The effect of diclofenac sodium on neural tube development in the early stage of chick embryos

Background: Neural tube defects are congenital malformations of the central nervous system. Genetic predisposition and some environmental factors play an important role in the development of neural tube defects. This study aimed to investigate the effects of diclofenac sodium on the neural tube development in a chick embryo model that corresponds to the first month of vertebral deve- lopment in mammals.  Materials and methods: Seventy-five fertile, specific pathogen-free eggs were incubated for 28 h and were divided into five groups of 15 eggs each. Diclofenac sodium was administered via the sub-blastodermic route at this stage. Incubation was continued till the end of the 48th h. All eggs were then opened and embryos were dissected from embryonic membranes and evaluated morphologically and histopathologically.  Results: It was determined that the use of increasing doses of diclofenac sodium led to defects of midline closure in early chicken embryos. There were statistically significant differences in neural tube positions (open or close) among the groups. In addition; crown–rump length, somite number were significantly decreased in high dose experimental groups compared with control group.  Conclusions: This study showed that development of neurons is affected in chi- cken embryos after administration of diclofenac sodium. The exact teratogenic mechanism of diclofenac sodium is not clear; therefore it should be investigated.

Identification of PLCγ-Dependent and -Independent Events during Fertilization of Sea Urchin Eggs

AbstractAt fertilization, sea urchin eggs undergo a series of activation events, including a Ca2+action potential, Ca2+release from the endoplasmic reticulum, an increase in intracellular pH, sperm pronuclear formation, MAP kinase dephosphorylation, and DNA synthesis. To examine which of these events might be initiated by activation of phospholipase Cγ (PLCγ), which produces the second messengers inositol trisphosphate (IP3) and diacylglycerol, we used recombinant SH2 domains of PLCγ as specific inhibitors. Sea urchin eggs were co-injected with a GST fusion protein composed of the two tandem SH2 domains of bovine PLCγ and (1) Ca2+green dextran to monitor intracellular free Ca2+, (2) BCECF dextran to monitor intracellular pH, (3) Oregon Green dUTP to monitor DNA synthesis, or (4) fluorescein 70-kDa dextran to monitor nuclear envelope formation. Microinjection of the tandem SH2 domains of PLCγ produced a concentration-dependent inhibition of Ca2+release and also inhibited cortical granule exocytosis, cytoplasmic alkalinization, MAP kinase dephosphorylation, DNA synthesis, and cleavage after fertilization. However, the Ca2+action potential, sperm entry, and sperm pronuclear formation were not prevented by injection of the PLCγSH2 domain protein. Microinjection of a control protein, the tandem SH2 domains of the phosphatase SHP2, had no effect on Ca2+release, cortical granule exocytosis, DNA synthesis, or cleavage. Specificity of the inhibitory action of the PLCγSH2 domains was further indicated by the finding that microinjection of PLCγSH2 domains that had been point mutated at a critical arginine did not inhibit Ca release at fertilization. Additionally, Ca2+release in response to microinjection of IP3, cholera toxin, cADP ribose, or cGMP was not inhibited by the PLCγSH2 fusion protein. These results indicate that PLCγ plays a key role in several fertilization events in sea urchin eggs, including Ca2+release and DNA synthesis, but that the action potential, sperm entry, and male pronuclear formation can occur in the absence of PLCγ activation or Ca2+increase

Domain I of β2GPI is capable of blocking serum IgA antiphospholipid antibodies binding in vitro: an effect enhanced by PEGylation

OBJECTIVES: This study aims to inhibit antiphospholipid syndrome (APS) serum derived IgA anti-beta-2-glycoprotein I (aβ2GPI) binding using Domain I (DI). METHODS: Serum from 13 APS patients was tested for IgA aβ2GPI and Anti-Domain I. Whole IgA was purified by peptide M affinity chromatography from positive serum samples. Serum was tested for IgA aβ2GPI binding in the presence and absence of either DI or of two biochemically modified variants containing either 20 kDa of poly(ethylene glycol) (PEG) or 40 kDa of PEG. RESULTS: Significant inhibition with DI was possible with average inhibition of 23% ( N = 13). Further inhibitions using 20 kDa PEG-DI and 40 kDa PEG-DI variants showed significant inhibition ( p = 0.0001) with both the 40 kDa PEG-DI and 20 kDa PEG-DI variants showing increased inhibition compared with DI alone ( p = 0.0001 and p = 0.001, n = 10). CONCLUSIONS: Inhibition of IgA aβ2GPI by DI is possible and can be enhanced by biochemical modification in a subset of patients

Domain I of beta 2GPI is capable of blocking serum IgA antiphospholipid antibodies binding in vitro: an effect enhanced by PEGylation

Objectives This study aims to inhibit antiphospholipid syndrome (APS) serum derived IgA anti-beta-2-glycoprotein I (aβ2GPI) binding using Domain I (DI). Methods Serum from 13 APS patients was tested for IgA aβ2GPI and Anti-Domain I. Whole IgA was purified by peptide M affinity chromatography from positive serum samples. Serum was tested for IgA aβ2GPI binding in the presence and absence of either DI or of two biochemically modified variants containing either 20 kDa of poly(ethylene glycol) (PEG) or 40 kDa of PEG. Results Significant inhibition with DI was possible with average inhibition of 23% (N = 13). Further inhibitions using 20 kDa PEG-DI and 40 kDa PEG-DI variants showed significant inhibition (p = 0.0001) with both the 40 kDa PEG-DI and 20 kDa PEG-DI variants showing increased inhibition compared with DI alone (p = 0.0001 and p = 0.001, n = 10). Conclusions Inhibition of IgA aβ2GPI by DI is possible and can be enhanced by biochemical modification in a subset of patients

Bacteriophage- based tests for the detection of Mycobacterium tuberculosis in clinical specimens: a systematic review and meta- analysis

BACKGROUND: Sputum microscopy, the most important conventional test for tuberculosis, is specific in settings with high burden of tuberculosis and low prevalence of non tuberculous mycobacteria. However, the test lacks sensitivity. Although bacteriophage-based tests for tuberculosis have shown promising results, their overall accuracy has not been systematically evaluated. METHODS: We did a systematic review and meta-analysis of published studies to evaluate the accuracy of phage-based tests for the direct detection of M. tuberculosis in clinical specimens. To identify studies, we searched Medline, EMBASE, Web of science and BIOSIS, and contacted authors, experts and test manufacturers. Thirteen studies, all based on phage amplification method, met our inclusion criteria. Overall accuracy was evaluated using forest plots, summary receiver operating (SROC) curves, and subgroup analyses. RESULTS: The data suggest that phage-based assays have high specificity (range 0.83 to 1.00), but modest and variable sensitivity (range 0.21 to 0.88). The sensitivity ranged between 0.29 and 0.87 among smear-positive, and 0.13 to 0.78 among smear-negative specimens. The specificity ranged between 0.60 and 0.88 among smear-positive and 0.89 to 0.99 among smear-negative specimens. SROC analyses suggest that overall accuracy of phage-based assays is slightly higher than smear microscopy in direct head-to-head comparisons. CONCLUSION: Phage-based assays have high specificity but lower and variable sensitivity. Their performance characteristics are similar to sputum microscopy. Phage assays cannot replace conventional diagnostic tests such as microscopy and culture at this time. Further research is required to identify methods that can enhance the sensitivity of phage-based assays without compromising the high specificity

Huntington's disease cerebrospinal fluid seeds aggregation of mutant huntingtin

Huntington's disease (HD), a progressive neurodegenerative disease, is caused by an expanded CAG triplet repeat producing a mutant huntingtin protein (mHTT) with a polyglutamine-repeat expansion. Onset of symptoms in mutant huntingtin gene-carrying individuals remains unpredictable. We report that synthetic polyglutamine oligomers and cerebrospinal fluid (CSF) from BACHD transgenic rats and from human HD subjects can seed mutant huntingtin aggregation in a cell model and its cell lysate. Our studies demonstrate that seeding requires the mutant huntingtin template and may reflect an underlying prion-like protein propagation mechanism. Light and cryo-electron microscopy show that synthetic seeds nucleate and enhance mutant huntingtin aggregation. This seeding assay distinguishes HD subjects from healthy and non-HD dementia controls without overlap (blinded samples). Ultimately, this seeding property in HD patient CSF may form the basis of a molecular biomarker assay to monitor HD and evaluate therapies that target mHTT

Data Descriptor : A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins

Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment.Peer reviewe

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4°C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature