Biomedical subjects

Z M Yang

Publications and source records attributed to Z M Yang.

At least 19 recordsLinked to original sources

PubMed2006

Acrosome-specific gene AEP1: identification, characterization and roles in spermatogenesis.

Spermatogenesis is a tightly regulated process leading to the development of spermatozoa. To elucidate the molecular spermatogenic mechanisms, we identified an acrosome-specific gene AEP1 in spermatids, which is located in rat chromosome 17p14 with a transcript size of 3,091 bp encoding a signal peptide, zinc finger-like motif, coiled-coil region, several predicted glycosylation and phosphorylation sites. Northern blot and RT-PCR analyses revealed the restricted expression of AEP1 to the testis only. In postnatal rat testes, AEP1 mRNA became detectable from postnatal 25 dpp (round spermatids) and onwards. By using in situ hybridization (ISH) and flow cytometry-fluorescent ISH, only the haploid spermatids yielded the positive AEP1 signal. Immunohistochemistry showed that AEP1 was expressed in the acrosomal cap of late-staged germ cells in rat testis, and co-localized with the acrosomal marker, peanut agglutinin. The spatial expression of AEP1 immunoreactivity in testis was conserved among diverse mammalian species (rat, pig, monkey, human). To further study its roles in spermatogenesis, we showed AEP1 and beta-actin was associated together in complex by co-immunoprecipitation in adult germ cells and by immunofluorescence assay in isolated spermatozoon. In human testes diagnosed with hypospermatogenesis, lower expression of AEP1 was observed, whereas there was no detectable signal in undescended testes. In short, AEP1 is an evolutionary-conserved acrosome-specific gene and likely functions in acrosome-cap formation.

Acrosome↗

PubMed2005

Role of fascin in the proliferation and invasiveness of esophageal carcinoma cells.

Fascin, an actin-bundling protein, induces membrane protrusions and increases cell motility in various transformed cells. The overexpression of fascin in esophageal squamous cell carcinoma (ESCC) has been described only recently, but the roles and mechanism still remained unclear. Here, by using RNA interference (RNAi), we have stably silenced the expression of the fascin in EC109 cells, an ESCC cell line. Down-regulation of fascin resulted in a suppression of cell proliferation and as well as a decrease in cell invasiveness. Furthermore, we revealed that fascin might have functions in regulating tumor growth in vivo. The effect of fascin on cell invasiveness correlated with the activation of matrix metalloproteases such as MMP-2 and MMP-9. We examined that fascin down-expression also led to a decrease of c-erbB-2 and beta-catenin at the protein level. These results suggested that fascin might play crucial roles in regulating neoplasm progression of ESCC.

Animals↗

PubMed2005

Differential expression of prostaglandin E receptor subtype EP2 in rat uterus during early pregnancy.

PGE2 is essential for mammalian female reproduction. This study was to examine the expression of EP2 gene in the rat uterus during early pregnancy, delayed implantation and artificial decidualization by in situ hybridization and immunohistochemistry. There was no detectable EP2 mRNA expression in the uterus from days 1 to 4 of pregnancy (day 1 = day of vaginal sperm). A low level of EP2 immunostaining was observed in the luminal and glandular epithelium from days 1 to 4 of pregnancy. Both EP2 mRNA and protein expression were highly detected in the luminal epithelium at implantation sites on day 6 of pregnancy. EP2 expression decreased from day 7 of pregnancy and was undetectable on days 8 and 9 of pregnancy. After delayed implantation was terminated by estrogen treatment and the embryo implanted, both EP2 mRNA and protein expression were strongly observed in the luminal epithelium at the implantation site. There was no detectable EP2 expression in both control and decidualized uteri. In conclusion, these data suggest that EP2 expression at implantation site may play an important role during embryo implantation in rats.

Animals↗

PubMed2004

Uterine expression of implantation serine proteinase 2 during the implantation period and in vivo inhibitory effect of its antibody on embryo implantation in mice.

The aim of the present study was to examine the uterine expression pattern of implantation serine proteinase 2 (ISP2) protein during early pregnancy in mice and the effects of anti-ISP2 antibody on embryo implantation. Expression of ISP2 protein was found to be specifically up-regulated in mouse uterine endometrial glands following the initiation of embryo implantation. Similarly, ISP2 protein expression was observed during pseudopregnancy, indicating that its expression is not embryo dependent. In other experiments, rabbit anti-ISP2 IgG was infused into the mouse uterine lumen on Day 3 or 4 of pregnancy to examine its effects on embryo implantation, whereas vehicle (saline) or unspecific rabbit IgG served as controls. The mean number of implanted embryos from anti-ISP2-IgG-treated mice was significantly lower than that from control mice. These results suggest that ISP2 may play an important role during embryo implantation.

Animals↗

PubMed2003

Synthetic studies on nonthrombogenic biomaterials 14: synthesis and characterization of poly(ether-urethane) bearing a Zwitterionic structure of phosphorylcholine on the surface.

A new Zwitterionic compound of the phosphorylcholine analogue, 4-hydroxylbutyl phosphorylcholine (HBPC), was synthesized and characterized. HBPC was chemically tethered onto the surface of poly(ether-urethane) (PEU) films with hexamethylene diisocyanate (HDI) as a coupling agent. The existence of a phosphorylcholine structure on the PEU surface was demomstrated by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FT-IR), X-ray photoelectron spectroscopy (XPS) and water contact angle measurements. The nonthrombogenicity of the modified films was evaluated by platelet-rich plasma (PRP) assay. The results showed that films grafted with HBPC have excellent platelet adhesion resistance.

Biocompatible Materials↗

PubMed2001

[The influence of tissue engineered tendon on subgroup of T lymphocytes and its receptor in roman chickens].

OBJECTIVE: To investigate the influence of tissue engineered tendon on subgroup of T lymphocytes and its receptor in Roman chickens. METHODS: The flexor digitorum profundus of the third toes of right feet in 75 Roman chickens were resected and made 2.5 cm defects as experimental model. They were randomly divided into five groups according to five repair methods: no operation (group A), autograft (group B), fresh allograft (group C), polymer combined with allogenous tendon cells (group D), derived tendon materials combined with allogenous tendon cells (group E). The proliferation and transformation of lymphocytes and contribution of CD4+, CD8+, CD28 and T cell receptor (TCR) were detected to study the immune response. RESULTS: The CD4+, CD8+ and TCR of group D and E were increased slightly than that of group B after 7 days, while after 14 days, those data decreased gradually and no significant difference between tissue engineered tendon and autografts (P > 0.05), and there was significant difference between fresh allograft and tissue engineered tendon (P < 0.05). Lymphocytes transformation induced by conA also showed no significant difference between tissue engineered tendon and autografts (P > 0.05). CONCLUSION: Tendon cells are hypoantigen cells, there are less secretion of soluble antigen or antigen chips dropped out from cells. Tissue engineered tendon has excellent biocompatibility.

Animals↗

PubMed2001

[Proliferation properties and telomerase activity of human embryonic tendon cells transformed by ptsA58H plasmid].

OBJECTIVE: To analysis the proliferation properties and telomerase activity of human embryonic tendon cells transformed by ptsA58H plasmid cultured in vitro continuously. METHODS: The 40th, 70th, and 75th passages of transformed human embryonic tendon cells (THETC) were adopted. The collagen secretion of THETC was detected by immunohistochemical methods, the growth curve of different passages of THETC was compared, and chromosome karyotype was analyzed. Total RNA of THETC were extracted to detect human telomerase reverse transcriptase (hTERT) mRNA expression by RT-PCR technique. RESULTS: When THETC were subcultured to 70 passages, the morphological characteristics of cells changed and began replicative senescence. THETC still could secret type I collagen normally. The chromosome of THETC was heteroploid (2n = 94). There were no hTERT mRNA expression. CONCLUSION: SV40 transfection can not make human embryonic tendon cells immortalization, on the other hand, human embryonic tendon cells transformed by ptsA58H plasmid has no tendency of malignant transformation.

Cell Division↗

PubMed2001

[Cellular compatibility of three natural xenogeneic bone derived biomaterials].

OBJECTIVE: To evaluate the cellular compatibility of three natural xenogeneic bone derived biomaterials. METHODS: Three types of natural xenogeneic bone derived biomaterials were made with physical and chemical treatment, composite fully deproteinized bone(CFDB), partially deproteinized bone(PDPB) and partially decalcified bone(PDCB). Three types biomaterials were cocultured with human embryonic periosteal osteoblasts. The cell growth, attachment, cell cycle, alkaline phosphatase activity were detected to evaluate the cellular compatibility to biomaterials. RESULTS: Osteoblasts attached on all three biomaterials and grew well, the effect of three biomaterials on cell proliferation was PDCB > PDPB > CFDB. The cell cycle was not obviously affected by three biomaterials. The effect of three biomaterials on alkaline phosphatase activity of osteoblasts was PDCB > PDPB > CFDB. CONCLUSION: CFDB,PDPB,PDCB have good cellular compatibility without cytotoxic and tumorigenicity, CFDB is the best. The three biomaterials can be used as scaffold materials of bone tissue engineering.

Bone Substitutes↗

PubMed2001

Ability of Agrogyron elongatum to accumulate the single metal of cadmium, copper, nickel and lead and root exudation of organic acids.

Agrogyron elongatum were grown in nutrient solution containing moderate to high amounts of separate heavy metal of Cd, Cu, Ni and Pb in a greenhouse for a 9-day. Cd, Cu, Ni and Pb generally led to decrease in the elongation of roots although the length of seedlings exposed to Cd and Pb at 0.05 and 0.5 mg/L showed to be slightly greater than that of controls. Of the four metals in the experiment, Pb was absorbed and accumulated to the highest level, with the concentrations of 92,754 mg/kg dry weight (DW) in roots and 11,683 mg/kg DW in shoots. Cd was moderately accumulated in Agrogyron elongatum, but the maximum bioaccumulation coefficients (BCs) for roots and shoots were observed. The patterns for Cu and Ni uptake and distribution in plants differed from those of Pb and Cd, as it was showed that the shoot accumulation of Cu and Ni was significantly higher than in roots. A. elongatum had the highest Ni concentration in shoots (30,261 mg/kg DW) at the external concentration of 250 mg/L. Cu ranked second, with a shoot concentration of 12,230 mg/kg DW when 50 mg/L Cu in solution was applied. For the four trace elements tested, the highest concentrations in shoots decreased by the order of Ni > Cu > Pb > Cd (mg/kg DW), and those in roots were Pb > Cd > Ni > Cu (mg/kg DW). Malic, oxalic and citric acids exuded by roots exposed to 1 and 50 mg/L of the metals were detected. Release of organic acids from plants significantly differed among the metal treatments. Cu was most effectively in inducing root exudation of the three types of organic acids. Cd, and Ni were also the inducers of secretion of malic and oxalic acids. With reference of Pb, a small amounts of malic and oxalic acids were detected in the root exudates, but few quantities of citric acid were found. However, no correlation between alternations in root exudation of organic acids and metal accumulation could be established.

Cadmium↗

PubMed2001

[Molecular tagging of a major powdery mildew resistance gene MlG in wheat derived from wild Emmer by using microsatellite marker].

Powdery mildew caused by Erysiphe graminis f. sp. tritici is one of the most important wheat diseases in many regions of the world. Breeding for resistant cultivars has been proved to be an effective and environmentally safe method to control diseases in wheat production. It is necessary to search for more resistance genes for the diversification of resistance genes in wheat breeding. An Isreali wild emmer wheat (Triticum dicoccoides) accession "G-305-M" was found resistant to the prevailing E. graminis f. sp. tritici isolate Race No. 15 in Beijing region. The powdery mildew resistance has been transferred from G-305-M into common wheat by crossing and backcrossing (G-305-M/781//Jing 411* 3). Genetic analysis showed that the resistance was controlled by a single dominant gene at the seedling stage. A segregating BC2F3 family of the cross "G-305-M/781//Jing 411* 3" with 167 plants was chosen for SSR analysis. Totally 96 wheat microsatellite primer pairs were screened, only one primer pair WMS570 could generate polymorphic DNA fragments between the resistant and susceptible plants. After evaluating this polymorphic marker in the segregating population, the microsatellite locus Xgwm570 mapped on chromosome 6AL was found to be linked to the resistance gene, with the estimated genetic distance of 14.9 +/- 3.0 cM. Based on the origin and chromosomal location of the gene, it is suggested that the resistance gene derived from G-305-M should be a novel Pm gene and is temporarily designated MlG.

Chromosome Mapping↗

PubMed2001

[The proliferation and differentiation of primary human embryonic skeletal myoblasts].

OBJECTIVE: To observe the proliferation and differentiation properties of primary human embryonic skeletal myoblasts cultured in vitro. METHODS: The skeletal muscle samples were obtained from 20 to 25-week abortion fetus, the family history of inherited myopathies of parental generation was negative. With a modified method of Blau, the muscle sample was digested with trypsin and collagenase. The isolated cell suspension was a mixture of myoblasts and fibroblasts, the latter was removed by repeated attachment to culture dishes. The morphological, immunohistochemical observation, the proliferation and differentiation of primary myoblasts were studied. RESULTS: The isolated myoblasts were spherical in cell suspension and spindle-like after attached to culture dishes. The myosin specialized immunohistochemical staining was strongly positive. A large quantity of skeletal muscle specialized creatine kinase (CK-MM) was synthesized in cultured myoblasts. Additionally, while the cell density of myoblasts increased, the monocyte myoblasts would fused to form multinucleated myotube. All those indicated that the cultured cells were myoblasts. Primary myoblasts proliferated quickly, the doubling time, measured in growth curve, was 4.8 days. CONCLUSION: A large number of myoblasts can be available with digestion and repeated attachment method. The cultured cells can be proved as myoblasts by morphological and immunohistochemical detection. The cultured myoblasts have good ability of proliferation and differentiation.

Animals↗

PubMed2001

[Advance on repair of growth plate injury].

OBJECTIVE: To sum up the studying course and latter development of repair of injury of growth plate. METHODS: Recent original articles about repair of injury of growth plate were extensively reviewed, focused on the progresses in understanding repair of injury of growth plate and comparison of several major reparative methods. RESULTS: Repair of injury of growth plate is a great difficulty in experimental study and clinical treatment of pediatric orthopedics. Graft of free growth plate and cartilage were unfavorably used because of lack of blood supplement. Although graft of vascularized growth plate solved circulation problem, both two kinds of grafts were involved in limitation of donor and immunologic reaction. Non-cartilaginous tissue and material could only prevent formation of bony bridge in small defect of growth plate and lacked ability of regenerative repair. Transfer of tissue engineered cartilage might be the best choice for repair of injury of growth plate. CONCLUSION: Considering source of transplanted material, reparative effect and adverse reaction, repair of injury of growth plate with tissue engineered cartilage deserves further investigation.

Adipose Tissue↗

PubMed2001

[Allogeneic humeral shaft transplantation with vascular anastomosis: twenty years follow-up].

OBJECTIVE: To sum up the clinical results of allogeneic humeral transplantation with vascular anastomosis, and evaluate the clinical significance. METHODS: From September to November 1979, 1 case with humeral shaft defect of 10 cm in length and 2 cases with tibia shaft defect of 12 cm in length were repaired by allogeneic humeral transplantation with vascular anastomosis. Azathiopurine and prednisone were applied for 3 months postoperatively. All cases were followed up for 20 years. RESULTS: Case 1 recovered well with good bone union and reconstruction after operation, and could work normally. In case 2, five chronic rejections were occurred during 3 years after operation, and recovered after treatment, the allograft bone was fractured after 2 years of operation, and unioned by autogeneous iliac bone transplantation. In case 3, the distal part of allograft bone was fractured after 46 months, and unioned by autogeneous iliac bone transplantation. The middle part of allograft bone was non-unioned after 20 years follow-up in case 3, but the patient could still work normally. CONCLUSION: The clinical results of allogeneic long bone transplantation can be improved by rational tissue matching test, application of effective immunosuppressive drugs in a certain period according to the principles of modern transplantation immunology.

Adolescent↗

PubMed2001

[Studies on preparation of herba epimedii total flavonoids phytosomes and their pharmaceutics].

OBJECTIVE: To optimize preparation techniques for Herba Epimedii flavonoid phytosomes (EFP) and explore their suitable pharmaceutics. METHODS: To optimize the preparation conditions by means of uniform design and step regression, prepare Herba Epimedii total flavonoid phytosomes by means of solvent evaporation and investigate the accumulative dissolution of different ratios of EFP-PVP precipitates by means of dissolution release. RESULT: The optimized preparation conditions are as follows: solvent-tetrahydrofuran, lecithin to PVP--2.5 times, temperature--40 degrees C and reaction--3 hours. Oil/water apparent partition coefficient of icariin was enhanced more than 4 times by phospholipid. The accumulative dissolution of Herba Epimedii flavonoids of EFP-PVP precipitate was significantly higher than that of its physical mixture and Herba Epimedii extract tablet. CONCLUSION: Phospholipid can effectively enhance the oil/water apparent partition coefficient of icariin, and PVP can improve the dissolution of Herba Epimedii phytocomes, but the pharmacokinetics needs further study.

Capsules↗

PubMed2001

[Repair of growth plate defects of rabbits with cultured cartilage transplantation].

OBJECTIVE: To prevent early closure of growth plate and developmental deformities of limbs by allografts of cultured cartilages into growth plate defects of rabbits. METHODS: Chondrocytes isolated from articular cartilage of 1-month rabbits formed cartilage after cultivation in centrifuge tubes. The cartilages cultured for two weeks were implanted into growth plate defects of proximal tibiae of 6-weeks rabbits. At 4th and 16th weeks, X-ray, histologic and immunohistochemical examination were performed. RESULTS: The tibiae had no marked deformities after 4 weeks of operation. Histologic examinations showed that the defects were filled with cartilage. Immunohistochemical results of type II collagen were positive. The tibiae with allografts of cultured cartilages had no evident deformities after 16 weeks of operation. Histologic examination showed nearly closure of growth plates. On the contrary, the tibiae on control side formed severe deformities and growth plate were closed. CONCLUSION: Allograft of cultured cartilages into growth plate defects may replace lost growth plate tissues, maintain normal growth of limbs and prevent developmental deformity.

Animals↗

PubMed2000

Evaluation on sperm quality of freshly ejaculated boar semen during in vitro storage under different temperatures.

The purpose of this study was to assess the sperm quality of fresh ejaculated boar semen stored under different temperatures for up to 48 h in order to use the fresh semen efficiently. Spermatozoa were evaluated by 4 methods: Using trypan blue staining, the viability of spermatozoa stored at 39, 20, 15 and 4 degrees C for 48 h were 1.6, 46.9, 42.0 and 31.0%, respectively. Employing the hypoosmotic swelling test (HOST) showed 1.7%(39 degrees C), 28.7%(20 degrees C), 24.1%(15 degrees C), and 20.1%(4 degrees C) coiled-tail spermatozoa following 48 h storage. With Coomassie blue staining, the rates of acrosome-intact spermatozoa stored for 48 h were 4.5%(39 degrees C), 35.3%(20 degrees C), 55.7%(15 degrees C) and 22.8%(4 degrees C). Using fluorescein isothiocyanate-peanut agglutinin (FITC-PNA), the percentages of acrosome-intact spermatozoa stored for 48 h were 4.3%(39 degrees C), 43.2%(20 degrees C), 17.3%(15 degrees C) and 14.8%(4 degrees C), respectively. The cytoplasmic droplets were found in 18.66% of the spermatozoa in fresh semen and were gradually shed during storage. The results of these 4 methods were highly correlated and could be used to characterized sperm-cell quality effectively. These findings indicated that both membrane integrity and viability of spermatozoa could be preserved well during in vitro storage at 20 degrees C and 15 degrees C for 24 to 48 h.

Animals↗

PubMed2000

Epidermal growth factor family in rhesus monkey uterus during the menstrual cycle and early pregnancy.

This study examines immunohistochemically the presence of EGF, TGFalpha, HB-EGF, AR, and EGFR, members of the EGF family in the monkey uterus during the menstrual cycle and early pregnancy. EGF, TGFalpha, HB-EGF, AR, and EGFR were mainly localized in glandular and luminal epithelium. TGFalpha, HB-EGF, and AR staining were stronger in the glandular epithelium closer to the myometrium than in that closer to the luminal epithelium. The level of EGF, TGFalpha, HB-EGF, AR, and EGFR staining was low on days 1 and 6, and began to increase on day 9 of the menstrual cycle. A high level of EGF, and EGFR staining was maintained on days 16, 20, and 25 of the menstrual cycle. The highest levels of TGFalpha, AR, and HB-EGF staining were seen on days 16 and 20 of the menstrual cycle. In early pregnancy, a low level of EGF, TGFalpha, HB-EGF, AR, and EGFR staining appeared on days 1 and 2 of pregnancy, and then gradually increased from day 3 of pregnancy. The highest levels of EGF, TGFalpha, HB-EGF, and EGFR were detected on days 9, and 11 of pregnancy. Our data suggest that the EGF family may play a role in monkey implantation. Mol. Reprod. Dev. 55:164-174, 2000.

Amphiregulin↗

PubMed2000

Effects of platelet activating factor on capacitation and acrosome reaction in mouse spermatozoa.

Platelet activating factor (PAF) plays an important role in mammalian reproduction. The aim of this study was to investigate the effects of PAF on capacitation and acrosome reaction of mouse spermatozoa by chlortetracycline (CTC) fluorescence assay and coomassie blue staining. The percentage of capacitated mouse spermatozoa was increased (P < 0.05) by incubation with 50 ng/ml PAF for 20-120 min. The peak response occurred between 80 to 100 min of exposure to PAF. In contrast, the effects of PAF on acrosome reaction may be not receptor-mediated since lyso-PAF had the same effects. Ionophore A23187 stimulated an increase in acrosome-reacted spermatozoa of PAF-treated spermatozoa, but not of lyso-PAF-treated ones. These results suggest that PAF mainly acts on sperm capacitation.

Acrosome Reaction↗