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Biomedical subjects

H Hashimoto

Publications and source records attributed to H Hashimoto.

At least 199 records · Page 11Linked to original sources
PubMed1997

Distinct regulation of two hydroxysteroid sulfotransferases, ST2A1 and ST2A2, by growth hormone: a unique type of growth hormone regulation in rats.

In the present study, changes in the mRNAs of two major forms of hydroxysteroid sulfotransferases (STs), ST2A1 and ST2A2, have been determined in different growth hormone (GH) states. Hepatic ST2A1 mRNA was detected in both sexes of mature Sprague-Dawley rats. The level was 5 times higher in the females than in the males. ST2A1 mRNA was undetectable in GH-deficient animals, such as hypophysectomized rats and spontaneous dwarf rats. Continuous infusion of GH (mimicking the female secretory pattern) increased hepatic levels of ST2A1 mRNA in both GH-deficient animals. ST2A2 mRNA was detected only in the livers of mature female rats and in both sexes of GH-deficient animals. Intermittent injection of GH (mimicking male secretory pattern) strongly suppressed hepatic levels of ST2A2 mRNA in both GH-deficient animals. These results indicate that pituitary GH independently regulates both ST2A1 and ST2A2 at the pretranslational levels. These differences in GH responses between ST2A1 and ST2A2 are in good agreement with their female-dominant and female-specific modes of expression in normal rats. Furthermore, the present study demonstrates a unique response of ST2A2 to the secretory pattern of GH among the drug-metabolizing enzymes in rat livers, in which ST2A2 mRNA levels are suppressed by the male secretory pattern but not by the female secretory pattern of GH.

Animals↗
PubMed1997

Transposon tagging in rice.

To develop an efficient gene isolation method for rice we introduced the maize Ac/Ds system into rice. Extensive analysis of their behavior in rice for several generations indicated that Ac and Ds in the presence of Ac transposase gene actively transpose in rice. A wide spectrum of mutations affecting growth, morphogenesis, flowering time and disease resistance have been obtained in the population carrying Ac/Ds and some of them were genetically analyzed. Main efforts are currently being made to isolate genes responsible these mutations. In addition, a number of Ac/Ds were mapped on chromosomes and mapped elements will be used in the future for directed tagging of genes with known chromosomal positions.

Cloning, Molecular↗
PubMed1997

Mechanisms of KE298, 2-acetylthiomethyl-3-(4-methylbenzoyl) propionic acid, to suppress abnormal synovial cell functions in patients with rheumatoid arthritis.

OBJECTIVE: 2-Acetylthiomethyl-3-(4-methylbenzoyl) propionic acid, KE298, a derivative or propionic acid developed in Japan has been shown to be effective for suppressing disease activity of rheumatoid arthritis (RA) in clinical trials in Japan. It is thus a candidate as a new disease modifying antirheumatic drug (DMARD). We analyzed effects of KE298 on synovial fibroblast-like cells in patients with RA to obtain insight into the clinical application of this medication. METHODS: RA synovial fibroblast-like cells were co-cultured with KE298 at 10(-4)-10(-5) M in the presence or absence of tumor necrosis factor-alpha 2 ng/ml, and their subsequent proliferative responses and proinflammatory cytokine and matrix metalloproteinase (MMP) production at the mRNA and protein levels were measured. Effects of KE298 on MMP-1 gene transcription and AP-1 transcription factor expression of RA synovial cells were studied by chloramphenicol acetyltransferase assay and gel shift assay, respectively. RESULTS: KE298 inhibited proliferation of RA synovial cells, proinflammatory cytokine production, and MMP-1 production mainly by reducing their transcription via downmodulation of AP-1 transcription factor. CONCLUSION: KE298 inhibits aberrant synovial cell functions of patients with RA by downregulating gene transcription, suggesting clinical application and usefulness of this new DMARD.

Antirheumatic Agents↗
PubMed1997

[A clinicopathological study on carcinoma of the renal pelvis and ureter].

We investigated the clinicopathological features of 62 patients with transitional cell carcinoma of the renal pelvis and ureter. Four patients had been treated for bladder cancer. Among 58 patients without precedent bladder cancer, 6 had coexistent bladder cancer and bladder cancer subsequently developed in 13. The 5-year cause-specific survival rate was 33% in cases with coexistent bladder cancer, 75% in those with subsequent bladder cancer and 62% in patients without association of bladder cancer. Distant metastases were found in 23 of 62 (37%) cases, the most frequent site being lymph nodes. The site of the primary tumor (renal pelvis and/or ureter) and the pathological findings such as grade, stage, type of infiltration, venous and lymphatic invasion, were significantly correlated to cause-specific survival. Multivariate analysis showed the most influential factors to be the type of infiltration and the site of the primary tumor. Therefore, patients with INF beta or gamma tumors both in the renal pelvis and ureter had a poor prognosis. However, association of bladder cancer was not related to survival.

Adult↗
PubMed1997

Tissue reconstruction of gynecologic tumor cells in the rotation culture system.

Tissue reconstruction of various kinds of gynecologic malignant tumor cell lines was studied using the rotation-culture system. The reconstructed cell aggregates were examined histologically using both light and electron microscopy. Our established cell lines used in this study were uterine cervical epidermoid carcinoma, endometrial adenocarcinoma, ovarian malignant tumor and uterine sarcoma. All of the reconstructed aggregates from each cell line were very similar to the original tumor tissue. In the case of a well differentiated type of adenocarcinoma derived from the ovarian cancers or the endometrial cancers, papillary cell aggregates (grape-like structures) and/or hollow cell ball (gland alveolus-like) structures were observed. The individual cells were adjoined with by desmosomes and well developed microvilli protruded from the free surface of the cells. On the other hand large cell non-keratinizing squamous cell carcinoma cells formed spherical-shaped aggregates that showed a stratified structure similar to pearl formation. Sarcoma cells formed solid clusters while desmosomes or desmosome-like junctions were not detected. Rotation culture is an excellent method to reveal diagnosis of the original tumor and tumorigenesis by investigating a reconstructed tissue from peritoneal effusions because the reconstructed tissue is similar to the original tumor.

Adenocarcinoma↗
PubMed1997

Histogenesis of hollow cell ball structure of ovarian and endometrial adenocarcinoma cells in vivo and in vitro.

Hollow cell ball structure is often found in the ascites of adenocarcinoma patients. How to form a hollow cell ball structure was studied in vivo and in vitro, using the human cell lines derived from ovarian and endometrial adenocarcinomas. The hollow cell ball structure was formed by horizontal rotation culture of 1 x 10(7) single-suspended cells for 24 hours or by transplanting 1 x 10(6) single-suspended cells into the peritoneal cavity of nude mouse for 24 hours. At one month after transplantation hemi-cyst and hollow cell ball structure were formed in the outermost layer of the grafted tumor on the intraperitoneal serous membrane in the nude mouse. And also great number of floating hollow cell ball structure in the ascites were observed. These results suggest that mechanisms of formation of hollow cell ball structure found in the ascites; one by cell aggregate of single cells, sometimes inner cells of cell aggregate fall into necrosis or secretes mucus inside and make a hollow cell ball structure and another by the removed as the hollow cell ball structure grown from hemi-cyst on the surface of intraperitoneal grafted tumor.

Adenocarcinoma↗
PubMed1997

Development and evaluation of totally implantable ventricular assist system using a vibrating flow pump and transcutaneous energy transmission system with amorphous fibers.

We have developed a vibrating flow pump (VFP) that can generate oscillated blood flow with a relatively high frequency (10-50 Hz) for a totally implantable ventricular assist system (VAS). To evaluate the newly developed VAS, left heart bypasses, using the VFP, were performed in chronic animal experiments. Hemodynamic parameters were recorded in a data recorder in healthy adult goats during an awake condition and analyzed in a personal computer system through an alternating-direct current converter. Basic performance of the total system with a transcutaneous energy transmission system were satisfactory. During left ventricular assistance with the VFP, Mayer wave fluctuations of hemodynamics were decreased in the power spectrum, the fractal dimensions of the hemodynamics were significantly decreased, and peripheral vascular resistance was significantly decreased. These results suggest that cardiovascular regulatory nonlinear dynamics, which mediate the hemodynamics, may be affected by left ventricular bypass with oscillated flow. The decreased power of the Mayer wave in the spectrum caused the limit cycle attractor of the hemodynamics and decreased peripheral resistance. These results suggest that this newly developed VAS is useful for the totally implantable system with unique characteristics that can control hemodynamic properties.

Animals↗
PubMed1996

Plasma neuropeptide Y in patients with major depressive disorder.

It has been suggested that neuropeptide Y (NPY) is involved in the pathophysiology of depression. Plasma peptide-rich fraction from patients with major depressive disorder and control subjects was eluted with high performance liquid chromatography (HPLC), followed by radioimmunoassay of NPY. The screening patterns of the NPY-like immunoreactivity in 50 fractions eluted by HPLC from the plasma peptide-rich fraction were different between the two groups. The values of NPY in the 16 controls and the 14 patients were 427 +/- 38 and 310 +/- 27 fmol/ml plasma (P < 0.05), respectively. These results suggest that impaired metabolism of plasma NPY and the reduced plasma NPY in patients with major depressive disorder could be involved in the pathogenesis or pathophysiology of major depressive disorder.

Adult↗
PubMed1996

[The practical theory of occupational health planning: Part One--The theoretical background of the target population setting and needs assessment procedures (OPST research report 2)].

The OPSS is an 8 stage program which was developed as a practical tool for occupational health services planning. This paper examines the theoretical aspects of the first two stages. The OPSS is a planning tool with a theoretical grounding in OHP (The practical theory of Occupational Health Planning). The target population setting has two functions. The first is to establish the physician's first-hypothesis to design a program. The other is deciding the group which has an occupational health problem in a company. The Needs Assessment helps to clarify the physician's hypothesis, which may be weak due to the limited knowledge of various demands of the employees and senior management. On the other hand, the risks and needs vary according to what kind of expert looks at a situation. To date, occupational physicians have been limited to their medical background in determining only risks and needs. However, understanding the various stakeholders in a particular environment means that any project will be more relevant to all concerned. Another limitation of the occupational physicians hypothesis can be the lack of objective data to support it. This makes it difficult to persuade senior management to sign on to a program. The Needs Assessment procedure with OHQ steps is useful in a number of ways. The Observation step allows for finding risks and needs from various situations in the company from the occupational physician's viewpoint (prehypothesis setting). Hearing is for understanding the subject's demands and finding common themes in the company (final hypothesis setting). Finally, the questionnaire step is for providing objectivity of these common themes and quantitative data for the next Priority Setting procedure. The BITOP (Budget, Information, Time, Order, key Person) has been proposed as a way to diagnose the structural and functional aspects of an organization's procedures. Budget tracks the financial flow through the organization, while Information identifies key information sources. Time helps to understand the reaction speeds of a company against environmental changes in the business community. Order looks at the flow of information from senior management through strategic gatekeepers. Understanding this flow helps the occupational physician to identify specific issues at various levels of the organization. Finally, key Person looks at the flow of information up through the organization, and identifies which key executives the occupational physician needs cooperation from in order for the project to be approved and successful. The above two procedures are essential tasks for insuring that an occupational physician can effectively implement a project that identifies what is necessary for the company and what the company wants to do, and works effectively within the organizational structure.

Health Planning↗
PubMed1996

Lipid abnormalities of erythrocyte membranes in hemodialysis patients with chronic renal failure.

Lipids in erythrocyte membranes from 16 hemodialysis patients and 16 healthy volunteers were studied using gas chromatographic mass spectrometry. 7-keto cholestadiene was first reported in this study. The ratios of 7-keto cholestadiene to cholesterol, the ratios of arachidonate to cholesterol and the ratios of dochosahexanate to cholesterol in peak heights of chromatograms were measured in both groups as the markers of lipid peroxidation. Higher 7-keto cholestadiene/cholesterol ratios and lower arachidonate/cholesterol and dochosahexanate/cholesterol ratios were significantly observed in hemodialysis patients compared with healthy subjects. Our results are evidence that hemodialysis patients are exposed to much oxidative stress. It has been suggested that, during hemodialysis, leukocytes are activated by contract with non-physiological surfaces of the blood line tubing and produce oxygen free radicals. Oxygen free radicals attach cholesterol, arachidonate and dochosahexanate to produce lipid peroxides. In this study, this cell activation may be responsible for the increased lipid peroxidation of hemodialysis patients, 7-Keto cholestadiene, arachidonate and dochosahexanate can be used as markers of lipid peroxidation in hemodialysis patients.

Adult↗
PubMed1996

Distribution of the mRNA for a pituitary adenylate cyclase-activating polypeptide receptor in the rat brain: an in situ hybridization study.

The distribution of the mRNA for a pituitary adenylate cyclase-activating polypeptide (PACAP) receptor (PACAP-R) was examined in the rat brain, and also in the hypophysis and pineal gland, by in situ hybridization with a specific 35S-labeled riboprobe which was generated from a rat PACAP-R cDNA clone. In the brain, expression of PACAP-R mRNA was most prominent in the periglomerular and granule cells of the olfactory bulb, granule cells of the dentate gyrus, supraoptic nucleus, and area postrema. The expression was also intense in the piriform, cingulate, and retrosplenial cortices, pyramidal cells in CA2, non-pyramidal cells in CA1-CA3, neuronal cells in the hilus of the dentate gyrus, lateral septal nucleus, intercalated amygdaloid nucleus, anterodorsal thalamic nucleus, most of the midline and intralaminar thalamic nuclei, many regions of the hypothalamus, dorsal motor nucleus of the vagus nerve, hypoglossal nucleus, and lateral reticular nucleus. No significant expression was detected in the mitral and tufted cells in the olfactory bulb, pyramidal cells in CA1 and CA3, posterior nuclear group of the thalamus, dorsal lateral geniculate nucleus, and Purkinje, Golgi, and granule cells in the cerebellar cortex. Moderate-to-weak expression was further observed in many other regions of the brain. In the cerebellar cortex, presumed Bergmann glia cells showed moderate expression. In the hypophysis, the expression was moderate in the anterior lobe, and weak to moderate in the posterior lobe; no significant expression was observed in the intermediate lobe. In the pineal gland, the expression was very weak, if any. Thus, the expression of PACAP-R was detected not only on neuronal cells but also on some particular glial cells. The present study has shown, for the first time, the exact site of PACAP-R expression in the brain and hypophysis. Although the functional significance of PACAP and PACAP-R in the brain still remains to be clarified, the present results are considered to provide some direction for future functional studies.

Animals↗
PubMed1996

Transgenic expression of L-gulono-gamma-lactone oxidase in medaka (Oryzias latipes), a teleost fish that lacks this enzyme necessary for L-ascorbic acid biosynthesis.

Transfer of the gene for L-gulono-gamma-lactone oxidase, the missing enzyme in L-ascorbic acid biosynthesis in scurvy-prone animals, into medaka (Oryzias latipes) was successfully done. The expression plasmid pSVL-GLO, carrying rat liver L-gulono-gamma-lactone oxidase cDNA, was microinjected into the cytoplasm of fertilized eggs during the one-cell stage. Four male F0 fish having the transgene in their germ cells came to maturity, and F1 progeny derived from one of the F0 fish possessed L-gulono-gamma-lactone oxidase activity, indicating that the transgene was functionally expressed in the fish. Genomic Southern blot analysis demonstrated that the transgene existed in both chromosome-integrated and extrachromosomal forms.

Animals↗
PubMed1996

cDNA cloning of a mouse pituitary adenylate cyclase-activating polypeptide receptor.

A cDNA clone for mouse pituitary adenylate cyclase-activating polypeptide (PACAP) receptor (PACAP-R) was obtained from the brain using reverse transcription-polymerase chain reaction (RT-PCR). The recombinant PACAP receptor expressed in COS cells bound PACAP with about 1000-times higher affinity than vasoactive intestinal polypeptide (VIP), and PACAP stimulated adenylate cyclase through the cloned PACAP receptor. The mouse PACAP receptor consists of 496 amino acids, contains seven transmembrane segments and has 98.4%, 93.0%, and 92.5% identity with the rat, bovine, and human PACAP-R, respectively.

Amino Acid Sequence↗