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Biomedical subjects

Y Uno

Publications and source records attributed to Y Uno.

At least 91 records · Page 5Linked to original sources
PubMed1997

Infarct size-reducing effect of ischemic preconditioning is related to alpha1b-adrenoceptors but not to alpha1a-adrenoceptors in rabbits.

In rabbits and rats, both stimulation of alpha-adrenoceptors and ischemic preconditioning (PC) reduce infarct size. Activation of alpha1b-adrenoceptors play an important role in the PC effect on ventricular function in rats. However, the alpha1-adrenoceptors have not been reported to be related to the PC effect in rabbits, because the infarct size-reducing effect of PC is not blocked by the nonselective alpha-adrenoceptor antagonist, phenoxybenzamine (POB) or by the alpha1-adrenoceptor antagonist, BE2254. However, we speculated that alpha1b-adrenoceptors but not alpha1a-adrenoceptors may be related to the infarct size-reducing effect of PC in rabbit hearts. Thus we examined in rabbits whether the alpha1b-adrenoceptor blocker chloroethylclonidine (CEC), the alpha1a-adrenoceptor blocker 5-methylurapidil (5-MU), the selective alpha1-adrenoceptor antagonist bunazosin (BN), and the nonselective apha-adrenoceptor antagonist phenoxybenzamine (POB) can block the PC effect on infarct size. Eighty-eight anesthetized open-chest Japanese white male rabbits were subjected to 30-min coronary occlusion and 48-h reperfusion. In five PC groups, the rabbits were subjected to a single 5-min occlusion and 5-min reperfusion before 30-min sustained ischemia. In the PC groups, those with CEC (3 mg/kg, n = 10), 5-MU (3 mg/kg, n = 10), BN (0.3 mg/kg, n = 10), POB (4 mg/kg, n = 10), or placebo saline (n = 10) were pretreated before PC. In the non-PC groups, those with CEC (3 mg/kg, n = 7), 5-MU (3 mg/kg, n = 7), BN (0.3 mg/kg, n = 7), POB (4 mg/kg, n = 7), or placebo saline (n = 10) were pretreated before 30-min sustained ischemia. After a 48-h reperfusion, the infarct size was measured histologically and expressed as a percentage of the area at risk. PC caused a marked reduction of infarct size as compared with the non-PC control (10 +/- 3% vs. 42 +/- 2%; p < 0.05). The PC effect was completely blocked by CEC (36 +/- 2%) and by BN (42 +/- 4%) but not by 5-MU (14 +/- 1%) or POB (13 +/- 2%). None of the drugs by itself affected the infarct size. Stimulation of alpha1b-adrenoceptors but not of alpha1a-adrenoceptors during PC plays an important role in the PC effect on infarct size. This may explain the previous confusion concerning the PC blocking effect of various alpha1-blockers.

Adrenergic alpha-Antagonists↗
PubMed1997

Effects of adrenaline infusion on plasma lipids and noradrenaline levels in rabbits with adriamycin-induced cardiomyopathy.

1. We investigated the acute effects of adrenaline infusion on plasma lipid levels in vehicle- and adriamycin-treated rabbits. Lipids were measured before and 30 and 60 min after the commencement of continuous intravenous administration of adrenaline (0.06 microgram/kg per min) or saline in pentobarbital-anaesthetized rabbits. 2. Adrenaline infusion significantly increased plasma free fatty acid (P < 0.05) and noradrenaline (NA) levels (P < 0.05) in vehicle-treated control rabbits, but not in adriamycin-treated rabbits. However, adrenaline had no effect on plasma total cholesterol, free cholesterol, high-density lipoprotein-cholesterol, triglyceride or phospholipid levels. 3. Pretreatment with propranolol almost completely inhibited increased plasma free fatty acid and NA levels associated with adrenaline infusion, suggesting that adrenaline increases plasma free fatty acid and NA levels via the stimulation of beta-adrenoceptors in vehicle-treated rabbits. 4. It is suggested that both the production of plasma free fatty acids and the release of NA via the activation of beta-adrenoceptors is reduced in rabbits with adriamycin-induced cardiomyopathy. This may be related to the down-regulation of beta-adrenoceptors caused by elevated plasma NA levels induced by cardiac failure.

Animals↗
PubMed1997

Phenylmercury transport mediated by merT-merP genes of Pseudomonas K-62 plasmid pMR26.

The merB-merA-deleted plasmid pMRD141 which contains the intact merT-merP genes of pMRA17 conferred bacterial hypersensitivity not only to Hg2+ but also to C6H5Hg+. The bacterium with pMRD141 took up significantly more C6H5Hg+ than its isogenic strain with the cloning vector Bluescript II. The hypersensitivity to C6H5Hg+ seems to be based on hyperaccumulation of toxic C6H5Hg+ in the absence of detoxifying enzymes encoded by merB and merA. Our results show that bacterial transport of C6H5Hg+ into the cytoplasm is regulated by merT-merP genes.

Bacterial Proteins↗
PubMed1997

Cold snare excision is a safe method for diminutive colorectal polyps.

Cold snare excision (CSE) has proved to be an effective method for the destruction of diminutive polyps of the colon and rectum. We investigated the correlation between polyp size and bleeding time at the resected end after CSE, and also an appropriate measuring method using CSE. Eighty patients with single polyps were examined. Each polyp was identified as being 5 mm in diameter or smaller using the open-biopsy forceps technique (OBFT). The size of the polyp was calculated using our measuring system (SMS). Of the polyps identified as being 5 mm in diameter or less using OBFT, 15% were 6 mm or more using the SMS. CSE was performed for each polyp, and the time taken for the hemostasis (bleeding time of the CSE; BTCSE) was determined. In seventy-seven polyps that were 6 mm or smaller in SMS, a correlation was noted between SMS and BTCSE. In three polyps that were 7 mm or more by SMS, hemostasis took 10 min or more after CSE, and required electrocoagulation. These results suggest that CSE is a safe method for the removal of polyps determined to be 6 mm in diameter or smaller using the SMS.

Aging↗
PubMed1997

[Drug consultation and at home care--the present situation and the point at issue in our hospital].

We began drug consultation in our hospital and at home care about one year ago, because of progress in the quality of medical care. As the method for drug consultation, we tried to educate patients using our own pamphlets. It was assumed that the education was important not only for the patients but also for their family. Again, it was assumed that the usefulness of a conference with doctors, nurses, MSW and us made for better compliance in taking drugs, assured early detection of side effects and better management of the disease. With home care, it is supposed that the drug consultation will be carried out by clinical pharmacists will make for progress in the quality of medical care.

Home Care Services, Hospital-Based↗
PubMed1997

[Binocular functions in amblyopia and strabismus].

Regarding the changing trends in the concept, definition, etiological classification, and criteria for diagnosis of amblyopia, we reviewed a total of 4,693 cases of amblyopia seen during the past 37 years. The amblyopia was divided into four types: strabismic, anisometropic, ametropic, and form vision deprivative. There was a definite trend for the incidence to decrease and for the diagnosis to be made during earlier age in recent years. Although favorable recovery of visual acuity is obtained after treatment of amblyopia and strabismus, there are difficulties in obtaining good binocular functions in early-onset amblyopia and strabismus. This feature was evaluated in regard to motion perception asymmetry (MPA) and binocular depth from motion (DFM). Many cases of early-onset amblyopia and strabismus showed no disparity stereopsis, or position stereopsis, in spite of the presence of DFM. The MPA appeared to be closely related to early-onset esotropia regardless of age, while it disappeared and motion perception became symmetric 4 to 5 months after birth in normal infants. The DFM seemed to play an important role in maintaining good motor alignment for several years after surgery. I developed a checkerboard pattern stimulator in 1978. This method proved to be useful in developing binocular functions and motor alignment by applying simultaneous bifoveolar stimulation and anti-suppression. Extensive exposure to the stimulation was essential for therapeutic success.

Adolescent↗
PubMed1996

Factors that influence bleeding in superficial-type colorectal tumors: study of endoscopic and histologic correlates.

To clarify the mechanisms responsible for superficial-type colorectal tumor (STT) bleeding, 74 STTs were studied to determine whether their size, shape, surface area features, colorectal site, and level of invasion were correlated with bleeding. The bleeding rate, the proportion of specimens from patients with positive fecal occult blood test (FOBT) results relative to the total number of specimens in each morphological group and probability of an STT being an invasive submucosal carcinoma were positively correlated with tumor size, and bleeding was more common in submucosal than in intramucosal lesions. Logistic regression analysis indicated that the level of submucosal invasion had a significant influence on bleeding. It was also found that the length of erosion on the surface of STTs was significantly greater in bleeding tumors, and that the potential for invasion into the submucosa increased with the area of erosion.

Colon↗
PubMed1996

Mental retardation and colorectal disease: colonoscopic mass screening to determine whether the risk of adenomatous polyposis syndrome is increased in the mentally retarded.

Adenomatous polyposis syndrome (APS) is often associated with mental retardation, but whether there is a causal relationship between the two is unknown. This study was initiated to determine colorectal disease rates among mentally retarded subjects and whether they are at risk of developing colorectal cancer. Colonoscopic mass screenings were conducted to detect the presence of colonic neoplasms in 134 patients housed at an institution for the mentally retarded. The ages of these subjects ranged from 32 to 69 years (mean: 44 years) and their IQ scores ranged from 35 to 63. Screening presented no difficulties and the colonic regions up to the caecum were inspected in all patients. Polyps were found in 24 patients (17.9%), an abnormal fixation in two (1.5%), melanosis coli in two (1.5%) and haemorrhoids in two (1.5%). Thirteen subjects had a single polyp (54%), five had two polyps (21%), three had three polyps (12.5%) and three had four polyps (12.5%). Twenty one polyps were less than 5 mm in diameter, 14 were 5-9 mm and nine were 10 mm or larger. No cases of APS were detected during this mass screening programme. The mentally retarded patients in this study were not found to be at a high risk of developing either APS or colon cancer.

Adenomatous Polyposis Coli↗
PubMed1996

Enzymes in intestinal juice from patients with liver diseases and colon polyps: measurement of bilirubin, alkaline phosphatase, aspartate aminotransferase and lactate dehydrogenase.

Since the amounts of hepatogenous enzymes discharged into the intestinal tract remain unknown, this study was initiated to evaluate the amounts of the enzymes in the intestinal tract. Whole gut lavage fluid (polyethyleneglycol electrolyte solution) was administered orally to 42 subjects, consisting of 5 patients with hepatoma, 10 with chronic hepatitis, 10 with colon polyps, and 17 control subjects without liver disease. Two hr after the large intestinal lavage, the digestive tract juice was aspirated by colonoscopy, and the bilirubin (Bil), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) in the aspirates were measured. A positive correlation between the AST and LDH values was found, and a significant difference in these values between the hepatic disorders and the normal controls was noticed. A significant positive correlation between the ALP and Bil values was found, and a statistical difference in these values between the group of colon polyps and the controls and other groups was observed. This lavage fluid technique enables to estimate the amounts of hepatic enzymes discharged into the intestinal tract, thereby opening a new avenue for future enzyme research.

Adult↗
PubMed1996

[Successful direct embolectomy for acute massive pulmonary thromboembolism].

A 35-year-old woman was bedridden because of a fall and developed pulmonary embolism after venous thromboembolism of lower extremity. Although anticoagulation therapy was immediately carried out, hemodynamics deteriorated gradually into the state of class IV in Green-field's classification. As a result, an urgent surgical procedure was performed. Under moderate hypothermic cardio-pulmonary bypass, the aorta was cross-clamped and the pulmonary artery was opened. An 18 gram clot was taken out directly and other small pieces of clot were removed with a fiberscope, a Fogarty catheter and an aspirating tube. After surgery the patient recovered from symptoms efficiently. Some cases of acute pulmonary thromboembolism have been reported, however, the generalized classification and surgical indication for this disease have not been established yet. But, as all of reports mentions, surgical procedure is recommended positively to these cases that resist anticoagulation therapy.

Acute Disease↗
PubMed1995

The in vivo-in vitro replicative DNA synthesis (RDS) test with hepatocytes prepared from male B6C3F1 mice as an early prediction assay for putative nongenotoxic (Ames-negative) mouse hepatocarcinogens.

To assess the efficacy of the in vivo-in vitro hepatocyte replicative DNA synthesis (RDS) test as a short-term assay, 41 putative nongenotoxic (Ames-negative) mouse hepatocarcinogens, as well as 31 noncarcinogens, were examined using male 8-week-old B6C3F1 mice and an in vitro [methyl-3]thymidine-incorporation technique. Animals were exposed to the maximum tolerated dose (MTD) and 1/2 MTD of each chemical by gavage and after 24, 39 or 48 h, hepatocytes were prepared with a collagenase-perfusion technique. Assessment of the distribution of spontaneous RDS in a total of 337 control mice gave an average incidence of 0.15 +/- 0.08% within the range of 0 to 0.39% (mean +/- 3 x SE) with a 99.7% probability. Values of 0.4% or more for RDS incidences induced by test samples were therefore judged as indicating a positive response in our RDS test. Under the experimental conditions applied, 32 of 41 putative nongenotoxic hepatocarcinogens gave clear positive responses (positive sensitivity: 78%), and of 31 noncarcinogens 25 samples gave negative responses (negative specificity: 81%), thus giving an overall concordance for the RDS test with long-term findings of 79%.

Administration, Oral↗
PubMed1995

Endoscopic and histologic correlates of colorectal polyp bleeding.

Until now, the exact mechanism of bleeding from colorectal polyps has not been demonstrated. The present study aimed to identify macroscopic factors and the main source of polyp bleeding. One hundred fifty-seven cases of single colorectal polyp from a variety of clinical situations were investigated to determine whether surface area, shape, color, and location in the colon were correlated with a positive result in the fecal occult blood test. We also searched for the site of bleeding on the surface of polyps under a dissecting microscope and investigated the relationship between bleeding and microerosion and thin surface epithelium on the maximal vertical cross-section of the polyp. The presence of fecal occult blood was found to be correlated with the surface area of colonic polyps. We demonstrated that a red color tone of polyps was caused largely by microerosion and that the area of both microerosion and thin surface epithelium was significantly larger on polyps associated with a positive fecal occult blood test result. The extent of microerosion and thin surface epithelium was found to be correlated with the polyp surface area and villous component. These observations strongly suggest that the area of microerosion and thin surface epithelium tends to increase as the surface area expands, resulting in a higher rate of detection of polyps with malignant potential by the fecal occult blood test.

Adenocarcinoma↗
PubMed1995

Internal representations of the motor apparatus: implications from generalization in visuomotor learning.

Recent computational studies have proposed that the motor system acquires internal models of kinematic transformations, dynamic transformations, or both by learning. Computationally, internal models can be characterized by 2 extreme representations: structured and tabular (C. G. Atkeson, 1989). Tabular models do not need prior knowledge about the structure of the motor apparatus, but they lack the capability to generalize learned movements. Structured models, on the other hand, can generalize learned movements, but they require an analytical description of the motor apparatus. In investigating humans' capacity to generalize kinematic transformations, we examined which type of representation humans' motor system might use. Results suggest that internal representations are nonstructured and nontabular. Findings may be due to a neural network model with a medium number of neurons and synapses.

Adult↗
PubMed1995

Bone resorption in human cholesteatoma: morphological study with scanning electron microscopy.

The detailed mechanism of bone resorption in cholesteatoma was investigated by means of eroded ossicles obtained during middle ear surgery for cholesteatoma. In the light microscopic study, multinucleate osteoclasts with ruffled borders were found in contact with the eroded bone, which appeared to be osteoclastic lacunae. Scanning electron microscopy revealed the lacunae to be many absorption bays, 30 to 100 microns in diameter, clustered on the surface of eroded areas. Numerous cone-shaped stubs of digested collagen fiber bundles, consisting of scores of collagen fibrils and degenerated extracellular organic substances, were visible at higher magnification on the bottom of the absorption bay. The pattern of fusion and twining of the disarranged collagen fibrils at the top of the partly digested fiber bundles was clearly rendered by the alkali-water maceration method for scanning electron microscopy. We infer from the morphological evidence that osteoclastic resorption may be one of the major mechanisms of bone destruction in cholesteatoma, and that demineralization and degeneration of extracellular organic substances precede disruption of collagen fibrils at the front of bone resorption.

Bone Resorption↗
PubMed1995

Modulation of left ventricular iodine-125-MIBG accumulation in cardiomyopathic Syrian hamsters using the renin-angiotensin system.

UNLABELLED: Genetically inbred cardiomyopathic hamsters were examined to investigate the mechanism of reduced myocardial accumulation of metaiodobenzylguanidine (MIBG) in the cardiomyopathic heart. METHODS: Bio 14.6 Syrian hamsters (hypertrophic stage: n = 15, early heart failure stage: n = 17) and control F1b strain golden hamsters (n = 36) were injected with 296 kBq of [125I] MIBG and killed 30 min or 4 hr later. Thirty-three of these hamsters were pretreated with 10 mg/kg of desipramine to determine non-neuronal MIBG accumulation. To evaluate the nonexocytotic MIBG release from nerve endings, desipramine was administered to four Bio 14.6 hamsters 15 min after [125I]MIBG injection. To determine the role of the activated renin-angiotensin system (RAS) in MIBG washout from sympathetic nerve terminals in cardiomyopathy at early heart failure stage, 10 mg/kg/day cilazapril, an angiotensin-converting enzyme inhibitor, was given orally to 7 controls and 16 cardiomyopathic hamsters for 16 wk. RESULTS: In the absence of desipramine pretreatment, left ventricular [125I]MIBG accumulation 4 hr after injection was 0.376% +/- 0.015 %kg dose/g (mean +/- s.e.m.) in the hypertrophic hamsters (versus 0.418 +/- 0.019 in controls of the same age; ns), and 0.195 +/- 0.025 in early heart failure hamsters. Treatment with cilazapril partially restored MIBG accumulation in the Bio 14.6 hamsters but did not affect the controls. CONCLUSION: Decreased [125I]MIBG accumulation in cardiomyopathic hamsters during the early heart failure stage is caused by neuronal release which is partially modulated by the activated RAS.

3-Iodobenzylguanidine↗
PubMed1994

The ste13+ gene encoding a putative RNA helicase is essential for nitrogen starvation-induced G1 arrest and initiation of sexual development in the fission yeast Schizosaccharomyces pombe.

When the fission yeast Schizosaccharomyces pombe is starved for nitrogen, the cells are arrested in the G1 phase, enter the G0 phase and initiate sexual development. The ste13 mutant, however, fails to undergo a G1 arrest when starved for nitrogen and since this mutant phenotype is not suppressed by a mutation in adenylyl cyclase (cyr1), it would appear that ste13+ either acts independently of the decrease in the cellular cAMP level induced by starvation for nitrogen, or functions downstream of this controlling event. We have used functional complementation to clone the ste13+ gene from an S. pombe genomic library and show that its disruption is not lethal, indicating that, while the gene is required for sexual development, it is not essential for cell growth. Nucleotide sequencing predicts that ste13+ should encode a protein of 485 amino acids in which the consensus motifs of ATP-dependent RNA helicases of the DEAD box family are completely conserved. Point mutations introduced into these consensus motifs abolished the ste13+ functions. The predicted Ste13 protein is 72% identical to the Drosophila melanogaster Me31B protein over a stretch of 391 amino acids. ME31B is a developmentally regulated gene that is expressed preferentially in the female germline and may be required for oogenesis. Expression of ME31B cDNA in S. pombe suppresses the ste13 mutation. These two evolutionarily conserved genes encoding putative RNA helicases may play a pivotal role in sexual development.

Adenosine Triphosphate↗