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Biomedical subjects

Y Uno

Publications and source records attributed to Y Uno.

At least 19 recordsLinked to original sources
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↗
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↗
PubMed1994

Modelling of movement of the lamprey: control of oscillators.

This article discusses the control methods of the central pattern generator (CPG). First a control model of the CPG is presented using 2 oscillators, and we suggest that phasic modulation to the CPG by means of phasic information is effective for controlling the phase difference between oscillators. Next, two models for controlling the CPG of a lamprey are proposed. One model describes a control system from the brain stem, in which the reticulospinal neurons control the CPG by receiving feedback signals and sending control signals to the neck region of the CPG. The other is a model for learning an localized control system to generate a desired motor pattern. By means of these models, a role of the efference copy is suggested.

Animals↗
PubMed1994

An in vivo-in vitro replicative DNA synthesis (RDS) test using rat hepatocytes as an early prediction assay for nongenotoxic hepatocarcinogens screening of 22 known positives and 25 noncarcinogens.

To evaluate the applicability of an in vivo-in vitro replicative DNA synthesis (RDS) test using rat hepatocytes, we conducted the RDS test with 22 nongenotoxic (Ames-negative) hepatocarcinogens and 25 noncarcinogens under our standardized conditions and judgement criteria. Compared to controls (RDS incidence of under 1.0%), the RDS test gave positive results for 18 hepatocarcinogens (positive sensitivity: 82%), and negative results for 20 noncarcinogens (negative specificity: 80%), and thus the overall concordance was 81%. These findings strongly suggest that the RDS test is an extremely useful method for early detection of nongenotoxic hepatocarcinogens.

Animals↗
PubMed1994

Malignant melanoma of the nasal cavity.

We report a case of amelanotic melanoma arising in the nasal cavity and paranasal sinuses, that could not be positively diagnosed as malignant melanoma before the patient's death in spite of repeated biopsies both from primary and metastatic lesions, including ultrastructural examination and immunohistochemical staining for S-100 protein with usual polyclonal antibody. The patient died of rapid wide-spread dissemination of the tumor. In autopsy specimens, melanin pigment was detected, for the first time, by the Fontana's silver stain. The posthumous diagnosis of malignant melanoma was immunohistochemically confirmed for the specific antibodies, anti alpha-subunit of S-100 protein antibody and SK-46 (original antibody for melanoma made at the Department of Pathology, University of Gunma School of Medicine) from specimens obtained while alive. The application of a specific antibody for S-100 protein is recommended as useful for the diagnosis of malignant melanoma even when routine immunohistochemical procedures fail to demonstrate S-100 protein.

Aged↗
PubMed1994

Colonoscopic polypectomy with local injection of methylene blue.

For safer and complete colonoscopic polypectomy of large broad-based adenomas, we attempted submucosal injection of methylene blue before electrosurgical snare excision. Twenty-five large broad-based sessile adenomas 20 mm or more in diameter were resected. Methylene blue was injected about 2 mm away from the edge of the lesion. After injection, the lesion appearing as a blue bleb was resected by snare polypectomy. All the lesions were completely resected by single-step polypectomy. During and after polypectomy, no complication occurred. Endoscopic resection of large sessile adenomas with the aid of submucosal injection of methylene blue thus appears to be safe and effective.

Adenomatous Polyps↗
PubMed1993

Protein S Tokushima: an abnormal protein S found in a Japanese family with thrombosis.

An abnormal protein S (PS) was found in a Japanese family with a high incidence of thrombosis. The proband is a woman who was born in Tokushima Prefecture. She had superior sagittal sinus thrombosis, thrombophlebitis of the left leg, and thrombosis of the placenta. She had a normal plasma level of free PS antigen but decreased PS activity. Her mother and aunt also had thrombophlebitis of the leg, and together with four other family members also showed a normal level but decreased activity of PS. This suggests that hereditary dysfunction of PS is inherited in this family as an autosomal dominant trait. The proband's PS appears to have a slightly higher molecular weight than normal PS both in the intact and modified form, suggesting that it has a molecular defect on the carboxyl-terminal side of the thrombin-sensitive site. This abnormal PS with apparently unique characteristics was named PS Tokushima.

Adult↗