Establishment of reference values for the lysine acetylation marker Nɛ-acetyllysine in small volume human plasma samples by a multi-target LC–MS/MS method

Amino Acids - Cardiovascular disease (CVD) and chronic kidney disease (CKD) constitute substantial burdens for public health. The identification and validation of risk markers for CVD and CKD in...     

Évolution du trait de côte à l’Holocène supérieur dans la Sebkha El-Guettiate de Skhira (Golfe de Gabès, Tunisie) à travers sa faune d’ostracodes et de foraminifères

A 122 cm-long core was taken in the El-Guettiate Sebkha of Skhira (southeastern part of Tunisia) in order to investigate the recent palaeoenvironmental evolution of this region. The quantitative and qualitative analysis of ostracod and benthic foraminifera assemblages coupled with a correspondence analysis allows the reconstruction of palaeoenvironmental changes during the Holocene in this area. Four typical associations of ostracods (open marine, coastal marine, lagoonal and estuarine brackish) and two associations of benthic foraminifera (coastal and lagoonal) were distinguished. The onset of restricted lagoonal environments linked to the building-up of sand spit led to the onset of restricted lagoon and brackish environment at cal. 5408 years BP. The Shannon and equitability index of diversity were used to decipher the structural variations of the populations of ostracods and benthic foraminifera along the sampled core. We note a reduction in the Shannon index from the bottom to the top, which indicates a progressive isolation of the biotope. The open lagoonal episode is characterized by high values of diversity. During restricted lagoonal episodes the Shannon and equitability index are reduced. The correspondence analysis reveals an environmental gradient related to the marine influence. It shows an antagonism between the widely opened estuarian lagoonal species and those of restricted lagoon. The less opened estuarian lagoonal taxa occupy an intermediate position. Based on these evidences, microfauna carried out in the El-Guettiate Sebkha allows us to recognize four phases beginning with a widely opened estuarian lagoon (ca. cal. 7460 years PB), followed by a restricted lagoon (ca. cal. 5408 years BP) and finally a brackish lagoon evolving towards the present-day sebkha environment. The opened estuarine lagoon is characterized by high values of species richness and diversity indices.     

Vasopressin Inhibits LTP in the CA2 Mouse Hippocampal Area

Growing evidence points to vasopressin (AVP) as a social behavior regulator modulating various memory processes and involved in pathologies such as mood disorders, anxiety and depression. Accordingly, AVP antagonists are actually envisaged as putative treatments. However, the underlying mechanisms are poorly characterized, in particular the influence of AVP on cellular or synaptic activities in limbic brain areas involved in social behavior. In the present study, we investigated AVP action on the synapse between the entorhinal cortex and CA2 hippocampal pyramidal neurons, by using both field potential and whole-cell recordings in mice brain acute slices. Short application (1 min) of AVP transiently reduced the synaptic response, only following induction of long-term potentiation (LTP) by high frequency stimulation (HFS) of afferent fibers. The basal synaptic response, measured in the absence of HFS, was not affected. The Schaffer collateral-CA1 synapse was not affected by AVP, even after LTP, while the Schaffer collateral-CA2 synapse was inhibited. Although investigated only recently, this CA2 hippocampal area appears to have a distinctive circuitry and a peculiar role in controlling episodic memory. Accordingly, AVP action on LTP-increased synaptic responses in this limbic structure may contribute to the role of this neuropeptide in controlling memory and social behavior.     

Evolution of the sebkha Dreîaa (South-Eastern Tunisia,Gulf of Gabes) during the Late Holocene: Response of ostracod assemblages

The quantitative and qualitative study of the ostracod assemblages supported by the correspondence analysis (CA) allowed the reconstruction of the palaeoenvironnemental change during the Holocene in the sebkha Dreîaa of Skhira (Gulf of Gabes, SE Tunisia). Five phases were distinguished: the first phase (> cal. 6471–6874 yr BP) coincides with the first Holocene marine transgression following the deposition of the continental Holocene series. It induces the setting of an open lagoon where numerous Bivalvia, Gastropoda and marine ostracods lived. The second one (cal. 6471–6874 yr BP) is characterized by the development of brackish ostracods, high diversity index values and comparable percentages of the brackish, lagoonal and coastal assemblages. It corresponds to an open lagoon subjected to estuarine influences. During the third phase (cal. 3350–3752 yr BP), a marine environment, marked by the enrichment of marine ostracods, is evolving toward the closing. The settlement of the restricted lagoonal environments is linked to the building-up of sandy spit. At cal. 2839–3057 yr BP, the dominance of coastal ostracods, associated with coarse sands, show an open lagoon and probably a marine transgression evidenced by the progressive modification in the ostracods assemblages. After this transgression, the southern part of Sebkha of Dreîaa emerged and evolved towards the present state. The last phase, cal. 515–777 yr BP, is marked by a strong marine influence, in the northern part of the sebkha, with transport of marine Bivalvia, Gastropoda and ostracods towards the inner lagoon by means of storms. The rupture of sandy spits induced the introduction of marine macrofauna and microfauna which were accumulated and associated with charcoals and coarse sands.     

Mowat-Wilson syndrome in a Moroccan consanguineous family

Mowat-Wilson syndrome is a mental retardation-multiple congenital anomaly syndrome characterized by a typical facies, developmental delay, epilepsy, and variable congenital malformations, including Hirschsprung disease, urogenital anomalies, congenital heart disease, and agenesis of the corpus callosum. This disorder is sporadic and is caused by heterozygous mutations or deletions of the ZFHX1B gene located in the 2q22 region. We report here the first Moroccan patient, born to consanguineous parents, with Mowat-Wilson syndrome, due to a de novo, unreported mutation of the ZFHX1B gene.     

A recurrent mutation in Moroccan patients with Dyggve-Melchior-Clausen syndrome: Report of a new case and review

Dyggve-Melchior-Clausen (DMC) syndrome is a rare autosomal recessive disorder. It is a spondyloepimetaphyseal dysplasia associated with mental retardation. Clinical manifestations include coarse facies, microcephaly, short trunk dwarfism, and mental retardation. Mutations in Dymeclin gene (DYM), mapped to chromosome 18q21.1, is responsible for DMC. We report here the observation of a consanguineous Moroccan patient having DMC syndrome. The molecular studies showed a previously reported homozygous mutation at c.1878delA of DYM gene. We discuss this recurrent mutation in Moroccan patients with DMC syndrome with a review.     

Characterization of a rare short arm heteromorphism of chromosome 22 in a girl with down-syndrome like facies

Chromosomal heteromorphisms are described as interindividual variation of chromosomes without phenotypic consequence. Chromosomal polymorphisms detected include most regions of heterochromatin of chromosomes 1, 9, 16 and Y and the short arms of all acrocentric chromosomes. Here, we report a girl with Down-syndrome such as facies and tremendously enlarged short arm of a chromosome 22. Fluorescence in situ hybridization (FISH) with a probe specific for all acrocentric short arms revealed that the enlargement p arms of the chromosome 22 in question contained exclusively heterochromatic material derived from an acrocentric short arm. Parental studies identified a maternal origin of this heteromorphism. Cryptic trisomy 21 of the Down-syndrome critical region was excluded by a corresponding FISH-probe. Here, we report, to the best of our knowledge, largest ever seen chromosome 22 short arm, being ~×1.5 larger than the normal long arm.