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Biomedical subjects

S Hara

Publications and source records attributed to S Hara.

At least 145 records · Page 8Linked to original sources
PubMed1999

Proliferation of parathyroid cells negatively correlates with expression of parathyroid hormone-related protein in secondary parathyroid hyperplasia.

BACKGROUND: Parathyroid hormone-related protein (PTHrP) is now suspected to act as an autocrine or paracrine regulator of cell growth or differentiation, although it was originally reported as a hypercalcemic substance in malignancies. This study was performed to assess the relationship between PTHrP expression and cell proliferation in human parathyroid glands. METHODS: The localization of PTH and PTHrP was studied in 42 samples of hyperplastic parathyroid from 14 long-term hemodialysis cases with immunohistochemistry and in situ hybridization. Results were compared with proliferative activity (proliferating cell nuclear antigen index: counts of proliferating cell nuclear antigen-positive cells/100 cells). The localization of the PTH/PTHrP receptor was also examined. Ten normal glands were studied as controls. RESULTS: In hyperplasia, cells positive for PTH, PTHrP, or both were observed immunohistochemically. The areas expressing PTHrP mRNA completely coincided with those positive for PTHrP immunohistochemically. Oxyphilic or transitional oxyphilic cells were consistently positive for PTHrP. PTH/PTHrP receptors were located in the cytoplasmic membrane in most parathyroid cells. Proliferating cell nuclear antigen-positive cells were rare in normal glands with an index of 0. 22 +/- 0.09 (mean +/- sem). They were significantly increased in hyperplastic cases but less for PTHrP-positive than for -negative cells (1.25 +/- 0.16 as compared with 7.80 +/- 0.52; P < 0.0001). CONCLUSION: The observed low level of proliferation of PTHrP-positive cells suggests a functional role for PTHrP as a possible growth suppressor in the human parathyroid.

Adult↗
PubMed1999

Fructose 1,6-bisphosphate aldolase is a heparin-binding protein.

Proteins with affinity to heparin under physiological conditions were isolated from bovine cerebral cortex. First, the extract of cerebral cortex was applied to a chondroitin polysulfate column under physiological conditions. Then, the pass-through fraction was applied to a heparin column. Among the bands on SDS polyacrylamide gel electrophoresis of the fraction bound to the heparin column, the major one was identified as fructose 1,6-bisphosphate aldolase (FPA), a cytosolic enzyme involved in the glycolytic pathway. The results indicated that FPA is a heparin-binding protein which exhibits no affinity to chondroitin polysulfate. The results of affinity chromatographies revealed that FPA binds to intact heparin and modified heparins desulfated at C2 OH of the iduronic acid residue or at C6 OH or C2 NH2 of the glucosamine residue. When 6-O-desulfated heparin was employed as the affinity ligand, a single peak having FPA activity was isolated from the extract of bovine cerebral cortex. By further Mono Q chromatography and Superdex gel-filtration, five isoenzymes were purified with more than 50% recovery. These isoenzymes were identified as FPA A4, A3C1, A2C2, A1C3, and C4 by native electrophoresis with and without 4 M urea and subsequent amino acid sequence analysis. The use of 6-O-desulfated heparin affinity chromatography thus facilitated the purification of FPA.

Animals↗
PubMed1999

Clinical outcome of high-dose chemotherapy combined with peripheral blood stem cell transplantation for male germ cell tumors.

Peripheral blood stem cell transplantation (PBSCT) is widely performed currently instead of bone marrow transplantation (BMT) because bone marrow reconstruction is better and the procedure is less invasive. We applied 26 courses of high-dose chemotherapy (1250 mg/m2 of carboplatin, 1500 mg/m2 of etoposide and 7.5 g/m2 of ifosfamide) to 14 male patients with germ cell tumors. Eleven patients underwent high-dose chemotherapy as induction after two to three courses of conventional BEP therapy. The remaining three patients had recurrent disease after conventional chemotherapies. Peripheral blood stem cells were harvested during previous chemotherapy and sufficient CD34+ cells were harvested for transplantation. Although all patients had grade 4 hematotoxicity, the white blood cell count recovered to more than 1000/microl within 8-11 days after PBSCT. No treatment-related death was found. Nine of 14 patients (64.3%) remain disease free at 18 months of median follow up time (range 12-60). We conclude that high-dose chemotherapy is a safe and effective means of treating advanced or refractory germ cell tumors in male patients.

Adult↗
PubMed1999

Gene transfer of human prostacyclin synthase prevents neointimal formation after carotid balloon injury in rats.

BACKGROUND AND PURPOSE: A disordered proliferative process in the vascular wall is thought to underlie the pathogenesis of restenosis after percutaneous transluminal angioplasty and carotid endarterectomy. A growth inhibitory property of overexpressed prostacyclin (PGI2) synthase (PGIS) was recently implicated in the pathological proliferation of vascular smooth muscle cells (VSMC) in vitro. Here, we investigated the effects of increased PGI2 synthesis on the pathological proliferation of VSMCs. METHODS: The cDNA encoding human PGIS was transfected into endothelium-denuded rat carotid arteries after arterial balloon injury with the use of hemagglutinating virus Japan (HVJ). HVJ liposome vector complex without PGIS cDNA was used for vehicle control. The level of 6-keto PGF1alpha, a stable hydrolyzed metabolite of PGI2, the histological distribution of the immunoreactivity for human PGIS and the ratio of neointimal/medial area were analyzed. RESULTS: In the analyses of 6-keto PGF1alpha, the level in the carotid arteries was significantly elevated 3 days after PGIS expression-vector transfection compared with that in the arteries after vehicle transfection. Seven days after human PGIS expression-vector transfection, the PGIS cDNA-transfected neointimal cells were strongly positive for human PGIS immunoreactivity in 81% sections examined. Fourteen days after the injury, the ratio of neointimal/medial area was 1.2+/-0.4 in the PGIS expression-vector transfected group, which was significantly smaller than that of the vehicle control group, 1.7+/-0.5; P<0.01. CONCLUSIONS: It was thus demonstrated that the gene transfer of human PGIS expression-vector into rat carotid arteries resulted in the increased production of human PGI2 in the vascular wall, the expression of human PGIS in the developing neointima and significantly inhibited the neointimal formation generated after balloon injury.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

Determination of valproic acid in human serum by high-performance liquid chromatography with fluorescence detection.

A simple and highly sensitive high-performance liquid chromatographic method is described for the determination of valproic acid in human serum. The method is based on the direct derivatization of serum sample with 6,7-methylenedioxy-1-methyl-2-oxo-1,2-dihydroquinoxaline-3-ylpr opionohydrazide. The derivatization reaction proceeds in aqueous solution in the presence of pyridine and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide at 37 degrees C. The resulting derivatives were separated on a reversed-phase column (YMC Pack ODS-A) with isocratic elution and were fluorimetrically detected at 440 nm with excitation at 365 nm. The detection limit (signal-to-noise ratio=3) for valproic acid added to serum sample was 0.1 microg (700 fmol)/ml serum sample (2.3 fmol on column). The method was applied to determine the unbound- and total-valproic acid levels in the serum obtained from three healthy volunteers after oral administration of the drug (600 mg).

Adult↗
PubMed1999

[A case of rheumatoid arthritis with bucillamine-induced myasthenia gravis treated by immunoadsorption therapy].

We report a case of 48-year old female with rheumatoid arthritis (RA) complicated with myasthenia gravis. In 1988, she was diagnosed of having RA, and several therapeutic drugs were administered, but her disease activity was in poor control. In July 1993, bucillamine (BU) was started at a dose of 100 mg/day, and her arthritis subsided. However, in October 1996, she was admitted with a rapidly progressive ptosis and double vision in the left eye, which became prominent in the evening. Because serum concentration of the antibody to acetylcholine receptors (AchR Ab) was elevated at 12.6 nmol/l, and the ptosis was reversed immediately after a tensilon test, ocular type myasthenia gravis (MG) was diagnosed and it was thought to have been induced by BU. Immunoadsorption therapy was started after discontinuation of this drug, and was continued for 6 months, resulting in improvement of neurological symptoms and decrease in AchR Ab level. MG has not recurred since. Although several cases of D-penicillamine (DP) induced MG are reported, only two cases are reported which were induced by BU, sulfhydryl compound which has a structure similar to DP. Since BU has been widely used as one of the disease modifying anti-rheumatic drugs in Japan, MG induced by this drug should be paid attention as one of the adverse effects.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

Effects of rolipram and cilostamide on renal functions and cyclic AMP release in anesthetized dogs.

The present study was undertaken to examine whether phosphodiesterases III and IV regulate renal cAMP level and whether inhibition of these enzymes influences renal functions in anesthetized dogs. The intrarenal arterial infusion of rolipram (0.1, 0.3, and 1 microgram/kg/min), a selective phosphodiesterase IV inhibitor, increased renal blood flow, glomerular filtration rate, urine flow rate, and urinary Na+ excretion with elevating arterial and renal venous plasma cAMP concentrations and urinary cAMP excretion. However, cilostamide (0.1, 0.3, and 1 microgram/kg/min), a selective phosphodiesterase III inhibitor, did not affect the values of these parameters. Indomethacin (3 mg/kg i.v. bolus and 1 mg/kg/min i.v. infusion), a cyclooxygenase inhibitor, reduced the basal arterial and renal venous plasma cAMP concentrations and blunted the rolipram-induced elevation of cAMP concentrations and urinary cAMP excretion. The effects of rolipram on renal hemodynamics and urine formation were attenuated in the presence of indomethacin. These results suggest that in the dog kidney in vivo, 1) phosphodiesterase IV, but not phosphodiesterase III, participates in degradation of cAMP and 2) the inhibition of phosphodiesterase IV enhances glomerular filtration and urinary Na+ excretion, the responses of which depend in part on indomethacin-susceptible (prostaglandin-mediated, probably) control of basal cAMP level.

Anesthesia, General↗
PubMed1999

[A case of true carcinosarcoma in bladder diverticulum].

We report a case of carcinosarcoma arising from a bladder diverticulum. A 71-year-old male was referred to our hospital for macroscopic hematuria. Two diverticula were identified in the left wall of the urinary bladder, one of which showed a broad-based tumor. The bladder tumor was resected using a transuretheral approach and the tumor was histologically diagnosed as leiomyosarcoma. The patient underwent partial resection of the bladder including the two diverticula and the tumor. Pathological examination revealed that the resected specimen was composed of three elements, transitional cell carcinoma (G3), squamous cell carcinoma, and leiomyosarcoma. Thus, the patient was diagnosed with carcinosarcoma. He died 5 months after surgery to remove the panperitonitis carcinomatosa. This case is the 38th reported case of bladder carcinosarcoma in Japan.

Aged↗
PubMed1999

Relative expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 in mouse renal cell carcinoma cells regulates their metastatic potential.

To clarify the significance of the balance between matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) in the progression of renal cell carcinoma, we transfected both the MMP-2 and TIMP-2 genes simultaneously into RenCa, a mouse renal cell carcinoma cell line that does not express detectable levels of either MMP-2 or TIMP-2 mRNAs, and established several clones with various MMP-2:TIMP-2 expression ratios. On the basis of the quantitative evaluation of the MMP-2: TIMP-2 mRNA expression ratio by Northern blot analysis, we selected a clone overexpressing MMP-2 alone (RenCa/M), a clone overexpressing TIMP-2 alone (RenCa/T), and two kinds of clones overexpressing both, i.e., one with a high (RenCa/MTh) and one with a low (RenCa/MTl) MMP-2: TIMP-2 ratio, to compare the tumor cell phenotypes. In an in vitro tumor cell invasion assay, the MMP-2:TIMP-2 ratios of the RenCa sublines were directly correlated with their invasive potential. The invasive abilities of the parental RenCa cells induced by conditioned media from RenCa sublines were also correlated with the MMP-2:TIMP-2 ratios of the sublines. The cell adhesion assay showed the inverse correlation between the MMP-2 expression levels in the sublines and their cell adhesion to several extracellular matrix components. Furthermore, when injected i.v. or into the renal subcapsule in syngeneic mice, RenCa sublines formed metastatic nodules in the lungs, and the number of nodules was correlated with the MMP-2:TIMP-2 ratio of each clone. In contrast, despite the growth-inhibitory effects of TIMP-2 overexpression, MMP-2 overexpression had no effect on either proliferation in vitro of RenCa sublines or on their growth as tumors in vivo. These results suggest that the MMP-2:TIMP-2 expression ratio is a critical factor in the invasion and metastasis of renal cell carcinoma.

Animals↗
PubMed1999

[A case of multiple early gastric cancer showing complete response to UFT-E after endoscopic mucosal resection].

A 78-year-old male underwent endoscopic mucosal resection for early gastric cancer (type II a) in the anterior wall of antrum. Follow-up endoscopy showed another early gastric cancer (type II c) in the posterior wall of cardia. He refused an operation. UFT-E 300 mg/day has been administered daily since then. After 6 months, a complete tumor response was observed. The patient has been in good health without any sign of relapse for 14 months after achievement of the complete response.

Adenocarcinoma↗
PubMed1998

Characterization of temperature rise of the brain and the rectum following intracerebroventricular administration of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate and kainate in rats.

Intracerebroventricular administration of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) or kainate caused a rise of the temperature of the brain and the rectum in urethane-anesthetized rats. An AMPA-kainate receptor antagonist, 6,7-dinitroquinoxaline-2,3-dione (DNQX), significantly suppressed the AMPA- and kainate-induced rises of brain and rectal temperatures. An N-methyl-d-aspartate receptor antagonist, MK-801, also suppressed the rises of the brain and rectal temperatures induced by AMPA or kainate, but the profiles of the suppressive effects of MK-801 were different between rats treated with AMPA and kainate. An antipyretic agent, indomethacin, completely suppressed the AMPA-induced rises of brain and rectal temperatures. Although indomethacin completely suppressed the kainate-induced rise of the rectal temperature as well, the brain temperature was still raised. These findings suggest that distinct mechanisms may be involved in the temperature rise of the brain and the rectum mediated through AMPA and kainate receptor stimulation.

Analgesics, Non-Narcotic↗
PubMed1998

Evidence of association of the ecNOS gene polymorphism with plasma NO metabolite levels in humans.

Nitric oxide (NO) synthesized by the vascular endothelium regulates mammalian blood vessels and other systems in humans. Recently, an endothelial nitric oxide synthase (ecNOS) gene polymorphism, the 27-bp repeat in intron 4 (ecNOS4), was reported to be related to the pathogenesis of coronary heart disease and terminal renal failure. We analyzed this polymorphism in a group of 413 healthy subjects, and measured their plasma nitrite and nitrate (NOx) levels. The frequency of the b allele was 89.8% , and the frequency of the a allele was 10.2%. The frequency of ecNOS4 b/b, ecNOS4 b/a, and ecNOS4 a/a in the healthy subjects in this study was 0.814 (n=336), 0.169 (n=70) and 0.017 (n=7), respectively. Using this polymorphism as a DNA marker, we found a strong association between the alleles of the ecNOS gene polymorphism and the plasma NOx levels. The basal NO metabolite levels were 28.8 micromol/L in subjects with ecNOS4 a/a, 31.4 micromol/L in those with ecNOS4 b/a, and 35.5 micromol/L in those with ecNOS4 b/b. The mean plasma NOx level of the subjects who were homozygous for the a allele was nearly 20% lower than in the subjects with the b allele. The plasma NOx level of the subjects with the a allele was 31.2+/-2.00 micromol/L, and significantly lower than the 35.5+/-0.93 micromol/L in those without the a allele (P <0.05). The results of this study indicate that the ecNOS4 gene locus may be responsible for variations in the genetic control of plasma NOx and that analysis of ecNOS4 gene polymorphism may be a useful tool for studying the relation between NO and diseases.

Adult↗
PubMed1998

Structural requirements of human tissue factor pathway inhibitor (TFPI) and heparin for TFPI-heparin interaction.

Heparin affinity chromatography of synthetic peptide fragments mimicking tissue factor pathway inhibitor (TFPI) indicated that the minimal heparin binding sequence consists of 12 amino acid residues located at the C-terminal tail. Within this minimal sequence, Arg-257 and Arg-259 appeared to contribute most significantly to interaction with heparin. Affinity chromatography of TFPI using immobilized heparin derivatives regiospecifically desulfated at O-6 of the glucosamine residue, N-2 of the glucosamine residue, and/or O-2 of the iduronic acid residue indicated that all the sulfate groups in heparin appeared to be required for TFPI-heparin interaction. Among them, however, the 6-O-sulfate groups appeared to make the largest contribution to the interaction, while the 2-O-sulfate groups contributed the least. In vitro experiments on the inhibition of factor Xa by TFPI enhanced with native and chemically modified heparins afforded similar results.

Amino Acid Sequence↗
PubMed1998

Selective deamidation of recombinant human stem cell factor during in vitro aging: isolation and characterization of the aspartyl and isoaspartyl homodimers and heterodimers.

During in vitro aging, deamidation of recombinant human stem cell factor produced in Escherichia. coli was detected by HPLC analysis and by the release of soluble ammonia. The deamidation rate is very slow in buffers at low pH or at low temperatures; however, the rate is significantly accelerated in alkaline buffers such as sodium bicarbonate in combination with elevated temperatures. HPLC isolation of various deamidated forms followed by peptide mapping and mass spectrometric analyses revealed that the deamidation involves Asn10 in the sequence -T9NNV- near the N-terminus of the protein. Following peptide mapping analysis, significant amounts of aspartyl and isoaspartyl peptides were identified, indicating the conversion of asparagine into both aspartate and isoaspartate residues. As a result of spontaneous association-dissociation of stem cell factor dimer, a total of five deamidated forms, including two homodimers and three heterodimers, were detected and isolated. Cell proliferation assays showed that two rhSCF heterodimeric species, derived from dimerization between isoaspartyl and other stem cell factor monomers, retain only approximately half of the biological activity. The homodimer with isoaspartic acid in place of Asn10 is 50-fold less potent, while the aspartyl homodimer, either isolated during deamidation experiments or recombinantly prepared by site-directed mutagenesis (e.g., N10D and N10D/N11D variants), exhibits higher activity than the standard molecule. In comparison, synthetic N10A and N10E variants, though missing the deamidation site, are significantly less active. All these variants lacking the Asn10 deamidation site are relatively more stable than those containing the asparagine residue. The results indicate that the biological function and chemical stability of stem cell factor are influenced by the nature of the residue at position 10.

Amides↗