Hormonal adaptation determines the increase in muscle mass and strength during low-intensity strength training without relaxation

The study was designed to test the hypothesis that, during strength training, a restricted blood supply to the working muscles stimulates the secretion of anabolic hormones and an increase in the muscle mass and strength can be achieved with significantly lower training loads. During eight weeks, three times a week, 18 young, physically active males trained their leg extensor muscles. Nine subjects (group I) worked at 80% of the maximal voluntary contraction (MVC), whereas the rest (group II) performed their exercise without relaxation and at a lower load (50% MVC). The total training load in group II was significantly lower than in group I (77 ± 5 vs. 157 ± 7 kJ, respectively). The eight-week training of both groups significantly increased the mean maximum strength (by 35 and 21% in groups I and II, respectively) and volume (by 17 and 9%, respectively) of the muscles trained (however, the differences between the groups with respect to these changes were nonsignificant). Group I displayed a higher increase in the blood level of creatine phosphokinase than group II, while group II showed a greater increase in the blood concentration of lactate. In contrast to group I, group II displayed a significant increase in the blood concentrations of growth hormone, insulin-like growth factor 1 (IGF-1), and cortisol. Hence, the suggestion that the secretion of metabolic hormones is triggered by a metabolic, rather than mechanical, stimulus from working muscles seems plausible.     

Development of a Humanized Antibody 5D3Hu against the PRAME Tumor Antigen

Russian Journal of Bioorganic Chemistry - The PRAME antigen, which is a significant target for monoclonal antibodies, is a tumor-specific marker that is active at all stages of tumor cell...     

Characterization of bacterial artificial chromosome transgenic mice expressing mCherry fluorescent protein substituted for the murine smooth muscle α‐actin gene

Smooth muscle α actin (SMA) is a cytoskeletal protein expressed by mesenchymal and smooth muscle cell types, including mural cells (vascular smooth muscle cells and pericytes). Using Bacterial Artificial Chromosome (BAC) recombineering technology, we generated transgenic reporter mice that express a membrane localized cherry red fluorescent protein (mCherry), driven by the full‐length SMA promoter and intronic sequences. We determined that the founders and F1 progeny of five independent lines contain 1–3 copies of the mCherry‐substituted BAC vector. Furthermore, we characterized the expression of SMA‐mCherry in relation to endogenous SMA in the embryo and in adult tissues, and found that the transgenic reporter in each line recapitulated endogenous SMA expression at all time points. We were also able to isolate SMA expressing cells from embryonic tissues using fluorescence‐activated cell sorting (FACS). We demonstrated that this marker can be combined with other vital fluorescent reporters and it can be used for live imaging of embryonic cardiodynamics. Therefore, these transgenic mice will be useful for isolating live SMA‐expressing cells via FACS and for studying the emergence, behavior, and regulation of SMA‐expressing cells, including vascular smooth muscle cells and pericytes throughout embryonic and postnatal development. genesis 48:457–463, 2010. © 2010 Wiley‐Liss, Inc.     

Exogenous proteins in exhaled human breath condensate

In the course of analysis of protein composition of exhaled breath to diagnose diseases of the respiratory system the problem is raised to distinguish between proteins, expressed in lung tissues and in respiratory tract (endogenous) and those that got into the respiratory system from the ambient air in the process of respiration (exogenous). In this work, an attempt is made to estimate the constitution of exogenous proteins in exhaled air with mass spectrometry and nanoflow high performance liquid chromatography (nano-HPLC). Six months’ indoors isolation of healthy donors with air being cleaned of dust leads to the removal from the spectrum of exhaled proteins of some keratins that are therefore considered to be exogenous. Nonkeratin proteins may also circulate between ambient air and human airways, but their concentration appears to be significantly lower than keratin concentrations (especially than the epidermis keratin). Among nonkeratins, dermicidin seems to be the most significant exogenous protein of the exhaled air. Conclusions concerning the diagnostic value of exhaled proteins can be made only after careful comparison of results of quantitative and qualitative analyses of their normal and pathological composition for a statistically significant sample of donors.     

Variability of the healthy human proteome

The aim of this review is to analyze results of studies on characteristics of protein variability and diversity of posttranslational modifications of proteins in healthy humans. Numerous studies have demonstrated that a proteomic profile is characterized by significant intra- and inter-individual variability, and quite often natural (“normal”) variability of some proteins can be comparable to changes observed in pathological processes. Results obtained by our research group have demonstrated high intra-individual variability of serum low-molecular subproteome of healthy volunteers, certified by a special medial committee (the coefficient of variation (CV) of 42.6%). The proteins characterized by high variability under normal conditions (e.g. haptoglobin — 0–40 mg/ml; lysozyme — 0.01–0.1 mg/ml; C-reactive protein — 0.01–0.3 mg/ml) cannot be considered as potential biomarkers of diseases. On the contrary, proteins and peptides characterized by insignificant dispersion in healthy population (such as albumin ( CV = 9%); transferrin-(CV = 14%); C3c complement (CV = 17%), α-1 acid glycoprotein (CV = 21%), α-2-macroglobulin (CV = 20%); transthyretin fragment (CV = 28.3%) and α2-HS-glycoprotein βchain (CV = 29.7%)) can provide valuable information about the state of health. Thus, studies of plasticity in the proteomic profiles of healthy humans will help to correct reference intervals used in clinical proteomics.