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Biomedical subjects

Y Takeuchi

Publications and source records attributed to Y Takeuchi.

At least 775 records · Page 43Linked to original sources
PubMed1989

Frequent lack of antibodies against human T-cell leukemia virus type I gag proteins p24 or p19 in sera of patients with adult T-cell leukemia.

Specificities of antibodies against human T-cell leukemia virus type I (HTLV-I) in sera of 27 patients with adult T-cell leukemia (ATL) were studied. All sera were positive for HTLV-I antigens by immunofluorescence assay using cells expressing HTLV-I antigens; sera from five ATL patients, however, did not react or hardly reacted with p19 or p24 gag proteins of HTLV-I upon immunoprecipitation assay. Therefore, the relationships among antibody specificities against HTLV-I, the proviral structures of HTLV-I genomes in leukemic cells, and the expression of viral antigens by leukemic cells after cultivation in vitro for a few days were examined. Analyses of the genomic structures of the proviruses revealed deletions in at least seven cases. However, we could not detect deletions in the proviral genomes of four out of the five ATL patients who lacked antibodies against gag proteins. Furthermore, expression of p19 and p24 was detected in these patients' peripheral blood lymphocytes (PBL) cultured in vitro for a few days. Thus, some ATL patients could not or could hardly raise antibodies against gag proteins, although they harbored complete HTLV-I genomes and their PBL expressed gag proteins in vitro. All patients harboring deleted proviruses, so far tested, raised antibodies not only against viral proteins that should be encoded by the integrated proviruses, but also against viral proteins that should be encoded by the deleted regions. Antibodies against viral proteins were detected also in sera of ATL patients whose PBL did not express viral proteins after in vitro cultivation. Specificities of antibodies against viral proteins in ATL patients could not be predicted by the structures of proviruses in leukemic cells or by expression of viral proteins in vitro. Immune responses to HTLV-I antigens were weak or lost in some ATL patients.

Gene Products, gag↗
PubMed1989

Further confirmation of serotonin reduction in the neostriatum during hyperthermia-induced convulsions: a quantitative immunohistochemical study.

Changes occurring in serotonin neurons during hyperthermia and hyperthermia-induced convulsions were examined by quantitative immunohistochemistry. A marked increase in serotonin immunoreactivity was observed at the rostral and intermediate levels of the neostriatum of mice kept at high temperatures with no convulsions, and a significant reduction in serotonin immunoreactivity was verified throughout the neostriatum of mice which had hyperthermia-induced seizures. These results suggest that serotonin neurons change significantly during thermal stress and seizures, and that regional analysis is essential for an understanding of the role of serotonin neurons.

Animals↗
PubMed1989

Diffusion-mediated persistence in two-species competition Lotka-Volterra model.

We consider a system composed of two Lotka-Volterra patches connected by diffusion. Each patch has two competitors. Conditions for persistence of the system are given. It is proved that the system can be made persistent under appropriate diffusion coefficients ensuring the instability of boundary equilibria, even if each species is not persistent within each patch. The choice of the coefficients depends closely on the patch dynamics without diffusion.

Animals↗
PubMed1989

Population diffusion in a two-patch environment.

A model of a single-species population diffusing in a two-patch environment is proposed. It is shown that there exists a positive, monotonic, continuous steady-state solution with continuous flux, in the cases of both reservoir and no-flux boundary conditions, that is asymptotically stable. In the case of patches with equal carrying capacities, it is shown that the uniform steady state is globally asymptotically stable.

Ecology↗
PubMed1989

Administration of human leukocyte interferon to patients with subacute sclerosing panencephalitis.

Between 1979 and 1982, fifteen patients with SSPE were treated with human leukocyte interferon (HuIFN-alpha). They were administered interferon (IFN) in doses ranging from 25 x 10(6) IU to 126 x 10(6) IU by various routes in regimens that ranged for 20 days to 14 months. In 3 of the 5 cases with rapid deterioration, HuIFN-alpha did not alter the course of the disease; however, 6 cases with mild progression showed various degrees of clinical improvement during the IFN therapy. In 3 of the 4 cases in remission, HuIFN-alpha caused no significant changes in clinical courses. No severe adverse reactions were seen during IFN administration. These results suggest that HuIFN-alpha has a potentially beneficial effect on the course of SSPE.

Adolescent↗
PubMed1989

Synthesis and antitumor activity of fused tetracyclic quinoline derivatives. 1.

Several fused tri- and tetracyclic quinolines (I and II) with [2-methoxy-4-[(methylsulfonyl)amino]phenyl]amino or [3-(N,N-dimethylamino)propyl]amino side chains were prepared, and their DNA intercalative properties, KB cytotoxicity, antitumor activity (P388 leukemia), and ability to induce topoisomerase II dependent DNA cleavage were investigated. Some compounds having both intercalative ability and KB cytotoxicity were found to be inactive in vivo. However, a positive correlation was seen between the ability to induce topoisomerase II dependent DNA cleavage and antitumor activity in vivo. The indeno- (13a), benzofuro- (21a), and benzothieno- (22a) quinoline derivatives exhibited potent antitumor activities in vitro and in vivo, comparable to those of m-AMSA. They also intercalate DNA and induce topoisomerase II dependent DNA cleavage. Extended screening of 13a showed it to be active against solid tumors such as M5076 sarcoma, B16 melanoma, and colon 38 carcinoma.

Animals↗
PubMed1989

Dihydropyrimidines: novel calcium antagonists with potent and long-lasting vasodilative and antihypertensive activity.

The novel calcium antagonists 3-N-substituted-3,4-dihydropyrimidines 1 and 9 and 3-N-substituted-dihydro-pyrimidin-2(1H)-ones 8 were regioselectively synthesized in good yields. Compounds 1 [especially 1s [R1 = (CH2)2N(benzyl)(2-naphthylmethyl), R2 = i-Pr, X = 0-NO2] and 1t [R1 = (CH2)2N(benzyl)(3,4-dichlorobenzyl), R2 = i-Pr, X = 0-NO2]] exhibited not only more potent and longer lasting vasodilative action but also a hypotensive activity with slow onset as compared with dihydropyridines. Moreover, some dihydropyrimidines [1q [R1 = (CH2)2N(benzyl)(3-phenylpropyl), R2 = CH2(cyclopropyl), X = 0-NO2], 1s, and 1t] were weaker in blocking atrioventricular conduction in anesthetized open-chest dogs and less toxic than the dihydropyridines.

Animals↗
PubMed1989

Complement C6 and C7 polymorphisms in Japanese patients with chronic glomerulonephritis.

C6 and C7 types were studied in 158 Japanese patients with different types of chronic glomerulonephritis: 75 patients with IgA nephropathy (IgA-N); 49 patients with idiopathic membranous nephropathy (IMN), and 34 patients with minimal-change nephrotic syndrome (MCNS). There were significant differences in the C6 and C7 allele and phenotype frequencies between the patient groups and controls. A strong association was found between IgA-N and C7 5 phenotype (p less than 0.001, RR = 12.71), and between MCNS and C7 5 phenotype (p less than 0.001, RR = 14.20). A significant association between MCNS and C6 B2 phenotype (p less than 0.05, RR = 2.42) was also found. In the IMN patient group, a significant association with C7 4 phenotype (p less than 0.05, RR = 2.42) was observed. Thus, C6 and C7 phenotypes may be causative factors in the development of chronic glomerulonephritis.

Complement C6↗
PubMed1989

Influence of alpha-chloralose on muscle relaxant effect of chlorzoxazone in rats and pharmacodynamic analysis.

The Pharmacological response intensity of chlorzoxazone (CZX) was measured by the crossed extensor reflex (CER) method in anesthetized rats. The appropriate dose of alpha-chloralose (ACH) was examined to bring about a quantitative effect of CZX. The pharmacodynamics of CZX was also characterized in the anesthetized rats at three different doses of CZX. When rats were anesthetized with ACH at three different doses (80, 110, and 150 mg/kg i.p.), the CER response caused by CZX at the doses of 25, 50, and 75 mg/kg p.o. was depressed dose-dependently. Among these three different doses of ACH, 80 and 110 mg/kg gave similar results in describing the pharmacological response induced by CZX with time, whereas a dose of 150 mg/kg of ACH elicited a stronger and longer CZX response than the other two doses. The area under the intensity-time curve also showed the same tendency. These findings suggested that the dose size ranging from 80 to 110 mg/kg of ACH for surgical anesthesia was appropriate to evaluate the quantitative pharmacological response of CZX. Pharmacodynamic analysis offered the results that the dose-normalized biophase levels of CZX were coincident with each other when CZX was given at three different doses under ACH anesthesia at the dose of 80 mg/kg. This suggested that the disposition of CZX in rats obeyed linear kinetics and the theoretical values of CZX-induced response would be predictable. This implied that pharmacological response intensity of CZX was reasonably related to the relative biophase CZX level via Hill's equation.

Animals↗
PubMed1989

[Method for simultaneous determination of six metabolites of toluene, xylene and ethylbenzene, and its application to exposure monitoring of workers in a printing factory with gravure machines].

For the biological monitoring of exposure to solvent composed of toluene, xylene, and ethylbenzene used in a printing factory with gravure machines, we developed a HPLC method for the simultaneous determination of urinary metabolites of this solvent, i.e. hippuric acid, o-, m-, and p-methylhippuric acid, mandelic acid and phenylglyoxylic acid. Except for phenylglyoxylic acid, urinary concentrations of the metabolites determined by the present method correlated well with the air concentrations of the respective solvent components. Hence the present method is useful in monitoring solvent exposure. In 91 workers of the printing factory and 53 control subjects, we also determined the concentrations of some phenolic metabolites and confirmed that o-cresol is a useful indicator for monitoring toluene exposure.

Benzene Derivatives↗
PubMed1989

Postoperative core-temperature rhythm of patients who underwent cardiac surgery.

Core-temperature rhythms of 16 patients who underwent cardiac surgery were studied and tow types of rhythm pattern were recognized. One showed a non-stationary part in the rhythm whereas the other did not. The non-stationary part of the rhythm was thought to be an expression of the disturbance caused by surgical intervention. Patients who suffered from 'ICU syndrome' showed a low-amplitude rhythm.

Adult↗
PubMed1989

[Clinical evaluation of perioperative myocardial infarction as a complication of valve replacement].

Perioperative myocardial infarction (PMI) is a well-known complication of coronary artery surgery, but rarely encountered in valvular surgery. We have experienced 6 cases of valve replacement with PMI, using blood cardioplegia since 1979. Those patients (5 men, one woman; mean age 47 +/- 8 years) had no previous angina, and preoperative CAG revealed no significant stenosis. Three patients were reoperative cases. A diagnosis of PMI was established by the following criteria; an abnormal increase in maxCPK-MB (greater than 150 IU/l), new Q waves at ECG, positive 99mTc-PYP scan (grade 3-4). The area of PMI was inferior in 4 patients, posterior in one, and anterior infarction was seen in only one case. Three cases required IABP, but all 6 cases showed good exercise capacity by Treadmill exercise test in late stage. Several factors are thought to be the cause of PMI at valvular surgery; such as coronary air embolism, perioperative coronary spasm, inappropriate topical hypothermia, etc. Prognosis is not necessarily poor, however much attention should be paid to prevent PMI in valve replacement.

Adult↗
PubMed1989

[A case of adenomatoid mesothelioma of the pleura].

A case of adenomatoid mesothelioma of the pleura was presented. The patient was a 69-year-old woman with diabetes mellitus. She was admitted to our hospital because of a chest roentgenographic abnormality, which was pointed out during her clinical course. Chest X-ray-film on admission revealed a semicircular lesion located in the left lower lung field. The physical examination and laboratory data showed no abnormalities. Left lower lobectomy was performed. The tumor was approximately, 3.0 x 3.0 x 3.0 cm, elastic soft, encapsulated, and originated from the pulmonary pleura. The histological findings of the tumor showed benign epithelial localized pleural mesothelioma. However histologically, the tumor tissue was not like the usual epithelial type. That is, most cells which had intracellular vacuoles, were similar to signet ring cell. The tumor was diagnosed as adenomatoid mesothelioma of the pleura.

Aged↗