Comparative Estimation of Genetic Diversity in Population Studies using Molecular Sampling and Traditional Sampling Methods

Entomopathogenic nematodes (EPN) are efficient biological pest control agents. Population genetics studies on EPN are seldom known. Therefore, it is of interest to evaluate the significance of molecular sampling method (MSM) for accuracy, time needed, and cost effectiveness over traditional sampling method (TSM). The study was conducted at the Mohican Hills golf course at the state of Ohio where the EPN H. bacteriophora has been monitored for 18 years. The nematode population occupies an area of approximately 3700 m² with density range from 0.25-2 per gram soil. Genetic diversity of EPN was studied by molecular sampling method (MSM) and traditional sampling method (TSM) using the mitochondrial gene pcox1. The MSM picked 88% in compared to TSM with only 30% of sequenced cox 1 gene. All studied genetic polymorphism measures (sequence and haplotype) showed high levels of genetic diversity of MSM over TSM. MSM minimizes the chance of mitochondrial genes amplification from non target organisms (insect or other contaminating microorganisms). Moreover, it allows the sampling of more individuals with a reliable and credible representative sample size. Thus, we show that MSM supersedes TSM in labour intensity, time consumption and requirement of no special experience and efficiency.     

Alterations in the baseline sister-chromatid exchange frequency in human lymphocyte culture following a number of cell divisions

A significant decrease in the baseline of sister-chromatid exchanges (SCEs) was observed in cultured human lymphocytes, if 5-bromodeoxyuridine (BrdU) was added after 60 h of culture, and the cells were harvested at least 24–30 h after BrdU exposure. This decrease is supposed to occur if at least one cell division takes place before the addition of BrdU. For cytogenetic monitoring of mutagenic environmental factors, using human lymphocyte cultures, it is assumed that two time periods are sufficient for comparison.     

Effect of Ambiol on the Ultrastructure of Mitochondria in the Apical Cells of Tubers of Original and Transgenic Potato Plants

The ultrastructure of the mitochondrial apparatus of apical tuber cells of original and transgenic (defensin gene-transfected) potatoes have been compared in normal and ambiol-treated plants, using morphometric approaches. No qualitative or quantitative differences were found between the mitochondria of original and transgenic plants under normal conditions (control). Treatment with ambiol produced only quantitative differences (in the number of mitochondria and their volume) between the cells of original and transgenic plants. This observation has been attributed to (1) changes in the physiology and biochemistry of transgenic plants, induced by the expression of the gene of defensin (hormonal balance, functional activity of the plasmalemmata, etc.), and (2) direct effects of ambiol.     

Relationship of tumor necrosis factor α expression with activation of sphingomyelinase and lipid peroxidation after removal of cholestatic factor

The goal of this work was to study the expression of tumor necrosis factor α (TNFα), sphingomyelin cycle activation, and lipid peroxidation (LPO) processes after the removal of a cholestatic factor in the liver subjected to different durations of cholestasis. Restored bile flow after a 9-day hepatic cholestasis normalized sphingomyelinase (SMase) activity and levels of TNFα and LPO products. The removal of a cholestatic factor after a 12-day cholestasis did not normalize the studied parameters: SMase activity and the levels of TNFα and LPO products remained much higher compared to control. A significant positive correlation between TNFα expression, SMase activity, and LPO rate has been revealed. The obtained data indicate that hepatocyte apoptosis after bile outflow restoration in late cholestasis can be due to the activation of the sphingomyelin cycle, LPO, and TNFα expression. The synergistic interaction can sharply increase the proapoptotic capacity of each of these factors since TNFα activates SMase and LPO, SMase activity depends on the LPO rate, while ceramide, an SMase-produced secondary messenger of apoptosis, can induce oxidative stress.     

Sildenafil attenuates pulmonary inflammation and fibrin deposition, mortality and right ventricular hypertrophy in neonatal hyperoxic lung injury

Background

Phosphodiesterase-5 inhibition with sildenafil has been used to treat severe pulmonary hypertension and bronchopulmonary dysplasia (BPD), a chronic lung disease in very preterm infants who were mechanically ventilated for respiratory distress syndrome.

Methods

Sildenafil treatment was investigated in 2 models of experimental BPD: a lethal neonatal model, in which rat pups were continuously exposed to hyperoxia and treated daily with sildenafil (50–150 mg/kg body weight/day; injected subcutaneously) and a neonatal lung injury-recovery model in which rat pups were exposed to hyperoxia for 9 days, followed by 9 days of recovery in room air and started sildenafil treatment on day 6 of hyperoxia exposure. Parameters investigated include survival, histopathology, fibrin deposition, alveolar vascular leakage, right ventricular hypertrophy, and differential mRNA expression in lung and heart tissue.

Results

Prophylactic treatment with an optimal dose of sildenafil (2 × 50 mg/kg/day) significantly increased lung cGMP levels, prolonged median survival, reduced fibrin deposition, total protein content in bronchoalveolar lavage fluid, inflammation and septum thickness. Treatment with sildenafil partially corrected the differential mRNA expression of amphiregulin, plasminogen activator inhibitor-1, fibroblast growth factor receptor-4 and vascular endothelial growth factor receptor-2 in the lung and of brain and c-type natriuretic peptides and the natriuretic peptide receptors NPR-A, -B, and -C in the right ventricle. In the lethal and injury-recovery model we demonstrated improved alveolarization and angiogenesis by attenuating mean linear intercept and arteriolar wall thickness and increasing pulmonary blood vessel density, and right ventricular hypertrophy (RVH).

Conclusion

Sildenafil treatment, started simultaneously with exposure to hyperoxia after birth, prolongs survival, increases pulmonary cGMP levels, reduces the pulmonary inflammatory response, fibrin deposition and RVH, and stimulates alveolarization. Initiation of sildenafil treatment after hyperoxic lung injury and continued during room air recovery improves alveolarization and restores pulmonary angiogenesis and RVH in experimental BPD.     

Activation of key proenzymes of the blood coagulation system by the fibrin E fragment

Plasminogen and prothrombin are key proenzymes of fibrinolytic and clotting system. It is known that they can be activated by indirect activators streptokinase and staphylocoagulase. In this paper it is shown that fibrin E fragment purified from DD-E complex induced catalytic activity in plasminogen and clotting activity in prothrombin. Streptokinase increased 2 times the rate of catalytic activity induction by E fragment in prothrombin. It's possibly that process is one of the factors providing for rethrombosis after thrombolytic therapy of myocardial infarction.     

Periodic variations of spontaneous chromosome aberration rate in human blood lymphocytes

Spontaneous chromosome aberration rate in human blood lymphocytes was studied using the data collected during 30 years. Seasonal variation was found. An absolute maximum of chromosome aberration rate was observed in winter and a local maximum, in summer. In spring and autumn, this value decreased. There was a statistically significant trend towards higher frequencies of aberrant metaphases during the period studied. A periodic pattern of changes in the chromosome aberration frequency was found. The data fitted a sinusoid with a period of 4.5 years.     

The role of fibrin clot degradation products in the regulation of vital functions of PC-12 cells

The products of the fibrin clot hydrolysis performed by PC-12 cells modulated dose-dependently the rate of cell proliferation and favored their survival when seeded in suboptimal density. Co-incubation of PC-12 cells with fibrin degradation products enhanced cell adhesion to tissue culture plastic, as well as the number of nicotinic acetylcholine receptor alpha3 and alpha5 subunits expressed. It was demonstrated that, in fact, such a heterogeneous and comprehensive influence was a sum of effects exerted by different fibrin fragments. Low molecular weight fraction (below 30 kDa), but not a purified alphaC-domain, stimulated PC-12 cell proliferation, diminished their adhesion to plastic, increased nicotinic receptor expression and caused processes outgrowth. On the contrary, high molecular weight products, in particular D, DD and E fragments, enhanced PC-12 adhesion to plastic and, as a result, slowed cell division. Both high and low molecular weight fragments favored the survival of PC-12 cells. These results showed that fibrin degradation products support the vital functions of neuron-like cells, favor their contacts with extracellular surrounding and act as neurotrophic factors.