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Biomedical subjects

Z M Yang

Publications and source records attributed to Z M Yang.

At least 37 records · Page 2Linked to original sources
PubMed2000

Leukemia inhibitory factor, leukemia inhibitory factor receptor, and glycoprotein 130 in rhesus monkey uterus during menstrual cycle and early pregnancy.

This goal of this study was to examine immunohistochemical distribution of leukemia inhibitory factor (LIF), LIF receptor (LIFR), and glycoprotein (gp) 130 in rhesus monkey uterus during the menstrual cycle and early pregnancy. Pregnancy rate was significantly reduced in the control group from 66.7% (12 of 18) to 22.2% (4 of 18) with an injection of goat anti-human recombinant LIF immunoglobulin G into the uterine lumen on Day 8 of pregnancy. LIF was mainly localized in glandular and luminal epithelium. LIF immunostaining during the luteal phase was stronger than it was during the proliferative phase. LIF staining gradually increased from Day 3 of pregnancy and reached its highest level on Day 9. LIFR was mainly localized in the glandular and luminal epithelium. LIFR staining during the luteal phase was stronger than it was during the proliferative phase. LIFR staining began to increase from Day 3 of pregnancy and reached a high level on Days 9 and 11. Gp130, a signal-transducing receptor component of LIF, was mainly localized in the glandular epithelium. A high level of gp130 was found on Days 16 and 20 of menstrual cycle, and from Days 5 to 11 of pregnancy. These results suggest that LIF may play an important role in monkey implantation, as it does in mice.

Animals↗
PubMed2000

Aluminum tolerance genes on the short arm of chromosome 3R are linked to organic acid release in triticale.

Triticale, a hybrid between wheat and rye, shows a high degree of Al tolerance that is inherited from rye, but the mechanisms of high Al tolerance in both rye and triticale are unknown. We found that the short arm of chromosome 3R carries genes necessary for Al tolerance in triticale (x Triticosecale Wittmark cv Currency). Detailed comparative studies with a 3DS.3RL translocation line (ST22) and a non-substitution line (ST2) were conducted. Root elongation was similarly inhibited by Al in ST2 and ST22 during the first 12 h of Al treatment, but more strongly in ST22 than in ST2 at 18 h and thereafter. The root inhibition induced by other metals (Cu, Cd, and La) was similar between ST2 and ST22, suggesting that the action of the genes for Al tolerance on the short arm of triticale chromosome 3R is highly specific to Al. A 2-fold larger amount of malate and citrate was released from the roots of ST2 than from ST22 at 12 and 18 h after Al treatment, respectively. The marked lag phase in the inhibition of root elongation and the release of organic acids implies that the expression of genes on the short arm of triticale chromosome 3R is induced by Al, and that these genes are necessary for the release of organic acids.

Acids↗
PubMed2000

[Expression of type I collagen and its receptor system in osteoblasts].

OBJECTIVE: To study the expression of type I collagen and its receptor system-integrin alpha 2 beta 1 in different passages of osteoblasts. METHODS: The expression of type I collagen and integrin alpha 2 beta 1 in the primary, sixth and fifteenth passage of osteoblasts were detected by S-P immunohistological staining technique, and their mRNA expression by quantity RT-PCR technique. RESULTS: Type I collagen and integrin alpha 2 beta 1 were expressed in different passages of osteoblasts and there was no significant difference among three passages by immunohistological technique. Their mRNA expression was gradually decreased with subculture. CONCLUSION: Type I collagen promotes the adhesion and phenotype expression of osteoblasts through its receptor-integrin alpha 2 beta 1. The reductive expression of type I collagen-receptor system will decline the phenotype of osteoblasts.

Cells, Cultured↗
PubMed2000

[Short tandem repeat loci examination after repair of coracoclavicular ligament injury by tissue engineered tendon].

OBJECTIVE: To evaluate the result of clinical application in the repair of coracoclavicular ligament injury by tissue engineered tendon using the technique of short tandem repeat loci examination. METHODS: In september 1999, human embryonic tendon cells and artificial materials were co-cultured in vitro to construct tissue engineered tendon, which repaired coracoclavicular ligament injury. After 6 months of operation, micro-tissue were sampled during the operation of removal of internal fixation, and morphological characteristics were examined by HE staining, DNA of tissues were extracted to examine D3S1754 and Cyar04 gene loci. RESULTS: The shoulder function of the patient was recovered well after operation, and no local or systemic immunological rejection were occurred. The electrophoresis typing showed 13/14 at D3S1754 and 8/9 at Cyar04 in the tissue of tissue engineered tendon, while the autogenous ligament were 13/13 and 8/8 at D3S1754 and Cyar04 loci respectively, which suggested that the tissue engineered tendon was survived in vivo. CONCLUSION: The examination of short tandem repeat loci is a better index to evaluate the survival situation of tissue engineered tissue after transplantation in clinical application.

Acromioclavicular Joint↗
PubMed2000

[SV40 and cell immortalization].

OBJECTIVE: To explore the SV40-mediated immortalization, the related factors and their roles in cell immortalization. METHODS: The original articles about cell immortalization and replicative senescence in recent decade were reviewed. RESULTS: Cell immortalization was a multifaceted phenomenon, it was involved in viral DNA integration, activation of telomerase, inactivation of growth suppressors, and so on, and their roles were closely related. CONCLUSION: The research on cell immortalization may be expected to provide important insights into a broad range of cellular biological phenomenon, and the immortalized cells can play important roles in the research of cell engineering and tissue engineering as standard cells.

Animals↗
PubMed2000

[Huge thoracic wall defect repaired by tissue engineered bone transplantation].

OBJECTIVE: A rare huge desmoplastic fibroma on thoracic wall in 1 female case of 25 years old was resected, and the accompanying huge thoracic wall defect, ribs and soft tissues were repaired by tissue engineered bone and pedicled flap. The paper aims to explore the clinical results of early stage after operation. METHODS: Autogeneic bone marrow stromal cells (MSC) were obtained from bone marrow puncture of iliac bone and isolated and cultured according to the Houghton's methods, MSC were directively induced and differentiated to osteoblasts. Allogeneic ribs were made to the bio-derived bone scaffold materials after treatment of decell, deantigen, decalcification and dry freezing. 5 x 10(6)/ml MSC were cocultured with the bio-derived bone for 6 days in vitro. After intact resection of tumor, the diaphragm flap was applied to repair pleural cavity, the three defect ribs were repaired by tissue engineered bone and the soft tissue defect was repaired by transfer of pedicled ipsilateral abdominal flaps. RESULTS: The patient recovered well with first intention. Followed up for 3 months, tissue engineered ribs were matured in vitro and the heart and pulmonary functions were improved markedly. CONCLUSION: The tissue engineered bone constructed by autogeneic MSC is advantageous in individual treatment.

Adult↗
PubMed2000

[Biological characteristics of continuously subcultured human embryonic skeletal myoblasts].

OBJECTIVE: To investigate the biological characteristics of continuously subcultured human embryonic skeletal myoblasts, and choose the optimal seeding cells for muscle tissue engineering. METHODS: Human embryonic skeletal myoblasts were subcultured in vitro. The growth curve, rate of myotube formation(RMF) were used to evaluate the proliferative and differentiation ability of myoblasts, and to investigate the influence of fibroblasts contamination on myoblasts. RESULTS: The beginning 6 passages of myoblasts showed strong proliferative and differentiation ability. From the 8th to 20th passage, the rate of fibroblasts contamination was increased, it mainly showed the growth characteristics of fibroblasts with increased proliferation and low differentiation. After subcultured to the 20th passage, the degeneration of myoblasts was obvious. CONCLUSION: The myoblasts within 6 passages should be used as the seeding cells of muscle tissue engineering because of strong proliferative ability and high rate of myotube formation.

Cell Division↗
PubMed2000

[The development of an intellectualized dynamic strain device for three-dimensional cell culture].

The design principles of an intellectualized dynamic strain device for three-dimensional cell cultures based on microcomputer are mainly introduced here, which includes principles of hardware and software design of controlled unit, principle and structure of mechanical unit, and construction of three dimensional scaffold and culture unit. The main technical index and advantages of the device have been also discussed in the paper.

Artificial Intelligence↗
PubMed1999

[Comparative study of the late results between two types of operations in the treatment of old derangement of distal radio-ulnar joint].

OBJECTIVE: To evaluate the clinical results of Darrach's procedure and Sauve-Kapandji's procedure in the treatment of old derangement of distal radioulnar joint. METHODS: Twenty-three patients with old derangement of distal radioular joint were divided into two groups, in which 11 patients received resection of distal end of ulna by Darrach's procedure and 12 patients received pseudoarthrosis operation of the distal ulna by Sauve-Kapandji's procedure. RESULTS: Fifty-six months after Darrach's procedure, complete relief of pain was obtained in 6 cases (P < 0.01), the flexion-extension movement improved from 104 degrees to 125 degrees (P < 0.01), rotation movement of the forearm improved from 106 degrees to 128 degrees (P < 0.01) and grippig strength improved from 17 kg to 28 kg (P < 0.01). Fifty-five months after Sauve-Kapandji's procedure, complete relief of pain was obtained in 9 cases (P < 0.01), the movement flexion-extension improved from 108 degrees to 126 degrees (P < 0.01), rotation movement of the forearm improved from 101 degrees to 135 degrees (P < 0.01) and grippig strength improved from 17 kg to 35 kg (P < 0.01). CONCLUSION: 1. The two operation showed no difference in relief of the wrist pain, improvement of the movement of the wrist and that of the forearm; 2. Sauve-Kapandji's procedure was superior to Darrach's procedure in increasing gripping strength; and 3. So the Sauve-Kapandji's procedure was superior to Darrach's procedure, especially in the long-term result, in the treatment of old derangement of the distal radioulnar joint.

Adult↗
PubMed1999

[Culture of the transformed human embryonic tendon cells and its biological characteristics in vitro].

OBJECTIVE: This paper was to study the biological characteristics of the transformed human embryonic tendon cells, the relation between cell growth and culture conditions, and to compare these features with that of human embryonic tendon cells. METHODS: The pts A58H plasmid had successfully used to transform a tendon cell line from human embryo in our past work. The human embryonic tendon cells and the transformed human embryonic tendon cells were cultured in vitro. In different culture conditions, the growth curve were drawn respectively. Population dependence and proliferation capability of the cells were investigated through plate cloning test and soft agar culture. The collagen secreted by cells was identified by immunohistochemical method. RESULTS: In routine culture condition, the growth properties of the human embryonic tendon cell and transformed cells were almost identical. The growth properties of the transformed cells were not changed when the cells were frozen storage. There were changes of growth characteristics of the transformed cells when the culture temperature was changed. The transformed cells could subcultured continually and permanently. The proliferation capability of the transformed cells were stronger than that of the human embryonic tendon cells. Moreover, the growth of the transformed cells was serum-dependent, and the phenomenon of contact inhibition was observed. The transformed cells were not able to grow on soft agar culture. They had the capacity of secreting collagen type I. CONCLUSION: The transformed human embryonic tendon cells could be subcultured continually and permanently, and their growth could be controlled by changing their culture conditions and they had no malignant tendency in biological characteristics. They could be taken as an ideal experimental material for tendon engineering.

Cell Division↗
PubMed1999

[A review on the application of myoblast on gene therapy and tissue engineering].

OBJECTIVE: Because of its special biological characteristics, myoblast might play a role in gene delivery and cell-to-biomaterial interactions. In this paper, the biological features of myoblast and its application on gene therapy and tissue engineering was discussed. METHODS: Documents about proliferation and differentiation of myoblast were reviewed in details. The prospects of its application on gene therapy and tissue engineering were also presented. RESULTS: Myoblast was important in muscle regeneration. The activation of myoblast to proliferate and differentiate was the very beginning of regeneration after injury. The cultured myoblast had high potential to proliferate, it was ready to fuse with each other and to form myotube (the special behavior of myoblast differentiation). Myoblast transplantation had been studied as a possible treatment for inherited myopathies, such as Duchenne muscular dystrophy. The transplanted myoblast could fuse with host myofibers, so the delivered target gene integrated into host. Several myoblast-mediated gene delivery system had been established, including the gene delivery of human factor IX (hFIX), erythropoietin (EPO) and clony stimulating factor-1 (CSF-1). Results from animal experiments demonstrated that myoblast-mediated gene delivery could be used as gene therapy for some inherited diseases. And recently, some authors have shown great interest in the interaction between myoblast and type I collagen gels. It was found that myoblast could keep on proliferating and differentiating in collagen gels and could form discoid, tubular materials. CONCLUSION: Myoblast has great importance in gene therapy and tissue engineering. It is suggested that more efforts should be made in this field.

Cell Transplantation↗
PubMed1999

[Review on transformed cell and tumorigenicity].

OBJECTIVE: To explore the relationship between characteristics of transformed cell and tumorigenicity. METHODS: Documents about transformed cell and tumorigenicity were reviewed in detail. RESULTS: Normal biological characteristics and cell function could be maintained in non-tumorigenic transformed cell, but it was changed markedly in malignant transformed cell. CONCLUSION: Non-tumorigenic transformed cell can be served as a standard cell line to study the function and growth characteristics of normal cell.

Animals↗
PubMed1999

[Direct and indirect recognition in pig-to-man xenotransplantation].

OBJECTIVE: To investigate the role of direct and indirect recognition in pig-to-man xenotransplantation. METHODS: Taken the peripheral blood lymphocytes (PBLC) from three Neijiang pigs and two humans as stimulators and respondors, the one-way mixed lymphatic reactions (MLR) of xenograft were carried out, and allo- and self-PBLC as control. RESULTS: Among the three patterns of MLR, syngeneic was MLR the lowest in proliferation, the allogenic MLR was the highest, and the xenogenic MLR was medium. The PBLCs from humans and pigs were matched on HLA-A, B, DR and DQ by means of modified Terasaki assay. The match on pigs was failure because of the pre-existing natural xenogenic antibody in the testing serum. CONCLUSION: The results suggest that the degree of MHC matching still affect the rejection in xenotransplantation, but the present serum assay of MHC matching is not fit for pig.

Animals↗
PubMed1997

Potential sites of prostaglandin actions in the periimplantation mouse uterus: differential expression and regulation of prostaglandin receptor genes.

Prostaglandins (PGs), especially PGE2 and PGF2alpha, are considered important for blastocyst spacing, implantation, and decidualization in the rodent uterus. However, information regarding uterine sites of PG actions in these processes is lacking. PGE2 or PGF2alpha interacts with specific G protein-coupled membrane receptors. PGE2 receptors are classified into four subtypes, EP1, EP2, EP3, and EP4. While EP1 is coupled to Ca2+ mobilization, activation of EP2 and EP4 triggers stimulation of adenylyl cyclase. In contrast, activation of EP3 inhibits adenylyl cyclase. PGF2alpha receptor (FP) is coupled to stimulation of phospholipase C-inositol trisphosphate (IP3) pathway and Ca2+ mobilization. This investigation demonstrates that PGE2 and PGF2alpha receptor genes are expressed in a temporal and cell-specific manner in the periimplantation mouse uterus. In the mouse, the attachment reaction occurs in the evening (2200-2300 h) of Day 4 of pregnancy and is preceded by embryo spacing, uterine edema, and luminal closure resulting in an intimate apposition of the blastocyst with the uterine luminal epithelium. Expression of EP3 and FP primarily in the circular muscle of the myometrium on Days 3-5 of pregnancy suggests that the circular muscle, not the longitudinal muscle, is the primary target for PG-mediated uterine contractions required for embryo transport, spacing, and/or accommodation in the uterus. In contrast, expression of EP3 in a subpopulation of cells in the stromal bed at the mesometrial side, and of EP4 in the epithelium and stroma on these days, suggests that PGE2 effects on uterine preparation for implantation (such as epithelial cell differentiation, stromal cell proliferation, uterine edema, luminal closure, and increased localized endometrial vascular permeability at the sites of blastocyst attachment) are mediated by these receptor subtypes. Similar expression patterns of EP3 and EP4 in the Day 4 pseudopregnant mouse uterus or in the ovariectomized uterus under combined treatment with estrogen and progesterone suggest that these genes are regulated by ovarian steroids rather than by the embryo during the preimplantation period (Days 1-4). In contrast, the expression of these genes during the postimplantation period (Days 5-8) is associated with the onset of decidualization.

Animals↗
PubMed1997

Risk of relapse in leprosy after fixed-duration multidrug therapy.

Between 1986 and 1995, 8307 leprosy patients have completed fixed-duration multidrug therapy (FD-MDT) and were followed annually for possible relapse. The mean relapse rate for multibacillary (MB) leprosy is 0.15/1000 person-years (py) and for paucibacillary (PB) 0.55/1000 py. There is no difference in the relapse rates between patients with or without chemotherapy before FD-MDT. In MB patients, the five relapses occurred between 4 and 7 years; in PB patients, five relapses occurred at 4-5 years after FD-MDT. Six additional PB relapses self-reported 1-4 years after the 5-year surveillance period and were not included in the relapse rates. Most PB patients relapsed into MB due to wrong classification and insufficient therapy. For the known 62 irregular MB patients the cumulative relapse rate is 6.5%.

Anti-Infective Agents↗
PubMed1996

Differential hormonal regulation of leukemia inhibitory factor (LIF) in rabbit and mouse uterus.

Leukemia inhibitory factor (LIF) has been shown to be essential for the implantation of mouse blastocysts. The present study was designed to determine how LIF protein was hormonally regulated in rabbit and mouse uterus using immunohistochemistry. In unmated rabbits, LIF protein was at a low level in the uterine epithelium and glands, and up-regulated by progesterone alone or estradiol-17 beta and progesterone combined. Estradiol-17 beta alone had no apparent effect. In ovariectomized mice, the level of LIF protein was very low in the uterine epithelium and glands, and was up-regulated by estradiol-17 beta alone or estradiol-17 beta and progesterone combined. Progesterone alone had no apparent effect. These results suggest that LIF protein is differentially regulated in rabbit and mouse uterus by progesterone and estrogen, respectively. This would explain the high level of LIF protein observed in uterine epithelium and glands prior to blastocyst implantation in the two species with different hormonal requirements for implantation.

Animals↗
PubMed1996

Activation of brain-type cannabinoid receptors interferes with preimplantation mouse embryo development.

The recent identification and cloning of guanine nucleotide regulatory protein-coupled brain-type and spleen-type cannabinoid receptors (CB1-R and CB2-R, respectively) provide evidence that many of the effects of cannabinoids are mediated via these receptors. Our recent observation of expression of both CB1-R and CB2-R genes in the preimplantation mouse embryo suggests that it could also be a target for cannabinoids. Indeed, cannabinoid agonists interfered with preimplantation embryo development in vitro. To examine whether cannabinoid effects on preimplantation embryos are mediated via CB1-R, we developed rabbit antipeptide antibodies against the N-terminal region of CB1-R and examined the receptor protein in the blastocyst by Western blotting and its spatiotemporal distribution in preimplantation mouse embryos by immunohistochemistry. Cannabinoid binding sites in the blastocyst were examined by Scatchard analysis, while the reversibility of cannabinoid-induced embryonic arrest in vitro was monitored using a specific antagonist to CB1-R, SR141716A. Western blot analysis detected a major band of approximately 59 kDa and a minor band of approximately 54 kDa in the blastocyst. Immunocytochemistry detected this receptor protein from the 2-cell through the blastocyst stages. Scatchard analysis using 3H-anandamide (an endogenous ligand) showed a single class of binding sites in Day 4 blastocysts with an apparent Kd of 1.0 nM and Bmax of 0.09 fmol/blastocyst. Considering the total number of cells (approximately 50) and total protein content (approximately 20 ng) of a blastocyst, it is apparent that the mouse blastocyst has many more high-affinity receptors than those in the mouse brain (Kd: 1.8 nM and Bmax: 18.8 pmol/mg membrane protein). Cannabinoid agonists and the CB1-R antagonist SR141716A effectively competed for anandamide binding in the blastocyst. To determine whether cannabinoid inhibition of embryonic development could be reversed by SR141716A, 2-cell embryos were cultured in the presence of cannabinoid agonists with or without SR141716A for 72 h. Most of the 2-cell embryos cultured in the absence of the agonists developed into blastocysts (approximately 90%). In contrast, the addition of cannabinoid agonists anandamide, Win 55212-2, or CP 55,940 in the culture medium severely compromised embryonic development: more than 60% of the 2-cell embryos failed to develop to blastocysts. A reduction in trophectoderm cell numbers was noted in those blastocysts that escaped the developmental arrest in the presence of cannabinoid agonists. However, this reduction was corrected when embryos were cultured simultaneously with an agonist and SR141716A. Furthermore, embryonic arrest was reversed when embryos were cultured simultaneously in the presence of an agonist and SR141716A. The addition of SR141716A alone in the culture medium apparently had no effects on embryonic development: more than 90% of the embryos developed into blastocysts. The results suggest that the CB1 receptors in preimplantation mouse embryos are biologically active and cannabinoid effects on them are primarily mediated by these receptors.

Analgesics↗