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Biomedical subjects

Y Sakai

Publications and source records attributed to Y Sakai.

At least 361 records · Page 20Linked to original sources
PubMed1997

Tacrine improves working memory deficit caused by permanent occlusion of bilateral common carotid arteries in rats.

Effect of tacrine, a cholinesterase inhibitor, on spatial acquisition deficit caused by permanent occlusion of bilateral common carotid arteries (2VO) was examined by using the conventional 8-arm and the 4-arm baited radial maze tasks in rats. Daily administration of tacrine (0.1 and 0.3 mg/kg, i.p.) 1 month after 2VO operation significantly improved the impaired spatial acquisition in the conventional maze task. This treatment also ameliorated the 2VO-induced working but not reference memory deficit in the 4-arm baited radial maze task. These results suggest that tacrine improvement of working memory deficit in the 2VO rats is due to stimulation of central cholinergic systems.

Animals↗
PubMed1997

NADPH-dependent reduction of ethyl acetoacetate coupled with ethanol oxidation in Kloeckera magna.

We evaluated the catalytic ability of 29 yeast strains to reduce ethyl acetoacetate (EA) in the presence of ethanol or glucose. In 18 yeast strains, the reduction in the presence of ethanol proceeded as well as in the presence of glucose. Among them, Kloeckera magna (AKU 4704) effectively catalyzed the NADPH-dependent reduction of EA in the presence of ethanol. In this reduction, 1 mol of EA was reduced by consuming 1 mol of ethanol. We found that the NADPH regeneration system responsible for EA reduction in K. magna was coupled with oxidation of acetaldehyde to acetic acid catalyzed by an NADP(+)-dependent aldehyde dehydrogenase.

Acetoacetates↗
PubMed1997

Ester synthesis by NAD(+)-dependent dehydrogenation of hemiacetal: production of methyl formate by cells of methylotrophic yeasts.

A water-soluble ester, methyl formate, was detected as a metabolite in the culture medium of methylotrophic yeasts. Methyl formate synthase, which catalyses NAD(+)-dependent dehydrogenation of the hemiacetal adduct of methanol and formaldehyde, catalyses the ester synthesis. The enzyme activity was induced on a methanol medium and was increased further by the addition of formaldehyde. In the reaction system using intact cells of Pichia methanolica AKU 4262, 135 mM (8.1 g/liter) methyl formate was produced from 2 M methanol. This is a new biological process for ester synthesis that couples spontaneous formation of hemiacetal and alcohol dehydrogenase.

Esters↗
PubMed1997

Desmopressin stimulation test for diagnosis of ACTH-dependent Cushing's syndrome.

We evaluated the usefulness of a desmopressin (DDAVP) test in the diagnosis of ACTH-dependent Cushing's syndrome. After an intravenous injection of 5 microg DDAVP, plasma ACTH levels increased to more than 200% of the basal levels in 10 of 10 patients with Cushing's disease, but remained less than 150% in all of 11 normal subjects, 3 patients with Addison's disease, 5 cases of Cushing's disease in remission, and 3 patients with ectopic ACTH syndrome. Peak levels of plasma cortisol after the DDAVP stimulation were 159 +/- 14% in the patients with Cushing's disease, and less than 150% of the basal levels in the other 5 groups. We also found a case of Cushing's disease with periodicity which responded to DDAVP only in the active stage. In vitro studies revealed that DDAVP directly stimulates ACTH release from corticotropic adenoma cells through V1b but not V2 vasopressin receptors. In conclusion, the DDAVP stimulation test, i.e., determination of plasma ACTH levels after 5 microg DDAVP injection, seems useful for discriminating Cushing's disease from normality, and may serve to facilitate the differentiation between Cushing's disease and ectopic ACTH syndrome.

Adenoma↗
PubMed1997

[Improvements in mental and physical status of elderly patients with dementia after institutionalization--assessment with a minimum data set].

Using a Minimum Data Set, we studied how the mental and physical status of elderly people with dementia was modified by institutionalization. We assessed patients with dementia at the time of their admission in Kyoto Higashiyama geriatric hospital, and again three months later. On admission, both mental and physical problems were noted with a Resident Assessment Protocols. The former included cognitive loss/dementia, delirium, behavioral problem, activities, and mood state; the latter included visual function, activities of daily living (functional), urinary incontinence and indwelling catheter, nutritional status, dehydration/fluid maintenance, and dental care. Three months later, marked improvements were observed in 8 areas: delirium, psychological well-being, mood state, activities, urinary incontinence and indwelling catheter, nutritional status, dehydration/fluid maintenance and dental care. Cognitive loss/dementia and visual function were changed little. The unchanged areas were considered to be "core" manifestations of dementia, and those that changed were believed to reflect emotional problems and to be affected by the environment. Therefore, individualized care for elderly institutionalized patients with dementia should focus on these "peripheral" problems rather than on those that cannot be changed.

Activities of Daily Living↗
PubMed1997

GE3, a novel hexadepsipeptide antitumor antibiotic, produced by Streptomyces sp. I. Taxonomy, production, isolation, physico-chemical properties, and biological activities.

GE3, a novel cyclic hexadepsipeptide antibiotic, was isolated from the culture broth of Streptomyces sp. GE3. GE3 was weakly active against some Gram-positive and Gram-negative bacteria and showed potent cytotoxicity against human tumor cell lines. GE3 also exhibited antitumor activity against human pancreatic carcinoma, PSN-1, in vivo. GE3B, a linear peptide form of GE3, which was isolated from the same culture broth with GE3, showed no antibiotic and cytotoxic activities, suggesting the necessity of the cyclic structure of GE3 for its biological activities.

Animals↗
PubMed1997

[Lesion-related factors associated with restenosis after percutaneous transluminal coronary angioplasty in the absence of patient-related factors].

Restenosis after percutaneous transluminal coronary angioplasty (PTCA) is one of the biggest problems in the treatment of coronary artery disease. Although many studies have been performed on lesion-related factors, they are influenced by patient-related factors such as smoking, hyperlipidemia, and the presence of acute coronary syndrome. In this study, lesion-related factors were assessed in the absence of other factors by univariate and multivariate analysis. One hundred and nine lesions were reviewed in 37 consecutive patients with both restenotic lesion(s) and non-restenotic one(s) confirmed by coronary arteriography performed 4.4 +/- 2.2 months after PTCA. Angiographic findings before and immediately after angioplasty were compared between restenotic and non-restenotic lesions. The overall lesion-restenosis rate was 42%. Univariate analysis revealed that calcified lesions (p < 0.05), multiple irregularities (p < 0.01) before angioplasty, residual percentage stenosis (p < 0.05), and angiographical intraluminal haziness (p < 0.05) were related to restenosis. Intimal dissection after PTCA was not associated with restenosis. Multivariate analysis with multiple logistic regression revealed that multiple irregularities (t = 2.8) was the most predictive of restenosis before PTCA and residual percent stenosis (t = 2.6) after the procedure. Coronary lesions with calcification or multiple irregularities indicate high risk of restenosis after PTCA. Optimal dilatation of the lesions without intraluminal haziness regardless of intimal dissection is important to prevent restenosis.

Aged↗
PubMed1997

Solitary and multiple pyogenic liver abscesses: characteristics of the patients and efficacy of percutaneous drainage.

OBJECTIVES: Although percutaneous drainage has emerged as one of the first line of therapies for pyogenic liver abscesses, the presence of multiple abscesses may warrant surgical drainage, which remains controversial in the literature. We studied whether the multiplicity of the lesions influences the outcome of the treatment. METHODS: Ultrasonography-guided percutaneous drainage was carried out in 48 patients with pyogenic liver abscesses. The abscesses were solitary in 38 patients and multiple (two to seven lesions) in 10 patients. Clinical characteristics and the efficacy of the treatment were compared between these two groups. RESULTS: Biliary diseases and malignancies were more frequently observed in the solitary cases than multiple cases. A past history of surgery for cholelithiasis was seen exclusively in the multiple cases. E. coli was more frequently cultured from the abscesses in the multiple cases. Three of the multiple cases required more than a single catheter. All of the multiple cases and 36 of the 38 solitary cases were successfully treated. Two patients died of biliary peritonitis as a complication of the procedure, and three died of other underlining diseases. CONCLUSION: Ultrasonography-guided percutaneous drainage is effective even in patients with multiple pyogenic liver abscesses by adding catheters to obtain sufficient drainage.

Adult↗
PubMed1997

[Proctocolectomy with ileal W pouch anal anastomosis for ulcerative colitis].

Restorative proctocolectomy with ileal pouch anal anastomosis, which is a relatively new procedure, has become a standard procedure for ulcerative colitis (UC) requiring surgical management. The main impact of this procedure is to cure patients of disease and to avoid permanent ileostomy, preserving better defecatory function and acceptable QOL. Some key aspects of our surgical procedure are as follows: 1) two or three separate staged operation, 2) W-shaped reservoir, 3) distal rectal mucosectomy and handsewn ileo-anal anastomosis, 4) short muscular cuff, and 5) temporary diverting ileostomy. Staged operation and diverting ileostomy are helpful to decrease risk of pelvic infection. Total removal of the rectal mucosa is necessary to cure the disease, and shorter muscular cuff decreases operating time and bleeding and thus the risk of pelvic sepsis. The W-shaped reservoir described by Nicholls brings both spontaneous defecation and improved function. We have adopted ileal W-pouch among several types of reservoir to 58 patients with UC since 1984, and found that a large and wide reservoir might allow better defecatory function. There were no cases of serious complications and no needs to remove the reservoir. Mean daily stool frequency was gradually decreased with time, and 4.9 stools per 24 hours at present day, and clinical score of neorectal function also gradually improved according to reduction of stool frequency. Seventy three percent of patients felt their defecatory function satisfactory and 89% of the patients recovered acceptable QOL no less than that obtained during the medically treated period.

Adolescent↗
PubMed1997

[Long-term late results of pericardiectomy for constrictive pericarditis].

Twenty-four cases of the constrictive pericarditis were operated on pericardiectomy from 1966 to 1990. One case died because of massive bleeding, LOS, and respiratory failure immediately after the operation. A long-term follow up study was performed up to 27 years (mean 13.1 years) in other cases. Ten cases died during the follow up period (cardiac: 6, non cardiac: 4). Five cases of the cardiac deaths had major complications: tabes dorsalis, chronic respiratory failure, pacemaker implantation, mitral regurgitation, emergency operation at high age (78 years old). The survival rates of 5, 10, and 15 years were 85%, 67%, and 58.2%, respectively (Kaplan-Meier). All of survival cases are now in NYHA I or II class in satisfactory. We concluded that pericardiectomy is a very effective treatment for constrictive pericarditis but a more careful follow up is required especially in cases complicated with other major problems because cardiac function is not so recovered as normal level after surgery due probably to readhesion and fibrotic changes of the myocardium.

Adult↗
PubMed1997

[A new reconstructive procedure, interposition of a jejunal pouch after proximal gastrectomy].

In this chapter we mention the significance or advantage of the new reconstructive procedure, interposition of a jejunal pouch after proximal gastrectomy. Instead of oesophagogastrostomy which often brought many postoperative complications, various techniques of anastomosis such as conventional jejunal interposition or double tract method were contrived. Although these techniques could reduce the incidence of postoperative problems such as reflux oesophagitis, it is very difficult to examine or remedy beyond the oesophagojejunostomy site after surgery. On the other hand, interposition of a jejunal pouch showed us many advantages. The volume of reconstructed stomach was adequate and the patients could eat enough actually. In case of need, endoscopic fiber could enter the remnant stomach or duodenum very easily. This is the big advantage for the treatment of the upper GI and hepato-biliary pancreatic diseases endoscopically or radiologically after proximal gastrectomy. For these reasons, we usually use interposition of a jejunal pouch between the oesophagus and remnant stomach after proximal gastrectomy.

Anastomosis, Surgical↗
PubMed1997

[Development of a bioartificial liver using porcine hepatocyte spheroids].

We have discussed hereby about the latest studies on bioartificial liver systems including those examined in human clinical trials. Based on the discussion and in order to meet the present requirement of clinical sides to the system, that is, maximal metabolic capacities up to 6 hours of plasma perfusion treatment, we have developed a new bioartificial liver based on high-cell density suspension perfusion culture of porcine hepatocyte spheroids, which have two or three times higher functional expressions that those of conventional cultures. The module developed can retain a large number of hepatocytes(4 x 10(9)) in 150 mL volume without any functional deterioration usually accompanied by high-cell density cultivation, even when compared with small-scale dish-level cultures.

Animals↗
PubMed1997

[Surgical therapy for hepatocellular carcinoma with liver cirrhosis].

Approximately 80% of hepatocellular carcinoma (HCC) patients in Japan have associated liver cirrhosis, which increases the difficulty of surgical treatment. Liver dysfunction associated with liver cirrhosis is one of the most important predictive prognostic factors for HCC patients. Percutaneous ethanol injection therapy (PEIT) is useful for patients with small HCC or with poor hepatic functional reserve. Transcatheter arterial chemoembolization (TACE) is also useful both for patients with unresectable HCC and patients with multiple intrahepatic recurrence. Liver resection, however, lead to better outcome than other treatments when liver function is maintained after surgery. To determine operative procedures, it is important to evaluate the exact function of remnant liver, based on the preoperative liver function test and the evaluation of tumor character. For advanced HCC patients with vascular invasion, non-surgical treatments such as PEIT or TACE are not indicated, and surgical intervention can be an effective modality to improve their survival. Improvements of surgical technique and perioperative management have decreased fatal complications at a major liver resection and allowed us to carry out liver resection on patients with advanced HCC.

Carcinoma, Hepatocellular↗
PubMed1997

Prevention of amyloid-like deposition by a selective prolyl endopeptidase inhibitor, Y-29794, in senescence-accelerated mouse.

Our study was performed to assess the hypothesis that prolyl endopeptidase (PEP) would be functionally involved in the senescence-accelerated amyloid formation and that long-term inhibition of prolyl endopeptidase would suppress the progression of A beta-like deposition in the hippocampus of the senescence-accelerated mouse (SAM). Granular structures of A beta-LI were observed in the hippocampus and around cerebral microvessels of the SAM after immunohistochemical staining with specific anti-A beta antibody. Repeated treatment of the SAM with Y-29794 (1, 10, 20 mg/kg, p.o.), a specific inhibitor of prolyl endopeptidase, significantly reduced the number and density of A beta-positive granular structures in the hippocampus of the SAM, after digital image analysis with NIH Image software. Furthermore, the characteristic biphasic distribution of the digitized density of the granules was significantly modulated after the treatment with Y-29794. These results suggest that chronic treatment of the SAM with Y-29794, a nonpeptide inhibitor of prolyl endopeptidase, prevents the progression of A beta-like deposition in the hippocampus of the SAM.

Aging↗