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Biomedical subjects

Y Shiina

Publications and source records attributed to Y Shiina.

At least 37 records · Page 2Linked to original sources
PubMed1995

The tetracycline efflux protein encoded by the tet(K) gene from Staphylococcus aureus is a metal-tetracycline/H+ antiporter.

The tet(K) gene from Staphylococcus aureus was highly expressed in Escherichia coli by an alteration of its initiation codon from TTG to ATG and its ribosome-binding sequence from GAGG to GGAGG [Noguchi, N. et al. (1994) Biol. Pharm. Bull. 17, 352-355]. The inverted membrane vesicles prepared from the tet(K)-expressing cells showed respiration-dependent [3H]tetracycline transport comparable to the vesicles from the tet(B)-expressing cells. The affinity of Tet(K) vesicles to tetracycline was the same as that of Tet(B) vesicles, whereas the former Vmax value was about 60% of the latter one. Contrary to Tet(B) vesicles, Tet(K) vesicles showed no significant minocycline uptake, which was consistent with the low minocycline resistance of the Tet(K)-producing cells. The tetracycline transport mediated by Tet(K) vesicles was coupled with proton transport and the translocation of 60Co2+ ions as well as in Tet(B) vesicles. This observation indicates that the class K tetracycline resistance determinant from Gram-positive bacteria also encodes a metal-tetracycline/H+ antiporter that is functionally similar to that encoded by tet(B), although there is a considerable difference in the primary sequences and the putative topologies of these Tet proteins.

Antiporters↗
PubMed1995

Alterations of sympathovagal balance in patients with hypertrophic and dilated cardiomyopathies assessed by spectral analysis of RR interval variability.

Spectral analysis of RR interval variability was performed in 35 ambulatory patients with early hypertrophic cardiomyopathy (HCMa, NYHA class I), 21 hospitalized patients with advanced hypertrophic cardiomyopathy (HCMh, NYHA class II or III), and 18 hospitalized patients with dilated cardiomyopathy (DCMh, NYHA class I, II or III). Twenty-nine ambulatory subjects (COTa) and 20 hospitalized volunteers (COTh) served as normal controls. The RR interval standard deviation (SD), the high-frequency power (HF: 0.15-0.40 Hz) corrected by the mean RR interval (CCVHF) and the normalized unit of the HF power (NUHF) served as markers of vagal modulation. Low-frequency power (LF: 0.04-0.15 Hz) corrected by the mean RR interval (CCVLF) and the normalized unit of LF power (NULF) were markers of sympathetic modulation. The LF/HF ratio was an index of sympathovagal balance. There was no significant difference in the SD, CCVHF, NUHF, CCVLF, NULF or the LF/HF ratio between the HCMa and COTa groups. At night, the SD was lower in the HCMh group relative to the COTh group (P < 0.01). The HCMh group demonstrated lower CCVHF and NUHF values (P < 0.01), higher NULF values (P < 0.01) and higher LF/HF ratios (P < 0.05) at night relative to the COTh group. Two patients who later died suddenly in the HCMh group had markedly reduced CCVHF values (0.2-0.8%) relative to the survivors in the group (mean +/- SD in the morning, afternoon and night, 1.07 +/- 0.43%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[The validity and reliability of a Japanese version of Arthritis Impact Measurement Scales in patients with rheumatoid arthritis].

A Japanese version of Arthritis Impact Measurement Scales (Japanese-AIMS) was developed after the original AIMS Version 2 (AIMS 2). We then conducted a Quality of Life measurement of 691 patients with Rheumatoid Arthritis (RA) with this newly developed questionnaire. Based on the data collected, the validity and reliability of the Japanese-AIMS was examined. The validity of the Japanese-AIMS, which was assessed by the examination of internal consistency among items and through factor analysis, was almost comparable with that of the original AIMS 2. QOL scales were also validated using internal standards based on the subject's responses to other items in the questionnaire. The test-retest reliability, which was the correlation of scale scores between two tests administered 4-5 weeks apart, was slightly lower than the original one. We conclude that the validity and reliability of the Japanese AIMS were comparable with those of the original one, though there could be possibly improved by the minor revision of phrasing. The large scale QOL measurement study with RA patients is under way, using the Japanese-AIMS with minor revision.

Activities of Daily Living↗
PubMed1995

[Quality of life, subjective health status and health and life satisfaction in rheumatoid arthritis].

A Japanese version of Arthritis Impact Measurement Scales (AIMS) was developed after the original AIMS Version 2 and utilized for Quality of Life (QOL) measurement in 691 patients with Rheumatoid Arthritis (RA). Various medical (physical and laboratory) examinations, which are widely used in the clinical settings for the assessment of RA activity and severity, were also performed by physicians. Interrelationships between QOL, patient subjective health status, and health and life satisfaction were analyzed with the following results: 1: The effect of QOL impairment by RA upon patients' subjective health rating and health satisfaction were not constant over the range of severity of disease status. Pain was found to lower overall subjective health and health satisfaction regardless of RA class. On the other hand, while the deterioration of mobility aspects of QOL had negative effects upon patients' subjective health status and satisfaction among less-disabled RA patients, any of physical aspects of QOL, including the degree of mobility impairment, showed no significant association with patients' subjective health status and satisfaction in the more disabled. 2: Psychological aspects of QOL (mood and tension) had significant associations with patients' subjective health status and satisfaction. In the less severe group, mood impairment had a significant effect on subjective health and satisfaction, while in the more severe group tension showed a significant association. It was indicated that management of psychological aspects of QOL is important in RA patients to improve and advance their subjective health status and satisfaction. 3: Although social aspects of QOL, i.e. social support, social life and job status, showed no significant relationship to subjective health rating and health satisfaction, those with less disease severity who lacked social support and who had a jobless state were likely to have lower disease acceptance and life satisfaction, while those with more severe disease who had less social interaction manifested lower life satisfaction. These results suggested that social aspects of QOL, while not directly associated with subjective health rating, could be important factors affecting disease acceptance and life satisfaction.

Adult↗
PubMed1995

[A case of failure of mitroflow pericardial valve with severe hemolytic anemia].

A 49-year-old woman who underwent mitral valve replacement with 29 mm Mitroflow pericardial valve in 1985 started to have severe hematuria, anemia and icterus around May 1994. She was diagnosed to have mitral regurgitation with hemolytic anemia due to structural deterioration of the prosthetic valve. She underwent replacement of the prosthetic valve with 29 mm St. Jude medical mechanical valve, which alleviated the symptoms remarkably. The explanted valve showed an extensive cuspal tear and prolapse close to the commissure and poor endothelialization of the inflow surface of the frame. In our experience the rate of structural deterioration of the Mitroflow valve is so high that we discontinued using this bioprosthesis.

Anemia, Hemolytic↗
PubMed1994

Regional sympathetic denervation detected by iodine 123 metaiodobenzylguanidine in non-Q-wave myocardial infarction and unstable angina.

Previous studies have revealed that the sympathetic nervous system is more vulnerable to ischemia than the myocardium itself. Thus our study was undertaken to detect denervated myocardium in non-Q-wave myocardial infarction (MI) and unstable angina with iodine 123 metaiodobenzylguanidine (123I-MIBG), which can delineate myocardial sympathetic innervation. Eight patients with non-Q-wave MI and 12 with unstable angina were studied. Sequential 123I-MIBG and thallium-201 chloride (201TlCl) imaging and single-photon emission computed tomography (SPECT) were performed at rest 24 +/- 12 days after the last ischemic attack. Myocardial perfusion defect was not detected by 201TlCl in 4 of 8 patients with non-Q-wave MI, whereas 123I-MIBG SPECT imaging revealed defects corresponding to myocardial ischemic areas predicted by coronary angiography in all 8 patients. 123I-MIBG imaging revealed defects in 7 of 12 patients with unstable angina corresponding to coronary angiographic findings, whereas no myocardial perfusion defect was detected by 201TlCl imaging in any of them. In conclusion, 123I-MIBG SPECT is a sensitive method for detecting myocardium exposed to transient ischemia that cannot be detected by 201TlCl imaging.

3-Iodobenzylguanidine↗
PubMed1994

Study on the castability of Co-Cr alloy for cast plates. Part 4. Effects of sectional area, number of sprues and alloy components on castability.

Co-Cr alloy is used more frequently than Ni-Cr alloy as a nonprecious alloy for cast plates in Japan. Titanium with good biocompatibility has often been contained in the composition of this Co-Cr alloy. However, since the melting temperature of Co-Cr alloy is very high, about 1300 degrees C, and it oxidizes easily, a vacuum-pressure casting machine capable of melting this alloy in a reduced atmosphere has recently been developed. In this study, using the vacuum-pressure casting machine, the possible effects of sectional area and the number of sprues attached to the cast plate wax pattern, as well as the alloy components, on the castability of three kinds of Co-Cr alloy containing titanium were examined. It was found that all of these parameters had significant effects on Co-Cr alloy castability.

Chromium Alloys↗
PubMed1993

Immunological detection of F1-ATPase gamma-subunit in rat liver peroxisomes.

The gamma-subunit of F1-ATPase was detected in highly purified rat liver peroxisomes by immunoblot analysis using an antiserum against purified mitochondrial F1-ATPase. Other subunits of F1-ATPase such as alpha, beta and delta were not detected in the peroxisomes. The polypeptide corresponding to the gamma-subunit in peroxisomes was also recognized by affinity purified antibody against F1-ATPase gamma-subunit. The amount of gamma-subunit in liver homogenate increased in parallel with proliferation of peroxisomes after administration of clofibrate in rats, whereas the amounts of alpha, beta and delta-subunits were not increased. These results suggest that the gamma-subunit of F1-ATPase is a constituent of peroxisomes in rat liver.

Animals↗
PubMed1993

Role of the extracellular Ca2+ on the intracellular Ca2+ changes in fertilized and activated mouse oocytes.

Changes in intracellular calcium concentration ([Ca2+]i) in fertilized mouse oocytes were measured using the calcium-sensitive dye, fura-2. After fertilization, an initial long-lasting [Ca2+]i increase was followed by a periodic [Ca2+]i increase. The periodic increase in [Ca2+]i persisted for 1 to 3 h and all fertilized oocytes extruded the second polar body within 4 h. The mean interval of periodic [Ca2+]i increase was 470 +/- 180 s (mean +/- SD). The frequency of the periodic [Ca2+]i increase depended on the extracellular calcium concentration. Verapamil and nifedipine inhibited the periodic [Ca2+]i increase. Sixty-five per cent of tested cells extruded the second polar body within 90 min of exposure to 7% ethanol. In these activated oocytes, the long-lasting [Ca2+]i increase was observed. However, no cells showed a repetitive increase in [Ca2+]i. Both release of calcium from intracellular stores and influx of extracellular calcium contribute to the increase in [Ca2+]i induced by ethanol. We conclude that the extrusion of the second polar body requires an increase in [Ca2+]i above a certain threshold level and the mobilization of calcium of both the intracellular and extracellular space in mouse oocytes.

Animals↗
PubMed1993

Effects of pravastatin on lipid transfer protein and lecithin cholesterol acyltransferase in heterozygous familial hypercholesterolemia.

The effects of HMG CoA reductase inhibitor PRAVASTATIN on plasma lipoprotein levels, lipid transfer protein (LTP) activity and lecithin cholesterol acyltransferase (LCAT) activity were investigated in 20 patients with heterozygous familial hypercholesterolemia. Plasma total cholesterol decreased from 299.2 +/- 45.2 to 245.9 +/- 45.1 (mean +/- SD in mg/dl) (p < 0.0001), low density lipoprotein (LDL) cholesterol from 221.1 +/- 47.6 to 164.9 +/- 48.1 (p < 0.0001) and LDL-triglycerides from 38.0 +/- 10.2 to 30.2 +/- 8.8 (p < 0.0001). High density lipoprotein (HDL) cholesterol increased from 60.1 +/- 13.9 to 63.1 +/- 17.0 (p = 0.0264). The HDL-cholesterol: HDL-triglycerides ratio increased from 3.91 +/- 1.14 to 4.91 +/- 1.65 (p = 0.0029). Lipid transfer protein (LTP) activity (as % of transferred cholesteryl ester (CE)) decreased from 4.68 +/- 2.47 to 3.70 +/- 2.31 (p = 0.0024) and LCAT activity decreased from 113.1 +/- 29.9 (U/L) to 97.0 +/- 22.7. There was a negative correlation between LTP/LCAT ratio and HDL-C levels. These results suggested that the changes in plasma HDL-cholesterol concentrations during treatment with pravastatin may be related to the decreases in LTP and LCAT activity due to this drug.

Adult↗
PubMed1993

[Detection of codon 72 polymorphism of p53 gene from blood and loss of heterozygosity in brain tumors using polymerase chain reaction].

p53 gene which is known as a tumor suppressor gene locates in chromosome 17p and has a polymorphism at codon 72 (Arginine CGC-->Proline CCC). In this study, we examined the frequency of polymorphism and of heterozygosity in Japanese, and the loss of p53 gene in brain tumor tissues of the patients with heterozygosity using a novel method. The frequencies of heterozygosity, arginine type, proline type were 43%, 42% and 15%, respectively. Heterozygosity was observed in 15 out of 32 patients with brain tumors and loss of heterozygosity (LOH) in these 15 cases was demonstrated in 40%. Although we are not certain whether LOH of p53 region is inevitable process of oncogenesis of some brain tumors, some false negative results may occur. This quick technique requires small amount of samples and no radioactive isotope, therefore, can be applied to detect mutation and LOH occurred in p53 region in terms of the genesis and progression of human neoplasms.

Base Sequence↗
PubMed1992

A case of accessory mitral valve leaflet associated with solitary mitral cleft.

Accessory mitral valve leaflet is a rare congenital anomaly. More than half of the cases show other congenital cardiac defects and almost all of the cases show subaortic obstruction. We report a case of an accessory mitral valve tissue without outflow obstruction associated with mitral cleft of the posterior mitral leaflet. To our knowledge, this is the first reported case of the combination of these two congenital anomalies.

Adult↗