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H Hoshi

Publications and source records attributed to H Hoshi.

At least 145 records · Page 8Linked to original sources
PubMed1996

Alterations of cytochrome P450-dependent monooxygenase activities in Eriocheir japonicus in response to water pollution.

Eriocheir japonicus, fresh-water crabs inhabiting rivers and estuaries in Japan, were investigated for cytochrome P450 (CYP)-dependent drug-metabolizing enzyme activities to see if these activities reflect the river pollution gradient. From the laboratory dose-response experiments, we found that the polycyclic aromatic hydrocarbon (PAH) 3-methylcholanthrene induced total CYP contents, ethoxycoumarin O-deethylase activity, and bunitrolol 4-hydroxylase activity in crab hepatopancreas. In the field studies, crabs collected from the river with the highest concentration of PAHs exhibited the highest levels of CYP, the highest activities of benzo[a]pyrene 3-hydroxylase, imipramine 2-hydroxylase, bunitrolol 4-hydroxylase, ethoxycoumarin O-deethylase, and the ability to metabolically activate benzo[a]pyrene, but erythromycin N-demethylase activity was not induced. The correlation between PAH levels and drug-metabolizing enzyme activities in female crabs were not as marked as in male crabs. The levels and activities of CYP did not appear to reflect the concentrations of organochlorines and polychlorinated biphenyl congeners (PCBs) studied in the fat of crab hepatopancreas.

Animals↗
PubMed1996

Cerebral perfusion imaging evaluates pharmacologic treatment of unilateral moyamoya disease.

Unilateral Moyamoya disease presents as unilateral stenosis or obstruction of the supraclinoid internal carotid artery, which causes cerebral hypoperfusion resulting in seizures or TIA-like attacks. In severe cases, surgical treatment is performed with superficial temporal artery-middle cerebral artery anastomosis. In mild cases, conservative management is the treatment of choice. Flunarizine is a calcium ion anti-blocking agent, whose primary effect is that the cerebral vessels have been used for the treatment of postcerebrovascular disorders. Recently, it has been suggested that flunarizine could be used to treat Moyamoya disease. This report documents the efficacy of flunarizine to improve regional cerebral perfusion in Moyamoya disease.

Brain↗
PubMed1996

Technetium-99m-sestamibi scintigraphy compared with thallium-201 in evaluation of thyroid tumors.

UNLABELLED: Technetium-99m methoxyisobutylisonitrile (MIBI) is a myocardial perfusion imaging agent that has been reported to effectively localize in various tumors (e.g., lung and thyroid carcinomas and osteogenic sarcoma). To determine its usefulness in thyroid tumors, we compared 99mTc-MIBI with 201TI imaging. METHOD: We evaluated 25 patients with thyroid tumors (papillary carcinoma in 11, follicular carcinoma in 2, follicular adenoma in 7, adenomatous goiter in 5). Fifteen metastatic lesions from differentiated thyroid carcinomas were also evaluated. Early (10 min after injection) and delayed images (120 min after injection) were obtained for both 99mTc-MIBI and 201TI scintigraphy. RESULTS: The early images showed very similar findings for both 99mTc-MIBI and 201TI. However, the delayed images showed that malignant tumors tended to retain more tracer agent than benign nodules. Marked retention was in 61.5% (8 of 13) of 201TI images and 53.8% (7 of 13) of 99mTc-MIBI images. For metastatic lesions from thyroid carcinomas, the findings for 99mTc-MIBI imaging were nearly identical to those for 201TI imaging. A slight difference in clarity was seen that may have been due to the effect of the 99mTc. CONCLUSION: Although 99mTc-MIBI scintigraphy does not have particularly good results in differentiating malignant from benign thyroid tumors, it may be useful in evaluating metastases or predicting recurrence because of its better imaging characteristics.

Adenocarcinoma, Follicular↗
PubMed1996

Susceptibility-weighted MR for evaluation of vasodilatory capacity with acetazolamide challenge.

PURPOSE: To investigate cerebral vasodilatory capacity by acetazolamide challenge in healthy subjects and in patients with chronic occlusive cerebrovascular disease by using susceptibility-weighted gradient-echo MR imaging. METHODS: Eight patients with chronic occlusive cerebrovascular disease and four healthy volunteers were studied with susceptibility-weighted MR imaging before and after intravenous administration of 1000 mg of acetazolamide. Signal intensities were measured as a function of time in several regions of interest defined on anatomic images. In all patients with chronic occlusive cerebrovascular disease, acetazolamide challenge and resting regional cerebral blood flow were also evaluated with single-photon emission CT (SPECT). RESULTS: In healthy volunteers, signal intensities began to increase 3 to 4 minutes after acetazolamide administration, with a continuous increase during the subsequent 10 minutes. The effect lasted for approximately 45 minutes after administration. In patients with chronic occlusive cerebrovascular disease, signal changes on susceptibility-weighted MR images of occluded areas with normal vasodilatory capacity on SPECT images did not differ from signal changes of nonocclusive areas. In those patients with changes that reflected diminished vasodilatory capacity, the MR images showed a lower percentage of signal changes after acetazolamide administration than those in normally perfused areas. CONCLUSION: Susceptibility-weighted MR imaging offers an alternative method for estimating vasodilatory capacity.

Acetazolamide↗
PubMed1996

Effect of 3-methylcholanthrene on bunitrolol metabolism. Kinetics and immunological studies on 4-hydroxylation of bunitrolol catalyzed by two species of cytochromes P450 in rat liver microsomes.

Effect of the induction of cytochrome P4501A1 with 3-methylcholanthrene (3-MC) treatment on kinetics of bunitrolol (BTL) 4-hydroxylase activity of rat liver microsomes was investigated. The relationship between the rate and BTL concentration showed monophasic kinetics (KM = 0.74 +/- 0.13 microM) when microsomes from untreated rats were used, whereas microsomes from 3-MC-treated rats showed biphasic kinetics (KM1 = 0.76 +/- 0.13, KM2 = 646 +/- 16 microM). Anti-cytochrome P450 (P450) BTL (P4502D subfamily) antiserum inhibited the reaction > 90% when low concentrations (approximately 10 microM) of BTL were used in both microsomes. However, at high BTL concentrations (approximately 2,000 microM), the inhibition was only up to a half of control in microsomes from 3-MC-treated rats, whereas in microsomes from untreated rats, the rates were suppressed > 90%. Kinetics observed in microsomes from 3-MC-treated rats changed to nearly monophasic, with a KM value corresponding to KM2. Anti-P4501A1 IgG, on the other hand, hardly inhibited the reaction conducted by liver microsomes from 3-MC-treated rats when substrate concentrations were low, whereas at higher concentrations, it inhibited up to 50%, resulting in a monophasic kinetics with a KM value corresponding to KM1. These results clearly indicate that the biphasicity of kinetics in BTL metabolism in liver microsomes from 3-MC-treated rats is caused by the involvement of two P450 species: P450 BTL and P4501A1 in the reaction. This is the first direct evidence to the theoretical hypothesis that the biphasic kinetics of the enzyme reaction is caused by the involvement of at least two enzymes with different kinetic parameters.

Animals↗
PubMed1996

[Normal distribution of CBF with advancing age measured by HMPAO SPECT].

SPECT with Tc-99m HMPAO was used to determine global and regional cerebral blood flow (CBF) in 52 healthy subjects ranging from 2 to 85 years old. These subjects were divided into six groups according to age. SPECT images were obtained using a three-headed gamma camera system equipped with low-energy ultra-high-resolution fan beam collimators (LEUHR-FAN). Absolute CBF values were estimated in 21 of 52 subjects using a Patlak plot technique. The SPECT images were obtained 5-10 minutes after the injection of 740MBq of Tc-99m HMPAO. A supercomputer system was used to reconstruct transverse section images at levels of 8, 32, 44 and 67 mm above the orbitomeatal line (2.7 mm thickness), and oblique transverse section images parallel to the temporal lobe (1.56 mm thickness). Lassen's linearization correction was applied. The average counts of four or five ROIs in eight regions were calculated. The cerebral to cerebellar activity ratio (C/C ratio) was estimated by dividing counts in the cerebral regions by those in the cerebellum. The interhemispheric differences in C/C ratios in the eight regions of all the groups were not significant. In elderly subjects there was a tendency for C/C ratios to decrease except in the thalamus and basal ganglia. Mean global CBF in 21 of 52 subjects was 49.3 +/- 10 ml/100g/min. A significant negative correlation was found between global CBF and advancing age (p < 0.05), particularly in males (p < 0.01).

Adolescent↗
PubMed1996

[A case of transient tic disorder with abnormal findings on 99mTc-HMPAO SPECT].

We report a case of transient tic disorder with abnormal findings on 99mTc-HMPAO SPECT. The patient was 5-year-old girl with vocal and motor tic. There was no evidence of structural abnormality on magnetic resonance imaging (MRI). Electroencephalogram (EEG) showed spikes and sharp waves on both frontal lobes and parietal lobes (left-side dominant). 99mTc-HMPAO SPECT demonstrated focal regions of hyperperfusion in the both frontal lobes, both parietal lobes and right temporal lobe corresponding to the abnormal findings detected by EEG. It also demonstrated an area of hyperperfusion in the right basal ganglia. It is suggested that 99mTc-HMPAO SPECT is useful for the diagnosis and the understanding of the clinical state of tic disorder.

Brain↗
PubMed1996

[Rhinovirus infection and expression of adhesion molecules in human tracheal epithelium].

Rhinovirus infection has attracted attention because it can lead to acute exacerbations of chronic inflammatory airway diseases such as bronchial asthma and chronic bronchitis. We established a culture system and inoculated human rhinovirus to human tracheal epithelial cells, and found that infection was augmented by up-regulation of intercellular adhesion molecule-1, which is the receptor for this virus. We also found that human airway epithelial cells infected with rhinovirus were susceptible to a chemical oxidant (H2O2) released by inflammatory cells, which would contribute to acute exacerbations of inflammatory airway diseases. Finally, we found that anti-ICAM-1 antibodies or dexamethasone can inhibit the infectivity to rhinovirus by suppressing ICAM-1, and diminish susceptibility to oxidants in the cultured human tracheal epithelium.

Anti-Inflammatory Agents↗
PubMed1995

Purification and characterization of an endothelial cell-viability maintaining factor from fetal bovine serum.

Serum is an essential requirement for the growth and long-term survival of human endothelial cells, even in the presence of such defined elements such as polypeptide growth factors and hormones. A polypeptide from fetal bovine serum was isolated and characterized on the basis of long-term survival of human endothelial cells in serum-free culture. The endothelial cell viability maintaining factor has been purified to homogeneity by a combination of polyethylene glycol precipitation, hydroxylapatite, gel permeation and reverse-phase high performance liquid chromatography. The final purified endothelial cell viability maintaining factor has a molecular weight of 65,000 (reduced) and has been identified as bovine apolipoprotein H by amino-terminal amino acid sequence analysis and Western blot analysis. Endothelial cell viability maintaining factor improved a long-term viability of human endothelial cells at maximal concentrations of 2.5-5 micrograms protein/ml in serum-free medium.

Amino Acid Sequence↗
PubMed1995

Secretory products of bovine oviductal epithelial cells support the viability and motility of bovine spermatozoa in culture in vitro.

The ability of secretions from the bovine oviduct to maintain the viability and motility of bovine spermatozoa was investigated by incubating frozen-thawed spermatozoa with oviductal flushings, uterine flushings, or the medium from cultures of oviductal epithelial cells and endothelial cells. The flushings obtained from both oviducts and uteri were effective for the maintenance of the viability and motility of spermatozoa, irrespective of the stage of the estrous cycle at which they had been collected. The flushings obtained from the ampullar region of oviducts at the follicular phase of the estrous cycle were most effective for the maintenance of viability and motile activity, for example, the forward motion of spermatozoa. Sperm viability and motility were also maintained by the medium from 6-hour culture of epithelial cells obtained from oviducts at the follicular phase of the estrous cycle. In contrast, the medium derived from bovine fetal artery endothelial cells had no significant effect on sperm viability and motility. These results suggest that the fluids of the female reproductive tract, in particular, the oviductal fluids at the follicular stage, provide a suitable environment for the maintenance of the viability and motility of bovine spermatozoa. It is also suggested that secretory product(s) of oviductal epithelial cells may play an important role in sustaining both the viability and motility of spermatozoa.

Animals↗
PubMed1995

Biochemical characterization of a bovine oviduct-specific sialo-glycoprotein that sustains sperm viability in vitro.

A bovine oviduct-specific glycoprotein (BOGP) that sustained the viability of bovine spermatozoa in vitro was purified from an extract of bovine oviducts. The amino-terminal amino acid sequence of BOGP was found to be a homologous with that of oviductin, a protein from hamster that was recently characterized by Mallete and Bleau (1993: Biochem. J. 295, 437-445). Purified BOGP was characterized as a sialo-glycoprotein containing N-linked and O-linked sialo-oligosaccharides side chains with galactose, mannose, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, fucose and sialic acids in its core protein (57 kDa). Intact BOGP has a wide range of isoelectric points (pIs) from 6.5 to 3.0 but a narrow range of molecular masses around 95 kDa. On isoelectric focusing of neuraminidase-treated BOGP (AS-BOGP), a narrow band with a pI of 9.3 was observed, and the ability of AS-BOGP to maintain sperm viability was negligible. We propose that BOGP is a mucin-type sialo-glycoprotein with a molecular mass of 72 kDa that contains one N-linked and approx. 15 O-linked sialo-oligosaccharide chains. These side chains appear to be important for the maintenance of sperm viability.

Amino Acid Sequence↗
PubMed1995

Bovine oviduct-specific glycoprotein: a potent factor for maintenance of viability and motility of bovine spermatozoa in vitro.

In the cow, a specific glycoprotein--bovine oviduct-specific glycoprotein (BOGP)--is secreted by the epithelial cells of the oviduct at the follicular stage of the estrous cycle. In this study, we examined the effects of purified BOGP on the viability and motility of bovine spermatozoa in culture in vitro. Frozen-thawed bovine spermatozoa were incubated in modified Tyrode's solution (TALP) that contained purified BOGP (TALP-BOGP). In TALP-BOGP, both the viability and motility of bovine spermatozoa were more effectively maintained than in the control medium without any added protein. The increases in both the viability and motility of spermatozoa were dose-dependent. Spermatozoa were also incubated in TALP medium supplemented with bovine serum albumin, egg albumin, lactalbumin, or gastric mucin, and their viability and motility in these media were compared with that in TALP-BOGP. Both the viability and motility of spermatozoa were more effectively maintained in TALP-BOGP throughout a 12-hr incubation than in other media tested. An immunolabeling study demonstrated that a monoclonal antibody specific for BOGP reacted with the posterior region of the head, the middle portion, and the tail of spermatozoa that had been incubated with TALP-BOGP, suggesting that BOGP becomes specifically associated with particular regions of the spermatozoon. These results suggest that BOGP is a potent factor for maintenance of the viability and motility of sperm. On the basis of the present results, we also propose that BOGP may play an important role in sperm functions during the reproductive process.

Animals↗
PubMed1995

Molecular cloning and characterization of a mouse oviduct-specific glycoprotein.

In the present study, we have isolated the cDNA for the mouse oviduct-specific glycoprotein (MOGP) by screening the mouse oviduct cDNA library with the bovine oviduct-specific glycoprotein (BOGP)-cDNA probe and by the 5' rapid amplification of the cDNA end (5'RACE). The total length of cDNA was determined to be 2525 base pairs (bp) by sequence analysis. The coding region contained 2163 bp translating to 721 amino acids. Based on comparisons with the N-terminal amino acid sequences of purified-BOGP and of hamster oviduct-specific glycoprotein (oviductin), it was inferred that the derived amino acid sequence contained a signal peptide region of 21 amino acids and a mature MOGP (core protein) region of 700 amino acids (76,515 daltons). It was also inferred that the mature MOGP contained three potential N-linked glycosylation sites and 24 possible O-linked glycosylation sites, and had the unique seven-residue repeat sequence (21 repeats) within the predicted sequence in the C-terminal side. The amino acid sequence of a portion of MOGP was highly homologous to that of BOGP (71% identity), baboon oviduct-specific glycoprotein (61% identity), and human oviduct-specific glycoprotein (77% identity). Significant homologies were also observed with two mammalian secretory proteins that were reported as a mammalian member of a chitinase protein family. Northern blot hybridization with a DIG-labeled probe indicated that a single message of 2.8 kb was present in total RNA prepared from oviductal tissue. In situ hybridization using MOGP-cDNA showed that a MOGP message was only detected in the oviductal epithelial cells. These results strongly suggest that a significant degree of homology exists among oviduct-specific glycoproteins of various mammalian species.

Amino Acid Sequence↗
PubMed1995

Molecular characterization of a hamster oviduct-specific glycoprotein.

There is growing evidence that the oviduct is not a passive conduit for gamete and embryo transport but serves a function for the gametes and/or embryos. The oviductal epithelium secretes one or more specific glycoproteins that associate with the egg after ovulation. Several published reports including our preliminary studies have suggested that the egg-associating glycoprotein(s) from the oviduct exists in several mammalian species including golden hamster. However, little or almost no biochemical characterization of the hamster oviduct-specific glycoprotein (HOGP) has been reported. To analyze the molecular structure of the HOGP in detail, we have attempted molecular cloning of cDNA corresponding to HOGP. A cDNA library constructed from the hamster oviduct in the phage vector lambda ZAPII was screened with digoxigenin-labeled, baboon oviduct-specific glycoprotein cDNA as the probe. A single positive clone was isolated, and the nucleotide sequence of the isolated cDNA was determined. Rapid amplification of cDNA end was carried out to obtain a proximal 5' cDNA end of the clone. The cDNA clone consisted of 2387 bp, and the coding region contained 2013 bp translating to 671 amino acids. The amino acid sequence deduced from the cDNA sequence confirmed the chemically determined NH2-terminal sequence of a HOGP and suggested that the derived amino acid sequence contained a signal peptide region (21 amino acids) and 650 amino acids (70,890 daltons) of the mature form of the HOGP region. The amino acid sequence of HOGP appeared to have eight potential N-glycosylation sites. Northern blot analysis revealed that a single message of approximately 2.5 kb was present in oviductal RNA but not in the RNA of several other hamster tissues. The HOGP showed high amino acid sequence homology with baboon, bovine, and human oviduct-specific glycoprotein. These results demonstrate that an oviduct-specific glycoprotein homologue gene exists in various mammalian species including rodent.

Amino Acid Sequence↗
PubMed1995

A comparative study of 123I-IMP SPET and CT in the investigation of chronic-stage head trauma patients.

The aims of this study were (1) to compare N-isopropyl-p-[I-123]-iodoamphetamine (123I-IMP) SPET with computed tomography (CT) in chronic-stage head trauma patients with neurological abnormalities and (2) to quantify regional cerebral blood flow (rCBF) in patients with chronic-stage head trauma. 123I-IMP SPET and CT were performed in 23 patients with chronic-stage head trauma and 12 normal controls. Both types of imaging were evaluated visually. In addition for the SPET images, the rCBF in 12 regions (bilateral frontal cortex, temporal cortex, parietal cortex, occipital cortex, perilolandic area, cerebellum: total 276 regions) was analysed quantitatively using a reference sampling method. In total, 39 focal lesions related to neurological abnormalities were detected. Although 22 (56.4%) lesions were observed using both CT and SPET, another 17 (43.6%) were detected by SPET only. The mean rCBF in the localized lesions of each lobe, which correspond to low-density areas (LDAs), were lower on CT than those of each lobe seen only on SPET. These rCBF values were lower than the mean rCBF values in the lobes of the controls. The mean rCBF values in each lobe with visually normal tracer uptakes were also significantly lower in the 23 patients than in the controls. 123I-IMP SPET is useful for demonstrating brain dysfunction in morphologically intact brain regions and for providing objective evidence to account for the clinical presentation of patients presenting with chronic traumatic brain injury.

Accidents, Traffic↗
PubMed1995

IL-5, IL-8 and GM-CSF immunostaining of sputum cells in bronchial asthma and chronic bronchitis.

BACKGROUND: Granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin (IL)-5 or IL-8 have been suggested to play an important role in the pathogenesis of eosinophilic airway inflammation in bronchial asthma or neutrophilic airway inflammation in chronic bronchitis, respectively, However, GM-CSF and IL-8 have biological activities to either eosinophils or neutrophils. OBJECTIVE: To investigate the contribution of these cytokines to airway inflammation, we compared the cellular differential and immunolocalization of GM-CSF, IL-5 and IL-8 in sputum cells from patients with bronchial asthma and chronic bronchitis. METHODS: Cytospins of sputum cells from 12 patients with bronchial asthma and 12 with chronic bronchitis were subjected to cellular differential counting and immuno-cytochemistry with anti-human GM-CSF, IL-5 and IL-8 antibody. RESULTS: The predominant cells in bronchial asthma were eosinophils and lymphocytes, while those in chronic bronchitis were neutrophils. All cytokines examined were detected in either bronchial asthma or chronic bronchitis, although the percentage of GM-CSF and Il-5 positive cells in bronchial asthma (53.4 +/- 6.0 [mean +/- SEM]% and 9.7 +/- 2.8%, respectively) was significantly higher than that in chronic bronchitis (11.4 +/- 2.5%; P < 0.001 and 1.7 +/- 0.3%; P < 0.007, respectively). In contrast, the percentage of IL-8 positive cells in chronic bronchitis (23.8 +/- 7.0%) was significantly higher than that in bronchial asthma (7.& +/- 1.9%; P < 0.04). The cells positive for IL-5 were lymphocytes in bronchial asthma and chronic bronchitis. The cells positive for GM-CSF in bronchial asthma were predominantly eosinophils, while those in chronic bronchitis were monocytes/macrophages and neutrophils. In contrast, neutrophils are mainly positive for IL-8 in chronic bronchitis, while monocytes/macrophages and bronchial epithelial cells are positive for IL-8 in bronchial asthma. CONCLUSION: The immunochemical comparison of GM-CSF and IL-8 localization in sputum cells between bronchial asthma/chronic bronchitis suggests the differential regulation and roles of these cytokines in eosinophilic vs neutrophilic airway inflammation, resulting in the development of different types of airway inflammation.

Adult↗