T-lymphoid, megakaryocyte, and granulocyte development are sensitive to decreases in CBFbeta dosage

The family of core-binding factors includes the DNA-binding subunits Runx1-3 and their common non-DNA-binding partner CBFbeta. We examined the collective role of core-binding factors in hematopoiesis with a hypomorphic Cbfb allelic series. Reducing CBFbeta levels by 3- or 6-fold caused abnormalities in bone development, megakaryocytes, granulocytes, and T cells. T-cell development was very sensitive to an incremental reduction of CBFbeta levels: mature thymocytes were decreased in number upon a 3-fold reduction in CBFbeta levels, and were virtually absent when CBFbeta levels were 6-fold lower. Partially penetrant consecutive differentiation blocks were found among early T-lineage progenitors within the CD4- CD8- double-negative 1 and downstream double-negative 2 thymocyte subsets. Our data define a critical CBFbeta threshold for normal T-cell development, and situate an essential role for core-binding factors during the earliest stages of T-cell development.     

Improved risk assessment of coronary artery disease by substituting paraoxonase 1 activity for HDL-C: Novel cardiometabolic biomarkers based on HDL functionality

Background and aimsDeveloping laboratory assays to evaluate HDL functions and improve cardiovascular disease (CVD) risk assessment has recently emerged as a challenge. The present study was conducted to help predict the risk of coronary artery disease (CAD) by investigating new cardiometabolic risk factors based on substituting paraoxonase 1 (PON1) as a critical enzyme in the functionality of HDL for that of HDL-C.Methods and resultsThe present study recruited 274 subjects undergoing diagnostic coronary angiography, 92 without significant CAD (non-CAD), and 182 with a severe CAD. The diagnostic accuracy of the new biomarkers in non-CAD versus multi-vessel disease was obtained in descending order of AUC as 0.72 (P < 0.001) for log (TG/PON1), 0.70 (P < 0.001) for nonHDL-C/PON1, and 0.67 (P < 0.001) for LDL-C/PON1. After performing a multivariate adjustment for age, gender, BMI, statin therapy, and diabetes mellitus, the increased odds of CAD remained significant for the new cardiometabolic ratios as independent variables [adjusted OR = 1.47 (1.15–1.88), p = 0.002 for LDL-C/PON1; adjusted OR = 2.15 (1.41–3.5), p = 0.009 for nonHDL-C/PON1; adjusted OR = 5.03 (2.14–13.02), p = 0.004 for log (TG/PON1)]. CAD was diagnosed with an optimal discriminating cutoff of 1.84 for LDL-C/PON1, 2.8 for nonHDL-C/PON1, and 0.48 for log (TG/PON1).ConclusionsTo improve CAD's risk assessment, the PON1 activity was proposed as an alternative to HDL-C in the commonly used atherogenic lipid ratios. Substituting the PON1 activity for the HDL-C concentration can provide an index of the HDL activity. The present study sought to exploit the lipoprotein-related risk factors of CAD from a more effective perspective.     

Comparison of two proliferation assays MTT and ltt in immunodeficient patients

MTT assay is designed for spectrophotometric quantification of cell growth and viability without using the radiactive isotopes. The aim of this study is comparison of LIT and MTT as sensitive poliferation assays in imrnunodeficient patients. 20 immunodeficient and 20 healthy subjects were selected in this study. All of them had normal lymphocytes count, normal CD3 and negative DIR reaction to PPD, DT and candida. The immunodeficient patients regularly suffered from herpes, candida and staph abscess. The lymphocytes of inimunodeficient control groups were treated with PHA as mitogen. The lymphocyte proliferation was evaluated by MTT and LTT. The results showed a strong correlation between LTT and MITT between immunodeficient patients and healthy controls. The sensitivity test for MTT was 90%, and the sensitivity test for LTT was 98%. MTT method can be considered as a non-radiactive evaluation of cell proliferation. Detecting cell proliferation with accurate, sensitive, fast, easy and safe method is more preferable than LTT.     

Release of mycobacterial antigens

Mycobacterium tuberculosis has evolved from a Mycobacterium canettii-like progenitor pool into one of the most successful and widespread human pathogens. The pathogenicity of M. tuberculosis is linked to its ability to secrete/export/release selected mycobacterial proteins, and it is also established that active release of mycobacterial antigens is a prerequisite for strong immune recognition. Recent research has enabled mycobacterial secretion systems and vesicle-based release of mycobacterial antigens to be elucidated, which together with host-related specificities constitute key variables that determine the outcome of infection. Here, we discuss recently discovered, novel aspects on the nature and the regulation of antigen release of the tuberculosis agent with particular emphasis on the biological characterization of mycobacteria-specific ESX/type VII secretion systems and their secreted proteins, belonging to the Esx, PE, and PPE categories. The importance of specific mycobacterial antigen release is probably best exemplified by the striking differences observed between the cellular events during infection with the ESX-1-deficient, attenuated Mycobacterium bovis BCG compared to the virulent M. tuberculosis, which are clearly important for design of more specific diagnostics and more efficient vaccines.     

A MYLK variant regulates asthmatic inflammation via alterations in mRNA secondary structure

Myosin light-chain kinase (MYLK) is a gene known to be significantly associated with severe asthma in African Americans. Here we further examine the molecular function of a single-nucleotide polymorphism (SNP), located in the non-muscle myosin light-chain kinase isoform (nmMLCK), in asthma susceptibility and pathobiology. We identified nmMLCK variant (reference SNP: rs9840993, {"type":"entrez-nucleotide","attrs":{"text":"NM_053025","term_id":"116008191","term_text":"NM_053025"}}NM_053025: 721C>T, c.439C>T) with a distinct mRNA secondary structure from the other variants. The nmMLCK variant (721C) secondary structure exhibits increased stability with an elongated half-life in the human endothelial cell, and greater efficiency in protein translation initiation owing to an increased accessibility to translation start site. Finally, nmMLCK expression of 721C- and 721T-containing MYLK transgenes were compared in nmMLCK^−/− mice and confirmed deleterious effects of nmMLCK expression on asthmatic indices and implicated the augmented influence of MYLK 721C>T (c.439C>T) SNP on asthma severity. The confirmation of the novel mechanism of the regulation of asthmatic inflammation by a MYLK advances knowledge of the genetic basis for asthma disparities, and further suggests the potential of nmMLCK as a therapeutic target. Our study suggests that in addition to altering protein structure and function, non-synonymous SNPs may also lead to phenotypic disparity by altering protein expression.     

Prediction of breast self-examination in a sample of Iranian women: an application of the Health Belief Model

Background  

Iranian women, many of whom live in small cities, have limited access to mammography and clinical breast examinations. Thus, breast self examination (BSE) becomes an important and necessary approach to detecting this disease in its early stages in order to limit its resultant morbidity and mortality. This study examined constructs arising from the Health Belief Model as predictors of breast self examination behavior in a sample of women living in Bandar Abbas, Iran.