Search PubMed⌕ Search

Biomedical subjects

T Baba

Publications and source records attributed to T Baba.

At least 73 records · Page 4Linked to original sources
PubMed2001

Genomic structure of mouse copper chaperone, COX17.

Coxl7p was first cloned as a cytoplasmic copper chaperone from yeast mutant and recent works suggested the existence of mammalian homologues. Previous report has shown that a gel filtration fraction of heart extract containing porcine Coxl7p peptide promoted the survival of NIH3T3 fibroblast cells. In the present study, we first cloned DNA fragments of the mouse COX17 gene. The mouse COX17 spans approximately 6kb and consists of three exons. It was mapped to the center of chromosome 16, using a radiation hybrid-mapping panel. The major transcription start site is 80 bp upstream of the ATG initiation codon as determined by rapid amplification of cDNA ends (5'-RACE) analysis. Two potential polyadenylation sites are 3233 and 3293 bp downstream of the termination codon, respectively. Transient transfection of reporter plasmids containing portions of the mouse COX17 5'-flanking region into AtT-20 and NIH3T3 cells allowed the localization of the essential promoter to a 0.8 kb region upstream of the transcription starting site. Furthermore, the transfected luciferase activity was much higher in AtT-20 than NIH3T3. According to sequence analysis of the approximately 0.8kb 5'-flanking region, GC rich segments including consensus sequences for binding of the transcription factor Sp1, but no TATA/CAAT boxes, exist in the region of the transcription start site. Besides the GC box, binding sites for NRF-1 and 2 known as specific transcription factors for COX subunits are also localized around the transcription starting site.

Animals↗
PubMed2001

Species differences in beta-oxidative metabolism of a thromboxane A2-receptor antagonist [(+)-S-145] in rat, dog and monkey.

1. The formation of beta-oxidized metabolites from (+)-S-145 [(+)-(Z)-7-[(1R, 2S, 3S, 4S)-3-(benzenesulphonamide)bicyclo-[2.2.]-hept-2-yl]-5-heptenoic acid] by liver homogenates were compared between rat, dog and monkey. Species differences were found in hepatic beta-oxidation capacities. The results agree with the qualitative and quantitative differences in beta-oxidized metabolite proportions among these species observed in vivo. 2. The activities of microsomal (+)-S-145-CoA synthesis, the initial step of the beta-oxidation, were determined. Species differences in their intrinsic clearances primarily agreed with those of the beta-oxidized metabolite formation. 3. (+)-S-145-CoA oxidation activities towards (+)-S-145-CoA by liver homogenates were much higher than the beta-oxidized metabolite formation in all species, indicating that formed (+)-S-145-CoA was immediately beta-oxidized in peroxisomes. The species differences were inconsistent with those of beta-oxidized metabolite formation in vitro. 4. Therefore, quantitative differences of hepatic (+)-S-145 beta-oxidation capacity in rat, dog and monkey were considered to be mainly due to the species difference in (+)-S-145-CoA formation.

Animals↗
PubMed2001

Ultrastructural study of mouse renal glomeruli under various hemodynamic conditions by an "in vivo cryotechnique".

Three-dimensional ultrastructure of mouse renal glomeruli under various hemodynamic conditions was studied by scanning electron microscopy with an "in vivo cryotechnique" followed by freeze-substitution. These results were also compared with those of conventionally fixed glomeruli at different perfusion pressures. Some kidneys of anesthetized mice were directly frozen in vivo under normal blood flow condition. Others were frozen in the same way after ligation of the lower abdominal aorta or their heart arrest. The frozen specimens were routinely freeze-substituted, freeze-dried and ion-sputtered for SEM. For another conventional fixation method, some kidneys were perfused with glutaraldehyde at pressures of 150 cm or 250 cm water, and other renal cortical tissues were routinely immersion-fixed with glutaraldehyde. In freeze-substituted specimens with the in vivo cryotechnique, interdigitating foot processes of podocytes exhibited smooth surface contours with less shrinkage and their surfaces were arranged more tightly than those seen by the conventional fixation method. In the anesthetized mice, filtration slits between the foot processes were found to be narrow after the heart arrest, but they were wide under the normal blood flow condition. After the aorta ligation, the filtration slits became wider and the foot processes were more elongated. The ultrastructure of capillary loops in functioning renal glomeruli were revealed to be dynamically changing in the living state, depending on various hemodynamic conditions.

Animals↗
PubMed2001

Association of the DD genotype and development of Japanese type 2 diabetic nephropathy.

We determined the insertion/deletion (I/D) polymorphism of the angiotensin-coverting enzyme (ACE) gene in a multicenter trial of ethnically homogeneous Japanese type 2 diabetes mellitus (DM) patients. All patients (n = 748) were divided into 5 groups as follows: group I (normoalbuminuric patients), group II (microalbuminuric patients), group III (overt albuminuric patients with serum creatinine (s-Cr) levels of less than 1.2 mg/dl), group IV (overt albuminuric patients with s-Cr levels of more than 1.3 mg/dl but excluding hemodialysis patients), and group V (hemodialysis patients). We selected patients with a diabetic duration of more than 15 years in the mild stage (groups I and II), but placed no limits on those in the advanced and end-stages (groups III, IV and V). The frequency of the DD genotype was slightly higher in the advanced and end stages. The frequency of the DD genotype in the mild stage differed from that in the end stage (II/ID/DD 47.8%/41.0%/11.2% vs. 37.0 %/43.3%/19.7% p = 0.07, II + ID/DD 88.8%/11.2% vs. 80.3%/19.7%, p < 0.05). D allele frequency in the mild stage also differed from that in the end stage (I/D 68.3%/31.7% vs. 58.7%/41.3%, p < 0.02). The presence of the DD genotype increased the risk of end-stage renal disease (ESRD) more than that of the other genotypes (odds ratio ID/II = 1.37, 95% CI 0.82-2.27; DD/II = 2.27, 95% CI 1.12-4.61). It appears that the DD genotype is associated with progression of Japanese type 2 diabetic nephropathy.

Aged↗
PubMed2001

[Wood creosote: a historical study and its preparation in combination with herbal drugs].

Two kinds of creosote have been found based on historical evidence of the medicinal uses and origins. One is wood creosote, and distillate of wood-tar containing guaiacol and creosol. The other type of creosote is coal-tar creosote, obtained from coal-tar, containing naphthalene and anthracene as the major constituents. Wood creosote was prepared for the first time in Germany in 1830 and was used for medicinal purposes. It had been listed officially in the German, American, and Japanese Pharmacopoeia as an antibacterial agent for the treatment of pulmonary tuberculosis, diarrhea, and external injury. In recent days, it has been deleted from the Pharmacopoeia in Western countries and not officially used for medicinal purposes. However, wood creosote is still been listed in the Japanese Pharmacopoeia and is used for the treatment of diarrhea. Since the interest of common people in herbal medicines and self-medication has been increasing, the use of wood creosote has also been modified in combination with some herbal drugs, "Seiro-gan" especially is quite popular in Japan as a self-medication for digestive trouble, including food poisoning or diarrhea.

Creosote↗
PubMed2000

Identification of a novel isoform of poly(A) polymerase, TPAP, specifically present in the cytoplasm of spermatogenic cells.

We have identified cDNA clones encoding a testis-specific poly(A) polymerase, termed TPAP, a candidate molecule responsible for cytoplasmic polyadenylation of preexisting mRNAs in male haploid germ cells. The TPAP gene was most abundantly expressed coincident with the additional elongation of mRNA poly(A) tails in round spermatids. The amino acid sequence of TPAP contained 642 residues, and shared a high degree of identity (86%) with that of a nuclear poly(A) polymerase, PAP II. Despite the sequence conservation of functional elements, including three catalytic Asp residues, an ATP-binding site, and an RNA-binding domain, TPAP lacked an approximately 100-residue C-terminal sequence carrying one of two bipartite-type nuclear localization signals, and part of a Ser/Thr-rich domain found in PAP II. Recombinant TPAP produced by an in vitro transcription/translation system was capable of incorporating the AMP moiety from ATP into an oligo(A)(12) RNA primer in the presence of MnCl(2). Moreover, an affinity-purified antibody against the 12-residue C-terminal sequence of TPAP recognized a 70-kDa protein in the cytoplasm of spermatogenic cells. These results suggest that TPAP may participate in the additional extension of mRNA poly(A) tails in the cytoplasm of male germ cells, and may play an important role in spermiogenesis, probably through the stabilization of mRNAs.

Amino Acid Sequence↗
PubMed2000

The transcript for a novel protein with a zinc finger motif is expressed at specific stages of mouse spermatogenesis.

The cDNA for an RNA that is expressed predominantly in mouse spermatogenic cells was cloned and characterized. It was found to encode novel zinc finger protein. We first generated a cDNA fragment from mouse osteoblastic cells by the differential display method. To our surprise, Northern blot analysis revealed that the corresponding transcript was expressed at high levels in the testis rather than in osteoblastic cells. Therefore, using this fragment as a probe, we isolated the full-length cDNA (3340 bp) from a mouse testis cDNA library. Analysis of the open reading frame of the cDNA indicated that the encoded protein was a polypeptide of 942 amino acids residues that included three distinct domains, namely, a zinc finger domain of the Cys(2)-His(2) type, four basic amino acid-rich domains, and a myosin II-homology domain. In situ hybridization indicated that the transcript was present in seminiferous tubules of adult mice. Elevated expression of the transcript during testicular development in mice was restricted to spermatocytes at the pachytene stage of meiotic prophase and to round and elongated spermatids, as indicated by Northern blot analysis and RT-PCR. Our results suggest that this novel zinc finger protein might act as a transcriptional regulator during spermatogenesis and, in particular, during meiotic division.

Amino Acid Sequence↗
PubMed2000

Reduction of cardiac endothelin-1 by angiotensin II type 1 receptor antagonist in viral myocarditis of mice.

Renin angiotensin system contributes to activation of circulating endothelin in congestive heart failure. To investigate the effects of angiotensin II receptor antagonist and angiotensin converting enzyme inhibitors (ACEI) on the levels of endothelin-1 (ET-1), we administered orally angiotensin II type 1 receptor (AT1) antagonist, L-158,809 (ATA) (6, 1.2 and 0.12 mg/kg/day), enalapril (1 mg/kg/day) and captopril (7.5 mg/kg/day) for 14 days to mice with viral myocarditis, beginning 7 days after encephalomyocarditis virus (500 pfu/mouse) inoculation. Plasma ET-1, cardiac ET-1, heart weight (HW) and HW/ body weight (BW) ratio were examined and compared with infected untreated mice. Moreover, the HW (mg) and HW/BW (x 10(-3)) ratio were significantly (P<0.05) reduced in mice treated with ATA and ACEIs in comparison with infected control. ACEIs and higher dosed of ATA reduced myofiber hypertrophy. Both of plasma and cardiac ET-1 proteins were significantly elevated in infected control compared with uninfected normal mice. Plasma ET-1 was significantly (P<0.01) reduced in mice with three different concentrations of ATA but were not decreased in mice with captopril or enalapril compared with infected control. The expression of endothelin-1 mRNA was significantly reduced in mice with ATA in comparison with infected untreated mice by competitive RT-PCR. ATA reduced ET-1 protein and mRNA in the myocardium of mice with myocarditis, improving congestive heart failure and myofiber hypertrophy. We suggest the effect of ATA on the reduction of endothelin has a different pathway from angiotensin converting inhibitor and that ATA seems to be a useful agents for congestive heart failure due to viral myocarditis.

Angiotensin II↗
PubMed2000

Immunolocalization of dystrobrevin in the astrocytic endfeet and endothelial cells in the rat cerebellum.

Dystrobrevin is a newly discovered dystrophin-associated protein that is classified as alpha- and beta-dystrobrevin. Previous studies reported that dystrophin, utrophin, syntrophin and beta-dystroglycan were expressed in the cerebellum. In the present study, we examined cellular and subcellular localization of dystrobrevin in the adult rat cerebellum immunohistochemically. Confocal microscopy showed that dystrobrevin was expressed around blood vessels and under the pia mater as dystrophin, utrophin and beta-dystroglycan were. Immunoelectron microscopy demonstrated that dystrobrevin was localized not only in the astrocytic endfeet around blood vessels and under the pia mater, but also in endothelial cells. Considering the fact that dystrobrevin possesses multiple phosphotyrosine kinase residues, these data suggest that dystrobrevin plays a role in blood-brain barrier functions as a component of the dystrophin complex.

Animals↗
PubMed2000

Interglycolipid Membrane Interactions: pH-Dependent Aggregation of Nonionic Synthetic Glycolipid Vesicles.

Large unilamellar vesicles composed of a nonionic synthetic glycolipid, 1,3-di-O-phytanyl-2-O-(beta-D-maltotriosyl)glycerol exhibited a pH-dependent aggregation-disaggregation process; vesicle aggregation occurred in a lower pH region and vesicle disaggregation occurred in a higher pH region. This process was almost reversible and the aggregation threshold pH increased as NaCl concentration increased. Electrophoretic mobility measurements revealed that the glycolipid vesicles are negatively charged in the range pH 1.6-13. The change in zeta-potentials as functions of pH and NaCl concentration could be well described by the Gouy-Chapman expression of the surface charges with an assumption that the interfacial charges arise from the "adsorption" of OH(-) at the vesicle-water interface and the dissociation of hydroxyl groups of the sugar headgroup in a higher pH regime (>pH 10). The pH-dependent aggregation process was reasonably well described by the classical DLVO theory. Thus, the double-layer repulsive forces appear to be a major factor in stabilizing the glycolipid vesicle suspension. Copyright 2000 Academic Press.

Journal Article↗
PubMed2000

Craniocervical and aortic atherosclerosis as neurologic risk factors in coronary surgery.

BACKGROUND: Advanced age is associated with increased systemic atherosclerosis and is a consistent neurologic risk factor after coronary artery bypass grafting (CABG). METHODS: We studied prospectively whether varying degrees of a total atherosclerotic score derived from the brain, carotid arteries, and ascending aorta predicted postoperative neuropsychologic (NP) dysfunction and stroke in 177 elderly patients (> or = 60 years) undergoing CABG. RESULTS: Group L (low total atherosclerotic score) had rates of NP dysfunction of 25% and 4%, group I (intermediate) had rates of 33% and 22%, and group H (high) had rates of 79% and 43% on postoperative days 1 and 7, respectively (p < 0.001). The incidence of stroke was higher in group H (14.3%) than in groups I and L (7.8% and 0.9%; p = 0.013). Stepwise logistic regression analysis demonstrated the significant predictors of NP dysfunction on postoperative day 7 to be total atherosclerotic score, peripheral vascular disease, and diabetes mellitus, and those of stroke to be total atherosclerotic score, peripheral vascular disease, and hyperlipidemia. CONCLUSIONS: Perioperative evaluation of craniocervical and aortic atherosclerosis is useful to identify a high-risk patient at postoperative NP dysfunction and stroke after CABG.

Aged↗
PubMed2000

Molecular and immunological approaches to mammalian fertilization.

By means of hybridoma technology, we obtained six hydriboma cell lines producing monoclonal antibody (mAb) to porcine zona pellucid (ZP), two of which recognizes the steric structure of common antigens between porcine ZP and humans. Furthermore, we have analyzed all or partial structures of N- and O-linked sugar chains of ZP glycprotein from porcine or murine oocytes. Then, we have clarified that beta-galactose and Le(X) residues on ZP played the binding roles to sperm cells in porcine and murine fertilization. We have also succeeded Sp38 cDNA cloning from cDNA library of porcine testis. We found that Sp38 protein bind to porcine ZP2 and expressed in murine and human sperm cells. Corresponding to the presence of major histocompatibility complex (MHC) class II on murine sperm, CD4 on the murine egg plasma membrane was clearly shown by indirect IIF and immunoprecipitation test. Furthermore, the transcriptional expression of CD4/p56(lck) in eggs was confirmed by RT-PCR method. In addition, the p56(lck) associated with CD4 underneath the plasma membrane of eggs was autophosphorylated after cross-linking of CD4 with anti CD4 mAb. The binding between eggs or Sf9-CD4 cells labeled with anti-CD4 mAb and sperm cells labeled with anti-monomorphic region of class II mAb was completely blocked. Considering these findings together with the fact that an interspecies' heterogeneity is present in CD4 amino acid sequence at the interactive site with class II, we elucidated that one of species' specific intercellular adhesions between two gametes at the fusion step in fertilization is definitely mediated by class II located on the posterior region of sperm head and CD4/p56(lck) complex on the plasma membrane of egg.

Amino Acid Sequence↗
PubMed2000

Mycolic acids from Rhodococcus, Gordonia, and Dietzia.

The mycolic acids from 11 species of Rhodococcus, seven species of Gordonia, and one species of Dietzia were analyzed using capillary gas chromatography and mass spectrometry (GLC/MS). All strains tested in this study were divided into three groups according to the degree of double bonds and the average carbon number (Av.Nc.) of their mycolic acids. The genus Gordonia belongs to the first group possessing an Av.Nc. in the upper 50s and 60s with 0 to 5 double bonds. Some Rhodococcus species possessed Av.Nc. in the 40s with a variety of distributions of polyunsaturated fatty acids from 0 to 4. The rest of the Rhodococcus species and the genus Dietzia possessed Av.Nc. in the 30s with saturated fatty acids. We previously reported on Nocardia strains whose Av.Nc. were in the 50s. Considering the identification of mycolic acid-containing Actinomycetales at the generic level, the Av.Nc. proved to be useful as a means of differentiating the genera Rhodococcus, Gordonia and Nocardia. The genus Dietzia was found to have its own characteristic constitution of mycolic acid molecular species. The mycolic acids from D. maris 58001T were characterized by an almost equal amount of constituents of even- and odd-numbered carbon chains, whereas the major components of mycolic acids in all other strains had even-numbered carbon chains. Another characteristic of Dietzia was some even-numbered mycolic acids which contained odd-numbered straight chains with odd-numbered alpha-branches. These characteristics indicated that Dietzia might possess a novel fatty acid biosynthesis system.

Actinomycetales↗