Circulating miRNAs expression as potential biomarkers of mild traumatic brain injury

Molecular Biology Reports - TBI is the main cause of death and disability in individuals aged 1–45 in Western countries. One of the main challenges of TBI at present is the lack of specific...     

VKORC1L1, an Enzyme Rescuing the Vitamin K 2,3-Epoxide Reductase Activity in Some Extrahepatic Tissues during Anticoagulation Therapy

Vitamin K is involved in the γ-carboxylation of the vitamin K-dependent proteins, and vitamin K epoxide is a by-product of this reaction. Due to the limited intake of vitamin K, its regeneration is necessary and involves vitamin K 2,3-epoxide reductase (VKOR) activity. This activity is known to be supported by VKORC1 protein, but recently a second gene, VKORC1L1, appears to be able to support this activity when the encoded protein is expressed in HEK293T cells. Nevertheless, this protein was described as being responsible for driving the vitamin K-mediated antioxidation pathways. In this paper we precisely analyzed the catalytic properties of VKORC1L1 when expressed in Pichia pastoris and more particularly its susceptibility to vitamin K antagonists. Vitamin K antagonists are also inhibitors of VKORC1L1, but this enzyme appears to be 50-fold more resistant to vitamin K antagonists than VKORC1. The expression of Vkorc1l1 mRNA was observed in all tissues assayed, i.e. in C57BL/6 wild type and VKORC1-deficient mouse liver, lung, and testis and rat liver, lung, brain, kidney, testis, and osteoblastic cells. The characterization of VKOR activity in extrahepatic tissues demonstrated that a part of the VKOR activity, more or less important according to the tissue, may be supported by VKORC1L1 enzyme especially in testis, lung, and osteoblasts. Therefore, the involvement of VKORC1L1 in VKOR activity partly explains the low susceptibility of some extrahepatic tissues to vitamin K antagonists and the lack of effects of vitamin K antagonists on the functionality of the vitamin K-dependent protein produced by extrahepatic tissues such as matrix Gla protein or osteocalcin.     

Evidence of gene flow between sympatric populations of the Middle East‐Asia Minor 1 and Mediterranean putative species of Bemisia tabaci

Bemisia tabaci is a complex of putative species that exhibit a strong geographical pattern. Crossing experiments have revealed various degrees of reproductive isolation between these nascent species, ranging between fertile first‐generation hybrids (F1) and no F1 at all. However, the relevance of these results under natural conditions is generally not known. The worldwide invasion of the putative species Middle East‐Asia Minor 1 (MEAM1) has caused secondary contacts between allopatric species, which in turn provide an opportunity to detect potential hybrids in nature. A total of 346 female B. tabaci were collected in 2003 and 2005 in the North East of Morocco and assigned to MEAM1 (119), Mediterranean (Med) (225) and a new putative species (2) using mitochondrial cytochrome oxidase (mtCOI) gene sequences. MEAM1 and Med individuals were characterized at seven microsatellite loci. MEAM1 and Med were found to be sympatric in 11 of 12 samples (6 fields/year). As previously reported from Spain, MEAM1 frequency decreased over time. The genetic data are consistent with a recent introduction of MEAM1. A Bayesian clustering analysis (Structure ) distinguished two groups, which were 100% consistent with the mtCOI groups. From several lines of evidence, two individuals were identified as hybrids. Assignment profiles using NewHybrids and allele composition indicated that they were not F1 hybrids. The results are discussed in relation to the secondary endosymbiont infection status determined on a sample of individuals, and the contrasting outcomes of the reported crossing experiments between MEAM1 and Med.     

Sexual size dimorphism and morphometric sexing in a North African population of Laughing Doves Spilopelia senegalensis

Like the majority of Columbiformes, the Laughing Dove Spilopelia senegalensis is sexually monomorphic in plumage, but seems to be slightly dimorphic in size. However, due to the lack of studies little is known about the sexual size dimorphism in this species. In this work, we used morphometric data on a sample of 61 Laughing Doves from southern Tunisia, and sexed using a DNA-based method, to assess size differences between males and females and to determine a discriminant function useful for sex identification. The results showed that wing length was the most dimorphic trait, which could be due to the effects of sexual selection. The best function for the discrimination between sexes included wing length and head length, which is comparable with findings on other dove species. This discriminant function accurately classified 89% of birds, providing a rapid and accurate tool for sex identification in the studied population. Further data from different populations are needed for firmer conclusions about the extent of sexual size dimorphism and the reliability of the morphometric sexing approach in this dove species.     

Physiological, morphological and metabolic changes in Tetrahymena pyriformis for the in vivo cytotoxicity assessment of metallic pollution: Impact on d-β-hydroxybutyrate dehydrogenase

The individual cytotoxicity of cadmium chloride, iron sulphate and chromium nitrate has been investigated by using the freshwater ciliate Tetrahymena pyriformis. The metabolic enzymes and antioxidant defense biomarkers were assessed. The results obtained reveal that their metal salts have perturbed the physiology and morphology of T. pyriformis. Also, the biomarkers assessed were sensitive to the presence of metal salts and this sensitivity was metal salt and dose dependant. To estimate the impact of their metal salts on mitochondria, we studied their effects in vivo and in vitro on the d-β-hydroxybutyrate dehydrogenase (BDH) (EC 1.1.1.30) inner mitochondrial membrane enzyme. The results showed a high inhibition of BDH in terms of activity, protein expression and kinetic parameters.     

Influence of sparkle and saccades on tongue electro-stimulation-based vision substitution of 2D vectors

Vision substitution by electro-stimulation has been studied since the 60s beginning with P. Bach-y-Rita. Camera pictures or movies encoded in gray levels are displayed using an electro-stimulation display device on the surface of a body part, such as the skin or the tongue. Medical-technical devices have been developed on this principle to compensate for sensory-motor disabilities such as blindness or loss of balance, or to guide specific actions, such as surgery. However, the electrical signals of stationary or moving slowly moving objects, displayed on a Tongue display unit (TDU), are quickly lost due to saturation of receptors undergoing electrostimulation. We propose to add random saccades or sparkle to the displayed visual scene to increase the quality of pattern recognition by the subjects. In the present experimental trimodal study (normal vision, TDU vision substitution, or both), we show that the presence of a moderate sparkle level enhances the perception of the direction of lines drawn on a TDU and reduces the response time.     

Influence of pH Control Agents on Entomotoxicity Potency of Bacillus thuringiensis using Different Raw Materials

Summary In this investigation, ammonium hydroxide and acetic acid were used as pH control agents during Bacillus thuringiensis (Bt) fermentation in a pilot scale fermentor (150-l) employing two secondary wastewater sludges from two different wastewater treatment plants (CUQS and JQS) and semi-synthetic soybean meal medium as raw materials. Regardless of the cultivation medium, a substantial increase in total cell count, spore count, protease activity and entomotoxicity was achieved when the pH of the culture was controlled using NH₄OH/CH₃COOH. At harvest, total cell count increased by almost 17%, 33% and 25%; protease activity was enhanced by 12%, 33% and 53% and maximal spore count augmented by almost 28%, 48% and 33% in CUQS, JQS and soybean medium, respectively. Entomotoxicity potency was improved by 22%, 21% and 14% in CUQS, JQS and soybean medium, respectively compared to results obtained with NaOH/H₂SO₄ as pH control agents. A higher entomotoxicity was also observed using sludge compared to the soybean medium. This improvement of the Bt process performance was a consequence of the addition of rapidly utilizable carbon and nitrogen source through pH control, which stimulated endotoxin production in the crystal and enhanced sporulation.     

Wintering waterbird assemblages in the central part of the Gulf of Gabès in southern Tunisia

Although the Gulf of Gabès is recognised as an Important Bird Area, several aspects of the ecology of waterbirds inhabiting this area still need to be investigated. We observed how waterbird foraging guilds varied among habitats. In total, 49 species belonging to 16 families were recorded. Winter visitors accounted for 73% of counts. The avifauna was dominated by shorebirds (52% of records), followed by large wading birds (25%), open-water birds (18%) and waterfowl (5%). However, the structure of local waterbird communities and their composition in terms of foraging guilds varied according to habitat type. The bird communities of sandy beaches were dominated by open-water birds, whereas large mudflats were dominated by shorebirds, and wadi estuaries showed a more even representation of foraging guilds. Locally rare species had narrow distributions, whereas locally abundant species were found widely within the gulf. For four species the 1% population level criterion of the Ramsar Convention was exceeded. Overall, our results show that the Gulf of Gabès hosts important numbers of waterbirds with different ecological requirements, which confirms the importance of this gulf as a wintering area for Palearctic waterbirds.     

Effect of napping opportunity at different times of day on vigilance and shuttle run performance

ABSTRACT

The aim of the present study was to examine the effect of a nap opportunity during the daytime realized at different times of day on physical and mental performance. Eighteen physically active males (age: 20.5 ± 3.0 years, height: 175.3 ± 5.9 cm, body-mass: 70.0 ± 8.6 kg) were tested under four experimental conditions: no-nap condition, nap at 13h00, nap at 14h00 and nap at 15h00. All nap durations were of 25-min and all tests were performed at 17h00. They performed a 5-m shuttle run test, which generated measures of the highest distance (HD) and total distance (TD). The rating of perceived exertion (RPE) was recorded after each of the six sprints in the 5-m shuttle run test. Vigilance was measured using a digit cancellation test. The results showed that TD at 17h00 was 4% greater after a nap at 14h00 than in the no-nap condition (+28 m, p < .05) or after the nap at 13h00 (+29 m, p < .05). HD was 8% higher (+9 m, p < .001) after a nap at 14h00 than in the no-nap condition and 7% higher after nap at 15h00 than in the no-nap condition (+7 m, p < .05). In addition, HD was 6% higher after nap at 14h00 (+7 m, p < .01) and 5% higher after nap at 15h00 (+9 m, p < .01) than HD after a nap at 13h00. Napping at 13h00 had no effect on physical performance at 17h00. No significant differences were observed between RPE and vigilance scores in the nap and no-nap conditions. In conclusion, napping for 25 min at 14h00 and 15h00 produces meaningful improvements in responses during repeated short-term maximal exercise tests performed at 17h00. Napping at 13h00 does not. Vigilance, as measured using a digit cancellation test, and RPE scores are not influenced by any of the nap opportunities.