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Biomedical subjects

Y Matsuda

Publications and source records attributed to Y Matsuda.

At least 361 records · Page 20Linked to original sources
PubMed1997

Metallothionein expression and concentrations of copper and zinc are associated with tumor differentiation in hepatocellular carcinoma.

Metallothionein is the carrier protein of heavy metal ions, such as copper (Cu) and zinc (Zn). In this study, the relationships among immunohistochemical expression of metallothionein, concentrations of Cu and Zn, histological differentiation and proliferative activity of hepatocellular carcinoma were investigated in 51 cases. The concentrations of Cu and Zn in both tumor and non-tumor tissues were determined using electron probe microanalysis. Immunohistochemical expression of metallothionein in tumor tissues decreased with the degree of differentiation, whereas the number of hepatocytes positive for Ki-67 increased. Furthermore, the concentrations of Cu and Zn in tumor tissues decreased with the degree of histological differentiation in human hepatocellular carcinoma.

Biomarkers, Tumor↗
PubMed1997

Oestradiol release from self-setting apatitic bone cement responsive to plasma-calcium level in ovariectomized rats, and its physicochemical mechanism.

The effect of plasma calcium levels on the release of oestradiol from a self-setting apatite bone cement containing 0.5% oestradiol was investigated in ovariectomized rats. The profiles of in-vitro release from the cements in simulated body fluid containing 0, 5 or 10 mg calcium per 100 mL indicated that the rate of release of oestradiol decreased with increasing calcium concentration in the dissolution media. After subcutaneous implantation of oestradiol-loaded cement in healthy and vitamin D-deficient rats, oestradiol release in diseased rats with low plasma calcium levels was significantly higher than that in healthy rats. These results suggest that in-vitro release of oestradiol from apatite bone cement was dependent on the calcium concentration in the buffer and that the in-vivo release of oestradiol from apatite bone cement was dependent on plasma calcium levels.

Animals↗
PubMed1997

cDNA cloning, characterization, and chromosome mapping of UBE2E2 encoding a human ubiquitin-conjugating E2 enzyme.

A cDNA encoding a human ubiquitin-conjugating enzyme (E2) with N-terminal extension (UBE2E2/UbcH8) was isolated. Amino acid sequence within the UBC domain of UBE2E2 shares over 90% identity with human UbcH6, mouse UbcM2, and Drosophila UbcD2, whereas the N-terminal region shows little amino acid sequence similarity with known proteins. The UBE2E2 gene is transcribed in various tissues as a 1.9-kb transcript. The UBE2E2 protein formed a thioester bond with ubiquitin in an E1-dependent manner, indicating that the gene product is a functional E2 enzyme. The UBE2E2 gene was assigned to human chromosome 3p24.2 by fluorescence in situ hybridization.

Amino Acid Sequence↗
PubMed1997

Molecular cloning and chromosome mapping of rat phospholipase D genes, Pld1a, Pld1b and Pld2.

We have previously obtained three partial rat phospholipase D (PLD) cDNA fragments by a reverse transcriptase-polymerase chain reaction (RT-PCR) method using degenerate primers based on two conserved amino acid sequences in PLDs of human and yeast. The entire coding regions of these genes were isolated and sequenced. The longest clone, Pld1a encodes a 1075 amino acid (aa) protein that was highly similar (89% identity) to human PLD1a, especially in four conserved regions present in other PLDs. The nucleotide sequence of the second clone was identical to that of Pld1a except that the clone lacked 114 nucleotides corresponding to 38 aa in the middle. A shorter alternatively spliced form of human PLD1 (PLD1b) lacking the corresponding 38 aa was also identified. Therefore, the second clone (Pld1b) was considered to correspond to the rat counterpart of human PLD1b. The third clone, Pld2 encoding 933 aa was smaller than that of Pld1 and its aa identity to rat Pld1 was 56%. However, it contains four conserved regions and aa sequences of these regions are homologous to those of rat Pld1 and human PLD1. Its entire aa sequence was very similar (96% identity) to the recently cloned mouse PLD, Pld2. Chromosome locations of the Pld1a, Pld1b and Pld2 genes were determined in the rat and mouse by fluorescent in situ hybridization. As expected, both Pld1a and Pld1b clones were hybridized to the same chromosome regions. The Pld1 and Pld2 genes were localized to rat chromosome 2q23.3-->q24 proximal end and the proximal region of mouse Chromosome 3B, and rat chromosome 10q23.3-->q24 proximal end and mouse Chromosome 11B3, respectively. They were mapped in regions where conserved linkage homology has been identified between the two species.

Amino Acid Sequence↗
PubMed1997

Chromosomal mapping of the gene encoding serotonin N-acetyltransferase to rat chromosome 10q32.3 and mouse chromosome 11E2.

Pineal melatonin is produced during the night. Its nocturnal increase regulates circadian rhythms and the photoperiodic reproductive response. Serotonin is acetylated to N-acetylserotonin by serotonin N-acetyltransferase (SNAT) and then methylated to form melatonin by hydroxyindole-O-methyltransferase (HIOMT). The rhythmicity of melatonin synthesis is regulated by the rhythmic activity of SNAT. Most laboratory mice do not have melatonin because of a genetic defect in the activity of SNAT and/or HIOMT. In a previous study using a recombinant inbred strain, we have found that the locus controlling pineal SNAT activity (Nat4) is located on mouse Chromosome 11. Recently, SNAT has been cloned in the rat. In the present study, the gene encoding SNAT was localized, using a rat cDNA fragment, on rat and mouse chromosomes by direct R-banding fluorescence in situ hybridization (FISH). In addition, using molecular linkage analysis with interspecific backcross mice, a gene encoding SNAT was mapped on a mouse chromosome. The gene encoding SNAT was localized to rat chromosome 10q32.3 and mouse Chromosome 11E2 by FISH. The molecular linkage analysis demonstrated that the gene encoding SNAT maps 1.5 cM distal to D11Mit11. The data suggest that Nat4 encodes SNAT. These chromosomal locations are in a region of conserved linkage homology between the two species.

Animals↗
PubMed1997

Assignment of STK6 to human chromosome 20q13.2-->q13.3 and a pseudogene STK6P to 1q41-->q42.

Fluorescence in situ hybridization analysis of human STK6 encoding a mitotic centrosomal protein kinase, Aik, revealed two signals in chromosome bands 20q13.2-->q13.3 and 1q41-->q42. Somatic cell hybrid panel analyses showed the existence of an identical sequence to STK6 cDNA on chromosome 20, and a processed pseudogene on chromosome 1. These results suggest that STK6 is localized at 20q 13.2-->q13.3 and a pseudogene STK6P at 1q41-->q42.

Aurora Kinase A↗
PubMed1997

Effect of magnesium sulfate treatment on neonatal bone abnormalities.

OBJECTIVE: It has been reported that neonatal bone abnormalities occur as a result of long-term intravenous magnesium administration (MgSO4) to pregnant women. The purpose of this retrospective study was to evaluate the frequency of such abnormalities and the clinical background of both mothers and neonates. PATIENTS AND METHODS: We reviewed maternal (114 cases) and neonatal (139 cases) charts from all pregnant women who received intravenous MgSO4 administration for preterm labor and preeclampsia between June 1, 1992, and May 31, 1994. All chest X-ray films were obtained within 48 h after birth and reviewed by a doctor who was unaware of the clinical data. Radiolucent transverse metaphyseal bands of the proximal humerus were considered as abnormal. The subjects were divided into affected (group 1 and 1a) and unaffected (group 2 and 2a) groups. Neonates born to pregnant women given no MgSO4 at the same period, were considered as control. RESULTS: The total number of bone abnormalities in the offspring of mothers receiving MgSO4 amounted to 13 (11.4%). Group 1 consisted of 13 cases and group 2 of 101 cases. In the control group bone abnormalities were not observed (p < 0.05). Significant differences were found between groups 1 and 2 in the gestational ages at the start of MgSO4 administration and at delivery, and in the total duration of administration and doses of MgSO4. Also, cases of multiple pregnancy and pregnancy complicated with impaired glucose tolerance were more prevalent in group 1. According to the results obtained from 139 neonates, cases showing low Apgar and high magnesium score and those receiving respiratory support were more noticeable in group 1a (15 cases). CONCLUSIONS: The gestational ages and the total doses of MgSO4 in pregnant women were the main factors related to the onset of neonatal bone abnormalities, but other factors also have a possible bearing on the condition. In addition, the cases with onset of bone abnormality seemed to be associated with symptoms attributable to hypermagnesemia of neonates.

Bone Development↗
PubMed1997

High concentration of glucose increases mitogenic responsiveness to heparin-binding epidermal growth factor-like growth factor in rat vascular smooth muscle cells.

The effect of a high extracellular glucose concentration on the mitogenic response of rat vascular smooth muscle cells (SMCs) to heparin-binding epidermal growth factor-like growth factor (HB-EGF) was investigated. The mitogenic effect of HB-EGF was significantly greater in SMCs cultured in high glucose (25 mmol/L) than in cells cultured in low glucose (5.5 mmol/L) or at high osmolarity (5.5 mmol/L glucose plus 19.5 mmol/L mannitol). The mitogenic effect of epidermal growth factor (EGF), which shares the EGF receptor with HB-EGF, was not affected by glucose concentration. The mitogenic effect of HB-EGF was greater when incubated with heparan sulfate (HS) isolated from SMCs cultured in high glucose than with HS from cells cultured in low glucose. HS synthesized by cells in high glucose was of smaller molecular size and less sulfated than HS synthesized by cells in low glucose. The abundance of mRNA encoding HS-N-deacetylase/N-sulfotransferase (HS-NdAc/NST), a regulatory enzyme in the biosynthesis of HS, was decreased by high glucose in a protein kinase C-independent manner. These observations suggest that the enhanced mitogenic response to HB-EGF in SMCs cultured in high glucose may be attributable to changes in cell-associated HS. Downregulation of HS-NdAc/NST gene expression by high glucose may be related to the altered HS biosynthesis.

Animals↗
PubMed1997

[Kinase inhibitors of microbial origins].

Microorganisms are beneficial as a source of natural products in the following sense, diversity of species, versatility and variety of substrates, and unique productivity. On top of them, advantage for industrial utilization of microorganisms is that mass production is feasible by culturing them in a fermentation tank. We have been looking for new substances which interact with a molecule involved in biological responses in animal cells. Among them, we summarize our kinase inhibitors isolated from microbial culture in this paper.

Androstadienes↗
PubMed1997

Osteoblastoma of the nasal cavity invading the anterior skull base in a young child. Case report.

The benign osteoblastoma is rarely seen as a tumor of the facial bone in infancy or early childhood. Only five cases with nasal involvement have been reported in the literature. The authors present a case of osteoblastoma of the nasal cavity, the nasal bone, the ethmoid sinus, and the anterior cranial base. This 3-year-old girl presented with a tumor surrounding the left medial canthus. Imaging studies, including x-ray films, computerized tomography scans, magnetic resonance images, a (99m)Tc-scintigram, and angiograms, confirmed the location of the tumor. A biopsy specimen of tumor was obtained intranasally and the pathological diagnosis was an osteoblastic tumor suggestive of osteoblastoma. Although the tumor margin was well defined on the radiological images, it was difficult to determine the exact margin during the operation. Therefore, it is important to show how to excise the tumor completely under direct view. With the use of a "dismasking flap," it was possible to resect the benign osteoblastoma completely from the nasal cavity, even though it extended into the orbit, the maxilla, and the anterior cranial base.

Angiography↗
PubMed1997

MS-681a, b, c and d, new inhibitors of myosin light chain kinase from Myrothecium sp. KY6568. I. Characterization of producing strain and production, isolation and biological activities.

Novel compounds MS-681a, b, c and d were isolated from the culture broth of a fungal strain KY6568. The strain was identified as Myrothecium sp. from its morphological characteristics. MS-681a, b, c and d inhibited the activity of purified smooth muscle myosin light chain kinase with IC50 values of 0.11, 0.29, 0.095 and 0.26 microM, respectively. Cyclic AMP-dependent protein kinase, cyclic GMP-dependent protein kinase and protein kinase C were not inhibited at 100 microM by MS-681 compounds.

Aminoisobutyric Acids↗
PubMed1997

[Alteration of myocardial contractility during progressive hypoxemia in pigs].

Myocardial contractility independent on the loads of the heart was examined during progressive hypoxemia in nine pigs. left ventricular pressure-volume relation (LVPVR) was analyzed to obtain end-systolic elastance (Ees) and ventriculoarterial coupling (Ea/Ees), concomitantly with the measurements of cardiac output (CO), systemic oxygen delivery (DO2) and other indicators of systemic oxygen metabolism. Hypoxemia was induced by reducing inspired oxygen fraction (FIO2), and the measurement was performed at an FIO2 levels of 0.21, 0.18, 0.15, 0.13, 0.11 and 0.10. During progressive hypoxemia, a maximal increase in CO was observed at FIO2 of 0.11 (P < 0.05, vs FIO2 0.21), while, Ees reached the maximum at FIO2 of 0.13 (P < 0.05, vs FIO2 0.21), then it decreased below FIO2 of 0.11. Ea/Ees showed the best ventriculoarterial coupling at FIO2 of 0.13, and the coupling worsened below FIO2 of 0.11. It is concluded that load-independent myocardial contractility started to decline even when CO was still increasing to compensate the reduction of DO2 during progressive hypoxemia.

Animals↗
PubMed1997

The in vitro and in vivo indomethacin release from self-setting bioactive glass bone cement.

The in vivo and in vitro drug release profiles from a self-setting bioactive CaO-SiO2-P2O5 glass bone cement containing indomethacin as a model drug were investigated. The cement containing 2% and 5% indomethacin (IMC) powder hardened within 5 min after mixing with ammonium phosphate buffer. After setting, in vitro drug release from drug-loaded cement pellets in a simulated body fluid (SBF) at pH 7.25 and 37 degrees C continued for two weeks. The hardened cement gradually formed low-crystallinity hydroxyapatite during the drug release test in SBF. An IMC-loaded cement device (2% and 5% drug) was implanted in the subcutaneous tissue on the back of rats. The in vivo IMC release from the cement increased and attained maximum levels (Cmax of 2% and 5% drug-loaded cements was 0.27 and 3.37 micrograms/ml, respectively) at Tmax, 3 and 0.5 d, respectively, upon subcutaneous (s.c.) administration in rats. This suggested that the s.c. administration of the cement provided IMC release for a much longer period than s.c. administration of the solution, and the plasma IMC concentration was dependent on the drug concentration in the cement. The plasma IMC concentration and the area under the curve from 2% and 5% IMC-loaded cements in rats were dependent on the concentration of IMC in the cements. The in vivo IMC concentration in plasma obtained by the deconvolution method was much lower than that delivered in SBF in vitro. Scanning electron microscopy and photomicrographs of cross sections showed that the bioactive bone cement had excellent biocompatibility with the surrounding soft tissues.

Animals↗
PubMed1996

Chromosomal localization of the mouse and rat DNA double-strand break repair genes Ku p70 and Ku p80/XRCC5 and their mRNA expression in various mouse tissues.

The Ku p70 and Ku p80/XRCC5 genes are involved in DNA double-strand break repair and V(D)J recombination, and their gene products are the components of the DNA-dependent protein kinase. We have determined the chromosomal locations of the mouse Ku p70 and Ku p80/XRCC5 genes by both in situ hybridization and molecular linkage analysis: the Ku p70 gene was localized to mouse chromosome 15 and rat chromosome 7, and the Ku p80/XRCC5 gene was localized to mouse chromosome 1 and rat chromosome 9. Both genes were mapped to a region of conserved linkage homology among three species, i.e., the mouse, rat, and human. Molecular linkage analysis using interspecific backcross mice revealed that the murine Ku p70 locus was localized 0.7 cM terminal to D15Mit1 and that the murine Ku p80/XRCC5 locus was 0.7 cM proximal to D1Mit46. To determine the size and tissue transcription specificity of the mouse Ku p70 and Ku p80/XRCC5 mRNA, Northern blot analysis was carried out with six mouse tissues. Each tissue expressed one species of the Ku p70 gene transcript with 2.4 kb and one species of the Ku p80/XRCC5 gene transcript with 2.6 kb. In the latter case, however, the brain showed two sizes of transcript, 2.6 and 2.9 kb.

Animals↗
PubMed1996

Limited proteolysis by chymotrypsin of midkine and inhibition by heparin binding.

When digested with a low concentration of chymotrypsin, midkine (MK) underwent limited proteolysis and produced two fragments with Mr of 11,000 and 6,000 Da. The cleavage site was identified as on the carboxyl side of Phe55. This limited proteolysis was specifically inhibited by heparin, but not by other glycosaminoglycans. Using various heparin-derived oligosaccharides with different chain lengths or chemically desulfated heparin derivatives, it was shown that a minimum of 6 monosaccharide units was necessary for the inhibition, and that sulfonyl groups of the heparin disaccharide unit were required for inhibition. The present study showed that MK consists of two domains, N- and C-domains, and that Phe55 localized to the hinge region is exposed on the surface of the molecule. It was also suggested that the N-domain may function as a stabilizing domain against proteolytic degradation of the C-domain in the intact molecule.

Amino Acid Sequence↗