Biomedical subjects

Zheng Zhang

Publications and source records attributed to Zheng Zhang.

At least 37 records · Page 2Linked to original sources

PubMed2006

Differential restoration of myeloid and plasmacytoid dendritic cells in HIV-1-infected children after treatment with highly active antiretroviral therapy.

Numerical and functional deficits in myeloid (mDC) and plasmacytoid dendritic cell (pDC) subsets have been found in both adult and pediatric HIV-1 carriers. Whether these impaired DC subsets can be restored after treatment with highly active antiretroviral therapy (HAART) is currently unknown, especially in HIV-1-infected children. In this report, we characterized mDC and pDC subsets in 18 HIV-1-infected children who received HAART treatment and compared them with those in 6 untreated HIV-1-infected children and 27 HIV-1-uninfected healthy children. Among children treated with HAART, 11 were found to suppress HIV-1 replication successfully below the detection limit (HAART-suppressed group) while the remaining 7 failed (HAART-failure group). In HAART-suppressed children, a gradual and complete restoration of the frequency and function of mDCs was observed while the recovery of pDCs was only partial. However, mDC and pDC subsets in HARRT failure children were indistinguishable from the HAART-naive infected children. We also found that mDC frequency and IFN-alpha-releasing capacity of pDC positively correlated with CD4 T cell percentages in all HIV-1-infected children. In HAART-naive children, the mDC frequency correlated the HIV-1-specific CTL frequency. Our findings suggest that HAART has a differential impact on the restoration of mDC and pDC subsets. These findings may help guide the development of HIV-1-specific immune therapy aimed at fully restoring host immune function in chronically HIV-1-infected children.

Adolescent↗

PubMed2006

[The role of protein tyrosine phosphatases Shp-2 involved in the formation of the neuromuscular junction].

OBJECTIVE: To investigate the involvement of protein tyrosine phosphatases Shp-2 in regulating postsynaptic signaling at the NMJ. METHODS: Cultured C2 mouse myotubes were used to mimic NMJ formation; immunoprecipitation, immuno-blot, RNA interference and immunofluorescent labeling were used in this study. RESULTS: We first showed that the general tyrosine phosphatase inhibitor pervanadate functionally activated MuSK and enhanced both agrin-independent and agrin-dependent AChR clustering in muscle cells: the MuSK band at 115 kD showed increased tyrosine phosphorylation after pervanadate treatment; 10 micromol/L pervanadate increased AChR clustering (mean = 6.43/cell) more than six-fold compared with control (mean = 0.96/cell), P < 0.0001, t-test; inclusion of pervanadate with agrin increased the size of agrin-induced clusters (difference = 1.53-fold, P < 0.0001, t-test) without significantly increasing the number of clusters (P = 0.08, t-test). Next, by immuno-screening we identified the SH2 domain-containing phosphatase Shp2 as a major tyrosine phosphatase in C2 myotubes and demonstrated that its selective down-regulation by RNA interference increased MuSK activation and AChR clustering: MuSK phosphorylation observed in the presence of pervanadate alone was increased in Shp2-depleted cells relative to control cells; AChR clusters in untreated myotubes were counted and data pooled from four experiments showed a doubling of their number (2.21-fold) in cells transfected with the Shp2 siRNA (n = 198) compared to those transfected with the control siRNA (n = 220); the number of AChR clusters was also increased in Shp2 siRNA-transfected cells compared to controls following treatment with pervanadate (1.5-fold; n = 149 cells) and agrin (1.41-fold; n = 125), P < 0.001, t-test. We also asked how Shp2 affect AChR clustering after increasing Shp2 activity: C2C12 cells were transfected with Shp-2 active form (E76A) and wild type Shp2 (used as control) respectively, average length of AChR clusters in active form (E76A) was decreased about 20% compared with wild type Shp2, P < 0.01, t-test. CONCLUSION: These results suggest that Shp2 functions in a feedback loop to regulate agrin/MuSK signaling and these findings highlight the importance of protein tyrosine phosphatases in postsynaptic signaling at the NMJ and provide insights into how balancing actions of protein kinases and phosphatases may determine the formation of synaptic specializations in the developing nervous system.

Agrin↗

PubMed2006

Binding studies of molecular linkers to ZnO and MgZnO nanotip films.

Two bifunctional linkers, a rigid-rod p-ethynyl-isophthalic acid capped with a Ru(II)-polypyridyl complex and 3-mercaptopropionic acid, were covalently bound to ZnO nanotip films grown by metal-organic chemical vapor deposition (MOCVD) technology. This highly vertically aligned, crystalline form of ZnO had not been functionalized before. The binding was studied by Fourier transform (FT) IR and UV spectroscopies and probed, in the case of the Ru complex, by static and dynamic fluorescence quenching. The molecules did bind through the carboxylic acid groups, and the FT-IR attenuated total reflectance spectra are indicative of a bidentate carboxylate binding mode. Other molecules (heptanoic acid, isophthalic acid, and trimethoxy(2-phenylethyl)silane) were also bound to the ZnO nanotips. A comparison was made with epitaxial ZnO films grown by MOCVD and ZnO mesoporous films prepared from colloidal solutions to investigate the effect of the ZnO morphology. The ZnO nanotips were excellent binding substrates, particularly for the rigid-rod linker. Since ZnO films are etched at low pH (< 4), novel nanotip films made of ternary MgxZn1-xO, which is formed by alloying ZnO with MgO and is more resistant to acids, were developed. The MgxZn1-xO nanotip films were employed to use linkers with acidic groups and to study the effect of pH pretreatment of the surface on the binding.

Journal Article↗

PubMed2006

Biodistribution and localization of iodine-131-labeled metuximab in patients with hepatocellular carcinoma.

PURPOSE: Radioimmunotherapy may improve the outcome of hepatocellular carcinoma (HCC) patients by delivering targeted radiation to liver lesion tissue while relatively sparing nontarget tissues. This study was designed to observe the biodistribution, localization and imaging characteristics of 131I -labeled Metuximab in 24 patients with HCC to determine the diagnostic and therapeutic potential of this antibody. METHODS: Twenty-four HCC patients were randomly divided into three groups to receive 18.5, 27.75 and 37 MBq/kg of 131I-labeled Metuximab per kilogram of body weight, respectively. 99mTc-sodium phytate was administered intravenously and the single photon emission computed tomography (SPECT) scanning was performed. After 48 h, 131I -labeled Metuximab was injected by hepatic artery intubation, and SPECT scan performed at 7 d. The percentage of absorbed 131I (%ID) and the time-dependent 131I tumor:nontumor tissue (T/NT) ratios were calculated at 12, 48, 96 and 192 h after injection. RESULTS: The positive Imaging result of MAb scanning in 24 patients showed that the iodine 131 conjugated to Metuximab was apparently accumulated more in hepatoma. Biodistribution studies of 131I-Metuximab in trial I demonstrated that the comparable % ID uptake in tumor (with a T/NT ratio at 12, 48, 96 and 192 h) to that in such normal organs, as thyroid, heart, lung, spleen and intestines were all more than one. The optimal imaging time for the highest T/NT ratio in liver was at 192 h. CONCLUSION: 131I-labeled Metuximab could deliver relatively selective radiation to tumor tissues and may have potential efficacy in relieving hepatocellular carcinoma.

Adult↗

PubMed2006

Thermo-sensitive transition of monomethoxy poly(ethylene glycol)-block-poly(trimethylene carbonate) films to micellar-like nanoparticles.

Monomethoxy poly(ethylene glycol)-block-poly(trimethylene carbonate) (mPEG(3)-PTMC(11), M(n) of mPEG=3.1 x 10(3) and M(n) of PTMC=10.8 x 10(3)g/mol) was synthesized by ring-opening polymerization of TMC using mPEG(3) as an initiator and stannous octoate as a catalyst. The block copolymer has a broad melting range with a peak at 49.5 degrees C and a heat of fusion of 47.6J/g. The heat of fusion normalized to the mPEG content is higher than that of the mPEG(3) polymer, suggesting that PTMC segments are also semi-crystalline. The mPEG(3)-PTMC(11) films were stable in water at room temperature, whereas at 37 degrees C the film specimens disintegrated and the amphiphilic block copolymer self-assembled into micellar-like nanoparticles with average sizes up to 210nm. The critical association concentration (CAC) of the formed micellar-like particles is 1.35 x 10(-3)mg/ml. The average size and polydispersity index of the formed mPEG(3)-PTMC(11) nanoparticles depend on temperature and storage time: the values decrease with increases in temperature and in storage time. By co-dissolving dexamethasone with mPEG(3)-PTMC(11) during the film preparation, micellar-like nanoparticles loaded with dexamethasone can be obtained after the film to micellar-like nanoparticles transition. A high loading efficiency of 93.3 wt.% was achieved. The sustained release of the drug was complete in 20d.

Delayed-Action Preparations↗

PubMed2006

Highly protein-resistant coatings from well-defined diblock copolymers containing sulfobetaines.

Three well-defined diblock copolymers of poly(sulfobetaine methacrylate) [poly(SBMA)] and poly(propylene oxide) (PPO) were synthesized by the sequential addition of SBMA monomer to fixed amounts of PPO using an atom transfer radical polymerization method and varying poly(SBMA) lengths. These copolymers were characterized by 1H NMR and aqueous gel permeation chromatography. These copolymers were physically adsorbed onto a surface plasmon resonance (SPR) sensor surface covered by methyl-terminated self-assembled monolayers, followed by the in situ evaluation of protein adsorption on the adsorbed copolymers. It is found that the behavior of the protein adsorption depends on the molecular weight of the copolymers. Results show that the diblock copolymers containing poly(SBMA) can be highly protein resistant when surface SBMA densities are well controlled. Thus, copolymers containing zwitterionic groups are ideal for resisting protein adsorption when the surface density of zwitterionic groups is controlled.

Adsorption↗

PubMed2006

Poly(trimethylene carbonate) and monomethoxy poly(ethylene glycol)-block-poly(trimethylene carbonate) nanoparticles for the controlled release of dexamethasone.

In this study, single emulsion and salting out methods were employed to prepare poly(trimethylene carbonate) (PTMC) and monomethoxy poly(ethylene glycol)-block-poly(trimethylene carbonate) (mPEG-PTMC) nanoparticles. Well-defined nanoparticles of a PTMC homopolymer were prepared using poly(vinyl alcohol) (PVA) as a stabilizer. The average size of the nanoparticles can be adjusted by varying the stirring speed and polymer concentration. These particles can be readily freeze-dried and redispersed, with little influence on the average particle size and size distribution. Nanoparticles based on amphiphilic mPEG-PTMC can be prepared without an additional stabilizer. In this case, the size of the obtained nanoparticles did not vary much and ranged between 95 and 120 nm. These nanoparticles could be freeze-dried and redispersed as well. Using the salting out method, dexamethasone was loaded into PTMC and mPEG-PTMC nanoparticles at a highest efficiency of respectively 54% and 88%. With the single emulsion method, the loading efficiencies were, respectively, 91% and 72%. These drug-loaded particles were stable in time for at least 20 weeks. It was found that the release of dexamethasone from these nanoparticles was diffusion-controlled and could be sustained for 14 to 60 days. Depending on the nature of the polymer employed and the preparation method, dexamethasone diffusion coefficients varied between 4.8 x 10(-18) and 22.6 x 10(-18) cm(2)/s.

Anti-Inflammatory Agents↗

PubMed2006

Enhanced de novo neurogenesis and dopaminergic neurogenesis in the substantia nigra of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinson's disease-like mice.

Research reports on de novo neurogenesis, particularly dopaminergic (DA) neurogenesis in the adult mammalian substantia nigra (SN), remain very controversial. For this reason, we used the nestin second intron enhancer-controlled LacZ reporter transgenic mouse model coupled with the 1-methyl-4-phyenyl-1,2,3,6-tetrahydropyridine (MPTP) lesion system to investigate whether there are neurogenesis and DA neurogenesis in the SN of the adult normal and Parkinson's disease (PD)-like mice. First, we demonstrated the presence of neural progenitor cells (NPCs), basal levels of neurogenesis, and DA neurogenesis in the normal adult mouse SN. Second, we showed that there is not only a significant increase in the number of NPCs but also a dramatic increase of neurogenesis from the NPCs in the SN and the midline region adjacent to the SN of the PD-like mice compared with that of normal controls. More importantly, we also demonstrated that there is an increase of DA neurogenesis in the SN of the MPTP-lesioned mice. Third, we showed that the increased DA neurogenesis in the MPTP-lesioned mice was derived from the NPCs and 5-bromodeoxyuridine-positive cells, suggesting that multiple stem cell lineages may contribute to the enhanced neurogenesis in the adult SN. Taken together, these results establish that there are basal levels, albeit low, and increased levels of de novo neurogenesis and DA neurogenesis in the SN of the adult normal and PD-like mice, respectively. The increased NPCs in the MPTP-lesioned mice further suggest that experimental approaches to promote de novo neurogenesis may provide an effective therapy for PD by functional replacement of degenerated DA neurons.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed2006

Apoptosis profiles in benign prostatic hyperplasia: close associations of cell kinetics with percent area density of histologic composition.

OBJECTIVES: To investigate the possible correlations of apoptosis and apoptosis-associated factors, including the apoptotic index (AI), proliferation index (PI), and expression of Bcl-2 and caspase 3, with the percent area density of epithelium and stroma in benign prostatic hyperplasia (BPH). METHODS: A total of 60 patients with histologically determined BPH were investigated. The percent area density of epithelium and stroma was determined using a computerized image analysis system after Masson's trichrome staining. Apoptosis was detected using the AI through the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay. Cell proliferation was determined using the PI through Ki-67 immunostaining. The expression of Bcl-2 and caspase 3 was immunohistochemically examined. Double-label immunofluorescent staining was performed to assess co-localization of Bcl-2 and caspase 3. RESULTS: The stroma/epithelium ratio ranged from 4.6 to 6.3 (average 5.2) in BPH. A greater stromal PI was closely related to the percent area density of stroma (P <0.01), and a greater epithelial AI was reversely related to the percent area density of the epithelium (P <0.05). Bcl-2 and caspase 3 expression was detected in 50 (80%) and 48 (75%) of 60 BPH samples, respectively. The expression of Bcl-2 and caspase 3 was not related to PI, AI, or the percent area density of the BPH components (P >0.05). Immunofluorescence analysis revealed co-localization of Bcl-2 and caspase 3 in the serial sections of BPH specimens that already showed either Bcl-2 or caspase 3 expression. CONCLUSIONS: The development of BPH may be associated with both stromal growth due to active stromal cell proliferation and epithelial growth due to reduced glandular apoptosis.

Aged↗

PubMed2006

Dual-functional biomimetic materials: nonfouling poly(carboxybetaine) with active functional groups for protein immobilization.

We introduce a dual-functional biocompatible material based on zwitterionic poly(carboxybetaine methacrylate) (polyCBMA), which not only highly resists protein adsorption/cell adhesion, but also has abundant functional groups convenient for the immobilization of biological ligands, such as proteins. The dual-functional properties are unique to carboxybetaine moieties and are not found in other nonfouling moieties such as ethylene glycol, phosphobetaine, and sulfobetaine. The unique properties are demonstrated in this work by grafting a polyCBMA polymer onto a surface or by preparing a polyCBMA-based hydrogel. PolyCBMA brushes with a thickness of 10-15 nm were grafted on a gold surface using the surface-initiated atom transfer radical polymerization method. Protein adsorption was analyzed using a surface plasmon resonance sensor. The surface grafted with polyCBMA very largely prevented the nonspecific adsorption of three test proteins, that is, fibrinogen, lysozyme, and human chorionic gonadotropin (hCG). The immobilization of anti-hCG on the surface resulted in the specific binding of hCG while maintaining a high resistance to nonspecific protein adsorption. Transparent polyCBMA-based hydrogel disks were decorated with immobilized fibronectin. Aortic endothelial cells did not bind to the polyCBMA controls, but appeared to adhere well and spread on the fibronectin-modified surface. With their dual functionality and biomimetic nature, polyCBMA-based materials are very promising for their applications in medical diagnostics, biomaterials/tissue engineering, and drug delivery.

Adsorption↗

PubMed2006

Restoring warped document images through 3D shape modeling.

Scanning a document page from a thick bound volume often results in two kinds of distortions in the scanned image, i.e., shade along the "spine" of the book and warping in the shade area. In this paper, we propose an efficient restoration method based on the discovery of the 3D shape of a book surface from the shading information in a scanned document image. From a technical point of view, this shape from shading (SFS) problem in real-world environments is characterized by 1) a proximal and moving light source, 2) Lambertian reflection, 3) nonuniform albedo distribution, and 4) document skew. Taking all these factors into account, we first build practical models (consisting of a 3D geometric model and a 3D optical model) for the practical scanning conditions to reconstruct the 3D shape of the book surface. We next restore the scanned document image using this shape based on deshading and dewarping models. Finally, we evaluate the restoration results by comparing our estimated surface shape with the real shape as well as the OCR performance on original and restored document images. The results show that the geometric and photometric distortions are mostly removed and the OCR results are improved markedly.

Algorithms↗

PubMed2006

Cloning, expression, and identification of immunological activity of an allergenic protein in tartary buckwheat.

A cDNA fragment encoding a 24 kDa allergenic protein in tartary buckwheat was obtained using reverse transcription PCR, 3'-rapid amplification of cDNA ends (RACE), and nest PCR. The cDNA clone contained 768 nucleotides, including 588 nucleotides in the open reading frame (ORF) and 180 nucleotides in the 3'-terminal sequence. The ORF encoded a functional protein of 195 amino acids. It shared 95% and 93% nucleotide homology with the allergenic storage protein and a legumin-like protein from common buckwheat respectively. The encoding region was expressed in host strain Escherichia coli BL21 (DE3) induced by IPTG at 28 degrees C. The inclusion bodies of recombinant protein obtained were analyzed by western blot and purified by affinity chromatography. The purity of target protein reached above 95%. After they were refolded by step-wise dialysis, 68% of the inclusion bodies reached soluble state. An analysis of immunological activity showed that the recombinant protein had a specific IgE binding activity. This is the first report of the molecular cloning and expression of the major allergen from tartary buckwheat.

Antigens, Plant↗

PubMed2006

DNA immobilization and SAW response in ZnO nanotips grown on LiNbO3 substrates.

DNA immobilization enhancement is demonstrated in a structure consisting of ZnO nanotips on 128 degrees Y-cut LiNbO3. The ZnO nanotips are grown by metalorganic chemical vapor deposition (MOCVD) on the top of a SiO2 layer that is deposited and patterned on the LiNbO3 SAW delay path. The effects of ZnO nanotips on the SAW response are investigated. X-ray diffraction and scanning electron microscopy are used to analyze the ZnO nanotips, which are of single crystalline quality, and they are uniformly aligned with their c-axis perpendicular to the substrate surface. The photoluminescence (PL) spectrum of the ZnO nanotips shows strong near bandedge transition with insignificant deep level emission, confirming their good optical property. DNA immobilization enhancement is experimentally validated by radioactive labeling tests and SAW response changes. The ZnO nanotips enhance the DNA immobilization by a factor of 200 compared to ZnO film with flat surface. DNA hybridization with complementary and noncomplementary second strand DNA oligonucleotides is used to study the selective binding of the structure. This device structure possesses the advantages of both traditional SAW sensors and ZnO nanostructures.

Biosensing Techniques↗

PubMed2006

[Investigation of nutrition and feeding status among children under 2 years in Beijing].

OBJECTIVE: To investigate the nutrition status, breast feeding and complementary feeding among children under 2 years of age in Beijing. METHODS: A stratified cluster randomly sampling method was used. After having got the compliance a questionnaire survey was carried out to 422 children < 2 year-old in total 18 districts of Beijing. RESULTS: The average infant birth weight was 3325 g, the rate of weight (2500 g and > or = 4000 g were 2.8% and 13.0% respectively. The rate of exclusive breast-feeding, partial breast-feeding, bottle-feeding of infant under 4 months was 56.6%, 33.9% and 9.5% respectively. The average weaning time was 7.4 months. The rate of complementary feeding of infant up to 6 months was 99.4%. The average ages for addition of complementary feeding such as cereal, vegetable and fruit, egg, oil, nutrients in rural areas were later than those in urban. CONCLUSION: It is important to promote breast feeding and improve complementary feeding by education and intervention.

Bottle Feeding↗

PubMed2006

[Comparison of wavefront aberrations in pseudophakia with three types of intraocular lenses implantation].

OBJECTIVE: We compared wavefront aberration in pseudophakic eyes with 3 types of intraocular lenses (IOLs) implantation in order to obtain an objective evaluation of the optical quality of these pseudophakic eyes. METHODS: This prospective study comprised 76 cataract patients (80 eyes) who had phacoemulsification surgery. The intraocular lenses of AcrySof MA30BM, Hydroview H60M, and Canon Staar, KS-1 were implanted in the patients at the numbers of 26, 27 and 27 eyes in each group respectively. Three months after cataract surgery, aberrations in the eyes were measured in un-dilated pupil using a Hartmann-Shack-type aberrometer (Asclepion-Meditec). The same measurements were done in 26 normal phakic eyes in age-matched persons. Individual Zernike polynomials, coma-like aberration, spherical aberration, the RMS value of total aberrations and total high order aberrations in the each group were compared. RESULTS: The total high order aberrations (the RMS value of 3rd and 4th aberrations) in AcrySof group was higher than Canon Staar group (P = 0.011), and the Z (3, 1) Zernike coefficient in AcrySof group was significant difference compared with Hydroview group (P = 0.038). CONCLUSION: No significant differences in higher-order aberrations among eyes are demonstrated after implantation with 3 types IOLs in un-dilated pupil. The results suggest that there is no difference in the retinal image of pseudophakic eyes with 3 types of IOLs in regular condition.

Aged↗

PubMed2006

[Identification of circulating plasmacytoid dendritic cells in chronic HBV-infected patients].

OBJECTIVE: To investigate the features of circulating plasmacytoid dendritic cells (pDCs) in patients with chronic hepatitis B for a better understanding of the immunopathogenesis of HBV infection. METHODS: Fresh blood samples were collected from 20 patients with chronic hepatitis B (CHB) and from 15 healthy individuals who served as controls. pDCs were isolated from peripheral blood mononuclear cells (PBMCs) using immunomagnetic assay and detected by flow cytometry. Fresh PBMCs and isolated pDCs were stimulated in vitro using CpG ODN2216. The supernatants were measured for IFNa production using ELISA. RESULTS: The peripheral pDCs frequency in CHB patients (0.192%+/-0.110%) was markedly lower than that in the healthy controls (0.287%+/-0.142%). After being pulsed with CpG ODN2216, the isolated pDCs produced lower levels of IFNa and expressed lower levels of CD80 and CD40 in the CHB patients when compared to those of the healthy controls. The level of IFNa was (972.6+/-705.5) pg/ml in the patients and (3 142.9+/-1 292.2) pg/ml in the controls. Moreover, the pDCs frequency was reversely correlated with serum ALT levels in these HBV infected patients. CONCLUSION: The reduced number and impaired function of circulating pDCs in patients with CHB may be related to their disease progression.

Adult↗

PubMed2006

[Inhibition of expression of CCR5 and CXCR4 on cells by adenovirus-mediated antisense RNA].

OBJECTIVE: To suppress the expression of CCR5 and CXCR4, the co-receptors for human immunodeficiency virus type 1 ( HIV-1), and thus inhibit HIV-1 from entering cells. METHODS: DNA fragments encoding either CCR5 or CXCR4 were amplified from healthy human peripheral blood mononuclear cells (PBMCs) by reverse transcript polymerase chain reaction (RT-PCR) and sequencing was performed. Correct fragments were inserted into Shuttle plasmid inversely, which was recombined with backbone plasmid containing homologous adenoviral genome in E. coli BJ5183. The recombinant plasmids were transfected into 293 cells in which they were packaged and amplified. Recombinant adenoviruses containing antisense RNA of CCR5 or CXCR4 were obtained and identified by RT-PCR, and the titres of them were determined by cytopathic effect (CPE) method. The U937 and MT4 cells were infected by recombinant adenoviruses containing antisense RNA of CCR5 (multiplicity of infection, MOI = 100) and CXCR4 (MOI = 200), respectively. The expression of co-receptors on infected cell was measured by fluorescence activated cell sorter at 24, 48, 72 hours and 10 days after infection. In addition, the chemotactic activity and proliferation of infected cells were detected with Boyden chamber and 3H incorporation respectively. RESULTS: We constructed the recombinant plasmids and obtained the recombinant adenoviruses which contained antisense RNA of CCR5 or CXCR4 and were designated as pAd-antiR5 and pAd-antiX4 respectively. The titers of recombinant adenoviruses pAd-antiR5 and pAd-antiX4 were 5 x 10" PFU/ml and 7 x 10(10) PFU/ml, respectively. The expression rate of CCR5 on U937 cells decreased from 82. 10% (blank control) to 1.12% (Ad-antiR5 infected) , and that of CXCR4 on MT4 cells decreased from 42% (blank control) to 1.03% (Ad-antiX4 infected) 24 hours later. The expression rates of CCR5 on Ad-antiR5 infected U937 cells were 1.02% , 1.26% , 1.23% at 48 hours, 72 hours, and 10 days later, respectively. The expression rates of CXCR4 on Ad-antiX4 infected MT4 cells were 1.13%, 1.17%, 1.22% at 48 hours, 72 hours, and 10 days later, respectively. Moreover, the recombinant adenovirus had no effects on chemotactic activity and proliferation of the cells. CONCLUSION: The recombinant adenovirus containing antisense CCR5 or CXCR4 can remarkably decrease the expression of co-receptors for HIV-1 on U937 or MT4 cells without affecting their chemotactic activities and proliferative abilities.

Adenoviridae↗

PubMed2005

Evidence for capacitative and non-capacitative Ca2+ entry pathways coexist in A10 vascular smooth muscle cells.

It is generally thought that receptor-operated Ca2+ entry is related to store-operated or capacitative Ca2+ entry mechanism. Recent evidence suggests that non-capacitative Ca2+ entry pathways are also involved in receptor activated Ca2+ influx in many different kinds of cells. In this study, we studied whether alpha1-adrenoreceptor (alpha1-AR)-activated Ca2+ entry is coupled to both capacitative and non-capacitative pathways in A10 vascular smooth muscle cells by fura-2 fluorescence probe and conventional whole-cell patch clamp techniques. We found that both thapsigargin (TG) and phenylephrine (Phe) induced transient increase in cytoplasmic Ca2+ concentration ([Ca2+]i) in Ca2+-free medium, and subsequent addition of Ca2+ evoked a sustained [Ca2+]i rise. When the membrane potential was held at -60 mV, both TG and Phe activated inward currents, which were inhibited by GdCl3(Gd3+), 0Na+/0Ca2+ solution and 1-{beta[3-(4-mehtoxyphenyl)propoxy]-4-methoxypheneth-yl}-1H- imidazole hydro-chloride (SK&F96365), but not by nifedipine. When Ca2+ store was depleted by TG in Ca2+-free solution, Phe failed to further evoke [Ca2+]i rise. However, when capacitative Ca2+ entry was activated by TG in the medium containing Ca2+, 10 microM Phe further increased [Ca2+]i. At the same concentration, TG activated an inward cation current, subsequent addition of Phe also further induced an inward cation current. Furthermore, the amplitudes of [Ca2+]i increase and current density induced by Phe in the presence of TG were less than that induced by Phe alone. Our results suggest that both capacitative and non-capacitative Ca2+ entry pathways are involved in Ca2+ influx induced by activation of alpha1-AR in A10 vascular smooth muscle cells.

Adrenergic alpha-Agonists↗