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Hua Wu

Publications and source records attributed to Hua Wu.

At least 55 records · Page 3Linked to original sources
PubMed2004

Aurora A, meiosis and mitosis.

The Aurora family kinases are pivotal to the successful execution of cell division. Together they ensure the formation of a bipolar mitotic spindle, accurate segregation of chromosomes and the completion of cytokinesis. They are also attractive drug targets, being frequently deregulated in cancer and able to transform cells in vitro. In this review, we summarize current knowledge about the three family members, Aur-A, Aur-B and Aur-C. We then focus on Aur-A, its roles in mitotic progression, and its emerging roles in checkpoint control pathways. Aur-A activity can be controlled at several levels, including phosphorylation, ubiquitin-dependent proteolysis and interaction with both positive regulators, such as TPX2, and negative ones, like the tumor suppressor protein p53. In addition, work in Xenopus oocytes and early embryos has revealed a second role for Aur-A, directing the polyadenylation-dependent translation of specific mRNAs important for cell cycle progression. This function extends to post-mitotic neurons, and perhaps even to cycling somatic cells.

Animals↗
PubMed2004

PR-39, a porcine antimicrobial peptide, inhibits apoptosis: involvement of caspase-3.

The porcine antimicrobial peptide, PR-39, has several activities beyond its function of killing bacteria. Here we report that PR-39 alters macrophage viability by inhibiting apoptosis, which was induced by nutrient depletion, LPS stimulation or camptothecin treatment. This antiapoptotic effect was pronounced resulting in significant reductions in annexin-V binding to externalized phosphatidylserine and was associated with a decrease in caspase-3 activity. These findings suggest that PR-39, a porcine neutrophil-derived antimicrobial peptide, might function in the inflammatory milieu not only to kill bacteria, but also to aid in modulating the viability of inflammatory cells by regulating apoptosis.

Animals↗
PubMed2004

A twist code determines the onset of osteoblast differentiation.

Runx2 is necessary and sufficient for osteoblast differentiation, yet its expression precedes the appearance of osteoblasts by 4 days. Here we show that Twist proteins transiently inhibit Runx2 function during skeletogenesis. Twist-1 and -2 are expressed in Runx2-expressing cells throughout the skeleton early during development, and osteoblast-specific gene expression occurs only after their expression decreases. Double heterozygotes for Twist-1 and Runx2 deletion have none of the skull abnormalities observed in Runx2(+/-) mice, a Twist-2 null background rescues the clavicle phenotype of Runx2(+/-) mice, and Twist-1 or -2 deficiency leads to premature osteoblast differentiation. Furthermore, Twist-1 overexpression inhibits osteoblast differentiation without affecting Runx2 expression. Twist proteins' antiosteogenic function is mediated by a novel domain, the Twist box, which interacts with the Runx2 DNA binding domain to inhibit its function. In vivo mutagenesis confirms the antiosteogenic function of the Twist box. Thus, relief of inhibition by Twist proteins is a mandatory event precluding osteoblast differentiation.

Aging↗
PubMed2004

Evidence that activation of Src family kinase is not required for fertilization-associated [Ca2+]i oscillations in mouse eggs.

Recent evidence in marine invertebrate, frog, and zebrafish eggs suggests the involvement of a Src family kinase (SFK) in fertilization-induced Ca2+ release. In the present study, we have investigated whether activation of an SFK is required for initiation of intracellular Ca2+ ([Ca2+]i) oscillations in mouse fertilization. We detected a Hck-like protein and tyrosine-phosphorylated proteins in soluble and insoluble sperm fractions, respectively. However, the presence of these proteins did not correspond to the active fractions of porcine sperm extracts (pSE). Moreover, [Ca2+]i oscillations induced by pSE in mouse eggs were unaltered by pre-incubation of pSE with specific SFK inhibitors such as 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazol[3,4-d]-pyrimidine (PP2) or lavendustin A, despite the fact that the inhibitors were shown to be active both in vivo and in vitro. Another SFK inhibitor, peptide A, blocked oscillations when incubated with pSE prior to injection into eggs, but this inhibition required more than ten times the concentration reportedly required to inhibit SFK activity. In addition, pre-injection or pre-incubation of eggs with these inhibitors did not affect the ability of pSE to trigger [Ca2+]i oscillations in mouse eggs. Microinjection of a recombinant c-Src protein or mRNAs encoding constitutively active Src proteins did not induce [Ca2+]i release. Finally, when sperm and eggs, both of which were pre-treated with PP2, were fertilized, [Ca2+]i oscillations occurred normally. We can therefore conclude that activation of an SFK is neither necessary nor sufficient for triggering fertilization-induced [Ca2+]i oscillations.

Animals↗
PubMed2004

[Ultrafiltration with different membranes and respiratory function after cardiopulmonary bypass].

OBJECTIVE: To investigate the protective effect of ultrafiltration on pulmonary function after cardiopulmonary bypass (CPB) by comparing two different membranes used in the ultrafiltration. METHODS: Thirty patients undergoing cardiac surgery with CPB were randomly divided into adsorption group (n=15) and control group (n=15), and in the former group, AN69 membrane was used for ultra-infiltration, with polysulfone (PS) membrane adopted in the control group during CPB. Plateau airway pressure (P(Plateau)), peak airway pressure (P(Peak)), static pulmonary compliance (Cst), dynamic pulmonary compliance (Cdyn) and respiratory index (RI) were measured or calculated before and 5, 60, 120, and 240 min after CPB in each group respectively. RESULTS: During the period of 5 to 240 min after CPB, the increase in P(Plateau), P(Peak), RI and decrease in Cst and Cdyn were much more obvious and lasted for longer time in the adsorption group than in the control group (P<0.05). No operative death or hemoglobinuria occurred in these cases. CONCLUSION: Ultrafiltration with AN69 membrane more effectively reduces CPB-induced lung injury and improves the postoperative respiratory function than with PS membrane.

Adult↗
PubMed2004

[Correlation between uptake of 99Tcm-MIBI and expression of multidrug resistant protein in breast cancer].

OBJECTIVE: To assess the correlation between uptake of (99)Tc(m)-MIBI and expression level of multidrug resistant protein in breast cancer. METHODS: Thirty pathologically confirmed patients with primary invasive ductal carcinoma were examined by (99)Tc(m)-MIBI scintigraphy at 15 min and 90 min after injecting the tracer. The uptake of (99)Tc(m)-MIBI at the region of interest (ROI) was evaluated as tumor to normal background (T/N) ratio. Retention index (RI) was calculated from the early uptake ratio (EUR) and updelayed take ratio (DUR). The expression of P-glycoprotein (P-gp) and multidrug resistant-associated protein (MRP) was detected by immunohistochemistry and the results were expressed as optical density (A). The data were analyzed by t test, Pearson correlation and partial correlation analysis. RESULTS: The expression of P-gp and MRP in tumor tissue was 0.1183 +/- 0.0700 and 0.1195 +/- 0.0522, respectively. In group with RI < 0. the expression of P-gp and MRP was 0.2181 +/- 0.0384 and 0.1718 +/- 0.0479, respectively. In group with RI >/= 0, the expression of P-gp and MRP was 0.1057 +/- 0.0217 and 0.0967 +/- 0.0362, respectively. There were significant differences between the two groups (t = 6.61, P = 0.0001; t = 5.01, P = 0.002). There was positive correlation between P-gp and RI (r = -0.919, P = 0.001), DUR (r = -0.675, P = 0.001), MRP(r = 0.549, P = 0.001), respectively, but no correlation between P-gp and EUR (r = -0.097, P = 0.610). There was positive correlation between MRP and RI (r = -0.547, P = 0.002), but no correlation between MRP and EUR (r = 0.292, P = 0.117) or DUR (r = -0.173, P = 0.361). Partial correlation analysis showed that there was high positive correlation between P-gp and RI (r = -0.8847, P = 0.001), but no significant correlation between MRP and RI (r = -0.1296, P = 0.512). CONCLUSION: The study suggests that increased level of P-gp expression may contribute to a low accumulation of (99)Tc(m)-MIBI in breast cancer, but no correlation with the expression level of MRP. Thus (99)Tc(m)-MIBI scintigraphy may predict the MDR development associated with P-gp expression in breast carcinoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

[Alpha 2 codon 30 deletion (deltaGAG) causing non-deletional hemoglobin H disease in Guangxi province].

OBJECTIVE: To analyze genotypic profiles and understand the relationship between the genotype and phenotype of Hb H disease in Guangxi province. METHODS: Hematologic and Hb analyses on the cases were performed to detect their alpha thalassemia genotypes using PCR method and DNA sequencing. RESULTS: An unusual case was identified in one of the 298 patients with Hb H disease diagnosed in the First Affiliated Hospital of Guangxi Medical University from October 2002 to November 2003. The 25-year-old male patient, a native of Yulin in Guangxi province, had had jaundice and splenomegaly since childhood, and he had never received blood transfusion. Hematologic examinations revealed his hemoglobin 107 g/L, RBC 4.9+10(12) g/L, MCV 76.2 fl, MCH 21.8 pg, MCHC 287 g/L, HCT 0.373, reticulocyte 3%. Hb analysis showed the level of Hb H + Hb Bart's 34.41%. PCR and DNA sequencing confirmed the genotype of a deletion at codon 30 of alpha2 globin gene and SEA alpha-thalassemia-1. CONCLUSION: This unusual case had no anemia, but had higher level of Hb H and Hb Bart's when compared to those non-deletional Hb H disease cases such as Hb CS-H, HbQS-H and alpha2 codon 31 mutation combined with SEA alpha-thalassemia-1 previously reported in mainland China. The discovery and recognition of this gene mutation and related genotype and phenotype is of importance to the genetic counseling and prenatal diagnosis in Guangxi province where the incidence of alphathalassemia is very high.

Adult↗
PubMed2003

A simple model for the structure of fractal aggregates.

Structural properties of small aggregates containing up to 100 particles have been studied through detailed Monte Carlo cluster-cluster aggregation simulations in both diffusion-limited and reaction-limited conditions. First, the radius of gyration, the radius of the smallest sphere encompassing the cluster, and the particle-particle correlation function, g(r), have been computed based on the positions of all the particles in the cluster, and their fractal scaling has been analyzed. Then, an empirical model has been developed to simulate the g(r) function for aggregates of any size and used to determine the corresponding structural properties and scattering structure factors. Finally, in order to illustrate the application of the structural properties thus computed, two experiments on diffusion-limited aggregation have been performed, and the average scattering structure factors have been measured as a function of time using a small-angle light-scattering device. The obtained average scattering structure factors have been simulated using the Smoluchowski population balance equations, using the single aggregate structural properties and scattering structure factor predicted by the developed empirical g(r) model.

Journal Article↗
PubMed2003

Hydrodynamic radius of fractal clusters.

The Kirkwood-Riseman theory has been used to derive an analytical formula for the evaluation of the hydrodynamic radii of fractal clusters. The proposed relation is based on knowledge of the particle-particle correlation function and can be applied to clusters containing any number of particles larger than 4. The calculated values of the hydrodynamic radius are compared with the results of other theoretical approaches proposed in the literature, as well as several experimental data. Finally, the developed relation has been used in connection with a population balance equation model that computes the clusters' mass distribution to estimate the average hydrodynamic radius for a population of fractal clusters of different sizes. The obtained results have been compared to suitable experimental data for a silica colloidal suspension aggregating under reaction-limited conditions.

Journal Article↗
PubMed2003

Aggregation kinetics of polymer colloids in reaction limited regime: experiments and simulations.

The kinetics of reaction-limited cluster aggregation of fluorinated polymer colloids in a broad range of particle volume fractions has been investigated experimentally by measuring independently the Fuchs stability ratio W and the time evolution of both the average radius of gyration and the average hydrodynamic radius of the aggregates mass distribution. The W value is determined from the aggregation rate at the very initial stage of the aggregation, where the presence of triplets is negligible. The time evolutions of and are then simulated using the cluster mass distribution calculated from the population balance equations with various aggregation kernels proposed in the literature. It is found that, when the measured W value is used, the only kernels that can correctly simulate the experimental results are the product kernel and the one derived by Odriozola et al. (Europhys. Lett. 53 (2001) 797), with some proper tuning of the exponent in the kernel. For the particle volume fraction phi<1%, the obtained value for the exponent is 0.4 and independent of phi, while it tends to decrease for larger phi values, most likely indicating a significant effect of multi-body interactions on the aggregation kinetics.

Journal Article↗
PubMed2003

Genome-wide single-nucleotide polymorphism analysis defines haplotype patterns in mouse.

The nature and organization of polymorphisms, or differences, between genomes of individuals are of great interest, because these variations can be associated with or even underlie phenotypic traits, including disease susceptibility. To gain insight into the genetic and evolutionary factors influencing such biological variation, we have examined the arrangement (haplotype) of single-nucleotide polymorphisms across the genomes of eight inbred strains of mice. These analyses define blocks of high or low diversity, often extending across tens of megabases that are delineated by abrupt transitions. These observations provide a striking contrast to the haplotype structure of the human genome.

Animals↗
PubMed2003

Genetic differentiation and subspecies development of the giant panda as revealed by DNA fingerprinting.

Over the last 100 years giant pandas (Ailuropoda melanoleuca) have been separated into six completely isolated mountain ranges. DNA fingerprinting revealed different differentiation patterns in giant pandas, including early-stage, late-stage, recent divergence and recent genetic depression. A separation around 10 000 years ago resulted in highly significant differences in DNA fingerprints and morphological characteristics between Qinling and Sichuan populations. Supported by morphological differences, the genetic data were used to classify the Qinling population as a new subspecies, A. m. qinlingensis, while the Sichuan populations were classified into the original subspecies, A. m. melanoleuca. Thus, the Qinling population deserves management as a separate unit. In the Sichuan populations, two management units were defined, including Qionglai-Minshan and Daxiangling-Xiaoxiangling-Liangshan. Our data suggest urgent measures are needed to establish green corridors between subpopulations in each mountain range to increase gene flow and genetic variation to ensure long-term survival.

Animals↗
PubMed2003

Using Tc-99m MIBI scintimammography to differentiate nodular lesions in breast and detect axillary lymph node metastases from breast cancer.

OBJECTIVE: To test the clinical value of using Tc-99m MIBI scintimammography (Tc-99m MIBI SMM) to differentiate nodular lesions in breasts and detect axillary lymph node metastases of breast cancer. METHODS: The subjects consisted of sixty female patients exhibiting unilateral palpable breast mass. The early and delay static acquisitions were undertaken in all subjects at 10 and 90 min after injection with Tc-99m MIBI. The acquisition included three positions: anterior supine, left lateral prone and right lateral prone. A special device for SMM which was developed by our laboratory was used. The ratio of [(T-B)/(NT-B)] was calculated as radioactivity of mass to that of opposite corresponding tissue, and [(T-B)/(NT-B)] > or = 1.21 was used as the cut-off for semi-quantitative discrimination of malignancy from benignity in semi-quantitative analysis. The final diagnosis was obtained from histology examination in all subjects. RESULTS: Using Tc-99m MIBI SMM to differentiate between nodular lesions in breasts, the diagnostic sensitivity and specificity were 92.9% and 90.6% respectively, the positive predictive value 89.7%, the negative predictive value 93.5%, and the accuracy 91.7%. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy obtained with Tc-99m MIBI SMM for detecting axillary lymph node metastases were 83.3%, 86.1%, 80%, 88.6% and 85% respectively. CONCLUSIONS: It is suggested that Tc-99m MIBI SMM may be not only valuable in differentiating malignant lesions from benign nodular masses of breast, but also helpful in detecting axillary lymph node metastases of breast cancer.

Adolescent↗
PubMed2003

[Detection of anti-HEV IgG and analysis of partial HEV RNA sequence].

OBJECTIVES: To investigate HEV infection in swine and the genotype relationship between swine and human HEV. METHODS: Anti-HEV IgG antibody was detected in the sera of swine using enzyme linked immunoassay (EIA), and HEV RNA was amplified by reverse transcription nested polymerase chain reaction (RT-nPCR). The Vector NTI Suite 7 and TreeView softwares were used for nucleotide sequences phylogenetic analysis of HEV isolated from human and swine. RESULTS: The anti-HEV IgG positive rate was 16.67% (18/108). Among the 18 anti-HEV IgG positive sera, 2 sequences (11.11%, called S18 and S43, respectively) of HEV ORF1 (102-387bp) were amplified, with the identity of 99% between them. They had 76% to 77%, 78%, 76% to 79%, 85% to 86%, 77%, 80%, 79% and 75% - 79% homology at the nucleotide level with human HEV genotypes 1 to 8, respectively. One (S18) of them was also amplified out in ORF2 region (5,994-6 297bp) and showed 76% to 78%, 74%, 74% to 77%, and 85% to 94% identity with human HEV genotypes 1 to 4 at the nucleotide level, respectively. CONCLUSION: HEV sequences isolated from swine belong to human HEV genotype 4.

Animals↗
PubMed2003

[Clinical analysis of gastroesophageal reflux induced cough].

OBJECTIVE: To investigate the clinical features, diagnosis and management of gastroesophageal reflux induced cough (GERC). METHODS: The continuous ambulatory esophageal pH measurement was performed for 24 hour in 41 cases with chronic cough who had normal chest roentgenographic presentation, negative histamine provocation test and no abnormality of nasal cavity. The symptom association probability (SAP) was adopted to analyze the correlation of cough with gastroesophageal reflux. The anti-reflux treatment was given for 12 weeks to those patients with Demeester score >or= 14.72 and/or SAP >or= 75%. RESULTS: Twenty six out of 41 cases were diagnosed as patients with gastroesophageal reflux. The cough was completely cured in 12 cases after antireflux treatment. The SAP of cough in this cured group (proximal probe 0.75 +/- 0.21, distal probe 0.91 +/- 0.12, respectively) was significantly higher than that of patients who failed in response to antireflux treatment (proximal probe 0.36 +/- 0.31, distal probe 0.47 +/- 0.30, respectively, P < 0.05). CONCLUSION: The gastroesophageal reflux may be an independent factor which could induce chronic cough. Not only the frequency and severity of gastroesophageal reflux but also the SAP were helpful in making the diagnosis of GERC. Satisfied effect was achieved after sufficient anti-reflux treatment in patients with GERC.

Adult↗
PubMed2003

[Radionuclide reporter gene imaging].

Molecular nuclear imaging techniques are currently being developed to map the topography and level of gene expression following gene therapy. To date, two radionuclide-based imaging strategies have been investigated--using reporter genes encoding either intracellular enzymes or cell-surface receptors. In this article, we discuss these two reporter gene imaging systems that have been developed to detect gene expression noninvasively.

Gene Expression Regulation↗