Effect of the Aegean Sea barrier between Europe and Asia on differentiation in Juniperus drupacea (Cupressaceae)

Juniperus drupacea is an eastern Mediterranean mountain tree with a disjunct geographical range. We hypothesized that this disjunct occurrence (the Peloponnese in Europe and the Taurus and Lebanon Mountains in Asia) should be reflected in the patterns of genetic and morphological diversity and differentiation. Nuclear microsatellite markers (nSSR) and biometric variables of the cones and seeds were examined on material sampled from four populations in Europe and eight in Asia. The Asian populations were characterized by a higher level of genetic diversity than the European populations. The genetic differentiation among populations was moderate but significant (F_ST = 0.101, P < 0.001). According to the clustering performed with BAPS, six genetically and geographically groups of populations were found: I and II from the Peloponnese; III from the Taurus Mountains; IV and V from the Anti‐Taurus Mountains; and VI from the Lebanon Mountains. The level of genetic differentiation among these six groups (4.30%, P = 0.012) probably reflects long‐lasting genetic isolation during the Pleistocene, as limited genetic admixture was found. In accordance with genetic analysis, the biometric investigations indicated a high level of morphological divergence between the European and Asian populations of the species, with further differentiation between the populations from the Taurus and Lebanon Mountains.     

Quantitative determination of latrunculins A and B in the Red Sea sponge Negombata magnifica by high performance liquid chromatography

An accurate, reproducible and sensitive method for the quantitative determination of latrunculins A and B in the organic extract of the Red Sea sponge Negombata magnifica was developed and validated. Latrunculin A and B concentrations were determined by RP-C18-HPLC and a mobile phase consisting of acetonitrile and water (60:40, v/v). The flow rate utilized was 1 mL min(-1) and the detector was set at 235 nm. The HPLC analysis of several N. magnifica samples collected from different locations in the Red Sea revealed that Ras Mohamed had the highest concentrations of latrunculin A, while Safaga had the highest levels of latrunculin B. Also, a comparison between latrunculin concentrations in the summer and winter revealed that the yield of latrunculins were generally higher in the winter.     

Dopamine neurons implanted into people with Parkinson's disease survive without pathology for 14 years

Postmortem analysis of five subjects with Parkinson's disease 9-14 years after transplantation of fetal midbrain cell suspensions revealed surviving grafts that included dopamine and serotonin neurons without pathology. These findings are important for the understanding of the etiopathogenesis of midbrain dopamine neuron degeneration and future use of cell replacement therapies.     

State-sensitive monitoring of gold nanoparticle sites on titania and the interaction of the positive Au site with O2 by Au Lα1-selecting X-ray absorption fine structure

The heterogeneity of gold sites in various Au/TiO₂ catalysts was studied by means of state-sensitive Au L₃-edge X-ray absorption fine structure (XAFS) combined with high energy-resolution X-ray fluorescence spectrometry. A series of Au/TiO₂ catalysts were prepared via deposition-precipitation method on anatase-type or mesoporous (amorphous) TiO₂ added with NaOH (lower Au loading) or urea (higher Au loading). The mean Au particle size ranged between 29 and 87 Å based on high-resolution TEM (transmission electron microscope) measurements. The Au Lα₁ emission peak energy for Au/mesoporous-TiO₂ in air and Au/anatase-TiO₂ in CO (5%) corresponded to Au⁰ state. The emission peak energy for Au/anatase-TiO₂ in air shifted toward that of Au^I state. For relatively greater Au particles (average 87 Å) dispersed on mesporous TiO₂, the major valence state discriminated by Au Lα₁-selecting XANES (X-ray absorption near-edge structure) spectrum tuned to Au Lα₁ emission peak top was Au⁰, but the Au^δ− state could be successfully monitored by Au Lα₁-selecting XANES tuned to the emission energy at 9707.6 eV, of which population was relatively small compared to the case of smaller Au particles (average 29 Å) on anatase-type TiO₂. On the other hand, negative charge transfer from Au 5d to support was demonstrated in Au^δ+-state sensitive XANES tuned to 9718.3-9718.7 eV. The Au^δ+-state sensitive XANES spectra resembled theoretically generated XANES for interface Au^δ+ sites model on TiO₂ in contact with surface Ti sites. Further charge transfer was demonstrated from Au to adsorbed O₂ for Au/anatase-TiO₂ catalyst.     

Small neutralizing molecules to inhibit actions of the chemokine CXCL12

The chemokine CXCL12 and the receptor CXCR4 play pivotal roles in normal vascular and neuronal development, in inflammatory responses, and in infectious diseases and cancer. For instance, CXCL12 has been shown to mediate human immunodeficiency virus-induced neurotoxicity, proliferative retinopathy and chronic inflammation, whereas its receptor CXCR4 is involved in human immunodeficiency virus infection, cancer metastasis and in the rare disease known as the warts, hypogammaglobulinemia, immunodeficiency, and myelokathexis (WHIM) syndrome. As we screened chemical libraries to find inhibitors of the interaction between CXCL12 and the receptor CXCR4, we identified synthetic compounds from the family of chalcones that reduce binding of CXCL12 to CXCR4, inhibit calcium responses mediated by the receptor, and prevent CXCR4 internalization in response to CXCL12. We found that the chemical compounds display an original mechanism of action as they bind to the chemokine but not to CXCR4. The highest affinity molecule blocked chemotaxis of human peripheral blood lymphocytes ex vivo. It was also active in vivo in a mouse model of allergic eosinophilic airway inflammation in which we detected inhibition of the inflammatory infiltrate. The compound showed selectivity for CXCL12 and not for CCL5 and CXCL8 chemokines and blocked CXCL12 binding to its second receptor, CXCR7. By analogy to the effect of neutralizing antibodies, this molecule behaves as a small organic neutralizing compound that may prove to have valuable pharmacological and therapeutic potential.     

Residual embryonic cells as precursors of a Barrett's-like metaplasia

Barrett's esophagus is an intestine-like metaplasia and precursor of esophageal adenocarcinoma. Triggered by gastroesophageal reflux disease, the origin of this metaplasia remains unknown. p63-deficient mice, which lack squamous epithelia, may model acid-reflux damage. We show here that p63 null embryos rapidly develop intestine-like metaplasia with gene expression profiles similar to Barrett's metaplasia. We track its source to a unique embryonic epithelium that is normally undermined and replaced by p63-expressing cells. Significantly, we show that a discrete population of these embryonic cells persists in adult mice and humans at the squamocolumnar junction, the source of Barrett's metaplasia. We show that upon programmed damage to the squamous epithelium, these embryonic cells migrate toward adjacent, specialized squamous cells in a process that may recapitulate early Barrett's. Our findings suggest that certain precancerous lesions, such as Barrett's, initiate not from genetic alterations but from competitive interactions between cell lineages driven by opportunity.     

Influences of total sulfur amino acids and photoperiod on growth,carcass traits,blood parameters,meat quality and cecal microbial load of broilers

The current study aimed to discuss the impact of total sulfur amino acids (TSAA) %, photoperiod, and their interaction on growth performance, carcass and blood indices of broiler chicks. A total of 300 unsexed IR broiler chicks one-week old were used in a factorial arrangement (2 × 3), including two photoperiod systems (22 L: 2 D and 16 L: 8 D) and three experimental rations having three grades of Met + Cyst (TSAA) (70%, 85% and 100% of digestible lysine in starter and finisher diets). Results revealed that the higher LBW and BWG were noticed in birds given TSAA at grades of 1.1 or 0.90 % under 22L: 2D photoperiod at five weeks of age and the whole experimental period (1–5 weeks of age), respectively. The highest live body weight (LBW (and body weight gain (BWG) were recorded in birds received 1.1% TSAA under the long photoperiod compared to the control and the other groups. Birds fed 1.3% TSAA consumed more feed than the other groups. The opposite was found in birds fed 1.1% TSAA under the short photoperiod (16L: 8D). The best feed conversion (FCR) was detected by birds fed 1.1% and 0.90% TSAA diets during the whole experimental period. All carcass traits studied were significantly influenced by TSAA levels, except for the relative weights of abdominal fat and spleen. The interaction effect on was significant on all carcass traits except spleen %. In conclusion, the addition of TSAA at level 1.1 and 0.9 % to starter and finisher diets under a long photoperiod regime improved broiler’s performance, carcass traits, and blood parameters studied.