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Biomedical subjects

A Yamazaki

Publications and source records attributed to A Yamazaki.

At least 127 records · Page 7Linked to original sources
PubMed1989

Enhancement of phosphatidylinositol turnover and cyclic nucleotide accumulation by chronic anethole trithione treatment in rat submaxillary glands.

The effect of chronic treatment with anethole trithione (ANTT) on the phosphatidylinositol (PI) turnover and cyclic (c)AMP and cGMP accumulation in rat submaxillary glands (SMG) has been compared with the effect of chronic treatment with atropine and a cholinesterase inhibitor, diisopropylfluorophosphate (dyflos, DFP). Experiments were performed 24, 48 and 24 h after the last dose of ANTT, atropine and dyflos, respectively. ANTT and atropine enhanced carbachol-stimulated [32P] incorporation into phosphatidic acid in the SMG slices, while dyflos showed no effect. Pilocarpine-stimulated in-vivo incorporation of [3H]myoinositol into inositol phosphates was significantly enhanced by ANTT, but not by atropine or by dyflos. Phospholipase C-dependent hydrolysis of phosphatidylinositol 4,5-bisphosphate was significantly enhanced by ANTT and atropine, but not by dyflos. Pilocarpine-stimulated in-vivo accumulation of cAMP and cGMP was enhanced by ANTT and atropine, but dyflos reduced cAMP accumulation without affecting cGMP accumulation. The enhancement of PI turnover and cyclic nucleotide accumulation seems to contribute to the development of supersensitivity of the salivary gland caused by chronic treatment with ANTT and atropine, while reduction of cAMP accumulation may be responsible for the subsensitivity caused by dyflos.

Anethole Trithione↗
PubMed1989

Cloning and characterization of the gene for immunogenic protein MPB64 of Mycobacterium bovis BCG.

The gene for immunogenic protein MPB64 found in culture filtrates of only Mycobacterium tuberculosis and some strains of Mycobacterium bovis BCG was cloned by using a single-probe method and was sequenced. The gene analysis revealed that the structural gene for MPB64 consisted of 618 base pairs, and its deduced molecular weight was 22,400. Twenty-two amino acids for a putative signal peptide and 205 amino acids for the MPB64 protein were observed. In the coding region, the third letter of the codon showed a biased codon and a high G+C content (78.5%). The gene was expressed in Escherichia coli by using an E. coli expression vector. The product showed migration similar to that of the authentic MPB64 protein by electrophoresis and reacted with the polyclonal and the monoclonal antibodies raised against the MPB64 protein. The strict specificity of MPB64 could be applied to immunodiagnosis of tuberculosis.

Amino Acid Sequence↗
PubMed1989

Clinical observations on fertile males with varicocele.

During the clinical observation of 32 fertile cases with varicocele interesting findings were made. Normal semen, a sperm density above 40 million/ml and a motile sperm rate of over 60% were observed in 46.9% of the cases. Furthermore, a sperm density of more than 40 million/ml was found in 75% and a motile sperm rate of more than 50% was detected in 81.3%, indicating normal or adequate spermogram data. A difference in right-left testicular size was recognized in 35.5% (11 cases). Only 2 of the cases had oligospermia and 9 cases had normospermia. Two cases had low testosterone values and low motile sperm rates were also detected. Secondary infertility occurred in 33.3%. In 25% of the cases, scrotal scintigraphy revealed an accumulation of high radioactivity indicating venous blood pooling over the affected site in the early phase of dynamic images. In the other cases, different venous flow characteristics were detected visually.

Adult↗
PubMed1989

Improved technique of tubeless cutaneous ureterostomy and results of permanent urinary diversion.

An improved technique of tubeless cutaneous ureterostomy through a single stoma was devised by modifing the traditional cutaneous ureterostomy. Using this method, urinary diversions were performed on 12 cases with malignancies: 6 had radical cystectomy and the other 6 had pelvic exenteration. Normal bilateral ureters were observed in 11 cases in preoperative intravenous pyelography. Stomal stenosis was found in 1 case (8.3%) requiring operative stomal revision. Generally satisfactory results were obtained. This method could lower the incidence of complications. A long-term follow-up is needed, but 2 cases who have survived for more than 4 years since the operation have shown excellent results. It was thought that it would be difficult to perform tubeless cutaneous ureterostomy on normal-sized ureters, but our clinical results indicate that this method may be able to provide permanent urinary diversion.

Adult↗
PubMed1988

Immunogenic protein MPB57 from Mycobacterium bovis BCG: molecular cloning, nucleotide sequence and expression.

Using a single-probe method, we have cloned the gene for an immunogenic MPB57 protein of Mycobacterium bovis BCG. The nucleotide sequence includes an ORF of 300 base pairs encoding a protein of 99 amino acids with an Mr of 10,818. This cloned gene was expressed in an Escherichia coli expression vector to give a mature protein which reacted with a polyclonal antibody raised against MPB57.

Amino Acid Sequence↗
PubMed1988

Passage of indigestible particles of various specific gravities in sheep and goats.

1. Eight kinds of indigestible particles with specific gravities (SG) ranging from 0.92 to 1.87 (2 mm diameter and 4 mm length) were injected into the reticulo-rumen of sheep and goats in order to investigate the relation between SG and passage through the gastrointestinal tract, and the difference in passage time in the two species of animals. 2. The percentage of excreted particles significantly increased, while the percentage of ruminated particles in the excreted particles significantly decreased, as the SG increased. 3. The daily and cumulative recovery rates of particles of SG 1.38 were slower in sheep than in goats, while those with SG 0.92 were not different between species. 4. It is concluded that particles with SG higher than 1.27 would pass through the gastrointestinal tract of sheep and goats more quickly than those with SG lower than 1.21.

Animals↗
PubMed1988

Cloning and expression of the Mycobacterium bovis BCG gene for extracellular alpha antigen.

The gene for the extracellular alpha antigen of Mycobacterium bovis BCG was cloned by using a single probe restricted to G or C in the third position. This technique should have great potential for the isolation of mycobacterial antigen genes. The gene analysis revealed that the alpha antigen gene encoded 323 amino acid residues, including 40 amino acids for signal peptide followed by 283 amino acids for mature protein. This is the first report on the structure of the mycobacterial signal peptide. The promoter-like sequence and ribosome-binding site were observed upstream of the open reading frame. In the coding region, the third position of the codon showed high G + C content (86%). The gene was expressed as an unfused protein in Escherichia coli by using an E. coli expression vector. This protein, which reacted with polyclonal antibody raised against alpha antigen from Mycobacterium tuberculosis, would be applicable to the immunodiagnosis of tuberculosis.

Amino Acid Sequence↗
PubMed1988

The relaxation induced by indole and nonindole 5-HT agonists in the molluscan smooth muscle.

1. The abilities of two indole agonists and some nonindole agonists to induce relaxation of catch contraction and the influence of the agonists on cyclic AMP (cAMP) levels in the anterior byssus retractor muscle (ABRM) of Mytilus were investigated. 2. 5-MeOT (5-methoxytryptamine) and 5-MeODMT (5-methoxy-N,N-dimethyltryptamine) dose-dependently relaxed the contraction. 3. TFMPP (m-trifluoromethylphenyl piperazine), PAPP (p-amino-phenyl TFMPP) and mCPP (1-(3-chlorophenyl)piperazine dose-dependently relaxed the contraction, but 2MPP (1-(2-methylphenyl) piperazine and quipazine did not. 4. 5-MeOT (10(-6)M), 5-MeODMT (10(-6)M), TFMPP (10(-4)M), 2MPP (10(-4)M), quipazine (10(-4)M) and 8-OH-DPAT (3 x 10(-5) M) significantly reduced the cAMP levels, but PAPP (3 x 10(-4)M) and mCPP (10(-4)M) did not have any effect on cAMP levels. 5. These findings indicate that the pharmacological properties of 5-HT1-like receptors in the ABRM are similar to those of 5-HT1A receptors in mammalian tissues, and that the changes in cAMP levels induced by the agonists used are unlikely to be directly linked to the relaxation induced by them.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1988

[Two cases of urethral leiomyoma].

Two cases of urethral leiomyoma are reported. Two Japanese women 39 and 28 years old presented with the complaint of a painless mass protruding from the anterior wall of urethra to urethral meatus. The mass was firm with associated condyloma acuminatum on its surface and was easily removed by surgical excision. Sixty-four cases of urethral leiomyoma have been reported in Japan before the present cases. The majority of them were in females. The peak of incidence was in the 30th to 40th decade, suggesting the relationship of urethral leiomyoma to female sex hormones. No malignant development has been described. Judging from these findings, it appears possible to differentiate leiomyoma of urethra from caruncle, urethral prolapse or urethral carcinoma by careful inspection and palpation of a mobile firm mass under epithelium.

Adult↗
PubMed1987

The GTP-binding protein of rod outer segments. I. Role of each subunit in the GTP hydrolytic cycle.

The GTP-binding protein of Bufo marinus rod outer segments (ROS) is composed of 3 subunits: G alpha, 39,000; G beta, 36,000; and G gamma, approximately 6,500. A stepwise analysis of the GTP hydrolytic cycle (GTP binding, GTP hydrolysis, and GDP release) was facilitated by using purified subunits of the GTP-binding protein. When G alpha and G beta, gamma concentrations were held constant, the initial rate of guanosine-5'-O-(3-thiotriphosphate) (GTP gamma-s) binding to G alpha was dependent upon the amount of bleached rhodopsin present (as illuminated, urea-washed ROS disc membranes). When G alpha and the quantity of these membranes was held constant, the initial rate of GTP gamma-s binding to G alpha was markedly enhanced by increasing the amount of G beta, gamma. G beta preparations (free of G gamma) also stimulated the binding of GTP gamma-s to G alpha to the same extent as G beta, gamma preparations, suggesting that G gamma is not an essential component of the G beta, gamma-dependent stimulation of the rate of GTP gamma-s binding to G alpha. Nonlinear regression analysis revealed a single class of binding sites with an apparent stoichiometry of 1 mol of site/mol of G alpha under optimal binding conditions. Following GTP binding to G alpha, the GTP X G alpha complex dissociates from G beta, gamma which remains primarily bound to the ROS disc membranes. Moreover, while GTP remains in excess, the rates of GTP hydrolysis exhibited saturation in the presence of increasing amounts of G beta, gamma. Nonlinear regression analysis of these data argues against a direct role for G beta, gamma in the hydrolysis of GTP. Thus, both topologic and kinetic data support the concept that GTP hydrolysis is carried out by G alpha alone. After hydrolysis of GTP, the GDP X G alpha complex returned to the ROS disc membrane when G beta, gamma was present on the membrane surface, in the presence and absence of light. Without guanine nucleotides GDP release occurred in the presence of illuminated ROS disc membranes and G beta, gamma. Guanine nucleotides (GTP gamma-s approximately equal to GTP approximately equal to guanosine 5'-(beta, gamma-imido)triphosphate greater than GDP) could effectively displace GDP from G alpha under these conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1987

The GTP-binding protein of rod outer segments. II. An essential role for Mg2+ in signal amplification.

The role of Mg2+ in the GTP hydrolytic cycle was investigated by using purified subunits (G alpha and G beta, gamma) of the GTP-binding protein isolated from Bufo marinus rod outer segments (ROS). Mg2+ markedly stimulated the rate of GTP and guanosine-5'-O-(3-thiotriphosphate) (GTP gamma-s) binding to G alpha. This effect was especially striking in the presence of very small quantities of illuminated ROS disc membranes. GTP hydrolysis could occur in the absence of Mg2+, and Mg2+ increased the rate of GTP hydrolysis only about 50%. These data indicate that Mg2+ plays a fundamental role in amplification of the photon signal by markedly stimulating the rate of formation of GTP X G alpha complexes by very small amounts of illuminated rhodopsin while producing only a modest increase in the rate of GTP hydrolysis. Following hydrolysis of GTP, GDP X G alpha could reassociate with illuminated or unilluminated ROS disc membranes in the presence or absence of Mg2+. In the absence of guanine nucleotides, release of GDP from G alpha bound to illuminated disc membranes was detected in the presence or absence of Mg2+. Moreover, Mg2+ did not affect the rate of GDP release from membrane-bound G alpha. Illumination of B. marinus crude ROS disc membrane preparations markedly reduced pertussis toxin-mediated ADP-ribosylation of a 39,000 Mr (G alpha) protein in the presence but not in the absence, of Mg2+. Moreover, extensive dialysis of illuminated (but not unilluminated) crude ROS disc membranes against a Mg2+-containing buffer caused a marked reduction in the subsequent ADP-ribosylation of G alpha, even when Mg2+ was not present during the ADP-ribosylation step. This reduction was reversed by the addition of GDP or a GDP analogue (but not GMP or hydrolysis-resistant GTP analogues) during the ADP-ribosylation step. Dialysis of crude ROS disc membrane preparations (illuminated or unilluminated) against a Mg2+ -free buffer did not reduce the subsequent ADP-ribosylation of G alpha. These data indicate that Mg2+, in the presence of photolysed rhodopsin, can stimulate the release of GDP from crude preparations of ROS disc membranes. Four lines of evidence suggest that G alpha and G beta, gamma have Mg2+-binding site(s). When stored at 4 degrees C, in the absence of glycerol, G beta, gamma was more stable in the absence than in the presence of Mg2+.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenosine Diphosphate Ribose↗
PubMed1987

Calmodulin and calmodulin binding proteins in amphibian rod outer segments.

The calmodulin (CaM) content of fully intact frog rod outer segments (ROS) has been measured. The molar ratio between rhodopsin and total CaM in ROS is 800:1. This is in good agreement with the data reported for bovine ROS CaM [Kohnken, R. E., Chafouleas, J. G., Eadie, D. M., Means, A. R., & McConnell, D.G. (1981) J. Biol. Chem. 256, 12517-12522]. In the absence of Ca2+, the ROS membrane fraction contains only 4% of total ROS CaM. In contrast, in the presence of Ca2+, 15% of total ROS CaM is found in the membrane fraction. For half-maximal binding of CaM to CaM-depleted ROS membranes, 3 X 10(-7) M Ca2+ is required. This CaM binding is inhibited by trifluoperazine. CaM binding proteins in the ROS membrane fraction are identified by using two different methods: the overlay method and the use of 3,3'-dithiobis(sulfosuccinimidyl propionate) (DTSSP), a bifunctional cross-linking reagent. Ca2+-dependent CaM binding proteins with apparent molecular weights of 240,000, 140,000, 53,000, and 47,000 are detected in the ROS membrane fraction by the overlay method. Anomalous, Ca2+-independent CaM binding to rhodopsin is also detected with this method, and this CaM binding is inhibited by the presence of Ca2+. With the bifunctional cross-linking reagent, DTSSP, three discrete proteins with molecular weights of 240,000, 53,000, and 47,000 are detected in the native ROS membrane fraction. CaM binding to rhodopsin is not detected with this method. Moreover, while the Mr 140,000 band is not detected with DTSSP, a smeared band with a molecular weight between 78,000 and 93,000 is identified (with DTSSP) in the ROS membrane fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗