Advances in the role of natural products in human gene expression.

Natural products (NPs), especially those from traditional herbal medicines, can evidently modulate human gene expression at multiple levels, leading to a wide diversity of bioactivities. Although numerous bio-functions of NPs for human body have been found, there is little understanding about how NPs achieve it, as less attention was drawn to the definite mechnism by which NPs regulate gene expression. Furthermore, based on the rapidly advancing knowledge of mechanisms for gene regulation in recent years, newly-understood mechanisms, such as post-transcriptional regulation, are found to be involved in NP-elicited bio-effects, providing a new perspective on understanding the role of NPs in gene expression. Therefore, in the current review, we summarize the function of NPs in gene expression from the perspectives of transcriptional, post-transcriptional, and post-translational regulation, which will reinforce the understanding of NP-induced effects in gene expression and facilitate the exploration of more NPs with potential therapeutic effects.

Prevalence and molecular characterization of Trichomonas gallinae from domestic pigeons in Beijing, China.

Trichomonas gallinae is a globally distributed protozoan parasite, mainly affect the upper avian digestive tract and can bring huge economic losses to pigeon industry. The objective of the present study was to determine the prevalence and genotypes of T. gallinae in Beijing, China. A total of 569 samples of throat swabs of pigeon were collected from pigeon farms in Shunyi District, Fangshan District, Daxing District and Miyun District of Beijing. The overall prevalence was 28.30%. The significant difference in infection rates was not observed between regions, but was found between age groups. The highest prevalence was nestling pigeons (33.16%), followed by adolescent pigeons (30.05%) and breeding pigeons (20.59%). Moreover, genotype A and B of T. gallinae were identified by sequencing the ITS1/5.8S/ITS2 regions and phylogenetic analysis. To our knowledge, this is the first report to display the prevalence and genotype of T. gallinae from Beijing, China.

Patterns of polymorphism and divergence in the VP1 gene of enterovirus 71 circulating in the Asia-Pacific region between 1994 and 2013.

Enterovirus 71 has been implicated in several outbreaks of hand, foot and mouth disease in the Asia-Pacific region. The present study aimed to achieve comprehensive evolutionary dynamic aspects of EV71 during 1994-2013, based on phylogenetic analyses of the VP1 sequences. The results indicated that 4 genotypes, namely C4, C1, C2 and B4 are the predominant strains, especially in Southeast Asian countries. No common ancestor was shared in different countries. Fourteen sites of substitutions were detected in the VP1 gene sequences; including the most common sites related to neutralization at position V249I [47.1% (189/401)] and A289T [42.6% (171/401)]. However, the sites Q22H and Q22R associated with increased virulence were recognized only in 13.7% (55/401) and 18% (72/401), respectively. None of the above mutations seemed to become fixed because the ratio of Ka/Ks was greater than 1.0. Mutations K43E, A58T, S184T, and T240S could possibly change the spatial structure. Two mutations, G145E and T240S, could obviously affect the hydrophobicity of VP1 and thus alter the EV71 immunoreactivity. In conclusion, the VP1 gene of EV71 strains circulating in the Asia-Pacific region during 1994-2013, showed polymorphisms and divergence with very slow evolution rate, which may be one of the reasons for periodic outbreaks in this area.

Pandemic influenza A(H1N1) 2009 virus in pregnancy.

Two hundred fourteen abstracts and 87 full texts regarding pregnant women infected with pandemic influenza A(H1N1) 2009 virus were systematically reviewed by using a PubMed search and assessing pandemic, clinical, laboratory test, vaccine, and control experiences. Both policy and health education were excluded. This review counted the total number of pregnant cases from different countries and analyzed their epidemic features, including trimester distribution, morbidity, hospitalization, intensive care unit admissions, maternal mortality, underlying diseases, complications, high-risk factors for death, pregnancy outcome, and clinical symptoms compared with the previous pandemic seasonal influenza A/H1N1 as compared with the general population. Early identification and treatment were the most important factors in different countries and areas examined. The vaccine and antiviral drugs that have been the most efficient means to control the novel virus appear to be safe but require more extensive study. In the future, the focus should be placed on understanding vertical transmission and the severe mechanisms.

[Development of an IMS-qPCR method for detection of Cryptosporidium parvum in water].

OBJECTIVE: To develop a detection method for Cryptosporidium parvum oocysts from water samples, which combined immunomagnetic separation (IMS) with Taqman real-time PCR (qPCR). METHODS: Conditions of separation and enrichment of IMS method by using specific streptavidin magnetic beads coated with monoclonal antibodies Cp23 directed against C. parvum oocysts were optimized. Special primers of PCR and Taqman probes were designed referring to the 18S rDNA gene of C. parvum (GenBank Accession No. AB513881.1). The conserved genes were amplified from genomic DNA of C.parvum, and then cloned into Peasy-T1 vector. Tenfold dilutions of positive plasmids (10(4)-10(8) copy/microl) were used to construct a standard curves by Taqman qPCR. The specificity of the assay was determined using genomic DNA of C. baileyi, Toxoplasma gondii, C. canis and Escherichia coli. The sensitivity of this assay was evaluated by analyzing 10-fold serially dilutions of plasmids ranging from 10(0) to 10(8) copy/microl. Both IMS-qPCR assay and indirect immunofluorescent-antibody assay (IFA) were applied to detect 50 water samples collected from the dairy cattle farms in Hebei. RESULTS: The optimal incubation concentration and time of antibody Cp23 were 20 ng/ml and 30 min, respectively, and the catching time was 30 min, the recovery rate was more than 95%. PCR product was 272 bp, and identified by restriction enzyme digestion and nucleotide sequencing. There was a good linear relationship between the standard plasmids and Ct value (correlation r2 = 0.996 1) of the Taqman qPCR. No cross-reactivity was observed with C. baileyi, T. gondii, C. canis and E. coli. The sensitivity of C. parvum-specific assay was 10 copy/microl. Compared with IFA as golden standard method, the specificity and sensitivity of IMS-qPCR for 50 water samples was 100%(18/18) and 93.8% (30/32), respectively. CONCLUSION: The IMS-qPCR assay can be used to specifically detect C. parvum oocysts in water samples.

[Preparation and identification of monoclonal antibody against sporozoites of Eimeria acervulina].

OBJECTIVE: To establish hybridoma cell lines against sporozoites of Eimeria acervulina. METHODS: BALB/c mice were immunized with purified sporozoites of E. acervulina. Hybridoma cell lines were set up by using hybridoma technique, and monoclonal antibodies were prepared. The monoclonal antibody was identified by determining their cross reactivity, relative affinity, immunoglobulin class or subclass with enzyme linked immunosorbent assay (ELISA). RESULTS: Four hybridoma cell lines stably secreting McAbs against sporozoites were obtained: Easp-3G3 and Easp-5G10 belonging to IgG1, Easp-3H6 belonging to IgG2b, Easp-5H4 belonging to IgG2a. All four McAbs bound with E. acervulina sporozoite protein, but the Easp-5H4 McAb showed cross reactivity with E. tenellum sporozoite protein. Different antigenic epitopes were recognized by Easp-3G3 or Easp-5G10 and Easp-3H6 or Easp-5H4. CONCLUSION: Three of the four produced monoclonal antibodies show high specificity and affinity to the Eimeria acervulina sporozoites.