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Biomedical subjects

O Yamaguchi

Publications and source records attributed to O Yamaguchi.

At least 55 records · Page 3Linked to original sources
PubMed1996

Changes in cholinergic and purinergic neurotransmission in pathologic bladder of chronic spinal rabbit.

PURPOSE: We evaluated the changes in cholinergic and purinergic neurotransmission in pathologic bladder of chronic spinal rabbits. MATERIAL AND METHODS: Detrusor muscle strips were obtained from normal rabbits and chronic spinal rabbits with detrusor hyperreflexia and detrusor sphincter dyssynergia (DSD). Muscle strips were mounted in an organ bath, and transmural nerve electrical field stimulation (EFS: supamaximal voltage, 0.5 msec. duration, 10 second trains) was performed. The responses to EFS and agonists were determined by recording the isometric tension of muscle strips. RESULTS: Both normal and pathologic detrusor strips contracted in a frequency dependent fashion in response to transmural electrical nerve stimulation. At each frequency, atropine reduced the nerve-mediated contraction in a dose-dependent fashion and left an atropine-resistant response at a concentration of 1 microM. The atropine-resistant contraction was abolished by desensitization of P2X-purinoceptors with repeated exposure to alpha, beta-methylene ATP (10 microM). The atropine sensitive (cholinergic) and resistant (purinergic) contractions increased with an increase in frequency and reached maximum at 20 Hz. The relative contribution of cholinergic and purinergic transmission to the nerve-mediated contraction was determined at this frequency. In normal detrusor, the cholinergic and purinergic components were approximately 40% and 60%. In pathologic detrusor, the cholinergic component increased to 75% whereas the purinergic component decreased to 25%. Exogenously administered acetylcholine and ATP produced dose-dependent contractions of detrusor strips. The concentration-response curves for each agonist did not show significant differences between normal and pathologic detrusor. CONCLUSION: These results suggest that neurotransmission is shifted to a cholinergic dominance in pathologic rabbit bladder affected by detrusor hyperreflexia and DSD.

Acetylcholine↗
PubMed1996

[Burned-out tumor and carcinoma-in-situ of the testis mimicking an extragonadal germ cell tumor: a case report].

Multiple tumors of mediastinum, retroperitoneum and lung were detected in a 40-year-old man presented with lumbago and lower abdominal pain. As biopsy specimen taken from the cervical lymph node suggested germ-cell tumor and his testes were normally palpable, the initial diagnosis was an extragonadal germ-cell tumor. However, since ultrasonography of his left testis showed a small high echoic lesion (5 mm) assumed to be a burned-out tumor, orchiectomy was performed. Histological findings confirmed scar tissue as burned-out tumor and also revealed some malignant cells lining the seminiferous tubules that were thought to be the carcinoma-in-situ of the testis. After chemotherapy of etoposide and cisplatinum he achieved a partial response which has been maintained for 7 months. Examinations for burned-out tumor or carcinoma-in-situ of the testis should be made for the patients with an extragonadal germ cell tumor who have normally palpable testes.

Adult↗
PubMed1995

[A case of adult Wilms' tumor with vena caval involvement].

The patient was a 35-year-old female with the chief complaint of macrohematuria. Computerized tomographic (CT) scan, ultrasonography and magnetic resonance imaging (MRI) revealed the presence of a large and inhomogeneous mass in the left kidney, and a tumor thrombus growing in the inferior vena cava. Angiography also showed a hypervascular tumor in the left kidney. The chest X-ray and CT scan demonstrated multiple metastatic lesions in the bilateral lungs. Radical nephrectomy and thrombectomy was performed under the diagnosis of left renal tumor with its invasion of inferior vena cava. Pathological findings revealed that this tumor was nephroblastoma, and its type was clear cell sarcoma of the kidney (CCSK). The patient received chemotherapy according to National Wilms' Tumor Study (NWTS) IV chemotherapeutic drug regimen. In general, CCSK is known to have poor prognosis. However, doxorubicin has been reported to have a relatively good antitumor effect for CCSK. However, in this case, the evaluation after the first course of chemotherapy was progressive disease, because some new lesions appeared, although most old pulmonary metastatic lesions were reduced.

Adult↗
PubMed1994

Potentiation of antitumor effect of bleomycin by local electric pulses in mouse bladder tumor.

C3H mice bearing subcutaneously transplanted mouse bladder carcinoma (MBT-2) were treated with intramuscular injection of bleomycin followed by local delivery of electric pulses at the tumor site. The tumors markedly reduced and even disappeared for several days after this treatment. Neither electric pulses nor bleomycin administration alone showed a significant inhibitory effect on the tumor growth. Thus, it is demonstrated that in mouse bladder tumor the antitumor effect of bleomycin can be considerably potentiated by local electric pulses.

Animals↗
PubMed1994

[A case of adult mature nephroblastic tumor].

A 22-year-old woman had a well differentiated nephroblastic tumor. The tumor was composed of mesenchymal elements with mature tubules and occasionally smooth muscle elements. None of the cellular elements showed any feature indicative of malignancy. Histologically this was similar to congenital mesoblastic nephroma, but the tumor showed an evidence of a uniform expansile growth. It was considered to be a form of mature nephroblastoma.

Adult↗
PubMed1993

Calcium control of actin-myosin-based contraction in Triton-treated murine bladder tumor cells.

Using mouse bladder tumor cells (MBT-2 cells) and epithelial cells, the present study evaluated the functional characteristics of the actomyosin system in bladder cancer cells. An immunofluorescence study demonstrated the presence of contractile proteins (actin and myosin) in MBT-2 cells as well as bladder epithelial cells. Triton-treated MBT-2 cells and epithelial cells showed a Ca(2+)-dependent contraction. This was inhibited by N-ethylmaleimide-modified myosin subfragment 1 (NEM-S1), demonstrating that the interaction between actin and myosin is responsible for the contraction of Triton-treated cells. The extent of Ca(2+)-dependent contraction was much greater in MBT-2 cells than in epithelial cells. These results suggest that MBT-2 cells possess a locomotive apparatus consisting of actin and myosin, and that Ca2+ can activate this actomyosin system, leading to the contraction or active locomotory movement of tumor cells.

Actins↗
PubMed1993

Chemical structures of two subunits, A-subunit and B-subunit, of galactose-specific isolectins from Erythrina variegata seeds.

We previously isolated galactose-specific isolectins, EVLI, EVLII, and EVLIII, from the Erythrina variegata seeds [J. Chromatogr. 597, 207-211 (1992)]. The amino acid sequences of the two subunits, A- and B-subunits, of which the isolectins are composed, were determined. A comparison of the amino acid sequences of tryptic peptides from the two subunits revealed seven amino acid substitutions. Among them, Asn46, to which the oligosaccharide chain is linked in the A-subunit, is replaced by Asp46 in the B-subunit, causing the B-subunit to lack one glycosylation site. The N-linked oligosaccharides of these subunits were also analyzed. The N-linked oligosaccharides were first liberated by hydrazinolysis. After N-acetylation, the reducing ends of the oligosaccharides were coupled with 2-aminopyridine, and then the pyridylamino (PA-) derivatives were purified by gel filtration and HPLC on an ODS-silica column. One major sugar chain, accounting for more than 98% of the total, was purified from both species. The structure of this major sugar chain was established to be Man alpha 6(Man alpha 3)(Xyl beta 2)Man beta 4GlcNAc beta 4(Fuc alpha 3)GlcNAc. This finding that there is no structural difference of the sugar chains linked to the two subunits of E. variegata lectins, together with the results of amino acid sequence comparisons, indicates that the difference in molecular mass of these two subunits results almost wholly from the difference in the number of oligosaccharides linked to them.

Amino Acid Sequence↗
PubMed1993

Cloning of the genes that control formation of the fimbrial colonization factor antigen III (CFA/III) from an enterotoxigenic Escherichia coli.

Enterotoxigenic Escherichia coli strain 260-1 produces colonization factor antigen III and heat-labile enterotoxin. A 55-kb plasmid controlling the expression of the colonization factor antigen was isolated from this strain after it was labeled with ampicillin resistance transposon, Tn3. When this plasmid was introduced into E. coli K-12 strains, it induced the formation of pili that were morphologically and immunologically identical to those on the surface of 260-1 cells, as examined by electron microscopic observation and with the specific antiserum. The physical map of the plasmid was constructed, and the 17.4-kb region was found to be responsible for the expression of the pili.

Agglutination Tests↗
PubMed1993

Seasonal changes of parathyroid hormone in chronic hemodialysis patients.

We investigated various factors related to secondary hyperparathyroidism among hemodialysis patients. Subjects were 26 patients (20 men and 6 women) ranging in age from 24 to 75, treated at an ordinary hemodialysis center throughout the year 1991. The serum inorganic phosphate level and serum intact PTH level varied greatly from 2.5 to 12.5 mg/dl and from 10 to 1,102 pg/ml (normal range, 10-60 pg/ml), respectively. All patients were classified according to the serum intact PTH level into two groups: those with less than 120 pg/ml (Group I) and those with 120 pg/ml or more (Group II). The patients in Group I responded well to hemodialysis and drug therapy, but those in Group II were likely to have secondary hyperparathyroidism. In all patients in Group II, the PTH level increased markedly in the summer. This may be attributed to insufficient ingestion of calcium, vitamins, and other nutrients due to loss of appetite.

Adult↗
PubMed1993

[A radiological study of the hip joint in cerebral palsy].

In cerebral palsy (CP), abnormal posture, contracture of the hip and dislocation occur during a long period of the course. In order to clarify the factors of tendency to dislocation, radiological survey was undertaken for the patients of CP. These data were analyzed from the respects of weight bearing, position of leg and developed deformity at the neck of the femur. One hundred seventy eight hips of 90 patients with an average of 26 years of age and 64 hips of normal individual as a control. Kai's method was used for measuring angles of tilting at neck and anteversion. The incidence of dislocations of the hip joints was more frequent in patients who were incapable of weight bearing than in patients who were capable of weight bearing (p < 0.01). However, there was no difference between spastic type and athetotic type of CP. In patients who were incapable of weight bearing inclination (the neck-shaft angle), anteversion of the femoral neck to the shaft showed larger than in patients who were capable of weight bearing (p < 0.01). Anteversion of patients who were capable of weight bearing of CP was larger than that of the normal control (p < 0.01), but extent of inclination was the same. From these findings the present investigator has concluded that femoral neck becomes valgus with an increased anteversion in longstanding CP patients who are especially unable to stand or walk. Furthermore, such hip joints are found to dislocate easily if adducted.

Adolescent↗
PubMed1992

Isolation and characterization of isolectins from Erythrina variegata seeds.

Three isolectins were isolated from seeds of Erythrina variegata (Linn.) var. Orientalis by ion-exchange chromatography, followed by affinity chromatography on lactose-Sepharose 4B and acid-treated Sepharose 4B columns. The purified isolectins (EVLI, EVLII and EVLIII) are all specific for galactopyranosides and N-acetylgalactosamine, and their affinities for simple sugars are EVLIII greater than EVLII greater than EVLI. EVLI and EVLIII are homodimers made up of an A-subunit of molecular mass 36,000 and a B-subunit of molecular mass 33,000, whereas EVLII is a heterodimer composed of the A- and B-subunits. Upon treatment with trifluoromethansulphonic acid, the molecular masses of both subunits decreased to 31,000. Rechromatography of EVLII on the acid-treated Sepharose 4B column again produced the homodimeric lectins (EVLI and EVLIII). It is suggested that the constituent subunits of Erythrina variegata isolectins are eschangeable with each other in vitro.

Amino Acids↗
PubMed1992

Prototype of a reflux-preventing ureteral stent and its clinical use.

We have experimentally produced a ureteral stent which prevents vesicorenal reflux. This stent has a thin silicon sleeve at its distal end (intravesical portion). In a model experiment the sleeve demonstrated an excellent capability to prevent reflux. The sleeve allowed flow of fluid with minimal pressure rise. A patient with bilateral ureteral obstruction was managed with endoscopic insertion of a sleeved stent in the right ureter and a usual pigtail stent in left ureter. During cystography vesicorenal reflux was not observed on the right side while reflux occurred on the left side. Excretory urography forty days after stent placement demonstrated recovery of renal function and maintenance of drainage in both renal units. Thus, the drainage characteristic of this stent appears to be approximately the same as that of usual stent.

Drainage↗
PubMed1992

[Clinical results of prophylactic intravesical chemotherapy on superficial bladder cancer using the dye exclusion assay].

A chemosensitivity test was carried out on superficial bladder cancer using the dye exclusion assay for the purpose of screening chemosensitive drugs for prophylactic intravesical chemotherapy. Bladder cancer cells of each patients were incubated, in vitro, in the presence of adriamycin, (2"R)-4'-0-tetrahydropyranyladriamycin, mitomycin C, pepleomycin and 4'-epi-adriamycin (500 micrograms/ml) at 5%, CO2, 37 degrees C for 2 hours. The cytotoxic effect of the drugs was evaluated by the ratio of stained cells by trypan-blue. The most effective drug was instilled postoperatively into the bladder 3 times for the first week, and every 2 weeks during the following 14 weeks. In 18 patients followed more than 4 months the prophylactic effect was evaluated. Fifteen of the 18 patients completed the protocol, but the remaining 3 patients failed to complete to the instillation because of severe irritability of the bladder. Tumor recurrence was demonstrated in two patients. Non-recurrence rates of tumors at 12 and 24 months were 93.8% and 82.0%, respectively. These results suggested that this rapid and handy assay was useful for the purpose of screening chemosensitive drugs for the intravesical chemotherapy.

Administration, Intravesical↗