Search PubMed⌕ Search

Biomedical subjects

D Yang

Publications and source records attributed to D Yang.

At least 163 records · Page 9Linked to original sources
PubMed2000

[Washing liquid cytology examination of operative wound in patients with breast tumor].

OBJECTIVES: To study the relation between exfoliated tumor cells in operative wound and clinical pathologic classification and to provide theory for killing exfoliated tumor cells in operation. METHOD: Washing liquid cytology examination of the operative wound was done in 262 patients with breast tumor. The relation between cytology examination and pathological classification was analyzed. RESULTS: In the 262 patients, exfoliated tumor cells were found in 63 patients, (24%). The detection rate in patients with I, II, III and IV stage was 5.3%, 27.1%, 79.3% and 100% respectively; The rate for T(1), T(2), T(3) stage was 6.1%, 18.9% and 51.3% respectively. The detection rate was 58.6% when the number of metastasis lymph node beyond 3; the rate was 14.3% and 14.1% respectively when the number below 3 or no lymphatic metastasis. CONCLUSION: The detection rate of exfoliated tumor cells is related to tumor advance, and it is necessary to kill exfoliated tumor cells in operation.

Breast Neoplasms↗
PubMed2000

[Mitogenesis of platelet-derived growth factors to human osteoblasts modulated by basic fibroblast growth factor].

OBJECTIVES: To investigate the mechanism by which basic fibroblast growth factor modulates the mitogenesis of platelet-derived growth factor to human osteoblasts. METHODS: The osteoblasts isolated from human fetal calvaria were incubated with PDGF-AB (100 ng/ml) or bFGF(10 ng/ml) combined with PDGF-AB (100 ng/ml); the growth curve was plotted. The(3)H-TdR incorporation of the osteoblasts was measured after the cells were incubated with different combination of bFGF and PDGF-AA or PDGF-BB. After incubated with bFGF (10 ng/ml) for 24 hours, the number of PDGFR-alpha and PDGFR-beta on the membrane of the osteoblasts was detected by fluoroimmunoassay. RESULTS: Four days after PDGF-AB added into the medium, the population of the osteoblasts was larger than that of the control (P < 0.05). The number of the osteoblasts incubated with PDGF-AB (12.1 x 10(4)) was 1.8 times as large as the control (6.8 x 10(4)) in the 10th day (P < 0.05), and that of the osteoblasts incubated with both bFGF and PDGF-AB increased more quickly than the cells only incubated with PDGF-AB. The incorporation of (3)H-TdR into the osteoblasts cultured with bFGF combined with PDGF-AA (533.6 +/- 13.1) was more than that cultured only with PDGF-AA (435.4 +/- 14.8, P < 0.01), so was the incorporation of (3)H-TdR of those cells cultured with bFGF and then PDGF-AA (633.8 +/- 51.5). bFGF up-regulated PDGFR-alpha and down-regulated PDGFR-beta on the surface of the human osteoblasts. CONCLUSION: bFGF elevates the mitogenesis of PDGF-AA or -AB to human osteoblasts by up-regulating PDGFR-alpha.

Cell Proliferation↗
PubMed2000

[Effect of yimai jiangya extract on plasma neuropeptide Y level in patients of senile hypertension with qi-deficiency and blood stasis syndrome].

OBJECTIVE: To observe the effect of Yimai Jiangya extract (YMJYE) on plasma neuropeptide Y (NPY) level in patients of senile hypertension at stage II with Qi-Deficiency and blood stasis Syndrome (QDBSS). METHODS: Sixty-eight patients were randomly divided into two groups, 36 patients in the treated group treated with YMJYE and 32 patients in the control group treated with captopine. Radioimmunoassay was used to examine the level of plasma NPY before and after treatment in the two groups. RESULTS: Before treatment, plasma NPY level was significantly higher in both groups than that in the old healthy persons (P < 0.01), it lowered significantly after treatment and the decrement was more obvious in the treated group in comparing with that in the control group (P < 0.01). Blood pressure was significantly lowered in both groups after treatment (P < 0.01) but with no significant difference between them. CONCLUSION: Plasma NPY level was increased in patients of senile hypertension with QDBSS. YMJYE had good effect in lowering plasma NPY level and reducing blood pressure. It is presumed that the NPY lowering effect of YMJYE might be one of its mechanisms in lowering blood pressure.

Aged↗
PubMed2000

[17beta -estradiol induced nitric oxide release in vascular endothelial cells].

Bovine aortic endothelial cells (BAECs) were used to study the effect of 17beta -estradiol (E(2)) on nitric oxide (NO) release, nitric oxide synthase (eNOS) mRNA expression and intracellular free calcium con~cen~tration ([Ca(2+)](I)) and modulation of the effect of E(2) by estrogen receptor (ER) antagonist tamoxifen and NOS inhibitor L-NAME. E(2) (10(-12) 10(-8) mol/L) induced NO release of BAECs in a concentration-dependent manner and the abundant expression of eNOS mRNA in BAECs increased obviously after treatment with E(2) (10(-8)mol/L) for 48 h. These effects were evidently inhibited by tamoxifen (10(-7)mol/L) and L-NAME (10(-6) mol/L). Furthermore treatment with E(2) (10(-8) mol/L) for 48 h significantly increased the resting [Ca(2+)](I) and the rise of [Ca(2+)](I) induced by ATP in BAECs. These results suggest that E(2)-induced NO release and eNOS mRNA expression in BAECs may be mediated by ER and related to calcium mobilization.

Animals↗
PubMed2000

[Determination of lidocaine in human spinal cord by high-performance liquid chromatography].

A RPHPLC method for determining lidocaine in human's spinal cord. Was established. The linear range of the method was 0.20-20.0 micrograms/ml(r = 0.9999). The detection limit was 0.02 ng/ml(S/N > or = 3) and the clean-up recovery of lidocaine in human spinal cord was 82.4%-92.7%. The CV% were no more than 6.0% (N = 4). No interfere by other compounds was observed in study results using this method. RPHPLC method shows an excellent recovery, high sensitivity and good precision.

Anesthesia, Epidural↗
PubMed2000

[Clinical retrospect on autoimplantation of traumatically dislocated teeth].

OBJECTIVE: A total of 48 cases with autoimplantation of traumatically dislocated teeth were retro spected as clinical references. METHODS: Several indexes were recorded in details, for instance, tooth dislocation time, operation and postoperative management and patients were followed up periodically. RESULTS: Tooth dislocating intervals from trauma to implantation were from 0.5 to 48 hours. Therapeutic effectiveness was graded as perfect in 37 teeth (61.7%), good in 18 (30.0%) and poor in 5 teeth (8.3%), in which 3 teeth were extracted within 1 year. Three-year success rate was 83.0%, and five-year success rate was 61.7%. It was judged 20 teeth being as periodontal membranous healing, 35 bony healing and 5 fibrous healing. Pulpal vitality tests were positive in 23 and negative in 37 teeth. Root canal therapies were conducted in 20 teeth. CONCLUSION: Carefully protecting periodontal membranes, keeping good fixation, preventing from infection and avoiding occlusal injuries are important factors for successful implantation of the dislocated teeth. Periodical examination would be benefit to the long term prognosis. The correct methods for dislocated tooth preservation should be treated as the important part of health education.

Adolescent↗
PubMed2000

[Study on lipids and other volatile constituents in Pheretima aspergillum].

To study chemical constituents in Pheretima aspergillum, three kinds of fractions were obtained from this drug by soxhlet extraction with different solvents, and the chemical structures of thirty-six volatile components were identified by means of GC-MS. The eleven in ether fraction were all lipids and the relative content of non-saturated fatty acid was the highest(27.70%) such as oleic acid, linoleic acid, arachidonic acid and eicosatrienoic acid; There were eight lipids in acetone fraction (35.75%), which included one kind of nonsaturated fatty acid (linoleic acid); There were thirteen lipids in ethanol fraction (72.09%), which non-saturated fatty acid has never been detected. This study has determined the lipid composition in Pheretima aspergillum, especially non-saturated fatty acid, and afforded chemical base to cardio-cerebro-vascular therapy.

Animals↗
PubMed2000

[Chemical composition of essential oil in stems, leaves and flowers of Agastache rugosa].

The chemical components and their relative contents of essential oil in different parts (stems, leaves and flowers) of Agastache rugosa have been analyzed by GC-MS technique, and 32 kinds of chemical structures in these three kinds of oils have been identified. Among which, it included 24 kinds in leaf-oil, 27 in stem-oil and 22 in flower-oil. The principal components in all these three kinds of oils were methylchavicol (60.01-88.43%), and other important components were d-limonene, caryophyllene, hexadecanoic acid, linoleic acid, octahydro-7-methyl-methylene-4-(1-methylethyl)-1H-cyclopenta [1, 3] cyclopropa [1, 2] benzene, etc.

Agastache↗
PubMed2000

[Study on the inhibitory activity, in vitro, of baicalein and baicalin against skin fungi and bacteria].

In this paper, we concentrated in examining, in vitro, the antiseptic activity of the baicalein and baicalin upon the seventeen pathogenic skin fungal and sixteen skin bacterial strains, these two flavonic compounds were known principally as the biosubstances of a traditional Chinese medicinal plant: Scutellaria baicalensis. In agar media, the baicalein possessed potent specific activity against the pathogenic yeasts with MICs of 70-100 micrograms/ml; But in the same condition, no inhibitory effect was observed upon dermatophytes and filamentous imperfect fungi for baicalein, and upon all used strains for baicalin. According to the antibacterial test of baicalein, a high efficacy was achieved against certain causative specie of axillary and foot's odour such as Micrococcus sedentarius, Staphylococcus epidermidis, S. hominis and C. xerosis with a MICs inferior to 250 micrograms/ml. The good inhibitory activity of baicalein could be linked to the group hydroxyl (-OH) in position seven of the molecule.

Anti-Infective Agents, Local↗
PubMed2000

[Investigation of the nasal T/NK cell lymphomas in 14 cases].

OBJECTIVE: To study the biologic behavior, pathologic features as well as clinic manifestations of the nasal T/NK cell lymphomas, and to provide experiences for the diagnosis and treatment of the tumor. METHODS: Specimens of 23 cases lethal midline granulomas (LMG) were examined: (1) HE stain for immunohistochemical staining for TIA-1, CD43, CD20, CD3 epsilon, CD56 and in situ hybridization for EBV encoded small nuclear RNA(EBER1/2, Y017, DAK0). (2) The cases histories were reviewed. RESULTS: (1) 14 cases were confirmed by histological features. In the 14 cases, tumor cells expressed TIA-1, CD56, CD3 epsilon, CD43, EBER1/2 positive. (2) Among them 8 cases (57%) showed special clinic features of LMG, Nasopharynx, pharynx and laryngeal involvement were found in other 6 cases. One case revealed lymphoid leukemia. In other 2 cases, gastrointestinal tract were involved. Hemophagocytic syndrome (HPS) complication happened in 1 case. CONCLUSION: The tumor cells of nasal T/NK cell lymphomas expressed TIA-1, CD56, CD43, CD3 epsilon may suggest it originates from NK cell. The high association with EBV may suggest in situ hybridization. 57% patients showed that the special clinic features of the LMG, and gastrointestinal tract, bone marrow, peripheral blood were involved in some cases. One case complicated with hemophagocytic syndrome (HPS).

Herpesvirus 4, Human↗
PubMed2000

[The influences of human apolipoprotein E mutants on the learning and memory of cerebral cortex in transgenic mice].

OBJECTIVE: To study the influences of the mutants of human apolipoprotein E on the function of cerebral cortex. METHODS: The Southern blot hybridization and ELISA techniques were used for identification of integration and expression of human apoE4 and apoE7 genes at the mice chromosome and in the serum of F1 transgenic mice. Then the active avoidance response test was performed to determine the alteration of learning and short term and long term memory of the transgenic mice. The serum total cholesterol (TC) and triglyceride (TG) were determined simultaneously with enzymatic procedure. RESULTS: (1) In F1 transgenic mice the human apoE genes integrated at the chromosome and expressed in their serum stably. (2) In apoE4 mice the learning and short term memorizing abilities were decreased, and in apoE7 mice the short term memorizing abilities were decreased as well. In addition, the TC and TG increased statistically. CONCLUSIONS: The overexpression of human apoE4 and apoE7 genes in transgenic mice could damage the function of cerebral cortex. It denoted that the mutations of apoE might correlate the pathogenesis of Alzheimer's disease.

Animals↗
PubMed1999

Structural and functional analysis of the 5' untranslated region of coxsackievirus B3 RNA: In vivo translational and infectivity studies of full-length mutants.

The lengthy 5' untranslated region (5'UTR) of coxsackievirus B3 (CVB3) forms a highly ordered secondary structure, which plays an important role in controlling viral transcription and translation. Our previous work has delineated the internal ribosome entry site (IRES) by mutation of mono- and bicistronic plasmids containing the 5'UTR and subsequent cell- free translation in rabbit reticular lysate (D. Yang, J. E. Wilson, D. R. Anderson, L. Bohunek, C. Cordeiro, R. Kandolf, and B. M. McManus. (1997). Virology 228, 63-73). To further identify the sequence elements responsible for viral translation and infectivity in tissue culture cells, >30 full-length mutants of CVB3 were constructed by mutations of the IRES and its flanking regions. Viral RNAs were transcribed from these constructs and transfected into HeLa cells. When the stem-loops G and H in the putative IRES were deleted, viral infectivity was abolished and viral protein translation was also undetectable by immunoblot analysis. However, when stem-loops A and B were deleted or stem-loop E was partially deleted, viral protein translation could be detected although cytopathic effect could not be observed. The data suggest that the crucial sequence of the IRES is located at stem-loops G and H. Further serial deletion mapping up and down stream of the crucial sequence defined more accurately the 5' and 3' boundaries of the IRES, located at nucleotides (nts) 309-432 and 639-670, respectively. These results indicate that the core sequence of the IRES should be located at nts 432-639. This IRES segment is much shorter and located closer to the initiation codon than that of poliovirus. To further define critical nucleotides within the IRES core, site-directed mutagenesis was conducted at the IRES core sequence by PCR. A 46-nt deletion in the pyrimidine-rich tract of stem-loop G abolished viral translation and infectivity. Interestingly, five single-nt substitutions in the pyrimidine-rich tract aimed at destabilizing the base pairing between the viral IRES and host 18S rRNA did not abolish CVB3 infectivity although viral protein translation was significantly reduced. This finding suggests that ribosomal internal initiation of translation and viral infectivity not only may require RNA secondary structure but also may need tertiary structure and perhaps the assistance of host protein factors.

5' Untranslated Regions↗
PubMed1999

Novel mode of ligand binding by the SH2 domain of the human XLP disease gene product SAP/SH2D1A.

BACKGROUND: The Src homology 2 (SH2) domains of cytoplasmic signaling proteins generally bind phosphotyrosine (pTyr) sites in the context of carboxy-terminal residues. SAP (also known as SH2D1A or DSHP), the product of the gene that is mutated in human X-linked lymphoproliferative (XLP) disease, comprises almost exclusively a single SH2 domain, which may modulate T-cell signaling by engaging T-cell co-activators such as SLAM, thereby blocking binding of other signaling proteins that contain SH2 domains. The SAP-SLAM interaction can occur in a phosphorylation-independent manner. RESULTS: To characterize the interaction between SAP and SLAM, we synthesized peptides corresponding to the SAP-binding site at residue Y281 in SLAM. Both phosphorylated and non-phosphorylated versions of an 11-residue SLAM peptide bound SAP, with dissociation constants of 150 nM and 330 nM, respectively. SLAM phosphopeptides that were truncated either at the amino or carboxyl terminus bound with high affinity to SAP, suggesting that the SAP SH2 domain recognizes both amino-terminal and carboxy-terminal sequences relative to the pTyr residue. These results were confirmed by nuclear magnetic resonance (NMR) studies on (15)N- and (13)C-labeled SAP complexed with three SLAM peptides: an amino-terminally truncated phosphopeptide, a carboxy-terminally truncated phosphopeptide and a non-phosphorylated Tyr-containing full-length peptide. CONCLUSIONS: The SAP SH2 domain has a unique specificity. Not only does it bind peptides in a phosphorylation-independent manner, it also recognizes a pTyr residue either preceded by amino-terminal residues or followed by carboxy-terminal residues. We propose that the three 'prongs' of a peptide ligand (the amino and carboxyl termini and the pTyr) can engage the SAP SH2 domain, accounting for its unusual properties. These data point to the flexibility of modular protein-interaction domains.

Adaptor Proteins, Signal Transducing↗
PubMed1999

TbetaR-I(6A) is a candidate tumor susceptibility allele.

We have previously described a type I transforming growth factor (TGF)-beta receptor (TbetaR-I) polymorphic allele, TbetaR-I(6A), that has a deletion of three alanines from a nine-alanine stretch. We observed a higher than expected number of TbetaR-I(6A) homozygotes among tumor and nontumor DNA from patients with a diagnosis of cancer. To test the hypothesis that TbetaR-I(6A) homozygosity is associated with cancer, we performed a case-control study in patients with a diagnosis of cancer and matched healthy individuals with no history of cancer and who were identical in their gender and their geographical and ethnic background to determine the relative germ-line frequencies of this allele. We found nine TbetaR-I(6A) homozygotes among 851 patients with cancer. In comparison, there were no TbetaR-I(6A) homozygotes among 735 healthy volunteers (P < 0.01). We also observed an excess of TbetaR-I(6A) heterozygotes in cancer cases compared to controls (14.6% versus 10.6%; P = 0.02, Fisher's exact test). A subset analysis revealed that 4 of 112 patients with colorectal cancer were TbetaR-I(6A) homozygotes (P < 0.01). Using mink lung epithelial cell lines devoid of TbetaR-I, we established stably transfected TbetaR-I and TbetaR-I(6A) cell lines. We found that, compared to TbetaR-I, TbetaR-I(6A) was impaired as a mediator of TGF-beta antiproliferative signals. We conclude that TbetaR-I(6A) acts as a tumor susceptibility allele that may contribute to the development of cancer, especially colon cancer, by means of reduced TGF-beta-mediated growth inhibition.

Activin Receptors, Type I↗
PubMed1999

Structural requirements for Tyr in the consensus sequence Y-E-N of a novel nonphosphorylated inhibitor to the Grb2-SH2 domain.

The phage library derived, nonphosphorylated and thioether-cyclized peptide, termed G1TE, cyclo(CH(2)CO-Glu(1)-Leu-Tyr(3)-Glu-Asn-Val-Gly-Met-Tyr-Cys(10))-amid e, represents a new structural motif that binds to the Grb2-SH2 domain in a pTyr-independent manner, with an IC(50) of 20 microM. The retention of binding affinity is very sensitive with respect to peptide ring-size alterations and Ala mutations. We demonstrated previously that the Glu(1) side chain and its closely related analogs partially compensate for the absence of the phosphate functionality on Tyr(3), and, based on molecular modeling, these acidic side-chains complex with the Arg67 and Arg86 side-chains of the protein in the binding cavity. In this study we judiciously altered and incorporated various natural and unnatural amino acids as Tyr replacements within the -YEN- motif, and we demonstrate the functional importance and structural requirement of Tyr(3) for effective binding of this novel non-phosphorylated ligand to the Grb2-SH2 domain. The phenyl side-chain moiety and a polar functional group with specific orientation in position Y(3) of the peptide are particularly required. Using SPR binding assays, a submicromolar inhibitor (IC(50) = 0.70 microM) was obtained when Glu(1) was replaced with alpha-aminoadipate and Tyr(3) was replaced with 4-carboxymethyl-Phe, providing peptide 14, G1TE(Adi(1), cmPhe(3)). Peptide 14 also inhibited Grb2/p185(erb)(B-2) protein association in cell homogenates of erbB-2-overexpressing MDA-MA-453 cancer cells at near one micromolar concentrations.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Beta-defensins: linking innate and adaptive immunity through dendritic and T cell CCR6.

Defensins contribute to host defense by disrupting the cytoplasmic membrane of microorganisms. This report shows that human beta-defensins are also chemotactic for immature dendritic cells and memory T cells. Human beta-defensin was selectively chemotactic for cells stably transfected to express human CCR6, a chemokine receptor preferentially expressed by immature dendritic cells and memory T cells. The beta-defensin-induced chemotaxis was sensitive to pertussis toxin and inhibited by antibodies to CCR6. The binding of iodinated LARC, the chemokine ligand for CCR6, to CCR6-transfected cells was competitively displaced by beta-defensin. Thus, beta-defensins may promote adaptive immune responses by recruiting dendritic and T cells to the site of microbial invasion through interaction with CCR6.

Antibodies↗