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Biomedical subjects

Y Matsuda

Publications and source records attributed to Y Matsuda.

At least 613 records · Page 34Linked to original sources
PubMed1993

Hygroscopic stability and dissolution properties of spray-dried solid dispersions of furosemide with Eudragit.

Spray-dried solid dispersions of furosemide-Eudragit RS100 and RL100 (ethyl methacrylate chlorotrimethylammoniumethyl methacrylate copolymer) were studied to determine their stability at 45 degrees C and 0, 44, and 75% relative humidity and their dissolution characteristics. The crystallization rates of the solid dispersions were measured by X-ray powder diffractometry and calculated on the basis of the Jander equation to estimate physicochemical stability in the presence of water vapor. The stability of the solid dispersion depended on the kind of acrylic resins and the drug content. The solid dispersion with a drug: Eudragit RL100 ratio of 1:3 was the most stable at 75% relative humidity. The dissolution profiles of the solid dispersions were measured in a pH 6.8 buffer at 37 degrees C. The equilibrium drug concentration of the solid dispersions were estimated from the dissolution profiles after 24 h. The equilibrium drug concentration decreased with an increasing Eudragit quaternary ammonium group: furosemide molar ratio. The equilibrium drug concentrations of the solid dispersions with > 0.3 mol of the quaternary ammonium group were approximately 0. Thus, the drug was completely adsorbed on Eudragit.

Acrylic Resins↗
PubMed1993

Effects of temperature and relative humidity on the solid-state chemical stability of ranitidine hydrochloride.

The chemical stability of ranitidine HCl in solution and in the solid state at various temperatures was investigated by high-performance liquid chromatography. Ranitidine HCl was unstable in lower pH buffer solutions, and the percent degradation after 72 h increased as the pH of the buffer solution was reduced. The percent degradation in the unbuffered solution increased dose dependently. The critical relative humidity (CRH) of the ranitidine HCl bulk powder was approximately 67% relative humidity (RH). The amount of water adsorbed onto the sample above the CRH was proportional to the RH level. The percent degradation of the powder below 50% RH was almost negligible because, at this level, it was a solid. The percent degradation at 60-70% RH was higher than that above 70% RH. Ranitidine HCl powder was unstable around the CRH.

Biological Availability↗
PubMed1993

Molecular cloning of the b subunit of mouse coagulation factor XIII and assignment of the gene to chromosome 1: close evolutionary relationship to complement factor H.

The b subunit of human coagulation factor XIII (FXIII-b) is composed of 10 short consensus repeats (SCRs) characteristic of the regulatory proteins of complement activation system. A full-length cDNA clone of mouse FXIII-b was isolated and the entire sequence was determined. The predicted amino acid sequence showed 77.5% homology with human FXIII-b, although mouse FXIII-b contained seven extra amino acid residues at the carboxyl terminal. The strong reactivity of the translation product of this clone with rabbit anti-human FXIII-b antiserum confirmed that it encodes a mouse counterpart of the human FXIII-b. By in situ hybridization and mapping studies using 66 interspecific backcross mice, the mouse FXIII-b gene (designated F13b) was shown to be located on distal chromosome 1 closely linked to Cfh, extending a conserved linkage group between human and mouse chromosome 1. In addition, a significant structural similarity between FXIII-b and complement factor H is described.

Amino Acid Sequence↗
PubMed1993

In situ analysis of centromere segregation in C57BL/6 x Mus spretus interspecific backcrosses.

The analysis of major satellite sequence differences between Mus spretus and laboratory mice provides a robust method for analyzing the centromere location for the genetic maps of each mouse chromosome. Fluorescence in situ hybridization (FISH) of a genomic probe, pMR196, for the laboratory mouse major satellite sequences was used to identify C57BL/6Ros (B6) pericentromeric heterochromatin in progeny of reciprocal backcross matings. These included 80 (B6 x M. spretus)F1 x M. spretus progeny (BSS) and 70 (B6 x M. spretus)F1 x B6 (BSB) progeny. FISH analysis of pericentromeric heterochromatin was conducted on the same metaphase spreads that were karyotypically analyzed for chromosome-specific banding patterns. Analysis of chromosomal segregation suggested that there was not primary deviation from random assortment during meiosis in the interspecific hybrid female, because nearly all of the 190 pair-wise comparisons did not deviate from expected and because there was no consistent pattern of deviation of the same chromosomes in the reciprocal backcross progeny from similar (C57BL/6 x M. spretus)F1 hybrid females. These results affirm the value of using the major satellite to genetically mark pericentromeric heterochromatin in the analysis of the segregation and assortment of centromeres in Mus interspecific crosses.

Animals↗
PubMed1993

Evaluation of hyperechoic liver tumors in MHTS.

Hepatocellular carcinoma (HCC) shares only a small proportion of hyperechoic liver tumors detected in MHTS and mimics hemangioma on ultrasonography (US). The precise diagnosis of HCC is hence difficult in MHTS, but presence or absence of underlying chronic liver disease and serum alfa-fetoprotein (AFP) titer might provide useful informations.

Biomarkers, Tumor↗
PubMed1993

HS-142-1, a novel antagonist for natriuretic peptides, has no effect on the third member of membrane bound guanylate cyclases (GC-C) in T84 cells.

HS-142-1, a novel non-peptide antagonist for natriuretic peptides, exerts antagonistic actions almost equally on two similar guanylate cyclase-linked natriuretic peptide receptors (GC-A and GC-B), but has little or no effect on the binding of natriuretic peptides to a membrane protein, the so-called "clearance receptor", which binds all natriuretic peptides. The third mammalian form of membrane bound guanylate cyclases (GC-C) was identified not as a natriuretic peptide receptor, but as a receptor for heat-stable enterotoxins (STa). In this study, we examined effects of HS-142-1 on GC-C (STaR) in T84 cells and showed that HS-142-1 exerts neither agonistic nor antagonistic activity for GC-C, indicating that HS-142-1 is not a common antagonist for a family of membrane bound guanylate cyclase receptors, but a specific antagonist for the guanylate cyclase-linked natriuretic peptide receptors.

Atrial Natriuretic Factor↗
PubMed1993

The application of titanium alloy wires for the reattachment of the greater trochanter in total hip arthroplasty.

We developed a new fixing method using titanium alloy wires in order to facilitate the attachment of the greater trochanter in total hip arthroplasty. This wire is composed of Ti-3Al-2.5V by weight. According to the fatigue test in vitro, the titanium alloy wire had better fatigue properties than Ortron 90 wire of the same diameter. In experiments in vivo, both titanium alloy wires and SUS-316L wires were used for the reattachment of the greater trochanter of dogs, and the titanium alloy wires showed better biocompatibility than the latter. Thus, titanium alloy wires seem applicable for the reattachment of the greater trochanter in human total hip arthroplasty.

Alloys↗
PubMed1993

HS-142-1 inhibits testosterone production and guanosine-3':5'-cyclic monophosphate accumulation stimulated by atrial natriuretic peptide in isolated mouse Leydig cells.

In this report, we describe the effects of a recently described atrial natriuretic peptide (ANP) antagonist, HS-142-1, on the action of ANP on Percoll-purified mouse Leydig cells. Incubation of the Leydig cells with 10(-8) M ANP for 3 h resulted in a 16-fold stimulation of testosterone production over basal. Addition of HS-142-1 in a concentration range of 0.1 to 5 micrograms/ml resulted in a dose-dependent inhibition of ANP-induced testosterone production, a nearly complete inhibition being achieved with 5 micrograms/ml antagonist. Testosterone production by unstimulated cells or in cells stimulated with hCG was not affected by the antagonist. HS-142-1 was also able to inhibit the ANP-stimulated cyclic guanosine monophosphate (GMP) formation in the cells, in a dose-dependent manner. However, cyclic AMP level in cells stimulated with either forskolin or hCG remained unaffected by HS-142-1 even when added at a concentration of 5 micrograms/ml. Results obtained from 125I-ANP binding experiments showed that HS-142-1 is able to competitively inhibit the binding of the radioligand to its receptors on the Leydig cells. Thus evidence obtained in this study permit us to conclude that HS-142-1 is a potent and specific antagonist of ANP, has no toxic effect on the cells and is able to inhibit competitively the binding of ANP to its guanylate cyclase coupled receptors. Availability of such antagonists are likely to facilitate research on the physiology of ANP.

1-Methyl-3-isobutylxanthine↗
PubMed1993

Physicochemical stability of phenobarbital polymorphs at various levels of humidity and temperature.

The physicochemical stability of six phenobarbital modifications [forms A, B, C (monohydrate), D (dioxane solvate), E (hemihydrate), and F] at various levels of humidity and temperature were measured using X-ray diffractometry and differential scanning calorimetry. Form D was identified as a new crystalline form (dioxane solvate). Polymorphic transformations of the modifications were investigated by the Kissinger method under nonisothermal conditions. Change of polymorphic content of phenobarbital modifications under various humidity levels at 45 degrees C was evaluated by X-ray powder diffraction. The polymorphic stability under isothermal conditions was estimated kinetically, based upon the Jander equation. Forms A, B, and F were stable at 0 and 75% RH and 45 degrees C for 3 months. On the contrary, forms C, D, and E transformed during storage. The transformation rates of form D were larger than that of forms C and E.

Calorimetry, Differential Scanning↗
PubMed1993

Cloning of human, mouse and fission yeast recombination genes homologous to RAD51 and recA.

Rad51, of Saccharomyces cerevisiae, is a homologue of recA of Escherichia coli and plays crucial roles in both mitotic and meiotic recombination and in repair of double-strand breaks of DNA. We have cloned genes from human, mouse and fission yeast that are homologous to rad51. The 339 amino acid proteins predicted for the two mammalian genes are almost identical and are highly homologous (83%) with the yeast proteins. The mouse gene is transcribed at a high level in thymus, spleen, testis and ovary and at a lower level in brain and other tissues. The rad51 homologues fail to complement the DNA repair defect of rad51 mutants of S. cerevisiae. The mouse gene is located in the F1 region of chromosome 2 and the human gene maps to chromosome 15.

Amino Acid Sequence↗
PubMed1993

Analysis of the characteristics of microheterogeneity of various serum glycoproteins in chronic alcoholics.

It has been reported that microheterogeneity of serum glycoproteins including transferrin is found in alcoholic liver disease. In the present study, microheterogeneity of serum glycoproteins in alcoholic liver disease patients was analysed using the Western blotting technique after isoelectric focusing. Microheterogeneity was found for serum alpha 1-antitrypsin, alpha 2-macroglobulin, caeruloplasmin, alpha 1-acid glycoprotein and hemopexin as well as transferrin. Microheterogeneity disappeared following treatment with sialidase in some but not all glycoproteins. In hemopexin, microheterogeneity was recognized only after treatment with sialidase. These results suggest that mechanisms of microheterogeneity of serum glycoproteins in alcoholic liver disease may vary. One mechanism may be the interference of glycosylation of glycoproteins in the Golgi apparatus, and another may be the decrease of asialo-protein receptors in hepatocytes.

Blotting, Western↗
PubMed1993

Effects of ethanol and acetaldehyde on the maturation of hepatic secretory glycoproteins.

The effects of ethanol and acetaldehyde on the maturation and secretion of hepatic glycoproteins in cultured rat hepatocytes were analysed using a pulse-chase labelling method and autoradiography following two-dimensional gel electrophoresis. A spot for transferrin was detected at mol. wt 77,000 and pI 5.2-5.4 on the autoradiogram in the control culture. The spot for transferrin shifted to the more basic isoforms by treatment for 3 hr with monensin or tunicamycin. The spot for transferrin also shifted to the more basic side by treatment with acetaldehyde for 3 hr or by additional treatment for 3 hr following pretreatment with ethanol for 6 hr. However, the shift of transferrin was not observed following treatment with ethanol for 3 hr. These results suggest that glycosylation of secretory glycoproteins in the Golgi apparatus is inhibited by acetaldehyde, but not by ethanol itself, and that this inhibition may play an important role in the development of alcoholic liver disease.

Acetaldehyde↗
PubMed1993

Ethanol and acetaldehyde metabolism in cultured rat hepatocytes.

In the present study, ethanol (Et-OH) and acetaldehyde (Ac-CHO) metabolism in primary cultured hepatocytes isolated from chronically alcohol-fed rats were analysed to elucidate the characteristics of the metabolism of Ac-CHO produced through the non-alcohol dehydrogenase (non-ADH) pathway. Dimethyl sulfoxide was added to the culture medium to prevent a decrease in P450 IIE1 activity. Ac-CHO formed in the culture medium was trapped by semicarbazide to prevent a reutilization of Ac-CHO by hepatocytes. The degradation rate of Ac-CHO in the liver was similar in alcohol and non-alcohol-treated rats. Therefore, the characteristic of the metabolism of Ac-CHO in the chronically alcohol-fed rats was not clarified in this study. The possibility that the Ac-CHO trapping by semicarbazide was only 70%, and that the remaining Ac-CHO was reutilized for oxidation in the hepatocytes, should be considered. Some method to trap Ac-CHO completely in the culture medium is needed to clarify the characteristics of Ac-CHO metabolism.

Acetaldehyde↗
PubMed1993

Role of the aldehyde dehydrogenase-1 isozyme in the metabolism of acetaldehyde.

At least four types of aldehyde dehydrogenase (ALDH) isozymes exist in human liver: acetaldehyde (Ac-CHO) is metabolized mainly by ALDH2. However, the role of ALDH1 in Ac-CHO metabolism is not well known, because ALDH1 deficiency is rare. In the present study, changes in blood levels of Ac-CHO were analyzed in a person with ALDH1 deficiency who is also heterozygous for the ALDH2 alleles, and subjects with normal ALDH1, in order to clarify the roles of ALDH1 in the metabolism of Ac-CHO. By isoelectric focusing analysis of ALDH in red blood cells (RBC), the ALDH1 band was not detectable in a male subject, indicating ALDH1 deficiency. In this subject, ALDH1 activity was nearly null, but the activities in his wife and two children were normal. Serial changes of blood Ac-CHO levels following a small amount of ethanol were analyzed. The peak levels of Ac-CHO were not different between the subject with ALDH1 deficiency and the person with normal ALDH1. However, the decrease from the peak values of Ac-CHO was clearly slower in the deficient subject than in ALDH1 normal subjects. Changes in Ac-CHO in blood were also analyzed in vitro. Ac-CHO metabolism by RBC from the ALDH1 deficient subjects was clearly slower than in those from controls. These results indicate that ALDH1 plays an important role in the metabolism of Ac-CHO in blood.

Acetaldehyde↗
PubMed1993

The relationship between the development of alcoholic liver and pancreatic diseases and the induction of gamma glutamyl transferase.

It is well known that the responses of serum gamma glutamyl transferase (GGT) to chronic alcohol drinking are different depending on the individual. In order to clarify the genetic backgrounds in the development of alcoholic liver and pancreatic diseases, the relationships between serum GGT response and alcoholic liver and pancreatic diseases in heavy drinkers were studied. The responses of GGT to alcohol drinking were classified into three groups: non-response, mild-response and hyperresponse. In alcoholic liver disease, non-responders were scarcely found and the response of GGT tended to increase in parallel with the progression of liver disease, when the hepatitis C virus (HCV) marker-positive patients were excluded. The differences in GGT levels between just after and at 4 weeks after abstinence in the HCV marker-negative patients were significantly higher than those in the HCV marker-positive patients. The rate of decrease in GGT activities during 4 weeks following abstinence was significantly higher in the HCV marker-negative patients than in the HCV marker-positive patients, indicating higher GGT induction in the HCV marker-positive patients. All patients with alcoholic pancreatitis, but without liver disease, were non-responders. All patients, except one, with severe pancreatitis were also non-responders. In alcoholic pancreatic disease, GGT induction correlated negatively with the development of pancreatitis. These results suggested that genetic polymorphism of GGT may link with the induction of GGT by alcohol drinking, and consequently link with the development of alcoholic liver and pancreatic diseases.

Adult↗
PubMed1993

Effects of ethanol and acetaldehyde on the contraction of cultured Ito cells.

The effects of ethanol (Et-OH) and acetaldehyde (Ac-CHO) on the contraction of cultured Ito cells were studied using a time-interval videotape recorder (VTR). Ito cells were isolated from Wistar rats and cultured for 4 days. The motion of the cells was recorded by VTR and the sequential changes of the surface area of the each cell were evaluated by an image analyzer. No contraction of Ito cells was observed after incubation with Et-OH (100 mM) or Ac-CHO (500 microM) alone. Ten nanomoles endothelin-1 (ET-1) caused Ito cells to contract gradually. Pre-incubation of ET-1 with Ac-CHO at 37 degrees C for 1 hr inhibited the contraction of Ito cells completely. This inhibition was not seen in pre-incubation of ET-1 with Et-OH. In addition, the Ito cells which were pre-cultured with Ac-CHO for 6 hr did not contract at all after incubation with ET-1. In the isoelectric focusing of ET-1, a band was clearly seen at pI 4.6 after the treatment with Et-OH as well as non-treated ET-1. Two extra bands of ET-1 appeared in the anodic side of the gel after treatment with Ac-CHO, indicating the conformational changes of ET-1. These results indicated that the contraction of Ito cells induced by ET-1 was inhibited completely by Ac-CHO. This inhibitory effect of Ac-CHO was thought to be caused by binding Ac-CHO to ET-1 itself or to ET-1 receptors.

Acetaldehyde↗