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Biomedical subjects

K Tsuchiya

Publications and source records attributed to K Tsuchiya.

At least 379 records · Page 21Linked to original sources

[Alcoholic cerebellar degeneration with pyramidal sign--in relation to alcoholic myelopathy].

Two cases of alcoholic cerebellar degeneration with pyramidal sign were reported. Patient 1 with alcohol dependence syndrome was a 46-year-old woman. After the alcohol abuse of about eight years, she complained of gait disturbance. The gait disturbance progressively worsened in about two months and she could not ambulate freely by herself. Neurological examination revealed nystagmus, ataxic and spastic gait, slight weakness and spasticity of the lower extremities, hyperreflexia of the extremities, bilateral Babinski's signs, and incoordination of the lower extremities. Examination of liver function and serum B12 was normal. Cranial CT scan and MRI revealed atrophy of the cerebellar vermis and dorsal part of the cerebellum. Though neurological signs slightly improved after the admission to our hospital and the abstinence from alcohol abuse, ataxic gait and hyperreflexia of the extremities have continued. Patient 2 was a 58-year-old man. He was a heavy drinker, but was not a patient with alcohol dependence syndrome. After the heavy drinking of about 40 years, he complained of gait disturbance. The gait disturbance had progressively worsened in about four months. Neurological examination revealed ataxic gait, hyperreflexia of the lower extremities, and bilateral Babinski's signs. Laboratory examination revealed slight liver dysfunction with minimal GPT and moderate gamma-GTP elevation. Examination of serum B12 was normal. Cranial CT scan and MRI revealed atrophy of the cerebellar vermis. Though bilateral Babinski's signs disappeared after the abstinence from heavy drinking, ataxic gait and hyperreflexia of the lower extremities have continued. Alcoholic myelopathy without hepatic cirrhosis was rarely reported. In the relation of alcoholic cerebellar degeneration to alcoholic myelopathy, our cases are interesting and important.

Alcoholism↗

Indium-111-labeled leukocyte scintigraphy in a case of cutaneous sarcoidosis.

A 54-yr-old woman with cutaneous nodules showed accumulation of 67Ga- and 111In-labeled leukocytes in skin nodules, bilateral pulmonary hilar lymph nodes and the right upper mediastinum. Biopsy of the skin nodule proved epithelioid cell granuloma with moderate lymphocyte infiltration peripherally consistent with sarcoidosis. Sarcoidosis is a potential pitfall in labeled leukocyte imaging, which is performed for detecting a febrile focus.

Female↗

[Immunogenetic analysis of rheumatoid arthritis in the Japanese population].

To reveal immunogenetic factors involved in the pathogenesis of rheumatoid arthritis(RA), two hundreds and four unrelated Japanese patients with RA were typed for HLA by both serologic typing and DNA typing using polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSOP) method. Serologic HLA typing data showed that frequencies of HLA-A11, DR4, DR53, and DQ4 were increased and those of DR8, DR52, and DQ1 were decreased in the patient group. The HLA-DNA typing has defined more precisely the disease-associated HLA-class II alleles and revealed that DRB1*0405, DQA1*03, and DQB1*0401 were strongly associated with the disease susceptibility whereas DRB1*0803, DQA1*0103, and DQB1*0601 showed negative association with RA. Comparison of amino acid sequences of DRB1*0405 with other DRB1 alleles suggested that the risk for RA was closely associated with particular amino acid residues of DR beta chain, i. e. glycine residue at the 86th position in addition to the residues between 70th and 74th position. The significant decreased frequency of DRB1*0803 in the DRB1*0405 positive patient group suggests that DRB1*0803 may control resistance to RA as a dominant genetic trait. In addition, the observation that the frequency of DPB1*0201 was increased in the DRB1*0405 negative patient group may indicate that the disease susceptibility to RA is controlled by the HLA-DP region in the minority of the patients. The polymorphism of TAP2 gene and TCR genes showed no significant association with RA, suggesting that the contribution of these genes to the susceptibility is relatively small, if any.

Adult↗

DNA cleavage by hydroxyl radicals generated in a vanadyl ion-hydrogen peroxide system.

Vanadyl ion (+4 oxidation state) has been shown to be an effective agent for chemoprotection of cancers in animals. For understanding the mechanism, distribution of vanadium was studied. More vanadium was found to accumulate in the nuclei of the liver of rats when it was given as vanadyl sulfate than when it was given as sodium vanadate (+5 oxidation state). The reactivity of vanadyl ion with DNA was investigated by the DNA cleavage technique and the reaction mechanism by ESR spectroscopy. Incubation of double-strand DNA with vanadyl ion and hydrogen peroxide resulted in marked concentration- and pH-dependent DNA cleavage. Studies by the ESR spin-trap method demonstrated that hydroxyl radicals are generated during the reactions of vanadyl ion with hydrogen peroxide. Thus the antineoplastic action of vanadyl ion is proposed to be due to DNA cleavage by hydroxyl radicals generated in the cells.

Animals↗

ATP is a coupling modulator of parallel Na,K-ATPase-K-channel activity in the renal proximal tubule.

A fundamental and essential property of nearly all salt-transporting epithelia is the tight parallel coupling between the magnitude of the K-conductive pathway at the basolateral membrane and the activity of the Na,K-dependent ATPase (Na,K-ATPase). In the present study, we demonstrate that the coupling response in the renal proximal tubule is governed, at least in part, through the interaction between ATP-sensitive K channels and Na,K-ATPase-mediated changes in intracellular ATP levels. First, we identified a K-selective channel at the basolateral membrane, which is inhibited by the cytosolic addition of ATP. Second, conventional microelectrode analysis in the isolated perfused proximal straight tubule revealed that these channels are the major determinant of the macroscopic K conductance so that ATP-mediated changes in the open probability of the K channel could alter the extent of K recycling. Indeed, the increase in the macroscopic K conductance upon stimulation of transcellular Na transport and pump activity was found to be paralleled by a decrease in intracellular ATP. Finally, a causal link between parallel Na,K-ATPase-K-channel activity and ATP was established by the finding that intracellular ATP loading uncoupled the response. With our recent observations that similar ATP-sensitive K channels are expressed abundantly in other epithelia, we postulate that ATP may act as a universal coupling modulator of parallel Na,K-ATPase-K-channel activity.

Adenosine Triphosphate↗

The discovery of the causal agent of Minamata disease.

After the outbreak of an epidemic of a strange disease characterized by severe neurological signs in the small Japanese town of Minamata, a number of scientists in different disciplines were required to identify the causal agent. An account is given of the three-year program, with its disappointments and frustrations as a result of the limitations of knowledge of ecological principles and the absence of adequate techniques for detection and measurement. The lessons that have been learned on how toxic compounds can accumulate and concentrate in food chains are described as are the ecological contributions of environmentally safe waste disposal techniques. This article is based on the recollections of Dr. Shoji Kitamura, who contributed greatly to the discovery of the causative agent of Minamata disease.

Animals↗

High level expression of the synthetic human lysozyme gene in Aspergillus oryzae.

Aspergillus oryzae was transformed with a synthetic gene consisting of a chicken lysozyme signal sequence and a mature human lysozyme (HLY) sequence. The transformants secreted active HLY (about 1.2 mg/l) when the HLY gene was expressed under the control of the Taka-amylase A gene (amyB) promoter. Western blot analysis suggested that the secreted protein was immunoreactive with anti-human lysozyme antibody and the signal peptide was correctly cleavaged off in the A. oryzae transformants. The transcriptional level of the HLY gene was investigated by Northern blot analysis using a probe that was equivalently specific to both the HLY gene and the amyB gene. The HLY gene was expressed at a higher level compared with the amyB gene because of its multi-copy integration. The efficient transcription of the HLY gene suggested that A. oryzae is a promising host for production of heterologous proteins from higher eukaryotes.

Amylases↗

Contrast-enhanced magnetic resonance imaging of sub- and epidural empyemas.

Contrast-enhanced magnetic resonance images (MRI) of three patients with subdural (SDE) and two with epidural empyemas (EDE) were reviewed. In each case, the capsule of the lesion demonstrated enhancement, and distinction between capsule and contents was obvious on contrast-enhanced images. In SDE, contrast-enhanced images clearly depicted thickening of the neighbouring dura mater and a co-existent brain abscess. In EDE, part of the displaced dura mater did not enhance, which facilitated differentiation from SDE. Contrast-enhanced MRI was thus of value in diagnosis.

Adolescent↗

Millardia meltada, a new host for Acanthocheilonema viteae and a simple technique for separation of microfilariae from peripheral blood.

Millardia meltada were infected with Acanthocheilonema viteae and examined for their susceptibility. The morbidity of infected M. meltada was low compared with that of jirds. On day 47 post-infection (p.i.), 13 of 14 M. meltada developed microfilaremia. Male M. meltada then showed gradually increasing microfilaremia with a peak level of 7000 per 30 microliters blood at week 20 p.i., which was much higher than that (3000) of male jirds. In contrast, microfilarial densities of female M. meltada were markedly low with a peak level of 200 during weeks 10-12 p.i. A simple centrifugation technique with Lympholyte-M was devised for microfilarial separation from the peripheral blood of infected M. meltada and yielded approximately 17 x 10(5) viable microfilariae from 1 ml of blood. This method also makes it possible to collect microfilariae from the same individuals repeatedly. M. meltada, coupled with this microfilarial separation technique, serves as a useful animal model for microfilarial studies of A. viteae.

Animals↗

Intravascular foreign bodies: loop-snare retrieval system with a three-lumen catheter.

A foreign body retrieval system composed of a three-lumen catheter, a guide wire, and a wire loop nearly perpendicular to the axis of the catheter was used to retrieve catheter fragments located in the inferior vena cava in two patients and in the superior vena cava in one patient. Fragments were looped within 1 minute of catheterization and were retrieved without complication. Catheter fragments placed in the pulmonary artery of one dog were also successfully retrieved.

Animals↗

Guide-wire-directed detachable balloon: clinical application in treatment of varicoceles.

Wire-directed detachable balloons were used in embolization treatment of varicoceles in six patients. Advancement of the balloon over a guide wire allowed easy embolization of the internal spermatic vein at the level of the inguinal ring. Additional detachable balloons were used to occlude the collateral vessels to the varicocele. This method proved highly effective in embolization of tortuous veins and in placement of multiple balloons.

Adolescent↗

Further observations on serial serum immunoreactive inhibin levels in the luteal phase and early gestation after ovarian stimulation for in vitro fertilization and embryo transfer.

Serum immunoreactive inhibin of the luteal phase was measured by radioimmunoassay in 71 patients in vitro fertilization and embryo transfer (IVF-ET). The correlation between the pregnancy outcome and the serial inhibin pattern from the luteal phase to early gestation was studied. In nonconception cycles (n = 35), serum inhibin concentration rose and reached a peak level around 5 or 6 days after oocyte pick-up (OPU), then fell to the level of the early follicular phase. In conception cycles (n = 22), serum inhibin levels rose again 10-15 days after OPU. Serum inhibin levels were significantly higher from 10 days after OPU in multiple pregnancy (n = 5) than in single pregnancy (n = 17). In viable single pregnancy (n = 17), serum inhibin levels were significantly higher than in non-viable pregnancy (n = 14) from 15 days after OPU. Serum inhibin levels in early gestation correlated well with the pregnancy outcome of IVF-ET. These data suggest that inhibin is an important factor for the diagnosis of pregnancy outcome.

Abortion, Spontaneous↗

Indonesian medicinal plants. II. Chemical structures of Pongapinones A and B, two new phenylpropanoids from the bark of Pongamia pinnata (Papilionaceae).

Two new phenylpropanoids named pongapinone A (1) and pongapinone B (2) were isolated from the bark of Pongamia pinnata (Papilionaceae), an Indonesian medicinal plant, and their chemical structures have been elucidated on the basis of their physicochemical properties. Pongapinone A (1) was found to inhibit interleukin-1 production.

Chromones↗

Deletion analysis of the Taka-amylase A gene promoter using a homologous transformation system in Aspergillus oryzae.

The Taka-amylase A gene (amyB) of Aspergillus oryzae is induced by starch or maltose. The molecular mechanism of the induction was investigated using a fusion of the amyB promoter and the Escherichia coli uidA gene encoding beta-glucuronidase (GUS). To identify the region responsible for high-level expression and regulation within the amyB promoter, a series of deletion promoters was constructed and introduced into the A. oryzae met locus by homologous recombination. Deletion of the region between -377 to -290 (the number indicates the distance in base pairs from the translation initiation point (+1) to the deletion end point) significantly reduced of the GUS activity, but slight reduction of the GUS activity was observed in deletions up to -377. Northern blot analysis showed that reduction of the GUS activity depended upon the expression level of the GUS gene. The region between -377 to -290 is suggested to include the sequence required directly for high-level expression and regulation of the amyB gene.

Aspergillus oryzae↗

Purification and characterization of a thermostable alkaline protease from alkalophilic Thermoactinomyces sp. HS682.

Protease secreted into the culture medium by alkalophilic Thermoactinomyces sp. HS682 was purified to an electrophoretically homogeneous state through only two chromatographies using Butyl-Toyopearl 650M and SP-Toyopearl 650S columns. The purified enzyme has an apparent relative molecular mass of 25,000 according to gel filtration on a Sephadex G-75 column and SDS-PAGE and an isoelectric point above 11.0. Its proteolytic activity was inhibited by active-site inhibitors of serine protease, DFP and PMSF, and metal ions, Cu2+ and Hg2+. The enzyme was stable toward some detergents, sodium perborate, sodium triphosphate, sodium-n-dodecylbenzenesulfonate, and sodium dodecyl sulfate, at a concentration of 0.1% and pH 11.5 and 37 degrees C for 60 min. The optimum pH was pH 11.5-13.0 at 37 degrees C and the optimum temperature was 70 degrees C at pH 11.5. Calcium divalent cation raised the pH and heat stabilities of the enzyme. In the presence of 5 mM CaCl2, it showed maximum proteolytic activity at 80 degrees C and stability from pH 4-12.5 at 60 degrees C and below 75 degrees C at pH 11.5. The stabilization by Ca2+ was observed in secondary conformation deduced from the circular dichroic spectrum of the enzyme. The protease hydrolyzed the ester bond of benzoyl leucine ester well. The amino acid terminal sequence of the enzyme showed high homology with those of microbial serine protease, although alanine of the NH2-terminal amino acid was deleted.

Amino Acid Sequence↗