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Biomedical subjects

Y Fujii

Publications and source records attributed to Y Fujii.

At least 505 records · Page 28Linked to original sources
PubMed1997

Evaluation of transrectal voiding ultrasonography in men with micturition difficulties without apparent organic obstruction of the lower urinary tract.

OBJECTIVE: To examine whether transrectal voiding ultrasonography (TRVUS) can evaluate voiding movement in men with dysfunctional voiding. METHODS: Ninety-nine consecutive men complaining of voiding difficulties without benign prostatic hyperplasia, prostatic cancer, severe bladder neck contracture and urethral stricture received uroflowmetry and TRVUS. Those who had abnormal findings on both uroflowmetry and TRVUS underwent subsequent cystometry combined with electromyography (EMG) to confirm the presence of dysfunctional voiding. RESULTS: Uroflowmetry indicated abnormal findings in 31 of the 99 patients, and TRVUS demonstrated abnormal movements of the posterior urethra during voiding in all of these 31 patients and 11 of the other 68 patients whose uroflowmetry did not indicate abnormality. TRVUS findings of the former 31 were divided into type E (the external urethral sphincter closed or intermittently opened while the bladder neck manifested an opening movement of > 7 mm during voiding in 20) and type I (both the bladder neck and external urethral sphincter manifested an intermittent movement of < 7 mm in 11). Subsequent cystometry combined with EMG in the 31 patients who had abnormal findings on both uroflowmetry and TRVUS revealed overactivity of the external urethral sphincter (OS) and underactivity of the detrusor (UD) in 85 and 35% of type-E group and 55 and 73% of type-I group, respectively. Type E included significantly more OS without UD than type I (65 vs. 18%; p = 0.0233). All of type-E (20/20) and 91% of type-I (10/11) patients had voiding difficulty which resulted from either OS or UD, while a very limited number of patients (4/31) manifested neurological symptoms such as paraplegia except for voiding difficulties. CONCLUSIONS: Both uroflowmetry and TRVUS are easy and useful methods to evaluate dysfunctional voiding in men, especially when neural disorders or organic obstruction of the lower urinary tract are not apparent.

Aged↗
PubMed1997

Biological behaviour of 6-chloro-2',3'-dideoxyguanosine and 6-chloro-2',3'-dideoxyinosine in the brains of mice.

By using tissue and blood from mice and mice themselves, biological behavior of 6-chloro-2',3'-dideoxyguanosine (6-Cl-ddG) and 6-chloro-2',3'-dideoxyinosine (6-Cl-ddI) was examined in vitro and in vivo. Both compounds resemble each other in chemical structure. They are converted to ddG and ddI, respectively, by adenosine deaminase in the cells, and express their anti-HIV activity in vitro. According to our recent data about their biological behaviour in vivo; however, it was revealed that they are fairly different especially as the agent working in the brain. After injection of each drug into the body of mice, ddG, or metabolite of 6-Cl-ddG, was observed in the brain, while ddI was not found there.

Adenosine Deaminase↗
PubMed1996

Synthesis and phospholipase A2 inhibitory activity of thielocin B3 derivatives.

We prepared several types of derivatives of thielocin B3, a very potent naturally occurring inhibitor for human nonpancreatic secretory PLA2 (sPLA2-II), and conducted a structure-activity relationship study to identify potent sPLA2-II inhibitors with the aim of developing antiinflammatory drugs. The total number of aromatic rings is critical for sPLA2-II inhibition, and the best result was obtained in the case of six rings. The structure of the central part of the inhibitors was not specific, and potent inhibitors were found among the sulfide, sulfone, ether, methylene, and amino derivatives. Although a diester of the terminal carboxylic acid lost its inhibitory activity, having both of the carboxylic acids was not necessary for expression of activity, as illustrated by a glycine derivative with the benzyl ester group 36. Among the newly synthesized derivatives, 18, 20, 29, and 36 showed very potent human sPLA2-II inhibitory activity comparable to that of natural thielocin B3. Their IC50 values are in the range 0.069-0.14 microM, and they are a class of compounds showing the most potent sPLA2-II inhibition to date.

Benzhydryl Compounds↗
PubMed1996

Clustered localization of oligomeric Nef protein of human immunodeficiency virus type 1 on the cell surface.

We studied human immunodeficiency virus type 1 (HIV-1) Nef protein biochemically and histologically. HIV-1 Nef, derived from baculosystem and from cells infected with HIV-1, formed homomeric monomers, dimers, trimers, and further polymers. These oligomers were non-covalently associated. In cells infected with HIV-1, Nef molecules were clustered at the cell surface as well as cytoplasm. Our previous results have indicated that the Nef on the surface of cells infected with HIV-1 is cytotoxic against uninfected CD4+ T cells. Thus, it is very likely that the HIV-1-mediated cytotoxic reaction is due, at least in part, to the clustered localization of oligomeric Nef on the cell surface.

Animals↗
PubMed1996

Quantitative determination of cardiac glycosides in Digitalis lanata leaves by reversed-phase thin-layer chromatography.

An analytical method for the determination of cardiac glycosides in Digitalis lanata leaves by reversed-phase thin-layer chromatography (RP-TLC) was developed. The procedure consisted of extraction of dry leaf powder with 50% methanol and clean-up by Sep-Pak cartridges prior to RP-TLC analysis. RP-TLC was performed on an octadecylsilyl bonded silica gel plate, using a developing solvent of acetonitrile-methanol-0.5 M NaCl (1:1:1) for primary glycosides and acetonitrile-methanol-0.5 M NaCl (12:7:9) for secondary glycosides. The plate was scanned with a reflectance densitometer at 225 nm. The quantitation was carried out by the internal standard method. The present method is reliable and relatively simple for the determination of cardiac glycosides in Digitalis lanata leaves.

Cardiac Glycosides↗
PubMed1996

Soluble Nef antigen of HIV-1 is cytotoxic for human CD4+ T cells.

We have previously shown that Nef-gene 10 fusion protein induces marked growth arrest of human primary CD4+ T cells. Here, in vitro cytostatic and cytotoxic activities of human immunodeficiency virus type 1 (HIV-1) Nef against CD4+ T cells were extensively investigated. Growth of human CD4+ cells was inhibited significantly just by the addition of purified full-length Nef to cultures. When Nef was cross-linked by anti-Nef antibodies, it became very cytocidal for CD4+ T cells. A high percentage of sera from HIV-1-infected individuals contained soluble Nef. Thus, soluble Nef in vivo may play an important role in immunodysfunction of CD4+ T lymphocytes in HIV-1 infection.

CD4-Positive T-Lymphocytes↗
PubMed1996

Human immunodeficiency virus type 1 Nef protein on the cell surface is cytocidal for human CD4+ T cells.

We have previously shown that the carboxyl-terminal region of human immunodeficiency virus type 1 (HIV-1) Nef antigen present on the outer surface of virus-infected cells has affinity for uninfected T cells. Here, the in vitro cytotoxic potential of HIV-1 Nef on the T cell surface against CD4+ T cells was investigated in detail. Human T cells expressing Nef on the cell surface by transfection with non-infectious mutant HIV-1 proviruses were demonstrated to kill CD4+ T cells efficiently. Furthermore, it was shown that the carboxyl-terminal portion of Nef was cytotoxic for CD4+ T cells and that monoclonal antibody against the carboxyl-terminal region of Nef inhibited Nef induced-cytolysis. Thus, we concluded that Nef protein on CD4+ T cells may play an important role in the specific loss of CD4+ T lymphocytes during HIV-1 infection.

CD4-Positive T-Lymphocytes↗
PubMed1996

Three-dimensional structure of a DNA repair enzyme, 3-methyladenine DNA glycosylase II, from Escherichia coli.

The three-dimensional structure of Escherichia coli 3-methyladenine DNA glycosylase II, which removes numerous alkylated bases from DNA, was solved at 2.3 A resolution. The enzyme consists of three domains: one alpha + beta fold domain with a similarity to one-half of the eukaryotic TATA box-binding protein, and two all alpha-helical domains similar to those of Escherichia coli endonuclease III with combined N-glycosylase/abasic lyase activity. Mutagenesis and model-building studies suggest that the active site is located in a cleft between the two helical domains and that the enzyme flips the target base out of the DNA duplex into the active-site cleft. The structure of the active site implies broad substrate specificity and simple N-glycosylase activity.

Amino Acid Sequence↗
PubMed1996

Targeted disruption of the Rad51 gene leads to lethality in embryonic mice.

The mouse Rad51 gene is a mammalian homologue of the Escherichia coli recA and yeast RAD51 genes, both of which are involved in homologous recombination and DNA repair. To elucidate the physiological role of RAD51 protein, the gene was targeted in embryonic stem (ES) cells. Mice heterozygous for the Rad51 null mutation were intercrossed and their offspring were genotyped. There were no homozygous (Rad51-/-) pups among 148 neonates examined but a few Rad51-/- embryos were identified when examined during the early stages of embryonic development. Doubly knocked-out ES cells were not detected under conditions of selective growth. These results are interpreted to mean that RAD51 protein plays an essential role in the proliferation of cell. The homozygous Rad51 null mutation can be categorized in cell-autonomous defects. Pre-implantational lethal mutations that disrupt basic molecular functions will thus interfere with cell viability.

Alleles↗
PubMed1996

Membrane-type matrix metalloproteinase 1 is a gelatinolytic enzyme and is secreted in a complex with tissue inhibitor of metalloproteinases 2.

The processing mechanism and gelatinolytic activity of the membrane-type matrix metalloproteinase 1 (MT-MMP-1) were examined by expressing in COS-1 cells a deletion mutant of MT-MMP-1 lacking the trans-membrane domain (delta MT1) and its site-directed mutant with a furin-resistant sequence in the propeptide domain (mutant delta MT1). delta MT1, but not mutant delta MT1, was processed to an active form and exhibited gelatinolytic activity as seen using gelatin zymography. delta MT1 isolated in a complex form with tissue inhibitor of metalloproteinases 2 (TIMP-2) from the stable transfectants demonstrated the NH2-terminal sequence of Ala113-IIe-Gln-Leu, indicating cleavage at one amino acid down-stream from the furin recognition sequence. The delta MT1/TIMP-2 complex formed a ternary complex with proMMP-2 through the COOH termini of TIMP-2 and proMMP-2. A human breast carcinoma cell line (MDA-MB-231 cells) also secreted MT-MMP-1 into culture media, which was purified in a complex form with TIMP-2 and showed gelatinolytic activity as seen using zymography. These results demonstrate for the first time that MT-MMP-1 is a gelatinolytic enzyme and secreted from cells in a complex with TIMP-2, which can form a ternary complex of MT-MMP-1/TIMP2/proMMP-2.

Animals↗
PubMed1996

Identification of protein synthesis elongation factor G as a 4.5 S RNA-binding protein in Escherichia coli.

Escherichia coli 4.5 S RNA is metabolically stable and abundant. It consists of 114 nucleotides, and it is structurally homologous to domain IV of mammalian signal recognition particle (SRP) RNA. In this study, we found two 4.5 S RNA-binding proteins in cell extracts by means of a gel mobility shift assay. One protein was identified as Ffh, which has been characterized as 4.5 S RNA-binding protein. The other protein was separated from Ffh by two consecutive column chromatographic elutions and by monitoring the 4.5 S RNA binding activity. After the second chromatography, a dominant protein with an approximate molecular weight of 78,000 was associated with 4.5 S RNA binding activity. A sequence of the NH2-terminal 19 residues of the 78-kDa protein was completely identical to that of the protein elongation factor G (EF-G) of E. coli, and further it cross-reacted with antiserum against E. coli EF-G. The results obtained using a synthetic oligo RNA corresponding to the 23 S rRNA defining the EF-G binding site indicated that 4.5 S RNA and 23 S rRNA are competitive in 4.5 S RNA binding and that a decanucleotide sequence conserved between them serves as a binding site for EF-G. Conservation of the SRP RNA binding activity of EF-G from Bacillus subtilis suggests that the binding of EF-G to SRP RNA is essential for its function.

Amino Acid Sequence↗
PubMed1996

A comparative study on developmental capacity to blastocysts derived from 1-and 2(3)-cell bovine embryos after in vitro maturation and fertilization.

The present study was conducted to compare the developmental capacity of 1-and 2(3)-cell embryos after 18 and 30 h of fertilization, and blastocyst cell number and in vitro survival after freezing and thawing of bovine blastocysts derived from the 1-and 2-cell embryos. Oocytes were matured and fertilized by conventional IVM/IVF methods. After 18 or 30 h of fertilization, 1-cell embryos (18 h-fertilization) or 1- and 2(3)-cell embryos (30 h-fertilization) were cultured for 8 or 10 d in synthetic oviduct fluid medium (SOFM) supplemented with 10% human serum (HS), minimum essential medium (MEM) essential or nonessential amino acids and glutamine. The separate culture of 1- and 2(3)-cell embryos after 30 h of fertilization showed higher (p < 0.01) cleavage, development to expanded and hatched blastocysts than culture of 1-cell embryos after 18 h of fertilization. Two-cell embryos of 30 h-fertilization group had higher developmental capacity to expanded and hatched blastocysts than 1-cell embryos at 18 or 30 h after insemination (Experiment I). However, there was no significant difference in the mean cell number of blastocysts derived from the culture of 1-cell and 2(3)-cell embryos, respectively (Experiment II). The in vitro survival or hatching after freezing and thawing of blastocysts was significantly affected by embryonic quality before freezing, but did not significantly differ with blastocysts derived from 1- and 2(3)-cell embryos after 18 or 30 h of fertilization. The results indicate that the culture of 2(3)-cell embryos after 30 h of fertilization is an effective method to produce more transferable embryos (blastocysts) in bovine IVM, IVF and IVC techniques.

Journal Article↗
PubMed1996

Inversely correlated expression of p16 and Rb protein in non-small cell lung cancers: an immunohistochemical study.

Cdk4-mediated phosphorylation of Rb protein is inhibited by p16, a product of a possible tumor suppressor gene. We examined the expression of p16 and Rb protein by means of immunohistochemistry in 61 non-small cell lung cancers and have demonstrated an inverse relationship between the expression of p16 and Rb protein: 28/30 specimens that did not stain for p16 stained for Rb and 21/31 p16-positive specimens did not stain for Rb. Only 1 of the p16-negative specimens had a mutation of exon 2 of the CDKN2 gene. Our results indirectly support the theory that p16 expression is negatively regulated by the functional Rb protein.

Base Sequence↗
PubMed1996

HLA-A null allele with a stop codon, HLA-A*0215N, identified in a homozygous state in a healthy adult.

A healthy adult having no serologically detectable HLA class I A locus antigens was identified. The parents of the individual are consanguineous. Results of a family study indicated that the individual is homozygous for the B46-Cw1-DR8.1 haplotype, which was shown to be positively associated with A*0207 in our previous study. The HLA-A null individual is healthy and exhibits no apparent immunological abnormality. Total RNAs extracted from peripheral blood were converted to cDNAs. The reverse transcriptase-polymerase chain reaction (PCR) product, which is of the same size as the normally expressed gene, was easily obtained from the cDNAs with HLA-A locus-specific primers. The nucleotide sequence of this null allele (A*0215N) was the same as that of A*0207 except for a single nucleotide substitution which resulted in a stop codon in exon 4. From its nucleotide sequence, a truncated molecule was expected to be produced; however, the immunoprecipitation study failed to detect the predicted product. Genomic DNAs from 29 unrelated individuals who expressed only one HLA-A antigen with HLA-B46, were analyzed by a PCR-sequence-specific oligonucleotide method. None of the samples possessed this stop codon. Therefore, A*0215N is likely to be a rare allele generated by a single point mutation from A*0207.

Adult↗
PubMed1996

Dynamic structure of glomerular capillary loop as revealed by an in vivo cryotechnique.

Morphological studies using immersion or perfusion fixation methods do not reveal the ultrastructure of functioning kidneys with normal circulation. A simple apparatus was developed for freezing the kidneys in vivo without stopping the blood supply, and the ultrastructure of the glomerular capillary loops was examined under different haemodynamic conditions. Mouse kidneys were frozen under normal blood flow conditions; others were frozen in the same way after ligation of the abdominal aorta at a point caudal to the renal arteries. They were then processed for the freeze-substitution or deep-etching method. Good ultrastructural preservation was obtained within about 5 microM depth from the frozen tissue surface. Functioning glomeruli with normal blood flow possessed open capillary lumens, different shapes of foot processes and atypical basement membranes with low density. Moreover, heterogeneity in width between foot processes was identified on the replica membranes. Under the acute conditions used to increase blood supply into the kidneys, the spaces between the flat foot processes became more widely dilated and the basement membrane was seen to be three-layered. The ultrastructure of glomeruli in functioning kidneys has been demonstrated for the first time by this "in vivo cryotechnique."

Animals↗