Biomedical subjects

S Urata

Publications and source records attributed to S Urata.

5 recordsLinked to original sources

PubMed2000

From amino acid landscape to protein landscape: analysis of genetic codes in terms of fitness landscape.

Assigning the values of a certain physicochemical property for individual amino acids to the corresponding codons, we can make an amino acid property "landscape" on a four valued three dimensional sequence space from a genetic code table. Eleven property landscapes made from the standard genetic code (SGC) were analyzed. The evaluation of correlation for each landscape is done by theta value, which represents the ratio of the mean slope (as an additive term) to the degree of roughness (as a nonadditive term). The theta-values for hydropathy indices, polarity, specific heat, and beta-sheet propensity were considerably large with respect to SGC. This implies that the additivity of the contribution from each letter holds for these properties. To clarify the meaning of the so-called mutational robustness of SGC, we next examined correlations between the amino acid property and the actual "site fitnesses" of a protein. The site fitnesses were derived from a set of binding preference scores of amino acid residues at every site in MHC class I molecule binding peptides (Udaka et al. in press). We found that the SGC's theta value for an amino acid property is correlated with the significance of the property in the protein function. Adaptive walk simulation on fitness (= affinity) landscapes in a base sequence space for these model peptides confirmed better evolvability due to the introduction of SGC.

Amino Acids↗

PubMed1998

Transient decrease in skin resistance response and level at the deh-chi stage caused by manual acupuncture.

Deh-chi is described as a kind of soreness, numbness, or heavy swelling in deep tissues during manual acupuncture. This finding is important in acupuncture therapy, although the mechanism of this phenomenon remains unclear. Skin resistance response (SRR) and skin resistance level (SRL) are expressed as a component of alternating current and direct current changes in electrodermal activity (EDA) respectively. In the present study, we recorded SRR and SRL, skin blood flow and perspiration simultaneously in an attempt to determine the relationship between skin sympathetic nerve activity and EDA at the deh-chi stage. We found that SRR, SRL and skin blood flow decrease, and that perspiration increases transiently at the deh-chi stage. Our findings indicate that manual acupuncture causes an increase in vasomotor and sudomotor activities, a decrease in skin blood flow, and increased perspiration. These SRR and SRL recordings may be taken as an indicator of deh-chi.

Acupuncture Points↗

PubMed1991

[An autopsy case of cardiomyopathy combined with nephrotic syndrome and pulmonary cytomegalic inclusion disease].

A 63-year-old male complained of palpitation and dyspnea. ECG showed paroxysmal supraventricular tachycardia. Echocardiogram revealed asymmetrical thickening of the cardiac septum, and by other clinico-pathological observations, nephrotic syndrome and colon adenoma were detected. For these diseases, steroid therapy and operation were performed, respectively. Ten months later, chest X-ray revealed diffuse abnormal shadow in the bilateral lung fields, and the patient expired due to respiratory distress syndrome. The patient's heart weighted 300g and showed extensive myofibril disarray in bilateral ventricles involving the septal region of the heart. Degeneration and atrophy of the atrioventricular node was seen. In the lungs, organizing pneumonia, old pleuritis, diffuse septal fibrosis and cytomegalovirus infection were demonstrated in the alveolar walls. Kidneys showed slightly sclelotic changes in glomeruli and edema-fibrosis in the interstitium. In this rare case, hypertrophic cardiomyopathy was combined with nephrotic syndrome due to glomerular change, and colon adenoma. The patient died of cytomegalovirus infection in the lungs. The histogenesis of myofibril disarray was discussed in these diseases.

Cardiomyopathy, Hypertrophic↗

PubMed1990

[A case of neonatal herpes simplex virus encephalitis with calcifications of thalamus and basal ganglia].

A male infant developed left-sided myoclonus associated with low grade fever at 21 days of age. The course of pregnancy and delivery had been uneventful. Birth weight was 2,240g at 38 weeks of gestation. Physical examination at 26 days of age revealed hyperirritability and incomplete Moro reflex. EEG showed periodic discharges originating in the right central region. Initial brain CT at 26 days of age showed no apparent abnormality. In lumbar CSF protein was 173 mg/dl, and nucleated cells 328/mm3 (polynuclear cells 6 and mononuclear cells 322). Cultures of CSF for bacteria and viruses were negative. Although, the serum titers of CF antibody to herpes simplex virus (HSV) were 1:4 to 1:8 during hospitalization and those in CSF were not increased significantly, ELISA titers for IgG and IgM in serum and CSF rose significantly. The diagnosis of HSV encephalitis was made at 41 days of age. His myoclonus was well controlled with phenobarbital and clonazepam. He was treated with acyclovir and CSF findings returned to normal. On 2nd brain CT (39 days of age), calcification at thalamus, basal ganglia and right frontal lobe, which is extremely rare CT findings for HSV encephalitis, was noticed. His DQ at discharge was about 90. It is emphasized that the early diagnosis of HSV encephalitis can be made by ELISA and serial brain CT examinations, and that HSV encephalitis should be considered when calcification of thalamus and basal ganglia are detected on brain CT.

Basal Ganglia Diseases↗

PubMed1989

Effect of deuterium oxide (D2O) on the IgE-mediated Ca2+ influx, arachidonic acid and histamine release in rat basophilic leukemia cells.

Deuterium oxide (D2O), which is known to stimulate microtubule aggregation, enhanced the IgE-mediated 45Ca2+ influx, (14C)-arachidonic acid and histamine release in rat basophilic leukemia cells (RBL-2H3) in the same dose-dependent manner (up to 90% (v/v]. We compared the interaction between D2O and a variety of groups of pharmacological agents. A microtubule depolymerizing agent, demecolcine, which inhibited the IgE-mediated (14C)-arachidonic acid and histamine release without affecting 45Ca2+ influx, was counteracted by 45% D2O. Taxol, a microtubule stabilizing agent, which had an inhibitory effect on the above three steps, was also reversed by 45% D2O. These results would support the previous data on the interaction between D2O and microtubules and would further suggest that the status of microtubule aggregation may be related to the secretory process. Calmodulin inhibitors (W-7, trifluoperazine) blocked the IgE-mediated 45Ca2+ influx, (14C)-arachidonic acid and histamine release in the same dose-dependent manner, but were counteracted by 45% D2O. In contrast, the effects of proteinase inhibitors (TPCK, TLCK), an adenylate cyclase inhibitor (ddAdo), a phosphodiesterase inhibitor (aminophylline), a phospholipid methylation inhibitor (DZA + Hcy) and microfilament blockers (cytochalasin B and D) were not counteracted by 45% D2O. These results would suggest that D2O may be associated with calmodulin directly or indirectly possibly through some relationship between calmodulin and microtubules.

Animals↗