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Biomedical subjects

Y Endo

Publications and source records attributed to Y Endo.

At least 415 records · Page 23Linked to original sources
PubMed1993

Experimental immunoglobulin A nephropathy induced by gram-negative bacteria.

A study was conducted to determine whether intraperitoneal and oral administration of formalin-fixed gram-negative bacteria induced immunohistologically and ultrastructurally evident glomerular deposition of IgA and C3 in C3H/HeN mice. Separate treatments with strains of Pseudomonas aeruginosa, Escherichia coli, Haemophilus influenzae, Klebsiella pneumoniae, and two kinds of lipopolysaccharide (LPS) were used. Two mice in each treatment group were sacrificed at 10, 20 and 30 weeks of age to examine sequential glomerular changes. In addition to the intraperitoneal administration (IP) groups receiving whole formalin-fixed bacterial cells, cell precipitate and supernatant fractions of each bacterial strain after sonication were injected intraperitoneally once a week, and the mice were sacrificed at 30 weeks of age. Sequential quantitation or IgG, IgA or IgM in serum and the isotypes specific for each of the bacterial strains or LPS administered was performed by ELISA. The incidence of immunofluorescence positivity for glomerular IgA and C3 was 37-71 and 37-66.7%, respectively, in the IP groups that had received bacterial cells of each strain, which was significantly higher than that in the IP groups given LPS or in the controls. These results suggest that cell wall components common among gram-negative bacteria, other than LPS, play a major role in the glomerular deposition of IgA and C3. This is the first use of gram-negative bacteria to establish an active model of IgA nephropathy.

Administration, Oral↗
PubMed1993

[The relation of ideal self to perception of self and others].

One hundred and twelve (112) junior high school students made ratings of their ideal and actual selves, and of other persons of same sex whom they liked or disliked, using uni-polar scales of 42 positive and 42 negative traits words. Positive and negative ideal-self rating scores correlated with those for actual-self and others. At the same time, rating scores on important traits for each subject which gained the highest score in ideal-self rating differed among the actual self and the liked other and disliked other--the liked other was rated more positively than the disliked other, though self-esteem affected relative positiveness of actual self to liked or disliked others. However, no such differences were found on unimportant traits which gained lower scores in ideal-self rating. These results seem to indicate that both positive and negative ideal selves provide cognitive framework for perception of self and others.

Adolescent↗
PubMed1993

[Studies of combined treatment of radiofrequency hyperthermia with anticancer agents or irradiation for invasive bladder cancer].

Using an in vitro colony forming assay system, the cytotoxic effects of anticancer agents alone, adriamycin (ADM) and bleomycin (BLM), and the combined effects of hyperthermia and anticancer agents on cultivated KK-47 cells were investigated. When the hyperthermia was combined with various concentrations of ADM ranging from 0.005 to 0.1 microgram/ml and BLM from 0.01 to 1.0 microgram/ml, enhanced cell killing effects were obtained at the concentration of less than 0.02 microgram/ml of ADM and with an increase of BLM concentration. In DNA specimens obtained from the livers of chick embryos inoculated with human tumor cultivated cells, the polymerase chain reaction technique was used to amplify a DNA fragment specific to the beta-globin gene. By detecting these amplified DNA fragments, the feasibility of efficiently detecting metastatic cells present in chick embryo was demonstrated in vivo. Hyperthermic therapy showed inhibitory effects on the growth of metastasized cultivated cells in a thermal dose-dependent manner. Combination therapy of ADM, mitomycin and carboplatin and hyperthermia had an enhanced inhibitory activity on the growth of metastasized cultivated human tumor cells derived from bladder cancer. Hyperthermia using radiofrequency-capacitive heating in combination with irradiation or anticancer agents, was performed in a total of 56 patients with T2 to T4 invasive urinary bladder cancer. A tumor regression rate of 50 percent or more was obtained in 21 of these 56 patients. We have to follow up the patients for longer periods more precisely to evaluate the role of these treatments.

Adult↗
PubMed1993

[Synthesis of renin and angiotensin-converting enzyme in human heart].

The renin-angiotensin system (RAS) is known as a system which constricts vessels and enhances renal retention of sodium and water to raise the blood pressure. Recent studies have shown that the RAS is related to pathogenesis of cardiovascular diseases: 1) angiotensin-converting enzyme (ACE) inhibitor has been known to regress the cardiac hypertrophy, 2) high renin activity before treatment of hypertension has been reported to be one of the risk factors of myocardial infarction, 3) and there was a study that the gene expression of ACE was related to the susceptibility to myocardial infarction. Recently, in addition to the circulating RAS, the existence of the tissue RAS in various organs has been demonstrated. However, the existence of the tissue RAS in the human heart and its pathophysiological significance have not been fully investigated. To confirm the existence of the tissue RAS in the human heart, and clarify its pathophysiological role, we focused on the important elements of the system, renin and ACE, and studied the presence of renin and ACE mRNAs and their proteins in the human autopsied hearts. Samples were taken from the organs from 15 cases without heart disease. Renin mRNA was examined using reverse transcription-polymerase chain reaction. In all of 15 cases, renin mRNA was detected in the right atrium, but not in the left ventricle. Renin protein was found both in the right atrium and the left ventricle by Western blot. In addition to renin, ACE mRNA was also detected both in the right atrium and left ventricle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

The biosynthesis of a cytotoxic protein, alpha-sarcin, in a mold Aspergillus giganteus. I. Synthesis of prepro- and pro-alpha-sarcin in vitro.

The biosynthesis of alpha-sarcin, a ribosome inactivating protein (16.9 KDa) was studied in a mold Aspergillus giganteus. The fungus begins to secrete alpha-sarcin after reaching a stationary phase around 50 h of culture. The synthesis of alpha-sarcin was shown to be induced at the transcriptional level since the mRNA level of alpha-sarcin, titrated by immuno-precipitation with anti-alpha-sarcin antibodies of translation products in wheat germ cell-free system, was increased synchroniously with the production of the protein. The immuno-precipitates specific for alpha-sarcin contained two species of proteins of 22.5 and 18.5 KDa. The former was localized in the supernatant and the latter was segregated in the microsomes of the wheat germ system. The 22.5 KDa protein was thought to be the primary product of alpha-sarcin, although N-terminal methionine was removed, because it was the only product when the microsomes were solubilized by Triton X-100 prior to translation in the cell-free system. These results indicate that alpha-sarcin is synthesized as 22.5 KDa prepro-alpha-sarcin and is processed cotranslationary into 18.5 KDa pro-alpha-sarcin in endoplasmic reticulum as usual secretary proteins.

Aspergillus↗
PubMed1993

Production of dihydrofolate reductase by an improved continuous flow cell-free translation system using wheat germ extract.

We have examined the characteristics of protein synthesis in an improved continuous flow cell-free translation system prepared from wheat germ extract with dihydrofolate reductase mRNA as the translated message. Continuous buffer flow and separation of the product from the reaction mixture were accomplished by the use of a modified Amicon ultrafiltration chamber as the reaction vessel. The system worked for 19 hours and produced 1.52 nmol (27.4 micrograms) of enzymatically active dihydrofolate reductase.

Base Sequence↗
PubMed1993

The biosynthesis of a cytotoxic protein, alpha-sarcin, in a mold of Aspergillus giganteus. II. Maturation of precursor form of alpha-sarcin in vivo.

Since Aspergillus giganteus ribosomes are sensitive to their own product, alpha-sarcin, we studied how resistance of protein synthesizing machinery is conferred in the cells. Immunoblotting analysis of a cell-extract prepared from mycelia of alpha-sarcin-producing phase showed two anti-alpha-sarcin reactive proteins which have molecular weights of 18.5 KDa and 16.9 KDa. The former and the latter were identified as the precursor and the mature forms of alpha-sarcin, respectively. Electronmicroscopic observation examining the location in situ by labeling with protein A-gold suggested that alpha-sarcin-related proteins are exclusively localized in large and small vacuoles. The small vacuoles, distributed near cell wall, appear to be involved in maturation and in the secretion of the protein. The present results suggested that alpha-sarcin is synthesized in an inactive precursor form and segregated in the membrane compartment through the synthesis and the maturation of alpha-sarcin in the cells.

Aspergillus↗
PubMed1993

Ribosomal RNA identity elements for recognition by ricin and by alpha-sarcin: mutation in the putative CG pair that closes a GAGA tetraloop.

Alpha sarcin is a ribonuclease that cleaves the phosphodiester bond on the 3' side of G4325 in 28S rRNA; ricin A-chain is a RNA N-glycosidase that depurinates the 5' adjacent A4324. These single covalent modifications inactivate the ribosomes. An oligoribonucleotide that reproduces the structure of the sarcin/ricin domain in 28S rRNA was synthesized and mutations were constructed in the 3'C and the 5'G that surround the GAGA tetrad that has the site of toxin action. Analysis indicates that catalysis by ricin requires a Watson-Crick pair to shut off a putative GAGA tetraloop, whereas, alpha sarcin does not. One interpretation is that there are alternate conformations of the sarcin/ricin domain in 28S rRNA and that one of the conformers is recognized by sarcin and the other by ricin A-chain. This switch in the structure could underlie the translocation of peptidyl-tRNA from the A to the P site and the vectoral displacement of mRNA one codon during elongation.

Base Sequence↗
PubMed1993

[Effect of epidermal growth factor (EGF) on mouse sperm capacitation].

The effect of epidermal growth factor (EGF) on the kinetics of mouse sperm capacitation was examined. The chlortetracycline (CTC) fluorescence assay was used to monitor capacitated sperm, featuring a B pattern. One hundred ng/ml EGF significantly stimulated capacitation at 15 minutes after the addition. However, 0.1 pg/ml EGF did not stimulate capacitation. EGF affected neither the motility nor the appearance of the S or AR pattern. The EGF-induced stimulation of capacitation was attenuated by 20 micrograms/ml genistein, an inhibitor of protein tyrosine kinase, or by 100 ng/ml thapsigargin, a non-phorbol tumor promoter, which inhibits EGF action by enhancing phosphorylation of the threonine 669 residue of the EGF-receptor. However, 3 ng/ml 12-O-tetradecanoly phorbol 13-acetate (TPA), a stimulator of protein kinase C, did not attenuate the appearance of the B pattern enhanced by 100 ng/ml EGF. These data suggest that EGF stimulates mouse sperm capacitation by activating the tyrosine kinase of the EGF-receptor which is regulated by multisite phosphorylation.

Animals↗
PubMed1993

[Prevention of postoperative recurrence after hepatic resection for metastatic colorectal cancer by adjuvant locoregional chemotherapy].

Postoperative adjuvant locoregional chemotherapy was performed on patients who underwent hepatic resection for metastatic colorectal cancer. To prevent recurrence in the residual liver after hepatic resection. 7 patients received intra-hepato-arterial infusion of MMC, 5-fluorouracil (5-FU), doxorubicin + Lipiodol emulsion. Sixteen cases did not receive such treatment. The 1-, 2- and 3-year cumulative disease free rates were 100, 80 and 40% in the patients with this adjuvant chemotherapy, against 61.4, 54.6 and 28.1% in those without this locoregional therapy, respectively. The 1-, 2- and 3-year cumulative survival rates were 100, 100 and 60% in the TAI-E group, and 73.7, 63.3 and 63.3% in the patients without TAI-E, respectively. Postoperative adjuvant locoregional chemotherapy is considered effective to prevent the recurrence of metastatic colorectal cancer in the residual liver after hepatectomy.

Aged↗
PubMed1993

[Evaluation of the combination of chemotherapy with etoposide, adriamycin and cisplatin (EAP) in advanced or recurrent gastric cancer].

EAP therapy was performed on 30 cases of advanced or recurrent gastric cancer between September 1987 and July 1991. The clinical responses of 15 trial patients were evaluated. The overall response rate was 40.0% (CR, one case; PR 5 cases). The results were thus not as favorable as that reported by Preusser et al. On the contrary, with such a poor response rate, this treatment did not lead to a prolonged life span (mean survival time; 5.6 months, median survival time; 4 months). Side effects, such as myelosuppression, appetite loss, nausea, vomiting, liver dysfunction, renal dysfunction, and alopecia, were also observed. Myelosuppression was a dose-limiting factor. The rhG-CSF proved in 4 cases to be a clinically useful tool against the neutropenia induced by this treatment. It may be concluded that EAP should be given to the following selected patients: (1) those whose condition is not so far advanced: (2) those who have not received many other forms of treatment; and (3) those in excellent general physical condition.

Adult↗
PubMed1993

Effects of modulators of protein kinase C on human sperm capacitation.

OBJECTIVE: To examine the effects of stimulators or inhibitors of protein kinase C on capacitation and protein phosphorylation in human sperm. DESIGN: Capacitated sperm treated with or without modulators of protein kinase C were monitored by the chlortetracycline fluorescence assay. Capacitation was confirmed by the ability of sperm to undergo the acrosomal reaction in response to mouse zonae pellucidae. 32P-labeled sperm phosphoproteins were analyzed by one-dimensional gel electrophoresis to detect the effect of protein kinase C stimulator, 12-O-tetradecanoyl-phorbol-13-acetate, on protein phosphorylation. RESULTS: The treatment of sperm with protein kinase C stimulators resulted in the following: [1] the rapid appearance of the clear perimeter pattern, featuring distribution of fluorescence over the entire head exhibiting a bright perimeter and bright midpiece; [2] an accelerated ability to undergo the acrosomal reaction; and [3] an enhanced phosphorylation of 57.5-kd sperm phosphoprotein. Furthermore, these stimulatory effects were inhibited by protein kinase C inhibitors. CONCLUSION: Protein phosphorylation mediated by protein kinase C may be involved in the regulation of human sperm capacitation.

Acrosome↗
PubMed1992

Ribosomal RNA identity elements for ricin A-chain recognition and catalysis. Analysis with tetraloop mutants.

Ricin is a cytotoxic protein that inactivates ribosomes by hydrolyzing the N-glycosidic bond between the base and the ribose of the adenosine at position 4324 in eukaryotic 28 S rRNA. Ricin A-chain will also catalyze depurination in naked prokaryotic 16 S rRNA; the adenosine is at position 1014 in a GAGA tetraloop. The rRNA identity elements for recognition by ricin A-chain and for the catalysis of cleavage were examined using synthetic GAGA tetraloop oligoribonucleotides. The RNA designated wild-type, an oligoribonucleotide (19-mer) that approximates the structure of the ricin-sensitive site in 16 S rRNA, and a number of mutants were transcribed in vitro from synthetic DNA templates with phage T7 RNA polymerase. With the wild-type tetraloop oligoribonucleotide the ricin A-chain-catalyzed reaction has a Km of 5.7 microM and a Kcat of 0.01 min-1. The toxin alpha-sarcin, which cleaves the phosphodiester bond on the 3' side of G4325 in 28 S rRNA, does not recognize the tetraloop RNA, although alpha-sarcin does affect a larger synthetic oligoribonucleotide that has a 17-nucleotide loop with a GAGA sequence; thus, there is a clear divergence in the identity elements for the two toxins. Mutants were constructed with all of the possible transitions and transversions of each nucleotide in the GAGA tetraloop; none was recognized by ricin A-chain. Thus, there is an absolute requirement for the integrity of the GAGA sequence in the tetraloop. The helical stem of the tetraloop oligoribonucleotide can be reduced to three base-pairs, indeed, to two base-pairs if the temperature is decreased, without affecting recognition; the nature of these base-pairs does not influence recognition or catalysis by ricin A-chain. If the tetraloop is opened so as to form a GAGA-containing hexaloop, recognition by ricin A-chain is lost. This suggests that during the elongation cycle, a GAGA tetraloop either exists or is formed in the putative 17-member single-stranded region of the ricin domain in 28 S rRNA and this bears on the mechanism of protein synthesis.

Base Sequence↗
PubMed1992

Active conformation of a tumor promoter, teleocidin. A molecular dynamics study.

Telecidins are potent tumor promoters, having a nine-membered lactam structure. Teleocidins and their small-molecular-sized active congeners (indolactams) are known to exist in an equilibrium between at least two conformational states, the twist and the sofa form. Molecular dynamics (MD) calculations were performed on four indolactams, in order to examine the relationships between preferred ring conformations and the biological activities. It was shown that the tumor-promoting activities are closely related with the existence ratio of the sofa form among 10 possible conformations. This implies that the sofa form is the active ring conformation, which is compatible with the previous result obtained independently from the superposition of teleocidin and phorbol ester. The predicted ratios of conformers for each indolactam were in good agreement with those observed by NMR spectral analysis. The high-temperature MD method proved to be very useful for predicting the preferred structures of these cyclic compounds, in which the overall stabilities are strongly influenced by the conformations of substituent groups on the ring.

Carcinogens↗