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Biomedical subjects

S Yamazaki

Publications and source records attributed to S Yamazaki.

At least 145 records · Page 8Linked to original sources
PubMed1999

Contractile responses to alpha1-adrenoceptor agonists in isolated human male and female urethra.

OBJECTIVE: To investigate the contractile responses mediated through alpha1-adrenoceptors in human urethra and to evaluate the effectiveness of NS-49 [(R)-(-)-3'-(2-amino-1-hydroxyethyl)-4'-fluoromethanesulphonanilide++ + hydrochloride], a novel alpha1-adrenoceptor agonist, against contraction of the human urethra. MATERIALS AND METHODS: The contractile responses were assessed in 10 male prostatic urethrae and six female urethrae. Antagonism was evaluated in the urethra using phenylephrine, a nonselective alpha1-adrenoceptor agonist, cumulatively applied > 20 min after applying 0.1 micromol/L prazosin or 0.1 micromol/L 5-methylurapidil, a selective alpha1A-adrenoceptor antagonist. Agonism was determined in both male and female urethrae to obtain the concentration-response curve for the agonist. RESULTS: Phenylephrine caused both male and female urethrae to contract, and showed high potency and efficacy. Prazosin antagonized these contractions with low affinity (apparent pKB of 8.30 in male urethrae). 5-Methylurapidil, also antagonized the contractions with low affinity (apparent pKB of 7.88 in male urethrae). Noradrenaline and phenylephrine caused both male and female urethrae to contract, with high potency and efficacy. A novel and selective alpha1A-and alpha1L-adrenoceptor agonist, NS-49, induced contractile responses with high potency and moderate efficacy, whereas methoxamine induced contractions with low potency and moderate efficacy. Norephedrine was a very weak contractile agonist. CONCLUSION: In the human urethra, phenylephrine-induced contractions were mediated through alpha1L-adrenoceptors and not through alpha1A-adrenoceptors. Contractions of the human urethra induced by NS-49 were also mediated mainly through alpha1L-adrenoceptors, with high potency and moderate efficacy. NS-49 may therefore be useful for the treatment of urinary stress incontinence, with minimal side-effects because it has subtype selectivity.

Adrenergic alpha-Agonists↗
PubMed1999

Relationship between immunoclinical status and prevalence of viral sexually transmitted diseases among human immunodeficiency virus-1 seropositive patients in Ghana.

In view of the strong association between the acquired immunodeficiency syndrome (AIDS) and sexually transmitted diseases (STDs), we screened 182 human immunodeficiency virus (HIV)-1 infected patients over a 15-month period for serological markers to previously encountered or current STDs, most of viral etiology. The relationship between their immunological and clinical status and the prevalence of STDs was assessed and compared with that of 88 HIV-seronegative patients. Hepatitis B virus and Treponema pallidum were the most frequently occurring pathogens in both HIV-1-infected and HIV-seronegative patients. Hepatitis C virus (HCV) infection was also observed in both groups, but no HIV-seronegative patient was infected with human T-lymphotropic virus type 1 (HTLV-1). The Centers for Disease Control clinical staging of A1 through C3, representing asymptomatic to severe AIDS conditions, was observed in HIV-1 patients with or without STDs. A mean CD4 count of 288 cells per microliter (95% CI of 237-340 cells per microliter) in HIV-1 patients was significantly lower (P < 0.05) than that in HIV-seronegative individuals with 1019 cells per microliter (95% CI of 924-1115 cells per microliter), irrespective of whether subjects in either group had previous or current STDs. The mean CD4 count of patients with a single infection from HIV-1 was not significantly different (P = 0.36) from that of HIV-1 patients with multiple infections. HIV-1 infection alone appears to be responsible for the marked immunodeficiency status of seropositive patients observed in this study.

AIDS-Related Opportunistic Infections↗
PubMed1999

Anaerobic purification and characterization of nitrous oxide reductase from Rhodobacter sphaeroides f. sp. denitrificans IL106.

The nitrous oxide reductase from the photodenitrifier, Rhodobacter sphaeroides f. sp. denitrificans IL106, has been purified under anaerobic conditions. The specific activity of the enzyme was 78 micromol nitrous oxide reduced per min per mg protein, which was approximately 80% higher than that of the aerobic form. The enzyme purified anaerobically retained most of its activity after aerobic storage at 4 degrees C for 2 months without any additives. Visible absorption spectra of the Rhodobacter nitrous oxide reductase resembled those of the enzymes from other origins. The enzyme retained its activity after reduction with sodium dithionite, and the enzyme activity could be determined using dithionite-reduced benzyl viologen. Turnover-dependent inactivation of the enzyme was suppressed by complete removal of oxygen from the reaction mixture, and promoted by zinc ions.

Chromatography, Gel↗
PubMed1999

A case of prurigo and lichenified plaques successfully treated with proton pump inhibitor.

A case of prurigo and lichenified plaques successfully treated with proton pump inhibitor is presented. She presented with pruritic eruptions, which showed marked lichenification and prurigo nodules, on her trunk and extremities. She had been treated with steroid ointment and H1-histamine receptor antagonist without success. Laboratory examinations revealed increased eosiophils and elevated lactate dehydrogenase. The skin biopsy specimen showed moderate acanthosis with spongiosis and lymphocytic and eosinophilic infiltration into the upper dermis. Because of vomiting and epigastralgia, endoscopical examination was performed, and an ulcer was found at the angle of her ventricle. A biopsy specimen disclosed a benign gastric mucosa with moderate inflammation within the lamina propria, and organisms consistent with Helicobacter pylori. Treatment for gastric ulcer with proton pump inhibitor (omeprazole) and aluminium hydroxide gel improved her eruptions and her pruritus resolved. She was discharged with complete cure of her eruption and ventricular ulcer. Our case indicates that gastric lesions induced by Helicobacter pylori infection may play an important role in dermatological diseases. Proton pump inhibitors including omeprazole are one of the choices for the treatment of some dermatological diseases including prurigo and lichenified plaques.

Aged↗
PubMed1999

A case of pediatric Behçet's disease with intestinal involvement.

We report a 6-year-old girl with recurrent oral aphthae, genital and perianal ulcers, and folliculitis-like erythema followed by intestinal symptoms. No ocular lesions were found. Her ailment was diagnosed as incomplete Behçet's disease with intestinal involvement. According to the literature, pediatric Behçet's disease is characterized by a low incidence of ocular lesions and a high incidence of intestinal involvement, as exhibited in this case. As intestinal lesions in pediatric Behçet's disease are often life-threatening, a barium enema must be given to exclude the possibility of intestinal involvement when pediatric patients with Behçet's disease complain of abdominal pain.

Behcet Syndrome↗
PubMed1999

Treatment of reticular erythematous mucinosis with a large dose of ultraviolet B radiation and steroid impregnated tape.

To date, there are no successful treatments for reticular erythematous mucinosis (REM) other than antimalarial drugs such as chloroquine; these have many adverse side effects and are prohibited for use in Japan. We report a case of REM improved by a large dose of ultraviolet B (UVB) radiation and a steroid impregnated tape. The large dose of UVB radiation improved the erythema after 5 weeks. Application of steroid impregnated tape to a lesion where a large dose of UVB had been given produced an additive clinical effect. UVB radiation and steroid impregnated tape are considered to be effective treatments for REM.

Combined Modality Therapy↗
PubMed1999

No evidence for extraocular photoreceptors in the circadian system of the Syrian hamster.

Campbell and Murphy reported recently that 3 h of bright light (13,000 lux) exposure to the area behind the knee caused phase shifts of the circadian rhythms of both body temperature and saliva melatonin in humans. The authors tested the hypothesis that extraocular photoreception is also involved in the circadian system of the Syrian hamster. Hamsters were bilaterally enucleated (eyes removed), and their backs were shaved. Hamsters with stable free-running rhythms in constant darkness were exposed to direct sunlight for 1 or 3 hours during their subjective night. Intact (control) animals showed phase shifts as expected, but the locomotor activity of enucleated animals was unaffected by the exposure to sunlight. The authors also measured the pineal melatonin content after exposure to sunlight. Pineal melatonin content in intact animals declined markedly as expected, but no decline was observed in the enucleated hamsters. The authors conclude that extraocular phototransduction is not capable of shifting the phase of the hamster's locomotor activity rhythm or of suppressing pineal melatonin synthesis.

Animals↗
PubMed1999

[Superior vena cava reconstruction combined with resection of mediastinal-pulmonary malignant tumors].

From 1988 to 1997, we experienced 5 cases of the superior vena cava (SVC) replacement with expanded polytetrafluoroethylene (ePTFE) grafts combined with resection of mediastinal or pulmonary malignant tumors. Two patients had lung cancer and three had invasive thymoma. Resection and reconstruction of the superior vena cava (SVC) were performed by application of a bypass graft between the innominate vein and the right atrium in two cases and a temporary bypass using a heparin-coated tube in three cases. Except in one patient who died of acute respiratory failure, no complication or occlusive symptom were observed postoperatively. Two patients remain healthy for 5 years 4 months and 2 years 7 months after operation. Three died 9 years, 5 months, and 110 days after operation respectively. In conclusion, ePTFE graft replacement or patch angioplasty of the SVC should be part of planning and execution of radical excision with curative intent of mediastinal or pulmonary malignant tumors.

Adult↗
PubMed1999

[Combined resection of the descending aorta under a simple temporary bypass for advanced lung cancer invading the aorta].

Three patients with advanced lung cancer invading the descending aorta underwent concomitant resection under a simple temporary bypass using thin-wall metallic cannulas. In each case, invasion to the descending aorta was suspected by CT and MRI. In case 1, resection of adventitia of the aorta was performed under a temporary bypass between the left subculavian artery and the descending aorta. In case 2 and 3, tubular resection and reconstruction of the aorta were carried out under a temporary bypass between proximal site of descending aorta from involved level and distal site. Complete resections of tumors were performed in all cases. During and after operation, vital signs were stable and no ischemic disorder of lower limbs and abdominal organs were observed. Case 1 died 7 months postoperatively because of recurrence in small intestine. Case 2 and 3 are alive at present, 21 and 5 months postoperatively, respectively. This procedure has advantages of safety, simplicity, and low invasiveness, in the cases the left subcuravian artery or the descending aorta is available for proximal site of the temporary bypass.

Aorta, Thoracic↗
PubMed1999

[Treatments for post-pneumonectomy pyothorax without broncho-pleural fistula: irrigation of the post-pneumonectomy space].

Between January 1986 and December 1997 pneumonectomy was performed in 58 patients. Of the 58 patients, four had pyothorax without broncho-pleural fistula. Four patients underwent chest tube drainage and irrigation of the post-pneumonectomy space, and one of which died of lung cancer during treatment for pyothorax. Two had no evidence of recurrent infection, and one had a chest wall fistula after about one year and a fistulectomy was performed. These observations suggest that draining and irrigating of the post-pneumonectomy space are effective and non-invasive methods for treating post-pneumonectomy pyothorax without broncho-pleural fistula. However we were not able to investigate specific methods, fluid types, or irrigation time frames.

Empyema, Pleural↗
PubMed1999

New alpha1-adrenoceptor antagonist, JTH-601, shows more than 10 times higher affinity for human prostates than arteries.

PURPOSE: We compared the affinities of a new alpha1-adrenoceptor (AR) antagonist, JTH-601 with those of several alpha1-AR antagonists in human prostates and arteries. RESULTS: In the functional study, noradrenaline produced concentration-dependent contractions in human prostates and mesenteric arteries. The pA2/pKB values for the antagonists in the human prostate were 9.78 for tamsulosin, 8.84 for JTH-601, 8.39 for WB4101, 8.23 for prazosin, 8.12 for JTH-601-G1 (a main metabolite of JTH-601 in human) and 6.57 for BMY7378. Compared these affinities with those in the mesenteric artery, only JTH-601 and JTH-601-G1 exhibited unique uroselectivity, showing 10- to 20-fold higher affinity for the human prostate than for mesenteric artery. The affinity profile of these antagonists suggested that the noradrenaline-induced contractions in the human prostate and the mesenteric artery were mediated by the alpha1L-AR and alpha1B-AR, respectively. In the competition binding study, the pharmacological profiles of the antagonists against [3H]-prazosin were examined in the human prostate and aorta. The resulting pKi values for JTH-601 and JTH-601-G1 were also approximately 10- to 20-fold higher for the human prostate than for the human aorta. CONCLUSION: These results have suggested that JTH-601 and JTH-601-G1 are unique uroselective alpha1-AR antagonists that show higher affinity for the human prostate than for the human arteries.

Adrenergic alpha-Antagonists↗
PubMed1999

Increased renal retention of 99mTc-methylene diphosphonate after nephron-sparing surgery.

UNLABELLED: Nephron-sparing surgery has become established as an effective treatment for localized renal cell carcinoma when preservation of renal function is necessary. The surgery usually requires temporary renal artery occlusion and may induce ischemic renal damage. In this study, we retrospectively evaluated renal activity on bone scintigraphy after nephron-sparing surgery. METHODS: Eleven patients who underwent nephron-sparing surgery for renal cell carcinoma and had a normal contralateral kidney were studied. A total of 12 bone scintigraphy images with 99mTc-labeled methylene diphosphonate were obtained within 1 y after surgery in these patients to assess skeletal metastasis. Activity in the spared renal parenchyma was compared visually with that in the contralateral normal kidney. RESULTS: The tumor was successfully resected in every patient, and no clinically significant complications occurred. Activity in the spared renal parenchyma was elevated in six of seven examinations performed within 21 d after surgery. In three examinations, the increase in renal activity was heterogeneous, being relatively prominent near the surgical margin. Increased renal activity was not observed on five examinations performed 3 mo or more after surgery. CONCLUSION: Renal retention of bone-seeking agents is elevated in the early period after nephron-sparing surgery, probably as a result of ischemic insult during the surgical procedure. Bone scintigraphy may aid in evaluating the presence and degree of ischemic damage of the spared renal parenchyma.

Adult↗
PubMed1999

[Antidiuretic hormone in severe cases of atopic dermatitis].

32 out of 83 in patients with atopic dermatitis showed a decrease of urine excretion during acute exacerbation and elevated levels of antidiuretic hormone (ADH 23 of 29 cases), renin (18 of 32 cases), angiotensin (22 of 29 cases) and aldosterone (16 of 37 cases). Six cases with high ADH showed severe pitting edema of lower legs with hypoalbuminemia. ADH, volume of urine and edema were improved when their skin symptoms subsided. There was no statistically significant relationship between the dose of steroid ointment and ADH. Also there was no correlation between low 17-OHCS or 17-KS and high ADH or renin.

Adult↗
PubMed1999

[Characterization of hepatic bile mucus glycoprotein in hepatolithiasis].

To study the characterization of hepatic bile mucus glycoprotein in hepatolithiasis cases, we isolated glycoprotein from the bile of patients with intrahepatic gallstones by gel filtration and ultracentrifugation. The carbohydrate chains of mucus glycoprotein were released by hydrazinolysis. The properties of the hepatolithiasis carbohydrate chains were compared with those of a control group. The mucus glycoprotein concentration in bile in hepatolithiasis patients (299.9 micrograms/ml) was higher than that in the controls (28.0 micrograms/ml). Both groups had no evident changes in molecular weight or amino acid composition. The quantities of N-Galactosamine and sulfate in the hepatolithiasis group were larger than in those of the control group. Carbohydrate chain lengths in the hepatolithiasis group were shorter than those in the control group. This phenomenon suggests that mucus glycoprotein of the bile in hepatolithiasis patients has a different metabolism and biological function from that of normal bile.

Amino Acids↗
PubMed1999

Seroepidemiology of human parvovirus B19 in Taiwan.

In order to determine the prevalence and risk factors of human parvovirus B19 (B19) infection in Taiwan, a seroepidemiological study was carried out in 19 townships. Serum samples were collected from 862 healthy residents, who were selected by stratified random sampling from various study areas. They were chosen from four different ethnic groups including aborigines, Fukien Taiwanese, Hakka Taiwanese, and mainland Chinese. Serum samples were screened for B19 IgG antibody by indirect antibody capture enzyme-linked immunosorbent assay (ELISA) and B19 IgM by IgM antibody capture (MAC)-ELISA, respectively. The overall prevalence of anti-B19 IgG and anti-B19 IgM was 32.8% and 0.35%, respectively. The anti-B19 seropositive rate in females was significantly higher than that of males (36.4% vs. 29.4%, P < .001). The age-sex-adjusted seropositive rate in urban townships (39.9%) was higher than that in aboriginal townships (30.5%, P < .001). The seropositive rate increased significantly with age showing a dose-response relationship (P=0.0001 based on a trend test). Blood transfusion was found to be associated with an increased seropositive rate showing a multivariate-adjusted odds ratios of 1.6.

Adolescent↗
PubMed1998

Rhythmic properties of the hamster suprachiasmatic nucleus in vivo.

We recorded multiple unit neural activity [multiunit activity (MUA)] from inside and outside of the suprachiasmatic nucleus (SCN) in freely moving male golden hamsters housed in running-wheel cages under both light/dark cycles and constant darkness. The circadian period of MUA in the SCN matched the period of locomotor activity; it was approximately 24 hr in wild-type and 20 hr in homozygous tau mutant hamsters. The peak of MUA in the SCN always occurred in the middle of the day or, in constant darkness, the subjective day. There were circadian rhythms of MUA outside of the SCN in the ventrolateral thalamic nucleus, the caudate putamen, the accumbens nucleus, the medial septum, the lateral septum, the ventromedial hypothalamic nucleus, the medial preoptic region, and the stria medullaris. These rhythms were out-of-phase with the electrical rhythm in the SCN but in-phase with the rhythm of locomotor activity, peaking during the night or subjective night. In addition to circadian rhythms, there were significant ultradian rhythms present; one, with a period of approximately 80 min, was in antiphase between the SCN and other brain areas, and another, with a period of approximately 14 min, was in-phase between the SCN and other brain areas. The periods of these ultradian rhythms were not significantly different in wild-type and tau mutant hamsters. Of particular interest was the unique phase relationship between the MUA of the bed nucleus of the stria terminalis (BNST) and the SCN; in these two areas both circadian and ultradian components were always in-phase. This suggests that the BNST is strongly coupled to the SCN and may be one of its major output pathways. In addition to circadian and ultradian rhythms of MUA, neural activity both within and outside the SCN was acutely affected by locomotor activity. Whenever a hamster ran on its wheel, MUA in the SCN and the BNST was suppressed, and MUA in other areas was enhanced.

Activity Cycles↗