Mutations in SOX18 cause the human hypotrichosis-lymphedema-telangiectasia (HLT) syndrome. Their murine counterparts are the spontaneous ragged mutants, showing combined defects in hair follicle, blood vessel, and lymphatic vessel development. Mice null for Sox18 display only mild coat defects, suggesting a dominant-negative effect of Sox18/ragged mutations and functional redundancy between Sox18 and other Sox-F proteins. We addressed this point in zebrafish. The zebrafish homologs of Sox18 and of Sox7 are expressed in angioblasts and in the endothelial component of nascent blood vessels in embryos. Knockdown of either gene, using moderate doses of specific morpholinos, had minimal effects on vessels. In contrast, simultaneous knockdown of both genes resulted in multiple fusions between the major axial vessels. With combined use of transgenic lines and molecular markers, we could show that endothelial cells are specified, but fail to acquire a correct arteriovenous identity. Venous endothelial cell differentiation was more severely affected than arterial. Thus, sox7 and sox18 play redundant but collectively essential roles in the establishment of proper arteriovenous identity in zebrafish. Our data suggest that a defect in arteriovenous identity could be responsible for the formation of telangiectases in patients with HLT. IntroductionThe acquisition of arterial and venous identity is an early event in endothelial cell differentiation, preceding the onset of blood circulation. Pioneering work in the zebrafish has revealed that the acquisition of arterial identity is governed by a genetic network including Shh, VEGF, and Notch signaling. [1][2][3] Many aspects of this regulatory cascade are also conserved in mammals. 4 More recently, the acquisition of venous identity was shown not to occur by default but rather to be genetically controlled. The orphan nuclear receptor COUP-TFII induces venous endothelial cell differentiation by suppressing Notch signaling. 5 Although chick-quail grafting experiments point to an initial plasticity (ie, nascent endothelial cells are able to change their arteriovenous identity depending on the surrounding context), it is becoming clear that arterial and venous angioblasts segregate from the beginning of vasculogenesis. 6 The ephrin/Eph system is involved in the establishment of arteriovenous (AV) cell identity, and is important for the segregation between arteries and veins. The transmembrane ligand ephrinB2, and its cognate tyrosine kinase receptor EphB4, are exclusively expressed by arterial and venous endothelial cells, respectively, both in mouse and in zebrafish, and this molecular distinction is essential to establish a functional hierarchical vascular network. 6 Arteriovenous malformations (AVMs) are frequently induced by a loss of arterial or venous cell identity. 7 In humans, hereditary hemorrhagic telangiectasia (HHT) is a vascular dysplasia characterized by anomalous fusion of arterioles and venules, leading to telangiectases in the skin and mucocutaneous tissues and in...

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease, and some of its forms are progressive. This study describes the profiling of hepatic gene expression and serum protein content in patients with different subtypes of NAFLD. Liver biopsy specimens from 98 bariatric surgery patients were classified as normal, steatosis alone, steatosis with nonspecific inflammation, and nonalcoholic steatohepatitis (NASH). Microarray hybridizations were performed in triplicate and the microarray expression levels of a selected group of genes were confirmed using real-time quantitative reverse-transcriptase polymerase chain reaction. Serum protein profiles of the same patients were determined by SELDI-TOF mass spectrometry. Of 98 obese patients, 91 were diagnosed with NAFLD (12 steatosis alone, 52 steatosis with nonspecific inflammation, and 27 NASH), and 7 patients without NAFLD served as obese controls. Each group of NAFLD patients was compared with the obese controls, and 22 genes with more than twofold differences in expression levels were revealed. Proteomics analyses were performed for the same group comparisons and revealed twelve significantly different protein peaks. In conclusion, this genomic/proteomic analysis suggests differential expression of several genes and protein peaks in patients within and across the forms of NAFLD. These findings may help clarify the pathogenesis of NAFLD and identify potential targets for therapeutic intervention. (HEPATOLOGY 2005;42:665-674.)

Several differentially expressed genes in patients with NASH are related to lipid metabolism and extracellular matrix remodeling. Additionally, genes related to liver regeneration, apoptosis, and the detoxification process were differentially expressed. These findings may help clarify the molecular pathogenesis of NASH and identify potential targets for therapeutic intervention.

SummaryThe chorion is the acellular envelope surrounding mature eggs of teleostean fish. The macromolecular composition of the zebrafish (Danio rerio) egg chorion, organised as a three-layered structure, has been analysed. SDS-PAGE analysis, under reducing conditions, of isolated and purified chorions revealed a reproducible pattern of four major polypeptides (116, 97, 50 and 43kDa) and several minor bands. Lectin binding assays showed that both the 116 kDa and 50kDa proteins were recognised by concanavalin agglutinin (Con A), Galanthus nivalis agglutinin (GNA), Sambucus nigra bark agglutinin (SNA) and Ricinus communis agglutinin (RCA 120), suggesting that these polypeptides are N-linked glycoproteins. By contrast, neither the 97 kDa nor the 43 kDa polypeptides were stained by these lectins, indicating that these polypeptides are not glycosylated. Amino acid analysis also showed significant differences in the average content of some amino acids, for example serine and proline, when compared with previous reports.

In psychodynamic psychotherapy, verbal (structures and intents) and non-verbal (voice and interruptions) dimensions of communication intertwine conveying information and determining the mutual regulation between therapist and patient through conversational sequences. The communication components interplay is the foundation for building the therapeutic alliance, a relational dimension that predicts a psychotherapy outcome and change, influenced by patient-therapist exchanges from the initial stages of their encounter. Depressed patients present specific verbal and non-verbal communication and show difficulties in developing and maintaining the therapeutic alliance. Based on the reviewed literature, the main aim of this study was to analyze how the action of specific communicative modes, implemented by the therapist and depressed patients, affect the reciprocal construction of the early therapeutic alliance by each participant during the mutual regulation processes. We employed a mixed methods approach based on a systematic observation of communication and alliance ruptures and repairs within the audio recordings and verbatim transcripts of 20 psychotherapy sessions (6,232 speaking turns) with seven depressed patients. The observational design was nomothetic, follow-up, and multidimensional. The choice of methodology is justified because we developed a comprehensive procedure that integrates an ad hoc indirect observation system (the Communicative Modes Analysis System in Psychotherapy), analyzing verbal and non-verbal communication, and an observational tool with deductive categories (the Collaborative Interactions Scale-Revised), assessing the therapeutic alliance construction. Once we confirmed the intra-and inter-observer reliability for the ad hoc system and the inter-rater reliability for the tool with deductive (or theoretical) categories, we performed descriptive statistics (to describe quantitatively communicative modes and alliance Del Giacco et al. Communication Acts on Therapeutic Alliance ruptures and repairs), lag sequential analysis (to detect stable patterns in communication-alliance interactions), and polar coordinate analysis (to identify significant relationships between communicative modes and alliance ruptures and repairs). Results confirm that the therapist's verbal (asking and exploring) and non-verbal (elaborating and cooperatively interrupting) modes and the depressed patients' verbal (asserting and exploring) and non-verbal (expressing emotions and cooperatively interrupting) modes determine stable patterns and significant associations with collaborative behaviors connected to the reciprocal construction of alliance by each participant. All this may provide professionals with useful information to increase the psychotherapy effectiveness with depressed patients.

The developmental toxicity of nanostructured materials, as well as their impact on the biological barriers, represents a crucial aspect to be assessed in a nanosafety policy framework. Nanosized metal oxides have been demonstrated to affect Xenopus laevis embryonic development, with nZnO specifically targeting the digestive system. To study the mechanisms of the nZnO-induced intestinal lesions, we tested two different nominally sized ZnO nanoparticles (NPs) at effective concentrations. Advanced microscopy techniques and molecular marker analyses were applied in order to describe the NP-epithelial cell interactions and the mechanisms driving NP toxicity and translocation through the intestinal barrier. We attributed the toxicity to NP-induced cell oxidative damage, the small-sized NPs being the more effective. This outcome is sustained by a marked increase in anti-oxidant genes' expression and high lipid peroxidation level in the enterocytes, where disarrangement of the cytoskeleton and cell junctions' integrity were evidenced. These events led to diffuse necrotic changes in the intestinal barrier, and trans- and paracellular NP permeation through the mucosa. The uptake routes, leading NPs to cross the intestinal barrier and reach secondary target tissues, have been documented. nZnOs embryotoxicity was confirmed to be crucially mediated by the NPs' reactivity rather than their dissolved ions. The ZnO NPs' ability to overwhelm the intestinal barrier must be taken into high consideration for a future design of safer ZnO NPs.

The compass depressors (CDs) of the sea-urchin lantern are ligaments consisting mainly of discontinuous collagen fibrils associated with a small population of myocytes. They are mutable collagenous structures, which can change their mechanical properties rapidly and reversibly under nervous control. The aims of this investigation were to characterise the baseline (i.e. unmanipulated) static mechanical properties of the CDs of Paracentrotus lividus by means of creep tests and incremental force-extension tests, and to determine the effects on their mechanical behaviour of a range of agents. Under constant load the CDs exhibited a three-phase creep curve, the mean coefficient of viscosity being 561±365 MPa.s. The stress-strain curve showed toe, linear and yield regions; the mean strain at the toe-linear inflection was 0.86±0.61; the mean Young’s modulus was 18.62±10.30 MPa; and the mean tensile strength was 8.14±5.73 MPa. Hyaluronidase from Streptomyces hyalurolyticus had no effect on creep behaviour, whilst chondroitinase ABC prolonged primary creep but had no effect on secondary creep or on any force-extension parameters; it thus appears that neither hyaluronic acid nor sulphated glycosaminoglycans have an interfibrillar load transfer function in the CD. Acetylcholine, the muscarinic agonists arecoline and methacholine, and the nicotinic agonists nicotine and 1-[1-(3,4-dimethyl-phenyl)-ethyl]-piperazine produced an abrupt increase in CD viscosity; the CDs were not differentially sensitive to muscarinic or nicotinic agonists. CDs showed either no, or no consistent, response to adrenaline, L-glutamic acid, 5-hydroxytryptamine and γ-aminobutyric acid. Synthetic echinoid tensilin-like protein had a weak and inconsistent stiffening effect, indicating that, in contrast to holothurian tensilins, the echinoid molecule may not be involved in the regulation of collagenous tissue tensility. We compare in detail the mechanical behaviour of the CD with that of mammalian tendon and highlight its potential as a model system for investigating poorly understood aspects of the ontogeny and phylogeny of vertebrate collagenous tissues.

Background: Prox1, the vertebrate homolog of prospero in Drosophila melanogaster, is a divergent homeogene that regulates cell proliferation, fate determination and differentiation during vertebrate embryonic development.