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Biomedical subjects

Yang Xiang

Publications and source records attributed to Yang Xiang.

70 records · Page 4Linked to original sources
PubMed2003

[In vivo reversal of multidrug resistance by transduction of human tumor necrosis factor-alpha into drug resistant cell line of choriocarcinoma].

OBJECTIVE: To investigate in vivo reversal of multidrug resistance and biological properties of a drug resistant cell line of choriocarcinoma transduced by human tumor necrosis factor-alpha (TNF-alpha) gene via the establishment of its animal model. METHODS: Choriocarcinoma cell line JEG-3, drug-resistant choriocarcinoma cell line JEG-3/VP2, and human TNF-alpha-transduced drug-resistant choriocarcinoma cell line JEG-3/VP2/TNF-alpha were injected subcutaneously in the neck of nude mices. Tumor size and weight were routinely measured, tumor histological structure was observed and its chemosensitivity was tested. Expression of multidrug resistance (MDR1) mRNA was investigated using reverse transcription-polymerase chain reaction (RT-PCR) and P-glycoprotein (P-gp) expression was determined by immunohistochemistry with the monoclonal antibody MDR1. RESULTS: The rate of inoculation for all three tested cell lines was 100%, the latent period was 10 to 14 days. Tumor growth rates and weights were significantly different among three cell lines (P < 0.05), with the lowest in JEG-3/VP2/TNF-alpha cell line. Tumor inhibition rate after treatment with etopside (VP-16) was significantly higher in JEG-3/VP2/TNF-alpha (41.0% - 42.5%) (P < 0.05), compared with JEG-3/VP2 (24.3% - 28%), and similar to JEG-3 (46.7% -47.7%). Transduction and expression of human TNF-alpha in drug-resistant choriocarcinoma cell line JEG-3/VP2 was found to reverse MDR1 on the mRNA and P-gp levels. CONCLUSION: Transduction and expression of human TNF-alpha in drug-resistant choriocarcinoma cell line JEG-3/VP2 can reverse expressions of MDR1 mRNA and P-gp, enhance the susceptibility of the JEG-3/VP2 to the cytotoxic drugs, and lower its tumorigenesis.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

[Floxuridine-containing regime in the treatment of gestational trophoblastic tumor].

OBJECTIVE: To analyse the efficacy of the floxuridine (FUDR)-containing regime (single agent or in combination) in the treatment of gestational trophoblastic tumor. METHODS: Seventy-four patients with gestational trophoblastic tumors (GTT), 47 invasive mole and 27 choriocarcinoma, were treated with FUDR-containing regime. The clinical staging of the disease were: 33 cases of stage I, 3 cases of stage II, 31 cases of stage IIIa, 6 cases of stage IIIb, and 1 case of stage IV. RESULTS: The cure rate of FUDR-containing regime in the treatment of GTT was 91.9% (68 out of 74 cases). Twenty-one out of these 74 patients showed drug resistant to 5-FU-containing or MTX-containing regime and were cured after they changed to the FUDR-containing regime. All 7 patients of advanced stage (> or = III b) got cured. The major adverse event of FUDR-containing regime was myelodepression and gastrointestinal toxicity: III-IV degree granulopenia 26%, III-IV thrombopenia 6.2%, III degree vomiting 57.1%, and III degree diarrhea 4.3%. CONCLUSION: FUDR-containing regime is efficient for the treatment of GTT, even for those with advanced stage or drug-resistant disease.

Adolescent↗
PubMed2003

[Evaluation of surgical resection of pulmonary metastasis of trophoblastic tumour].

OBJECTIVE: To evaluate the role of lung lobectomy in the patients of tumor with lung metastases. METHODS: A total of 45 cases of trophoblastic tumor with pulmonary metastases treated by lung lobectomy from 1985-2002 at PUMC hospital was retrospectively analyzed. Seven cases were diagnosed as invasive mole and thirty-eight as choriocarcinoma. RESULTS: Lung lobectomy was performed in all of these patients after several courses of chemotherapy. Seven cases of invasive mole reached complete remission. Eleven cases of choriocarcinoma with stage IIIa had received average 13 courses of chemotherapy, 10 of them reached complete remission. Seventeen cases of choriocarcinoma with stage IIIb had received average 14.3 courses of chemotherapy, 11 of them reached complete remission. Ten cases of choriocarcinoma with stage IV had received average 15 courses of chemotherapy, six of them reached complete remission. In the 45 patients, histologic examination disclosed haemorrhagic necrotic tissue in 27 patients, 17 of them reached complete remission (63%). Histologic examination also revealed fibrosis around the focus in 16 patients, 14 of them reached complete remission (88%). Tuberculosis was found in 2 patients. CONCLUSIONS: Although the development of effective chemotherapy has resulted in improved survival of patients with gestational trophoblastic tumor, lung lobectomy remains an important adjunct treatment in a selected subset of patients. Pathological examinations can help to estimate the prognosis.

Adolescent↗
PubMed2003

[Fertility preservation in the management of gynecologic cancers].

Cancer treatment has improved the rate of survival associated with neoplasias, and cancer survivors are more and more interested in preserving fertility potential. This article focuses on new and innovative techniques as well as approaches to treat gynecologic cancers while minimizing the negative fertility effects of cancer treatment. In particular, the radical trachelectomy procedure in cervical cancer, hormonal treatment of early endometrial cancer, conservative surgical management of early-stage epithelial ovarian cancer, and novel assisted reproductive technologies for women with impaired ovarian function after cancer treatment are discussed.

Adult↗
PubMed2003

[Quantitative analysis of resveratrol from grape seeds and grape skins by high performance liquid chromatography method].

In order to perform a quantitative analysis of resveratrol from grape seeds, grape skins and waste residue of grape winery, acetonitrile-water (26:74) was applied as the fluxion phase. The detective wave-length (lambda) was 303 nm. Colume temperature was 35 degrees C. The type of chrimato pattern colume was SupelcosiLTMLC-18 (250 mm x 4.6 mm, 5 microns). Results showed that the contents of resveratrol from grape skins were higher than those of grape seeds. Among different kinds of grape skins, resveratrol contents varied. The reserveratrol content of Suo Suo grape skin was the lowest (0.9850 microgram/g). Among the same kinds of grape skins from the same production area, the resveratrol content was highest in the skin of waste residue of grape winery followed by the fresh grape skin and the old grape skin ranked thirdly, and the differences of resveratrol contents were statistically significant.

Chromatography, High Pressure Liquid↗
PubMed2003

[Significance of serum/cerebrospinal fluid human chorionic gonadotropin ratio and prophylactic intrathecal therapy in patients with brain metastases of gestational trophoblast tumor].

OBJECTIVE: To evaluate the effect of serum/cerebrospinal fluid (CSF) ratio of human chorionic gonadotropin (hCG) in detecting brain metastases of gestational trophoblast tumor and the significance of prophylactic intrathecal therapy. METHODS: Clinical information of 44 patients with brain metastases (stage IV) and 29 patients with lung metastases (stage III) of gestational trophoblast tumor who were admitted to our hospital between 1986 to 2001 were retrospectively analyzed by case control study. The variability of the ratio and the relationship between brain metastases was investigated, together with the effect of prophylactic intrathecal therapy. RESULTS: Serum/CSF hCG ratio in patients with brain metastases declined with time. The ratio before chemotherapy was in relevant with the size of the lesion which were less than 60 in advanced stages and more than 60 in early stages. Patients of stage III with prophylactic intrathecal therapy did not progress to stage IV. CONCLUSIONS: Serum/CSF hCG ratio before chemotherapy could reflect the encephalic tumor load which had reference value in diagnosis and prognosis and prophylactic intrathecal therapy played an important role in preventing brain metastasis.

Antimetabolites, Antineoplastic↗
PubMed2003

[Prenatal diagnosis and clinical management of a twin pregnancy consisting of a complete mole and coexisting fetus].

OBJECTIVE: To discuss the differential diagnosis of the hydatidiform mole and a coexisting fetus, to study the prenatal diagnosis and the clinical management of a twin pregnancy consisting of a complete mole and coexisting fetus (CMCF). METHODS: Two cases of CMCF were reported retrospectively. RESULTS: In the first case, the hydatidiform mole and a coexisting fetus was found by B mode ultrasound at the 10th gestational week, the patient asked to terminate the pregnancy. The interphase FISH and karyotype analysis of the normal villi and the mole showed both of them were diploid, thus the CMCF was diagnosed. In the second case, the hydatidiform mole and a coexisting fetus was found by B mode ultrasound at the 21st gestational week. Transabdominal chorionic villi sampling and amniocentesis was performed, interphase FISH and karyotype analysis of the mole and the amniotic fluid showed both of them were diploid, thus the CMCF was diagnosed prenatally. The pregnancy was continued and premature rupture of membrane happened at the 28th gestational week, the cesarean section was performed. The neonate was healthy. The karyotype analysis of the placenta and the neonate was accordant with the prenatal diagnosis. CONCLUSIONS: As long as the hydatidiform mole and a coexisting fetus was found the prenatal diagnosis must be performed in order to differentiate the CMCF and the partial hydatidiform mole (PHM). The transabdominal chorionic villi sampling and the amniocentesis were ideal methods, interphase FISH and karyotype analysis of the mole and the amniotic fluid should be performed. If both of them were diploid, the CMCF could be diagnosed. The clinical management of CMCF should be done individually. If both of them were triploid, the PHM could be diagnosed.

Adult↗
PubMed2002

Caveolar localization dictates physiologic signaling of beta 2-adrenoceptors in neonatal cardiac myocytes.

There is a growing body of evidence that G protein-coupled receptors function in the context of plasma membrane signaling compartments. These compartments may facilitate interaction between receptors and specific downstream signaling components while restricting access to other signaling molecules. We recently reported that beta(1)- and beta(2)-adrenergic receptors (AR) regulate the intrinsic contraction rate in neonatal mouse myocytes through distinct signaling pathways. By studying neonatal myocytes isolated from beta(1)AR and beta(2)AR knockout mice, we found that stimulation of the beta(1)AR leads to a protein kinase A-dependent increase in the contraction rate. In contrast, stimulation of the beta(2)AR has a biphasic effect on the contraction rate. The biphasic effect includes an initial protein kinase A-independent increase in the contraction rate followed by a sustained decrease in the contraction rate that can be blocked by pertussis toxin. Here we present evidence that caveolar localization is required for physiologic signaling by the beta(2)AR but not the beta(1)AR in neonatal cardiac myocytes. Evidence for beta(2)AR localization to caveolae includes co-localization by confocal imaging, co-immunoprecipitation of the beta(2)AR and caveolin 3, and co-migration of the beta(2)AR with a caveolin-3-enriched membrane fraction. The beta(2)AR-stimulated increase in the myocyte contraction rate is increased by approximately 2-fold and markedly prolonged by filipin, an agent that disrupts lipid rafts such as caveolae and significantly reduces co-immunoprecipitation of beta(2)AR and caveolin 3 and co-migration of beta(2)AR and caveolin-3 enriched membranes. In contrast, filipin has no effect on beta(1)AR signaling. These observations suggest that beta(2)ARs are normally restricted to caveolae in myocyte membranes and that this localization is essential for physiologic signaling of this receptor subtype.

Animals↗
PubMed2002

The PDZ binding motif of the beta 1 adrenergic receptor modulates receptor trafficking and signaling in cardiac myocytes.

Beta(1) and beta(2) adrenergic receptors (AR) regulate the intrinsic contraction rate in neonatal mouse cardiac myocytes through distinct signaling pathways. It has been shown that stimulation of beta(1)ARs leads to a protein kinase A-dependent increase in contraction rate. In contrast, stimulation of beta(2)ARs has a biphasic effect on contraction rate, with an initial protein kinase A-independent increase followed by a sustained decrease that is blocked by pertussis toxin. The beta(2)AR undergoes agonist-induced endocytosis in cardiac myocytes while the beta(1)AR remains on the cell surface. It has been shown that a PDZ domain binding motif at the carboxyl terminus of beta(1)AR interacts with the postsynaptic density protein PSD-95 when both are expressed in HEK293 cells. We found that mutation of this PDZ binding motif in the beta(1)AR (beta(1)AR-PDZ) enabled agonist-induced internalization in cardiac myocytes. Moreover, stimulation of beta(1)AR-PDZ had a biphasic effect on the myocyte contraction rate similar to that observed following stimulation of the beta(2)AR. The secondary decrease in the contraction rate was mediated by G(i) and could be blocked by pertussis toxin. Furthermore, a non-selective endocytosis inhibitor, concanavalin A, inhibited the internalization of wild type beta(2)AR and the mutated beta(1)AR-PDZ, and blocked the coupling of both receptors to G(i). Finally, treating myocytes with a membrane-permeable peptide representing beta(1)AR PDZ motif caused the endogenous beta(1)AR to behave like beta(1)AR-PDZ. These studies suggest that association of the beta(1)AR with PSD-95 or a related protein dictates signaling specificity by retaining the receptor at the cell surface and preventing interaction with G(i).

Adaptor Proteins, Signal Transducing↗
PubMed2002

Focus retrocollimated interferometry for focal-length measurements.

Focus retrocollimated interferometry is developed for the measurement of focal lengths of optical lenses and systems, and achievable accuracy is discussed. It is shown that this method can be used to measure both short and long focal lengths simply and with high accuracy.

Journal Article↗
PubMed2002

[Transfection of MDR1-mRNA into human mononuclear cells to improve their resistance to anticancer agents, an in vitro study].

OBJECTIVE: To investigate the expression and function of P-glycoprotein (P-gp), an efflux pump encoded by multidrug resistance complementary DNA (MDR1), in human mononuclear cells (MNCs) transfected with MDR1 mRNA. METHOD: Two kinds of human MDR1 mRNA, pT7TS-MDR1 and pGEM5Zf (+)-MDR1 with difference in the 5' and 3' untranslated regions only, were constructed and modified and then were transfected into human MNCs rich in hematopoietic progenitor cells from a patient with small cell lung cancer. The expression efficiency and pump function of P-gp were measured with FACS. Rhodomine 123 efflux test was used to examine the function of P-gp. Un- transfected mononuclear cells from the same person were used as controls. RESULT: The expression of P-gp 12 hours after transfection was 2.16 % in control group, 8.94% in pGEM5Zf (+)-MDR1 group, and 19.14% in pT7TS-MDR1 group. The expression of P-gp 72 hours after transfection was 2.12% in control group, 6.12% in pGEM5Zf(+)-MDR1 group, and 10.71% in pT7TS-MDR1 group, significantly higher in the third group. Rhodamine-123 efflux test showed that the efflux-pump function of P-gp 12 hours after the trransfection was 19.20% in control group, 25.59% in GEM5Zf (+)- MDR1 group, and 35.02% in pT7TS-MDR1 group (all P < 0.01). The expression and presence of P-gp by transfected cells lasted at least 72 hours. CONCLUSION: Transfection of human mononuclear cells with MDR1 mRNA significantly increases their resistance to anticancer agents.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

[Influence of regulatory peptides on the secretion of interleukins from bronchial epithelial cells of the rabbit].

To explore the role of regulatory peptides in the secretion of bronchial epithelial cells (BECs), we observed the effects of four peptides, i.e.vasoactive intestinal peptide (VIP), epidermal growth factor (EGF), endothelin-1 (ET-1), and calcitonin gene-related peptide (CGRP), on the secretion of ILs from unstimulated or O3-stressed BECs. The results of the experiments showed that VIP exerted an inhibitory effect on the secretion of IL-1 and IL-8 from unstimulated and O3-stressed BECs, VIP also decreased the secretion of IL-5 from O3-stressed BECs; EGF promoted secretion of IL-1 and IL-8 from unstimulated BECs, but decreased the secretion of ILs from O3-stressed BECs; ET-1 and CGRP enhanced the secretion of IL-1, IL-5, and IL-8 from unstimlated BECs, CGRP also increased the secretion of ILs from O3-stressed BECs. The results obtained demonstrate that intrapulmonary regulatory peptides modulate the secretion of ILs from BECs, and may play an important part in transduction of inflammatory signals.

Animals↗
PubMed2002

Nerve growth cone guidance mediated by G protein-coupled receptors.

Growing axons navigate by responding to chemical guidance cues. Here we report that growth cones of rat cerebellar axons in culture turned away from a gradient of SDF-1, a chemokine that attracts migrating leukocytes and cerebellar granule cells via a G protein-coupled receptor (GPCR). Similarly, Xenopus spinal growth cones turned away from a gradient of baclofen, an agonist of the GABA(B) receptor. This response was mediated by G(i) and subsequent activation of phospholipase C (PLC), which triggered two pathways: protein kinase C (PKC) led to repulsion, and inositol 1,4,5-triphosphate (IP(3)) receptor activation led to attractive turning. Under normal culture conditions, PKC-dependent repulsion dominated, but the repulsion could be converted to attraction by inhibiting PKC or by elevating cytosolic cGMP. Thus, GPCRs can mediate both repulsive and attractive axon guidance in vitro, and chemokines may serve as guidance cues for axon pathfinding.

Aminocaproic Acid↗
PubMed2002

[Superselective arterial embolization for hemorrhage from malignant gestational trophoblastic tumor].

OBJECTIVE: To evaluate the efficacy of superselective arterial embolization to control hemorrhage from malignant gestational trophoblastic tumor. METHODS: From February 1990 to June 2001, 31 patients (choriocarcinoma 24, invasive mole 7) with hemorrhage from malignant gestational trophoblastic tumor were treated with superselective arterial embolization. The hemorrhage organs included uterus (22 cases), vagina (3 cases), liver (3 cases), bladder (2 cases), and intestine (1 case). RESULTS: In 28 cases (90.3%), superselective arterial embolization successfully controlled the hemorrhage. Hysterectomy was performed in the 3 failed and uterine perforation was revealed by laprotomy. Four patients had normal term delivery after successful superselective arterial embolization and chemotherapy. CONCLUSION: Superselective arterial embolization can effectively control the hemorrhage from malignant gestational trophoblastic tumor.

Antineoplastic Agents↗
PubMed2002

Acetazolamide suppresses tumor metastasis and related protein expression in mice bearing Lewis lung carcinoma.

AIM: To study the suppressing effect of acetazolamide on tumor metastasis in vivo and observe the protein alteration of lung in mice bearing Lewis lung carcinoma. METHODS: The functional role of aquaporin-1 (AQP1) was investigated in tumor tissues by SDS-PAGE and Western blot. The effect of acetazolamide on tumor metastasis was analyzed by Lewis-lung-carcinoma model. Differential protein was identified by SDS-PAGE, isoelectrofocusing (IEF) methods, and peptide mass fingerprinting (PMF). RESULTS: Acetazolamide (40 mg/kg/d po for 21 d) dramatically reduced the numbers of lung metastasis after sc inoculating Lewis lung carcinoma. The inhibition rate of lung metastases was 83.9 %. Simultaneously, the AQP1 protein level and actin-cytoplasmic in lungs containing metastatic tumor deposits were found to be higher than that in the normal tissue. After treated with acetazolamide for 21 d, the expression of AQP1 was obviously inhibited. CONCLUSION: Acetazolamide can suppress tumor metastasis, at least in part, by inhibiting the expression of AQP1. AQP1 and actin-cytoplasmic may be new prognostic molecules as well as new therapeutic targets for the prevention and treatment of metastatic tumor.

Acetazolamide↗