Search PubMed⌕ Search

Biomedical subjects

Y C Liu

Publications and source records attributed to Y C Liu.

At least 289 records · Page 16Linked to original sources
PubMed1986

Zonal chromatographic analysis of the interaction of alcohol dehydrogenase with blue-sepharose.

The interaction between horse liver alcohol dehydrogenase and Reactive blue 2 immobilized on Sepharose CL-6B was measured by zonal chromatography. Each protein molecule was retained by a single immobilized dye using a Blue-Sepharose column containing a total of 1.38 mM dye. However, the protein was predominantly retained by two immobilized dye molecules using a darker Blue-Sepharose column containing a total of 11.6 mM dye. The dissociation constant measured for the alcohol dehydrogenase--immobilized dye complex on each column is identical to the inhibition constant for the alcohol dehydrogenase--free Reactive blue 2 complex: 4.5 +/- 0.8 microM.

Alcohol Oxidoreductases↗
PubMed1986

Nonmuscle tropomyosin from ascites tumor cell microvilli.

Tropomyosin has been isolated from microvilli preparations from 13762 rat mammary adenocarcinoma ascites tumor cells by Triton extraction and pelleting of the microvillar microfilament core, extraction of the microfilament core with 1 M KCl, heat treatment, and hydroxyapatite chromatography. Three major isoforms, designated 31K-a (acidic), 31K-b (basic), and 29K, were identified as tropomyosins by two-dimensional isoelectric focusing-dodecyl sulfate electrophoresis, a urea shift on dodecyl sulfate electrophoresis, chemical cross-linking, amino acid analysis, and molecular weight determinations. The native (60,000) and subunit (31,000 and 29,000) molecular weights, the amino acid composition, and the stoichiometry for binding to F-actin (actin/tropomyosin, 6:1) were typical of nonmuscle tropomyosins. The amount of tropomyosin present in the microvilli preparations is sufficient to saturate about half of the microvillar F-actin. By two-dimensional isoelectric focusing-dodecyl sulfate electrophoresis, the 31K isoforms appeared similar to isoforms of normal rat kidney cells but the 29K isoform was apparently smaller than any normal rat kidney isoforms. All three isoforms bound to F-actin, but the 29K form bound most strongly. Its behavior was similar to that of muscle tropomyosin, exhibiting saturable binding as a function of both ionic strength and Mg2+ concentration. In contrast, the 31K isoforms bound more weakly and required higher concentrations of Mg2+ for binding than that required for saturation with 29K (4 mM). These results clearly indicate that nonmuscle tropomyosin isoforms from a single source and location (subplasmalemmal) in the cell can exhibit different properties.

Actins↗
PubMed1986

Klebsiella pneumoniae liver abscess associated with septic endophthalmitis.

Metastatic septic bacterial endophthalmitis is a rare, but devastating disease. We encountered seven cases of pyogenic liver abscess associated with septic endophthalmitis during a recent four-year period. The causative organism was a pure culture of Klebsiella pneumoniae. The diagnosis was made by results of a blood culture in seven of the cases, liver aspirate culture in four, and eye contents or conjunctival culture in four. Chest roentgenographic examination showed pulmonary embolization in four patients, purulent meningitis in one patient, and suspicious prostatic abscess in one patient. Despite diligent antibiotic therapy, six patients lost their vision and one had impaired vision. This poor outcome for septic endophthalmitis seems to result from delayed diagnosis and lack of scheduled periocular injections of antibiotics. A combination course of treatment by the internist and ophthalmologist acting aggressively, both diagnostically and therapeutically, is needed in the future. To have seven cases of K pneumoniae liver abscess complicated by septic endophthalmitis during a period of four years in one hospital is very unusual. To our knowledge, it has never been reported in the literature.

Adult↗
PubMed1984

Quantitative analysis of protein: immobilized dye interaction.

The interaction of rabbit muscle lactate dehydrogenase with reactive blue 2 immobilized on Sepharose CL-6B was quantitatively evaluated by analytical procedures using both frontal and zonal chromatography and also static equilibrium methodology. All three analytical procedures give a common result, namely (i) that each enzyme molecule is retained by a single immobilized dye molecule; (ii) that the immobilized dye binds to the protein at an NADH binding site with an affinity identical to that of the free dye; and (iii) that less than 2% of the immobilized dye is accessible to the enzyme. The very small fractional accessibility is not due to steric exclusion but likely is a result of adsorption of the immobilized dye to the matrix surface.

Animals↗
PubMed1984

Shared idiotopes among monoclonal antibodies specific for A/PR/8/34 (H1N1) and X-31(H3N2) influenza viruses.

A monoclonal antibody specific for the hemagglutinin (HA) of influenza A X-31 (H3N2) virus (X-31) was obtained during a fusion of spleen cells from a BALB/c mouse immunized with influenza A/PR/8/34 (H1N1) virus (PR8). This monoclonal antibody (Py206) shares crossreactive idiotopes expressed on several monoclonal antibodies specific for PR8 HA and X-31 HA as well as an individual idiotope shared with one monoclonal antibody specific for X-31 HA. The presence of shared idiotypy among antibodies of such diverse binding specificities may result from regulation by idiotype-specific T cells. In addition, the results suggest that, in contrast to the diversity of paratypes expressed, relatively few germ-line variable region genes may be used in the antibody response to influenza A virus antigens.

Animals↗