Biomedical subjects
Y Yao
Publications and source records attributed to Y Yao.
Tris(2,6-di-tert-butyl-4-methylphenolato-O)(triphenylphosphine oxide-O)samarium(III).
In the title complex, [Sm(C(15)H(23)O)(3)(C(18)H(15)OP)], the central metal atom is coordinated by three O atoms of the aryloxo ligands and by one O atom of the triphenylphosphine oxide molecule resulting in a distorted tetrahedral geometry. The Sm-O(Ar) distances (Ar is aryl) range from 2.122 (2) to 2.190 (2) A and the Sm-O(PPh(3)) bond length is 2.306 (2) A.
Effect of human hydrosalpinx fluid on in vitro mouse embryogenesis.
OBJECTIVE: Women with hydrosalpinx have an unfavorable pregnancy rate. As one approach to elucidate the effect of hydrosalpinx on uterine tubal functioning, we examined the effect of hydrosalpinx fluid on early embryo development in mice. METHODS: Hyperovulation was induced in ICR mice, and late 2-cell-stage embryos were harvested 42 hours after administration of human chorionic gonadotropin (hCG). Hydrosalpinx fluid was obtained from patients during surgery after informed consent was obtained. The embryos were cultured in 3 culture fluids: (1) mBWW medium containing 0.3% bovine serum albumin (positive-control medium) (BSA), (2) Ca2+, Mg2+-free phosphate buffered saline (negative-control medium) (PBS), and (3) 100% human hydrosalpinx fluid. The developmental status of the embryos 120 hours after hCG administration was examined. RESULTS: Embryogenesis from a 2-cell-stage embryo to a blastocyst was observed in 98.3% (118/120) of the embryos cultured in the mBWW medium, in 0% (0/120) of the embryos cultured in PBS, and in 98.3% (118/120) of the embryos cultured in 100% human hydrosalpinx fluid. CONCLUSION: In the micro-environment of human hydrosalpinx fluid, late 2-cell embryos of ICR mice developed normally to blastocysts. The present results also suggest that non-species-specific embryogenetic factors might be present in human hydrosalpinx fluid.
Pellicle precursor protein crosslinking characterization of an adduct between acidic proline-rich protein (PRP-1) and statherin generated by transglutaminase.
Recent work with oral transglutaminase indicated that this enzyme, derived from oral epithelial cells, crosslinked pellicle precursor proteins which may be important in the formation of the acquired enamel pellicle. The purpose of this study was to investigate whether purified acidic PRP-1 can form crosslinks with statherin, and whether such a crosslink is derived from a transglutaminase-catalyzed reaction between glutaminyl and lysyl side-chains, leading to a covalent bond formation. Enzymatic reaction products were analyzed by SDS-PAGE and reverse-phase HPLC. The SDS electrophoretogram revealed a protein band with an apparent molecular weight of 32 kDa, which is consistent with the combined apparent molecular weight of acidic PRP-1 (24 kDa) and statherin (8 kDa). A reaction product isolated by HPLC was characterized by amino acid analysis, which showed a stoichiometry consistent with being an adduct composed of one molecule of acidic PRP-1 and one molecule of statherin. In negative control experiments, it could be shown that this adduct was not detected when the lysines of both substrates were modified by reductive methylation prior to the enzymatic reaction. In addition, amino acid analysis and mass spectrometry confirmed the presence of a gamma-glutamyl-epsilon-lysine dipeptide after enzymatic hydrolysis and the absence of this dipeptide after acid hydrolysis. Analysis of the data obtained indicates that oral transglutaminase is capable of crosslinking acidic PRP-1 and statherin in vitro. In addition, this finding exemplifies the potential of post-secretory processing of salivary proteins, which may represent an additional mechanism to generate new protein species.
The protein kinase C beta-specific inhibitor LY379196 blocks TPA-induced monocytic differentiation of HL60 cells the protein kinase C beta-specific inhibitor LY379196 blocks TPA-induced monocytic differentiation of HL60 cells.
The ability of the promyelocytic leukemia HL60 cell line to differentiate in response to various stimuli has provided a widely used model of differentiation. The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), acting via its cellular receptor protein kinase C(PKC), induces these cells to acquire a monocytic phenotype. We set out to identify the specific isoform of the multigene PKC family that is involved in this differentiation event. To do so, we utilized a highly specific PKCbeta inhibitor, LY379196. We found that LY379196 could prevent the growth arrest, cellular adherence, and changes in several marker proteins that occur after the addition of TPA to HL60 cells and that these effects were not simply due to nonspecific cytotoxicity. Thus, the present studies provide strong evidence that the beta isoform of PKC plays a critical role in TPA-induced HL60 monocytic differentiation.
Epidermal growth factor induces cell cycle arrest and apoptosis of squamous carcinoma cells through reduction of cell adhesion.
Most squamous epithelial cells are strictly anchorage-dependent cell types. We observed that epidermal growth factor (EGF) promoted the growth of A431 squamous carcinoma cells in suspension cultures but suppressed cell growth and induced apoptosis in monolayer cultures, suggesting that loss of adhesion is responsible for the effects observed in monolayer culture, before cell death. Consistent with this finding, we demonstrated that EGF reduced cell attachment, cell-cell interaction, and cell spreading. Treatment with EGF increased cell adhesion-regulated expression of p21 but suppressed expressions of cyclin A, D1, cdk2, and retinoblastoma protein (pRb), leading to cell cycle arrest and adhesion-regulated programmed cell death. To test directly whether promoting cell adhesion could reduce the effects of EGF, we grew cultures on plates coated with type II collagen. On these plates, cell adhesion was enhanced and EGF treatment had little effect on cell adhesion and apoptosis when cells were attached to the collagen. The collagen effects were dose dependent, and cell cycle and cell cycle-associated proteins were altered accordingly. Finally, when cultures were plated on bacterial Petri dishes, which completely disrupted cell attachment to substratum, the level of apoptosis was greatly higher and cell cycle was arrested as compared with monolayer cultures. Taken together, our results strongly suggest that the EGF-induced cell cycle arrest and apoptosis in monolayer cultures was the result of a decline in cell adhesion.
Study on DNA polymorphism at D1S8 locus in Hebei Han population.
OBJECTIVE: To study the polymorphism at D1S8 locus and to provide basic information for the construction of DNA fingerprint database and the application in forensic medicine. METHODS: Minisatellite variant repeat-polymerase chain reaction (MVR-PCR) and polyacrylamide gradient gel electrophoresis followed by silver staining were used to detect the variant repeat sequences at D1S8 locus of 240 unrelated individuals in Hebei Han population, and digital codes were obtained. RESULTS: Each individual obtained about 30 digital codes, in which none of two unrelated individuals had the same code. The probability of identity of 30 digital codes was 3.55x10(-11). The percentages of three repeat units, a-type, t-type and o-type were 54.77%, 42.54% and 2.69% respectively. The heterozygosity (H) was 0.9837. The excluding probability of paternity(EPP) and polymorphism information content(PIC) were 0.9669 and 0.9833 respectively. CONCLUSION: Because of its high polymorphic nature, D1S8 locus is a valuable marker for forensic identification and paternity testing.
Fas ligand expression and apoptosis in primary rat hepatocytes induced by lipopolysaccharide.
OBJECTIVE: To study hepatocyte apoptosis induced by lipopolysaccharide (LPS) directly and indirectly, and to elucidate the mechanisms of liver damage in endotoxemia. METHODS: Rat hepatocytes were isolated using collagenase perfusion, and cultured in RPMI 1640 medium. After 24h or 48 h of LPS treatment at various concentrations (1, 5, 10 mug/ml), membrane-bound Fas ligand (mFasL) expression in hepatocytes was determined by immunocytochemistry, and apoptosis was detected by TUNEL. In another set of experiments it was examined whether LPS-treated hepatocytes and its supernatants can stimulate apoptosis in LPS-untreated hepatocytes. RESULTS: LPS markedly stimulated mFasL expression and apoptosis in hepatocytes in a dose and time (24-48 h) dependent manner. In the co-culture system LPS-treated hepatocytes significantly induced LPS-untreated hepatocyte apoptosis. In contrast, there was no apoptotic cells observed in the supernatant stimulation system. CONCLUSION: LPS not only directly causes hepatocyte apoptosis, but also indirectly induces apoptosis of LPS-untreated hepatocytes by way of stimulating mFasL expression in hepatocytes.
[Cu, Co and Se nutritive value of compound trace elements controlled-release boluses for grazing ruminants].
Twenty cattle with the similar old and weight were randomly divided into two groups for 135 d, while twenty white goats were randomly divided into two groups for 60 d. Each group consisted of ten animals, and the ratio of male and female was same. Each of animals in one group was administered an initial bolus, used as treatment group. In the other group, animals were not administered the bolus, used as control group. In the cattle feeding experiment, five cattle of each group was supplemented feed, and the other five cattles were not supplemented feed. In the goat feeding experiment, all of goats were grazing, and not supplemented feed. At the end of goat feeding experiment, three goats of each group were randomly selected to slaughter. Liver, kidney, spleen, muscle, heart, blood and matter in the rumen were collected to assay for Cu, Co and Se. The results showed that the average daily gain of cattle supplemented and no supplemented feeds in the administered and no administered group was 483.00 g, 302.83 g, 445.84 g and 282.23 g, respectively. There had significantly difference between the administered group and no administered group(p < 0.05). The average daily gain of goats in the administered and no administered groups was 68.83 g and 50.67 g, and significant difference between the two groups (p < 0.01). Administering the boluses improved the contents of Cu, Co and Se in the tissues of goats, significantly.
Evidence of apoptotic smooth muscle cells in proliferative intima of injured arteries.
OBJECTIVE: To investigate the occurrence and extent of apoptosis in the course of restenosis. METHODS: The experimental models of vessel narrowness and intima thickness were established in minipigs' iliac arteries by balloon injury and specimens were retrieved on the 1st, 3rd, 6th, 12th and 30th days for dynamic observation. Apoptotic smooth muscle cells (SMCs) were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). RESULTS: Apoptotic SMCs occurred only in the thickened intima 12 days after injury accompanied with the proliferative SMCs, the percentage of apoptosis was 1.94% +/- 0.42% on the 12th day and 1.36% +/- 0.31% on the 30th day respectively. The low frequency of apoptosis compared with the proliferative SMCs was a feature in the restenotic pathology. CONCLUSIONS: Apoptosis participates in the pathogenetic process of intimal thickening and its level was low compared with proliferation. The findings suggest that attempts to modulate apoptosis after vessel injury constitute a theoretical approach to the prevention of restenosis.
[The study on correlation of c-myc expression with vascular smooth muscle cell proliferation in uterine spiral arteries of pregnancy induced hypertension].
OBJECTIVE: To investigate c-myc proto-oncogene expression of uterine spiral arteries in pregnancy induced hypertension (PIH) and the relationship of this expression with vascular smooth muscle cell (VSMC) proliferation in uterine spiral arteries of PIH. METHODS: Forty-nine placental bed biopsies, 29 from women with PIH and 20 from normotensive pregnant women, were taken during cesarean section. The expression of c-myc in uterine spiral arteries was detected and localized by in situ hybridization. Histological changes of placental bed biopsies were evaluated by HE staining. RESULTS: The positive rate of c-myc was 63.6% (7/11) in moderate PIH and 72.2% (13/18) in severe PIH respectively. They were significantly higher than that in normotensive pregnancy (P < 0.05, P < 0.01, Fisher exact test). 54.5% (6/11) of moderate PIH and 55.6% (10/18) of severe PIH had VSMC proliferation. This was only 10.0% (2/20) in normotensive pregnancy. It was significantly lower than those of moderate and severe PIH (P < 0.05, P < 0.005, Fisher exact test). In PIH cases the VSMC proliferation in uterine spiral arteries was correlated with higher c-myc expression (chi-square test, P = 0.0093). CONCLUSION: c-myc expression is higher in VSMC of uterine spiral arteries in PIH. VSMC Proloferates obviously in uterine spiral arteries of PIH cases. VSMC proliferation in PIH may be associated with c-myc expression.
[The effect of pentoxifylline on endotoxin-induced biopterin formation in rabbits].
OBJECTIVE: To observe the potential effect of pentoxifylline on endotoxin-mediated biopterin (tetrahydrobiopterin and more oxidized species) formation and systemic hemodynamics. METHODS: Rabbits were subjected to endotoxic shock induced by a bolus intravenous injection of E. coli O26B6 lipopolysaccharide (400 microg/kg). 28 animals were divided into sham-operation group (n = 8), endotoxic shock group (n = 10), and pentoxifylline-treated group (n = 10). Plasma biopterin and tumor necrosis factor-alpha (TNF) levels, and guanosine triphosphate cyclohydrolase I (GTP-CHI) activity in tissues were determined at various intervals. RESULTS: Treatment with pentoxifylline significantly decreased plasma biopterin and TNF levels at 2 to 8 hours after endotoxin challenge (P < 0.05, P < 0.01), and inhibited GTP-CHI activities in the liver, lung, and myocardial tissues (P < 0.05). Meanwhile, systemic hemodynamic parameters, including mean arterial pressure, cardiac output, and total peripheral resistance, in the treatment group were much higher than those in the endotoxic shock group. CONCLUSIONS: These data suggest that early treatment with pentoxifylline can effectively inhibit endotoxin-induced biopterin synthesis and release, and markedly improve systemic hemodynamics during septic shock.
[Kidney transplant patients with hepatitis C virus infection:clinical, pathologic, and immunohistochemical study].
OBJECTIVE: To evaluate the clinical results of kidney transplant patients with hepatitis C virus (HCV) infection. METHODS: We tested the sera from 67 patients for anti-HCV and HCV RNA using second generation ELISA and Nest-PCR; HCV-NS3, NS5 were tested by immunohistochemistry LSAB. All patients were followed up for 1 year. RESULTS: The prevalence of anti-HCV was 50.75% (n = 34), and the rate of HCV RNA was 47.76% (n = 32). The HCV RNA positive group had a much longer duration of dialysis and had received more blood transfusion than HCV RNA negative group before transplantation. ALT levels and prevalence of liver dysfunction were significantly higher in HCV RNA positive group after transplantation; however, there was no difference in infection, rejection, graft survival and serum creatinine level. LSAB suggested that HCV-NS3, NS5 antigen of two from three liver bioptic specimens with HCV RNA positive patients were positive. CONCLUSIONS: HCV infection in renal transplant patients can result in liver disease, and is not significantly associated with infection, rejection, and graft survival within a short time. We consider HCV not a contraindication to renal transplantation.
[The effect of splenectomy on circulating endotoxin clearance and tissue distribution of endotoxin in rats].
OBJECTIVE: To study the effect of splenectomy on circulating endotoxin clearance and tissue distribution of endotoxin, and investigate the potential mechanism(s) underlying inflammatory response and multiple organ damage following splenectomy. METHODS: 112 male Wistar rats were randomly divided into two groups: control group (n = 56, included omentectomy and mobilization of the spleen), and splenectomy group (n = 56). The latter was further sub divided into 10-min, 0.5-, 1.5-, 4-, 12-, 24-hour groups after endotoxin challenge. Tissue and systemic blood endotoxin concentrations were measured using the chromogenic limulus amebocyte lysate (LAL), which was modified by perchloric acid (PCA) pretreatment for samples. Liver function parameter and lung tissue myeloperoxidase (MPO) were also measured. RESULTS: After endotoxin administration, plasma endotoxin concentrations were higher in splenectomized rats than in controls at 10 minutes and 0.5 hour (P < 0.01). Endotoxin clearance was delayed in liver and lung in animals after splenectomy. MPO values of the control group were significantly higher than those of splenectomy groups (P < 0.01). CONCLUSION: Splenectomy can lead to impairment of intravascular clearance of endotoxin and endotoxin accumulation in liver and lung. Endotoxin accumulated in local sites may be involved in the development of inflammatory response and multiple organ dysfunction following splenectomy.
[The sifnificance and characteristics of the internal distribution of Staphylococcal enterotoxin B in burned rats with sepsis].
OBJECTIVE: To investigate the role of staphylococcal enterotoxin B (SEB) in the development of postburn staphylococcus aureus sepsis. METHODS: Rats inflicted with 20% TBSA III degree scald followed by Staphylococcus aureus sepsis were used as the experimental subjects. The distribution of SEB in the vital organs such as the heart, liver, lungs, kidneys and plasma was observed with concomitant serial measurement of the relative organ functional indices. RESULTS: The plasma SEB content increased transiently in the early stage of sepsis (P < 0.01) and then fell to near that of control group. The SEB contents in the heart, liver, lungs and kidneys increased evidently 2 hours after staphylococcus aureus challenging (P < 0.01) and continued to increase afterwards. The functions of multiple organs were impaired obviously at 24 postburn hours, and the function impairment was aggravated by S. aureus challenge. The degree of organ injury of liver and kidneys correlated positively with tissue content of SEB (P < 0.05 similar 0.01). CONCLUSIONS: Staphylococcal enterotoxin B might play a role in the development of MODS induced by postburn sepsis.
[The significance of the expressions of lipopolysaccharide binding protein mRNA and lipopolysaccharide receptor CD14 mRNA in the liver of burned rat].
OBJECTIVE: To explore the significance and the correlation between enteric endotoxin translocation and hepatic endotoxin -- sensitivity -- enhancing system--lipopolysaccharide -- binding protein (LBP)/lipopolysaccharide receptor CD14 (LBP/CD14) after burn. METHODS: Wistar rats subjected to 35% III degree burn were employed as the model. The rats were randomly divided into three groups: i.e. normal control (C, n = 8) group, thermal injury (T, n = 10) group and recombinant bactericidal/permeability -- increasing protein (rBPI(21)) treatment (R, n = 6) group. The rats in T and R groups were sacrificed at 12 postburn hour (PBH) and the liver tissue was collected for the detection of the mRNA expressions of LBP, CD14 and tumor necrosis factor (TNFalpha) and blood samples collected for hepatic functional indices. RESULTS: The hepatic endotoxin content increased significantly postburn (P < 0.01), and the expressions of LBP/CD14 and TNFalpha mRNA in liver tissue increased obviously. However the use of rBPI(21) could evidently lower hepatic endotoxin content and inhibit the expression of tissue LBP/CD14 and TNFalpha. In addition, rBPI(21) could also significantly decrease serum level of glutamic -- pyruvic transaminase (ALT) (P < 0.01). CONCLUSION: Aggregation of endotoxin in liver due to postburn translocation might obviously stimulate the expression of LBP/CD14 mRNA locally. The up -- regulation of the expression of LBP/CD14 might be the principle molecular basis enhandced activity of translocated endotoxin on inflammatory cells.
[The correlation of serum levels of insulin-like growth factors and intrauterine growth: report of a study in rats].
This animal experiment was designed to investigate the relationship of the serum insulin-like growth factors (IGFs) with fetal intrauterine growth. The serum concentrations of IGF-I, -II in 21 fetal rats were measuerd and their relationships with fetal birth weight, length and tissue weights of brain, lung, liver were analysed respecively. The results showed that both of the serum concentrations of IGF-I, -II were positively correlated (P < 0.01) with fetal birth weight, length and tissue weights of brain, lung, liver respectively. These data suggest that both IGF-I and IGF-II may play an important role in fetal intrauterin growth and their decreased concentrations in serum may be factors contributing to fetal intrauterine growth retardation.
[The clinical study of tongue flaps repairing after resecting pharyngeal neoplasm and laryngeal neoplasm].
OBJECTIVE: To study the repair methods of the defect after resecting pharyngeal neoplasm and laryngeal neoplasm. METHODS: Four kinds of tongue flap, such as 1/3 tongue flap, 1/2 tongue base flap, tongue base flap and transverse tongue flap were devised and applied in 15 patients with pharyngeal neoplasm and laryngeal neoplasm. RESULTS: These tongue flaps were alive in all patients. The wound of 13 patients healed in I stage. Two patients dehiscenced because of infection and healed after treatment. All the patients deglutited well. One-year, 3-year, disease-free survive rate were 92.9% (13/14), 72.7% (8/11) respectively. CONCLUSION: Tongue flaps are obtained easily, with enough blood flow, adapted to pharyngeal environment, easily alive and low complication in repairing the pharyngeal defect. We think that these tongue flaps should be applied in clinic.