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Biomedical subjects

Y Hoshikawa

Publications and source records attributed to Y Hoshikawa.

72 records · Page 4Linked to original sources
PubMed1992

[Primary hemangiopericytoma of the chest wall--a case report].

An extremely rare case of a primary hemangiopericytoma of the chest wall was reported. A 40-year-old female without any complaints was detected to have an abnormal shadow in the right chest wall on a chest X-ray film. The tumor was 2.6 x 2.2 x 2.0 cm in size and was resected together with the 8th rib which adhered to the tumor. Postoperative pathohistological examination led to the diagnosis of hemangiopericytoma. Postoperative course was uneventful, and the patient is now doing well and has had no recurrence for 11 months since the operation. A brief review was made on 9 cases collected from the literature.

Adult↗
PubMed1991

Species difference of site-selective glucuronidation of morphine.

Species difference in glucuronidation of morphine was studied using mice, rats, guinea pigs and rabbits in vivo and in vitro. Morphine-3-glucuronide (M-3-G) and morphine-6-glucuronide (M-6-G) were determined by high-performance liquid chromatography. M-3-G was the major urinary metabolite of morphine in all these animal species. However, a remarkable species difference was observed in the urinary excretion of the M-6-G. Excretion ratios of the M-3-G to M-6-G were approximately 4:1 and 50:1 in guinea pigs and rabbits, respectively. The urinary excretion of M-6-G in mice and rats was too small to be determined. On the other hand, the ratios of uridine diphosphate-glucuronyltransferase (UDPGT) activities toward 3- and 6-hydroxyl groups of morphine in liver microsomes of mice, rats, guinea pigs and rabbits were approximately 300:1, 90:1, 4:1 and 40:1, respectively. Ratios of two morphine UDPGT activities in the liver microsomes of guinea pigs and rabbits, thus, reflected those of urinary excretion of morphine glucuronides.

Animals↗
PubMed1991

Re-investigation of ontogenesis of epidermal growth factor receptor mRNA in the liver of rats: quantitative evaluation of northern blot analysis.

Changes in the expression rate of epidermal growth factor receptor (EGFR) mRNA with age in the liver of rats were examined to assess the contribution of EGF to the proliferation of hepatocytes in younger animals. Northern blot analyses with a 32P-labeled probe derived from the extracellular domain of EGFR cDNA were evaluated quantitatively by normalizing the densitometric scanning data with the relative amounts of poly(A)+ RNA in the samples. The expression of EGFR mRNA was low during the early period and increased towards the adult level after 21 days of birth. In contrast, the rate of beta-actin mRNA expression was significantly higher immediately after birth and showed a tendency to decrease with time.

Actins↗
PubMed1991

Isolation and characterization of cDNA clones for castration-induced mRNAs in the rat ventral prostate.

To identify gene products involved in castration-induced involution of the rat ventral prostate, we constructed a subtraction cDNA library of the ventral prostate from rats castrated for 48 h. The library was screened with subtracted cDNA probes enriched for sequences with a low copy number expressed in intact or castrated rats. As a result of differential screening, 48 cDNA clones representing 10 different induced mRNAs were isolated. The time course of these mRNA inductions after castration was examined. Within the first 24 h after castration, the level of mRNAs for these cDNA clones was significantly increased and it reached its peak by 48-72 h after castration. Although mRNAs for these cDNA clones were expressed in various tissues from intact rats, an increase in mRNA as a response to castration was observed only in the ventral prostate. Partial sequence analyses of the 10 cDNA clones indicate that three cDNA clones represent rat glutathione S-transferase Yb-1, Yb-2 and Yb-3 subunit mRNA sequences, but for others respective homologues could not be found in a search of the GenBank database (release 67).

Animals↗
PubMed1990

Species difference in codeine uridine diphosphate-glucuronyltransferase activity of liver microsomes.

Species difference in codeine uridine diphosphate-glucuronyltransferase (UDPGT) activity was studied in liver microsomes of mice, rats, guinea pigs and rabbits. Codeine UDPGT activity was the highest in guinea pigs, followed by that in rabbits, and the lowest in mice and rats among these four animal species. The specific activities of codeine UDPGT in liver microsomes were not correlated well with those toward morphine, 4-nitrophenol, and 4-hydroxybiphenyl in liver microsomes of each of the species. Inducibility of liver microsomal codeine UDPGT activity in rats was examined by pretreatment with phenobarbital and 3-methylcholanthrene and compared with those of other UDPGT activities. The activity was inducible by phenobarbital pretreatment as the activity toward morphine and 4-hydroxybiphenyl. The inducibility of codeine UDPGT activity by phenobarbital pretreatment was not as high as that of morphine UDPGT activity.

Animals↗
PubMed1990

Epidermal growth factor receptor mRNA in livers from newborn, adult and partially hepatectomized rats.

Epidermal growth factor (EGF) receptor mRNA expression in livers of newborn, adult control and partially hepatectomized rats 1 and 3 days post-operation was examined by Northern blot analysis. A human EGF receptor cDNA (P 64-1, Ullrich et al., 1984) was hybridized to RNA species of 10, 6 and 3 kb. These mRNAs were profoundly decreased in livers from newborn rats and relatively decreased in regenerating rat livers. beta-Actin mRNA in these tissues showed a tendency to increase over that of the adult controls.

Animals↗
PubMed1990

Structural specificity for biological activity of trichostatin A, a specific inhibitor of mammalian cell cycle with potent differentiation-inducing activity in Friend leukemia cells.

Biological activities of four chemically synthesized trichostatin-related compounds, (R)-trichostatin A, (S)-trichostatin A, (R)-trichostatic acid, and (S)-trichostatic acid, were investigated. Assays of differentiation-inducing activity in Friend leukemia cells and G2-arresting activity in the cell cycle of normal rat fibroblast cells were used as monitoring systems for comparing the bioactivities of these compounds. The results clearly showed that both of the enantiomers of trichostatic acid had no activity in both the assay systems. In the case of (S)-trichostatin A, the antipode of naturally occurring trichostatin A, 50% effective concentrations were determined to be 50-70-fold higher than those of (R)-trichostatin A. The relationship between this ratio and the value of enantiomeric excess strongly suggests that (S)-trichostatin A is also biologically inactive. These results indicate that the absolute configuration and the presence of the hydroxamate group of trichostatin A are essential for its biological activity.

Animals↗
PubMed1990

[A case of advanced thoracic esophageal cancer with marked response to bleomycin absorbed on activated carbon particles (BLM-CH44), methotrexate, and cisplatin].

A 67-year-old women, who suffered from advanced esophageal cancer with left main bronchus and azygous vein involvement, was treated by combined administration of bleomycin absorbed on activated carbon particles (BLM-CH44, 10 mg/body), methotrexate (30 mg/body i.m.), and cisplatin (75 mg/body i.v.). BLM-CH44 was injected around tumor and total dose of BLM was 120 mg, that of MTX was 180 mg, and that of CDDP was 225 mg. After therapy, the sign of extra-esophageal spread disappeared and a radical operation was performed. Microscopically, the lesion of the esophagus was almost disappeared, and CH44 staining lymph node involvement was completely disappeared.

Aged↗
PubMed1990

Roentgenographic and clinical findings of patellofemoral osteoarthrosis. With special reference to its relationship to femorotibial osteoarthrosis and etiologic factors.

In order to determine definitive clinical and roentgenographic findings of patellofemoral osteoarthrosis (PF-OA) and the etiologic factors of this disease as well as its relationship to femorotibial osteoarthrosis (FT-OA), 108 knees having moderate to severe PF-OA with or without FT-OA were investigated. Pain and disabilities of activities of daily living (ADL) due to PF-OA most likely appeared during movements requiring deep flexion of the knee. Roentgenographic findings revealed a great majority of the disease occurred on the lateral side of the PF joint, both in cases of PF-OA alone and in PF-OA combined with FT-OA. There was no relationship between the degree of PF-OA advancement determined by roentgenographic findings and that of ADL disabilities. PF-OA and FT-OA seemed to be caused by different etiologic factors, because the degrees of involvement of the PF and FT joints were not correlated with each other in the cases of PF-OA combined with FT-OA. Since a clear history of dislocation or subluxation of the patella was noted in 18% of PF-OA (this figure increased to 28% if limited to the cases affected with PF-OA alone), and since roentgenographic findings also agreed with this evidence, dislocation or subluxation of the patella seemed to be one of the causes of PF-OA.

Activities of Daily Living↗
PubMed1988

Cloning of glucocorticoid-responsive mRNA in the rat thymus.

To elucidate the molecular mechanism of rat thymus involution induced by administration of glucocorticoid, we screened a cDNA library for polysomal poly(A)+RNA from adrenalectomized rat thymi by a differential colony hybridization method. Labeled cDNAs for mRNAs isolated from thymi of adrenalectomized rats and rats receiving dexamethasone (Dex) treatment were used as probes. Eight cDNA clones for mRNAs which had a diminished response to administration of Dex were isolated. The relative concentration of cloned mRNAs in the thymic polysomal RNA was significantly decreased 3 h after hormone administration, while changes in the nuclear RNA were not significant after Dex administration. One of the selected cDNA clones designated pRTGR-8 corresponded to mRNA of about 3,000 nucleotides, and a nuclear run-off transcription assay indicated that the rate of transcription of pRTGR-8 RNA was repressed by Dex administration. The cloned cDNAs obtained in this experiment may provide useful probes for studying the negative regulation mechanism of gene expression by glucocorticoids.

Animals↗
PubMed1988

Binding sites for epidermal growth factor in nuclear fraction from rat liver.

Binding sites for mouse epidermal growth factor (EGF) were observed in purified nuclear fraction from rat liver. The binding data yielded a curvilinear Scatchard plot which was decomposed into two binding components with different binding affinities. The binding component with higher affinity (Kd approximately 10(-10) M) represented approximately 15% of the total binding, while the high affinity binding sites were less than 5% of the total in the microsomes. The ligand-dependent autophosphorylation, one of the characteristic features of EGF receptor in the plasma membrane, was not observed at the site of the receptor (170 KDa) in the nuclear fraction. The binding characteristics for EGF fluctuated during the course of liver regeneration after partial hepatectomy; the binding capacity in the nuclear fraction increased in contrast to the decrease in the microsomes. However, the binding sites in the nuclear fraction obtained in the early period after partial hepatectomy consisted only of low affinity ones.

Animals↗
PubMed1986

Receptor binding in the rat liver nuclear matrix.

3H-Dexamethasone (Dex)-receptor complexes prepared from the rat liver cytosol efficiently bound to the nuclear matrix from the same tissue. The binding was increased with the concentration of the 3H-Dex-receptor complex added and reached a maximum plateau. However, when the partially purified 3H-Dex-receptor complex was used, saturation of the binding sites in the nuclear matrix was not observed in the range of concentration of 3H-Dex-receptor complex used. Therefore, it was considered that the apparent saturability observed in the binding of the unpurified receptor complexes is caused by the translocation inhibitor(s) in the cytosol. When the binding capacity was expressed on the basis of unit weight of DNA, the nuclear matrix exhibited 20 times more of that of the unfractionated nuclei. However, no line of evidence of enrichment of the binding sites in the DNA isolated from the nuclear matrix was observed. These observations show that the role of the nuclear matrix in the action of glucocorticoid is quite uncertain.

Animals↗
PubMed1984

Sequence analysis of the transcribed and 5' non-transcribed regions of the ribosomal RNA gene in Dictyostelium discoideum.

The nucleotide sequence of Dictyostelium discoideum rDNA extending over almost the entire transcribed region and a part of the 5' non-transcribed spacer region has been determined. Computer analysis revealed that there were several conserved sequences in the 17S, 5.8S and 26S coding regions when compared with the sequences at analogous positions in some eukaryotic rRNA genes. The data also showed that the D. discoideum rDNA contains several extra sequences, which have not been found in other eukaryotes' rDNAs , near the 3' terminus of the 17S coding region and the 5' terminus of the 26S coding region.

Animals↗
PubMed1983

Nucleotide sequence of the transcriptional initiation region of Dictyostelium discoideum rRNA gene and comparison of the initiation regions of three lower eukaryotes' genes.

The 5' end of the rRNA precursor of D. discoideum was mapped on a cloned rDNA by S1 nuclease protection mapping, and the sequence of about 1240 nucleotides surrounding the transcriptional initiation site of the rRNA gene has been determined. Repeated sequences consisting of 16 nucleotides appeared in the region upstream from the initiation point. Comparison of the nucleotide sequences around the initiation site of rRNA genes in three lower eukaryotes, D. discoideum, Saccharomyces cerevisiae and Tetrahymena pyriformis, indicated that there was little similarity in the nontranscribed spacer regions, but in the transcribed spacer regions near the initiation point, very similar sequences consisting of 9 nucleotides were found.

Animals↗
PubMedDate not supplied

The prognosis of meniscectomy in athletes. The simple meniscus lesions without ligamentous instabilities.

This study analyzes patient participation in athletic activities after meniscectomy. Seventy simple meniscus lesions in 68 patients without ligamentous insufficiency were studied by means of a detailed questionnaire and clinical and radiological examinations. Follow-up ranged from 1 to 18.4 years, averaging 4.5 years. These cases are classified into two groups, depending on the intensity of athletic activities. Group 1 consisted of international class athletes and Group 2 consisted of both competitive and recreational athletes. None of those studied have given up sports following meniscectomy. Results were worse in Group 1 than in Group 2 in both clinical and subjective evaluation. In Group 1 volleyball players presented results worse than those of football (American style) players and wrestlers. In Group 2 there was no significant difference in results among athletes of various sports. We conclude that the results after meniscectomy are influenced by the quality and frequency of postoperative athletic activities.

Adolescent↗