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Biomedical subjects

Y Uno

Publications and source records attributed to Y Uno.

At least 109 records · Page 6Linked to original sources
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↗
PubMed1994

[Two cases of tuberculous constrictive pericarditis].

Case 1 was a 79-year-old male suspected of tuberculous constrictive pericarditis. He was admitted to our hospital because of surgical treatment. His heart failure was NYHA IV. Culture of pleural effusion and pericardial effusion was negative. But ADA level in pericardial effusion was found to be increased. So tuberculosis was suspected. Cardiac catheterization date was compatible with constrictive pericarditis. Case 2 was a 73-year-old female. She was admitted because of heart failure (NYHA IV). As RVP wave indicated dip & platou at cardiac catheterization, she was diagnosed as constrictive pericarditis. ADA level in pleural effusion increased. So tuberculosis was suspected as etiology of constrictive pericarditis. In both cases, after pericardiectomy, heart failure improved to NYHA I. Results of pathological examination were tuberculous inflammation.

Aged↗
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↗
PubMed1993

Congenital plasminogen deficiency caused by a Ser572 to Pro mutation.

We used a polymerase chain reaction (PCR) strategy and restriction fragment polymorphism analysis to evaluate all 19 exons of the plasminogen (PLG) gene in a Japanese patient with congenital PLG deficiency and her family members. She presented with cerebral infarction. Sequence analysis following amplification of each exon and its flanking regions showed a single T to C transition in exon 14, which changed a Ser572 codon (TCC) to Pro572 codon (CCC). Since this mutation generates a new Fok I site, the Fok I digestion pattern of the PCR-amplified exon 14 fragments from each family member was analyzed. In all cases, the patterns were consistent with the activities and antigen levels of plasma PLG in those members. Furthermore, all PCR-amplified exon 14 fragments from 15 normal individuals were not restricted with Fok I endonuclease. We conclude that a T to C transition in exon 14 identified in the propositus is responsible for PLG deficiency inherited in this Japanese family with thrombotic episodes.

Adult↗
PubMed1993

Reduction of lipoprotein(a) by LDL-apheresis using a dextran sulfate cellulose column in patients with familial hypercholesterolemia.

Lipoprotein(a) (Lp(a)) was eliminated by LDL-apheresis using a dextran sulfate cellulose column in 3 homozygous and 10 heterozygous familial hypercholesterolemic patients. Immediately after LDL-apheresis by the LA-15 system (continuous LDL apheresis), there were significant reductions in Lp(a) concentrations (28.6 +/- 11.8 mg/dl (mean +/- S.E.) to 9.6 +/- 5.6 mg/dl (P < 0.01)), and in LDL-cholesterol concentrations (156 +/- 32 mg/dl to 48 +/- 18 mg/dl (P < 0.01)). Immediately following LDL-apheresis, Lp(a) and LDL-cholesterol were reduced by 67.4% +/- 11.6% and 68.3% +/- 11.8%, respectively. The removal of Lp(a) paralleled that of LDL-cholesterol. The reduced levels of Lp(a) nearly returned to baseline within 7 days. In 6 of the heterozygous FH patients the rates of recovery of LDL cholesterol and Lp(a) were calculated, according to Apstein's equation after discontinuing lipid altering drug treatment for 4 weeks. Mean constant k values of LDL cholesterol and Lp(a) were 0.354 (range: 0.136-0.752) and 0.427 (range 0.112-0.933), respectively. The average concentration during the 7 days following LDL-apheresis was calculated. Average reductions were 28% in LDL cholesterol and 18% in Lp(a). Pravastatin treatment, which continued for 4 weeks, significantly decreased LDL cholesterol (P < 0.01); however, before LDL-apheresis pravastatin treatment significantly increased Lp(a) levels (P < 0.05) in a small number (n = 6) of the FH patients, who had been regularly treated with LDL-apheresis. These results suggest that LDL-apheresis using the dextran sulfate cellulose column is an effective treatment to reduce levels of serum Lp(a) and LDL proportionally. This therapy may be of value in the prevention and regression of coronary artery disease in FH patients.

Adolescent↗
PubMed1993

Mutagenic activity of some platinum and palladium complexes.

The mutagenic properties of 16 platinum compounds were studied using Salmonella typhimurium TA98 and TA100. Eight of the compounds were considered direct mutagens, as their mutagenicity was not dependent on metabolic activation by liver extracts. Potent mutagenicity and high toxicity were exhibited by cis-Pt(NH3)2Br2, cis-Pt(NH3)2Cl2, Pt(C5H12N2)Cl2 and Pt(en)Cl2 for both bacterial strains. When distilled water was used as the carrier solvent, these compounds were strongly mutagenic and toxic, but much less so when dimethyl sulfoxide was the solvent.

Chlorine↗
PubMed1993

Tracheal reconstruction after lower tracheal resection using the inverted right bronchus--an experimental study.

An experimental study of tracheal reconstruction after lower tracheal resection using the inverted bronchus was performed in 8 dogs. After right upper lobectomy, the five cartilage rings of the lower trachea, ending three cartilage rings above the carina, was circumferentially resected; the right bronchus was transected just above the right second carina, the portion of the transected trachea above the carina was closed, and the right bronchus was inverted. The peripheral end of the upper trachea was anastomosed to the inverted right bronchus, and the intermediate bronchus was anastomosed to the lateral wall of the left bronchus. After completion of the airway reconstruction, the anastomotic site was wrapped with an omental flap. Although anastomotic complication were observed in two dogs, all the dogs survived the operation. Bronchoscopically and histopathologically, the findings for the inverted bronchus were almost normal three to four weeks after the operation. The clinical relevance of such a tracheal reconstruction is discussed.

Anastomosis, Surgical↗
PubMed1993

Modulation of noradrenaline release via activation of presynaptic beta-adrenoceptors in rabbits with adriamycin-induced cardiomyopathy.

We investigated the role of beta-adrenoceptors at postganglionic sympathetic nerve endings in noradrenaline release in rabbits with cardiomyopathic congestive heart failure produced by adriamycin (1 mg/kg, I.V., twice a week for 8 weeks). Plasma noradrenaline levels were measured before, 30 min after, and 60 min after the start of continuous intravenous administration of adrenaline (0.06 micrograms/kg/min) in adriamycin-treated and vehicle-treated rabbits in anesthetized condition and pithed condition with electrically stimulated sympathetic outflow (3 Hz, 1 ms square wave pulse, 90 V). In both the anesthetized and pithed conditions, adrenaline increased plasma noradrenaline levels in vehicle-treated rabbits. However, in the adriamycin-treated rabbits, adrenaline had no effect on the plasma noradrenaline level. Pretreatment with propranolol (0.2 mg/kg, bolus I.V. + 0.1 mg/kg/hr, continuous infusion) almost completely abolished the rise in plasma noradrenaline associated with adrenaline infusion in vehicle-treated rabbits. These results suggest that in rabbits with adriamycin-induced cardiomyopathy, the noradrenaline release from the sympathetic nerve endings via the activation of presynaptic beta-adrenoceptors is reduced. This might be due to down-regulation of presynaptic beta-adrenoceptors caused by the elevated plasma noradrenaline due to cardiac failure. However, other possibilities such as reduced affinity or impaired signal transduction cannot be excluded.

Animals↗
PubMed1993

Malignant histiocytosis with multiple skin lesions in a dog.

A 7-year-old male Yorkshire terrier was examined for multiple plaques and nodules on the skin. The clinical, cytological and histopathological features indicated a malignant histiocytosis. Cytoreductive chemotherapy produced moderate clinical improvement, but died at day 90 after the first admission. Pathological examination revealed the neoplastic histiocytes in the skin as well as in the myocardium and skeletal muscles.

Animals↗
PubMed1993

[Combined resection of the aortic wall in T4 lung cancer under the assistant devices].

Radical operation for T4 lung cancer is technically difficult. We report here 3 cases of T4N0M0 lung cancer involving aorta or left subclavian artery which was successfully operated on. We could carry out combined aortic resection more safely and speedy under the assistant devices, such as Anthrontube and Biomedicus Centrifugal Pump. Even T4 lung cancer having aortic invasion with N0 disease can be operated on and be expected long-term survival using these assistant devices.

Adenocarcinoma↗
PubMed1992

Type I congenital plasminogen deficiency is not a risk factor for thrombosis.

The risk of thrombosis in type I congenital plasminogen (PLG) deficiency has been suggested, but is still not confirmed. We studied 40 members of two unrelated families with this disease, and found that 21 were heterozygotes of type I congenital PLG deficiency. Three of them had thrombosis, but the other 18 had no thrombosis. The percentages of family members with no history of thrombosis up to a given age among subjects with type I congenital PLG deficiency and healthy controls were analyzed by the Kaplan-Meier method. No significant difference between the two groups was observed by the generalized Wilcoxon test (p = 0.23). These results suggest that there is no significant correlation between type I congenital PLG deficiency and thrombosis.

Adult↗
PubMed1992

In vivo-in vitro replicative DNA synthesis (RDS) test using perfused rat livers as an early prediction assay for nongenotoxic hepatocarcinogens: I. Establishment of a standard protocol.

To establish a standard protocol for an in vivo-in vitro hepatocyte replicative DNA synthesis (RDS) test using male F344 rats for screening nongenotoxic (the Ames-negative) hepatocarcinogens, experimental conditions were examined. After treatment with three model hepatocarcinogens, isolated hepatocytes showed highest RDS incidences when plated at a density of 5 x 10(4) cells/ml. Spontaneous RDS incidences in hepatocytes from rats aged 9 weeks or older showed a constant value. The use of hepatocytes from 9-week-old rats at the 5 x 10(4) cells/ml plating density was therefore determined as the standard. Based on the distribution of mean spontaneous RDS incidences over 105 additional experiments (0.4 +/- 0.18%, with SEM), an RDS incidence of over 1% was adopted as the criterion for a positive response in our rat liver RDS test.

Age Factors↗
PubMed1992

In vivo-in vitro replicative DNA synthesis (RDS) test using perfused rat livers as an early prediction assay for nongenotoxic hepatocarcinogens: II. Assessment of judgement criteria.

To better establish in vivo-in vitro hepatocyte replicative DNA synthesis (RDS) test using male F344 rats as a screening assay for nongenotoxic (the Ames-negative) hepatocarcinogens, judgement criteria were assessed after single-gavage treatment with seven model compounds. The profiles of RDS induction by the compounds were analysed in terms of both time-course and dose-dependence. Our data reveal that a value of 2% or more for RDS incidence should be judged as positive and that of less than 1% RDS incidence as negative using maximum tolerance dose (MTD) concentrations in time-course experiments at 15, 24, 39, 48 and 63 h. In the case of an incidence value between 1 and 2%, the finding of a clear dose-dependence was considered to justify the conclusion of a positive effect for 1/4 MTD, 1/2 MTD, MTD and 2 x MTD at a fixed time. The established judgement criteria are planned for introduction in detection of nongenotoxic hepatocarcinogens (the Ames-negative carcinogens) using the RDS test.

Animals↗