Immunoassay for Capsular Antigen of Bacillus anthracis Enables Rapid Diagnosis in a Rabbit Model of Inhalational Anthrax

Inhalational anthrax is a serious biothreat. Effective antibiotic treatment of inhalational anthrax requires early diagnosis; the further the disease has progressed, the less the likelihood for cure. Current means for diagnosis such as blood culture require several days to a result and require advanced laboratory infrastructure. An alternative approach to diagnosis is detection of a Bacillus anthracis antigen that is shed into blood and can be detected by rapid immunoassay. The goal of the study was to evaluate detection of poly-γ-D-glutamic acid (PGA), the capsular antigen of B. anthracis, as a biomarker surrogate for blood culture in a rabbit model of inhalational anthrax. The mean time to a positive blood culture was 26 ± 5.7 h (mean ± standard deviation), whereas the mean time to a positive ELISA was 22 ± 4.2 h; P = 0.005 in comparison with blood culture. A lateral flow immunoassay was constructed for detection of PGA in plasma at concentrations of less than 1 ng PGA/ml. Use of the lateral flow immunoassay for detection of PGA in the rabbit model found that antigen was detected somewhat earlier than the earliest time point at which the blood culture became positive. The low cost, ease of use, and rapid time to result of the lateral flow immunoassay format make an immunoassay for PGA a viable surrogate for blood culture for detection of infection in individuals who have a likelihood of exposure to B. anthracis.     

Isolation via enrichment and characterization of 14 dinucleotide microsatellite loci in one catfish, Glyptosternum maculatum and cross-amplification in other related taxa

A total of 14 novel dinucleotide microsatellite loci were developed using genomic DNA enrichment protocol and characterized for one Glyptosternoid catfish, Glyptosternum maculatum. Polymorphism was explored using 36 individuals from one natural population. The observed number of alleles ranged from 2 to 9. The ranges of observed and expected heterozygosity were 0.0278 to 1 and 0.4319 to 0.8498, respectively and the average of PIC was 0.5754. In addition, successful cross-species amplification of these set of microsatellite markers in the related taxa, Pseudechenneis sulcatus (McClelland) suggested that they would provide a useful tool for the genetic and conservation studies of Sisoridae species.     

The separation of biomolecules using capillary electrochromatography

The unique properties of capillary electrochromatography such as high performance, high selectivity, minimum consumption of both reagents and samples, and good compatibility with mass spectrometry make this technique an attractive one for the analysis of biomolecules including peptides, proteins, carbohydrates, nucleosides and nucleotides. Irreversible adsorption between the biomolecules and the charged packing surface leads to a lack of reproducibility and serious peak tailing, so various approaches have been taken to overcome this and to improve the technique for future challenges.     

Increased HIV Testing among Men Who Have Sex with Men from 2008 to 2012, Nanjing,China

BackgroundHIV testing is the first point of HIV treatment entry for HIV-infected individuals and an avenue to engage persons at risk in prevention. In China, where the prevalence of HIV among men who have sex with men (MSM) has been rising over the last decade, uptake of HIV testing has been low.MethodsWe examined changes in HIV testing in the preceding 12 months through two cross-sectional surveys conducted among MSM in Nanjing, Jiangsu province, China in 2008 and 2012. Respondent-driven sampling (RDS) was used to recruit participants. Questionnaire interviews and venous blood were collected to measure HIV testing, risk behaviors, and prevalence of HIV, syphilis, and HSV-2.ResultsA total of 430 and 589 MSM were surveyed in 2008 and 2012, respectively, with comparable samples in each round with respect to demographic characteristics. HIV testing in the past 12 months increased significantly from 20.1% (95% CI 13.3–26.8) in 2008 to 46.0% (95% CI 39.3–51.4, p < 0.001) in 2012. HIV prevalence was stable, at 6.6% (95% CI 2.5–11.3) in 2008 and 10.1% (95% CI 6.6–13.9, p = 0.240) in 2012, as was syphilis (14.3% in 2008 vs. 9.9% in 2012, p = 0.240). HSV-2 prevalence (18.6% in 2008 vs. 10.2% in 2012, p = 0.040) and self-reported STI in the last year (24.3% in 2008 vs. 14.3% in 2012, p = 0.020) significantly decreased. Changes in reported sexual behaviors were mixed and the profiles of who did and did not test varied between 2008 and 2012.ConclusionsHIV testing uptake more than doubled among MSM in Nanjing from 2008 to 2012 –a period of massive promotion and scale up of testing programs for MSM. However, additional efforts are still needed to further increase the proportion of men being not only tested but also undergoing repeat testing if they engage in continued risk taking behavior.     

Modulation of cellular disulfide-bond formation and the ER redox environment by feedback regulation of Ero1

Introduction of disulfide bonds into proteins entering the secretory pathway is catalyzed by Ero1p, which generates disulfide bonds de novo, and Pdi1p, which transfers disulfides to substrate proteins. A sufficiently oxidizing environment must be maintained in the endoplasmic reticulum (ER) to allow for disulfide formation, but a pool of reduced thiols is needed for isomerization of incorrectly paired disulfides. We have found that hyperoxidation of the ER is prevented by attenuation of Ero1p activity through noncatalytic cysteine pairs. Deregulated Ero1p mutants lacking certain cysteines show increased enzyme activity, a decreased lag phase in kinetic assays, and growth defects in vivo. We hypothesize that noncatalytic cysteine pairs in Ero1p sense the level of potential substrates in the ER and correspondingly modulate Ero1p activity as part of a homeostatic regulatory system governing the thiol-disulfide balance in the ER.     

The Activation of Heat-Shock Protein After Copper(II) and/or Arsenic(III)-Induced Imbalance of Homeostasis,Inflammatory Response in Chicken Rectum

Biological Trace Element Research - Arsenic and copper, two toxic pollutants, are powerful inducers of oxidative stress. Exposure to copper and arsenic can cause intestinal injury in cockerel. This...     

Feasibility of Recruiting a Diverse Sample of Men Who Have Sex with Men: Observation from Nanjing,China

Background

Respondent-driven-sampling (RDS) has well been recognized as a method for sampling from most hard-to-reach populations like commercial sex workers, drug users and men who have sex with men. However the feasibility of this sampling strategy in terms of recruiting a diverse spectrum of these hidden populations has not been understood well yet in developing countries.

Methods

In a cross sectional study in Nanjing city of Jiangsu province of China, 430 MSM were recruited including 9 seeds in 14 weeks of study period using RDS. Information regarding socio-demographic characteristics and sexual risk behavior were collected and testing was done for HIV and syphilis. Duration, completion, participant characteristics and the equilibrium of key factors were used for assessing feasibility of RDS. Homophily of key variables, socio-demographic distribution and social network size were used as the indicators of diversity.

Results

In the study sample, adjusted HIV and syphilis prevalence were 6.6% and 14.6% respectively. Majority (96.3%) of the participants were recruited by members of their own social network. Although there was a tendency for recruitment within the same self-identified group (homosexuals recruited 60.0% homosexuals), considerable cross-group recruitment (bisexuals recruited 52.3% homosexuals) was also seen. Homophily of the self-identified sexual orientations was 0.111 for homosexuals. Upon completion of the recruitment process, participant characteristics and the equilibrium of key factors indicated that RDS was feasible for sampling MSM in Nanjing. Participants recruited by RDS were found to be diverse after assessing the homophily of key variables in successive waves of recruitment, the proportion of characteristics after reaching equilibrium and the social network size. The observed design effects were nearly the same or even better than the theoretical design effect of 2.

Conclusion

RDS was found to be an efficient and feasible sampling method for recruiting a diverse sample of MSM in a reasonable time.