Frequency of detection of Ureaplasma urealyticum and Mycoplasma hominis in cervical canal and the Douglas pouch of infertile and fertile women

The group of organisms commonly referred to as genital mycoplasmas comprise species most often found in genitourinary tract of sexually active adults as common commensal inhabitants, or pathogens which can possibly cause many different pathologies like: non-gonococcal urethritis, bacterial vaginosis, cervicitis, endometritis or pelvic inflammatory disease. The problem of their morbidity and the possible influence they have on human fertility is still not clear. The aim of this study was to find out whether two investigated species- Ureaplasma urealyticum and Mycoplasma hominis can be detect more often in a group of infertile women. 74 women participated in the study and were assigned to one of 2 groups of patients: infertile women and fertile women without any sign of genital tract infection. Swabs from the cervical canal of the uterus and the fluid from the Douglas pouch were taken during the gynecological examination and laparoscopic procedure. Two diagnostic methods were used: biochemical method- commercial diagnostic kit- Mycoplasma IST 2 and PCR method. The results showed that Ureaplasma urealyticum and Mycoplasma hominis were detected among both fertile and infertile women with nearly the same frequency, much more often in cervical canal than in the Douglas pouch. Ureaplasma urealyticum was more common pathogen than Mycoplasma hominis in both groups and locations. The achieved results point out that the role of genital mycoplasmas in human infertility is still unclear and require further investigations.     

Liming to remediate Ni contaminated soils with diverse properties and a wide range of Ni concentration

Historic emissions from a Ni refinery at Port Colborne, Ontario, caused Ni contamination of regional soils and raised concerns about potential Ni phytotoxicity. Previous tests revealed that if these soils were made alkaline and fertilized with Mn and other common nutrients as needed to maintain fertility of such alkaline soils, full remediation (prevention of Ni phytotoxicity) would be obtained. This experiment was conducted to test this method of remediation on diverse soils from Port Colborne, and to evaluate chemical extraction tests which would be predictive of plant uptake and potential for Ni phytotoxicity in Ni-contaminated soils. Ten soils with varied levels of Ni contamination and varied soil properties were amended with limestone or nitric acid to raise or lower pH so that a wide pH range could be examined for the soils. For lower Ni organic and mineral soils near the Ontario remediation limit (200 mg/kg), neither crop suffered Ni phytotoxicity at any pH tested. Only when more highly contaminated soils were strongly acidic did Ni phytotoxicity occur. Phytotoxic soils were fully remediated by making soils alkaline even for these Ni-sensitive crop species. Only the most contaminated organic soil remained slightly toxic – but this soil was remarkably contaminated (over 1.1% of Ni). The Sr nitrate extraction method was much more effective in predicting plant Ni concentrations than the DTPA method. This test provides an inexpensive soil extraction result highly predictive of potential for Ni phytotoxicity across soils.     

Cases of coat colour anomalies in the common shrew, Sorex araneus L

Coat colour anomalies in the common shrew, Sorex araneus L., in the geographical range of this species, including Poland, are extremely rare. This study describes atypically coloured common shrews. Light colouration of the coat is a result of lack ofpigment in the entire hair or hair fragments. It appears that atypically coloured shrews occur more often in isolated populations whose gene transfer with neighboring populations is limited.     

Membrane-permeable calmodulin inhibitors (e.g. W-7/W-13) bind to membranes, changing the electrostatic surface potential: dual effect of W-13 on epidermal growth factor receptor activation

Membrane-permeable calmodulin inhibitors, such as the napthalenesulfonamide derivatives W-7/W-13, trifluoperazine, and calmidazolium, are used widely to investigate the role of calcium/calmodulin (Ca2+/CaM) in living cells. If two chemically different inhibitors (e.g. W-7 and trifluoperazine) produce similar effects, investigators often assume the effects are due to CaM inhibition. Zeta potential measurements, however, show that these amphipathic weak bases bind to phospholipid vesicles at the same concentrations as they inhibit Ca2+/CaM; this suggests that they also bind to the inner leaflet of the plasma membrane, reducing its negative electrostatic surface potential. This change will cause electrostatically bound clusters of basic residues on peripheral (e.g. Src and K-Ras4B) and integral (e.g. epidermal growth factor receptor (EGFR)) proteins to translocate from the membrane to the cytoplasm. We measured inhibitor-mediated translocation of a simple basic peptide corresponding to the calmodulin-binding juxtamembrane region of the EGFR on model membranes; W-7/W-13 causes translocation of this peptide from membrane to solution, suggesting that caution must be exercised when interpreting the results obtained with these inhibitors in living cells. We present evidence that they exert dual effects on autophosphorylation of EGFR; W-13 inhibits epidermal growth factor-dependent EGFR autophosphorylation under different experimental conditions, but in the absence of epidermal growth factor, W-13 stimulates autophosphorylation of the receptor in four different cell types. Our interpretation is that the former effect is due to W-13 inhibition of Ca2+/CaM, but the latter results could be due to binding of W-13 to the plasma membrane.     

Production of Antifungal Chitinase by Aspergillus niger LOCK 62 and Its Potential Role in the Biological Control

Aspergillus niger LOCK 62 produces an antifungal chitinase. Different sources of chitin in the medium were used to test the production of the chitinase. Chitinase production was most effective when colloidal chitin and shrimp shell were used as substrates. The optimum incubation period for chitinase production by Aspergillus niger LOCK 62 was 6?days. The chitinase was purified from the culture medium by fractionation with ammonium sulfate and affinity chromatography. The molecular mass of the purified enzyme was 43?kDa. The highest activity was obtained at 40?°C for both crude and purified enzymes. The crude chitinase activity was stable during 180?min incubation at 40?°C, but purified chitinase lost about 25?% of its activity under these conditions. Optimal pH for chitinase activity was pH 6–6.5. The activity of crude and purified enzyme was stabilized by Mg²⁺ and Ca²⁺ ions, but inhibited by Hg²⁺ and Pb²⁺ ions. Chitinase isolated from Aspergillus niger LOCK 62 inhibited the growth of the fungal phytopathogens: Fusarium culmorum, Fusarium solani and Rhizoctonia solani. The growth of Botrytis cinerea, Alternaria alternata, and Fusarium oxysporum was not affected.     

The beneficial effect of small toxic molecules on dormancy alleviation and germination of apple embryos is due to NO formation

Deep dormancy of apple (Malus domestica Borkh.) seeds is terminated by a 3-month-long cold stratification. It is expressed by rapid germination of seeds and undisturbed growth of seedlings. However, stimulation of germination of isolated apple embryos is also observed after applying inhibitors of cytochrome c oxidase: nitric oxide (NO) or hydrogen cyanide (HCN) during the first 3–6 h of imbibition of dormant embryos. The aim of this work was to compare the effect of yet another toxic gaseous molecule carbon monoxide (CO) with the effects of HCN and NO on germination of apple embryos and growth and development of young seedlings. We demonstrated that stimulation of germination after short-term pre-treatment with HCN, NO or CO was accompanied by enhanced NO emission from the embryo axes during their elongation. Moreover, similarly high NO production from non-dormant embryos, after cold stratification, was detected. Therefore, we propose that NO may act as signaling molecule in apple embryo dormancy break.     

Gas in Scattering Media Absorption Spectroscopy (GASMAS) Detected Persistent Vacuum in Apple Tissue After Vacuum Impregnation

The microstructure and the capillary pressure of the pore space are important variables for better understanding of the complex phenomena occurring during vacuum impregnation (VI) of plant tissues. In this study, we used GASMAS (Gas in Scattering Media Absorption Spectroscopy) of oxygen to, non-destructively, measure the dynamics of the internal pressure in apple pieces after restoration of the atmospheric pressure. Apple pieces were impregnated with isotonic sucrose solution (18% w/v) at different reduced pressures (15, 30, 45 kPa (abs.)). After restoration of the atmospheric pressure, the pressure of the remaining pore space gas could remain as low as 50 kPa (abs) and rise slowly toward ambient over a time scale of hours. Both the residual vacuum and the timescale of pressure equilibration with ambient varied with applied vacuum level and apple variety. It is proposed that at least a part of the pore space of apples may be hydrophobic, giving rise to a negative Laplace pressure, and thus the convective flow of impregnating solution is arrested at a mechanical equilibrium where internal pressure is lower than external pressure. Further pressure equilibration can then only be achieved either by gas diffusion in gas phase, or by gradual wetting of the pores.     

Galphaq binds two effectors separately in cells: evidence for predetermined signaling pathways

G-proteins transduce signals along diverse pathways, but the factors involved in pathway selection are largely unknown. Here, we have studied the ability of Gα_q to select between two effectors—mammalian inositide-specific phospholipase Cβ (PLCβ) and phosphoinositide-3-kinase (PI3K)—in human embryonic kidney 293 cells. These studies were carried out by measuring interactions between eCFP- and eYFP-tagged proteins using Forster resonance energy transfer in the basal state and during stimulation. Instead of association of Gα_q with effectors through diffusion and exchange, we found separate and stable pools of Gα_q-PLCβ and Gα_q-PI3K complexes existing throughout the stimulation cycle. These separate complexes existed despite the ability of Gα_q to simultaneously bind both effectors as determined by in vitro measurements using purified proteins. Preformed G-protein/effector complexes will limit the number of pathways that a given signal will take, which may simplify predictive models.     

Degenerate specificity of PDZ domains from RhoA-specific nucleotide exchange factors PDZRhoGEF and LARG

PDZ domains are ubiquitous protein-protein interaction modules which bind short, usually carboxyterminal fragments of receptors, other integral or membrane-associated proteins, and occasionally cytosolic proteins. Their role in organizing multiprotein complexes at the cellular membrane is crucial for many signaling pathways, but the rules defining their binding specificity are still poorly understood and do not readily explain the observed diversity of their known binding partners. Two homologous RhoA-specific, multidomain nucleotide exchange factors PDZRhoGEF and LARG contain PDZ domains which show a particularly broad recognition profile, as suggested by the identification of five diverse biological targets. To investigate the molecular roots of this phenomenon, we constructed a phage display library of random carboxyterminal hexapeptides. Peptide variants corresponding to the sequences identified in library selection were synthesized and their affinities for both PDZ domains were measured and compared with those of peptides derived from sequences of natural partners. Based on the analysis of the binding sequences identified for PDZRhoGEF, we propose a sequence for an 'optimal' binding partner. Our results support the hypothesis that PDZ-peptide interactions may be best understood when one considers the sum of entropic and dynamic effects for each peptide as a whole entity, rather than preferences for specific residues at a given position.