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D Y Liu

Publications and source records attributed to D Y Liu.

At least 91 records · Page 5Linked to original sources
PubMed1991

Purification, biochemical composition, and biosynthesis of the Mo3 activation antigen expressed on the plasma membrane of human mononuclear phagocytes.

Mo3 is an activation Ag expressed on the surface of human mononuclear phagocytes stimulated in vitro or in vivo by various activating factors. Mo3 is obtained by immunoprecipitation with anti-Mo3 mAb from lysates of PMA-stimulated U-937 cells. The Ag is a heterogeneous glycoprotein with a molecular mass range of 42 to 66 kDa (nonreducing conditions) containing N-linked carbohydrate chains. When the cells are treated with phosphatidylinositol-specific phospholipase C, greater than 60% of total precipitable gp42-66 Ag is released in the supernatant. This phosphatidylinositol-specific phospholipase C-sensitive linkage to the plasma membrane has provided a means for the one-step purification of Mo3 by immunoaffinity chromatography. The eluted soluble Mo3 (sMo3) was greater than 90% pure as documented by the appearance of a single major protein peak on reverse phase HPLC and SDS-PAGE. The average yield was 12.1 micrograms/10(8) cells. Sufficient quantities of sMo3 have been purified to permit the determination of amino acid and carbohydrate composition. Complex N-linked carbohydrates make up nearly 50% of the glycoprotein content and contribute to its heterogeneity. An anti-Mo3 polyclonal antiserum generated from sMo3 was used to immunoprecipitate Mo3 and its precursor from biosynthetically labeled, PMA-stimulated U-937 cells or LPS-stimulated monocytes. These 35S-methionine "pulse-chase" experiments demonstrated the existence of a 40- to 42-kDa endo-beta-N-acetylglucosaminidase-sensitive precursor, which over a period of 4 to 5 h gave rise to an endo-beta-N-acetylglucosaminidase-resistant, but N-glycanase-sensitive 42- to 66-kDa mature form.

Amino Acids↗
PubMed1991

Horse and marmoset monkey sperm bind to the zona pellucida of salt-stored human oocytes.

The present study demonstrates that horse and marmoset monkey sperm can bind to the human zona of salt-stored oocytes that failed to fertilize in vitro. Marmoset monkey sperm are also able to penetrate the salt-stored human zona. In contrast, human sperm do not bind to the zona of either horse or marmoset monkey oocytes. These results suggest that human sperm binding to the zona pellucida is more strictly species-specific than it is for horse and marmoset monkey sperm. In contrast, horse and marmoset monkey sperm contain receptors recognized by the human zona.

Animals↗
PubMed1991

[Study on immunoglobulin allotypes in the Chinese: a hypothesis of the origin of the Chinese nation].

This paper reports the distribution of immunoglobulin Gm and Km allotypes in 74 Chinese geographic populations. These populations are derived from 24 nationalities comprising 96.6% of the total population of China. A total of 9,560 individuals were phenotyped for Gm (1,2,3,5,21) factors and 9,611 for Km(1). Phylogenetic trees were constructed on the basis of Gm haplotype frequencies and genetic distances. The results of clustering analysis show the heterogeneity of the Chinese nation, and confirm the hypothesis that the modern Chinese nation originated from two distinct populations. One population originating in the Yellow River valley, and the other originating, in the Yangtze River valley during the early part of neolithic times (to date 3,000--7,000). Frequencies of the Gm haplotype of 74 Chinese populations were compared with those from 33 populations from major racial groups. The results suggest that during human evolution, the Negroid group and Caucasoid-Mongoloid group diverged first, followed by a divergence between the Caucasoid and Mongoloid. Interrace divergences are high in comparison with interrace divergences. There appear to be two distinct subgroups of Mongoloid, Northern and Southern Mongoloid. The Northern and Southern Mongoloid have Gm1;21 and Gm1,3;5 haplotypes as race associated markers, respectively. Furthermore, the Caucasian associated haplotype Gm3;5 was found in several of the minorities living in the northwest part of China. The amount of Caucasian admixture has been estimated. The presence of the Gm3;5 haplotype is attributed to the Caucasians living in Central Asia throughout the "Silk Road." In contrast to the Gm haplotype distribution, Km1 gene frequencies showed a random distribution in the populations studied.

Asian People↗
PubMed1991

Inhibition of human sperm-zona pellucida and sperm-oolemma binding by antisperm antibodies.

The results of this preliminary investigation suggest that antisperm antibodies interfere predominantly with sperm-zona pellucida binding. The observation of similar numbers of control (Ab-) and test (Ab+) sperm bound to the oolemma implies that the antibody-mediated inhibition of capacitation, acrosome reaction, or oolemma binding may not be major causes of failed fertilization with sperm autoimmunity. However, only seven patients were studied, and further investigation with larger numbers of subjects are required.

Autoantibodies↗
PubMed1990

Use of oocytes that failed to be fertilized in vitro to study human sperm-oocyte interactions: comparison of sperm-oolemma and sperm-zona pellucida binding, and relationship with results of IVF.

A test for human sperm binding to the oolemma was developed with oocytes that failed to be fertilized in vitro. The zonae pellucidae of the oocytes were removed under a dissecting microscope by brief exposure to dilute HCl (pH 2.5-3.0) in 0.9% NaCl. The zona-free oocytes (ZFOs) were incubated with a mixture of equal numbers of motile sperm from men to be tested and fertile donors. The sperm was differentially labelled with fluorescein or rhodamine and the results expressed as a ratio of the number of test to control sperm bound to several ZFOs in order to control for variability in the ability of the oolemma to bind sperm. The number of sperm bound to the oolemma increased with time and sperm concentration. The sperm-oolemma binding ratio determined for 32 patients undergoing in vitro fertilization (IVF) was significantly correlated with the sperm-zona pellucida (ZP) binding ratio but was not correlated with other sperm tests. The sperm-oolemma binding ratio was also related to the IVF rate, but this was not significant if the sperm-ZP binding ratio was included in the logistic regression model. Only four of the 32 patients had failure of fertilization in vitro. The human sperm-oolemma binding test may be useful for studying the interaction between gametes, but the test is unlikely to be as useful clinically as the sperm-ZP binding test for predicting fertilization in vitro.

Female↗
PubMed1990

Relationships between human sperm acrosin, acrosomes, morphology and fertilization in vitro.

Acrosin was measured in the semen used for sperm preparation for in-vitro fertilization (IVF) in 118 patients. Acrosin levels correlated with the proportion of spermatozoa with normal intact acrosomes determined with Pisum sativum agglutinin labelled with fluorescein. However, acrosin levels and the proportion of spermatozoa with normal intact acrosomes in semen were not significantly related to the fertilization rate in vitro. Only the percentage normal morphology and sperm concentration in the insemination medium were independently significantly related to the fertilization rate by logistic regression analysis. In patients with fewer than 30% of spermatozoa with normal morphology, although acrosin levels were not correlated with the fertilization rate, the proportion of spermatozoa with normal intact acrosomes in the insemination medium was the only significant factor in the logistic regression analysis. In conclusion, acrosin levels have no prognostic value for fertilization in vitro but the proportion of spermatozoa with normal intact acrosomes may be a useful clinical marker of fertilizing ability in men with poor sperm morphology.

Acrosin↗
PubMed1990

Human seminal clusterin (SP-40,40). Isolation and characterization.

Molecular cloning of the human complement inhibitor SP-40,40, has revealed strong homology to a major rat and ram Sertoli cell product, sulfated glycoprotein-2, known also as clusterin. This study reports the purification and characterization of human seminal clusterin. Two-dimensional gel electrophoresis revealed charge differences between clusterin purified from semen and the serum-derived material. Both preparations demonstrate comparable hemagglutination (clustering) activity and inhibition of C5b-6 initiated hemolysis. The average clusterin concentration in normal seminal plasma is considerably higher than that found in serum. Mean seminal plasma clusterin concentrations were significantly lower in azoospermia caused by obstruction or seminiferous tubule failure than with oligospermia or normospermia. Only men with vasal agenesis had undetectable seminal clusterin, suggesting that some of the seminal clusterin is produced by the seminal vesicles. Immunofluorescence of human spermatozoa revealed that clusterin was detected on 10% of spermatozoa, predominantly those that were immature or had abnormal morphology. A pilot study of 25 patients suggests that seminal clusterin concentration, together with sperm motility and morphology, is correlated with the fertilization rate in vitro. The function of seminal clusterin is unknown. Its extensive distribution in the male genital tract and its high concentration in seminal plasma suggests an important role in male fertility.

Animals↗
PubMed1990

Inducing the human acrosome reaction with a calcium ionophore A23187 decreases sperm-zona pellucida binding with oocytes that failed to fertilize in vitro.

The human acrosome reaction was induced with the calcium ionophore A23187 and the proportion of reacted spermatozoa was determined with fluorescein-labelled Pisum sativum agglutinin. Human oocytes that failed to fertilize in vitro were used to test binding of spermatozoa to the zona pellucida (ZP) and oolemma. Differential labelling of spermatozoa with fluorescein and rhodamine was used to control for variability in the oocytes. Spermatozoa labelled with one fluorochrome were treated with A23187 and mixed with equal numbers of motile untreated control spermatozoa labelled with the other fluorochrome. The mixture was incubated with zona-intact and zona-free oocytes for 4 h. The sperm-ZP binding ratio of test to control spermatozoa was significantly decreased with increasing proportions of acrosome reacted spermatozoa. In contrast, the sperm-oolemma binding ratio was significantly increased with A23187 treatment. This suggests that acrosome-reacted spermatozoa do not bind to the human ZP.

Acrosome↗
PubMed1990

Human mononuclear phagocyte activation antigens.

Activation of mononuclear phagocytes causes changes in plasma membrane composition that include the expression of surface antigens and receptors. Monoclonal antibody technology has made it possible to identify and characterize newly expressed surface antigens. Among these "activation antigens" is a glycoprotein, Mo3, which (among hematopoietic cells) is selectively expressed by human mononuclear phagocytes that have been exposed to inflammatory factors in vitro and in vivo. Progress toward a functional and structural analysis of Mo3 is described.

Animals↗
PubMed1990

Investigation of the amount of dissolved iron in food cooked in Chinese iron pots and estimation of daily iron intake.

The amount of dissolved iron in food cooked in Chinese iron pots and that in food cooked in aluminum, stainless steel, and clay pots were determined. It was found that the amount of dissolved iron in food cooked in Chinese iron pots was two to five times higher than that in food cooked in the other types of pots. According to the test results, the estimated increase in daily iron intake was about 14.5 mg for adults and 7.4 mg for children when Chinese iron pots were used.

Aluminum↗
PubMed1990

Inductive effects of rifapentine on mice hepatic mixed function oxidase system.

Rifapentine (R773, DL473) is a long-acting antituberculous drug used in China. In our experiments we have found some manifestations of induction of hepatic mixed function oxidase system in mice following pretreatment with rifapentine or phenobarbital. Both rifapentine and phenobarbital significantly increased the rate of antipyrine and pentobarbital metabolism in vivo. They also increased liver weight, the content of liver microsomal protein and cytochrome P-450, the activity of NADPH-cytochrome C reductase and NADPH oxidase. SDS-polyacylamide gel electrophoresis showed that the relative proportions of some polypeptide bands in mice microsomal fraction were significantly changed following rifapentine or phenobarbital pretreatment. The results indicate that rifapentine, like phenobarbital, is a potent inducer of hepatic mixed function oxidase system in mice and that it should be used carefully in clinical therapy, when combined with other drugs.

Animals↗
PubMed1989

Identification of a human monocyte antigen (Mo3e) associated with cellular activation and lymphokine responsiveness.

A murine monoclonal IgM antibody recognizes an antigen (Mo3e) found on the surface of human peripheral blood monocytes stimulated with phorbol 12-myristate 13-acetate (PMA), lipopolysaccharide and muramyl dipeptide and blocks the monocyte response to migration inhibitory factor (MIF). We utilized Western blot and immunoprecipitation analyses of whole cell lysates to investigate the biochemical nature of this monocyte antigen. Two distinct bands (75 kDa and 50 kDa) were detected by anti-Mo3e after monocyte lysates were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transblotted onto nitrocellulose paper. Stimulation of monocytes with PMA resulted in a marked increase in the amount of the 50-kDa species. Immunoprecipitation of Mo3e from lysates of surface-iodinated cells demonstrated one broad band at 55-80 kDa which increased after PMA stimulation. The epitope identified by anti-Mo3e was resistant to 2-mercaptoethanol and heat treatment (100 degrees C/5 min) and was sensitive to trypsin or papain treatment. Two-dimensional SDS-PAGE analysis revealed that the 75-kDa species has an isoelectric point of 7.0 and the 50-kDa species is more acidic with an isoelectric point of 5.3. These results indicate that anti-Mo3e antibody defines unique monocyte proteins that may play a role as suggested by previous studies, in monocyte activation and responsiveness to MIF.

Antibodies, Monoclonal↗
PubMed1989

Subunit composition and specificity of the major cyst fluid antigens of Echinococcus granulosus.

The subunit composition and specificity of the major Echinococcus granulosus cyst fluid antigens were determined by immunochemical analysis using murine monoclonal antibodies against Antigen 5 and Antigen B and human sera. Immune complexes cut out from immunoelectrophoresis gels and murine hybridomas were used as a source of specific anti-Antigen 5 and anti-Antigen B antibodies. Immunoprecipitation and Western blot analyses in sodium dodecyl sulphate-polyacrylamide gels using these reagents identified Antigen 5 to be a heterodimer composed of 24-kDa and 38-kDa subunits linked by disulphide bonding. Antigen B comprised a regularly spaced group of molecules with the smallest subunit estimated to be 8 kDa and the other components each differing in size by approximately 8 kDa, i.e., 16 kDa, 24 kDa, 32 kDa etc.; all possibly derived from the 8-kDa monomer. The relative abundance of the Antigen B subunits decreased asymptotically with increasing molecular weight. Neither the Antigen 5 nor the Antigen B subunit was specific for E. granulosus. Both antigens generated readily detectable levels of specific antibody in the sera of patients with Echinococcus multilocularis, Echinococcus vogeli or E. granulosus infection. Relatively high levels of antibody to Antigen 5 were also detected in the sera of patients infected with Taenia solium. The presence of phosphorylcholine epitope(s) on Antigen 5 was confirmed.

Animals↗
PubMed1989

A sperm-zona pellucida binding test and in vitro fertilization.

Sperm binding to the zona pellucida was studied in 106 in vitro fertilization (IVF) patients. Oocytes that failed to fertilize in vitro were inseminated with a mixture of equal numbers of test and fertile donor sperm differentially labeled with fluorescein or rhodamine to control for variability in the sperm-zona pellucida binding capacity of oocytes. The ratio of the number of test and control sperm bound to four to six zonae pellucidae was significantly correlated with sperm morphology, viability, motility, motility index, and normal intact acrosomes in semen. The sperm-zona pellucida binding ratio was the most significant factor related to IVF rates by logistic regression analysis. But the proportions of sperm with normal morphology and intact acrosomes in semen also were significant. In patients with less than 30% of sperm with normal morphology, there was a highly significant relationship between IVF rate and sperm-zona pellucida binding and a weaker relationship with sperm morphology. In conclusion, the sperm-zona pellucida binding ratio test is useful for predicting sperm fertilizing ability in vitro, particularly in men with poor sperm morphology.

Cell Survival↗
PubMed1989

Human sperm-zona pellucida binding, sperm characteristics and in-vitro fertilization.

The number of sperm bound to the zona pellucida (ZP) were counted on 660 oocytes that failed to fertilize in vitro from 162 patients. Oocytes from clutches in which some fertilized had significantly more sperm bound to the ZP than did those from clutches in which all oocytes failed to fertilize. Oocytes from patients in whom all were not fertilized and no sperm bound to the ZP were able to bind normal fertile donor sperm after storage in ammonium sulphate solution. The number of sperm bound to the ZP was significantly related to the proportion of sperm with normal morphology and normal intact acrosomes in semen, sperm concentration inseminated, sperm motility and viability. The number of sperm bound to the ZP, sperm normal morphology, diagnosis of male infertility and sperm concentration in semen were significantly related to the fertilization rate by logistic regression analysis. Thus the number of sperm bound to the ZP is an indicator for IVF success and low binding appears to be more frequently associated with sperm defects than oocyte defects.

Adult↗
PubMed1989

[An evaluation of lymphangiography in the diagnosis of nodal metastasis from genitourinary cancer].

From September 1979 to March 1988, lymphangiography was carried out in 187 cases of genito-urinary cancers and the specific features of metastatic lymph-nodes have been summarized. The results showed that the false positive was much lower in bladder, testicular, and prostatic cancers than in penile cancer. In order to enhance visualization of the pelvic, lumbar and kidney-hilar nodes, a combined lymphangiography should be done through both bipedal and funicular routes. A percutaneous FNAB is necessary to minimize the false positive.

Adult↗