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Biomedical subjects

H Ding

Publications and source records attributed to H Ding.

At least 73 records · Page 4Linked to original sources
PubMed2000

Genetic polymorphism of RhD-negative associated haplotypes in the Chinese.

The Rh blood group is the most polymorphic human blood group system, and is clinically significant in transfusion medicine. Individuals are classified as Rh-positive and Rh-negative depending on the presence or absence of the D antigen on the red cell surface. The RhD-negative trait could be generated by multiple genetic mechanisms, which have been shown to be ethnic group-dependent. In this study, we evaluated the status of seven RHD-specific exons (exons 3, 4, 5, 6, 7, 9, and 10) and RH intron 4 in 119 Chinese blood donors, using the sequence-specific primers polymerase chain reaction (SSP-PCR). Of the 87 individuals who were RhD-negative, 52 with the ce/ce, ce/cE, or Ce/ce genotype (60%) lacked the above seven RHD exons; 22 with the Ce/Ce or Ce/ce genotype (25%) had all the RHD exons examined; 13 with the Ce/ce genotype (15%) carried at least one RHD exon. Antigen association analysis suggested the existence of a novel class of RhD-negative associated haplotypes in the Chinese, tentatively denoted D(nf)Ce. The D(nf)Ce haplotype consisted of a normal RHCe allele and a nonfunctional RHD gene, which vary depending on the structure of the RHD gene. Among the RhD-negative Chinese, the estimated frequencies of the dce, dCe, and D(nf)Ce haplotypes were 0.7500, 0.0465, and 0.2035, respectively. No statistically significant deviation from Hardy-Weinberg equilibrium was observed using this genetic model.

China↗
PubMed2000

The mouse Pdgfc gene: dynamic expression in embryonic tissues during organogenesis.

The signaling activity of Platelet-derived growth factors A and B (PDGF-A and PDGF-B) that is mediated through the two receptor kinases, PDGFR-alpha and PDGFR-beta has been shown to be critical for the development of the cardiovascular organs, the kidney, the lung and the central nervous system. During the cloning of genes for VEGF related proteins, we isolated a mouse cDNA that can encode for a protein of 345 amino acids. A comparison of the amino acid sequence reveals that this predicted gene product displays 95% identity to human PDGF-C. The mouse Pdgfc gene maps to a region of chromosome 17 that is syntenic to human chromosome 6p21.3 In E9. 5-E15.5 mouse embryo, Pdgfc is widely expressed in the surface ectoderm and later in the germinal layer of the skin, the olfactory and otic placode and their derivatives and the lining of the oral cavity. In the gut and visceral organs, such as the lung and the kidney, Pdgfc mRNA is first expressed in the endodermal epithelium and later in mesenchymal tissues associated with the endodermal structures. Similar to other PDGFs, Pdgfc is widely expressed in mesenchymal precursors and the myoblast of the smooth and skeletal muscles. Contrary to PDGF-A, Pdgfc is not expressed in the central nervous system, except in the cerebellum, and neurogenic derivatives of the neural crest cells. Pdgfc is also absent from the heart and the vascular endothelium

Amino Acid Sequence↗
PubMed2000

Potassium- and acetylcholine-induced vasorelaxation in mice lacking endothelial nitric oxide synthase.

1. The contribution of an endothelium-derived hyperpolarizing factor (EDHF) was investigated in saphenous and mesenteric arteries from endothelial nitric oxide synthase (eNOS) (-/-) and (+/+) mice. 2. Acetylcholine-induced endothelium-dependent relaxation of saphenous arteries of eNOS(-/-) was resistant to N(omega)-nitro-L-arginine (L-NNA) and indomethacin, as well as the guanylyl cyclase inhibitor, 1H-(1,2,4)oxadiazolo(4,3-a) quinoxalin-1-one(ODQ). 3. Potassium (K(+)) induced a dose-dependent vasorelaxation which was endothelium-independent and unaffected by either L-NNA or indomethacin in both saphenous and mesenteric arteries from eNOS(-/-) or (+/+) mice. 4. Thirty microM barium (Ba(2+)) and 10 microM ouabain partially blocked potassium-induced, but had no effect on acetylcholine-induced vasorelaxation in saphenous arteries. 5. Acetylcholine-induced relaxation was blocked by a combination of charybdotoxin (ChTX) and apamin which had no effect on K(+)-induced relaxation, however, iberiotoxin (IbTX) was ineffective against either acetylcholine- or K(+)-induced relaxation. 6. Thirty microM Ba(2+) partially blocked both K(+)- and acetylcholine-induced relaxation of mesenteric arteries, and K(+), but not acetylcholine-induced relaxation was totally blocked by the combination of Ba(2+) and ouabain. 7. These data indicate that acetylcholine-induced relaxation cannot be mimicked by elevating extracellular K(+) in saphenous arteries from either eNOS(-/-) or (+/+) mice, but K(+) may contribute to EDHF-mediated relaxation of mesenteric arteries.

Acetylcholine↗
PubMed2000

[Effect of heparinoid derived from porcine duodenum on the proliferation of cultured smooth muscle cells].

AIM: To study the antiproliferative effect of haparinoid derived from porcine duodenum (heparinoid) on cultured vascular smooth muscle cells. METHODS: Cultured bovine aortic smooth muscle cells (BASMCs) of 5-10 passages were seeded into 24 and 72-well cluster culture plates and were synchronized by 48 h serum deprivation. Then, the cells were re-stimulated by serum repletion with or without heparinoid. The antiproliferative effect of heparinoid was evaluated by crystal violet staining and MTT assay 72 h after serum repletion. To study the drug action on cytomorphological changes, three kinds of cells [quiescent cells, cells treated with 10% fetal calf serum (FCS) with or without heparinoid] were observed by transmission electron microscopy. After synchronized and re-stimulated as above, BASMCs were treated with heparinoid 0.8 mg.mL-1 at selected points during serum repletion. The cells were harvested at specified times after serum repletion, then cellular DNA contents (to estimate the proportions of cells in different phases of the cell cycle) and the contents of alpha-actin, c-myc and c-fos proteins were measured by flow cytometry. RESULTS: Heparinoid was shown to inhibit the proliferation of BASMCs induced by 10% FCS. The inhibitory effect was weakened when heparinoid was added 2 h after serum repletion, and there was no antiproliferative effect when heparinoid was added 12 h after serum repletion. Electron micrographs showed that cells treated with 10% FCS and heparinoid expressed a contractile phenotype, while cells treated with 10% FCS only expressed a synthetic phenotype. Flow cytometry study showed remarkable increase of alpha-actin, and decrease of c-myc and c-fos proteins in the cells treated with heparinoid. CONCLUSION: Heparinoid was found to inhibit the proliferation of BASMCs. The antiproliferative effect occurred at the early phase of the cell cycle. It might be due to the drug's influence on cell phenotype modulation and the down regulation of c-myc and c-fos proto-oncogenes expression.

Animals↗
PubMed2000

[Effects of elective cesarean section and antibiotics to the bacterial flora in female genital tract].

OBJECTIVE: To study the effects of elective cesarean section and antibiotics to the bacterial flora in the normal female genital tract. METHODS: Forty-five cases of elective cesarean section were randomly divided into 3 groups: no antibiotic was given (group A), one antibiotic was given for three days (group B), and only once antibiotic was used (group C). Bacterial cultures of vaginal swab and specimens aspirated from uterine cavity were performed in each case before and after operation to supervise the changes of bacterial flora in genital tract and postoperative infection. RESULTS: The positive rate of bacterial culture was 35.71% before operation but 64.29% after operation (P < 0.01). The numbers of aerobe and anaerobe were 3 and 10 strains, respectively, before operation, and 16 and 18 strains after operation. The counts of anaerobe were more than those of aerobe in group A either before or after operation in group A. The counts of aerobe, on the other hand, were more than those of anaerobe both in group B and C after operation. The rates of positive bacterial culture in uterine cavity after operation were similar among the three groups (P > 0.05). Interestingly the operative infection rates were 6.67% evenly. CONCLUSIONS: Both cesarean section and antibiotics may disturb the bacterial flora in the normal female genital tract. The disturbance may increase the chance for flora imbalance and the postoperative infection. There was a great need for rational application of prophylactic antibiotics after cesarean section. Single-dose antibiotic during cesarean section should be advocated.

Anti-Bacterial Agents↗
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

[Sarcomatoid carcinoma in breast].

OBJECTIVE: To observe the distinctive pathomorphological features of sarcomatoid carcinoma (SC) in mammary gland as well as its diagnosis and differential diagnosis. METHODS: 1 538 malignant tumors of the breast were reviewed. 15 cases (0.98%) were diagnosed as SC. AE1/AE3, carcinoembryonic antigen (EMA), vimentin, S-100 protein, actin, estrogen receptor (ER) and progesterone (PR) were performed with SP immunohistochemical staining methods. RESULTS: The SC were divided into four morphological types according to the distinctive features of their sarcomatoid components. (1) Polymorphic sarcoma type: sarcomatoid components are polymorphic; (2) Spindle cell type: sarcomatoid components consisted of spindle cells; (3) Osteoclastic giant cell type: a huge number of osteoclastic giant cells in the sarcomatoid components; (4) Myxocartilage type: myxocartilaginoid components are seen in the tumor tissue. With immunohistochemical staining, the expression rates of AE1/AE3, EMA, vimentin, S-100 protein and actins in the epithelial components were in 11, 15, 11, 12 and 8 cases respectively, and sarcomatoid components were in 10, 13, 13, 13 and 10 cases respectively, while ER and PR were positive only in 2 cases. CONCLUSION: Sarcomatoid carcinoma of the breast should be distinguished from carcinosarcoma, desmoplastic carcinoma, sarcoma, nodular fasciitis and fibromatosis.

Actins↗
PubMed2000

[The influence of probe geometry on the sensitivity of tissue oximeter using near infra-red spectroscopy].

Based on the modified Lambert-Beer law under scattering media, near infra-red spectroscopy tissue oximeter measures the changes of absorber concentrations (such as oxy-hemoglobin, deoxy-hemoglobin, cytochrome aa3). This is made possible by recording the optical density change under different physiological status. This paper describes the average penetration depth, average photon path-length and spatial sensitive profile in multi-layered tissue model using Monte-Carlo method. The result shows the probe geometry of the sensor, which is the separation between the light source and the detector, has a great influence on the sensitivity of measurement. Increasing this separation properly allows the improvement of the sensitivity of measurement and the increase of the probability of looking at oxygenation deep under the surface tissue. But this improvement is limited by the decrease of signal-noise ratio. Optimum probe spacing should be estimated for special tissue structure.

Humans↗
PubMed1999

Nucleotide sequence of the partially deleted D4Z4 locus in a patient with FSHD identifies a putative gene within each 3.3 kb element.

Facioscapulohumeral muscular dystrophy (FSHD) is linked to the polymorphic D4Z4 locus on chromosome 4q35. In non-affected individuals, this locus comprises 10-100 tandem copies of members of the 3.3kb dispersed repeat family. Deletions leaving 1-8 such repeats have been associated with FSHD, for which no candidate gene has been identified. We have determined the complete nucleotide sequence of a 13.5kb EcoRI genomic fragment comprising the only two 3.3kb elements left in the affected D4Z4 locus of a patient with FSHD. Sequence analyses demonstrated that the two 3.3kb repeats were identical. They contain a putative promoter that was not previously detected, with a TACAA instead of a TATAA box, and a GC box. Transient expression of a luciferase reporter gene fused to 191bp of this promoter, demonstrated strong activity in transfected human rhabdomyosarcoma TE671 cells that was affected by mutations in the TACAA or GC box. In addition, these 3.3kb repeats include an open reading frame (ORF) starting 149bp downstream from the TACAA box and encoding a 391 residue protein with two homeodomains (DUX4). In-vitro transcription/translation of the ORF in a rabbit reticulocyte lysate yielded two (35)S Cys/ (35)S Met labeled products with apparent molecular weights of 38 and 75kDa on SDS-PAGE, corresponding to the DUX4 monomer and dimer, respectively. In conclusion, we propose that each of the 3.3kb elements in the partially deleted D4Z4 locus could include a DUX4 gene encoding a double homeodomain protein.

Amino Acid Sequence↗
PubMed1999

Functional interactions between Sp1 or Sp3 and the helicase-like transcription factor mediate basal expression from the human plasminogen activator inhibitor-1 gene.

Basal expression of the human plasminogen activator inhibitor-1 (PAI-1) is mediated by a promoter element named B box that binds the helicase-like transcription factor (HLTF), homologous to SNF/SWI proteins. Electrophoretic mobility shift assays performed on a set of B box point mutants demonstrated two HLTF sites flanking and partially overlapping with a GT box binding Sp1 and Sp3. Mutations affecting either the Sp1/Sp3 or the two HLTF sites inhibited by 6- and 2.5-fold, respectively, transient expression in HeLa cells of a reporter gene fused to the PAI-1 promoter. In Sp1/Sp3-devoid insect cells, co-expression of PAI-1-lacZ with Sp1 or Sp3 led to a 14-26-fold induction while HLTF had no effect. Simultaneous presence of Sp1 or Sp3 and the short HLTF form (initiating at Met-123) provided an additional 2-3-fold synergistic activation suppressed by mutations that prevented HLTF binding. Moreover, a DNA-independent interaction between HLTFMet123 and Sp1/Sp3 was demonstrated by co-immunoprecipitation from HeLa cell extracts and glutathione S-transferase pull-down experiments. The interaction domains were mapped to the carboxyl-terminal region of each protein; deletion of the last 85 amino acids of HLTFMet123 abolished the synergy with Sp1. This is the first demonstration of a functional interaction between proteins of the Sp1 and SNF/SWI families.

Binding Sites↗
PubMed1999

Potent and orally bioavailable noncysteine-containing inhibitors of protein farnesyltransferase.

Potent and orally bioavailable nonthiol-containing inhibitors of protein farnesyltransferase are described. Oral bioavailability was achieved by replacement of the pyridyl ether moiety of 1 with a 2-substituted furan ether to give 4. Potency was regained with 2,5-disubstituted furan ethers while maintaining the bioavailability inherent in 4. p-Chlorophenylfuran ether 24 is 0.7 nM in vitro (FTase) and is 32% bioavailable in the mouse, 30% bioavailable in rats, and 21% bioavailable in dogs.

Alkyl and Aryl Transferases↗
PubMed1999

[Effects of passive smoking on menstrual function of perimarital women].

To study the effects of passive smoking on menstrual function of perimarital women, 3466 premarital women in Beijing were investigated by questionnaire on their general health, occupations lifestyles, smoking and passive smoking habits, nutrition, environmental exposure and menstrual functions. The data was analyzed by Logistic regression statistics and the results showed that passive smoking at home and at work was positively associated with menstrual dysfunction and dysmenorrhea (P < 0.01) and there was a dose-response relationship (P < 0.05). The results showed that passive smoking, especially at work, can cause menstrual dysfunction of the perimarital women. It is harmful to reproductive health of the childbearing age women.

Adult↗
PubMed1999

The cutaneous lymphocyte antigen is an essential component of the L-selectin ligand induced on human vascular endothelial cells.

L-selectin mediates leukocyte rolling on vascular endothelium during inflammation. Although vascular endothelium can be activated with inflammatory cytokines to express functional L-selectin ligands, these ligands have not been well characterized. In this study, fucosyltransferase VII cDNA (Fuc-TVII) transfection of the EA.hy926 human vascular endothelial cell line (926-FtVII) induced functional L-selectin ligand expression and expression of sialyl Lewisx (sLex), as defined by HECA-452 (cutaneous lymphocyte antigen; CLA) and CSLEX-1 mAbs. Cytokine activation of human umbilical vein endothelial cells (HUVEC) also induced functional L-selectin ligand expression, with increased CLA expression and Fuc-TVII transcription. The majority of L-selectin-dependent lymphocyte attachment to activated HUVEC and 926-FtVII cells was blocked specifically by treating the endothelial cells with the HECA-452 mAb, but not the CSLEX-1 mAb. CLA-bearing ligands on vascular endothelium also required sulfation and appropriate molecular scaffolds for functional activity, but were distinct from the L-selectin ligands previously identified by the MECA-79 mAb. These findings demonstrate that the HECA-452- defined antigen, CLA, is an essential carbohydrate component of vascular L-selectin ligands.

Antibodies, Monoclonal↗
PubMed1999

Use of poly(tetrafluoroethylene)s as a sample support for the MALDI-TOF analysis of DNA and proteins.

Matrix-assisted laser desorption/ionization mass spectrometry of DNA and proteins, directly deposited on the poly(tetrafluoroethylene) (Teflon) surface, is demonstrated. For DNA analysis, this technique apparently produces a more homogeneous coverage of the matrix/DNA over the sample surface. Moreover, it enhances the sensitivity and salt tolerance. As described here, this technique can also achieve an excellent mass resolution, similar to that observed using a metal probe for DNA up to 62mer. We also examined the use of Teflon as a sample support for protein analysis since Teflon has been used as a transfer membrane. Less than 25 fmol of myoglobin has been detected with this technique. In addition, effective MALDI-TOF analysis of salt-contaminated protein samples can also be accomplished by loading the protein sample onto Teflon, followed by steps of washing away salts, adding the matrix, and desorbing sample directly from Teflon.

DNA↗
PubMed1999

Determination of platinum in rat dorsal root ganglion using ICP-MS.

This study evaluated the performance of inductively coupled plasma mass spectrometry for the determination of platinum (Pt) in rat dorsal root ganglion. The method detection limit was found to be 0.008 ng/mL of Pt, which corresponds to 4 pg of Pt per milligram of ganglia. The standard deviations in the tissue matrix were 5.7% or better and minimum matrix effect was observed. Compared to indium, the use of iridium or a combination of iridium and bismuth as internal standard(s) provided more accurate measurement. The Pt in the tissue digestate was stable for a minimum of 46 d at levels above 0.05 ng/mL. Flow injection analysis using undiluted digestates resulted in approximately 20% signal enhancement. Internal standard correction was necessary to obtain accurate results. The method was used in initial studies in which rats were dosed with cisplatin and has shown that Pt accumulates and persists in dorsal rat ganglion following treatment.

Animals↗
PubMed1999

Acetylcholine-induced relaxation of peripheral arteries isolated from mice lacking endothelial nitric oxide synthase.

1. Acetycholine-mediated relaxations in phenylephrine-contracted aortas, femoral and mesenteric resistance arteries were studied in vessels from endothelial nitric oxide synthase knock-out (eNOS -/-) and the corresponding wild-type strain (eNOS +/+) C57BL6/SV19 mice. 2. Aortas from eNOS (+/+) mice relaxed to acetylcholine in an endothelium-dependent NG-nitro-L-arginine (L-NOARG) sensitive manner. Aortas from eNOS (-/-) mice did not relax to acetylcholine but demonstrated enhanced sensitivity to both authentic NO and sodium nitroprusside. 3. Relaxation to acetylcholine in femoral arteries was partially inhibited by L-NOARG in vessels from eNOS (+/+) mice, but relaxation in eNOS (-/-) mice was insensitive to a combination of L-NOARG and indomethacin and the guanylyl cyclase inhibitor 1H-[1,2, 4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). The L-NOARG/ODQ/indomethacin-insensitive relaxation to acetylcholine in femoral arteries was inhibited in the presence of elevated (30 mM) extracellular KCl. 4. In mesenteric resistance vessels from eNOS (+/+) mice, the acetylcholine-mediated relaxation response was completely inhibited by a combination of indomethacin and L-NOARG or by 30 mM KCl alone. In contrast, in mesenteric arteries from eNOS (-/-) mice, the acetylcholine-relaxation response was insensitive to a combination of L-NOARG and indomethacin, but was inhibited in the presence of 30 mM KCl. 5. These data indicate arteries from eNOS (-/-) mice demonstrate a supersensitivity to exogenous NO, and that acetylcholine-induced vasorelaxation of femoral and mesenteric vessels from eNOS (-/-) mice is mediated by an endothelium-derived factor that has properties of an EDHF but is neither NO nor prostacyclin. Furthermore, in mesenteric vessels, there is an upregulation of the role of EDHF in the absence of NO.

Acetylcholine↗
PubMed1999

Molecular cloning and expression of Galbeta1,3GalNAc alpha2, 3-sialyltransferase from human fetal liver.

Based on the sequences of the highly conserved segments in the previously cloned sialyltransferases, a cDNA encoding Galbeta1, 3GalNAc alpha2,3-sialyltransferase (SIATFL) has been isolated from human fetal liver. Expression analysis of the gene has been performed with various carcinoma cell lines, fetal tissues, fetal and adult liver and both hepatoma and the surrounding tissue from the same liver. The SIATFL gene was expressed poorly in fetal liver and in adult liver, slightly in hepatoma and highly in the surrounding tissue of hepatoma. The cDNA encoding the putative active domain was expressed in COS-1, Escherichia coli, and Pichia pastoris. The recombinant protein expressed in COS-1 could catalyse the transfer of NeuAc from CMP-NeuAc to asialo-fetuin. No enzyme activity was detected with a 32-kDa protein in E. coli and both 32-kDa and 41-kDa proteins in P. pastoris. These results suggested that correct glycosylation of the enzyme might play a key role in its folding that may be directly related to the enzymatic activity.

Amino Acid Sequence↗