[Distribution patterns of giant panda in Guanyinshan and Foping nature reserves].

By using line transect method, the distribution patterns of giant panda population and its sympatric companion wildlife species in Foping and Guanyinshan nature reserves were investigated in October 2007 and April 2008, and the environmental factors affecting the spatial distribution of giant panda activity were analyzed. The giant panda population and its sympatric companion wildlife species in the two reserves had the similar distribution patterns, and the density and distribution range of giant panda were smaller in Guanyinshan than in Foping. Giant panda had two high-density distribution areas in Foping, but no activity trace in most parts of Guanyinshan.

DNA polymerase beta-dependent long patch base excision repair in living cells.

We examined a role for DNA polymerase beta (Pol beta) in mammalian long patch base excision repair (LP BER). Although a role for Pol beta is well known in single-nucleotide BER, information on this enzyme in the context of LP BER has been limited. To examine the question of Pol beta involvement in LP BER, we made use of nucleotide excision repair-deficient human XPA cells expressing UVDE (XPA-UVDE), which introduces a nick directly 5' to the cyclobutane pyrimidine dimer or 6-4 photoproduct, leaving ends with 3'-OH and 5'-phosphorylated UV lesion.

The degradation and adsorption behaviors of enzyme on poly(butylene succinate) single crystals.

The enzymatic degradation behavior of poly(butylene succinate) (PBS) single crystals with a lipase from Pseudomonas cepacia (lipase PS) is monitored using atomic force microscopy (AFM) in phosphate buffer at pH 6.8 and 40 degrees C. In-situ AFM results show that enzymatic degradation of the single crystal starts from the crystal edges rather than the chain-folded surfaces and the lamellar thickness remains constant during the whole degradation process.

Structural basis of the cross-reactivity of genetically related human anti-HIV-1 mAbs: implications for design of V3-based immunogens.

Human monoclonal antibodies 447-52D and 537-10D, both coded by the VH3 gene and specific for the third variable region (V3) of the HIV-1 gp120, were found to share antigen-binding structural elements including an elongated CDR H3 forming main-chain interactions with the N terminus of the V3 crown. However, water-mediated hydrogen bonds and a unique cation-pi sandwich stacking allow 447-52D to be broadly reactive with V3 containing both the GPGR and GPGQ crown motifs, while the deeper binding pocket and a buried Glu in the binding site of 537-10D limit its reactivity to only V3 containing the GPGR motif. Our results suggest that the design of immunogens for anti-V3 antibodies should avoid the Arg at the V3 crown, as GPGR-containing epitopes appear to select for B cells making antibodies of narrower specificity than V3 that carry Gln at this position.

Cholesterol metabolism and expression of its relevant genes in cultured steatotic hepatocytes.

Objective: To investigate the cholesterol metabolism and mRNA expression of the relevant genes in cholesterol synthesis of the cultured steatotic hepatocytes model.

Methods: A steatotic model of hepatocytes was constructed by adding palmitic acid to the growing L-02 cells. These cells were collected at day 3 and 6, respectively.

ABCB11 gene mutations in Chinese children with progressive intrahepatic cholestasis and low gamma glutamyltransferase.

Background: Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a severe autosomal recessive liver disorder of childhood that can cause cholestasis and progress to end-stage liver disease. ABCB11 gene mutations causing PFIC2 have been reported in some population groups, but not in mainland Chinese.

Aims: To elucidate the existence of and characterize ABCB11 gene mutations in mainland Chinese with progressive intrahepatic cholestasis and low gamma glutamyltransferase (GGT).

Recurrence in oral and pharyngeal cancer is associated with quantitative MGMT promoter methylation.

Background: Biomarkers that predict clinical response, tumor recurrence or patient survival are severely lacking for most cancers, particularly for oral and pharyngeal cancer. This study examines whether gene-promoter methylation of tumor DNA correlates with survival and recurrence rates in a population of patients with oral or pharyngeal cancer.

Methods: The promoter methylation status of the DNA repair gene MGMT and the tumor suppressor genes CDKN2A and RASSF1 were evaluated by methylation-specific PCR in 88 primary oral and pharyngeal tumors and correlated with survival and tumor recurrence.

Different expression of dectin-1 and Toll-like receptor 2 in the lungs of different immune status mice infected with Aspergillus fumigatus.

Background: Invasive pulmonary aspergillosis (IPA) is a severe and frequently fatal disease in patients receiving treatment with immunosuppressive agents such as cyclophosphamide. Aspergillus fumigatus (A. fumigatus) now is a leading cause of IPA.

Changes in modes of hepatitis C infection acquisition and genotypes in southwest China.

Background: The shift in the distribution of HCV genotypes could have a significant impact on practical medical issues.

Objectives: To describe the recent distribution and evolution of HCV genotypes in southwest China.

Study Design: HCV genotypes were determined by nucleotide sequencing of the CE1 regions followed by phylogenic analysis with the published HCV genotype.

[Randomized controlled clinical trials of acupuncture treatment of chronic fatigue syndrome].

Objective: To observe the effect of acupuncture on the fatigue degree in patients with chronic fatigue syndrome (CFS).

Methods: Seventy CFS patients were equally randomized into control and treatment groups according to randomized block design. Acupuncture was applied to Baihui (GV 20), Danzhong (CV 17), Zhongwan (CV 12), etc.

[Effect of Wenyang Yiqi Pingchuan recipe on pathomorphology of lung and its regulation on lung tissue contents of nitric oxide and endothelin-1 in rats with bronchial asthma].

Objective: To observe the effect of Wenyang Yiqi Pingchuan Recipe (WYPR) on the pathomorphology of lung and its regulation on lung tissue contents of nitric oxide (NO) and endothelin-1 (ET-1) in rats with bronchial asthma.

Methods: Sixty SD rats were randomly divided into 6 groups: the normal group, the model group, and the four treated groups treated with high dose WYPR, low dose WYPR, Guilong Kechuanning Capsule and aminophylline, respectively, 10 in each group. Except those in the normal group, all rats of bronchial asthma model were established by egg protein sensitization and provocated by inhalation.

Biomechanical properties of adult-excised porcine trachea for tracheal xenotransplantation.

Background: To investigate and evaluate the biomechanical properties of adult-excised porcine trachea, thereby providing experimental methods and evidence for biomedical engineering of artificial trachea.

Methods: The TY8000 servo-handle tension test machine was used to measure biomechanical indices, such as bending stiffness, radial pedestal, and stress-straining. The residual stress and bursting strength of adult-excised porcine trachea was evaluated.

Influence of auricular plaster therapy on sleeping structure in OSAS patients.

Objective: To evaluate the therapeutic effects of auricular plaster therapy for obstructive sleep apnea syndrome (OSAS) and the influence on sleeping structure.

Methods: 45 OSAS patients were randomly divided into a treatment group of 30 cases and a control group of 15 cases for comparison of the changes in parameters of respiration and sleep at night.

Results: The auricular plaster therapy significantly improved the hypoventilation index, respiratory disturbance index and other respiratory parameters as well as the sleeping parameters such as the time and rate of sleep at stage I and II, and the waking time and rate.

Human monoclonal antibody 2909 binds to pseudovirions expressing trimers but not monomeric HIV-1 envelope proteins.

A human anti-HIV monoclonal antibody (mAb), 2909, selected on the basis of its potent neutralizing activity against HIV-1SF162, recognizes a complex epitope V2/V3 present on intact virions but not on soluble gp120. To confirm the quaternary nature of the epitope, 2909 binding was tested against the pseudovirus SF162 wild type (WT) expressing trimers and/or an SF162 mutant expressing monomeric envelope proteins. The construction of the SF162 mutant was made by an alanine substitution of nine hydrophobic residues in the N-terminal heptad repeat region of gp41 molecules that failed to form trimers on the virus surface.

Evidence for biogenic processes during formation of ferromanganese crusts from the Pacific Ocean: implications of biologically induced mineralization.

Ferromanganese [Fe/Mn] crusts formed on basaltic seamounts, gain considerable economic importance due to their high content of Co, Ni, Cu, Zn and Pt. The deposits are predominantly found in the Pacific Ocean in depths of over 1000m. They are formed in the mixing layer between the upper oxygen-minimum zone and the lower oxygen-rich bottom zone.

Selection pressure from neutralizing antibodies drives sequence evolution during acute infection with hepatitis C virus.

Background & Aims: Despite recent characterization of hepatitis C virus-specific neutralizing antibodies, it is not clear to what extent immune pressure from neutralizing antibodies drives viral sequence evolution in vivo. This lack of understanding is particularly evident in acute infection, the phase when elimination or persistence of viral replication is determined and during which the importance of the humoral immune response has been largely discounted.

Methods: We analyzed envelope glycoprotein sequence evolution and neutralization of sequential autologous hepatitis C virus pseudoparticles in 8 individuals throughout acute infection.

Synthesis, biological activity and tubulin binding poses of 1-deoxy-9-(R)-dihydrotaxane analogs.

1-Deoxy-9alpha-dihydrotaxane analogs 9 and 10 were semi-synthesized from 1-deoxybaccatin VI, isolated from Taxus mairei, and tested for cytotoxic activity. Taxane 9 is 10-fold less cytotoxic than paclitaxel, while 10 is equally active. In the tubulin polymerization assay (ED(50) values), 10 is 4-fold less effective than paclitaxel, but 3-fold superior to 9.

Clinical and pathological characteristics of Alagille syndrome in Chinese children.

Background: Alagille syndrome (AS) is regarded as the most common cause of chronic cholestasis in childhood associated with specific phenotypic features in western countries. This study was undertaken to investigate the significance of AS in Chinese children with chronic cholestasis and to describe its clinical and histological features.

Methods: From October 2004 to January 2007, 157 children who presented with conjugated jaundice from less than 3 months of age were admitted to a tertiary hospital in Shanghai.

[Effects of antiarrhythmic drug use on atrial fibrillation recurrence in atrial fibrillation patients post circumferential pulmonary vein ablation].

Objective: This prospective and randomize-controlled trial was designed to investigate the effects of antiarrhythmic drug use (AADs) on atrial fibrillation (AF) recurrence in atrial fibrillation patients post circumferential pulmonary vein ablation (CAPV).

Methods: Seventy-four consecutive AF patients underwent CAPV (41 paroxysmal and 33 drug refractory AF) were randomly assigned to receive placebo (Group A) or AADs (Group B) for 3 months. Monthly standard electrocardiograms (ECG) and Holter monitoring were performed to assess AF recurrences during 17 - 28 months follow-up.

[Randomized controlled multi-center trial for treatment of varicella in pediatric patients with hydrochloride valacyclovir].

Objective: To evaluate the efficacy and safety of hydrochloride valacyclovir in treatment of varicella in pediatric patients between April 2006 and March 2007.

Methods: A randomized controlled multi-center clinical trial was conducted in 5 pediatric centers, i.e.

Preferential use of the VH5-51 gene segment by the human immune response to code for antibodies against the V3 domain of HIV-1.

Human anti-V3 monoclonal antibodies (mAbs) generated from HIV-1 infected individuals display diversity in the range of their cross-neutralization that may be related to their immunogenetic background. The study of the immunoglobulin (Ig) variable region gene usage of heavy chains have shown a preferential usage of the VH5-51 gene segment which was detected in 35% of 51 human anti-V3 mAbs. In contrast, human mAbs against other envelope regions of HIV-1 (anti-Env), including the CD4-binding domain, the CD4-induced epitope, and gp41 preferentially used the VH1-69 gene segment, and none of them used the VH5-51 gene.

Mechanism of induction and suppression of antiviral immunity directed by virus-derived small RNAs in Drosophila.

The small RNA-directed viral immunity pathway in plants and invertebrates begins with the production by Dicer nuclease of virus-derived siRNAs (viRNAs), which guide specific antiviral silencing by Argonaute protein in an RNA-induced silencing complex (RISC). Molecular identity of the viral RNA precursor of viRNAs remains a matter of debate. Using Flock house virus (FHV) infection of Drosophila as a model, we show that replication of FHV positive-strand RNA genome produces an approximately 400 bp dsRNA from its 5' terminus that serves as the major Dicer-2 substrate.

[The effects of dose of salbutamol and observation time on bronchodilation test].

Objective: To evaluate the effects of different doses of salbutamol and observation times on bronchodilation test.

Methods: Three groups of subjects (30 patients with asthma, 29 patients with COPD, and 30 normal controls) were included in this study. The forced expiratory volume in the first second (FEV1) was evaluated in the positive rates at 15, 20, and 30 min after inhaling 200 microg or 400 microg salbutamol.