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Y Sakai

Publications and source records attributed to Y Sakai.

At least 127 records · Page 7Linked to original sources
PubMed2001

[Laparoscopic radical prostatectomy: initial 17 case report].

PURPOSE: We report our early experience of laparoscopic radical prostatectomy for clinically localized prostatic cancer. MATERIAL AND METHOD: Between April and December 2000, 17 patients with clinical stage T1c to T2b prostatic cancer underwent laparoscopic radical prostatectomy. The median age was 70.9 year old, the median preoperative PSA and the median Gleason score of biopsy specimens was 7.1 ng/ml, 6, respectively. We followed the operation technique from the "Montsouris technique". Briefly, we used five trocars (two 10-mm and three 5-mm trocars) and the operation was performed transperitoneally. Pelvic lymph node dissection was performed in only one patient (case 3). Urethrovesical anastomosis was performed with 6 to 9 interrupted 3-0 absorbable sutures. RESULTS: No conversion to open surgery or reoperation was required in all cases. Median operation time was 450 minutes (range 290 to 750) and median intraoperative bleeding (including urine) was 600 ml (range 100 to 3,135). Only one case (case 3) needed homologous blood transfusion. Median postoperative Foley catheterization period was 9 days (range 5 to 19). Intraoperative complications related to operation procedure were one rectal injury and three vesical injuries, which were treated by absorbable suturing laparoscopically. Major complication was one complete A-V block (case 3) who was required a transient discontinuance of the procedure. Surgical margins were negative in 13 cases. Postoperative pathological evaluation was one pT0, five pT2a, seven pT2b and four pT3a. PSA value decreased less than 0.2 ng/ml after surgery in all patients. Although six months have passed after the surgery in only 4 patients, all of them were fully continent. CONCLUSION: Although the operation time is still longer than that of conventional open procedures, intraoperative magnified vision allows a more precise and safer dissection, especially for apical dissection. We believe that operative time will decrease with more experience. These results show that laparoscopic radical prostatectomy can be an acceptable treatment option for localized prostatic cancer.

Aged↗
PubMed2001

Effects of organic solvents on the activities of cytochrome P450 isoforms, UDP-dependent glucuronyl transferase, and phenol sulfotransferase in human hepatocytes.

We studied the effects of acetonitrile, dimethyl sulfoxide (DMSO), and methanol (MeOH) in human hepatocytes on cytochrome P450 (CYP) and phase II conjugation activities: phenacetin O-deethylation (CYP1A2), coumarin 7-hydroxylation (CYP2A6), tolbutamide 4-hydroxylation (CYP2C9), S-mephenytoin 4'-hydroxylation (CYP2C19), dextromethorphan O-demethylation (CYP2D6), chlorzoxazone 6-hydroxylation (CYP2E1), testosterone 6beta-hydroxylation (CYP3A4), and umbelliferone glucuronidation and sulfation. The solvents were evaluated at concentrations (v/v) of 0.1, 1, and 2%. Previously cryopreserved human hepatocytes pooled from multiple donors were used as suspension cultures in this study. DMSO was found to inhibit CYP2C9 and CYP2C19, CYP2E1, and CYP3A4 in a concentration-dependent manner. At 2% DMSO, the activities for the four isoforms were approximately 40% (CYP2C9), 23% (CYP2C19), and 11% (CYP2E1) of that observed for 0.1% acetonitrile and 45% (CYP3A4) of that observed for 1% acetonitrile. No apparent inhibitory effects were observed for the other activities evaluated. Methanol was found to inhibit CYP2C9 and CYP2E1 activities, but to a lesser extent than DMSO. Acetonitrile had no apparent effects on any of the on any of the activities evaluated. These findings should be considered when choosing an organic solvent for metabolism studies with human hepatocytes.

Acetonitriles↗
PubMed2001

Efficacy of nonwoven fabric bioreactor immobilized with porcine hepatocytes for ex vivo xenogeneic perfusion treatment of liver failure in dogs.

We have developed a new bioartificial liver bioreactor filled with porcine hepatocytes immobilized on polyester nonwoven fabric (NWF). In this study, we investigated the efficacy of our hybrid bioartificial liver system incorporating the NWF bioreactors and an immunoglobulin adsorbent column for perfusion treatment in a canine liver failure model. Xenogeneic perfusion treatment for operative canine liver failure models were performed for 3 h, and survival time, intracranial pressure, and blood and cerebrospinal fluid data were documented. Treatment was carried out without obstruction by immunological rejection when immunoglobulin adsorbent columns were used with the NWF bioreactors in combination. Dogs treated with this system exhibited a restricted increase of intracranial pressure and significant compensatory effects on blood and cerebrospinal amino acid imbalances as shown by a significant improvement of Fischer's ratio. On the other hand, relatively low capacity for ammonia elimination was shown as compared with homologous direct hemoperfusion.

Animals↗
PubMed2001

The apolipoprotein E genotype influences the risk for vasospastic angina.

It has been suggested that people with the epsilon4 allele of the apolipoprotein E (apoE) polymorphism and the deletion (D) allele of the insertion (I/D) polymorphism of angiotensin-converting enzymes, are at a greater risk for coronary artery disease. However, only a few studies have examined the relationships between vasospastic angina (VSA) and genotype, especially with the apoE polymorphism. In the present study, 76 patients with VSA without significant fixed coronary artery stenosis, 149 patients with ischemic heart disease (IHD) who had 75% or more luminal diameter narrowing and 213 healthy subjects were enrolled. The odds ratio for VSA of the epsilon4 allele carriers relative to the epsilon3/3 allele subjects compared with subjects with IHD and control subjects combined was 0.44 (95% CI 0.21 to 0.93, P=0.021), and that compared with control subjects alone was 0.36 (95% CI 0.17 to 0.78, P=0.005), implying that the presence of the epsilon4 allele indicates resistance to the development of VSA. In contrast, people with the epsilon2 allele showed a tendency to develop VSA more frequently than did patients with IHD (P=0.009), although the frequency of the epsilon2 allele did not differ between patients with VSA and control subjects. On the other hand, no recessive and dominant effects of the D alleles on VSA were found. These findings suggest that the risk of the occurrence of VSA may be reduced by the epsilon4 allele and increased by the epsilon2 allele. The ApoE polymorphism may be associated with IHD and VSA, probably due to the modulation of lipid metabolism.

Adult↗
PubMed2001

Rebamipide inhibits ceramide-induced interleukin-8 production in Kato III human gastric cancer cells.

Helicobacter pylori adheres to gastric epithelial cells and stimulates interleukin-8 production. Ceramide, a lipid second messenger, has become known as an important mediator of some actions of several cytokines. We have recently reported that H. pylori-dependent ceramide production may activate nuclear factor-kappaB and mediate interleukin-8 expression in human gastric cancer cell lines. In this study, we evaluated the effect of rebamipide, an antigastritis and antiulcer agent, on H. pylori-dependent ceramide production and subsequent interleukin-8 expression in Kato III cells. Rebamipide inhibited ceramide-induced interleukin-8 expression in a dose-dependent manner. Rebamipide decreased the ceramide-induced increase of the interleukin-8 mRNA level as assessed by Northern blotting. Rebamipide suppressed interleukin-8 gene transcription and nuclear factor-kappaB-dependent transcriptional activity as assessed by luciferase assay. Rebamipide inhibited the ceramide-induced degradation of IkappaB-alpha (a major cytoplasmic inhibitor of nuclear factor-kappaB), further supporting that rebamipide inhibits the activation of nuclear factor-kappaB. Rebamipide also inhibited the ceramide-dependent activation of mitogen-activated protein kinases. Furthermore, rebamipide significantly attenuated the H. pylori-dependent increase in the intracellular ceramide level. These results suggest a novel mechanism by which rebamipide may protect against the mucosal inflammation associated with H. pylori infection.

Alanine↗
PubMed2001

Formation of human fibroblast aggregates (spheroids) by rotational culture.

In the current study, we attempted to form aggregates of fibroblasts by rotationally shaking, declining fibroblast-material interactions, and augmenting cell-cell interactions. In addition, to promote cell-cell interactions, the medium was supplemented with insulin, dexamethasone, and basic fibroblast growth. Under such improved culture conditions, normal neonatal human dermal fibroblasts formed spheroidal aggregates within 1 day of rotation on a rotational shaker. The aggregates that formed had irregular shapes and were composed from only several cells after 12 h. However, they became nearly spheroidal after 24 h of shaking. The aggregates were approximately 240 microm in diameter. After 36 h of shaking, their shape became more rounded and their surfaces became smoother. No evidence of necrosis in the center of the aggregates was observed, although a small number of dead cells was scattered throughout the aggregates. After 24-36 h, aggregates of normal human fibroblasts were collected and reinoculated onto a scaffold composed of polyglycolic acid. which is used commercially as a scaffold for artificial skin, coated with collagen. The aggregates were successfully trapped to the mesh of polyglycolic acid and became attached within 24 h. Therefore, the aggregates could provide an alternative method for seeding fibroblasts to scaffold for an artificial skin, such as a mesh of polyglycolic acid.

Cell Aggregation↗
PubMed2001

In vitro organization of biohybrid rat liver tissue incorporating growth factor- and hormone-releasing biodegradable polymer microcapsules.

To enhance the liver-specific functions of rat hepatocyte aggregates without the addition of exogenous growth factors, polylactic acid-polyglycolic acid (PLGA)/gelatin microcapsules that release insulin, dexamethasone, epidermal growth factors, and glucagon were prepared and incorporated into the hepatocyte aggregates in suspension culture. Precoating the capsules with fibronectin enhanced the incorporation of the microcapsules into the hepatocyte aggregates. In a growth factor- and hormone-free culture medium, these microcapsule-containing aggregates showed a sustained cell number and an ammonium detoxification capacity compared with two types of control culture. One was the culture of microcapsule-free aggregates with albumin-containing control capsules and the other was the culture of capsule-free aggregates that were supplied with the same factors and hormones from the culture medium at concentration levels expected from the release kinetics of the microcapsules. Our new methodology demonstrates that the performance and duration of bioartificial liver systems can be enhanced due to a more efficient maintenance of cell number by using such growth factor- and hormone-releasing microcapsules.

Ammonia↗
PubMed2001

Angiographic and histologic changes in artery, vein and portal vein after placement of bare or covered Z-stent; an experimental study in dogs.

The aim of this study was to examine stenosis in the aorta, portal vein (PV), and inferior vena cava (IVC) after bare and covered Z-stent placement. Eight beagles underwent bare (n=4) or polytetrafluoroethylene (PTFE) covered (n=4) Z-stent placement in the aorta, PV, and IVC. Angiography was performed 1 and 3 weeks later to evaluate stenosis. The animals were sacrificed after 3 weeks for histopathologic examination. Angiographic findings revealed that stenosis in the bare stent group tended to be smaller than in the covered stent group in 3 vessels and stenosis tended to be smaller in the order of the aorta, PV and IVC in either group. In both groups, stenosis in the PV and IVC was mainly caused by organized thrombus. In addition, in the covered stent group, the space between the cover and native vessel wall (subgraft space) was formed and filled with neointima in every vessel. Preventing thrombus formation in the PV and IVC after bare and covered stent placement and reducing the subgraft space in the aorta after covered stent placement are important for minimizing stenosis.

Animals↗
PubMed2001

Immunolocalization of cytokines and growth factors in subacromial bursa of rotator cuff tear patients.

Inflammation in the subacromial bursa causes pain in patients suffering from rotator cuff tear, with this long-lasting inflammation leading to fibrosis and thickening of the subacromial bursa. Both inflammatory cytokines and mechanical stress, and impingement in the subacromial space, might induce and worsen this inflammation. However, little is known of the mechanism of this inflammation. In this study, we used immunohistological staining to demonstrate the expression of Interleukin-1 beta (IL-1 beta), Tumor necrosis factor alpha (TNF-alpha), transforming growth factor beta (TGF-beta), and basic fibroblast growth factor (bFGF) in subacromial bursa derived from the patients suffering from rotator cuff tear. On the other hand the expression of these inflammatory cytokines and growth factors were little detected only to a small degree in patients with anterior shoulder instability who did not have severe shoulder pain and impingement in the subacromial space. Our findings suggest that those inflammatory cytokines and growth factors may play an important role in inflammation of the subacromial bursa. Controlling the expression of these cytokines and growth factors might be important for treating patients suffering from shoulder pain due to rotator cuff tear.

Acromion↗
PubMed2001

Prostaglandin E2 regulates the expression of basic fibroblast growth factor messenger RNA in normal human fibroblasts.

Prostaglandin E2 (PGE2) has been reported to control angiogenesis and play an important role in wound healing in soft tissues, although the precise mechanism is still unknown. Since basic fibroblast growth factor (bFGF) has been reported to generate neovascularization, PGE2 and bFGF might work closely, or one might control the expression of the other. In this study, we demonstrate that PGE2 enhances the expression of bFGF in normal human fibroblasts, and that calcium ionophore, A23187, and adenylate cyclase activator, forskolin, also enhances the expression bFGF mRNA. These results suggest that enhancement of bFGF mRNA stimulated by PGE2 is mainly controlled through EP1 or EP2 and EP4 receptor. In conclusion, our findings suggest that the mechanism of PGE2-induced angiogenesis and wound hearing in soft tissue could be mediated by bFGF through EP1 or EP2 and EP4 receptor.

Adenylyl Cyclases↗
PubMed2001

[Penile metastasis from ascending colon carcinoma: a case report].

A 63-year-old man was referred to our hospital with the chief complaint of penile pain. Four hard tumors existed in his glans. He had priapism and perineal pain thereafter. Close examination revealed that the penile tumors were metastatic cancer from the adenocarcinoma of the ascending colon. Radical operation could not be performed because he was already suffering from peritonitis carcinomatosa. He died about four months after his first visit to our hospital.

Adenocarcinoma↗
PubMed2001

[Efficacy of a single-day administration of levofloxacin for the prevention of urinary tract infections after urogenital examinations and treatments for outpatients].

The clinical efficacy of a single-day oral administration of levofloxacin (LVFX) for the prevention of urinary tract infections (UTI) after urogenital examinations and treatments for outpatients was assessed. A single-day oral administration of LVFX, 100 mg three times a day, was compared to a single dose intra-muscular injection of 100 mg netilmicin sulfate or 100 mg dibekacin sulfate. Three of 219 cases (1.4%) and 7 of 304 cases (2.3%) contracted UTI in the single-day oral administration group and the single dose intra-muscular injection group, respectively. Adverse reactions were observed in 3 of 219 cases (1.4%) and 27 of 304 cases (8.8%) in the single-day oral administration group and the single dose intra-muscular injection group, respectively. In the single dose intra-muscular injection group, UTI and adverse reactions were more severe than in the single-day oral administration group. Therefore, a single-day oral administration of LVFX was superior to a single dose intra-muscular injection of netilmicin sulfate or dibekacin sulfate in the prevention of UTI with less probability of the adverse effects. A single-day oral administration of LVFX was concluded to be sufficient for the prevention of UTI caused by examinations and treatments for outpatients.

Administration, Oral↗
PubMed2001

Cardiac pacing as emergency care for serious bradyarrhythmia with circulatory shock.

Three cases of bradyarrhythmia with serious illness of extracardiac organs are reported. Case 1 had sick sinus syndrome. He was admitted to our hospital complaining of syncope and developed apnea. Case 2 had complete atrioventricular block and serious hepatic failure in the hospital. Case 3 had paroxysmal atrioventricular block. He complained of syncope which followed convulsions. Their symptoms might be due to circulatory shock caused by a lazy lower pacemaker from the ventricle. Emergent temporary pacing successfully improved the extracardiac organ dysfunction. Although their bradyarrhythmias were transient, permanent pacemakers were implanted to inhibit the recurrence. A quick temporary pacing should be indicated in patients with critical bradyarrhythmia like our cases for survival.

Aged↗
PubMed2000

N-[1-(2-Phenylethyl)pyrrolidin-3-yl]-1-adamantanecarboxamides as novel 5-HT2 receptor antagonists.

A series of 1-adamantanecarboxamides was synthesized and examined for their potency as a selective 5-HT2 receptor antagonist. We found (S)-N-[1-[2-(4-fluorophenyl)ethyl]pyrrolidin-3-yl]-1-adamantane carboxamide hydrochloride hydrate (10-(S), Y-39241) to have a high affinity and selectivity for 5-HT2 receptors, and this potent anti-platelet effect of Y-39241 was confirmed both in vitro and in vivo.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2000

Physiological role of the D-amino acid oxidase gene, DAO1, in carbon and nitrogen metabolism in the methylotrophic yeast Candida boidinii.

A methylotrophic yeast, Candida boidinii, exhibits D-amino acid oxidase activity (DAO, EC 1.4.3.3) during its growth on D-alanine as a sole carbon or a nitrogen source. The structural gene (DAO1), encoding DAO, was cloned from a genomic library of C. boidinii. The 1035-bp gene encoded 345 amino acids and the predicted amino acid sequence showed significant similarity to those of DAOs from other organisms. The DAO1 gene was disrupted in the C. boidinii genome by one-step gene disruption. The DAO1-deleted strain did not grow on D-alanine as a carbon source but did grow on D-alanine as a sole nitrogen source (with glucose as the carbon source). These results suggested that, while DAO is critically involved in growth on D-alanine as a carbon source, there should be another enzyme system which metabolizes D-alanine as a nitrogen source in C. boidinii. We also showed that the three C-terminal amino acid sequence of DAO, -AKL was necessary and sufficient for the import of DAO into peroxisomes.

Alanine↗
PubMed2000

Regulation and evaluation of five methanol-inducible promoters in the methylotrophic yeast Candida boidinii.

We isolated the promoter regions of five methanol-inducible genes (P(AOD1), alcohol oxidase; P(DAS1), dihydroxyacetone synthase; P(FDH1), formate dehydrogenase; P(PMP20), Pmp20; and P(PMP47), Pmp47) from the Candida boidinii genome, and evaluated their strength and studied their regulation using the acid phosphatase gene of Saccharomyces cerevisiae (ScPHO5) as the reporter. Of the five promoters, P(DAS1) was the strongest methanol-inducible promoter whose strength was approximately 1.5 times higher than that of the commonly used P(AOD1) in methanol-induced cells. Although the expression of P(AOD1) and P(DAS1) was completely repressed by the presence of glucose, formate-induced expression of P(FDH1) was not repressed by glucose. Expression under P(PMP47), another methanol-inducible promoter, was highly induced by oleate. The induction kinetics of P(PMP47) and P(DAS1) revealed that methanol induces the expression of peroxisome membrane protein Pmp47, earlier than the expression of matrix enzyme dihydroxyacetone synthase (Das1p), and that this information is contained in the promoter region of the respective gene. This is the first report which evaluates several methanol-inducible promoters in parallel in the methylotrophic yeast.

Acid Phosphatase↗