PubMed Health⌕ Search

Biomedical subjects

M Hashimoto

Publications and source records attributed to M Hashimoto.

At least 271 records · Page 15Linked to original sources
PubMed1999

Nonfunctioning islet cell carcinoma of the pancreas: an evaluation of seven patients who underwent resection followed by long-term survival.

Islet cell carcinoma of the pancreas is a rare, indolent malignancy associated with a higher resectability rate and better survival than ductal carcinoma. This retrospective study presents the results of surgical treatment for nonfunctioning islet cell carcinoma of the pancreas in seven patients diagnosed and treated at Kurume University Hospital. There were two men and five women, with an average age of 54 years. Of the five tumors, four were located in the head of the pancreas, and the other three tumors were located in the body or tail of the pancreas. Epigastric pain was frequently the primary clinical symptom. By the time of diagnosis, four of the patients had regional disease, one of whom had lymph node and liver metastases, and one, liver metastases. Another patients was found to have lymph node metastases intraoperatively. Only one of the patients died of recurrent cancer, 21 years after the original operation. All of the patients who had liver metastases at the time of initial surgical treatment are now living at home. Thus, we conclude that nonfunctioning islet cell carcinomas are slow-growing tumors with a good prognosis if the main tumors and metastatic lesions are removed.

Adult↗
PubMed1999

Nesidioblastosis with hyperinsulinemic hypoglycemia in adults: report of two cases.

We report herein the cases of two women, aged 34 years and 39 years, respectively, found to have hyperinsulinemic hypoglycemia after presenting with a history of episodes of temporary loss of consciousness, nausea, and fainting. Under the suspected diagnosis of insulinoma, localization procedures were carried out, but no tumor was found. In both patients, a definite gradient in insulin concentration was found in the pancreas by percutaneous transhepatic or intraoperative portal venous sampling, and a misdiagnosis of insulinoma of the pancreatic body was made. During exploratory laparotomy no tumor was palpable in the pancreas, and intraoperative ultrasonography showed no low echoic mass in the pancreas. A distal pancreatectomy was performed in both patients, and histopathological examination of the resected specimens revealed graded slight hyperplasia of the islet cells.

Adult↗
PubMed1999

Roles of CYP2A6 and CYP2B6 in nicotine C-oxidation by human liver microsomes.

Nicotine C-oxidation by recombinant human cytochrome P450 (P450 or CYP) enzymes and by human liver microsomes was investigated using a convenient high-performance liquid chromatographic method. Experiments with recombinant human P450 enzymes in baculovirus systems, which co-express human nicotinamide adenine dinucleotide phosphate (reduced form) (NADPH)-P450 reductase, revealed that CYP2A6 had the highest nicotine C-oxidation activities followed by CYP2B6 and CYP2D6; the Km values by these three P450 enzymes were determined to be 11.0, 105, and 132 microM, respectively, and the Vmax values to be 11.0, 8.2, and 8.6 nmol/min per nmol P450, respectively. CYP2E1, 2C19, 1A2, 2C8, 3A4, 2C9, and 1A1 catalysed nicotine C-oxidation only at high (500 microM) substrate concentration. CYP1B1, 2C18, 3A5, and 4A11 had no measurable activities even at 500 microM nicotine. In liver microsomes of 16 human samples, nicotine C-oxidation activities were correlated with CYP2A6 contents at 10 microM substrate concentration, whereas such correlation coefficients were decreased when the substrate concentration was increased to 500 microM. Contribution of CYP2B6 (as well as CYP2A6) was demonstrated by experiments with the effects of orphenadrine (and also coumarin and anti-CYP2A6) on the nicotine C-oxidation activities by human liver microsomes at 500 microM nicotine. CYP2D6 was found to have minor roles since quinidine did not inhibit microsomal nicotine C-oxidation at both 10 and 500 microM substrate concentrations. These results support the view that CYP2A6 has major roles for nicotine C-oxidation at lower substrate concentration and both CYP2A6 and 2B6 play roles at higher substrate concentrations in human liver microsomes.

Animals↗
PubMed1999

Genetic contribution of the BAT2 gene microsatellite polymorphism to the age-at-onset of insulin-dependent diabetes mellitus.

The BAT2 gene lies within the class III region of the major histocompatibility complex. We investigated the frequency of the BAT2 microsatellite alleles (BAT2) in 74 young-onset insulin-dependent diabetes mellitus (IDDM) patients, 51 adult-onset IDDM patients, and 85 normal control subjects, and assessed the associations among these BAT2 alleles, TNFa microsatellite alleles (TNFa), and HLA-DRB1 alleles. The frequency of the BAT2.9 allele was significantly increased in the young-onset IDDM patients (12.8 vs 4.1%, Pc=0.04896), whereas the frequency of BAT2.12 allele was significantly decreased in young-onset IDDM patients (0.0 vs 11.8%, Pc=0.00002) compared with control subjects. The BAT2.9 allele was strongly associated with TNFa9 in the young-onset IDDM patients, although no association was found between the BAT2.9 and HLA-DRB1 alleles. The BAT2.12 allele was strongly associated with TNFa13, and with DRB1*1502 in control subjects. These results suggest that the BAT2 microsatellite polymorphism is associated with the age-at-onset of IDDM and possibly with the inflammatory process of pancreatic beta-cell destruction during the development of IDDM. However, this association is not independent of TNFa polymorphisms.

Adolescent↗
PubMed1999

Predictive value of different hepatitis C serological assays in the treatment of chronic hepatitis C with interferon alpha.

In order to predict the complete response rate of natural interferon-alpha (nIFN-alpha) treatment in patients with chronic active hepatitis C, we examined the predictive value (PV) of different hepatitis C serological assays. We performed first generation (ver.1) and second generation (ver.2) hepatitis C virus (HCV) branched DNA-probe assays (bDNA-probe), HCV core protein assay (core protein), HCV Amplicor Monitor assay (amplicor monitor), and HCV competitive polymerase chain reaction (competitive PCR) assay, using serum samples collected immediately before initiation of treatment. For each marker, we studied, in patients stratified by serological group (Gr), which predictive value (PV) of the HCV titers showed association with the therapeutic effect. In 59 Gr 1 patients, complete response to nIFN-alpha treatment was predicted from the following PVs for each marker: 0.5 Meq/ml or less (odds ratio 11.7: P = 0.0010) with ver.1, 1.0 Meq/ml or less (odds ratio 5.3; P = 0.0119) with ver.2 of the bDNA-probe, 50 pg/ml or less (odds ratio 10.3; P = 0.0062) with core protein, 200 x 10(3) copy/ml or less (odds ratio 7.8; P = 0.0031) with amplicor monitor, and 10(4) copy/ml or less (odds ratio 6.2; p = 0.8395) with competitive PCR. In 27 Gr 2 patients, the PV for each marker indicating complete response was as follows: There was no relationship between PV and therapeutic effect with ver.1 of the bDNA-probe, while the PVs for the other markers were 0.2 Meq/ml or less (odds ratio 2.2; P = 0.3788) with ver.2, 20 pg/ml or less (odds ratio 5.6; P = 0.0597) with core protein, 400 x 10(3) copy/ml or less (odds ratio 4.0; P = 0.2965) with amplicor monitor, and 10(5.5) copy/ml or less (odds ratio 29.2; P = 0.0096) with competitive PCR. Our findings showed that complete response to the treatment may be predicted using the appropriate PV for each marker.

Adult↗
PubMed1999

Gastric enterochromaffin-like-cell tumor with liver and splenic metastases.

We report a patient with gastric enterochromaffin-like-cell tumor with liver and splenic metastases. He was 68 years old and presented with major complaints of epigastric pain and weight loss. Under the diagnosis of gastric carcinoma with liver metastasis, total gastrectomy with splenectomy and lateral segmentectomy of the liver was performed. Intraoperative findings resulted in a diagnosis of adenocarcinoma T3N2P0H1, in stage IVa. Histological examination of the resected specimens showed a well differentiated neuroendocrine carcinoma (enterochromaffin-like-cell tumor) with liver and splenic metastasis which demonstrated high-grade lymphatic and vascular invasion. There was no lymph node metastasis. The tumor cells in the stomach, liver and spleen were immunoreactive for chromogranin A and Grimelius--positive. We review the literature, as well as presenting this case report.

Aged↗
PubMed1999

Enzyme-linked immunosorbent assay to detect hepatitis C virus serological groups 1 to 6.

By conventional serological grouping methods, it is possible to determine hepatitis C virus (HCV) serological groups for genotypes 1a, and 1b, and genotypes 2a, and 2b, but not for other genotypes, i.e., 3a, 3b, 4a, 5a, and 6a. In this study, we attempted to serologically group HCV with the Murex HCV serotyping 1 to 6 assay (Murex Diagnostics, Kent, UK), using an enzyme-linked immunosorbent assay (ELISA) based on genotype-specific peptides from the NS4 region. The subjects of this study were 365 patients infected with HCV of genotype 1a, 1b, 2a, 2b, 3a, or 3b. The sensitivity of the assay was 100% in patients with genotype 1a, 82.7% in those with 1b, 68.5% in those with 2a, 84.2% in those with 2b, 50.0% in those with 3a, and 76.5% in those with genotype 3b. The overall sensitivity was 78.4%. The specificity of the assay was 100% in the subjects with genotype 1a, 98.8% in those with 1b, 98.4% in those with 2a, 96.9% in those with 2b, 100% in those with 3a, and 100% in those with genotype 3b. The overall specificity was 98.6%. The concordance of the assay was 100% in subjects with genotype la, 81.7% in those with 1b, 67.4% in those with 2a, 81.6% in those with 2b, 50.0% in those with 3a, and 76.5% in those with genotype 3b. The overall concordance was 77.5%. We believe it would be better to serotype with the Murex HCV serotyping 1 to 6 assay, if other than serological group (Gr) 1 or Gr 2 is suspected in particular ethnic groups or in subjects with an indeterminate result with the Immucheck HCV Gr assay (Kokusai, Kobe, Japan), assuming that the genotype must be other than 1a, 1b, 2a, or 2b.

Enzyme-Linked Immunosorbent Assay↗
PubMed1999

Effects of eicosapentaenoic acid and docosahexaenoic acid on plasma membrane fluidity of aortic endothelial cells.

We investigated the relative effects of n-3 eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) on the plasma membrane fluidity of endothelial cells (EC) cultured from the thoracic aorta by determining fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its cationic derivative trimethylamino-DPH (TMA-DPH). Fluidity assessed by TMA-DPH demonstrated no significant differences in plasma membranes of vehicle (dimethyl sulfoxide; DMSO)-, EPA-, and DHA-treated EC. Plasma membrane fluidity assessed by DPH polarization, however, was significantly higher in the order of DHA > EPA > DMSO. Total cholesterol content decreased significantly by 28.4 and 15.9% in the plasma membranes of DHA- and EPA-treated cells, respectively. Total phospholipid content remained unaltered in the plasma membranes of the three groups of cells; however, the molar ratio of total cholesterol to phospholipid decreased significantly only in the membranes of DHA-treated EC. The unsaturation index in the plasma membranes of EPA- and DHA-treated cells increased by 35.7 and 64.3%, respectively, compared with that in the plasma membranes of control cells. The activities of catalase and glutathione peroxidase in the whole-cell homogenates, and levels of lipid peroxides in either the whole-cell homogenates or in plasma membrane fractions were not altered in EPA- or DHA-treated EC. These results indicate that the influence of DHA is greater than that of EPA in increasing plasma membrane fluidity of vascular EC. We speculate that the greater effect of DHA compared to EPA is due to its greater ability to decrease membrane cholesterol content or the cholesterol/phospholipid molar ratio, or both, and also to its greater ability in elevating the unsaturation index in the plasma membranes of EC.

Animals↗
PubMed1999

Clinical findings in a patient with spontaneous arteriovenous fistulas of the orbit.

PURPOSE: To report clinical and radiologic findings of a patient with spontaneous arteriovenous fistulas of the orbit. METHOD: Case report. RESULTS: A 73-year-old woman was initially examined with a 1-year history of mild proptosis of the right eye. She had no history of trauma. Neuro-ophthalmologic examination disclosed dilatation of conjunctival vessels, increased intraocular pressure, mild proptosis and bruit in the right eye, and ocular signs suggestive of carotid-cavernous sinus fistulas or orbital arteriovenous malformations. The patient exhibited dilation of the superior ophthalmic vein in enhanced computed tomography of the orbit. Selective cerebral angiography disclosed communications between branches of both ophthalmic and facial arteries and the superior ophthalmic vein in the orbit. CONCLUSION: Arteriovenous fistulas of the orbit must be considered in the differential diagnosis of carotid-cavernous sinus fistulas and arteriovenous malformations, although they are quite rare.

Aged↗
PubMed1999

Topless optic disk syndrome without maternal diabetes mellitus.

PURPOSE: To describe four cases of topless optic disk syndrome without maternal diabetes mellitus. METHOD: Four patients had incidentally discovered inferior visual field defects. RESULTS: Ophthalmoscopic examinations in all four patients disclosed superiorly displaced entrances of the central retinal artery and thinning of the superior peripapillary nerve fiber layers. One patient had a superior peripapillary crescent with pallor of the superior disk. These clinical findings were consistent with a diagnosis of superior segmental optic hypoplasia, the topless disk. None of the patients had mothers who had diabetes. CONCLUSIONS: The topless optic disk syndrome can occur in the absence of maternal diabetes mellitus.

Adult↗
PubMed1999

H-magnetic resonance spectroscopy of retrobulbar tissue in Graves ophthalmopathy.

PURPOSE: Accumulation of glycosaminoglycans in the orbit may play an important role in the development of Graves ophthalmopathy. Therefore, it might be clinically useful to evaluate the concentration of glycosaminoglycans in the orbit in patients with Graves disease. We investigated the concentration of glycosaminoglycans in retrobulbar tissue using in vivo 1H-magnetic resonance spectroscopy. METHODS: A model solution of 1% chondroitin sulfate (one of the components of the glycosaminoglycans complex) was initially examined using 1H-magnetic resonance spectroscopy, and the resonance of chondroitin sulfate was identified. 1H-magnetic resonance-spectroscopy spectra of retrobulbar tissue were obtained in 16 normal volunteers (28 eyes) and 23 patients with Graves ophthalmopathy (36 eyes). The 1H-magnetic resonance spectroscopy spectrum of chondroitin sulphate in the retrobulbar in vivo tissue was identified by assignments through lineshape comparisons of spectra of the model solutions in vitro and the retrobulbar tissue in vivo. Chondroitin sulphate-peak/H2O-peak ratios were calculated. To verify the results of in vivo 1H-magnetic resonance spectroscopy, retrobulbar tissue samples from five patients, who underwent orbital decompression surgery, were tested for reactivity to chondroitin sulfate proteoglycan by enzyme-linked immunosorbent assay (ELISA). RESULTS: Multiple peaks, with a large peak at 5.24 ppm, were observed in 1H-magnetic resonance spectroscopy spectra of the model solution. A peak at 5.24 ppm was also observed in spectra of the retrobulbar tissue in all of the normal subjects and the patients. The mean value of the 5.24 ppm-peak/H2O-peak ratio was 0.1781 (SD = 0.0498, range, 0.0775 to 0.2282) in the normal subjects and 0.2874 (SD = 0.1357, range, 0.1405 to 0.7377) in the patients. The 5.24 ppm-peak/H2O-peak ratios were significantly increased in the patients with Graves ophthalmopathy (P < .01). The 5.24 ppm-peak/ H2O-peak ratio was correlated with the chondroitin sulphate concentration in retrobulbar tissue samples as evaluated by ELISA (r = .69). CONCLUSIONS: This study suggests that 1H-magnetic resonance spectroscopy of the retrobulbar tissue allows us to estimate the concentration of chondroitin sulphate proteoglycan in the retrobulbar tissue. 1H-magnetic resonance spectroscopy of the retrobulbar tissue may be a new clinical tool for the evaluation of Graves ophthalmopathy.

Adolescent↗
PubMed1999

Maximal period of cryopreservation with the Bicell biofreezing vessel for rat tracheal isografts.

OBJECTIVE: The maximal period of cryopreservation for the trachea is still unsolved. We assessed the maximal period of cryopreservation using the Bicell biofreezing vessel as an easy and cheap slow-freezing instrument for viable tracheal grafts in 95 rats. METHODS: Each isograft was harvested from 17 donor rats, immersed in the preservative solution, and stored in a Bicell device in a deep freezer at -80 degrees C. The tracheal isografts were then randomly assigned to 9 groups according to cryopreservation periods ranging from 0 to 12 months. Included in the 9 groups were 2 subgroups (n = 6 per subgroup) that were observed immediately after being thawed and 1 month after heterotopic transplantation into the omentum after being thawed. Four subgroups (n = 6 per subgroup) were added according to the cryopreservation period for 1, 3, 6, and 12 months to evaluate the graft morphology 3 months after being thawed and transplanted heterotopically. RESULTS: A prolonged period of cryopreservation had a degenerative effect on both the epithelium and cartilage. One month after transplantation, degeneration was more pronounced in the cartilage than in the epithelium, as characterized by the viable chondrocyte ratio and the epithelial score of isografts undergoing cryopreservation for more than 9 months. Three months after transplantation, the morphology of the epithelium and cartilage in isografts undergoing cryopreservation for less than 3 months was better preserved, whereas the morphology of both deteriorated in isografts undergoing cryopreservation for more than 6 months. CONCLUSIONS: We conclude that the permissible period of cryopreservation to maintain tracheal isograft viability in this simple system using a Bicell biofreezing vessel is 3 months.

Animals↗
PubMed1999

Association of age-related decrease in platelet membrane fluidity with platelet lipid peroxide.

The influence of age on platelet lipid peroxide (LPO), platelet membrane fluidity and the composition of fatty acid was investigated in female Wistar rats widely ranging in age from 14 to 720 days old. LPO levels were significantly higher (p<0.05) in the platelets of upper age groups than in those of lower age groups, showing a significantly positive correlation with age (r=0.84, p<0.0001). Membrane fluidity, assessed by 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence polarization, was significantly reduced with age. The composition of fatty acid demonstrated an age-related elevation (p<0.05) in the unsaturation index. The rises in the LPO levels revealed a significantly positive correlation with DPH-polarization (r=0.73, p<0.0001). Thus our results suggested that the age-related deterioration of platelet membrane fluidity, despite a significant elevation in the unsaturation index, was due to the age-related higher basal levels of LPO in platelets.

Aging↗
PubMed1999

Preparation of specific antisera to 15alpha-hydroxyestrogens.

The synthesis of haptens of 15alpha-hydroxyestrone, 15alpha-hydroxyestradiol, and 15alpha-hydroxyestriol (estetrol) was undertaken, to obtain specific antisera required for enzyme immunoassay. 3-(1-Carboxypropyl) ethers of these 15alpha-hydroxyestrogens were prepared and conjugated with bovine serum albumin and horseradish peroxidase. The specificity of antisera elicited against bovine serum albumin conjugates was checked by the enzyme immunoassay by using horseradish peroxidase-labeled antigen, and proved to be satisfactory in terms of cross-reactivities to related compounds.

Animals↗
PubMed1999

Left atrial endocardium and prostacyclin.

In patients with rheumatic mitral stenosis, intracardiac thrombi are found mostly, for reasons still unknown, in the left atrium. We compared the release of PGI2 from the endocardium of the left atrium with that of the right ventricle and from the endothelium of the pulmonary arteries. Endocardial endothelial cells (EECs) were isolated from right ventricles (RV) and left atrial appendages (LAA) of porcine hearts, and vascular endothelial cells (VECs) from pulmonary arteries (PA) were obtained from the same animals. Cultured EEC and PA-VEC monolayers were placed in a pressure loading apparatus and incubated for 30 min under various pressures. After incubation, the supernatants were sampled and the 6-keto-PGF1 alpha contents measured. PGI2 release from LAA-EEC was much less than from RV-EEC or from PA-VEC. Moreover, transmural pressure did not enhance PGI2 release from LAA-EEC, although it did from RV-EEC and PA-EEC in a pressure-dependent manner. These results may explain why the left atrium is a common site for intracardiac thrombus formation in patients with mitral valve disease.

6-Ketoprostaglandin F1 alpha↗
PubMed1999

Dopa-producing astrocytes generated by adenoviral transduction of human tyrosine hydroxylase gene: in vitro study and transplantation to hemiparkinsonian model rats.

Astrocytes secreting a large amount of 3,4-dihydroxyphenylalanine (dopa) were generated by adenoviral transduction of the human tyrosine hydroxylase (TH) gene. After characterizing in vitro, the effect of transplantation of these astrocytes to the striatum of hemiparkinsonian model rats was investigated. Subconfluent cortical astrocytes were infected by replication-defect adenovirus type 5 carrying the human TH-1 gene or the LacZ reporter gene under the promoter of the glial fibrillary acidic protein (AdexGFAP-HTH-1, AdexGFAP-NL-LacZ). Dopa secretion was not evident at 3 days after the transduction of the HTH-1 gene but it increased from 7 days up to at least 4 months. The secretion was substrate (tyrosine)-dependent, and was enhanced by loading tetrahydrobioputerin (BH4) concentration-dependently. One-third of the hemiparkinsonian model rats, that were transplanted the HTH-1 gene-transduced astrocytes or introduced the direct injection of the viral vector to the striatum, showed a reduction of methamphetamine-induced rotations for at least 6 weeks. Apomorphine-induced rotation was decreased to the 50% level of the control's, but the reduction was obtained equally by the transplantation of HTH-1 gene-transduced or LacZ reporter gene-transduced astrocytes, or by the introduction of HTH-1 or LacZ gene carrying adenovirus. Treatment with FK506 for 3 weeks improved the late-phase apomorphine-induced rotations following the introduction of the HTH-1 gene carrying adenovirus. Histological examination revealed that, in animals that showed a reduction of methamphetamine-rotation, the TH positive astrocytes-like cells were distributed widely in the host striatum for at least 4 weeks. The number of TH positive astrocytes-like cells and their immunoreactivity decreased after 6 weeks when OX-41 positive microglias/macrophages were infiltrated. Data indicate that the adenoviral transduction of the human TH gene to astrocytes and its introduction to the striatum is a promising approach for the treatment of Parkinson's disease. However, the further technical improvements are required to optimize the adenoviral gene delivery, such as the control of viral toxicity and the regulation of the immune response.

Adenoviridae↗
PubMed1999

Increased levels of aldose reductase in peripheral mononuclear cells from type 2 diabetic patients with microangiopathy.

Aldose reductase (AR) protein was measured in peripheral mononuclear cells (PMCs) from 55 patients with type 2 diabetes by a two-site ELISA using anti-human AR monoclonal antibody. AR levels did not correlate with age, duration of diabetes, and HbAlc. Furthermore, no significant differences were found in AR levels between the patients and healthy subjects. Thirty seven patients had at least one of diabetic microangiopathy; retinopathy, neuropathy, or nephropathy. AR levels were significantly higher in the patients with microangiopathy than in those without it (52.3 +/- 15.7 vs. 43.0 +/- 15.2 ng/10(6) cells, P < 0.05). The patients with neuropathy had significantly higher AR levels than those without neuropathy (53.7 +/- 15.8 vs. 42.7 +/- 14.3 ng/l0(6) cells, P < 0.05). The same result applied to the patients with retinopathy (54.5 + 15.4 vs. 44.6 +/- 15.3 ng/10(6) cells, P < 0.05). The AR levels in the patients with nephropathy tended to give a higher value than those without it. However, there were no significant differences between the two (53.9 +/- 3.6 vs. 46.4 +/- 2.6 ng/10(6) cells, NS). These results indicate that AR levels in PMCs from type 2 diabetic patients are associated with the presence of microangiopathy. The measurement of AR proteins in PMCs with this ELISA system is a useful tool for the clinical study of diabetic complications, and would increase our understanding of the pathogenesis of the disease.

Adult↗