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Biomedical subjects

Y Wu

Publications and source records attributed to Y Wu.

At least 289 records · Page 16Linked to original sources
PubMed2001

[Study of Chinese herbal medicine in treating ascites and their mechanism in regulating lymphatic stomata].

OBJECTIVE: To study the therapeutic effect of Chinese herbal medicines (CHM) in treating ascites to elucidate its mechanism in regulating the lymphatic stomata and promoting the absorption of ascites from the peritoneal cavity. METHODS: Using scanning electron microscope (SEM) and computerized image processing and quantitative analysis assays, the CHM extract consisting of Atractylodes macrocephala, Salvia miltiorrhiza, Codonopsis pilosula, Alismatis orientale and Leonurus heterophyllus were studied. RESULTS: Intraperitoneal injection of nitric oxide (NO) supplier or CHM administration could cause the average area of lymphatic stomata obviously enlarged (P < 0.05), and the open numbers significantly increased (P < 0.01) in normal healthy mice. When L-notroarginine, a NO synthetase suppressor, was injected after CHM administration, it was found that the regulating effect of CHM on lymphatic stomata was inverted obviously, i.e. the average area and the density of lymphatic stomata were markedly reduced (P < 0.01). CONCLUSION: CHM might treat ascites through increasing the endogenous NO concentration to open the lymphatic stomata and in turn to conduct the peritoneal water through lymphatic path.

Animals↗
PubMed2001

[Study on antitumor effect and mechanism of aloe polysaccharides].

OBJECTIVE: To study the antitumor activity and mechanism of aloe polysaccharides (AP). METHODS: AP was administered i.p. or i.v. to Sarcoma 180(S180) bearing mice or Hepatoma22(H22) bearing mice solely or combining with CTX, FU and ADM respectively. 10 days later, for S180 mice, the blood was analyzed, the tumor was peeled off and weighed, and the spleen index, thymus index was calculated. For H22 bearing mice, the survival rate was observed or the IL-2, TNF content in serum was tested. RESULTS: 25 mg/kg.d or 50 mg/kg.d AP group could evidently reduce the tumor weight of S180 bearing mice and prolong the survival time of H22 bearing mice. AP also could improve the antitumor effects of CTX, ADM, FU, and lessen the chemotherapy side-effects. Furthermore, AP could improve the level of IL-2, TNF in the serum of mice bearing S180 or H22. CONCLUSION: AP has the effects of antitumor, enhancing the antitumor activity of chemotherapy drugs and lessening their side-effects. This effect was possibly derived from inducing IL-2 and TNF producing in body and improving the immunity activity.

Aloe↗
PubMed2001

[The stereocontrolled synthesis of 1-acetylenyl-3-tert-butyldiphenylsilyloxy-exo-bicyclo [3. 1. 0] hexane].

OBJECTIVE: In order to find out more effective method for the synthesis of the A-ring synthon, (-)-1-acetylenyl-3-tert-butyldiphenylsily-loxy-exo-bicyclo [3. 1. 0] hexane (3), for 19-nor-1 alpha, 25-dihydroxyvitamin D3(2)with commercial value. METHODS: We synthesized the A-ring synthon (+/-)(3) via nine steps with good yield starting from 3-cyclopentenyl alcohol(4). RESULTS: The spectral data of compound (+/-)(3) is the same as the spectral data of (-)(3) which reported preciously by us. CONCLUSION: The method is an effective method for synthesis of the A-ring synthon (3).

Alkynes↗
PubMed2001

[Effect of human umbilical vein endothelial cells on granulopoiesis, erythropoiesis and megakaryopoiesis in mice].

OBJECTIVE: To investigate the effects of endothelial cells on the proliferations of granulocytic, erythrocytic and megakaryocytic progenitor cells. METHODS: Human umbilical vein endothelial cells were collected within 12 hours after cesarean section and were cultured according to Jaffe's method. The human endothelial culture supernatant (HECS) harvested from primary culture medium was centrifuged. Bone marrow mononuclear cells of mice were prepared and then cultured in semi-solid agar or methylcellulose with the addition of HECS. RESULTS: Colony-forming yields were increased in the culture systems with HECS. But in the systems with no HECS, exogenous GM-CSF, EPO and IL-3 added to the hematopoietic progenitor cultures were necessary to induce colony-forming. Synergistic increase in progenitor cell expansion was observed when both HECS and exogenous cytokines were added to hematopoietic progenitor cultures. CONCLUSION: 1. Endothelial cells can support the proliferation and differentiation of hematopoietic stem and progenitor cells. 2. HECS as a source of standard hematopoietic growth factors can be used in the expansion of stem cells in vitro and in the therapy of hemopathy. 3. Interactions between endothelial cells and hematopoietic stem cell or progenitors may play an important role in the regulation of hematopoiesis in vivo. 4. Endothelial cells may produce other soluble growth factors potentiating the action of a set of cytokines such as GM-CSF and IL-6.

Animals↗
PubMed2001

[Analysis on the sex ratios at birth for deliveries in hospitals in China from 1987 to 1992].

OBJECTIVE: To estimate the sex ratios at birth (SRB) for livebirths in hospitals in China. METHODS: Data were collected by the birth defects monitoring network. The livebirths with gestation of 28 weeks or over delivered in hospitals of 30 provinces, municipalities and autonomous regions all over the country from 1987 to 1992 were analyzed and used for calculating the SRB. RESULTS: The high male bias in SRB was observed in the data from most areas, and there was an upward trend of SRB, especially in rural areas. The SRB for livebirths in the hospitals of urban areas was normal from 1987 to 1989, and rose to 108.9 in 1992. The SRB for rural areas was high and was 109.9 in 1987, and rose to 111.8 in 1992. The SRB for livebirths given by the mothers under 20 years of age and coming from lower educational background was higher than that for others. The SRB for higher parities was even higher. CONCLUSION: The SRB in China is high; this is possibly related to sex-preference. Under-reporting of female neonates and "missing females" are not the main causes of the rising SRB.

China↗
PubMed2001

[A multi-centered clinical study an domestic intravenous Turbutalin sulfate in the treatment of asthma and chronic asthmatic bronchitis].

OBJECTIVE: This multi-centered clinical trial was designed to assess the efficacy and safety of domestic intravenous Turbutalin Sulfate in the treatment of asthma and chronic asthmatic bronchitis. METHODS: Bricanyl was used as control. A total of 120 patients were included in this randomized controlled study. The two medications, both at a dose of 0.25 mg intravenous drip, were given three times a day for 3-5 days. RESULTS: The two drugs' clinical excellent rates were 66.7% and 73.3%; overall efficacy rates were 98.3% and 100.0%, respectively. Their pulmonary functional excellent rates were 78.4% and 76.6%; overall effect rates were 88.3% and 90.0%, respectively. Composite curative evaluation showed that the two drug's composite excellent rates were 61.6% both; their overall efficacy rates were 88.3% and 90.0%, respectively. All of these showed no significant difference (P > 0.05). The incidence rates of adverse side effects of the two groups were 13.5% and 15.0%, respectively; most of them were mild and tolerable. CONCLUSION: Domestic intravenous Terbutalin Sulfate is effective and safe in treating asthma and chronic asthmatic bronchitis.

Adolescent↗
PubMed2001

[Inflammatory mediator in patients with obstructive jaundice and its effect on renal function].

OBJECTIVE: To investigate the effect of inflammatory transmitter on renal function in obstructive jaundice. METHODS: 15 patients with obstructive jaundice (OJ) as the experimental group and 15 non-joundiced patients as the control group were involved in this study. The plasma ET, LPS, TNF-alpha, IL-6, IL-8 and urine REP, TFR, ALB were measured in 15 patients with OJ before and 1, 4, 7 days after surgery and in 15 patients without jaundice as controls. RESULTS: The levels of plasma ET, LPS, TNF-alpha, IL-6, IL-8 and urine RBP, TFR, ALB increased significantly at multiple time points as compared with those in the non-OJ patients (P < 0.05), and the changes of plasma ET, LPS, TNF-alpha, IL-6, IL-8 are the same as those of urine RBP, TFR, ALB. CONCLUSION: These data suggest that there is interaction between ET, LPS, TNF-alpha, IL-6, IL-8 and the damage to renal function with OJ after surgery.

Adult↗
PubMed2001

[Correction for the spectral interferences of rare-earth matrix to the determination of calcium by spectral fitting matrix projection-Kalman filter method].

The spectral interferences of trace elements from high purity rare earth will seriously affect the analytical accuracy in the ICP-AES analysis. In this work, spectral fitting matrix projection-Kalman filter method was developed and applied to correction of spectral interferences produced by rare earth matrix peaks with simple shapes in determination of calcium, and it was applied to correct spectral interferences caused by terbium oxide and dysprosium oxide respectively, and satisfactory results were obtained.

Calcium↗
PubMed2001

The Malaria Research and Reference Reagent Resource (MR4) Center--creating African opportunities.

The Malaria Research and Reference Reagent Resource Center (MR4) is a program to support the international malaria research community. The primary goal is to improve access to well-characterized quality-controlled parasite, host and vector reagents for standardization of assays and other general research purposes. MR4 is open to all scientists worldwide, however many of its inaugural activities will have a focus in Africa, where the concept for the MR4 was born. Reagents are donated to the MR4 Center by malaria researchers and their institutions for distribution to other investigators special arrangements are also possible for developing reagents in-house, or for coordinating reagents for multi-site studies. In addition to providing reagents, the MR4 also aims to promotoe technology transfer and to foster scientific exchange between new and established malaria researchers. This will be done via workshops, training programs, and dissemination of information (electronic and hard copy). Suggestions for reagents, information resources, or training opportunities are welcome from the research community to make this a responsive, service-oriented program.

Africa↗
PubMed2001

[Diagnosis and treatment of congenital biliary duct cyst: twenty-year experience].

OBJECTIVE: To summarize the experience in diagnosis and treatment of congenital biliary duct cyst. METHODS: Clinical data from 108 patients treated from 1980 to 2000 were analyzed retrospectively. RESULTS: Abdominal pain, jaundice and abdominal mass were presented in most pediatric patients. Clinical symptoms in adult patients were non-specific, resulting in delayed diagnosis frequently. Fifty-seven patients (52.7%) had coexistent pancreatic biliary disease. Carcinoma of the biliary duct occurred in 18 patients (16.6%). Ultrasonic examination was performed in 94 patients, ERCP in 46, and CT in 71. All of the patients were correctly diagnosed before operation. Abnormal pancreatobiliary duct junction was found in 39 patients. Before 1985, the diagnosis and classification of congenital biliary duct cyst were established by ultrasonography preoperatively and confirmed during operation. The main procedure was internal drainage by cyst-enterostomy. After 1985, the diagnosis was decided with ERCP and CT, the procedure was cyst excision with Roux-en-Y hepaticojejunostomy. In 1994, we used a new and simplified operative procedure to reduce the risk of malignancy of choledochal cyst. Retrograde infection of the biliary tract the major postoperative complication, could be controlled by the administration of antibiotics. CONCLUSIONS: The concept in diagnosis and treatment of congenital choledochal cyst has been changed greatly. CT and ERCP are of great help in the classification of the disease. Currently, cyst excision with Roux-en-Y hepaticojejunostomy is strongly recommended as the treatment of choice for patients with type I and IV cysts. Piggyback orthotopic liver transplantation is indicated for type V cysts (Caroli's disease) with frequently recurrent cholangitis, resulting in biliary cirrhosis.

Adolescent↗
PubMed2000

Synthesis and initial structure--activity relationships of modified salicylihalamides.

[reaction:see text] The first stereoselective total synthesis of the potent antitumor compound (-)-salicylihalamide A is presented. The practicality of our approach provides for high material throughput and is highlighted by the rapid construction of a variety of modified congeners. Initial structure-activity relationships are derived from growth inhibition experiments with a human melanoma cancer cell line.

Amides↗
PubMed2000

Determinants for calmodulin binding on voltage-dependent Ca2+ channels.

Calmodulin, bound to the alpha(1) subunit of the cardiac L-type calcium channel, is required for calcium-dependent inactivation of this channel. Several laboratories have suggested that the site of interaction of calmodulin with the channel is an IQ-like motif in the carboxyl-terminal region of the alpha(1) subunit. Mutations in this IQ motif are linked to L-type Ca(2+) current (I(Ca)) facilitation and inactivation. IQ peptides from L, P/Q, N, and R channels all bind Ca(2+)calmodulin but not Ca(2+)-free calmodulin. Another peptide representing a carboxyl-terminal sequence found only in L-type channels (designated the CB domain) binds Ca(2+)calmodulin and enhances Ca(2+)-dependent I(Ca) facilitation in cardiac myocytes, suggesting the CB domain is functionally important. Calmodulin blocks the binding of an antibody specific for the CB sequence to the skeletal muscle L-type Ca(2+) channel, suggesting that this is a calmodulin binding site on the intact protein. The binding of the IQ and CB peptides to calmodulin appears to be competitive, signifying that the two sequences represent either independent or alternative binding sites for calmodulin rather than both sequences contributing to a single binding site.

Amino Acid Sequence↗
PubMed2000

Thyroid hormone response element sequence and the recruitment of retinoid X receptors for thyroid hormone responsiveness.

Thyroid hormone receptors (TRs) are transcription factors that bind to thyroid hormone response elements (TREs) in the regulatory regions of target genes. TRs are thought to activate transcription primarily as heterodimers with retinoid X receptors (RXRs), with RXR binding upstream to the two directly repeated half-sites in a typical TRE. However, given that TRs and RXRs prefer to bind to different DNA sequences (T(A/G)AGGTCA and GGGGTCA), we postulate that only certain TREs require RXR-TR heterodimerization, depending on the TRE sequence. We have tested this hypothesis by comparing in Saccharomyces cerevisiae the functional activity of TR +/- RXR on 10 naturally occurring mammalian TREs. S. cerevisiae was used as a model system because yeast lack endogenous nuclear receptors and thus can be manipulated to express TRs and/or RXRs. We first studied ligand-independent reporter gene activation, which reflects the activity of the activator function 1 (AF-1) domain. The 10 TREs formed a continuous spectrum from being fully dependent on RXR for TR AF-1 activity to being essentially independent of RXR. Relative independence of RXR generally was seen when the TRE upstream half-site has a TA or TG 5' to the core hexamer. Gel mobility shift assays revealed that functional independence of RXR correlates with the strong binding of TR alone, whereas more RXR dependence correlates with higher binding of RXR-TR heterodimers. Restoration of ligand-dependent (AF-2 domain) reporter gene activation was achieved by expression of the coactivator TIF2. This ligand-induced stimulation was stronger in the presence of TR alone than with RXR plus TR, suggesting a preference for TIF2 activation of TR homodimers. Overall the data support the notion that the TRE sequence plays an important role in determining the nuclear hormone receptor and coactivator requirements for TR action.

Base Sequence↗
PubMed2000

Tumor necrosis factor (TNF) receptor superfamily member TACI is a high affinity receptor for TNF family members APRIL and BLyS.

An expression cloning approach was employed to identify the receptor for B-lymphocyte stimulator (BLyS) and identified the tumor necrosis factor receptor superfamily member TACI as a BLyS-binding protein. Expression of TACI in HEK293T cells confers on the cells the ability to bind BLyS with subnanomolar affinity. Furthermore, a TACI-Fc fusion protein recognizes both the cleaved, soluble form of BLyS as well as the membrane BLyS present on the cell surface of a recombinant cell line. TACI mRNA is found predominantly in B-cells and correlates with BLyS binding in a panel of B-cell lines. We also demonstrate that TACI interacts with nanomolar affinity with the BLyS-related tumor necrosis factor homologue APRIL for which no clear in vivo role has been described. BLyS and APRIL are capable of signaling through TACI to mediate NF-kappaB responses in HEK293 cells. We conclude that TACI is a receptor for BLyS and APRIL and discuss the implications for B-cell biology.

B-Cell Activation Factor Receptor↗
PubMed2000

Defining the requirements for peptide recognition in gene therapy-induced T cell tolerance.

Expression of a retrovirally transduced MHC class I Ag, H-2K(b) (K(b)), in bone marrow-derived cells leads to specific prolongation of K(b) disparate skin grafts. To examine the extent to which peptides derived from K(b) contribute to the induction of tolerance, retroviruses carrying mutant K(b) genes designed to enter separate pathways of Ag presentation were constructed. Thymectomized and CD8 T cell-depleted mice that had been irradiated and reconstituted with bone marrow cells expressing a secreted form of K(b) showed prolongation of K(b) disparate skin graft survival. Skin graft prolongation was not observed when similar experiments were performed using mice that were not CD8 T cell depleted. This suggests that hyporesponsiveness can be induced in CD4 T cells, but not CD8 T cells by Ags presented via the exogenous pathway of Ag processing. Modest prolongation of skin allografts was observed in mice reconstituted with bone marrow cells transduced with retroviruses carrying a gene encoding a mutant K(b) molecule expressed only in the cytoplasm. Prolongation was also observed in similar experiments in mice that were thymectomized and CD4 T cell depleted following complete reconstitution, but not in mice that were reconstituted and then thymectomized and CD8 T cell depleted. Thus, hyporesponsiveness can be induced in a subset of CD8 T cells by recognition of peptides derived from K(b) through both the direct and indirect pathways of Ag recognition, while CD4 T cell hyporesponsiveness to MHC class I disparate grafts occurs only through the indirect pathway of Ag recognition.

3T3 Cells↗
PubMed2000

Pathologic findings and prostate specific antigen outcome after radical prostatectomy for patients diagnosed on the basis of a single microscopic focus of prostate carcinoma with a gleason score </= 7.

BACKGROUND: Whether patients who are diagnosed on the basis of a single microscopic focus of prostate carcinoma with a Gleason score </= 7 (micro PC) have potentially life-threatening disease if they are not treated is unknown. METHODS: Pathologic findings and prostate specific antigen (PSA) outcome after radical prostatectomy (RP) for men who were diagnosed with micro PC were determined. Of 917 patients who were managed with RP during 1989-1999 at the Brigham and Women's Hospital, 66 patients (7%) were diagnosed on the basis of micro PC. Pathologic stage, tumor grade, tumor volume, margin status, and PSA outcome were investigated and are reported. Estimates of PSA outcome were calculated using the actuarial method of Kaplan and Meier. Pairwise comparisons were made using the log rank test. RESULTS: The finding of micro PC at biopsy was associated with macroscopic disease (involving at least half of a single lobe) in 92% of the patients in this series. Although these men had favorable pathologic findings (94% had organ confined disease, 89% had negative tumor margins, and 79% had a prostatectomy Gleason score </= 6), approximately 10% of the patients failed biochemically within 5 years after RP. CONCLUSIONS: The finding of micro PC at biopsy should not be used as a surrogate for clinically insignificant disease.

Biopsy↗
PubMed2000

CD45 opposes beta-amyloid peptide-induced microglial activation via inhibition of p44/42 mitogen-activated protein kinase.

Reactive microglia have been suggested to play a role in the Alzheimer's disease (AD) process, and previous studies have shown that expression of CD45, a membrane-bound protein-tyrosine phosphatase (PTP), is elevated in microglia in AD brain compared with controls. To investigate the possible role of CD45 in microglial responsiveness to beta-amyloid (Abeta) peptides, we first co-treated primary cultured microglia with a tyrosine phosphatase inhibitor [potassium bisperoxo (1,10-phenanthroline) oxovanadate (phen), 5 micrometer] and freshly solubilized Abeta peptides (1000 nm). Data show synergistic induction of microglial activation as evidenced by tumor necrosis factor alpha (TNF-alpha) production and nitric oxide (NO) release, both of which we show to be dependent on activation of p44/42 mitogen-activated protein kinase (MAPK). Furthermore, co-treatment with phen and Abeta peptides results in microglia-induced neuronal cell injury. Stimulation of microglial CD45 by anti-CD45 antibody markedly inhibits these effects via inhibition of p44/42 MAPK, suggesting that CD45 is a negative regulator of microglial activation. Accordingly, primary cultured microglia from CD45-deficient mice demonstrate hyper-responsiveness to Abeta, as evidenced by TNF-alpha release, NO production, and neuronal injury after stimulation with Abeta peptides. As a validation of these findings in vivo, brains from a transgenic mouse model of AD [transgenic Swedish APP-overexpressing (Tg APP(sw)) mice] deficient for CD45 demonstrate markedly increased production of TNF-alpha compared with Tg APP(sw) mice. Taken together, these results suggest that therapeutic agents that stimulate the CD45 PTP signaling pathway may be effective in suppressing microglial activation associated with AD.

Alzheimer Disease↗