First global approach: morphological and biological variability in a genetically homogeneous population of the European pilchard, Sardina pilchardus (Walbaum, 1792) in the North Atlantic coast

The European pilchard Sardina pilchardus represents the most commercially relevant fisheries resource in many countries bordering north Atlantic coasts and the Mediterranean Sea, being especially significant along the coast of Morocco. The continuous exploitation of this pelagic species for several decades places Morocco as the leader in sardine production. However, the conditions of exploitation of this resource underwent a great change during the last recent years. In order to identify the populations of the European pilchard sardine (Sardina pilchardus, Walbaum, 1792) in the Atlantic coast of Morocco and Spain, we have combined the truss network data to conduct multivariate analysis with biologic parameters and genetic analysis based on Microsatellite and mitochondrial control region data. Sardine morphometrics data truss variables from 10 samples spanning the Atlantic coast of Morocco were analysed by multivariate analysis. Thirteen morphometric measurements and some biological parameters such as the sex and the age of fishes were made for each individual. Discriminant analysis on size-corrected truss variables and cluster analysis of mean fishes shape using landmark data indicate, that the shape of north Moroccan sardines is distinct from the shape of sardines from south Morocco. However the analysis of the mitochondrial region and four microsatellites loci (Sp2, Sp7, Sp8 and SpI5) demonstrated an homogeneity population in the Moroccan Atlantic coast, with a low but significant genetic differentiation, which followed an isolation-by-distance pattern according to Mantel test.     

Potential of Artesunate in the treatment of visceral leishmaniasis in dogs naturally infected by Leishmania infantum: Efficacy evidence from a randomized field trial

Leishmaniasis is among the world’s most neglected diseases. Dogs are the main reservoirs/hosts of Leishmania infantum, causative agent of both canine and human visceral leishmaniosis. Canine leishmaniasis (CanL) represents a public health problem as one of the most prevalent zoonotic diseases worldwide. Current therapeutics present drawbacks; thus, there is a need for more effective, safer, and cheaper drugs. The aim of this study was to evaluate and to compare the efficacy of oral administration of artesunate or meglumine antimoniate/allopurinol in dogs with clinical leishmaniasis. Forty-two dogs with naturally occurring clinical leishmaniasis were included in this open-label, simple randomized positive-control clinical field trial with 6 months of follow-up. Dogs received meglumine antimoniate 100 mg/kg/day and allopurinol 30 mg/kg/day for 28 days (control group, n = 26) or artesunate 25 mg/kg/day for 6 days (test group, n = 16). The animals were evaluated for their clinical evolution, parasite load (by qPCR) and humoral response at different time points: 0, 30, 90, and 180 days after treatment. Data analyses showed a significant improvement in both groups in clinical scores, parasitemia and antibody titers after treatment. Compared to the control group, the artesunate group showed significantly lower clinical score (P = 0.0001), lower parasitemia (P = 0.0001) and antibody titers after 6 months of follow-up. Compared to baseline values, a rapid, significant reduction (P < 0.012) in antibody levels, 2.28- versus 3.04-fold for the control versus artesunate groups, respectively, was observed 30 days after treatment. Antibody levels continued to decrease further in the artesunate group, where 58% of cases became seronegative at the 6-month follow-up. All qPCR-positive dogs were negative after treatment with artesunate, while 14.3% remained positive with the appearance of two new cases in the control group. Artesunate was well tolerated, and no side effects were recorded. Treatment failures were similar in both groups with 27.27% (6/22), including 18.18% (4/22) mortality in the control group, versus 26.66% (4/15), including 13.33% (2/15) mortality in the artesunate group. This is the first report showing the potential of artesunate in the treatment of dogs with clinical leishmaniasis. Artesunate showed higher efficacy than the current first-line treatment for CanL without any adverse effects. It could be a good alternative chemotherapy for CanL, and may be considered for further studies in human leishmaniases. Further clinical trials are needed to confirm these findings, to determine if there are relapses after treatment and if dogs remain infective to sandflies, to define the ideal therapeutic dosage and duration of treatment with artesunate.     

Effect of subchronic exposure to malathion on metabolic parameters in the rat

This study investigates the effects of subchronic exposure to organophosphate insecticide Malathion (Fyfanon 50 EC 500 g/l) of commercial grade. It was administered intragastrically by stomach tube in the amount of 1 ml of corn oil containing 100 mg/kg body weight (BW) daily for 32 days. At the end of the experiment, acetylcholinesterase activity (AChE), haematocrit value, haemoglobin content, and blood glucose concentration were estimated. The liver and the skeletal muscle were removed to determine hepatic and muscular glycogen, hepatic proteins and lipids contents. No sign of toxicity was observed until the end of experiment. No significant change in the haematocrit value was observed, in spite of the significant increase in haemoglobin content, which can be considered as an adaptive situation in order to guarantee a good oxygenation in response to pulmonary damage induced following subchronic exposure to organophosphorus compound. Malathion intoxication decreased significantly hepatic proteins and lipid contents that could be associated to liver gluconeogenesis. This result was coupled with a significant decrease in muscular glycogen rate, which indicates a stimulated glycogenolysis in favour of glucose release into the blood until reaching hyperglycaemia. Several studies indicate that hyperglycaemia is temporary, which is probably due to a stimulated glycogenesis that increases hepatic glycogen deposition and return of glucose to control levels, as demonstrated in our study. One possible explanation for these results could be the turnover of glucose by a succession between its release via glycogenolysis and gluconeogenesis, which involves abnormal hyperglycaemia, and its storage via glycogenesis in subchronic exposure to malation.     

Oral immunization of mice with engineered Lactobacillus gasseri NM713 strain expressing Streptococcus pyogenes M6 antigen

The aim of this in vivo study was to evaluate the effects of a recombinant probiotic strain, Lactobacillus gasseri NM713, which expresses the conserved region of streptococcal M6 protein (CRR6), as an oral vaccine against Streptococcus pyogenes. A dose of 10⁹ cells of the recombinant strain in 150 μL PBS buffer was administered orally to a group of mice. One control group received an equivalent dose of Lb. gasseri NM613 (containing the empty plasmid without insert) or and another control group received PBS buffer. Each group contained 30 mice. The immunization protocol was followed on three consecutive days, after which two booster doses were administered at two week intervals. Fecal and serum samples were collected from the mice on Days 18, 32, 46, 58 after the first immunization and Day 0 prior to immunization. Anti‐CRR6 IgA and IgG concentrations were measured by ELISA in fecal and sera samples, respectively, to assess immune responses. Vaccination with the recombinant Lb. gasseri NM713 strain induced significant protection after nasal challenge with S. pyogenes, only a small percentage of this group developing streptococcal infection (10%) or dying of it (3.3%) compared with the NM613 and PBS control groups, high percentages of which developed streptococcal infection (43.3% and 46.7%, respectively) and died of it (46.7% and 53%, respectively). These results indicate that recombinant Lb. gasseri NM713 has potential as an oral delivery vaccine against streptococcus group A.     

Melatonin Improves Memory Deficits in Rats with Cerebral Hypoperfusion,Possibly, Through Decreasing the Expression of Small-Conductance Ca2+-Activated K+ Channels

Neurochemical Research - This study investigated the expression pattern, regulation of expression, and the role of hippocampal small-conductance Ca2+-activated K+ (SK) channels in memory deficits...     

Physiological and biochemical studies on Egyptian fresh water algae

Summary The influence of some culture conditions on the growth and protein synthesis by an Egyptian strain of Chlorella ellipsoidea was investigated. It was established that the protein synthesis by this organism was greatly influenced by the variation of such conditions. It was possible to determine the most favourable conditions for growth and protein synthesis.     

Potential of biosynthesized zinc oxide nanoparticles to control Fusarium wilt disease in eggplant (Solanum melongena) and promote plant growth

BioMetals - In this study, a novel, non-toxic, eco-friendly zinc oxide nanoparticles (ZnO-NPs) was used instead of the synthetic fungicides widely used to control the destructive phytopathogenic...     

Alnus peptides modify membrane porosity and induce the release of nitrogen-rich metabolites from nitrogen-fixing Frankia

Actinorhizal plant growth in pioneer ecosystems depends on the symbiosis with the nitrogen-fixing actinobacterium Frankia cells that are housed in special root organs called nodules. Nitrogen fixation occurs in differentiated Frankia cells known as vesicles. Vesicles lack a pathway for assimilating ammonia beyond the glutamine stage and are supposed to transfer reduced nitrogen to the plant host cells. However, a mechanism for the transfer of nitrogen-fixation products to the plant cells remains elusive. Here, new elements for this metabolic exchange are described. We show that Alnus glutinosa nodules express defensin-like peptides, and one of these, Ag5, was found to target Frankia vesicles. In vitro and in vivo analyses showed that Ag5 induces drastic physiological changes in Frankia, including an increased permeability of vesicle membranes. A significant release of nitrogen-containing metabolites, mainly glutamine and glutamate, was found in N₂-fixing cultures treated with Ag5. This work demonstrates that the Ag5 peptide is central for Frankia physiology in nodules and uncovers a novel cellular function for this large and widespread defensin peptide family.     

Comparative molecular analysis of evolutionarily distant glyceraldehyde-3-phosphate dehydrogenase from Sardina pilchardus and Octopus vulgaris

The NAD(+)-dependent cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12), which is recognized as a key to central carbon metabolism in glycolysis and gluconeogenesis and as an important allozymic polymorphic biomarker, was purified from muscles of two marine species: the skeletal muscle of Sardina pilchardus Walbaum (Teleost, Clupeida) and the incompressible arm muscle of Octopus vulgaris (Mollusca, Cephalopoda). Comparative biochemical studies have revealed that they differ in their subunit molecular masses and in pI values. Partial cDNA sequences corresponding to an internal region of the GapC genes from Sardina and Octopus were obtained by polymerase chain reaction using degenerate primers designed from highly conserved protein motifs. Alignments of the deduced amino acid sequences were used to establish the 3D structures of the active site of two enzymes as well as the phylogenetic relationships of the sardine and octopus enzymes. These two enzymes are the first two GAPDHs characterized so far from teleost fish and cephalopod, respectively. Interestingly, phylogenetic analyses indicated that the sardina GAPDH is in a cluster with the archetypical enzymes from other vertebrates, while the octopus GAPDH comes together with other molluscan sequences in a distant basal assembly closer to bacterial and fungal orthologs, thus suggesting their different evolutionary scenarios.     

Onset of feeding in juvenile sea urchins and its relation to nutrient signalling

The purple sea urchin, Strongylocentrotus purpuratus, has been the focus of extensive ecological and developmental research over the years. Strongylocentrotus purpuratus larvae transition into the juvenile stage after an extensive planktonic period. The metamorphic transition is characterized by dramatic changes in morphology and physiology of the juvenile compared to the larval form and mechanisms underlying this process, especially the early days post-settlement, remain poorly understood. We used SEM and phalloidin stain analysis as well as whole mount in situ hybridization to gain a detailed understanding of juvenile development in relation to nutrient signalling [insulin-like growth factor (IIS), FoxO (forkhead box, sub-group ‘O’) and TOR (target of rampamycin), also known as IIS/TOR/FoxO signalling]. Our results show that the majority of juvenile feeding features are fully developed only after 8-days of juvenile development, leaving an extensive period of nutritional stress. We found that FoxO gene expression increases during that time period and is localized in juvenile tube feet, potentially associated with sensory structures involved in nutrient signalling. Our data complement existing work on sea urchin juvenile development and shed new light on the perimetamorphic period of Strongylocentrotus purpuratus, with respect to nutrient signalling and the potential stressful pre-feeding period of juvenile sea urchins.