Ideal methods for detecting pathogens should be sensitive, specific, rapid, cost-effective and instrument-free. Conventional nucleic acid pathogen detection strategies, mostly PCR-based techniques, have various limitations, such as expensive equipment, reagents and skilled performance. Recently, CRISPR/Cas-based methods have burst onto the scene, with the potential to power the pathogen detection field. Here we introduce these unique methods and discuss its hurdles and promises.
ObjectiveTo assess the prevalence of HIV infection and characteristically risk of factors which associated with HIV infection among MSM in Harbin, China.MethodsA face-to-face questionnaire interview was conducted among 463 Men Who Have Sex with Men (MSM) who were recruited by the snowball sampling in Harbin from April, 2011 to July, 2011. The questionnaire mainly included demographics, AIDS knowledge, homosexual behavior and the status of intervention in MSM. Blood specimens were obtained and tested for the diagnoses of HIV, syphilis and hepatitis C virus (HCV). Associations between above exposed factors and HIV infection were analyzed using a univariate analysis and forward stepwise logistic regression.ResultsThe prevalence of HIV and syphilis was 9.5 and 14.3%. The awareness rate of AIDS was 86.8%. The rate of unprotected sexual behavior was 57.6% of MSM during the past 6 months. The univariate analysis identified that the age (age≥35 years old), cohabitation, more than 10 years of homosexual behavior and more than 10 homosexual partners were risk factors which associated with the HIV infection, and that protected sex during the past 6 months was a protective factor for the HIV infection. The multivariate analysis identified that the duration of homosexual behavior and commercial sexual behavior were independent risk factors which associated with the HIV infection, and the protected sex during the past 6 months was a protective factor for the HIV infection.ConclusionThe prevalence of HIV among MSM in Harbin has been rapidly increasing in the past few years. Targeted, tailored, and comprehensive interventions are urgently needed to prevent the HIV infection from MSM.
Fifteen strains of mAb specific for HA of the A/Hong Kong/482/97 (H5N1) influenza virus were generated. The HA antigenic sites of the human A/Hong Kong/482/97 (H5N1) influenza virus were defined by using yeast cell surface-displaying system and anti-H5 HA mAb. Evolution analysis of H5 HA identified residues that exhibit diversifying selection in the antigenic sites and demonstrated surprising differences between residue variation of H5 HA and H3 HA. A conserved neutralizing epitope in the H5 HA protein recognized by mAb H5M9 was found using viruses isolated from [1997][1998][1999][2000][2001][2002][2003][2004][2005][2006]. Seven single amino acid substitutions were introduced into the HA antigenic sites, respectively, and the alteration of antigenicity was assessed. The structure obtained by homology-modeling and molecular dynamic methods showed that a subtle substitution at residue 124 propagates throughout its nearby loop (152)(153)(154)(155)(156)(157)(158)(159). We discuss how the structural changes caused by point mutation might explain the altered antigenicity of the HA protein. The results demonstrate the existence of immunodominant positions in the H5 HA protein, alteration of these residues might improve the immunogenicity of vaccine strains.Key words: Antigenic sites . Evolution analysis . HA . Immunodominant positions IntroductionIn 1997, an H5N1 influenza virus crossed the species barrier to directly transmit from birds to humans in Hong Kong and caused 18 cases of illness including six deaths [1]. New genotypes of the H5N1 virus continued to circulate and occasionally caused severe human disease in Asia [2][3][4]. A lack of protective immunity in the human population against the H5 influenza virus subtype presents a significant risk of an influenza pandemic.Antigenic drift of the influenza virus is caused by the accumulation of mutations in the antigenic regions of HA. Research on influenza virus antigenic drift has mainly been based on the analysis of the human H3N2 subtype [5,6]. The HA protein of all influenza viruses consists of two chains, HA1 and HA2. The HA1 3498mutates more frequently than HA2 and undergoes strong Darwinian selection for novel variants [7]. Using natural and laboratory-selected antigenic variants, five antigenic domains (sites A-E) were revealed in the H3 subtype HA molecule [8]. Of the 329 amino acids in HA1, 131 lie in or near to the five overlapping antigenic sites [5]. Codon usage at the H3 HA epitopic residues are biased toward diversification relative to the nonepitopic residues [7]. In other words, codon biases in the epitopic residues of H3 HA indicate that these residues are under strong selection for substitutional change to escape Ab pressure. Antigenic drift has also been shown to occur with avian influenza viruses, especially those circulating in poultry in the field and in antigenic variant viruses emerging from the H5N1 HPAI virus [9,10]. Therefore, the study of antigenic variation and codon usage at the H5 HA antigenic regions is necessary for the selection o...
Gestational diabetes mellitus (GDM) is a common medical complication in pregnancy, carries adverse health outcomes for both mothers and offspring. However, national data on the prevalence and secular trends of GDM during the past 10 years in the U.S. is lacking. This study included 26,340 ever-pregnant women aged ≥ 18 years from the National Health Interview Survey in 20and 2016. We examined GDM prevalence in 20and 2016. The prevalence of GDM increased from 4.6% in 20to 8.2% in 2016 (P<0.001). non-Hispanic white women showed less increase in the prevalence (2.8%) than non-Hispanic black women (3.8%), Hispanic women (4.1%), and women with other race/ethnicity (8.4%). The prevalence of GDM in non-Hispanic white women was higher than in non-Hispanic black (P=0.01) and women with other race/ethnicity (P=0.01) in 2006; but similar with in non-Hispanic black and lower than in women with other race/ethnicity (p=0.02) in 2016. The prevalence of GDM in non-Hispanic white and Hispanic women was similar in 20and 2016. In addition, the increase of GDM was more evident among women who were overweight, had low income, aged between 45-64 years, and had insufficient physical activity. In conclusion, the prevalence of GDM increased by 3.6% from 20to 2016; and the rise was more marked among non-white, overweight, low income, age 45-64 years, and insufficient activity groups. Disclosure T. Zhou: None. D. Sun: None. X. Li: None. Y. Heianza: None. H. Nisa: None. G. Hu: None. X. Pei: None. X. Shang: None. L. Qi: None.
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