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Biomedical subjects

D Zhu

Publications and source records attributed to D Zhu.

At least 73 records · Page 4Linked to original sources
PubMed2001

[Use of microsatellites in zygosity diagnosis of twins].

OBJECTIVE: To diagnose zygosity of twins by microsatellite polymorphism. METHODS: One hundred and eighty-four samples, including 69 pairs of twins with the same gender and 6 pairs of twins with different gender were recruited. Seventeen sib pairs were also collected for controls. Nine highly polymorphic microsatellite loci were amplified by polymerase chain reaction (PCR) using fluorescence-labeled primers and the products were sized by automated fragment analysis after electrophoresis and laser detection. Zygosity was diagnosed by comparing the concordance of the genotype of the 9 markers. RESULTS: Sixty-three pairs of monozygotic (MZ) and 12 pairs of dizygotic (DZ) twins were assigned their zygosity by comparison of polymorphism of 9 microsatellite loci. Within each of the 63 monozygotic (MZ) pairs there was complete concordance. However, within each of the 12 dizygotic pairs and other 17 sib pairs, discordant loci were found. With five or six markers, the probability that any twin pair was MZ if all markers were concordant was 99% or 99.6%, respectively. With all the nine markers, the probability that any twin pair was MZ if all markers were concordant was 99.95%. CONCLUSION: The technology of gene scan and genotyping provides a rapid and reliable approach to zygosity detection.

DNA↗
PubMed2001

[Computing ECG based on action potential of single cardiac cell].

This paper introduces an ECG computing algorithm that computes ECG based on the action potential of single cardiac cell. Taking solid angle analysis as tool, this algorithm analyzes the field potential of a cardiac cell that connects and communicates with neighboring cells. This algorithm has been implemented in our electrophysiological model CardioAuto, which was built with extended Cellular 3.0-a cellular automata system. Algorithm and simulation results reveal that it is the transmembrane potential slope among cell group that contributes to ECG waveform generation and determines the waveform deflection. To a specific lead location, whenever cell group has a transmembrane potential slope that proximal end is higher than distal end, a downward ECG deflection is generated. Whenever cell group has a reverse transmembrane potential slope, an upward ECG deflection is generated. Whenever there is no transmembrane potential slope, ECG keeps on baseline. According to our algorithm, the significance of normal and many abnormal ECG waveforms can be analyzed and interpreted at cellular level.

Action Potentials↗
PubMed2001

Dynamic changes of interleukin-1, interleukin-6 and tumor necrosis factor in intermingled skin graft in burned rats.

OBJECTIVE: To compare the dynamic changes of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in intermingled skin graft with those in other types of skin grafts in rats. METHODS: A 10%-15% third-degree burn was created in 180 Sprague-Dawley (SD) rats. After removing the scar, skin grafts were performed on the open wounds immediately with autoskin (aus, n=54), alloskin (als, n=54) and intermingled skin (n=36). That is to say, in the intermingled skin graft, a big piece of alloskin (mals) was grafted first, and 3 days later, small pieces of autoskin (maus) wer e embedded in the alloskin. The rest 36 rats were taken as the controls. And the biological activities of IL-1, IL-6 and TNF in graft sheets in each group were detected after skin graft. RESULTS: The levels of IL-1, IL-6 and TNF in the aus group decreased steadily after their initial elevations, whereas in the als group they increased significantly and kept on the peak level in the later phases. In the in termingled group, there appeared a lowest IL-1 level in the mals and a highest one in the maus simultaneously at 7 (4) days (The number out of parenthesis is t he days after transplanting with alloskin sheets, and the number in parenthesis is the days after embedding autoskin sheets in the intermingled skin graft. Similarly hereinafter.) after skin graft (P<0.01), and the high level in the maus abruptly decreased at 14 (11) days after skin graft. At exactly the same phase on day 7 (4), a prominent peaked IL-6 in the mals occurred. In the later phases, the levels of TNF remained relatively low both in the m als and in the maus. From day 7 (4) on, each cytokine fluctuation in the mals synchronized with that in the maus. The longer the post transplantation period lasted, the more the positive cytokine correlated between the mals and the maus. CONCLUSIONS: The low levels of IL-1 and TNF may be important f actors to lighten the intensity of local rejection in the intermingled skin graft. The temporarily peaked IL-6 is both an inducer which induces the production of local IL-1 receptor antagonists and soluble TNF receptors and a signal which indicates a local enhancement of Th(2) cells. The mild rejection process and th e synchronized cytokine level during the later phases suggest a possible chimerism between the mals and the maus.

Animals↗
PubMed2001

[Study on the association of pathologic myopia with HLA-DQB1 gene].

OBJECTIVE: To investigate the association of pathologic myopia (PM) with HLA-DQB1 alleles in order to study the pathogenesis of PM. METHODS: The genome DNA of 66 patients with PM was extracted from the blood. The second exon of the HLA-DQB1 gene was amplified by polymerase chain reaction (PCR), and individual PCR products were digested by allele specific restriction enzymes of Hae III, BssH II, Apa I, BsaH I, Hae II, Hpa II, Rsa I, Bsp 1286 I for typing. Genotype was determined by restriction fragment length polymorphism (RFLP) pattern. The frequency of 16 alleles of HLA-DQB1 was detected and compared with that of the healthy control. RESULTS: The frequencies of HLA-DQB1 * 0301 and * 0303 were significantly higher in the patients with PM (P < 0.0001), while that of HLA-DQB1 * 0601 and * 0602 were significantly lower (P < 0.0001) than that of the control group. CONCLUSION: HLA-DQB1 * 0301, * 0303 alleles are susceptible alleles, and possibly they are the pathogenic genes, * 0601, * 0602 are resistant alleles, and may be they possess the protective property.

Adolescent↗
PubMed2001

[General situations of medical rescue at Shanghai public concession in the 30s of 20th century].

In the 30s of 20th century, Shanghai public concession is the largest concession of old China. Health Department of Work Bureau and Fire Department administrated the rescue works in concession. The affiliated first -- aid sections and hospitals were responsible for concrete rescue works of patients. The health workers were hardworking for the health, body and mind, of all kinds of people, inside and outside, and achieved clear results.

China↗
PubMed2001

[Climbing-upward inhibition of Oncomelania hupensis by niclosamide combination].

OBJECTIVE: To develop a combination of molluscicide/insecticide with a good molluscicidal effect, especially an inhibitory effect on climbing-upward of Oncomelania hupensis. METHODS: Experiments on molluscicidal and snail-climbing inhibition effect of the combination of niclosamide and shachongding [(dimethylamine) trithacyclohexane hydrochloride] were conducted by immersion and spraying in laboratory. RESULTS: The combination of niclosamide (0.2 mg/L) and shachongding (0.1 mg/L) showed an inhibition of 92.67% of snails to climb up. There was no significant difference in molluscicidal effect between the combination (LC90 0.198 mg/L) and niclosamide alone (LC90 0.207 mg/L). CONCLUSION: The combination showed an effective inhibition on the climbing-upward of snails in water so as to improve the molluscicidal effect and reduce the cost of mollusciciding.

Animals↗
PubMed2000

Mapping of X chromosome inversion breakpoints [inv(X)(q11q28)] associated with FG syndrome: a second FG locus [FGS2]?

FG syndrome is an X-linked condition comprising mental retardation, congenital hypotonia, macrocephaly, distinctive facial changes, and constipation or anal malformations. In a linkage analysis, we mapped a major FG syndrome locus [FGS1] to Xq13, between loci DXS135 and DXS1066. The same data, however, clearly demonstrated genetic heterogeneity. Recently, we studied a French family in which an inversion [inv(X)(q12q28)] segregates with clinical symptoms of FG syndrome. This suggests that one of the breakpoints corresponds to a second FG syndrome locus [FGS2]. We report the results of fluorescence in situ hybridization analysis performed in this family using YACs and cosmids encompassing the Xq11q12 and Xq28 regions. Two YACs, one positive for the DXS1 locus at Xq11.2 and one positive for the color vision pigment genes and G6PD loci at Xq28, were found to cross the breakpoints, respectively. We postulate that a gene might be disrupted by one of the breakpoints.

Abnormalities, Multiple↗
PubMed2000

Effect of suppression of TGF-beta1 expression on cell-cycle and gene expression of beta-1,4-galactosyltransferase 1 in human hepatocarcinoma cells.

beta-1,4-galactosyltransferase 1 (beta1,4-GT 1) is localized both in the Golgi complex where it catalyzes the transfer of galactose from UDP-galactose to terminal N-acetylglucosamine forming Galbeta1 --> 4GlcNAc structure, and on the cell surface where it serves as an adhesion molecule. It has previously been reported that the expression of beta1,4-GT 1 was cell-cycle-specific, regulated by cell growth. Transforming growth factor-beta1 (TGF-beta1) could regulate cell G1/S phase transition and modulate cell growth in many types of cells. In this study, we introduced the antisense-TGF-beta1 into SMMC-7721 cell, a human hepatocarcinoma cell line, for blocking its intrinsic TGF-beta1 expression, and changing its cell-cycle, and then analyzed the gene expression of beta1,4-GT 1 together with the beta1,4-GT activity. The result showed that the antisense-TGF-beta1 transfected SMMC-7721 cells (AST/7721) were growth enhanced, with more cells in S phase and less cells in G2/M phase compared with the mock transfected cells (pcDNA3/7721). At the same time, it was found that the gene expression of beta1,4-GT 1 in AST/7721 was decreased to one fifth that of pcDNA3/7721, and the cell surface beta1,4-GT activity was reduced to one fifth of the control, while the total activity of beta1,4-GT was decreased to one half that of the control. The results indicate that suppression of TGF-beta1 expression resulted in change of cell-cycle together with the decreased gene expression of beta1,4-GT 1 and beta1,4-GT activity in human hepatocarcinoma cells.

Carcinoma, Hepatocellular↗
PubMed2000

Effective mucosal immunization against respiratory syncytial virus using purified F protein and a genetically detoxified cholera holotoxin, CT-E29H.

We exploited the powerful adjuvant properties of cholera holotoxin (CT) to create a mucosally administered subunit vaccine against respiratory syncytial virus (RSV). A genetically detoxified mutant CT with an E to H substitution at amino acid 29 of the CT-A1 subunit (CT-E29H) was compared to wild type CT for toxicity and potential use as an intranasal (IN) adjuvant for the natural fusion (F) protein of RSV. When compared to CT the results demonstrated that: (1) CT-E29H binding to GM1 ganglioside was equivalent, (2) ADP-ribosylation of agmatine was 11.7%, and (3) toxicity was attenuated in both Y-1 adrenal (1.2%) and patent mouse gut weight assays. IN vaccination with F protein formulated with CT-E29H induced serum anti-CT and anti-F protein antibodies that were comparable to those obtained after vaccination with equivalent doses of CT. Vaccinations containing CT-E29H at doses of 0.1 microg were statistically equivalent to 1.0 microg in enhancing responses to F protein. Antigen-specific mucosal IgA and anti-RSV neutralizing antibodies were detected in nasal washes and sera, respectively, of mice that had received F protein and 0.1 or 1.0 microg of CT-E29H. Anti-F protein IgA was not detected in the nasal washes from mice IN vaccinated with 0.01 microg CT-E29H or IM with F protein adsorbed to AlOH adjuvant. In addition, the formulation of purified F protein and CT-E29H (0.1 and 1.0 microg) facilitated protection of both mouse lung and nose from live RSV challenge. Collectively, the data have important implications for vaccine strategies that use genetically detoxified mutant cholera holotoxins for the mucosal delivery of highly purified RSV antigens.

Animals↗
PubMed2000

Characterization of rat CD14 promoter and its regulation by transcription factors AP1 and Sp family proteins in hepatocytes.

CD14, a 55kDa glycoprotein, serves as a lipopolysaccharide (LPS) recognition molecule. CD14 is a monocyte differentiation antigen expressed by myeloid-derived cells, or other cells such as hepatocytes, as either a membrane-bound protein or a soluble serum protein. Increasing evidence indicates that soluble CD14 in plasma is an acute-phase protein derived, among other sources, from liver cells. Although information is available on the cellular expression of CD14, little is known about the cis- and trans-acting factors that regulate basal CD14 transcription in liver cells. We show here that liver cells have a relatively high basal CD14 transcription rate as determined by nuclear run-on assay. We cloned and sequenced an 883bp 5'-flanking region of the rat CD14 gene and demonstrated functional promoter activity in liver cells. Sequence analysis revealed that, like in the human and mouse CD14 genes, multiple Sp1 and AP1 binding elements exist in rat CD14. Site-directed mutagenesis and transient transfection assays demonstrated that an Sp1 element located at -836 and an AP1 element located at -270 are required for basal promoter activity in liver cells. Electrophoretic mobility shift assays indicate that both Sp1 and Sp3 nuclear factors interact with the -836 Sp1 element, while the AP1-related proteins Fra-2 and JunD bind to the AP1 motif. These data provide novel insights into the regulation of basal CD14 expression in liver cells.

3T3 Cells↗
PubMed2000

Identification of selective estrogen receptor modulators by their gene expression fingerprints.

Clinical studies have shown that estrogen replacement therapy (ERT) reduces the incidence and severity of osteoporosis and cardiovascular disease in postmenopausal women. However, long term estrogen treatment also increases the risk of endometrial and breast cancer. The selective estrogen receptor (ER) modulators (SERMs) tamoxifen and raloxifene, cause antagonistic and agonistic responses when bound to the ER. Their predominantly antagonistic actions in the mammary gland form the rationale for their therapeutic utility in estrogen-responsive breast cancer, while their agonistic estrogen-like effects in bone and the cardiovascular system make them candidates for ERT regimens. Of these two SERMs, raloxifene is preferred because it has markedly less uterine-stimulatory activity than either estrogen or tamoxifen. To identify additional SERMs, a method to classify compounds based on differential gene expression modulation was developed. By analysis of 24 different combinations of genes and cells, a selected set of assays that permitted discrimination between estrogen, tamoxifen, raloxifene, and the pure ER antagonist ICI164384 was generated. This assay panel was employed to measure the activity of 38 compounds, and the gene expression fingerprints (GEFs) obtained for each compound were used to classify all compounds into eight groups. The compound's GEF predicted its uterine-stimulatory activity. One group of compounds was evaluated for activity in attenuating bone loss in ovariectomized rats. Most compounds with similar GEFs had similar in vivo activities, thereby suggesting that GEF-based screens could be useful in predicting a compound's in vivo pharmacological profile.

Animals↗
PubMed2000

2,3,4,5-Tetrakis[(2-hydroxyethyl)thio]tetrathiafulvalene tetrafluoroborate.

The title complex, C(14)H(20)O(4)S(8)(+)(.)BF(4)(-), is a charge-transfer complex with typical charges for the donor and anion of +1 and -1, respectively. Two centrosymmetrically related donors form a face-to-face pi-dimer with a strong intermolecular S.S interaction. These pi-dimers stack along the a axis to form a donor column. The structure is extensively hydrogen bonded.

Journal Article↗
PubMed2000

Interaction between CD44 and the repeat domain of ankyrin promotes hyaluronic acid-mediated ovarian tumor cell migration.

The adhesion molecule, CD44, interacts with ankyrin within its cytoplasmic domain and binds to hyaluronic acid (HA) at its extracellular domain. In this study, we focused on the functional domain in ankyrin (in particular, the ankyrin repeat domain [ARD]) responsible for CD44 binding and its role in regulating HA-mediated ovarian tumor cell function. Using recombinant fragments of ankyrin (e.g., ARD and subdomain 1 [S1, aa1-aa217], subdomain 2 [S2, aa218-aa381], subdomain 3 [S3, aa382-aa612], and subdomain 4 [S4, aa613-aa834]) and in vitro binding assays, we determined that the S2 but not S1, S3, or S4 of ARD is the primary ankyrin binding region for CD44. Microinjection of antiglutathione S-transferase (GST)-tagged S2 or GST-tagged ARD fusion protein into CD44-positive ovarian tumor cells (e.g., SKOV3 cell line) promotes ankyrin association with CD44 in plaque-like structures and membrane projections. Additionally, we demonstrated that transfection of SKOV3 cells with S2cDNA or ARD cDNA results in an upregulation of HA-mediated tumor cell migration. Taken together, we believe that the S2 of the ARD plays a pivotal role in the direct binding to CD44 and promotes the cytoskeleton activation required for HA-mediated function such as ovarian tumor cell migration.

Amino Acid Sequence↗
PubMed2000

The role of TGF-beta 1 in mice hepatic fibrosis by Schistosomiasis Japonica.

To investigate the role of transforming growth factor-beta 1 (TGF-beta 1) in mice with hepatic fibrosis caused by Schistosomiasis Japonica, ELISA, VG staining and multimedia color hieroglyph quantitative analysis were used to study the change of the serum TGF-beta 1, liver collagen fiber and reticular fiber in mice. The level of serum TGF-beta 1 in experimental group was significantly higher than that in control group (P < 0.01 or P < 0.05) 8, 10, 12 weeks after infected by schistosomiasis. After infection, the level of liver collagen fiber and reticular fiber, and that of TGF-beta 1 increased over time (P < 0.01 or P < 0.05). In mice infected by Schistosomiasis Japonica, the level of TGF-beta 1 increased with prolongation of infection time, and with the increase of liver collagen fiber and reticular fiber. TGF beta 1 plays an important role of immunomodulation in hepatic fibrosis formation caused by Schistosomiasis Japonica.

Animals↗
PubMed2000

Ultracentrifuge and circular dichroism studies of folding equilibria in a retro GCN4-like leucine zipper.

Equilibrium ultracentrifuge and circular dichroism (CD) studies of a retropeptide of a GCN4-like leucine zipper in neutral saline buffer are reported as functions of temperature. Ultracentrifuge results indicate the presence of three oligomeric species: monomer, dimer, and tetramer, in quantifiable amounts, and the data provide values for the standard DeltaG, DeltaH, and DeltaS for interconversion. CD at 222 nm displays the strong concentration dependence characteristic of dissociative unfolding, but also shows a helicity far below that of the parent propeptide. Remarkably enough, the CD at 222 nm shows an extremum in the region between 0 and 20 degrees C. At higher T, the usual cooperative unfolding is observed. Comparable data are presented for a mutant retropeptide, in which a single asparagine residue is restored to the characteristic heptad position it occupies in the propeptide. The mutant shows marked differences from its unmutated relative in both thermodynamic properties and CD, although the oligomeric ensemble also comprises monomers, dimers, and tetramers. The mutant is closer in helicity to the parent propeptide but is less stable. These findings do not support either of the extant views on retropeptides. The behavior seen is consistent neither with the view that retropeptides should have the same structure as propeptides nor with the view that they should have the same structure but opposite chirality. The simultaneous availability of oligomeric population data and CD allows the latter to be dissected into individual contributions from monomers, dimers, and tetramers. This dissection yields explanations for the observed extrema in curves of CD (222 nm) versus T and reveals that the dimer population in both retropeptides undergoes "cold denaturation."

Amino Acid Sequence↗
PubMed2000

Genetic basis of total colourblindness among the Pingelapese islanders.

Complete achromatopsia is a rare, autosomal recessive disorder characterized by photophobia, low visual acuity, nystagmus and a total inability to distinguish colours. In this disease, cone photoreceptors, the retinal sensory neurons mediating colour vision, seem viable but fail to generate an electrical response to light. Achromatopsia, or rod monochromatism, was first mapped to 2p11-2q12 (MIM 216900; ref. 3), where it is associated with missense mutations in CNGA3 (ref. 4). CNGA3 encodes the alpha-subunit of the cone cyclic nucleotide-gated cation channel, which generates the light-evoked electrical responses of cone photoreceptors. A second locus at 8q21-q22 has been identified among the Pingelapese islanders of Micronesia, who have a high incidence of recessive achromatopsia (MIM 262300). Here we narrow the achromatopsia locus to 1.4 cM and show that Pingelapese achromatopsia segregates with a missense mutation at a highly conserved site in CNGB3, a new gene that encodes the beta-subunit of the cone cyclic nucleotide-gated cation channel. Two independent frameshift deletions establish that achromatopsia is the null phenotype of CNGB3. Combined with earlier findings, our results demonstrate that both alpha- and beta-subunits of the cGMP-gated channel are essential for phototransduction in all three classes of cones.

Adolescent↗