Building a biomimetic membrane for neutron reflectivity investigation : complexity, asymmetry and contrast

The preparation and investigation of model membranes is deserving growing interest both for the physics of complex systems, and for biology. The need of simplified models should preserve mimicking the qualifying characteristics of biological membranes, and keep non-invasive and detailed description. As a main feature, biological membranes are non-homogeneous in the disposition of components, both in the lateral and in the transverse direction. We prepared asymmetric supported membranes containing GM1 ganglioside in biomimetic proportion according to different protocols. Then, we studied their internal structure by neutron reflectometry, providing few-Angstrom sensitivity in the cross direction meanwhile avoiding radiation damage. This technique can also be profitably applied to study interactions at the membrane surface. The best protocol has proven to be the Langmuir-Blodgett/Langmuir-Schaefer depositions. Notably, also the simpler and most accessible protocol of vesicle fusion was found to be suitable for straightforward and good quality deposition of compositionally asymmetric membranes

Geoelectrical Subsurface Characterization for Foundation Purposes in the College of Agricultural Sciences (CAS) Campus, Ebonyi State University, Abakaliki, Southeastern Nigeria

The study area is underlain by shales and volcanoclastics with subordinate lenses of sandstones and sandy limestone (Abakaliki Formation) of the Albian Asu River Group, southeastern Nigeria. Geophysical investigation was carried out at the College of Agricultural Sciences (CAS) Campus, Ebonyi State University (EBSU) to determine the structural competence of the subsurface geological strata for building construction and other foundation purposes, using vertical electrical sounding (VES) survey technique of the electrical resistivity method. From the result of the survey, two major zones have been established within the study area for building construction purposes. Zone A comprises of areas around the catholic church building, EBSU primary school up to the school of post graduate studies, while zone B  is made up of areas around the EBSU secondary school, proposed student centre up to the main entrance gate which led to the Ogoja road. Zone A has been recommended for bungalows and other forms of low rising buildings, while zone B has been recommended for storey buildings and other heavy engineering structures. Overburden thickness for the two zones ranges from 1.3 m to 2.7 m, and 0.6 m to 2.7 m for zones A and B respectively. The cracks on walls of the buildings within the campus have been attributed to either the inability of the engineers to dig the foundation to the required depth or the construction of heavier structures on very weak subsurface layers which triggered off movement. Keywords: Geoelectrical, Characterization, Foundation, Ebonyi State University, Nigeria

RELATION BETWEEN MATERNAL THROMBOPHILIA AND STILLBIRTH ACCORDING TO CAUSES/ASSOCIATED CONDITIONS OF DEATH

OBJECTIVE: To investigate maternal thrombophilia in cases of Stillbirth (SB), also an uncertain topic because most case series were not characterised for cause/associated conditions of death. STUDY DESIGN: In a consecutive, prospective, multicentre design, maternal DNA was obtained in 171 cases of antenatal SB and 326 controls (uneventful pregnancy at term, 1:2 ratio). Diagnostic work-up of SB included obstetric history, neonatologist inspection, placenta histology, autopsy, microbiology/chromosome evaluations. Results audited in each centre were classified by two of us by using CoDAC. Cases were subdivided into explained SB where a cause of death was identified and although no defined cause was detected in the remnants, 64 cases found conditions associated with placenta-vascular disorders (including preeclampsia, growth restriction and placenta abruption - PVD). In the remnant 79 cases, no cause of death or associated condition was found. Antithrombin activity, Factor V Leiden, G20210A Prothrombin mutation (FII mutation) and acquired thrombophilia were analysed. RESULTS: Overall, the presence of a thrombophilic defect was significantly more prevalent in mothers with SBs compared to controls. In particular, SB mothers showed an increased risk of carrying Factor II mutation (OR=3.2, 95\% CI: 1.3-8.3, p=0.01), namely in unexplained cases. Such mutation was significantly associated also with previous SB (OR=8.9, 95\%CI 1.2-70.5). At multiple logistic regression, Factor II mutation was the only significantly associated variable with SB (adj OR=3.8, 95\% CI: 1.3-13.5). CONCLUSION: These data suggest that Factor II mutation is the only condition specifically associated with unexplained SB and could represents a risk of recurrence. PVD-associated condition is unrelated to thrombophilia

Syndecan expressions in the human amnion and chorionic plate

The syndecan family consists of four distinct membrane glycoproteins in mammals. Syndecans control cell proliferation, differentiation, adhesion and migration through participation in cell-cell interactions, anchorage of cells to the extracellular environment, and modulation of multiple growth factors. Therefore, syndecans may play a pivotal role in the regulation of cell behaviour depending on the cellular microenvironment. Here, we demonstrate that syndecan-1, syndecan-2 and syndecan-4 are expressed in fetal membrane tissue with different immunolocalizations. Syndecan-1 is expressed in the amniotic epithelium, localizing at basolateral cell surfaces. Syndecan-2 and syndecan-4, in contrast, are mostly localized in intracellular compartments, in the extravillous cytotrophoblastic cells and in some fibroblasts of the chorionic plate as well as in the amniotic epithelial cells. In the latter, syndecan-4 is mainly localized in the apical part of the cells. Our results strongly suggest a key role of syndecan-1, syndecan-2 and syndecan-4 in the determination of structural and functional characteristics of human amnion and chorionic plate. Since the solute exchanges between fetus and mother take place in fetal membranes, our data suggest that syndecans are important players in the placenta for the establishment of the fetal-maternal inter-communication

Prediction of preterm birth with and without preeclampsia using mid-pregnancy immune and growth-related molecular factors and maternal characteristics.

OBJECTIVE:To evaluate if mid-pregnancy immune and growth-related molecular factors predict preterm birth (PTB) with and without (±) preeclampsia. STUDY DESIGN:Included were 400 women with singleton deliveries in California in 2009-2010 (200 PTB and 200 term) divided into training and testing samples at a 2:1 ratio. Sixty-three markers were tested in 15-20 serum samples using multiplex technology. Linear discriminate analysis was used to create a discriminate function. Model performance was assessed using area under the receiver operating characteristic curve (AUC). RESULTS:Twenty-five serum biomarkers along with maternal age <34 years and poverty status identified >80% of women with PTB ± preeclampsia with best performance in women with preterm preeclampsia (AUC = 0.889, 95% confidence interval (0.822-0.959) training; 0.883 (0.804-0.963) testing). CONCLUSION:Together with maternal age and poverty status, mid-pregnancy immune and growth factors reliably identified most women who went on to have a PTB ± preeclampsia

Vitamin D responsive elements within the HLA-DRB1 promoter region in Sardinian multiple sclerosis associated alleles

Vitamin D response elements (VDREs) have been found in the promoter region of the MS-associated allele HLA-DRB1*15:01, suggesting that with low vitamin D availability VDREs are incapable of inducing *15:01 expression allowing in early life autoreactive T-cells to escape central thymic deletion. The Italian island of Sardinia exhibits a very high frequency of MS and high solar radiation exposure. We test the contribution of VDREs analysing the promoter region of the MS-associated DRB1 *04:05, *03:01, *13:01 and *15:01 and non-MS-associated *16:01, *01, *11, *07:01 alleles in a cohort of Sardinians (44 MS patients and 112 healthy subjects). Sequencing of the DRB1 promoter region revealed a homozygous canonical VDRE in all *15:01, *16:01, *11 and in 45/73 *03:01 and in heterozygous state in 28/73 *03:01 and all *01 alleles. A new mutated homozygous VDRE was found in all *13:03, *04:05 and *07:01 alleles. Functionality of mutated and canonical VDREs was assessed for its potential to modulate levels of DRB1 gene expression using an in vitro transactivation assay after stimulation with active vitamin D metabolite. Vitamin D failed to increase promoter activity of the *04:05 and *03:01 alleles carrying the new mutated VDRE, while the *16:01 and *03:01 alleles carrying the canonical VDRE sequence showed significantly increased transcriptional activity. The ability of VDR to bind the mutant VDRE in the DRB1 promoter was evaluated by EMSA. Efficient binding of VDR to the VDRE sequence found in the *16:01 and in the *15:01 allele reduced electrophoretic mobility when either an anti-VDR or an anti-RXR monoclonal antibody was added. Conversely, the Sardinian mutated VDRE sample showed very low affinity for the RXR/VDR heterodimer. These data seem to exclude a role of VDREs in the promoter region of the DRB1 gene in susceptibility to MS carried by DRB1* alleles in Sardinian patients

Characterization of the maintained vegetative phase deletions from diploid wheat and their effect on VRN2 and FT transcript levels

Allelic differences at the VRN1 (AP1/CAL/FRU), VRN2 (ZCCT) and VRN3 (FT) vernalization genes affect flowering time in wheat. The two maintained vegetative phase (mvp) mutants from Triticummonococcum L., previously reported as carrying a single gene (VRN1) deletion, are incapable of flowering. In this study, we show that both mvp lines have larger deletions that include the genes AGLG1, CYS, PHYC, VRN1 and possibly others. The original mvp deletions were generated in lines that lack the VRN2 gene. Therefore, to study the effect of the mvp deletions on the regulation of VRN2 we generated populations segregating for both genes simultaneously. The two mvp deletions co-segregated with the non-flowering phenotype, but surprisingly, the lines homozygous for the mvp mutations showed reduced transcript levels of both VRN2 and FT relative to the wild type. The VRN1 deletion is an unlikely cause of the down-regulation of VRN2 since VRN2 transcript levels are higher in the fall, before VRN1 is expressed, and are down-regulated by VRN1. Since both VRN2 and FT are regulated by light and photoperiod, their down-regulation in the mvp mutants might be related to the deletion of the PHYC photoreceptor. However, alternative hypotheses including combinations of other genes deleted in the mvp mutants cannot be ruled out. Until the specific gene(s) responsible for the down-regulation of VRN2 and FT and the non-flowering phenotype are precisely identified, it is premature to use these results to postulate alternative flowering models