Molecular Diagnostics of the Involvement of Visually Normal Mucosa in the Malignancy Process in Urothelial Bladder Cancer

Molecular Biology - Immunofluorescent method by flow cytometry was used to quantify the expression of the tumor-associated protein βIII-tubulin (TUBB3) in the tissue of urothelial bladder...     

Non-weak inhibition and phase resetting at negative values of phase in cells with fast-slow dynamics at hyperpolarized potentials

Phase response is a powerful concept in the analysis of both weakly and non-weakly perturbed oscillators such as regularly spiking neurons, and is applicable if the oscillator returns to its limit cycle trajectory between successive perturbations. When the latter condition is violated, a formal application of the phase return map may yield phase values outside of its definition domain; in particular, strong synaptic inhibition may result in negative values of phase. The effect of a second perturbation arriving close to the first one is undetermined in this case. However, here we show that for a Morris–Lecar model of a spiking cell with strong time scale separation, extending the phase response function definition domain to an additional negative value branch allows to retain the accuracy of the phase response approach in the face of such strong inhibitory coupling. We use the resulting extended phase response function to accurately describe the response of a Morris–Lecar oscillator to consecutive non-weak synaptic inputs. This method is particularly useful when analyzing the dynamics of three or more non-weakly coupled cells, whereby more than one synaptic perturbation arrives per oscillation cycle into each cell. The method of perturbation prediction based on the negative-phase extension of the phase response function may be applicable to other excitable cell models characterized by slow voltage dynamics at hyperpolarized potentials.     

EPR study of the oxidation reaction of nickel(0) phosphine complexes with Lewis and Brønsted acids

The oxidation of Ni(PPh₃)₄ with BF₃ · OEt₂, H₃CCOOH, and F₃CCOOH, and that of (PPh₃)₂Ni(C₂H₄) with BF₃ · OEt₂ is studied by EPR spectroscopy. The reaction of the Ni(0) complexes with BF₃ · OEt₂ gives Ni(II) complexes with which they react to form Ni(I) compounds with covalent Ni-F and Ni-B bonds that transform with excess BF₃ · OEt₂ into cationic paramagnetic Ni(I) complexes. Acetic acid also adds oxidatively to Ni(PPh₃)₄ to form a Ni(II) complex that reacts further to give Ni(I) hydride and carboxylate complexes. The Ni(I) hydride is transformed by the acid into the Ni(I) carboxylate with release of hydrogen, the amount of which depends on the rate of acid addition. The following Ni(I) complexes are identified in the reaction medium: [Ni(PPh₃)₃]BF₄, [(PPh₃)₂Ni(OEt₂)]BF₄, [(PPh₃)Ni(OEt₂)_n]BF₄, (PPh₃)₂NiBF₂, (PPh₃)₃NiOOCCH₃, and [(PPh₃)₂Ni(OEt₂)P(OEt)₃]BF₄. Oxidation schemes of Ni(0) complexes by Lewis and Brønsted acids are given.     

Localization of point mutations in the coding part of the VHL gene in clear cell renal cancer

VHL gene is often inactivated in sporadic clear cell renal cancer (CCRC) due to somatic mutations, and it's germline mutations cause hereditary CCRC--von Hippel-Lindau syndrome. Localization of mutations in VHL, identification of new mutations and their influence on CCRC progression and sensitivity to targeted therapy are actual problems in modern oncogenetics. We have provided search and characterization of mutations in 248 primary CCRC using SSCP-analysis and sequencing. Somatic mutations were detected in 37.5% of samples, 72% of mutations were identified for the first time. New missense-mutations were analyzed by alignment programs and three-dimensional structure modeling. Mutation frequency was compared in different groups of patients in respect to stage, grade, and metastases. It was demonstrated that 39.1% samples with stage I harbor somatic mutations, however, no association with progression or metastases was found. We also have investigated localization of mutations in the VHL coding part and positions of missense-mutations and inframe deletions/insertions focusing on VHL critical sequences. VHL mutation analysis performed in this study improve the possibilities of laboratory diagnostics of familial and sporadic CCRC.     

First detection, isolation and molecular characterization of infectious salmon anaemia virus associated with clinical disease in farmed Atlantic salmon (Salmo salar) in Chile

Background  

Several forms of progressive retinal atrophy (PRA) segregate in more than 100 breeds of dog with each PRA segregating in one or a few breeds. This breed specificity may be accounted for by founder effects and genetic drift, which have reduced the genetic heterogeneity of each breed, thereby facilitating the identification of causal mutations. We report here a new form of PRA segregating in the Border Collie breed. The clinical signs, including the loss of night vision and a progressive loss of day vision, resulting in complete blindness, occur at the age of three to four years and may be detected earlier through systematic ocular fundus examination and electroretinography (ERG).     

Functional activity of photoreceptor cyclic nucleotide-gated channels is dependent on the integrity of cholesterol- and sphingolipid-enriched membrane domains

Rod and cone photoreceptor cyclic nucleotide-gated (CNG) channels play pivotal roles in phototransduction. This work investigates the functional significance of photoreceptor CNG channel association with membrane microdomains enriched in raft lipids, cholesterol and sphingolipids. The primary subunits of cone and rod CNG channels, CNGA3 and CNGA1, respectively, were heterologously expressed in HEK 293 cells, and channel activity was determined by ratiometric measurement of [Ca (2+)] i in response to cyclic guanosine monophosphate (cGMP) stimulation. CNGA3 was found to be largely insoluble following Triton X-100 extraction and cofractionationed with biochemically isolated membrane domains enriched in caveolin-1. Cofractionation of both natively expressed CNGA3 and CNGB1 (the modulatory subunit of the rod CNG channel) with the low buoyant density, caveolin-1-enriched membranes was also confirmed in mouse retinas. The functional significance of this association was established by the observed negative effects of depletion of raft lipids on the channel activity. Treatment with the cholesterol depleting agent, methyl-beta-cyclodextrin (MCD), significantly inhibited CNGA3 and CNGA1 activation in response to cGMP stimulation. MCD treatment lowered cellular cholesterol levels by approximately 45% without altering fatty acid composition, suggesting that the inhibition of channel activity by MCD treatment is not due to perturbation of other membrane lipids. Treatment with the sphingolipid biosynthesis inhibitor myriocin resulted in impaired activation and cytosolic redistribution of CNGA3, suggesting that the integrity of the membrane domains is critical for the channel cellular processing and plasma membrane localization. This study demonstrates the association of photoreceptor CNG channels with membrane domains enriched in raft lipids and indicates, for the first time, that raft lipids modulate the plasma membrane localization and functional activity of photoreceptor CNG channels.     

Structuring of the cyanobacterial community by pelagic fish in subtropical reservoirs: experimental evidence from Australia

1. Subtropical reservoirs of Australia are commonly subject to summer blooms of cyanobacteria. The potential for food web manipulation to control cyanobacterial blooms was investigated in Lake Maroon, south east Queensland using enclosures in which the density of the Australian gudgeon Hypseleotris spp. was manipulated. 2. Zooplankton biomass and community structure were strongly affected by fish density. A size dependent predation effect of Hypseleotris on zooplankton was observed at ambient fish densities, and the community shifted towards a dominance of copepod juveniles and nauplii. Substantial increases in the populations of Ceriodaphnia and calanoid copepods were observed at low fish densities and in the absence of fish. 3. At ambient fish densities total phytoplankton and the proportion of cyanobacteria were maintained at levels similar to those prevailing at day 0. Total phytoplankton and the proportion of cyanobacteria decreased substantially at low fish densities and in the absence of fish. Chlorophytes became dominant in the ‘no fish’ treatment and the grazing‐resistant species Oocystis and Dictyosphaerium were significantly higher than at ambient fish densities. 4. The experiment demonstrated a strong positive relationship between Hypseleotris density and cyanobacteria, and the results suggest that subtropical reservoirs may be suited to food web manipulation as a means of controlling summer cyanobacterial blooms.     

Main Factors of a Decrease in Stress Resistance in Six- to Eight-Year-Old Children with Long-Term Consequences of Perinatal CNS Pathology during Transition to School Period of Their Activity

Central disorders that determine a decrease in stress resistance and compensatory-adaptive possibilities of six- to eight-year-old children with remote consequences of a perinatal hypoxic-ischemic CNS injury were comprehensively characterized on the basis of literature data and results of the complex psychophysiological and neurophysiological examination using complementary integral indices. The main factors responsible for constraints of adaptive possibilities of such children at a preschool age and aggravation of the central regulatory disorders during the transition to school period of their life were revealed.     

三氧化二砷对食管癌细胞增殖和热休克蛋白70表达的影响

目的：研究三氧化二砷（As2O3）对食管癌细胞增殖和热休克蛋白70（HSP70）表达的影响。方法：通过相差显微镜、流式细胞术、免疫细胞化学染色和免疫印迹分析等方法观察As2O3对人食管癌细胞株EC1的作用效果和作用机制。结果：与对照组相比,经2μmol/L和5μmol/Las2O3作用的细胞出现明显的生长抑制,G2/M期细胞比例增加;2μmol/Las2O3作用48h后经Ecl细胞HSP70（heat shock protein70）及HSC70(heat shock cognate protein70)表达均增加。结论：As2O3诱导食管癌细胞G2/M期阻滞抑制细胞增殖和生长;HSP70的升高是细胞对As2O3作用后出现的应激反应,并与细胞周期阻滞相关。