weight. Glomerular volume was significantly increased in 10-month-old OLETF rats, but the ratio of glomerular volume to body weight was not different among the groups. Both absolute value for glomerular capillary length free from mesangial area and the value factored for glomerular area were significantly longer in OLETF rats than in age-matched LETO rats. Mesangial matrix expansion was remarkable in 10-month-old OLETF rats, and the glomerular sclerosis index was significantly higher in 10-month-old OLETF rats than in age-matched LETO rats. Stepwise multiple regression analysis revealed that body weight, hemoglobin A1c, and hypertriglyceridemia were powerful determinants for kidney weight and glomerular volume. These data suggest that renal hyperfiltration and hypertrophy observed in 10-month-old OLETF rats are related to diabetic metabolic disorders and that obesity-related conditions may be involved in the renal hemodynamic and morphologic features in OLETF rats.

Animals↗

Highly restricted T cell repertoire shaped by a single major histocompatibility complex-peptide ligand in the presence of a single rearranged T cell receptor beta chain.

The T cell repertoire is shaped by positive and negative selection of thymocytes through the interaction of alpha/beta-T cell receptors (TCR) with self-peptides bound to self-major histocompatibility complex (MHC) molecules. However, the involvement of specific TCR-peptide contacts in positive selection remains unclear. By fixing TCR-beta chains with a single rearranged TCR-beta irrelevant to the selecting ligand, we show here that T cells selected to mature on a single MHC-peptide complex express highly restricted TCR-alpha chains in terms of Valpha usage and amino acid residue of their CDR3 loops, whereas such restriction was not observed with those selected by the same MHC with diverse sets of self-peptides including this peptide. Thus, we visualized the TCR structure required to survive positive selection directed by this single ligand. Our findings provide definitive evidence that specific recognition of self-peptides by TCR could be involved in positive selection of thymocytes.

Amino Acid Sequence↗

Renal hemodynamics in rats with cadmium-induced nephropathy.

Glomerular filtration rate (GFR) is known to decline in patients with cadmium (Cd)-induced nephropathy. However renal hemodynamics in Cd-induced nephropathy remain unknown. We investigated renal hemodynamics in experimental Cd-induced nephropathy. Male Sprague-Dawley rats were given 0.18 mg/rat of cadmium chloride i.p. three times a week for 3 and 16 months. Age-matched control rats were given physiological saline. Mean arterial pressures after 3 and 16 months were identical among the groups. In comparison with age-matched control rats, significant decreases in GFR associated with a significantly lower filtration fraction (FF) were demonstrated in both groups of Cd-treated rats, but the changes were more prominent in the 16-month Cd-treated rats. Renal plasma flow was significantly decreased in the 3-month Cd-treated rats whereas it was preserved in the 16-month Cd-treated rats because of anemia. Urinary sodium excretions in both groups of Cd-treated rats were significantly greater than those in the respective control rats. On light microscopic examination, only mild degeneration of tubular cells and interstitial edema in limited areas of the proximal tubules were observed in the 3-month Cd-treated rats. In the 16-month Cd-treated rats multifocal tubular atrophy and interstitial fibrosis in the outer cortex were noted. Electron microscopic examinations revealed conspicuous degenerative changes in the proximal tubular epithelial cells, diffuse thickening of glomerular basement membranes, and foot process fusions in 16-month Cd-treated rats. These data suggested that the decline in GFR in the Cd-treated rats resulted mainly from the decline in FF, which might be functional rather than structural in origin and might be associated with proximal tubular dysfunctions.

Animals↗

Increased expression of vascular endothelial growth factor is associated with tumor progression in hepatocellular carcinoma.

Vascular endothelial growth factor is a potent direct-acting angiogenic factor. Early in hepatocarcinogenesis, hepatocellular carcinomas do not show hypervascularity; at later stages, they require abundant arterial blood flow. We investigated the role of vascular endothelial growth factor in hepatocellular carcinoma arterialization. We studied 51 patients with hepatocellular carcinoma. All patients had undergone hepatic arteriography. Vascular endothelial growth factor expression was investigated by immunohistochemistry (n = 51) and in situ hybridization (n = 13), and the changes in vascular endothelial growth factor expression were evaluated in relation to tumor differentiation and changes in tumor vascularity. The expression of vascular endothelial growth factor isoforms in hepatocellular carcinomas was also analyzed by reverse transcriptase-polymerase chain reaction (n = 10). Vascular endothelial growth factor expression was detected in hepatoma cells and hepatic stellate cells, and increased vascular endothelial growth factor expression was associated with tumor dedifferentiation. Vascular endothelial growth factor expression in hypervascular hepatocellular carcinomas was greater than in those not showing hypervascularity. The major vascular endothelial growth factor isoforms expressed in hepatocellular carcinoma were 121 and 165. These findings indicate that vascular endothelial growth factors 121 and 165 play a critical role in the process of angiogenesis in hepatocellular carcinomas.

Aged↗

Correlation between Bcl-X expression and B-cell hybridoma apoptosis induced by activin A.

In this study, we examined the role of bcl-XL and bcl-XS in apoptotic cell death of HS-72 cells induced by activin A. Immunoblot analysis revealed that a band of Bcl-XL was detected in HS-72 cells cultured with or without activin A. Although untreated HS-72 cells did not express Bcl-XS, the expression of Bcl-XS was significantly increased when cultured with activin A. We also investigated the expression of Bcl-XS and Bcl-XL in HS-72 cells cultured with activin A in the presence of protein kinase C inhibitor 1-(5-isoquinotinesulfonyl)-2-methylpiperazine dihydrochloride (H7), which suppressed apoptosis in HS-72 cells induced by activin A. Exposure to H7 apparently increased the level of Bcl-XL in HS-72 cells cultured with or without activin A. In contrast, no detectable band of Bcl-XS was found in HS-72 cells cultured with activin A and H7. These findings indicate that Bcl-XL upregulation and Bcl-XS downregulation induced by H7 might correlate with the suppression of activin A-induced apoptosis in B-lineage cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

The role of activin type I receptors in activin A-induced growth arrest and apoptosis in mouse B-cell hybridoma cells.

Activins transduce their signals by binding to activin type I receptors and activin type II receptors, both of which contain a serine/threonine kinase domain. In this study, we established stable transfectants expressing two types of activin receptors, ActRI and ActRIB, to clarify the role of these receptors in activin signalling for growth inhibition in HS-72 mouse B-cell hybridoma cells. Over-expression of ActRI suppressed activin A-induced cell-cycle arrest in the G1 phase caused by inhibition of retinoblastoma protein phosphorylation through induction of p21CIP1/WAF1, a cyclin-dependent kinase inhibitor, and subsequent apoptosis. In contrast, HS-72 clones that over-expressed ActRIB significantly facilitated activin A-induced apoptosis. These results indicate that ActRI and ActRIB are distinct from each other and that the ActRI/ActRIB expression ratio could regulate cell-cycle arrest in the G1 phase and subsequent apoptosis in HS-72 cells induced by activin A.

Activin Receptors, Type I↗

Molecular cloning and expression of cynomolgus monkey interleukin-1beta cDNA.

The cynomolgus monkey cDNA encoding interleukin-1beta (IL-1beta) was molecularly cloned by the reverse transcription polymerase chain reaction from a cDNA library of adherent splenocytes stimulated with lipopolysaccharides. The sequence analysis showed that the monkey IL-1beta cDNA encodes a protein of 268 amino acids and displays a high degree (90%) of homology with the human counterpart. Substitution of amino acids resides mainly in the leader sequences of IL-1beta when compared with those of human IL-1beta. This cloned monkey IL-1beta cDNA was used to express in Escherichia coli as a fusion protein with thioredoxin and in insect cells infected with a recombinant baculovirus after molecular modification where monkey IL-1beta signal sequences were placed prior to the mature sequences of IL-1beta for efficient secretion in insect cells. Recombinant monkey IL-1beta expressed in both systems was shown to react with rabbit antihuman IL-1beta antiserum by Western blot analysis and to have the biological activity of IL-1beta in a bioassay.

Amino Acid Sequence↗

Distribution of lectin binding in spermatogonia of Syrian hamsters in gonadally active and inactive states.

Lectin binding patterns in spermatogonia of Syrian hamsters in gonadally active and inactive states were examined by light and electron microscopy. After exposure to a short day cycle (SD), the testis weight and the diameter of seminiferous tubules decreased, reaching the minimum at 13 weeks. At that time, spermatogenesis was severely disrupted. In the animals kept exposed to an SD, spermatogenesis reinitiated spontaneously after 23 weeks. In the animals transferred to a long day cycle (LD) after exposure to an SD for 13 weeks, spermatogenesis reinitiated only 4 weeks later. As to the lectin binding, Dolichos biflorus agglutinin (DBA) bound specifically to spermatogonia. The number of DBA-positive spermatogonia per one seminiferous tubule increased until 13 weeks after exposure to an SD, and then gradually decreased. DBA bound to only type A spermatogonia in active testes, whereas it bound to type A, intermediate and type B spermatogonia in inactive testes. Moreover, SDS-PAGE and Western blot analysis of testes in active and inactive states indicated that DBA-binding bands (115 kDa, 76 kDa) in inactive testes were intense compared with those in active testes. The 82 kDa band was detected only in inactive testes. These results supported the finding obtained from lectin histochemistry. DBA-binding glycoprotein was detected in all types of spermatogonia in inactive testes, suggesting that this glycoprotein way concern the active/inactive state of spermatogenesis. The present study also indicated that DBA is a useful marker for spermatogonia in inactive testes of Syrian hamster.

Animals↗

Serum carboxy-terminal cross-linked telopeptide of type I collagen reflects bone metastasis in hepatocellular carcinoma.

Carboxy-terminal telopeptide of type I collagen (ICTP) is a degradation product of type I collagen. In this study, we investigated the usefulness of measuring the serum ICTP concentration for diagnosing and monitoring bone metastasis from hepatocellular carcinoma (HCC). The serum concentrations of ICTP, type I procollagen carboxy-terminal propeptide (PICP), type III procollagen aminoterminal propeptide (PIIIP), type IV collagen (Ty IV), type IV collagen 7S-domain (7S), and hyaluronic acid (HA) were measured in patients with liver cirrhosis, HCC with or HCC without bone metastasis, and in healthy controls. The diagnostic efficiency of the serum ICTP and fibrosis marker levels in the HCC patients with and without bone metastasis was evaluated using receiver operating characteristic curves. We also retrospectively examined the changes in the serum ICTP levels before and after bone metastasis in the HCC patients. The serum ICTP level was significantly higher in the HCC patients with bone metastasis than in the patients with other diseases and the healthy controls. The serum PICP, PIIIP, Ty IV, 7S and HA levels of the HCC patients with bone metastasis did not differ significantly from those of the patients without bone metastasis. The diagnostic efficiency for HCC with bone metastasis was 87% for ICTP, 51% for PICP, 65% for Ty IV, 55% for PIIIP and 51% for HA. During the follow-up, the changes in the serum ICTP values paralleled the behavior of bone metastasis. These results indicate that the measurement of serum ICTP concentration is useful for detecting and monitoring HCC patients with bone metastasis.

Adult↗

[Study on evaluating methods for the quality control of glycoprotein products. (II)--Erythropoietin products. Part 2].

Using recombinant human erythropoietin (rh-EPO) from three different sources, the usefulness of HPAEC-PAD (high-pH anion exchange chromatography with pulsed amperometric detection) for evaluation of carbohydrate moieties of rh-EPO products was evaluated. It is well known that in vivo bioactivity and metabolic fate of EPO are dependent on the number of sialic acids and the degree of branching in the carbohydrate moieties. Here we show that HPAEC analysis reveals differences in the number of sialic acids as well as in the structure of desialylated N-glycans among the rh-EPO products. Therefore, HPAEC is useful for evaluation of the quality of rh-EPO products.

Carbohydrate Sequence↗

[Perforation of the bladder by a peritoneal catheter: an unusual late complication of ventriculo-peritoneal shunt].

Late perforation of the bladder by an abdominal catheter of a ventriculoperitoneal (VP) shunt is extremely rare. We report the successful treatment of a patient who presented with this complication. An 82-year-old woman received a V-P shunt for normal pressure hydrocephalus following subarachnoid hemorrhage. Ten years later she was admitted to our hospital with neck pain. A few days after admission, the tip of the peritoneal catheter was found to be protruding from the urethra during urination. Subsequently, the patient developed meningitis. Contrast study of the distal tubing demonstrated the continuity of the peritoneal shunt tube. After the entire system was removed, antibiotic treatment was administered for 2 weeks. and a new VP shunt was placed on the opposite side. The post-operative course was uneventful. Previous reports regarding complications after the placement of a VP-shunt show that periodic chest and abdominal X-ray studies are important. In this case, however, the peritoneal tube was not able to be observed on abdominal plain film. For this reason, an unfaded radiopaque tube is necessary if there is to be early diagnosis of late organic perforation by a peritoneal shunt tube.

Aged↗

A novel role of follistatin, an activin-binding protein, in the inhibition of activin action in rat pituitary cells. Endocytotic degradation of activin and its acceleration by follistatin associated with cell-surface heparan sulfate.

There are two types of the activin-binding protein follistatin (FS), FS-288 and FS-315. These result from alternative splicing of mRNA. FS-288 exhibits high affinity for cell-surface heparan sulfate proteoglycans, whereas FS-315 shows low affinity. To understand the physiological role of cell-associated FS, we investigated the binding of activin to cell-associated FS and its behavior on the cell surface using primary cultured rat pituitary cells. Affinity cross-linking experiments using 125I-activin A demonstrated that activin bound to rat pituitary cells via FS as well as to their receptors on the cell surface. FS-288 promoted the binding of activin A to the cell surface more markedly than FS-315. When the cells were incubated with 125I-activin A in the presence of FS-288, significant degradation of activin A was observed, and this was dependent on the FS-288 concentration. This activin degradation was abolished by heparan sulfate, chloroquine, and several lysosomal enzyme inhibitors. Moreover, FS-288 stimulated cellular uptake of activin A, whereas chloroquine suppressed lysosomal degradation following internalization, as demonstrated by microscopic autoradiography. These results suggest that cell-associated FS-288 accelerates the uptake of activin A into pituitary cells, leading to increased degradation by lysosomal enzymes, and thus plays a role in the activin clearance system.

Activin Receptors↗

Therapeutic effects of restricted diet and exercise in obese patients with fatty liver.

BACKGROUND/AIMS: The incidence of obese patients with fatty liver has recently increased in Japan as well as in the United States and Europe. Fatty liver may occasionally progress to liver cirrhosis. In this study, we have compared the effects of restricted diet and exercise versus no treatment in obese patients with fatty liver. METHODS: Twenty-five obese patients with fatty liver were divided into treated and control groups. Fifteen obese patients followed a program of restricted diet (ideal weight x 25 Cal x kg(-1)) and exercise (walking or jogging) for a trial period of 3 months. No changes in diet or lifestyle were made by the other 10 patients during the same trial period. Blood biochemical tests and liver histology were compared in all patients before and after the trial. RESULTS: In the treated group, weight, blood biochemical data such as aminotransferase, albumin, cholinesterase, total cholesterol and fasting blood glucose values, and steatosis were significantly decreased after the trial. In the control group, there were no significant differences in the clinical and histological findings before and after the trial. CONCLUSIONS: These results indicate that restricted diet and exercise therapy, such as walking and jogging, are useful means of improving blood biochemical data and histological findings in liver tissues related to fatty liver.

Adolescent↗

Transmission routes and clinical courses in sporadic acute hepatitis C.

Between March 1994 and March 1996 we studied transmission routes and clinical courses in eight patients with sporadic acute hepatitis C (two men, six women). Of the eight patients, three were treated for another illness 1-2 months before the onset of hepatitis, one was a parenteral drug abuser, one had an accidental needlestick injury and two had sexual contact with a partner with chronic hepatitis C virus (HCV) infection. Clinical courses included four women whose HCV RNA and alanine aminotransferase (ALT) became persistently negative without treatment, and four men and two women with the same results following interferon (IFN) treatment. It is thought that IFN therapy may prevent the progression to chronic liver disease. Results from this study might be useful in the future management of patients with sporadic acute hepatitis C.

Acute Disease↗

Follistatin-like immunoreactivity in the cytoplasm and nucleus of spermatogenic cells in the rat.

Immunohistochemistry using an antiserum raised against the synthetic follistatin peptide (residues 123-134) was used, in the present study, to detect the stage-specific appearance of immunoreactive follistatin in the rat testis. Follistatin immunoreactivity was not found in Sertoli and Leydig cells, while it was clearly detected in spermatogenic cells. Follistatin-like immunoreactivity was detected in the cytoplasm and nucleus of late pachytene spermatocytes. Although the reaction in the cytoplasm disappeared after meiosis, it continued to be intense in the nucleus from pachytene spermatocytes to round spermatids. This finding indicated that follistatin or its closely related peptide produced in late pachytene spermatocytes migrates from the cytoplasm to the nucleus. We subjected rat testis homogenate to affinity chromatography on a sulfate-cellulofine and anti-follistatin Cys (123-134)-Affi-Gel Hz column followed by reverse-phase HPLC and analyzed the resulting fractions by Western blotting using follistatin antiserum. Three major bands at 57, 45 and 39 kDa or four bands at 52, 44, 39 and 34 kDa were detected in crude preparations from rat testis homogenate, under reducing or non-reducing SDS-PAGE respectively. The protein from rat testis, which was recognized by anti-follistatin (123-134) antiserum, exhibited a characteristic pattern for follistatin on SDS-PAGE, i.e. slower migration under reducing conditions than under non-reducing conditions, suggesting that it was follistatin or its closely related protein. Follistatin or its closely related protein may be a stage-specific modulator of spermatogenesis. Since follistatin-like immunoreactivity was not found in oocytes in any stage of development from embryonic to adult rats, it may act in an event specific to spermatogenesis, such as nuclear condensation.

Animals↗

Follistatin and its role as an activin-binding protein.

Follistatin (FS), a specific binding protein for activin, neutralizes the diverse actions of activin by forming an inactive complex with activin. FS is a monomer derived from two polypeptide core sequences of 288 (FS-288) and 315 (FS-315) amino acids originated from alternatively spliced mRNA. We purified six molecular forms of FS from porcine ovaries. Their structural differences were caused by truncation of the COOH-terminal region and/or the presence of carbohydrate chains, resulting in the formation of FS-288, FS-315 and FS composed of 303 amino acids (FS-303) in various forms of glycosylation on the two potential Asn-linked glycosylation sites. All six molecular species have almost the same activin binding activity (Kd = 540-680 pM). By contrast, the COOH-terminal truncated form, FS-288, showed much higher affinity for heparan sulfate proteoglycans of the cell surface than FS-303, whereas the intact form of FS, FS-315, had no affinity. Furthermore, FS-288 more effectively blocked the suppression of follicle-stimulating hormone (FSH) secretion from rat pituitary cells by activin. This implies that activin binds to the cell surface through FS-288 which adheres to the cell surface. To clarify the physiological role of cell-associated FS, we then investigated the binding of activin to cell-associated FS and the fate of cell surface-bound activin and FS using primary cultured rat pituitary and ovarian granuloma cells. When the cells were incubated with 125I-activin A in the presence of FS-288 or 315, the binding of activin A to the cell surface was promoted much more markedly by FS-288 than by FS-315. The amounts of radioactivity recovered in trichloroacetic acid-soluble fractions (degraded activin) from the incubation medium were greatly increased by the addition of FS-288. This increase was abolished by heparan sulfate, monensin (an endocytosis inhibitor), chloroquine (a lysosome function inhibitor) and several lysosomal enzyme inhibitors. These results suggest that cell-associated FS-288 accelerates the internalization of activin into the cells, leading to its degradation by lysosomal enzymes, and that cell surface-associated FS therefore plays a role in the clearance system of activin.

Activins↗