Biomedical subjects

Y Wei

Publications and source records attributed to Y Wei.

At least 181 records · Page 10Linked to original sources

PubMed1999

Rat model of Achilles tendon disorder. A pilot study.

Three-month-old male rats were subjected 3 times weekly for 1 h to eccentric exercise of one triceps surae muscle (30 stimulations/min) under general anesthesia in order to induce Achilles tendon disorder corresponding to paratenonitis and tendinosis in man. Net muscle work during the sessions ranged between 0.67 and 4.37 mJ (mean 1.72, SD 0.77). After 9 and 13 sessions, respectively, 2 rats started to show gait alterations during the functional test which was performed 2-3 times weekly. These rats were killed after additional sessions which showed a worsening of the limp. The other trained rats and controls did not limp and were killed after 7-11 weeks. Histologic evaluation of the Achilles tendons from the exercised limb showed in the majority of the cases hypervascularization, increased number of nerve filaments and increased immunoreactivity for substance P and calcitonin gene-related peptide. The tendons from the nonstimulated limb looked normal. The distribution of collagen types I and II appeared normal in the tendon and its insertion to the calcaneus. Inflammation of the epi- and paratenon could be provoked in the rat, but tendon changes corresponding to chronic tendinosis did not develop within 11 weeks with the used training regime. The clinical relevance of this model for chronic tendon disease needs to be evaluated further.

Achilles Tendon↗

PubMed1999

Role of urokinase receptor and caveolin in regulation of integrin signaling.

Emerging evidence indicates a prominent role for non-integrin membrane adaptors in the dynamic regulation of integrin signaling. Two such integrin-associated proteins are the glycosylphosphatidyl-inositol (GPI)-linked urokinase receptor (u-PAR) and the cholesterol-binding protein, caveolin-1. Recent studies indicate that caveolin is required for the association of Src-family kinases with beta 1 integrins. Loss of caveolin/beta 1 integrin association results in loss of ligand-induced focal adhesion kinase (FAK) phosphorylation and impaired development of focal adhesion sites. Similarly, fibronectin-dependent fyn signaling through alpha 5/beta 1 leading to mitogen-activated protein (MAP) kinase activation requires the presence of caveolin-1. Caveolin binds Src-family kinases and such binding maintains these kinases in an inactive state. Current evidence favors a model in which ligand-induced integrin clustering, a central event in integrin activation, promotes caveolin oligomerization leading to release and/or activation of Src-family kinases and initiation of integrin signaling. The presence of u-PAR promotes these events because the extracellular domain(s) of u-PAR binds to beta 1 and beta 2 integrins and the GPI anchor of u-PAR, like that of other GPI-anchored proteins, interacts with cholesterol-rich membrane domains enriched in caveolin and tyrosine kinases. Integrins, caveolin, and u-PAR form interdependent functional complexes, promoting the association of integrins with caveolin-rich signaling domains. During states of accelerated cellular migration, such as during inflammation and tumorigenesis, expression of u-PAR may be a key facilitator of integrin signaling. Interruption of u-PAR/integrin interactions may be a strategy to regulate cellular migration in these settings.

Animals↗

PubMed1999

[Phorbol-12-myristate-13-acetate and interferon-gamma synergistic induction of B7-1 expression in ovary carcinoma cells and immunological value].

OBJECTIVE: To investigate the therapeutic potential of phorbol-12-myristate-13-acetate(PMA) and interferon-gamma(IFN-gamma) by induction of expression of adhesion molecule in mucious cystadenocarcinoma of ovary (MCAS) and other tumor cells. METHODS: Expression of costimulatory signals(B7-1), major histocompatibility complex(MHC-I, MHC-II) was analysed with flow cytometry. Cytotoxic T lymphocytes(CTL) killing activity and T cell proliferation induced with expression of B7-1 were evaluated by 4-h 51Cr release assay and standard 3HTdR incorporation and scintitation counting. RESULTS: Pretreatment with PMA and then treated with IFN-gamma was able to enhance B7-1 expression on the tumor cell lines with the constitutive B7-1 expression or on B7-1-transfected tumor cells and to induce B7-1 expression on MCAS and some tumor cell lines without constitutive B7-1 expression. However, treatment with IFN-gamma alone failed to induce B7-1 expression on the tumor cell lines. The synergistic effect of PMA combined with IFN-gamma in the induction of B7-1 expression can be anatagonised by H7 [1-(5-isoquinolinesulfonyl)-2-methyl-Piperazine dihydrochloride]. In addition, treatment with PMA combined with IFN-gamma simultaneously induced or enhanced the expression of MHC class I/II on these tumor cell lines. The tumor cells treated by PMA combined with IFN-gamma were able to induce CTL killing activity and T cell proliferation, which is involved in the expression of B7-1. CONCLUSIONS: The enhancement or induction of B7-1 expression by IFN-gamma may be dependent on the prior activation of protein kinase by PMA and the induced B7-1 expression on tumor cells may have some therapeutic potential.

B7-1 Antigen↗

PubMed1999

[Gene diagnosis of X linked retinitis pigmentosa by linkage analysis].

OBJECTIVE: To establish a gene diagnosis method for X linked retinitis pigmentosa (XLRP). METHODS: Ten microsatellite markers were selected from the region where the RP2 and RP3 gene may be located at Xp21.1-p11.23. Haplotype analysis for XLRP pedigrees was used to determine the chromosome region which is RP related and whether this region was carried by the individuals we want to detect. RESULTS: The young female who is the RP carrier or the young boy who is the pre-symptom RP patient could be determined this way in 4 XLRP family. CONCLUSION: Haplotype analysis for XLRP Pedigrees is useful.

Adult↗

PubMed1999

[Adenovirus-transferred antisense c-myc selectively induces tumor cell cycle arrest and apoptosis].

OBJECTIVES: To construct the recombinant adenovirus encoding antisense c-myc fragment and to investigate its effect on tumor cell proliferation and apoptosis. METHODS: The shuttle plasmid encoding antisense c-myc was constructed by cloning c-myc cDNA fragment in the reverse direction into the pAdCMV. Then the plasmid pJM17 and the shuttle plasmid were co-transferred into 293 cells with liposome for homologous recombination to acquire recombinant adenovirus. The cell cycle, apoptosis, and the expression of related genes of the in vitro transferred human adenocarcinoma cell lines GLC-82 and SPC-A-1, as well as the human embryonic diploid lung cell line 2BS were studied. The effects on colony formation and treating effect on transplanted tumor in nude mice were also studied. RESULTS: The recombinant adenovirus encoding antisense c-myc fragment was obtained with the titer of 3.3 x 10(10) pfu/ml. RT-PCR and Western blot showed that the expression of c-myc was reduced 3-5 days after infection. Simultaneously, obvious G1 arrest and apoptosis as well as the alteration of cyclin D1, bcl-2 and bax gene expression were observed in the infected tumor cells. The infected 2BS cells showed no such changes. The colony formation ability in vitro and the growth of the hetero-transplanted tumor in nude mice were also reduced. CONCLUSIONS: The reduced expression of c-myc gene could induce human adenocarcinoma cells tumor-cell-specific G1 arrest and apoptosis, while it has no effect on normal cell.

Adenocarcinoma↗

PubMed1999

[The effect of alginate purity on microencapsule overgrowth and function of microencapsulated hepatocyte in peritoneal transplantation].

OBJECTIVE: To study the effect of alginate purity on microencapsule overgrowth, histology and function of microencapsulated hepatocyte (MH). METHODS: Alginate was purified by filtration and chloroform/butanol extraction. Using purified and crude alginate to make two kinds of MHs, we transplanted each kind of MHs into the peritoneal cavities of rats. After 2 weeks, 1, 2 and 6 months, MHs were washed out to study overgrowth of MH, histology, and expression of enzyme and albumin in hepatocytes. Two kinds of MHs (the purified and the crude) were transplanted to FHF rats separately to study their differences in liver function support. RESULTS: The amount of retrieved MHs was larger in the purified than in the crude (P < 0.001). In the purified group, most hepatocytes had normal morphology, positive enzymatic histochemistry and albumin immuno-histochemistry stain in one month of transplantation but were damaged in the crude group only 2 weeks later. Microencapsules were smooth and no overgrowth was observed during 6 months in the purified but all overgrowth one month later after transplantation in the crude. The purified MHs had excellent liver function support in the FHF comparing with the crude and the control. CONCLUSION: The purified alginate may significantly reduce the overgrowth of MHs and improve the function of hepatocytes.

Alginates↗

PubMed1999

[In vitro and in vivo evaluation of the safety of Ad-RA538].

OBJECTIVE: To assess the safety of adenovirus-mediated transfer of the RA538 (Ad-RA538) for the treatment of cancer and to furthermore in preparation for a clinical trial of Ad-RA538. METHODS: RT-PCR was used to detect the transcription of Ad-RA538 in HeLa cells infected with extracts from HeLa cells previously infected with Ad5-RA538. Cell counting was made to observe the effects of Ad-RA538 on the growth of the normal human fetal lung cell line 2BS. The virus was intraperitoneally injected into 2 groups of BalB/C mice at a dosage of 10(7) pfu and 10(9) pfu. Blood samples were taken from the mice to test the liver and renal function. PCR were used to screen the vital organs for the presence of adenovirus DNA. Microscopic examination of the vital organs was performed to observe the pathogenicity of Ad-RA538. RESULTS: Ad-RA538 was a replication-defective virus. It could infect 2BS cells effectively, but could not inhibit 2BS cell growth. No mouse died and no signs of general toxicity were seen following intraperitoneal injection of Ad-RA538. The adenoviral vector was present in the liver, spleen, kidney and stomach of mice injected with 10(9) pfu Ad-RA538. Six and 12 days after injection, mild inflammation was observed in the liver of mice received 10(9) pfu Ad-RA538. CONCLUSION: Ad-RA538 is safe both in vivo and in vitro, and clinical trials of Ad-RA538 can be performed.

Adenovirus E1 Proteins↗

PubMed1999

[Apoptosis of ovarian carcinoma cell line induced by amiloride].

OBJECTIVE: To investigate induction of apoptosis and its possible mechanism in amiloride-treated ovarian carcinoma cell line. METHODS: Morphological changes of apoptotic cells were investigated by light and fluorescence microscopy. DNA fragmentation was analysed by agarose gel electrophoresis. In addition, the number of hypodiploid cells (apoptotic cells) was quantitatively assessed by flow cytometry and intracellular pH was also analysed. RESULTS: Amiloride-treated ovarian carcinoma cells showed morphological characteristics of apoptosis. A ladder-like pattern of DNA fragmentation was demonstrated on agarose gel electrophoresis. Amiloride at 0.01-5 mumol/L could induce apoptosis in 18.7%-61.6% of ovarian carcinoma cells. The apoptosis-inducing effect of amiloride was dose- and time-dependent. In addition, amiloride induced intracellular acidification in a subpopulation of the treated cells. Furthermore, these isolated acidified cells revealed chromatin condensation as well as DNA degradation with characteristics of apoptosis. There was good correlation between apoptotic cells and acidic cells. CONCLUSION: Amiloride triggers apoptosis of ovarian carcinoma cells; intracellular acidification may be involved in the mechanism of apoptosis.

Amiloride↗

PubMed1999

[Clinical and experimental studies on huodan tablet in treating pediatric viral myocarditis].

OBJECTIVE: To study the effect of Huodan Tablet in treating pediatric viral myocarditis. METHODS: Clinical manifestations and physical signs as well as laboratory examinations have been observed. RESULTS: The markedly effective rate was 68%, the total effective rate was 91.67% in therapeutic group, while in control group, the markedly effective rate was 30.83% and the total effective rate 70.84%. According to Ridit analysis, significant difference was shown between the two groups. r-therapeutic group = 0.5000, r-control group = 0.295 + 2 x 0.025, respectively. CONCLUSION: Huodan Tablet has no toxic and side-effect and can be taken safely and conveniently, it complies with the demands of WHO on new drug for prevention and cure of myocarditis.

Adolescent↗

PubMed1999

[Effect of immunologic treatment on lymphocyte subsets in patients with myasthenia gravis].

OBJECTIVE: To study the abnormalities of cellular immunity of myasthenia gravis (MG) and the effects of glucocorticoid (GC) therapy and thymectomy on lymphocyte subsets in patients with myasthenia gravis. METHODS: Phenotypic analysis of peripheral blood lymphocyte in 39 patients with MG and 18 healthy controls were completed using flow cytometry and immunofluorescence double-staining methods; changes of lymphocyte subsets were studied in 15 of the MG patients after GC therapy and 7 of the MG patients after thymectomy. RESULTS: (1) The percentage of pan-T (CD(+)(5)), pan-B (CD(+)(19)), traditional B cell, CD(+)(4)T cell in patients with MG did not significantly differ from that in healthy controls. An increase in CD(+)(8) cell was observed in MG patients as compared with normal controls. Among the CD(+)(4) T lymphocyte subsets, there was significant decrease of the percentage of CD(+)(4) CD(45)RA(+) (suppressor-inducer) and increase of the percentage of CD(+)(4) CD(45)RA(-) (helper-inducer) subsets in MG patients than controls; the percentage of CD(+)(5) B cell was significantly increased in MG patients as compared with that in healthy controls. (2) After GC therapy, the percentages of pan-T (CD(+)(5)), pan-B (CD(+)(19)), traditional B cell, CD(+)(4) T cell, CD(+)(8) T cell, CD(+)(4) CD(45)RA(-), CD(+)(5) B cell decreased. (3) After thymectomy, the proportions of T, B lymphocyte subsets did not change significantly. CONCLUSION: Not only changes of T cell subsets (CD(+)(4) and CD(+)(8) T lymphocyte subsets) were shown, but also there were abnormal changes of functional CD(+)(4) T lymphocyte subsets and CD(+)(5) B lymphocyte which may play an important role in the pathogenesis of MG. There is comprehensive inhibiting action of GC on cellular immunity in MG patients, while there is no such effect with thymectomy on the lymphocyte subsets in MG patients.

Adolescent↗

PubMed1999

[Flow cytometry for testing chemosensitivity of malignant bone tumors].

OBJECTIVE: To study chemosensitivity and multidrug resistance of malignant bone tumors and to make an individual protocol of chemotherapy with sensitive antitumor agents. METHODS: Apoptosis induced by MTX, ADM, MMC, VP-16, VCR and CTX, and chemosensitivity in 32 fresh specimens of malignant bone tumors were analyzed by flow cytometry (FCM) and quantitative immunofluorescence. The expression of P-glycoprotein (P170) in the specimen and the relation between P170, multidrug resistance, and chemosensitivity were detected. RESULTS: The rate of apoptosis was significantly different in malignant bone tumor cells treated with different drugs: MTX (30.50 +/- 10.22)%, ADM (26.28 +/- 9.35)%, MMC (23.11 +/- 7.38)%, VP-16 (18.17 +/- 6.14)%, VCR (4.44 +/- 2.55)%, and CTX (1.22 +/- 0.59)%. The individual variation of cell apoptosis was prominent in the specimens of same pathological type treated with same agent. There was lower chemosensitivity in the malignant bone tumors with a high expression of P170. CONCLUSIONS: Chemosensitivity testing by flow cytometry is a simple, quick and sensitive assay. Quantitative analysis of expression of P170 could be used to predict multidrug resistance and its chemosensitivity of malignant bone tumors.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1999

[Experimental studies on antioxidative effect of tongcao and xiao-tongcao polysaccharides].

OBJECTIVE: To observe the antioxidative effect of four kinds of Tongcao and Xiao-Tongcao polysaccharides. METHOD: Aged mice (nine months) were abdominal administrated with four kinds of polysaccharides (Tongtuomu, Ximashanjingjiehua, Xinanxiuqiu, Ditanghua) at dosages of 160 mg/kg and 80 mg/kg for 45 days. RESULT: Four kinds of polysaccharides could obviously decrease the content of serum and liver lipoperoxide(LPO) as well as the content of lipofuscin(LF) in brain and cardiac muscle of aged mice, and also increase the activity of superoxide dismutase(SOD) of red cells in aged mice. CONCLUSION: The polysaccharide components of Tongtuomu and three kinds of Xiao-Tongcao have antioxidative effect, suggesting that these substances have antiageing function.

Animals↗

PubMed1999

[Leukocyte adhesion molecule expression and circulating ICAM-1, E-selectin levels during cardiopulmonary bypass in patients undergoing valve replacement].

The objectives of this study were to measure leukocyte adhesion molecule expression, assess the possibility of evaluating the serum levels of the soluble form of endothelium adhesion molecule as an alternative for endothelia cell activation, and analyze the correlation and regression between leukocyte adhesion molecule expression and soluble endothelium adhesion molecule levels during cardiopulmonary bypass (CPB) in patients undergoing valve replacement. Twelve adult patients were included in this study. The extracorporeal circuit was primed with Ringer's lactate. After systemic heparinization (300 IU/kg), CPB was initiated with a bubble oxygenator. Patients were cooled to about 28 degrees C, at that temperature, aorta was clamped and cold crystalloid cardioplegia was delivered into aortic root. The activatal clotting time was maintained at greater than 450 seconds. 1-1. 3 mg of protamine was administered for each 100 IU of heparin given prior to CPB. Peripheral blood was collected at the day prior to surgery and the morning of postoperative days 1, 2, 5, and 7 for determination of the expression of leukocyte CD11a, CD18, CD11a/CD18, CD11b, CD11b/CD18 (immunofluorescent flow cytometry) and the plasma soluble intercellular adhesion molecule-1(sICAM-1), soluble E-selectin (sE-selectin) (enzyme-linked immunoabsorbent assay). CPB caused a sustained increase in the leukocyte CD11a, CD18, CD11a/CD18, CD11b/CD18 expression and the plasma sICAM-1, sE-selectin levels in patients (P < 0.05). Upregulation of the leukocyte adhesion molecule expression and increase of the circulation endothelium adhesion molecule levels lasted at least 2 days after surgery (P < 0.05) except CD11a. There were correlation and regression between leukocyte adhesion molecule expression and soluble endothelium adhesion molecule levels (r = 0.91-0.99, P = 0.0322-0.0005; Y = -1377.06-44.64 + 1.49-14.78a to Y = 44.64 + 1.49a). These results suggest that CPB causes obvious leukocyte-endothelia interactions, that the expression of these adhesion molecules are presented by means of receptor-ligand form, and that the measurement of sICAM-1 and sE-selectin may well be used as a marker of endothelial cell activation.

Adult↗

PubMed1999

[Significance of apoptosis status and apoptosis-associated antigen expression in human colorectal adenocarcinoma sequence].

To investigate the effects of apoptosis on colorectal tumorigenesis and its possible biological significance, the apoptotic frequency in primary cultural cell of 9 normal mucosa, 4 adenomas and 9 adenocarcinomas in time period of 2, 12, 24, 48 hour was measured by flow cytometry. The apoptotic cells index (AI) in situ for 15 colorectal normal mucosa, 7 hyperplastic epithelial, 25 adenomas and 77 adenocarcinomas was identified by the terminal deoxynucleotidyl transferasemediated dUTP-biotin nick end labeling technique (TUNEL). Ki-67 proliferate index (KI), wafl and p53 genes were immunostained with ABC method. The results showed that culture related apoptotic incidence was obviously decreased in cultural tumor cell when compared with mucosa cell after 24-48 hour in vitro. There was a directly positive relationship between the spontaneous apoptosis and Ki-67-index in vivo. The well differentiated or early stage lesions with intensive bcl-2 expression were significantly more likely to have low AI and KI. Both mp53 accumulation and wafl depression which mainly related to KI, had no apparent correlation with AI, bcl-2/bax expression and clinicopathological features statistically; elevatory bax/bcl-2 and pervasive wafl depression led to an increasing AI/KI both in adenoma with atypia and in advanced cancer with distant metastasis or embolus, comparatively. The data indicated that the reduction of susceptibility to inductive apoptosis may contribute to the early phase of tumorigenesis, that AI in vivo may reflect proliferative activity, and that bcl family was closely associated with spontaneous apoptosis and biological behavior of human colorectal cancer.

Adenocarcinoma↗

PubMed1999

[An analysis of DNA content in 405 cases of human tumor by flow cytometry].

This study was intended to evaluate the relationship between the DNA content of cell cycle and the histology in human tumors. We detected the DNA content in 405 cases of fresh human tumor tissue by means of flow cytometry and observed the histology of tumor with light microscopy. The occurrences of aneuploidy in 22 cases of benign tumor and 383 cases of malignant tumor were 27% and 52% respectively. There were differences in aneuploidy in different histologic types of tumor. The aneuploidy in adenocarcinoma was about 50%, that in sarcoma was more than 37%, and that in squamous carcinoma less than 17%. S > or = 10, G2/m > or = 10 or S > or = 20, G2/m > or = 5 were present in malignant tumors, but were not found in benign tumors. The results suggest that there is obvious difference in the occurrences of aneuploidy in benign and malignant tumors and in different histologic type of tumor(P < 0.05). Benign and malignant tumor may be distinguished when SPF and G2/m reach a higher level (P < 0.01).

Carcinoma, Squamous Cell↗

PubMed1999

[Changes of F-actin in neutrophils under fluid shear stress].

Neutrophils are the main defender in the body, and their physiological characters are associated with functions. Because the environments of neutrophils maturation and storage are different from their function environment, they have to adapt thess changes. Filamentous actin (F-actin), as one of the important cytoskeleton components of neutrophils, has different quantity and distribution under different physiological conditions. Previous researches are all focused on static activation of neutrophils using various stimulants such as formyl-methionyl-leucyl-phenylalanine (f-MLP) and tumor necrosis factor(TNF). In our study, Low-Shear 30 and NXE-1 rheometers were used to provide steady or sinusoidaloscillatory fluid shear stress on separated neutrophils. Fluorescent agent Tritc-Phalloidin was added to label F-actin and the mean fluorescent intensity tested by flow cytometry was used as the indication of F-actin quantity and confocal laser scan microscope was used to detect the distribution of F-actin in neutrophils. We found that F-actin polymerization was significantly decreased under both steady and sinusoidal-oscillatory shear stress when the shear stress was below certain level. The density of the cortex F-actin near cell membrane in cells sheared became thinner than in that without shear stress. f-MLP and TNF both could increase actin polymerization in neutophils due to activation. When neutorphils were activated with f-MLP or TNF under shear stress, the quantity of F-actin in the cells was also decreased, but it was still higher than that in the cells absent of f-MLP or TNF. We concluded that neutrophils had different mechanical properties in different fluid environments. F-actin content and distribution would change according to the shear stress values to play their determinant role in neutrophils mechanical adaptation. The mechanism of actin polymerization in neutrophils for mechanical action is probably different from that for chemoattractants and cytokine activation.

Actins↗

PubMed1999

[Effects of fluid shear stress on neutrophil surface expression of adhesion molecules].

Fluid shear is a physiological and functional environment for circulating neutrophils where various chemoattractants and cytokines have different effects on neutrophils, activating them or evoking inflammation. So far there have been abundant in vitro researches demonstrating that while neutrophils are activated, some adhesion molecules, which are expressed on the surface of neutrophils, are necessary to cell-to-cell adhesion, and the quantity or quality of these molecules will be changed. The above results were all obtained under static fluid which is quite different from physiological condition. Recently, we used Low-Shear 30 to provide steady or sinusoidal-oscillated fluid shear stress on separated neutrophils with or without f-MLP/TNF stimulation. FITC-anti CD18 monoclonal antibody and PE-anti CD62L monoclonal antibody were added to label CD18 and CD62L on neutrophils suface respectively. Flow cytometry was used to quantify surface expression and positive cell percentage of these two adhesion molecules. The results demonstrat that fluid shear stress increases the expression of CD18 significantly and decreases the CD62L positive cell percentage, but it does not influence the CD62L expression on the CD62L positive cells. The effects of the different patterns of fluid shear stress are not much different, f-MLP or TNF can slightly decrease the expression of CD18 and make CD62L shedding respectively. When one of the two activators and the fluid shear stress act together, the expression of the two adherent molecules can be added. This indicates that the mechanical and biochemical stiumlative action can produce different effects through different receptors and different signal transduction pathways. So the mechanical environment should be considered in the research of activation and adhesion of neutrophils.

Adult↗

PubMed1999

[The measurement of QT dispersion using wavelet transformation].

This paper addressed the application of wavelet to the measurement of QT dispersion and presented a new method using multi-thresholds to determinate the end point of T-wave. The results geined by computer and human were compared. We also suggested that QT dispersion be defined as the SD of 12 QT intervals.

Algorithms↗