The measurement of reactive oxygen species in human neat semen and in suspended spermatozoa: a comparison

Background  

It is generally accepted that oxidative stress is an important factor in male infertility because it may impair the physiological function of spermatozoa at the molecular level. Nevertheless, although several approaches have been reported, the imbalance between production of reactive oxygen species (ROS) and activity of the antioxidant defense system in semen is difficult to investigate and remains poorly understood.     

Human carcinoma-associated and salivary mucins detected by anti-bovine submaxillary mucin antibodies

Polyclonal rabbit anti-bovine submaxillary mucin antibodies, anti-BSM IgG, were analyzed by autoradiography and densitometry (after SDS electrophoresis and blotting), ELISA, and IRMA assays for reactivity against native antigen BSM, deglycosylated and desialylated BSM, and human salivary and carcinoma-associated mucins. Known human tumor marker CA19-9 antigen reacted with rabbit anti-BSM IgG under different conditions, either soluble or immobilized. As soluble antigen, in IRMA it reacted with anti-BSM antibodies used both as a catcher and a tracer, as well as in combination with monoclonal anti-CA19-9 antibodies as a catcher. MUC1 mucin is a carrier of this carbohydrate antigen, CA19-9, or sialyl-Lewis^a, as well as of CA15-3 antigen, a known breast tumor marker. Autoradiography and densitometry demonstrated binding of anti-BSM IgG to intact MUC1 in a sample of commercial standard preparation of CA19-9 antigen. The same method and analysis demonstrated binding of anti-BSM IgG to MUC1 and to smaller antigens of 85–120 kD in samples containing CA15-3 antigen: commercial standard preparation, human breast tissue, and human milk. In a sample of whole human saliva, reactions of both isoforms of MUC7 were detected by autoradiography, as bands of 85 and 115 kD, and densitogram analysis also demonstrated reaction with MUC5B. Chemical modifications performed as periodate oxidation and desialylation of the BSM demonstrated carbohydrate (i.e., sialic acid) epitope sensitivity for anti-BSM IgG. The results presented in this work indicate that polyclonal anti-BSM antibodies are specific for sialylated carbohydrate structure on mucins and could serve as a tool for investigation of human carcinoma-associated and salivary mucins.     

Changes in nonlinear characteristics of heart rate variability under functional load on the cardiovascular system in healthy subjects and coronary heart disease patients

Some nonlinear characteristics of heart rate variability in the course of functional tests with physical exercise are described. Two groups of volunteers participated in the tests: a control group of 32 healthy subjects (group 1) and a group of 35 coronary heart disease (CHD) patients (group 2). Two series of experiments were performed for each group. An active orthostatic test (AOT) was used in the first series, and a gradually growing physical load on a bicycle ergometer (bicycle ergometer test, BET), in the second series. Along with statistical indices of heart rate (the mean RR interval and standard deviation), nonlinear indices of heart rate were estimated: the correlation dimensionality (D ₂) and approximate entropy (ApEn). Trends of the changes in nonlinear indices of heart rate have been found. The D ₂ and ApEn decreased in both groups of subjects during the AOT and BET under the maximum load. However, the groups of healthy subjects and CHD patients differed in the reactivity of indices, the amplitude of changes in nonlinear indices being narrower in the latter group than in group 1. Differently directed shifts in standard deviation (SDNN) and nonlinear indices have been found. Thus, the data obtained with the use of nonlinear heart rate characteristics show that heart rate under physical load is more multivariate and diverse in healthy subjects at rest and the amplitude of changes during the AOT and BET is greater than in CHD patients, which is a result of the specific autonomic control of heart activity in cardiovascular pathologies.     

Akt Activation Emulates Chk1 Inhibition and Bcl2 Overexpression and Abrogates G2 Cell Cycle Checkpoint by Inhibiting BRCA1 Foci

Akt is perhaps the most frequently activated oncoprotein in human cancers. Overriding cell cycle checkpoint in combination with the inhibition of apoptosis are two principal requirements for predisposition to cancer. Here we show that the activation of Akt is sufficient to promote these two principal processes, by inhibiting Chk1 activation with concomitant inhibition of apoptosis. These activities of Akt cannot be recapitulated by the knockdown of Chk1 alone or by overexpression of Bcl2. Rather the combination of Chk1 knockdown and Bcl2 overexpression is required to recapitulate Akt activities. Akt was shown to directly phosphorylate Chk1. However, we found that Chk1 mutants in the Akt phosphorylation sites behave like wild-type Chk1 in mediating G2 arrest, suggesting that the phosphorylation of Chk1 by Akt is either dispensable for Chk1 activity or insufficient by itself to exert an effect on Chk1 activity. Here we report a new mechanism by which Akt affects G2 cell cycle arrest. We show that Akt inhibits BRCA1 function that induces G2 cell cycle arrest. Akt prevents the translocation of BRCA1 to DNA damage foci and, thereby, inhibiting the activation of Chk1 following DNA damage.