Free-Standing DNA Origami Superlattice to Facilitate Cryo-EM Visualization of Membrane Vesicles

Technological breakthroughs in cryo-electron microscopy (cryo-EM) methods open new perspectives for highly detailed structural characterizations of extracellular vesicles (EVs) and synthetic liposome-protein assemblies. Structural characterizations of these vesicles in solution under a nearly native hydrated state are of great importance to decipher cell-to-cell communication and to improve EVs' application as markers in diagnosis and as drug carriers in disease therapy. However, difficulties in preparing holey carbon cryo-EM grids with low vesicle heterogeneities, at low concentration and with kinetic control of the chemical reactions or assembly processes, have limited cryo-EM use in the EV study. We report a straightforward membrane vesicle cryo-EM sample preparation method that assists in circumventing these limitations by using a free-standing DNA-affinity superlattice for covering holey carbon cryo-EM grids. Our approach uses DNA origami to self-assemble to a solution-stable and micrometer-sized ordered molecular template in which structure and functional properties can be rationally controlled. We engineered the template with cholesterol-binding sites to specifically trap membrane vesicles. The advantages of this DNA-cholesterol-affinity lattice (DCAL) include (1) local enrichment of artificial and biological vesicles at low concentration and (2) isolation of heterogeneous cell-derived membrane vesicles (exosomes) from a prepurified pellet of cell culture conditioned medium on the grid.

The structure of pathogenic huntingtin exon 1 defines the bases of its aggregation propensity

Huntington's disease is a neurodegenerative disorder caused by a CAG expansion in the first exon of the HTT gene, resulting in an extended polyglutamine (poly-Q) tract in huntingtin (httex1). The structural changes occurring to the poly-Q when increasing its length remain poorly understood due to its intrinsic flexibility and the strong compositional bias. The systematic application of site-specific isotopic labeling has enabled residue-specific NMR investigations of the poly-Q tract of pathogenic httex1 variants with 46 and 66 consecutive glutamines. Integrative data analysis reveals that the poly-Q tract adopts long α-helical conformations propagated and stabilized by glutamine side chain to backbone hydrogen bonds. We show that α-helical stability is a stronger signature in defining aggregation kinetics and the structure of the resulting fibrils than the number of glutamines. Our observations provide a structural perspective of the pathogenicity of expanded httex1 and pave the way to a deeper understanding of poly-Q-related diseases.

Mechanical Control of Cell Migration by the Metastasis Suppressor Tetraspanin CD82/KAI1

The plasma membrane is a key actor of cell migration. For instance, its tension controls persistent cell migration and cell surface caveolae integrity. Then, caveolae constituents such as caveolin-1 can initiate a mechanotransduction loop that involves actin- and focal adhesion-dependent control of the mechanosensor YAP to finely tune cell migration. Tetraspanin CD82 (also named KAI-1) is an integral membrane protein and a metastasis suppressor. Its expression is lost in many cancers including breast cancer. It is a strong inhibitor of cell migration by a little-known mechanism. We demonstrated here that CD82 controls persistent 2D migration of EGF-induced single cells, stress fibers and focal adhesion sizes and dynamics. Mechanistically, we found that CD82 regulates membrane tension, cell surface caveolae abundance and YAP nuclear translocation in a caveolin-1-dependent manner. Altogether, our data show that CD82 controls 2D cell migration using membrane-driven mechanics involving caveolin and the YAP pathway.

Nanoscale organization of tetraspanins during HIV-1 budding by correlative dSTORM/AFM

Membrane partition and remodeling play a key role in numerous cell mechanisms, especially in viral replication cycles where viruses subvert the plasma membrane to enter and escape from the host cell. Specifically assembly and release of HIV-1 particles require specific cellular components, which are recruited to the egress site by the viral protein Gag. We previously demonstrated that HIV-1 assembly alters both partitioning and dynamics of the tetraspanins CD9 and CD81, which are key players in many infectious processes, forming enriched areas where the virus buds. In this study we correlated super resolution microscopy mapping of tetraspanins with membrane topography delineated by atomic force microscopy (AFM) in Gag-expressing cells. We revealed that CD9 is specifically trapped within the nascent viral particles, especially at buds tips, suggesting that Gag mediates CD9 and CD81 depletion from the plasma membrane. In addition, we showed that CD9 is organized as small membrane assemblies of few tens of nanometers that can coalesce upon Gag expression.

SEIS: Insight's Seismic Experiment for Internal Structure of Mars

By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars' surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking's Mars seismic monitoring by a factor of ∼ 2500 at 1 Hz and ∼ 200 000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars' surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of M w ∼ 3 at 40 ∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution.

ELECTRONIC SUPPLEMENTARY MATERIAL

The online version of this article (10.1007/s11214-018-0574-6) contains supplementary material, which is available to authorized users.

A Developmental Social Neuroscience Model for Understanding Pathways to Substance Use Disorders During Adolescence

Adolescence is a transitional period of development characterized by critical changes in physical, neural, cognitive, affective, and social functions. Studies investigating the underlying mechanisms of substance use at levels of self-report, brain response, and behavioral data are generally consistent with suggestions from dual-process model that differential growth rates of frontally mediated control and striato-frontal reward processing are related to a heightened risk of substance use during adolescence. However, social theories highlight the important role of social context and environment in which adolescents grow up and suggest that growing up in an unfavorable environment and in particular exposure to adverse childhood experiences play a huge role in how this vulnerability is translated into actual risk. In this review, we provide a summary of recent theories that examine a number of key individual and social and environmental risk factors underlying risk for early initiation and escalation of substance misuse. We also present a model that expands the dual-process model to incorporate the role of negative self-concept and negative affect associated with growing up in an unfavorable environment and their interactions with cognitive control and inhibition to further explain vulnerability to early initiation and development of substance misuse in adolescents.

Can cannabis use be prevented by targeting personality risk in schools? Twenty-four-month outcome of the adventure trial on cannabis use: a cluster-randomized controlled trial

AIMS

To examine the effectiveness of a personality-targeted intervention program (Adventure trial) delivered by trained teachers to high-risk (HR) high-school students on reducing marijuana use and frequency of use.

DESIGN

A cluster-randomized controlled trial.

SETTING

Secondary schools in London, UK.

PARTICIPANTS

Twenty-one secondary schools were randomized to intervention (n = 12) or control (n = 9) conditions, encompassing a total of 1038 HR students in the ninth grade [mean (standard deviation) age = 13.7 (0.33) years].

INTERVENTIONS

Brief personality-targeted interventions to students with one of four HR profiles: anxiety sensitivity, hopelessness, impulsivity and sensation-seeking.

PRIMARY OUTCOME

marijuana use. Secondary outcome: frequency of use. Assessed using the Reckless Behaviour Questionnaire at intervals of 6 months for 2 years. Personality risk was measured with the Substance Use Risk Profile Scale.

FINDINGS

Logistic regression analysis revealed significant intervention effects on cannabis use rates at the 6-month follow-up in the intent-to-treat sample [odds ratio (OR) = 0.67, P = 0.05, 95% confidence interval (CI) = 0.45-1.0] and significant reductions in frequency of use at 12- and 18-month follow-up (β = -0.14, P ≤ 0.05, 95% CI = -0.6 to -0.01; β = -0.12, P ≤ 0.05, 95% CI = -0.54 to 0.0), but this was not supported in two-part latent growth models. Subgroup analyses (both logistic and two-part models) reveal that the sensation-seeking intervention delayed the onset of cannabis use among sensation seekers (OR = 0.25, β = -0.833, standard error = 0.342, P = 0.015).

CONCLUSIONS

Personality-targeted interventions can be delivered effectively by trained school staff to delay marijuana use onset among a subset of high-risk teenagers: sensation-seekers.

Nuclear pore complexes: guardians of the nuclear genome

Eukaryotic cell function depends on the physical separation of nucleoplasmic and cytoplasmic components by the nuclear envelope (NE). Molecular communication between the two compartments involves active, signal-mediated trafficking, a function that is exclusively performed by nuclear pore complexes (NPCs). The individual NPC components and the mechanisms that are involved in nuclear trafficking are well documented and have become textbook knowledge. However, in addition to their roles as nuclear gatekeepers, NPC components-nucleoporins-have been shown to have critical roles in chromatin organization and gene regulation. These findings have sparked new enthusiasm to study the roles of this multiprotein complex in nuclear organization and explore novel functions that in some cases appear to go beyond a role in transport. Here, we discuss our present view of NPC biogenesis, which is tightly linked to proper cell cycle progression and cell differentiation. In addition, we summarize new data suggesting that NPCs represent dynamic hubs for the integration of gene regulation and nuclear transport processes.

Woodland caribou calf recruitment in relation to calving/post-calving landscape composition

Since the 1990s, Newfoundland’s woodland caribou (Rangifer tarandus caribou) population has declined by an estimated 66%. Low calf recruitment has been associated to the decline, possibly triggered by increasing calf predation and/or decreasing resources. To investigate the role of landscape composition in this system, we studied the yearly (2005-2008) calving/post-calving range (CPCR) of 104 satellite-collared females belonging to six herds. We mapped nine disturbance factors (e.g. roads, logging, etc), as well as vegetation cover types (e.g. coniferous, deciduous forests, etc), and determined the total area they occupied within CPCRs yearly for each herd. Using an information theoretic approach, we assessed the model that best explained variation in recruitment using these components. Based on corrected Akaike Information Criterion, the model that best explained variation in calf recruitment included total disturbance and deciduous forest area, both showing the expected negative relationship with calf recruitment. Other landscape variables among the models with ΔAICc < 2 were mixed forest, also with a suggested negative relationship, and barrens and wetlands with a significant positive trend. This study highlights the need to minimize total disturbance footprint and account for resulting changes in forest composition within CPCRs during land use planning. Expanding forestry operations and road infrastructure in critical woodland caribou habitat across Canada may additionally contribute to habitat loss via fragmentation. This in turn, may lead to range recession beyond the initial local avoidance footprint. We see the possibility of using calf recruitment models based on landscape parameters, among others, to predict the impact of new industrial developments on calf recruitment.

Single bead affinity detection (SINBAD) for the analysis of protein-protein interactions

We present a miniaturized pull-down method for the detection of protein-protein interactions using standard affinity chromatography reagents. Binding events between different proteins, which are color-coded with quantum dots (QDs), are visualized on single affinity chromatography beads by fluorescence microscopy. The use of QDs for single molecule detection allows the simultaneous analysis of multiple protein-protein binding events and reduces the amount of time and material needed to perform a pull-down experiment.

Abnormalities of the gallbladder, clinical effects

The aim of this review of the literature was to present and discuss the anatomical and embryological basis of congenital abnormalities of the gallbladder, based on a case of volvulus. In the rare cases of ectopic gallbladder, diagnosis of a biliary disease could be difficult. In such cases surgery can also be dangerous, especially when it is associated with abnormalities of the intra-hepatic biliary and vascular tree. This study, based on the embryology of the extra hepatic bile duct, focused on the most frequent gallbladder abnormalities to keep them in mind.

A novel role for PA28gamma-proteasome in nuclear speckle organization and SR protein trafficking

In eukaryotic cells, proteasomes play an essential role in intracellular proteolysis and are involved in the control of most biological processes through regulated degradation of key proteins. Analysis of 20S proteasome localization in human cell lines, using ectopic expression of its CFP-tagged alpha7 subunit, revealed the presence in nuclear foci of a specific and proteolytically active complex made by association of the 20S proteasome with its PA28gamma regulator. Identification of these foci as the nuclear speckles (NS), which are dynamic subnuclear structures enriched in splicing factors (including the SR protein family), prompted us to analyze the role(s) of proteasome-PA28gamma complexes in the NS. Here, we show that knockdown of these complexes by small interfering RNAs directed against PA28gamma strongly impacts the organization of the NS. Further analysis of PA28gamma-depleted cells demonstrated an alteration of intranuclear trafficking of SR proteins. Thus, our data identify proteasome-PA28gamma complexes as a novel regulator of NS organization and function, acting most likely through selective proteolysis. These results constitute the first demonstration of a role of a specific proteasome complex in a defined subnuclear compartment and suggest that proteolysis plays important functions in the precise control of splicing factors trafficking within the nucleus.

Roles and potential therapeutic targets of the ubiquitin proteasome system in muscle wasting

Muscle wasting, characterized by the loss of protein mass in myofibers, is in most cases largely due to the activation of intracellular protein degradation by the ubiquitin proteasome system (UPS). During the last decade, mechanisms contributing to this activation have been unraveled and key mediators of this process identified. Even though much remains to be understood, the available information already suggests screens for new compounds inhibiting these mechanisms and highlights the potential for pharmaceutical drugs able to treat muscle wasting when it becomes deleterious. This review presents an overview of the main pathways contributing to UPS activation in muscle and describes the present state of efforts made to develop new strategies aimed at blocking or slowing muscle wasting.

Publication history: Republished from Current BioData's Targeted Proteins database (TPdb; ).

New approach to radiation burn treatment by dosimetry-guided surgery combined with autologous mesenchymal stem cell therapy

The therapeutic management of severe radiation burns remains a challenging issue. Conventional surgical treatment (excision and skin autograft or rotation flap) often fails to prevent unpredictable and uncontrolled extension of the radiation necrotic process. We report here an innovative therapeutic strategy applied to the victim of a radiation accident (December 15, 2005) with an iridium gammagraphy radioactive source (192Ir, 3.3 TBq). The approach combined numerical dosimetry-guided surgery with cellular therapy using mesenchymal stem cells. A very severe buttock radiation burn (2000 Gy at the center of the skin surface lesion) of a 27-year-old Chilean victim was widely excised (10 cm in diameter) using a physical and anatomical dose reconstruction in order to better define the limit of the surgical excision in apparently healthy tissues. A secondary extension of the radiation necrosis led to a new excision of fibronecrotic tissues associated with a local cellular therapy using autologous expanded mesenchymal stem cells as a source of trophic factors to promote tissue regeneration. Bone marrow-derived mesenchymal stem cells were expanded according to a clinical-grade technique using closed culture devices and serum-free medium enriched in human platelet lysate. The clinical evolution (radiation pain and healing progression) was favorable and no recurrence of radiation inflammatory waves was observed during the 11 month patient's follow-up. This novel multidisciplinary therapeutic approach combining physical techniques, surgical procedures and cellular therapy with adult stem cells may be of clinical relevance for improving the medical management of severe localized irradiations. It may open new prospects in the field of radiotherapy complications.

Protective role of selectin ligand inhibition in a large animal model of kidney ischemia-reperfusion injury

Experiments in rodents have demonstrated an important role for selectins in kidney ischemia-reperfusion injury (IRI). However, the relevance of this in larger mammals, as well as the impact on long-term structure and function is unknown. We tested the hypothesis that small molecule selectin ligand inhibition attenuates IRI, cellular inflammation, and long-term effects on renal interstitial fibrosis. We used a porcine model of kidney IRI and used Texas Biotechnology Corporation (TBC)-1269, a selectin ligand inhibitor. Renal function, tissue inflammation, and tubulointerstitial fibrosis development were evaluated up to 16 weeks. Both warm and cold ischemia models were studied for relevance to native and transplant kidney injury. Pigs treated with TBC-1269 during 45 min of warm ischemia (WI) showed significantly increased glomerular filtration rate compared to control animals. In pigs with severe IRI (WI for 60 min), TBC-1269 treatment during IRI significantly increased renal recovery. Cellular inflammation was strongly reduced, particularly influx of CD4 cells. Quantitative measurement of fibrosis by picrosirius red staining showed strong reduction in TBC-1269-treated groups. TBC-1269 also reduced cold IRI, inflammation, and fibrosis in kidneys preserved for 24 h at 4 degrees C and autotransplanted. The selectin ligand inhibitor TBC-1269 provides a novel and effective approach to attenuate IRI in both warm and cold ischemia in large mammals, in both short and long terms. Selectin ligand inhibition is an attractive strategy for evaluation in human kidney IRI.

Anatomical pitfalls in the technique for total extra peritoneal laparoscopic repair for inguinal hernias

PURPOSE

The totally extraperitoneal laparoscopic approach for the treatment of inguinal hernia is a well-recognized technique with proven efficacy, low failure rate, and reduced post-operative pain. This laparoscopic technique is reputed to be a more difficult procedure to learn and practice than a laparoscopic trans-abdomino-pre-peritoneal procedure: we hope this is because many surgeons don't well know extra-peritoneal anatomy of groin. So we proposed a "step by step" anatomical analysis, with pitfalls to avoid, of a totally extraperitoneal laparoscopic approach for treatment of inguinal hernia.

METHODS

Our experience with totally extraperitoneal laparoscopic inguinal hernia repair with regard to the morphology of the inguinal-femoral region concerns 23 cadaver dissection and more than 400 surgical procedures, now permits clarification of a surgical technique that has hitherto not been well known.

CONCLUSION

Photographic representations of surgical views are displayed, and detailed descriptions applicable to anatomical structures are presented.

Multiple phosphorylation events control mitotic degradation of the muscle transcription factor Myf5

Background

The two myogenic regulatory factors Myf5 and MyoD are basic helix-loop-helix muscle transcription factors undergoing differential cell cycle dependent proteolysis in proliferating myoblasts. This regulated degradation results in the striking expression of these two factors at distinct phases of the cell cycle, and suggests that their precise and alternated disappearance is an important feature of myoblasts, maybe connected to the maintenance of the proliferative status and/or commitment to the myogenic lineage of these cells. One way to understand the biological function(s) of the cyclic expression of these proteins is to specifically alter their degradation, and to analyze the effects of their stabilization on cells. To this aim, we undertook the biochemical analysis of the mechanisms governing Myf5 mitotic degradation, using heterologous systems.

Results

We show here that mitotic degradation of Myf5 is conserved in non-myogenic cells, and is thus strictly under the control of the cell cycle apparatus. Using Xenopus egg extracts as an in vitro system to dissect the main steps of Myf5 mitotic proteolysis, we show that (1) Myf5 stability is regulated by a complex interplay of phosphorylation/dephosphorylation, probably involving various kinases and phosphatases, (2) Myf5 is ubiquitylated in mitotic extracts, and this is a prerequisite to its degradation by the proteasome and (3) at least in the Xenopus system, the E3 responsible for its mitotic degradation is not the APC/C (the major E3 during mitosis).

Conclusion

Altogether, our data strongly suggest that the mitotic degradation of Myf5 by the ubiquitin-proteasome system is precisely controlled by multiple phosphorylation of the protein, and that the APC/C is not involved in this process.

Proteomic Study of Galectin-1 Expression in Human Mesenchymal Stem Cells

Bone marrow-derived mesenchymal stem cells (MSCs) are known to interact with hematopoietic stem cells (HSCs) and immune cells, and are of potential interest to be used as therapeutic agents for enhancing allogenic hematopoietic engraftment and preventing graft-versus-host disease (GVHD). Galectin 1 (Gal1) belongs to a family of structurally related molecules expressed in many vertebrate tissues that exert their functions both by binding to glycoconjugates, and by interaction with protein partners. In this work using a proteomic approach, we looked for the presence and the localization of Gal1 in short- and long-term culture of human (h) hMSC. We first determined, that Gal1 is one of the major proteins expressed in hMSC. We futher demonstrated that its expression is maintained when hMSC are expanded through a subculturing process up to five passages. Moreover, Gal1 is secreted and found at the cell surface of MSC, participating in extra cellular matrix (ECM)-cell interactions. Given the immunomodulatory properties of Gal1, its potential involvement in immunological functions of hMSC could be suggested.

Identification of an HLA-A*0201-restricted epitopic peptide from human dystrophin: application in duchenne muscular dystrophy gene therapy

Dystrophin-based gene therapy treatments aimed at correcting the Duchenne muscular dystrophy phenotype require stable expression of normal dystrophin (DYST) protein in myocytes without immune responses, which would compromise long-term expression. To predict cytotoxic T-cell-mediated responses elicited by transgenes, we used here H-2-negative HLA-A*0201 transgenic mice and identified human DYST epitopes, which elicit HLA-A*0201-restricted cytotoxic T cell activities. Among a series of eight peptides predicted from the human DYST sequence, not shared with the endogenous mouse DYST sequence, four of them were able to bind to HLA-A*0201 molecules and to induce cytotoxic T lymphocyte (CTL) responses. After human DYST DNA transfer in muscle of HLA-A*0201 mice, only the human DYST1281 epitope, located in the spectrin-like repeat 9 domain, induced strong CD8(+) CTL responses. Using the corresponding human DYST1281 peptide/HLA-A*0201 tetramer, we detected human DYST1281-specific CD8(+) T cells in peripheral lymphoid organs and blood of HLA-A*0201 mice injected with human DYST DNA. Our results demonstrate that muscle injection with human DYST DNA systematically triggers CTL responses against this HLA-A*0201-restricted human DYST1281 peptide, which is present in long human DYST isoforms. Identification of such immunodominant human DYST epitopes and use of peptide/HLA tetramers will allow the immunomonitoring of CTL responses in HLA-phenotyped Duchenne muscular dystrophy patients undergoing gene therapy. Finally, the knowledge of HLA-A*0201-restricted human DYST peptides will be of importance to test, in mouse models, new immunomodulatory interventions allowing long-term engraftment of human dystrophin.

Group therapy for pathological gamblers: a cognitive approach

This study evaluated the efficacy of a group cognitive treatment for pathological gambling. Gamblers, meeting DSM-IV criteria for pathological gambling, were randomly assigned to treatment (N=34) or wait-list control (N=24) conditions. Cognitive correction techniques were used first to target gamblers' erroneous perceptions about randomness, and then to address issues of relapse prevention. The dependent measures used were the DSM-IV criteria for pathological gambling, perceived self-efficacy, gamblers' perception of control, desire to gamble, and frequency of gambling. Post-treatment results indicated that 88% of the treated gamblers no longer met the DSM-IV criteria for pathological gambling compared to only 20% in the control group. Similar changes were observed on all outcome measures. Analysis of data from 6-, 12- and 24-month follow-ups revealed maintenance of therapeutic gains. Recommendations for group interventions are discussed, focusing on the cognitive correction of erroneous perceptions toward the notion of randomness.

Novel anti-inflammatory effects of the inhaled corticosteroid fluticasone propionate during lung myofibroblastic differentiation

Asthma is characterized by an irreversible subepithelial fibrosis with the appearance of myofibroblasts, which can be now considered important early participants in inflammatory responses as well as potential targets for anti-inflammatory drugs. In this study, we show that fluticasone propionate (FP), a powerful inhaled corticosteroid (ICS), displays novel anti-inflammatory effects on human lung fibroblasts during their myofibroblastic differentiation. Indeed, FP inhibits in lung myofibroblasts, at a very early stage of differentiation, the activation of Janus kinase/STAT pathways induced by IL-13 (tyrosine kinase 2, STAT1, STAT3, STAT6, mitogen-activated protein kinase). Contrarily, in mildly or fully differentiated myofibroblastic cultures, FP still displays a potential anti-inflammatory activity even if it only inhibits tyrosine kinase 2 phosphorylation. Moreover, FP inhibits constitutive and TGF-beta-induced expression of alpha-smooth muscle actin, the main marker of myofibroblastic differentiation, both in very early and in mild differentiated myofibroblasts. Finally, FP displays an additional powerful anti-inflammatory effect, decreasing nuclear translocation of NF-kappaB independent of the degree of myofibroblastic differentiation. These data 1) suggest that myofibroblasts are priority targets for ICS, which is able to revert them to a normal phenotype even if they appear to be already engaged in their differentiation, and 2) may help to explain why asthma is improved by an early ICS treatment, whereas advanced asthma is more resistant to these drugs.

Cognitive treatment of pathological gambling

This study evaluated the efficacy of a cognitive treatment package for pathological gambling. Sixty-six gamblers, meeting DSM-IV criteria for pathological gambling, were randomly assigned to treatment or wait-list control conditions. Cognitive correction techniques were used first to target gamblers' erroneous perceptions about randomness and then to address issues of relapse prevention. The dependent measures used were the South Oaks Gambling Screen, the number of DSM-IV criteria for pathological gambling met by participants, as well as gamblers' perception of control, frequency of gambling, perceived self-efficacy, and desire to gamble. Posttest results indicated highly significant changes in the treatment group on all outcome measures, and analysis of data from 6- and 12-month follow-ups revealed maintenance of therapeutic gains. Recommendations for clinical interventions are discussed, focusing on the cognitive correction of erroneous perceptions toward the notion of randomness.

Molecular analysis of apo(a) fragmentation in polygenic hypercholesterolemia: characterization of a new plasma fragment pattern

Hypercholesterolemia is frequently associated with elevated Lp(a) levels, an independent risk factor for coronary, cerebrovascular, and peripheral vascular disease. A portion of apolipoprotein(a) [apo(a)] circulates as a series of fragments derived from the N-terminal region of apo(a). The relationship of elevated lipoprotein(a) [Lp(a)] levels to those of circulating apo(a) fragments in polygenic hypercholesterolemia is indeterminate. Therefore, plasma Lp(a) and plasma and urinary apo(a) fragment levels were measured by ELISA in 82 patients with polygenic type IIa hypercholesterolemia (low density lipoprotein cholesterol >/=4.13 mmol/L and triglycerides <2.24 mmol/L) and in 90 normolipidemic subjects. Lp(a) levels were significantly elevated in patients compared with control subjects (0.35+/-0.4 and 0.24+/-0.31 mg/mL, respectively; median 0.13 and 0.11 mg/mL, respectively; P=0.039), although apo(a) isoform distribution did not differ. Patients displayed significantly higher plasma and urinary apo(a) fragment levels than did control subjects (respective values were as follows: 4.97+/-5.51 and 2.15+/-2.57 [median 2.85 and 1.17] microg/mL in plasma, P<0.0001; 75+/-86 and 40+/-57 [median 38 and 17] ng/mg urinary creatinine in urine, P<0.0001). The ratio of plasma apo(a) fragments to Lp(a) levels was also significantly higher in patients than in control subjects (1.93+/-1.5% and 1.75+/-2.36%, respectively; P<0.0001). We conclude that increased plasma Lp(a) levels in polygenic hypercholesterolemia are associated with elevated circulating levels of apo(a) fragments but that this increase is not due to decreased renal clearance of apo(a) fragments. Furthermore, we identified a new pattern of apo(a) fragmentation characterized by the predominance of a fragment band whose size was related to that of the parent apo(a) isoform and that was superimposed on the series of fragments described previously by Mooser et al (J Clin Invest. 1996; 98:2414-2424). This new pattern was associated with small apo(a) isoforms and did not discriminate between hypercholesterolemic and normal subjects. However, this new apo(a) fragment pattern may constitute a novel marker for cardiovascular risk.

Unusual interleukin-4 and -13 signaling in human normal and tumor lung fibroblasts

IL-4 and IL-13 act on human lung fibroblasts through specific receptors differing in their composition. Indeed, the gammac chain is constitutively expressed in tumor lung myofibroblast but not in normal cells. Here, we have analysed the signal transduction induced by IL-4 and IL-13 in both cell types, in order to better understand the molecular mechanisms underlying tumor stromal development. The IL-4Ralpha chain is constitutively phosphorylated and pre-associated with the JAK1 protein in both cell types. In normal cells, we detected the activation of the classic IRS-2 or JAK1/STAT6 pathways, the phosphorylation of JAK2, while Tyk2 was constitutively phosphorylated and not modified by both cytokines. In addition to these pathways, in lung tumor myofibroblasts, IL-4 and IL-13 induced the phosphorylation of JAK3 and increased the phosphorylation of Tyk2. Interestingly, in both cell types IL-4 and IL-13 triggered an unusual pattern of STAT1 and STAT3 activation. These events probably correspond to a tissue-specific signaling important for the immunoregulatory functions of airways fibroblasts. Indeed, the inflammatory-like pattern of STATs signaling triggered by IL-4 and IL-13 in these cells may favor the homing of inflammatory and/or metastatic cells. In lung myofibroblasts, these properties could be modified through the different pattern of JAK activation.

An event-related potential analysis of extraversion and individual differences in cognitive processing speed and response execution

Individual differences in cognitive processing speed and response execution were examined in relation to extraversion. Event-related potentials (ERPs) were recorded concurrently with reaction time and movement time (MT) measures as participants (N = 67) performed simple reaction time and stimulus-response compatibility tasks. Slower processing speed for extraverts, as indicated by longer latency of a late positive ERP wave, P3, was only evident in conditions in which stimulus information was in conflict with response selection demands. As previously reported, the salient effect in all conditions of both tasks was faster MT for extraverts, an effect that is indicative of differences in fundamental motor processes. On the simple reaction time task, amplitudes of the N1 component, an early negative ERP wave, were smaller for extraverts than for introverts in response to auditory tones, an effect that affirms the enhanced sensory reactivity of introverts to punctate physical stimuli.

[Clinical study of dermatoses as psychosomatic phenomena]

The aim of this presentation is to introduce some aspects of the global problematics of our Phd research in psychopathology. This thesis shows that all the studies on the relations between body and mind agree to say that there are organic symptoms with a psychical etiology. Some of these symptoms can be called, under certain conditions, "psychosomatic phenomena". We are showing that, in case of a disease, a skin disease in the framework of this research, two questions must be raised: does the disease have a function in the psychical structure? which one? In this view, a case study enables us to examine the link between somatic pathology and psychical features of the subject who is affected by it, and that can be done only by examining the event which brought on the disease.

The scripting of activities of daily living in normal aging: anticipation and shifting deficits with preservation of sequencing

The purpose of this study was to elaborate upon Shallice's frontal lobe model by evaluating 20 elderly normal and 20 young adult controls, all women, with cognitive tests, a paper-pencil script generation task and a kitchenette meal preparation task. The elderly were significantly weaker on standardized tests of executive functions and on the paper-pencil script generation task. An anticipation and a sequencing impairment clearly emerged. Though anticipation and shifting were compromised in the kitchenette script task, sequencing was however preserved. This supports Shallice's notion according to which scripting is hierarchically organized with top level components being more frontal lobe dependent (supervisory attentional system or SAS) and the lower level components more tributary to subcortical circuits involving procedural learning (contention scheduling or CS).

Coumarinic derivatives as mechanism-based inhibitors of alpha-chymotrypsin and human leukocyte elastase

Novel coumarinic derivatives were synthesized and tested for their inhibitory potency toward alpha-CT and HLE. Cycloalkyl esters and amides were found to be essentially inactive on both enzymes. On the opposite, aromatic esters strongly inactivated alpha-CT whereas HLE was less efficiently inhibited with dichlorophenyl ester derivatives (kinact/K(I) = 4000 M(-1) s(-1) for 36). Representative examples of amide, ester, thioester and ketone derivatives were prepared in order to evaluate the influence of the link between the coumarinic ring and the phenyl side chain. The irreversible inactivation of alpha-CT by 6-chloromethyl derivatives should be due to alkylation of a histidine residue as suggested by the amino acid analysis of the modified chymotrypsin. Conversely the inhibition of HLE was transient. Intrinsic reactivity of coumarins has been calculated using a model of a nucleophilic reaction between the ligand and the couple methanol-water. From this calculation, it appears that differences in the inhibitory potency expressed by these molecules cannot only be explained by differences in the reactivity of the lactonic carbonyl group toward the nucleophilic attack.

An event-related potential analysis of extraversion and individual differences in cognitive processing speed and response execution

Individual differences in cognitive processing speed and response execution were examined in relation to extraversion. Event-related potentials (ERPs) were recorded concurrently with reaction time and movement time (MT) measures as participants (N = 67) performed simple reaction time and stimulus-response compatibility tasks. Slower processing speed for extraverts, as indicated by longer latency of a late positive ERP wave, P3, was only evident in conditions in which stimulus information was in conflict with response selection demands. As previously reported, the salient effect in all conditions of both tasks was faster MT for extraverts, an effect that is indicative of differences in fundamental motor processes. On the simple reaction time task, amplitudes of the N1 component, an early negative ERP wave, were smaller for extraverts than for introverts in response to auditory tones, an effect that affirms the enhanced sensory reactivity of introverts to punctate physical stimuli.

Chemokines and CD40 expression in human fibroblasts

Chemokines are cytokines specialized for recruiting leukocytes in inflammatory responses. Recent data indicate that besides macrophages and leukocytes fibroblasts may also be a source of these important immune molecules. We assayed chemokine expression (mRNA/ protein) in cultured fibroblasts isolated from a variety of human tissues and different pathologic states: normal bone marrow vs. myelometaplastic spleen, normal lung vs. metastasis stroma, and normal breast vs. radiation fibrosis and tumor stroma. In all fibroblasts, transcripts for chemokines IL-8, stromal cell-derived factor-1, monocyte chemotactic protein (MCP)-1 and eotaxin were detected. Although the production of IL-8 was abundant in most of the fibroblasts studied, fibroblasts from lung and pathologic breast tissue produced significantly less. Conversely, eotaxin production was low in most fibroblasts except in those isolated from myelometaplastic tissue where it was highly produced. Moreover, chemokines MCP-4, RANTES and macrophage inflammatory protein-1alpha were found to be expressed only in fibroblasts from select tissues. When the expression of CD40, an activating surface molecule for immune cells, was investigated, we found that most of the fibroblasts expressed this antigen. Overall these results indicate that cultured human fibroblasts from various tissues and pathologic settings produce a distinct panel of chemokines and express CD 40, suggesting a possible fundamental role of fibroblasts in immune responses and disease processes.

6-Substituted 2-oxo-2H-1-benzopyran-3-carboxylic acid as a core structure for specific inhibitors of human leukocyte elastase

Pyridyl esters of 6-substituted 2-oxo-2H-1-benzopyran-3-carboxylic acid were designed as mechanism-based inhibitors of human leukocyte elastase. Compounds of series 4 specifically inhibited this enzyme. Several of the tested compounds (series 2 and 3) acted as powerful time-dependent inhibitors of both human leukocyte elastase and alpha-chymotrypsin; some compounds of these series inhibited thrombin. Trypsin was not inhibited. A transient inactivation was observed for human leukocyte elastase (k(i)/K(I) = 107 000 M(-1). s(-1) for 4c) and thrombin (k(i)/K(I) = 7 200 M(-1).s(-1) for 3b) as demonstrated by spontaneous or hydroxylamine-accelerated reactivation, irrespective of the nature of the substituent at the 6-position. Conversely, alpha-chymotrypsin was irreversibly inhibited by 6-chloromethyl derivatives (k(i)/K(I) = 107 400 M(-1). s(-1) for 3b). The presence of a latent alkylating function at the 6-position (chloromethyl group) was required for leading to this inactivation. In the absence of such an alkylating function (series 4), human leukocyte elastase was specifically inhibited suggesting that this new series of human leukocyte elastase inhibitors may be of potential therapeutic interest in degradative and degenerative processes involving this enzyme.