A macro analysis of population growth of China's ethnic groups in the 1980s.
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Age Factors↗
Biomedical subjects
W Liu
Publications and source records attributed to W Liu.
The effect of IH764-3 on fibroblast proliferation and function.
The effect of IH764-3, a potent component isolated from Salvia miltiorrhiza, on the proliferation and function of cultured fibroblasts was studied. It was found that the fibroblast growth curve had a dose-dependent relationship with IH764-3 concentration. The incorporation of 3H-TdR and 3H-proline into fibroblasts was significantly inhibited by IH764-3, and calmodulin, fibronectin and thrombospondin contents in the test group were obviously lower than those in the control group. Flow cytometry showed that in the IH764-3-treated group, the percentage of cells in G0/G1 phase was higher than that in the control. Electron microscopic observation (TEM and SEM) showed that in the treated group, collagen secretion was decreased. All of these results indicate that IH764-3 exerts a direct inhibitory effect on fibroblast proliferation and affects their ability to synthesize collagen.
Animals↗
[Effect of oxytocin and cholecystokinin octapeptide (CCK-8) on electroacupuncture (EA) analgesia].
The effect of oxytocin (OT) and cholecystokinin octapeptide (CCK-8) on EA analgesia was studied in rats. The increase of 20.8-39.8% and 9.0-45.0% in pain threshold was observed respectively when ICV of CCK-8 or naloxone was combined with EA, these increases were lower than that in saline-EA group significantly, while the simultaneous ICV of OT and CCK-8 or OT and naloxone in combination with EA produced the increase of 76.2-116.6% and 41.8-104.5% in pain threshold separately. These results showed that only a small part in the role of OT enhancing EA analgesia was blocked by CCK-8 and naloxone. The data suggest that the role of OT in EA was not entirely dependent upon the endogenous opiate peptides.
Acupuncture Analgesia↗
Cloning, characterization and partial sequence analysis of the 5'-flanking region of bovine alpha-sl casein gene.
We have isolated a clone from a EMBL3 constructed bovine genomic library using a PCR-generated DNA fragment as a probe covering-660bp to + 158 bp of boving alpha-sl casein gene. The results obtained from hybridization assay, restriction endonucleases map and partial DNA sequence analysis indicated that the cloned fragment spanned 5.7kb of the first part of the gene and 8.0 kb of its upstream flanking region. Some divergent restriction endonuclease recognition sites and a few mutations and deletions were found in exons, introns and 5'-flanking region of the gene we cloned when compared with the PCR-generated fragment and those which had been published [6,10]. All the deletions occurred at repeat sequences.
Animals↗
[The preparation and clinical use of a radioimmunoassay CA125 kit for the diagnosis of epithelial ovarian cancer].
A self-made radioimmunoassay CA125 kit (using OC125 monoclonal antibody ascites offered by Dr. Bast Laboratory which was purified, solidified and labelled with 125I) was used for serum determination in 80 patients with epithelial ovarian cancer and in 40 standard antigen samples. The results demonstrated a statistically significant correlation between our self-made CA125 kit and an imported CENTOCOR CA125 kit (P < 0.001). Clinical experience before operation in 40 patients with epithelial ovarian cancer, 34 with endometriosis and 39 with other malignant ovarian tumors suggested that the self-made CA125 kit was more sensitive in diagnosing epithelial ovarian cancer than the other two diseases. Post-operative follow-up in 86 non-recurrent cases and 101 recurrent cases showed a 96% positive predictive rate and 91% negative predictive rate. It is concluded that self-made CA125 kit is very useful in monitoring epithelial ovarian cancer.
Antibodies, Monoclonal↗
Characterization of the rate-dependent effects of ethmozine on conduction, in vivo, and on the sodium current, in vitro, in the newborn heart.
We evaluated the effects of ethmozine on resting conduction intervals, myocardial refractory periods and His-Purkinje and intraventricular conduction in vivo in 11 neonatal dogs aged 7 to 16 days. Ethmozine produced significant prolongation in resting sinus cycle length (P < .05), in the atrioventricular nodal (P < .001) and His-Purkinje conduction time (P < .01) intervals and in the QRS duration (P < .01). Ventricular, but not atrial refractory periods were significantly prolonged (P < .05). Rate-dependent changes in His-Purkinje and intraventricular conduction were demonstrated after ethmozine by direct pacing of the bundle of His and right ventricular pacing. The development of steady-state conduction delay at a paced cycle length of 200 msec was characterized by a time constant (tau on) of 23.5 beats. The time constant of diastolic recovery (tau off) from rate-dependent conduction delay, determined during His bundle extrastimulation, was 171 msec. Ethmozine was highly proarrhythmic. A total of 7 arrhythmias were induced in 6 out of 12 neonates after administration of ethmozine. We also characterized ethmozine block of cardiac sodium channels in isolated neonatal canine ventricular myocytes using the whole cell variation of the patch clamp technique. Ethmozine (1.3-40 microM) produced a use-dependent block of cardiac Na channels that was dependent upon both drug concentration and pulse duration. Drug binding to inactivated channel states accounted for the observed use-dependent block. The time constant of recovery from use-dependent block ranged between 10 and 30 sec at 16 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Cloning, mapping, and sequencing of 3' and its flanking region of bovine alpha-s1 casein gene.
A positive clone was isolated from a bovine genomic library in EMBL3 with the probe of alpha-s1 casein gene cDNA. The results from both restriction endonuclease digestion and Southern hybridization probed with the upstream and downstream fragments from the termination codon of bovine alpha-s1 casein gene cDNA suggested that the clone contained 3.5 kb downstream and 10.2 kb upstream fragments from the termination codon of alpha-s1 casein gene. Some divergences in restriction endonucleases sites, a few deletions, and many point mutations were found in introns and exons when compared with those which were published.
Animals↗
[Detection of human papillomavirus (HPV) DNA in carcinoma of uterine cervix and genital tract diseases in Jiangsu province, China].
Pst-1 cleaved DNA restriction fragment length polymorphism (RFLP) of biopsy samples from 41 patients with squamous cell carcinoma of uterine cervix collected in Jiangsu province, China were examined for HPVs by Southern blot hybridization using HPV 16 DNA as a probe. 20 of the 41 samples were positive for HPVs when hybridized under non-stringent condition. HPV was not detectable in samples collected in the same time period from patients with cervical adenocarcinoma (N = 2), vaginal carcinoma (N = 3), vulval carcinoma (N = 1) and benign cervicitis (N = 8). Of the 20 positive samples, 7 (17.1%) had CHPV X1, a new type of NPV previously discovered is China, 6 (14.6%) had HPV 16, 4 (9.9%) had HPV 31, and in 3 (7.2%) the HPV type is as yet undetermined. Our data indicate that HPV 16 and CHPV X1 may be more closely related to cancer of the uterine cervix in Jiangsu province.
Adult↗
Characterization of primary human fetal dissociated central nervous system cultures with an emphasis on microglia.
BACKGROUND: We undertook a systematic examination of human fetal central nervous system dissociated cell cultures, particularly with respect to microglia and their dynamic interactions with other central nervous system cell components. EXPERIMENTAL DESIGN: The growth and differentiation of astrocytes, microglia, and small immature neuronal cells in mixed and single cell type-enriched cultures were followed by phase contrast microscopy, immunocytochemistry, flow cytometry, electron microscopy and immunoelectron microscopy, in regard to their phenotype change, proliferation and class II major histocompatibility complex antigen expression. RESULTS: Both astrocytes and microglia expressed marked phenotype heterogeneity, but they were consistently positive for glial fibrillary acidic protein and CD68, respectively. Highly enriched astrocyte and microglial cultures suitable for biochemical or molecular biologic studies were obtained. Using double immunocytochemical labeling techniques with the proliferating cell nuclear antigen and cell-type specific markers, astrocytes grown in serum-containing media showed a high labeling index, whereas microglia seldom exhibited a similar degree of proliferative activity. Microglia, however, proliferated in response to certain growth factors, such as granulocyte macrophage colony-stimulating factor. Both microglia and astrocytes expressed high basal levels of class II MHC antigens, which further increased with addition of interferon-gamma. The microglia in dissociated cultures existed in two forms, ameboid and ramified. Microglial ramification was induced when ameboid microglia were co-cultured with a monolayer of astrocytes, suggesting a role for astrocytes in microglial differentiation. In addition, lipopolysaccharide in nanogram amounts consistently enhanced microglial survival and morphologic differentiation. The small bipolar cells, the most frequent cell type in mixed culture, were glial fibrillary acidic protein (-) and CD68 (-), and their size and shape remained unchanged under our culture conditions. A subpopulation of small bipolar cells was stained positive with an antibody to surface ganglioside, A2B5. Electron microscopic examination showed that their processes contained parallel microtubules bearing side arms consistent with immature neurons. CONCLUSIONS: Highly purified astrocyte and microglial cultures are obtained using the currently described technique. The current culture system is a valuable tool in studying human central nervous system biology and disease.
Astrocytes↗
Alignment, classification, and three-dimensional reconstruction of single particles embedded in ice.
Cryo-electron microscopy of single biological particles poses new challenges to digital image processing due to the low signal-to-noise ratio of the data. New tools have been devised to deal with important aspects of 3-D reconstruction following the random-conical data collection scheme: (a) a new shift-invariant function has been derived, which promises to facilitate alignment and classification of single particle projections; (b) a new method of orientation search is proposed, which makes it possible to relate random-conical data sets to one another prior to reconstruction; and (c) the foundation is laid for a 3-D variance estimation which utilizes the oversampling of 3-D angular space by projections in the random-conical reconstruction scheme.
Algorithms↗
[A study on spontaneous closure of ventricular septal defect using 2 dimensional echocardiography].
The results of 2 dimensional echocardiographic (2DE) observation in 73 patients with clinically diagnosed spontaneous closure of ventricular septal defect (VSD) were reported. 2DE showed that aneurysm of the membranous septum formed at the defect portion in 54 patients (74%), tricuspid valve leaflet tissue adhered to the defect portion in 2 patients, coarse appearance of the membranous septum in 8 patients, no defect in 9 patients. There was no shunt flow detected in 59 patients, trivial shunt flow in 14 patients on Doppler echocardiography. All VSD were of the membranous and perimembranous inlet type. The results of this study suggested spontaneous closure of membranous VSD was related to the aneurysmal formation of the membranous septum and adhesion of tricuspid valve tissue.
Child↗
[Determination of cinnamaldehyde in cortex Cinnamomi by CS-930 TLC scanner].
Cinnamaldehyde was extracted by chloroform from Cortex Cinnamomi and determined directly on a CS-930 TLC scanner. The method is simple and sensitive, and can serve as an index for checking the quality of Cortex Cinnamomi.
Acrolein↗
[Hypolipodemic action of zhikeqing].
Zhikeqing is a compound prescription of Chinese herbs. It has been proved shown to possess an obvious effect on lipid and lipoprotein cholesterol contents in the serum of hyperlipidemic mice or rats.
Animals↗
Glueballs and topology in lattice QCD with two light flavors.
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Journal Article↗
Function of the N-terminal calcium-binding sites in cardiac/slow troponin C assessed in fast skeletal muscle fibers.
Fast skeletal troponin C (sTnC) has two low affinity Ca(2+)-binding sites (sites I and II), whereas in cardiac troponin C (cTnC) site I is inactive. By modifying the Ca2+ binding properties of sites I and II in cTnC it was demonstrated that binding of Ca2+ to an activated site I alone is not sufficient for triggering contraction in slow skeletal muscle fibers (Sweeney, H.L., Brito, R. M.M., Rosevear, P.R., and Putkey, J.A. (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 9538-9542). However, a similar study using sTnC showed that Ca2+ binding to site I alone could partially activate force production in fast skeletal muscle fibers (Sheng, Z., Strauss, W.L., Francois, J.M., and Potter, J.D. (1990) J. Biol. Chem. 265, 21554-21560). The purpose of the current study was to examine the functional characteristics of modified cTnC derivatives in fast skeletal muscle fibers to assess whether or not either low affinity site can mediate force production when coupled to fast skeletal isoforms of troponin (Tn) I and TnT. Normal cTnC and sTnC were compared with engineered derivatives of cTnC having either both sites I and II active, or only site I active. In contrast to what is seen in slow muscle, binding of Ca2+ to site I alone recovered about 15-20% of the normal calcium-activated force and ATPase activity in skinned fast skeletal muscle fibers and myofibrils, respectively. This is most likely due to structural differences between TnI and/or TnT isoforms that allow for partial recognition and translation of the signal represented by binding Ca2+ to site I of TnC when associated with fast skeletal but not slow skeletal muscle.
Amino Acid Sequence↗
Hadron thermodynamics with Wilson quarks.
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Journal Article↗
Reassessment of the catalytic mechanism of glycogen debranching enzyme.
The amylo-1,6-glucosidase catalytic activity of glycogen debranching enzyme allows it to hydrolyze alpha-D-glucosyl fluoride, in the absence or presence of glycogen or oligosaccharides, releasing equal amounts of fluoride and glucose at rates comparable to those seen with the natural substrates. 2-Deoxy-2-fluoro-alpha-D-glucosyl fluoride is found to be a poor substrate, rather than the covalent inhibitor that would be expected for a glucosidase which catalyzes hydrolysis of the glycosidic linkage with retention of anomeric configuration. In fact, analysis of the glucosidase reaction by NMR reveals that the debranching enzyme hydrolyzes the glycosidic linkage with inversion of configuration, releasing beta-D-glucose from both alpha-glucosyl fluoride and its natural substrate, the phosphorylase limit dextrin. In contrast, its transferase activity necessarily proceeds with retention of configuration. As has been seen with other "inverting" glycosidases, the debranching enzyme releases beta-D-glucose from beta-D-glucosyl fluoride in the presence of oligosaccharides such as maltohexaose and cyclomaltoheptaose but, unlike the others, not in their absence. An intermediate glucosyl-alpha-(1,6)-cyclomaltoheptaose has been detected by NMR analysis. In the presence of a water-soluble carbodiimide, a single mole of glycine ethyl ester is incorporated into each mole of the debranching enzyme, resulting in its inactivation when measured by the combined assay for both transferase and glucosidase activities. Measurement of the latter two activities independently indicates that it is the transferase activity which is inactivated, while the glucosidase activity, measured with alpha-D-glucosyl fluoride as substrate, is unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Chemically unambiguous peptide immunogen: preparation, orientation and antigenicity of purified peptide conjugated to the multiple antigen peptide system.
We described a novel and simple approach to prepare chemically unambiguous peptide immunogen using the multiple antigen peptide (MAP) approach. This approach requires the conjugation of two purified components: a chloroacetylated oligomeric lysine core matrix and a synthetic peptide containing cysteine at either the carboxyl or amino terminus. The resulting MAP is structurally unambiguous and contains a quantifiable amount of peptide antigens. Furthermore, this method also provides a flexible strategy to link a peptide antigen to the core matrix at the desirable orientation to mimic the native molecule. The carboxyl fragment 43-50 of human transforming growth factor alpha (TGF alpha) was used as a test model for this approach. Antipeptide antibodies did not recognize the "reverse immunogen" in which the peptide was attached to the MAP core matrix at a reverse orientation. To determine the specificity of the antibodies, we used two series of point-substituted TGF alpha analogs containing either alanine or the corresponding D-amino acid replacement to map the antigenic site. The alanine analogs were used to determine the contribution of the side chain while the D-amino acid analogs were used to determine the importance of backbone conformation. The antigen site was found to consist of four residues (Asp47-Leu48-Leu49-Ala50) at the distal end of the peptide-MAP conjugate. The results provide a clear explanation for the specificity of the antipeptide antibodies and their failure to recognize the "reverse immunogen" since the distal and the flexible end of the peptide-MAP construct constitutes the antigenic site. Furthermore, our results also suggests a strategy of placing the antigenic portion of a short-peptide at the distal end in the MAP approach to prepare immunogen.
Amino Acid Sequence↗