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Biomedical subjects

C Wu

Publications and source records attributed to C Wu.

At least 127 records · Page 7Linked to original sources
PubMed2001

The novel gene locus for agenesis of permanent teeth (He-Zhao deficiency) maps to chromosome 10q11.2.

He-Zhao deficiency has been recently characterized with a distinct form of agenesis of permanent teeth that is different from other previously reported disorders of tooth agenesis. This inherited abnormality suggests that some gene(s) associated with the development of permanent teeth may mutate. In this study, we map the gene locus to chromosome 10q11.2. The DNA pooling method combined with two-point and multi-point linkage analysis has been successfully applied. The maximum LOD (Zmax) scores for two-point and multi-point analyses are 13.29 (on marker D10S196) at recombination fraction (theta) = 0 and 18.09 (between markers D10S1772 and D10S1766), respectively. Haplotype analysis confined the locus within an interval of 5.5 cM flanked by markers D10S604 and D10S568. This study has demonstrated a novel gene locus responsible for He-Zhao deficiency and provides a good likelihood for the discovery of one of the genes determining permanent tooth formation and development.

Alleles↗
PubMed2001

TBC3711, an ET(A) receptor antagonist, reduces neonatal hypoxia-induced pulmonary hypertension in piglets.

The pulmonary vasculature of newborns with persistent pulmonary hypertension is characterized by active vasoconstriction and vascular remodeling. It has been suggested that endothelin-1 (ET-1), a potent vasoconstrictor and growth promoter, may be involved in the pathogenesis of persistent pulmonary hypertension of the newborn. To determine whether treatment with an ET(A) receptor antagonist can reverse pulmonary hypertension in the neonate, 1-d-old piglets were exposed to hypoxia for 3 d to induce pulmonary hypertension and then treated for the remainder of the 14 d with an orally active, nonpeptidic ET(A) antagonist (TBC3711, 22 mg x kg(-1) x d(-1)). At the end of the exposure, Hb, pulmonary artery pressure, right ventricle to left ventricle plus septum weight ratio, percentage wall thickness, ET-1 circulating levels, perfusion pressure, and dilator response to the nitric oxide (NO) donor, SIN-1 (3-morpholinosydnonimine-N-ethylcarbamide) in isolated perfused lungs were determined. Exhaled NO and hemodynamic variables were also examined in an intact anesthetized animal preparation that had undergone the same treatment. By 3 d of exposure to hypoxia, piglets had already developed significant pulmonary hypertension as estimated by their pulmonary artery pressure (24.0 +/- 1.3 mm Hg versus 14.2 +/- 3.4 mm Hg) and percentage wall thickness (26.6 +/- 5.9% versus 18.7 +/- 2.4% for vessels 0-30 microm). Whereas further exposure to hypoxia for 14 d did not enhance the increase in pulmonary artery pressure and percentage wall thickness, it did augment the right ventricle to left ventricle plus septum weight ratio (0.71 +/- 0.09 versus 0.35 +/- 0.01). ET-1 circulating levels were increased only when exposure to hypoxia was prolonged to 14 d (5.1 +/- 2.4 pg/mL versus 1.0 +/- 0.4 pg/mL). Treatment with TBC3711 from d 3 to d 14, once pulmonary hypertensive changes were established and while hypoxic exposure persisted, caused significant reduction in the right ventricle to left ventricle plus septum weight ratio (0.60 +/- 0.06), pulmonary artery pressure (20.0 +/- 4.8 mm Hg), and percentage wall thickness (18.5 +/- 3.3%) and restored the dilator response to the NO donor SIN-1. Prolonged hypoxia markedly reduced exhaled NO concentrations (0.3 +/- 0.6 ppb), although treatment of hypoxic animals with TBC3711 restored the concentration of exhaled NO (4.4 +/- 2.8 ppb) to the level of normoxic controls (4.9 +/- 3.0 ppb). Lastly, treatment with TBC3711 increased ET-1 circulating levels in both the normoxic (5.4 +/- 2.8 pg/mL) and hypoxic (13.0 +/- 6.3 pg/mL) groups. In conclusion, the specific ET(A) receptor antagonist, TBC3711, can significantly ameliorate the morphologic changes encountered in hypoxia-induced pulmonary hypertension in the newborn piglet and may improve the dilator response to NO.

Animals↗
PubMed2001

ILK interactions.

Explore the source record for details and available documents.

Cell Adhesion↗
PubMed2001

Derivative matrix isopotential synchronous fluorescence spectroscopy for the direct determination of 1-hydroxypyrene as a urinary biomarker of exposure to polycyclic aromatic hydrocarbons.

Urinary 1-hydroxypyrene is a biomarker in the measurement of human exposure to polycyclic aromatic hydrocarbons. A rapid and simple derivative isopotential synchronous fluorescence method was developed for the direct determination of 1-hydroxypyrene in urine. A length of iso-intensity route was scanned on the three-dimensional fluorescence spectrum of urine and this result was combined with that from derivative technique. Thus the strong background signals of urine were removed and the 1-hydroxypyrene can be determined directly in urine without tedious pre-separation. The derivative isopotential synchronous fluorescence spectrum was directly obtained from a single scan on a spectrofluorometer, which further simplified isopotential synchronous fluorescence technique. The recoveries of 93% to 115% were obtained for 1-hydroxypyrene added to urine.

Biomarkers↗
PubMed2001

Reactivity of serum samples of dogs and horses tested by use of class-specific recombinant-based enzyme-linked immunosorbent assays for detection of granulocytic ehrlichiosis.

OBJECTIVE: To test serum samples of dogs and horses by use of class-specific recombinant-based ELISA for establishing a diagnosis of granulocytic ehrlichiosis attributable to infection with organisms from the Ehrlichia phagocytophila genogroup. SAMPLE POPULATION: Serum samples from 43 client-owned dogs and 131 horses (81 with signs of acute illness and 50 without signs of disease). PROCEDURE: Serum samples were analyzed, using ELISA with a recombinant 44-kd protein antigen for IgM and IgG antibodies to the human granulocytic ehrlichiosis (HGE) agent (NCH-1 strain). Western blot analyses, using infected human promyelocytic leukemia cells, were conducted on 38 serum samples of horses and 11 serum samples of dogs to verify reactivity to the 44-kd peptide. RESULTS: IgM or IgG antibodies to the HGE agent were detected in 5 to 28% of dog serum samples and 5 to 37% of horse serum samples. Thirty-five of 38 (92%) horse serum samples had corresponding results on both tests (2 positive results for 26 samples and 2 negative results for 9 samples), using an ELISA for IgG antibodies or immunoblotting for total immunoglobulins. All 11 serum samples of dogs had positive results for both methods. CONCLUSION AND CLINICAL RELEVANCE: These ELISA with recombinant 44-kd antigen are suitable for detecting IgM or IgG antibodies to the HGE agent in serum samples of dogs and horses. Positive results for serum samples of horses from Connecticut, New York, Virginia, and Georgia indicate that the HGE agent is widely distributed in tick-infested areas of the eastern United States.

Animals↗
PubMed2001

Evaluation of a polyvalent enzyme-linked immunosorbent assay incorporating a recombinant p44 antigen for diagnosis of granulocytic ehrlichiosis in dogs and horses.

OBJECTIVE: To develop and evaluate a polyvalent ELISA incorporating a highly specific recombinant antigen (p44) for diagnosis of granulocytic ehrlichiosis in dogs and horses. ANIMALS: 32 dogs and 43 horses. PROCEDURE: Results of the ELISA were compared with results of indirect fluorescent antibody (IFA) staining and western immunoblotting incorporating whole-cell antigen. RESULTS: For the canine and equine samples, percentages of samples with positive IFA staining, western immunoblotting, and ELISA results were similar. For 29 (91 %) canine samples and 30 (70%) equine samples, results of IFA staining, western immunoblotting, and the ELISA were in complete agreement. Results of the ELISA for 3 canine serum samples known to contain antibodies to Ehrlichia canis and 12 equine serum samples known to contain antibodies to E risticii were negative. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the present study suggest that a polyvalent ELISA incorporating a recombinant p44 antigen is suitable for detecting antibodies to E equi in dogs and horses.

Animals↗
PubMed2001

[Lipopolysaccharide upregulates expression of CD14 gene and CD14 proteins of hepatocytes in rats].

OBJECTIVE: To observe the expression of CD14 mRNA and its protein in rat hepatocytes during endotoxemia. METHODS: The acute endotoxemia model of wistar rats was established by injection of a dose of LPS (5mg/kg, Escherichia coli O111:B4) via the tail vein, then the rats were sacrificed at 3, 6, 12, and 24 hour, respectively. Hepatocytes were isolated from normal and LPS-injected rats by in situ collagenase perfusion technique. Hepatocytes and hepatic tissue were collected to measure the expression of CD14 mRNA and CD14 protein by reverse transcriptase-polymerase chain reaction (RT-PCR) or Western blot analysis. The binding of fluorescein isothiocyanate (FITC)-CD14 polyclone antibody to isolated hepatocytes was also assessed by flow cytometric analysis (FCM). RESULTS: In the rats with endotoxemia, the expression of CD14 mRNA and CD14 protein in hepatic tissue and isolated hepatocytes were stronger at 6, 12 and 24 hour than that in control rats (P<0.01). FCM showed that positive cell numbers of FITC-CD14 in the rats with endotoxemia increased when compared with normal control group (P<0.01). CONCLUSIONS: LPS can markedly upregulate the expression of CD14 mRNA and CD14 proteins in hepatic tissue and isolated hepatocytes.

Animals↗
PubMed2001

[An epidemiological study on the factors influencing length of hospitalization for inpatients of burns].

OBJECTIVE: To provide evidence for intervention on secondary prevention of burns through studying the factors influencing the length of hospitalization on inpatients of burns. METHODS: Seven hundred and ninety burnt patients with cluster sampling, combined analyzing with Cox regression and factor analysis. RESULTS: The influential factors on the length of hospitalization in inpatients with burns included a) how did the patients come to the hospital (X3), b) total body surface area involved (X4), c) depth of burns (X5), and d) the time before hospitalization after burnt (X6). The Cox proportional hazard model used was h(t)/h0(t) = e(-0.193 3F1 -0.617 6F2 -0.118 0F3), and the conversion model between factors Fi and original variates were F1 = -0.132X3 - 0.009X4 + 0.655X5 + 0.583X6, F2 = 0.019X3 + 0.875X4 + 0.257X5 - 0.294X6, F3 = 1.010X3 + 0.025X4 - 0.176X5 + 0.030X6. Data showed that the burnt patients had longer hospitalization time when the burns were deep, larger body surface area involved, and with longer delay before getting to the hospitals, where as the patients got cured faster when taken to the hospital by ambulances. CONCLUSION: One of the major prognostic factors of burns was to treat the patients in time. Secondary prevention of burns must be reinforced.

Adolescent↗
PubMed2001

[Characteristics of nitrobenzene containing wastewater catalytic oxidation degradation by Fenton reagent].

Through the alteration of the concentration of catalyst and oxidant, the rulers and dynamics of nitrobenzene oxidized by Fenton reagent in different concentrations were studied. The correlativity of the reaction time and relatively remain nitrobenzene was analyzed by the unitary linear regress equation. The result of the analysis proves that the coefficient was over the critical constant. The oxidation of nitrobenzene by Fenton reagent was in conformity with first-order dynamics model and the reaction rate constant was got at the same time. The idea, using the complex of Fe as the catalyst replacing Fe2+ in the Fenton Reaction, not only got a higher reaction velocity and efficiency, but also had a distinct exclusive to the degradation of nitrobenzene. The remove velocity of nitrobenzene was improved from 17.48 mg/(L.min) to 71.22 mg/(L.min), the remove rate in 5 minutes was from 9.74% to 91.79%. The nonhomogeneous catalyst made by the artificial zeolite with Fe-complex adsorbed had the same catalyzing behavior. In addition, ultraviolet radiation can also improves the Fenton reaction to some degree. These research works could demonstrate the good application potentiality of Fenton reagent in treating wastewater.

Catalysis↗
PubMed2001

[Clinical study of P-gp, and bcl-2 protein expression in non-Hodgkin's lymphomas patients].

OBJECTIVE: To investigate the relationship between the expression of P-gp, P26-bcl-2 and the prognosis in intermediate and high grade non-Hodgkin's lymphomas (NHL). METHODS: Sixty cases of intermediate and high grade NHL were retrospectively reviewed using immunohistochemical method. All patients were received CHOP chemotherapy over 4 courses. RESULTS: P-gp was identified in 15 and P26-bcl-2 in 25 cases. The 3-year survival rates for patients with P26-bcl-2 (+) and P26-bcl-2 (-) were 37.64% and 76.80%, respectively (P < 0.005), and for patients with both positive P-gp and P26-bcl-2 and both negative were 15.38% and 48.48%, respectively (P = 0.038). CONCLUSIONS: There is direct relationship between the P-gp, P26-bcl-2 protein expression and the prognosis in intermediate and high grade non-Hodgkin's lymphoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

[Study of Raman-PL spectra for GaAs layer on Si substrate in hot wall epitaxy].

The quality of GaAs layer on the Si substrate under different growth conditions with HWE technology was studied by Raman and PL spectra. The results show that the ratio of peak value to area for the TO peak at 265 cm-1 increased gradually with the improvement of the GaAs crystallinity quality for the GaAs layer at 300 K. The FWHM of Raman spectra of TO peak at 265 cm-1 is narrow, and the Raman shift is 2 cm-1. In the PL spectra, the FWHM at 900 nm is narrow. Then the results show GaAs layer is highly structural quality. But if we can not measure the PL peak at 900 nm, or the FWHM of Raman spectra of TO peak at 265 cm-1 is not narrow, the GaAs layer is not crystallinity. Therefore, we can estimate the layer quality by Raman and PL spectra.

Arsenicals↗
PubMed2001

[Resistance of Mycobacterium fortuitum against varied physical factors and its survival in different surroundings].

OBJECTIVE: To observe the resistance of Mycobacterium fortuitum against some physical factors and its survival in different surroundings. METHODS: Bacterium solution of Mycobacterium fortuitum was added to the carriers, then it was treated in different interval of time and physical surroundings (high temperature, maximum pressure in ultraviolet ray, dry, sunshine). The treated specimen was cultured to observe the resistance of Mycobacterium fortuitum against physical factors. At the same time, some of bacterium solution were mixed into materials in different surroundings (water, wet soil, and dry soil). The specimen was cultured constantly in different time under the room temperature to observe the growth of Mycobacterium fortuitum in different surroundings. RESULTS: Mycobacterium fortuitum was killed at 60 degrees C in 135 minutes, 80 degrees C in 60 minutes, 100 degrees C in 5 minutes, and high pressure in 5 minutes (6.8 kg at 121 degrees C, 4.5 kg at 115 degrees C). It can also be killed under hot sunshine in one hour and under the ultraviolet ray at 105.5 microW/cm. Mycobacterium fortuitum can exist in water over 27 months, in wet and dry soil and in dry surroundings for more than one and a half year. With the extending of time, quantities of Mycobacterium fortuitum showed a trend of decline. CONCLUSIONS: Mycobacterium fortuitum possesses low resistance against high temperature, but higher resistance against ultraviolet ray. The germ shows stronger endurance in different surroundings and can exist for a long time.

Environment↗
PubMed2000

Single-column purification and bio-characterization of recombinant human parathyroid hormone-related protein (1-139).

Recombinant human parathyroid hormone-related protein (hPTHrP) (1-139) was expressed using the IMPACT T7 (intein-mediated purification with an affinity chitin-binding tag) system, allowing purification of free recombinant peptide in a single chromatographic step. This system utilizes an intein, which is a protein splicing element from the Saccharomyces cerevisiae VMA1 gene. The intein has been modified so that it undergoes a self-cleavage reaction at its N-terminus at low temperatures in the presence of 1,4-dithiothreitol (DTT). The cDNA encoding hPTHrP (1-139) was cloned into the pTYB1 vector to create an in-frame fusion at the N-terminus of the intein gene. The cDNA for the chitin-binding domain from Bacillus circulans is present at the C-terminus of intein for affinity purification of the three-part fusion protein on a chitin column. The recombinant plasmid was transfected into E. coli ER2566 cells and synthesis of the PTHrP fusion protein was induced with isopropyl-beta-D-thiogalactopyranoside (IPTG). This system produced pure hPTHrP (1-139) and an N-terminally truncated analogue, hPTHrP (27-139), as judged by sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blot analysis, N-terminal sequence analysis and mass spectroscopy. hPTHrP (1-139) stimulated cAMP accumulation in ROS 17/2.8 osteoblastic bone cells, whereas hPTHrP (27-139) failed to elicit a response. hPTHrP (1-139) also inhibited the growth of the breast cancer cell line MDA-MB-231; the magnitude of the response was comparable with that of synthetic hPTHrP (1-34) and (1-86). Neutralization of endogenous PTHrP and added hPTHrP (1-139) and N-terminal species with an anti-PTHrP antiserum completely abolished the growth inhibitory effects. These results indicate that the added peptides modulate cell growth by acting at the cell surface. Availability of recombinant hPTHrP (1-139) will allow further study of its biological function, as well as its structure.

Breast Neoplasms↗