Molecular characterization and biofilm formation ability of Enterococcus faecium and Enterococcus faecalis bloodstream isolates from a Chinese tertiary hospital in Beijing.

To investigate the molecular characteristics and biofilm-forming ability of 116 Enterococcus faecium (Efm) and 72 Enterococcus faecalis (Efs) isolates obtained from patients with bloodstream infections (BSI) at a Chinese hospital between July 2011 and March 2018. The presence of glycopeptide resistance genes and five virulence genes (esp, gelE, asa1, hyl, and cylA) was screened using two multiplex PCR. MLST was used to assess the clonality. Crystal violet staining was used to detect biofilms. Vancomycin resistance was detected in 30.1% of Efm and 2.8% of Efs isolates, respectively. All VRE strains carried the vanA gene. The esp, gelE, asa1, and cylA genes in 72 Efs strains were detected at 62.5%, 84.7%, 84.7%, and 69.4%, respectively. Among the 116 Efm isolates, 74.1% and 25.8% carried esp and hyl, respectively. The esp gene was significantly associated with vancomycin-resistant Efm (VREfm) compared to vancomycin-susceptible Efm (VSEfm). In total, 91.7% of Efs and 20.0% of Efm produced biofilms. Twenty-six STs were identified among the 72 Efs isolates, with ST4 (29.2%) being the predominant. In total, 116 Efm strains were grouped into 26 STs, with ST78 (46.6%) being the predominant. Both VREfm (41.7%) and VSEfm (48.8%) were dominant in ST78. There is no clear evidence suggesting that some STs are associated with vancomycin resistance or biofilm formation. Both Efm and Efs BSI isolates showed a polyclonal pattern with a dominant clone and many unique types, implying the coexistence of clonal dissemination and an influx of new clones. The horizontal transmission of resistance genes may play a more important role in VREfm prevalence than clonal expansion.

Icarisid II rescues cognitive dysfunction via activation of Wnt/ß-catenin signaling pathway promoting hippocampal neurogenesis in APP/PS1 transgenic mice.

Restoring the compromised neurogenesis has been served as a potential strategy to rescue cognitive dysfunction of Alzheimer's disease (AD). In this study, we explored whether icarisid II (ICS II), a natural product possessing powerful neuroprotection, could recover the neurogenesis dysfunction of APP/PS1 mice, and investigated its underlying mechanisms. Our results showed that oral administration of ICS II could alleviate cognitive injuries of APP/PS1 mice, promote hippocampal neurogenesis, as well as stimulate Wnt/ß-catenin signal pathway confirmed by upregulated Wnt-3a, phosphorylated glycogen synthase kinase-3ß (p-GSK-3ß), and ß-catenin. ICS II also depressed mitochondrial fission evidenced by upregulated Mitofusin 1 (Mfn 1) and Mitofusin 2 (Mfn 2), and downregulated mitochondrial fission 1 protein (Fis 1), mitochondrial fission factor (Mff), and phosphorylated dynamin-related protein 1 (p-Drp 1). However, these effects of ICS II were blunted by XAV-939, an inhibitor of Wnt/ß-catenin signaling pathway. In summary, our findings revealed that ICS II could improve neurogenesis and inhibit mitochondrial fission via activation of the Wnt/ß-catenin signaling pathway, which contributed to cognitive function restoration of APP/PS1 mice. This study discovered a novel mechanism involving neurogenesis regulation underlying the therapeutic effects of ICS II against AD.

Icarisid II promotes proliferation and neuronal differentiation of neural stem cells via activating Wnt/ß-catenin signaling pathway.

Adult neurogenesis plays a vital role in maintaining cognitive functions in mammals and human beings. Mobilization of hippocampal neurogenesis has been regarded as a promising therapeutic approach to restore injured neurons in neurodegenerative diseases including Alzheimer's disease (AD). Icarisid II (ICS II), an active ingredient derived from Epimedii Folium, has been reported to exhibit multiple neuroprotective effects. In the present study, we investigated the effects of ICS II on the proliferation and differentiation of neural stem cells (NSCs) and amyloid precusor protein (APP)-overexpressing NSCs (APP-NSCs) in vitro. Our results demonstrated that ICS II dose-dependently suppressed apoptosis and elevated viability of APP-NSCs. ICS II (1 µM) potently promoted proliferation and neuronal differentiation of NSCs and APP-NSCs. ICS II (1 µM) significantly upregulated Wnt-3a expression, increased the phosphorylation of glycogen synthase kinase-3ß and enhanced the nuclear transfer of ß-catenin. Moreover, ICS II also promoted astrocytes to secrete Wnt-3a, which positively modulates Wnt/ß-catenin signaling pathway. These findings demonstrate that ICS II promotes NSCs proliferation and neuronal differentiation partly by activating the Wnt/ß-catenin signaling pathway.

Multifunctional osthole liposomes and brain targeting functionality with potential applications in a mouse model of Alzheimer's disease.

Osthole (Ost) is a coumarin compound and a potential drug for Alzheimer's disease (AD). However, the effectiveness of Ost is limited by solubility, bioavailability, and low permeability of the blood-brain barrier. In this study, we constructed Ost liposomes with modified CXCR4 on the surface (CXCR4-Ost-Lips), and investigated the intracellular distribution of liposomes in APP-SH-SY5Y cells. In addition, the neuroprotective effect of CXCR4-Ost-Lips was examined in vitro and in vivo. The results showed that CXCR4-Ost-Lips increased intracellular uptake by APP-SH-SY5Y cells and exerted a cytoprotective effect in vitro. The results of Ost brain distribution showed that CXCR4-Ost-Lips prolonged the cycle time of mice and increased the accumulation of Ost in the brain. In addition, CXCR4-Ost-Lips enhanced the effect of Ost in relieving AD-related pathologies. These results indicate that CXCR4-modified liposomes are a potential Ost carrier to treat AD.

Osthole Protects Bone Marrow-Derived Neural Stem Cells from Oxidative Damage through PI3K/Akt-1 Pathway.

In recent years, neural stem cell (NSC) transplantation has been widely explored as a treatment for neurodegenerative diseases. NSCs are special cells that have some capacity for self-renewal and the potential to differentiate into multiple cell types. However, the inflammatory environment of diseased tissue is not conducive to the survival of transplanted cells. Osthole (Ost) is a principal bioactive component of Fructus Cnidii, Radix Angelicae Pubescentis and other traditional Chinese medicines. Ost has a wide range of pharmacological activities, such as anti-inflammation, immunomodulation, and neuroprotection. In the present study, we assessed the protective effects of Ost on bone marrow-derived-NSCs (BM-NSCs) against injury induced by hydrogen peroxide (H2O2). BM-NSCs were pre-treated with different doses of Ost and treated with H2O2. The cell counting kit-8 (CCK-8) method and lactate dehydrogenase (LDH) leakage assay were used to determine cell viability. Using the TUNEL assay and RT-PCR, we evaluated the effect of Ost on cell apoptosis. The results showed that Ost had protective effects against H2O2-induced cell damage, and the number of apoptotic cells was significantly decreased in the Ost pre-treated groups compared to the H2O2 group. The expression ratio of Bax/Bcl-2 mRNA was also decreased. Furthermore, western blotting was used to analyze levels of proteins related to PI3K/Akt-1 signaling pathway, and results indicated that ost can increase p-Akt and PI3K. Our findings suggested that Ost protects BM-NSCs against oxidative stress injury, and it can be used to improve the inflammatory environment of neurodegenerative diseases so and promote the survival rate of transplanted NSCs.

Osthole Enhances the Therapeutic Efficiency of Stem Cell Transplantation in Neuroendoscopy Caused Traumatic Brain Injury.

Neuroendoscopy processes can cause severe traumatic brain injury. Existing therapeutic methods, such as neural stem cell transplantation and osthole have not been proven effective. Therefore, there is an emerging need on the development of new techniques for the treatment of brain injuries. In this study we propose to combine the above stem cell based methods and then evaluate the efficiency and accuracy of the new method. Mice were randomly divided into four groups: group 1 (brain injury alone); group 2 (osthole); group 3 (stem cell transplantation); and group 4 (osthole combined with stem cell transplantation). We carried out water maze task to exam spatial memory. Immunocytochemistry was used to test the inflammatory condition of each group, and the differentiation of stem cells. To evaluate the condition of the damaged blood brain barrier restore, we detect the Evans blue (EB) extravasation across the blood brain barrier. The result shows that osthole and stem cell transplantation combined therapeutic method has a potent effect on improving the spatial memory. This combined method was more effective on inhibiting inflammation and preventing neuronal degeneration than the single treated ones. In addition, there was a distinct decline of EB extravasation in the combined treatment groups, which was not observed in single treatment groups. Most importantly, the combined usage of osthole and stem cell transplantation provide a better treatment for the traumatic brain injury caused by neuroendoscopy. The collective evidence indicates osthole combined with neural stem cell transplantation is superior than either method alone for the treatment of traumatic brain injury caused by neuroendoscopy.

CXCR4 receptor overexpression in mesenchymal stem cells facilitates treatment of acute lung injury in rats.

Novel therapeutic regimens for tissue renewal incorporate mesenchymal stem cells (MSCs) as they differentiate into a variety of cell types and are a stem cell type that is easy to harvest and to expand in vitro. However, surface chemokine receptors, such as CXCR4, which are involved in the mobilization of MSCs, are expressed only on the surface of a small proportion of MSCs, and the lack of CXCR4 expression may underlie the low efficiency of homing of MSCs toward tissue damage, which results in a poor curative effect. Here, a rat CXCR4 expressing lentiviral vector was constructed and introduced into MSCs freshly prepared from rat bone marrow. The influence of CXCR4 expression on migration, proliferation, differentiation, and paracrine effects of MSCs was examined in vitro. The in vivo properties of CXCR4-MSCs were also investigated in a model of acute lung injury in rats induced by lipopolysaccharide. Expression of CXCR4 in MSCs significantly enhanced the chemotactic and paracrine characteristics of the cells in vitro but did not affect self-renewal or differentiation into alveolar and vascular endothelial cells. In vivo, CXCR4 improved MSC homing and colonization of damaged lung tissue, and furthermore, the transplanted CXCR4-MSCs suppressed the development of acute lung injury in part by modulating levels of inflammatory molecules and the neutrophil count. These results indicated that efficient mobilization of MSCs to sites of tissue injury may be due to CXCR4, and therefore, increased expression of CXCR4 may improve their therapeutic potential in the treatment of diseases where tissue damage develops.

A Real-Time PCR Assay Based on 5.8S rRNA Gene (5.8S rDNA) for Rapid Detection of Candida from Whole Blood Samples.

The prevalence of Candida in bloodstream infections (BSIs) has increased. To date, the identification of Candida in BSIs still mainly relies on blood culture and serological tests, but they have various limitations. Therefore, a real-time PCR assay for the detection of Candida from whole blood is presented. The unique primers/probe system was designed on 5.8S rRNA gene (5.8S rDNA) of Candida genus. The analytical sensitivity was determined by numbers of positive PCRs in 12 repetitions. At the concentration of 10(1) CFU/ml blood, positive PCR rates of 100 % were obtained for C. albicans, C. parapsilosis, C. tropicalis, and C. krusei. The detection rate for C. glabrata was 75 % at 10(1) CFU/ml blood. The reaction specificity was 100 % when evaluating the assay using DNA samples from clinical isolates and human blood. The maximum CVs of intra-assay and inter-assay for the detection limit were 1.22 and 2.22 %, respectively. To assess the clinical applicability, 328 blood samples from 82 patients were prospectively tested and real-time PCR results were compared with results from blood culture. Diagnostic sensitivity of the PCR was 100 % using as gold standard blood culture, and specificity was 98.4 %. Our data suggest that the developed assay can be used in clinical laboratories as an accurate and rapid screening test for the Candida from whole blood. Although further evaluation is warranted, our assay holds promise for earlier diagnosis of candidemia.

Transfer of the IL-37b gene elicits anti-tumor responses in mice bearing 4T1 breast cancer.

AIM: IL-37b has shown anti-cancer activities in addition to its anti-inflammatory properties. In this study, we investigated the effects of IL-37b on breast carcinoma growth in mice and to determine the involvement of T cell activation in the effects. METHODS: IL-37b gene was transferred into mouse breast carcinoma cell line 4T1 (4T1-IL37b cells), the expression of secretory IL-37b by the cells was detected, and the effects of IL-37b expression on the cell proliferation in vitro was evaluated. After injection of 4T1 cells or 4T1-IL37b cells into immunocompetent BALB/c mice, immunodeficient BALB/c nude mice and NOD-SCID mice, the tumor growth and survival rate were measured. The proliferation of T cells in vitro was also detected. RESULTS: IL-37b was detected in the supernatants of 4T1-IL37b cells with a concentration of 12.02 ± 0.875 ng/mL. IL-37b expression did not affect 4T1 cell proliferation in vitro. BALB/c mice inoculated with 4T1-IL37b cells showed significant retardation of tumor growth. BALB/c mice inoculated with both 4T1 cells and mitomycin C-treated 4T1-IL37b cells also showed significant retardation of tumor growth. But the anti-cancer activity of IL-37b was abrogated in BALB/c nude mice and NOD-SCID mice inoculated with 4T1-IL37b cells. Recombinant IL-37b slightly promoted CD4(+) T cell proliferation without affecting CD8(+) T cell proliferation. CONCLUSION: IL-37b exerts anti-4T1 breast carcinoma effects in vivo by modulating the tumor microenvironment and influencing T cell activation.

[Difference in effect between asthma-based mouse model and Stemona tuberosa extracts].

In this study, OVA-induced asthma mice was taken as the model, and orally administered with different concentration of ethanol extracts of crude and processed Stemona tuberosa, in order to determine the cytokine level released from Th1 and Th2 in splenocytes. RT-PCR was carried out to determine the genetic expression of T-bet/GATA-3 in lung, and compare the differentiation between ethanol extracts of crude and processed S. tuberosa in therapeutic effect on asthma in mice. According to the results, compared with the crude samples, processed samples significantly increased the levels of inflammatory factor INF-gamma (P < 0.05) and decreased IL-5 (P < 0.05) in splenocytes. According to the RT-PCR results, the administration of processed samples could increase the ratio of T-bet/GATA-3 (P < 0.05). The experiment showed that ethanol extracts of both crude and processed S. tuberosa could treat asthma by regulating Th1/Th2 ratio, but processed samples showed more notable effect. This indicated that crude and processed S. tuberosa had significant pharmacological difference. Therefore, it was more rational to apply processed S. tuberosa in clinical treatment of asthma and chronic cough, which layed a foundation for further revealing the processing mechanism of S. tuberosa.

A type-specific nested PCR assay established and applied for investigation of HBV genotype and subgenotype in Chinese patients with chronic HBV infection.

BACKGROUND: Many studies have suggested that hepatitis B virus (HBV) genotypes show not only geographical distribution and race specificity, but also are associated with disease progression and response to interferon treatment. The objective of this study was to develop a nested polymerase chain reaction (nPCR) assay for genotypes A-D and subgenotypes B1, B2, C1 and C2 of hepatitis B virus (HBV) and to investigate the distribution characteristics of HBV genotypes/subgenotype in China. METHODS: After redesigning the primers and optimizing the reaction conditions using common Taq polymerase, the sensitivity, specificity and reproducibility of the method were evaluated using plasmids and serum samples. In total, 642 serum samples from patients with chronic HBV infection were applied to investigate the distribution of HBV genotype and subgenotype in China. RESULTS: The genotype and subgenotype could be identified when the HBV DNA load of a sample was ≥10(2.3) IU/mL. For the 639 successfully genotyped samples, the sequencing results of 130 randomly selected samples (20.3%, 130/639) were consistent with those of the nPCR method. The present study showed that HBV genotype B (11.2%, 72/642), C (68.2%, 438/642) and D (7.2%, 46/642) were circulating in China, while genotype C was the dominant strain except for western region where genotype D was the prevalent strain. The main subgenotypes of genotypes B and C were B2 (87.5%, 63/72) and C2 (92.9%, 407/438), respectively. CONCLUSIONS: The low-cost nPCR method would be a useful tool for clinical and epidemiological investigation in the regions where genotypes A-D are predominant.

Jujuboside A inhibits oxidative stress damage and enhances immunomodulatory capacity of human umbilical cord mesenchymal stem cells through up-regulating IDO expression.

Impaired immunomodulatory capacity and oxidative stress are the key factors limiting the effectiveness of mesenchymal stem cell transplantation therapy. The present study was aimed to investigate the effects of jujuboside A (JuA) on the protective effect and immunomodulatory capacity of human umbilical cord mesenchymal stem cells (hUC-MSCs). Hydrogen peroxide was used to establish an oxidative damage model of hUC-MSCs, while PBMCs isolated from rats were used to evaluate the effect of JuA pre-treatment on the immunomodulatory capacity of hUC-MSCs. Furthermore, Hoechst 33258 staining, lactate dehydrogenase test, measurement of malondialdehyde, Western blot, high-performance liquid chromatography; and flow cytometry were performed. Our results indicated that JuA (25 µmol·L-1) promoted the proliferation of hUC-MSCs, but did not affect the differentiating capability of these cells. JuA pre-treatment inhibited apoptosis, prevented oxidative damage, and up-regulated the protein expression of nuclear factor-erythroid factor 2-related factor 2 and heme oxygenase 1 in hUC-MSCs in which oxidative stress was induced with H2O2. In addition, JuA pre-treatment enhanced the inhibitory effect of hUC-MSCs against abnormally activated PBMCs, which was related to stimulation of the expression and activity of indoleamine 2,3-dioxygenase. In conclusion, our results demonstrate that JuA pre-treatment can enhance the survival and immunomodulatory ability through pathways related to oxidative stress, providing a new option for the improvement of hUC-MSCs in the clinical setting.

Jujuboside a promotes proliferation and neuronal differentiation of APPswe-overexpressing neural stem cells by activating Wnt/ß-catenin signaling pathway.

Mobilization of hippocampal neurogenesis has been considered as a potential strategy for the treatment of neurodegenerative diseases, including Alzheimer's disease (AD). In present study, we evaluated both the neuroprotective effects and the effects on the proliferation and differentiation of APP-overexpressing neural stem cells (APP-NSCs) by Jujuboside A (JuA) in vitro. Our results demonstrated that JuA (50 µM) decreased apoptosis and suppressed oxidative stress damage of APP-NSCs. JuA (50 µM) upregulated the secretion of brain-derived neurotrophic factor and promoted the proliferation and neuronal differentiation of APP-NSCs. Moreover, JuA (50 µM) upregulated Wnt-3a and ß-catenin protein expression, and enhanced the expression of downstream genes Ccnd1, Neurod1 and Prox1. However, XAV-939, an inhibitor of the Wnt/ß-catenin signaling pathway, inhibited these positive effects of JuA. Taken together, these findings suggest that JuA promote proliferation and neuronal differentiation of APP-NSCs partly by activating the Wnt/ß-catenin signaling pathway. We hope that this study will provide a viable strategy for the treatment of AD.

Active constituent of Polygala tenuifolia attenuates cognitive deficits by rescuing hippocampal neurogenesis in APP/PS1 transgenic mice.

BACKGROUND: Alzheimer's disease (AD) is the most common dementia worldwide, and there is still no satisfactory drug or therapeutic strategy. Polygala tenuifolia is a traditional Chinese medicine with multiple neuroprotective effects. In present study, we investigated the effects of three active constituents [3,6'-disinapoyl sucrose (DISS), onjisaponin B (OB) and tenuifolin (TEN)] of Polygala tenuifolia (PT) on the proliferation and differentiation of neural stem cells (NSCs) to identify the potential active constituent of PT promoting hippocampal neurogenesis. METHODS: NSCs were isolated from hippocampi of newborn C57BL/6 mice, and transfected with mutant amyloid precursor protein (APP) gene to establish an AD cell model (APP-NSCs). 3-(4,5- Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays were performed, and the proliferation and differentiation of NSCs were assessed by neurosphere formation assay, 5-bromo-2'-deoxyuridine (BrdU) incorporation assay and immunofluorescence (IF) staining analysis. APP/PS1 transgenic mice were administrated with the potential active constituent DISS for 4 weeks. Morris water maze (MWM), Nissl staining assay and IF staining assays were carried out to evaluate the cognitive function, neural damages and hippocampal neurogenesis, respectively. RESULTS: DISS exerted the optimal ability to strengthen APP-NSCs proliferation and neuronal differentiation, followed by OB and TEN. Furthermore, DISS treatment for 4 weeks strikingly rescued the cognitive deficits, neuronal injures, and neurogenesis disorder in adult APP/PS1 transgenic mice. CONCLUSIONS: Our findings demonstrated that DISS is the constituent of PT that triggers the most potent increase of hippocampal neurogenesis in our mouse model of AD.

[Drug resistance, genotype, and serotype of hepatitis B virus in nucleos(t)ide analogue naive patients with chronic hepatitis B].

OBJECTIVE: To investigate drug resistance, genotype and serotype of hepatitis B virus (HBV) in nucleos(t)ide analogue (NA) naive patients with chronic hepatitis B (CHB). METHODS: Full-length reverse transcriptase region of HBV DNA was amplified by semi-nested polymerase chain reaction from 97 NA-naive CHB patients, and the PCR product was sequenced, and analyzed to screen 11 classical antiviral drug resistance mutation sites and to identify HBV genotypes, subgenotypes and serotypes. RESULTS: Wild-type sequences were found at all of the 11 classical antiviral drug resistance mutation sites from all samples. The patients were infected with either genotype B (36.1%, 35/97) or C (63.9%, 62/97) HBV. The former were all belonged to subgenotype B2 strain; while the latter were divided further into subgenotype C2 (91.9%, 57/62), subgenotype C1 (6.5%, 4/62) and unknown subgenotype (1.6%, 1/62). The 71.9% (23/32) of HBV genotype B patients were born in southern China, while 81.6% (40/49) of HBV genotype C patients were from northern China, showing a clear geographic distribution (Chi-square test = 23.19, Probability value less than 0.01). Of 97 CHB patients, 59 (60.8%) were serotype adr associated with genotype C, while 37 (38.1%) were adw related to genotype B (subgenotype B2) (Chi-square test = 87.83, P less than 0.01). CONCLUSION: The wild-type HBV strains prevail in NA-naive CHB patients, whose HBV genotypes, subgenotypes and serotypes are associated with their places of birth.

Transferrin-Modified Osthole PEGylated Liposomes Travel the Blood-Brain Barrier and Mitigate Alzheimer's Disease-Related Pathology in APP/PS-1 Mice.

INTRODUCTION: Osthole (Ost) is a coumarin compound that strengthens hippocampal neurons and neural stem cells against Aß oligomer-induced neurotoxicity in mice, and is a potential drug for the treatment of Alzheimer's disease (AD). However, the effectiveness of the drug is limited by its solubility and bioavailability, as well as by the low permeability of the blood-brain barrier (BBB). In this study, a kind of transferrin-modified Ost liposomes (Tf-Ost-Lip) was constructed, which could improve the bioavailability and enhance brain targeting. METHODS: Tf-Ost-Lip was prepared by thin-film hydration method. The ability of liposomal formulations to translocate across BBB was investigated using in vitro BBB model. And the protective effect of Tf-Ost-Lip was evaluated in APP-SH-SY5Y cells. In addition, we performed pharmacokinetics study and brain tissue distribution analysis of liposomal formulations in vivo. We also observed the neuroprotective effect of the varying formulations in APP/PS-1 mice. RESULTS: In vitro studies reveal that Tf-Ost-Lip could increase the intracellular uptake of hCMEC/D3 cells and APP-SH-SY5Y cells, and increase the drug concentration across the BBB. Additionally, Tf-Ost-Lip was found to exert a protective effect on APP-SH-SY5Y cells. In vivo studies of pharmacokinetics and the Ost distribution in brain tissue indicate that Tf-Ost-Lip prolonged the cycle time in mice and increased the accumulation of Ost in the brain. Furthermore, Tf-Ost-Lip was also found to enhance the effect of Ost on the alleviation of Alzheimer's disease-related pathology. CONCLUSION: Transferrin-modified liposomes for delivery of Ost has great potential for AD treatment.

Novel HBV recombinants between genotypes B and C in 3'-terminal reverse transcriptase (RT) sequences are associated with enhanced viral DNA load, higher RT point mutation rates and place of birth among Chinese patients.

As one of the major global public health concerns, hepatitis B virus (HBV) can be divided into at least eight genotypes, which may be related to disease severity and treatment response. We previously demonstrated that genotypes B and C HBV, with distinct geographical distribution in China, had divergent genotype-dependent amino acid polymorphisms and variations in reverse transcriptase (RT) gene region, a target of antiviral therapy using nucleos(t)ide analogues. Recently recombination between HBV genotypes B and C was reported to occur in the RT region. However, their frequency and clinical significance is poorly understood. Here full-length HBV RT sequences from 201 Chinese chronic hepatitis B (CHB) patients were amplified and sequenced, among which 31.34% (63/201) were genotype B whereas 68.66% (138/201) genotype C. Although no intergenotypic recombination was detected among C-genotype HBV, 38.10% (24/63) of B-genotype HBV had recombination with genotype C in the 3'-terminal RT sequences. The patients with B/C intergenotypic recombinants had significantly (P<0.05) higher serum HBV DNA level than the "pure" B-genotype cohort did. Moreover, the B/C intergenotypic recombinants were prone to more substitutions at several specific residues in the RT region than genotype B or C. Besides, unlike their parental genotypes, the recombinant HBV appeared to display an altered geographic distribution feature in China. Our findings provide novel insight into the virological, clinical and epidemiological features of new HBV B/C intergenotypic recombinants at the 3' end of RT sequences among Chinese CHB patients. The highly complex genetic background of the novel recombinant HBV carrying new mutations affecting RT protein may contribute to an enhanced heterogeneity in treatment response or prognosis among CHB patients.

[Inhibitory effect of Adp53 and F56 on growth and metastasis of transplantation of the breast tumor in mice].

OBJECTIVE: To investigate the effects of Adp53 and F56 on the growth and lung metastasis of breast cancer. METHODS: The BICR-H1 cells were inoculated into the mammary fatty pad of BALB/C nude mice and NOD/SCID mice to establish breast cancer model. Then the nude mice with xenograft tumor were randomized into group Adp53+F56, Adp53, F56 and control. The NOD/SCID mice with xenograft tumor were randomized into group Adp53+F56, Adp53, F56, Adlacz and control. They were treated for 3 weeks according to the plan, diversity of the volume and histopathology of xenograft tumor of nude mice was observed and the expressions of p53 and VEGF gene, and microvessel density (MVD) were detected by immunohistochemistry. Lung metastasis of breast cancer in NOD/SCID mice was observed. RESULTS: (1) Intratumoral injections of Adp53, F56, and their combination resulted in an inhibition on the growth of xenograft tumor of BICR-H1 cells. The ultimate relative growth volumes of groups Adp53+F56, Adp53, F56 and control were 2.47,4.37,4.69 and 12.49 respectively. (2) After treatment, P53 positive rate of group Adp53+F56, Adp53 increased 9.4%, 6.3% than before respectively, but compared with control group, the difference is not significant (P=0.693); VEGF protein of group Adp53+F56, Adp53 and F56 decreased 21.9%, 9.4% and 3.1% than before respectively, but compared with control group, the difference was not significant (P=0.284). Necrosis and decrease of vessel in the tumor and morphological change of endothelium were observed under light microscope in the groups Adp53+F56, Adp53 and F56. MVD estimated by FVIII-RA staining of group Adp53+F56, Adp53 and F56 were 14.50+/-2.54, 16.28+/-3.44 and 18.06+/-7.66, compared with control group(24.93+/-6.53), the difference is significant (P=0.000). (3) The average number of lung metastasis of NOD/SCID mice in group Adp53+F56, Adp53 and F56 were 1.143+/-0.378, 2.750+/-0.886 and 3.375+/-0.518 respectively, lower than Adlacz group(5.000+/-0.816) and control group (5.670+/-0.817) obviously (P=0.000). CONCLUSION: Adp53 combined with F56 can greatly inhibit growth and metastasis of breast cancer in vivo. The mechanism of anti-tumor effects of Adp53 and F56 may be related to the anti-angiogenesis effect on malignant tumor through inhibiting the expression and activity of VEGF.

Osthole Stimulated Neural Stem Cells Differentiation into Neurons in an Alzheimer's Disease Cell Model via Upregulation of MicroRNA-9 and Rescued the Functional Impairment of Hippocampal Neurons in APP/PS1 Transgenic Mice.

Alzheimer's disease (AD) is the most serious neurodegenerative disease worldwide and is characterized by progressive cognitive impairment and multiple neurological changes, including neuronal loss in the brain. However, there are no available drugs to delay or cure this disease. Consequently, neuronal replacement therapy may be a strategy to treat AD. Osthole (Ost), a natural coumarin derivative, crosses the blood-brain barrier and exerts strong neuroprotective effects against AD in vitro and in vivo. Recently, microRNAs (miRNAs) have demonstrated a crucial role in pathological processes of AD, implying that targeting miRNAs could be a therapeutic approach to AD. In the present study, we investigated whether Ost could enhance cell viability and prevent cell death in amyloid precursor protein (APP)-expressing neural stem cells (NSCs) as well as promote APP-expressing NSCs differentiation into more neurons by upregulating microRNA (miR)-9 and inhibiting the Notch signaling pathway in vitro. In addition, Ost treatment in APP/PS1 double transgenic (Tg) mice markedly restored cognitive functions, reduced Aß plague production and rescued functional impairment of hippocampal neurons. The results of the present study provides evidence of the neurogenesis effects and neurobiological mechanisms of Ost against AD, suggesting that Ost is a promising drug for treatment of AD or other neurodegenerative diseases.

Bi-directional regulation of emodin and quercetin on smooth muscle myosin of gizzard.

This study is to reveal the characteristics of bidirectional regulation of emodin (1,3,8-trihydroxy-6-methyl-anthraquinone) and quercetin on gizzard smooth muscle myosin. Our results indicate that: (a) emodin demonstrates stimulatory effects, and quercetin produces inhibitory effects on myosin phosphorylation and Mg(2+)-ATPase activities of Ca(2+)/calmodulin-dependent phosphorylated myosin in a dose-dependent manner; (b) a combination of emodin and quercetin enhances phosphorylation and Mg(2+)-ATPase activities for partially phosphorylated myosin and inhibits those activities for fully phosphorylated myosin; (c) 1-(5-Chloronaphthalene-1-sulfonyl)-1H2-hexahydro-1,4-diazepine inhibits myosin phosphorylation in the presence of emodin and/or quercetin. A combination of emodin and quercetin indicates its potential for modulating gastric-intestinal smooth muscle.