Securin and separase modulate membrane traffic by affecting endosomal acidification.

Securin and separase play a key role in sister chromatid separation during anaphase. However, a growing body of evidence suggests that in addition to regulating chromosome segregation, securin and separase display functions implicated in membrane traffic in Caenorhabditis elegans and Drosophila. Here we show that in mammalian cells both securin and separase associate with membranes and that depletion of either protein causes robust swelling of the trans-Golgi network (TGN) along with the appearance of large endocytic vesicles in the perinuclear region. These changes are accompanied by diminished constitutive protein secretion as well as impaired receptor recycling and degradation. Unexpectedly, cells depleted of securin or separase display defective acidification of early endosomes and increased membrane recruitment of vacuolar (V-) ATPase complexes, mimicking the effect of the specific V-ATPase inhibitor Bafilomycin A1. Taken together, our findings identify a new functional role of securin and separase in the modulation of membrane traffic and protein secretion that implicates regulation of V-ATPase assembly and function.

What process research tells us about brief intervention efficacy.

ISSUE: This article explores mechanisms of the efficacy of brief intervention (BI). APPROACH: We conducted a BI trial at the emergency department of the Lausanne University Hospital, of whom 987 at-risk drinkers were randomised into BI and control groups. The overall results demonstrated a general decrease in alcohol use with no differences across groups. The intention to change was explored among 367 patients who completed BI. Analyses of 97 consecutive tape-recorded sessions explored patient and counsellor talks during BI, and their relationship to alcohol use outcome. KEY FINDINGS: Evaluation of the articulation between counsellor behaviours and patient language revealed a robust relationship between counsellor motivational interviewing (MI) skills and patient change talk during the intervention. Further exploration suggested that communication characteristics of patients during BI predicted changes in alcohol consumption 12 months later. Moreover, despite systematic training, important differences in counsellor performance were highlighted. Counsellors who had superior MI skills achieved better outcomes overall, and maintained efficacy across all levels of patient ability to change, whereas counsellors with inferior MI skills were effective mostly with patients who had higher levels of ability to change. Finally, the descriptions of change talk trajectories within BI and their association with drinking 12 months later showed that final states differed from initial states, suggesting an impact resulting from the progression of change talk during the course of the intervention. IMPLICATION: These findings suggest that BI should focus on the general MI attitude of counsellors who are capable of eliciting beneficial change talk from patients. [Daeppen J-B, Bertholet N, Gaume J. What process research tells us about brief intervention efficacy.

Finite field treatment of vibrational polarizabilities and hyperpolarizabilities: on the role of the Eckart conditions, their implementation, and their use in characterizing key vibrations

In the finite field (FF) treatment of vibrational polarizabilities and hyperpolarizabilities, the field-free Eckart conditions must be enforced in order to prevent molecular reorientation during geometry optimization. These conditions are implemented for the first time. Our procedure facilities identification of field-induced internal coordinates that make the major contribution to the vibrational properties. Using only two of these coordinates, quantitative accuracy for nuclear relaxation polarizabilities and hyperpolarizabilities is achieved in π-conjugated systems. From these two coordinates a single most efficient natural conjugation coordinate (NCC) can be extracted. The limitations of this one coordinate approach are discussed. It is shown that the Eckart conditions can lead to an isotope effect that is comparable to the isotope effect on zero-point vibrational averaging, but with a different mass-dependence

Intrauterine exposure to carbamazepine and specific congenital malformations: systematic review and case-control study.

OBJECTIVE: To identify specific major congenital malformations associated with use of carbamazepine in the first trimester of pregnancy. DESIGN: A review of all published cohort studies to identify key indications and a population based case-control study to test these indications. SETTING: Review of PubMed, Web of Science, and Embase for papers about carbamazepine exposure in the first trimester of pregnancy and specific malformations, and the EUROCAT Antiepileptic Study Database, including data from 19 European population based congenital anomaly registries, 1995-2005. PARTICIPANTS: The literature review covered eight cohort studies of 2680 pregnancies with carbamazepine monotherapy exposure, and the EUROCAT dataset included 98 075 registrations of malformations covering over 3.8 million births. MAIN OUTCOME MEASURES: Overall prevalence for a major congenital malformation after exposure to carbamazepine monotherapy in the first trimester. Odds ratios for malformations with exposure to carbamazepine among cases (five types of malformation identified in the literature review) compared with two groups of controls: other non-chromosomal registrations of malformations and chromosomal syndromes. RESULTS: The literature review yielded an overall prevalence for a major congenital malformation of 3.3% (95% confidence interval 2.7 to 4.2) after exposure to carbamazepine monotherapy in the first trimester. In 131 registrations of malformations, the fetus had been exposed to carbamazepine monotherapy. Spina bifida was the only specific major congenital malformation significantly associated with exposure to carbamazepine monotherapy (odds ratio 2.6 (95% confidence interval 1.2 to 5.3) compared with no antiepileptic drug), but the risk was smaller for carbamazepine than for valproic acid (0.2, 0.1 to 0.6). There was no evidence for an association with total anomalous pulmonary venous return (no cases with carbamazepine exposure), cleft lip (with or without palate) (0.2, 0.0 to 1.3), diaphragmatic hernia (0.9, 0.1 to 6.6), or hypospadias (0.7, 0.3 to 1.6) compared with no exposure to antiepileptic drugs. Further exploratory analysis suggested a higher risk of single ventricle and atrioventricular septal defect. CONCLUSION: Carbamazepine teratogenicity is relatively specific to spina bifida, though the risk is less than with valproic acid. Despite the large dataset, there was not enough power to detect moderate risks for some rare major congenital malformations.

Relations among several nuclear and electronic density functional reactivity indexes

A set of connections among several nuclear and electronic indexes of reactivity in the framework of the conceptual Density Functional Theory by using an expansion ofthe energy functional in terms of the total number of electrons and the normal coordinates within a canonical ensemble was derived. The relations obtained provided explicit links between important quantities related to the chemical reactivity of a system. This paper particularly demonstrates that the derivative of the electronic energy with respect to the external potential of a system in its equilibrium geometry was equal to the negative of the nuclear repulsion derivative with respect to the external potential

Electronic couplings and on-site energies for hole transfer in DNA: systematic quantum mechanical/molecular dynamic study

The electron hole transfer (HT) properties of DNA are substantially affected by thermal fluctuations of the π stack structure. Depending on the mutual position of neighboring nucleobases, electronic coupling V may change by several orders of magnitude. In the present paper, we report the results of systematic QM/molecular dynamic (MD) calculations of the electronic couplings and on-site energies for the hole transfer. Based on 15 ns MD trajectories for several DNA oligomers, we calculate the average coupling squares 〈 V2 〉 and the energies of basepair triplets X G+ Y and X A+ Y, where X, Y=G, A, T, and C. For each of the 32 systems, 15 000 conformations separated by 1 ps are considered. The three-state generalized Mulliken-Hush method is used to derive electronic couplings for HT between neighboring basepairs. The adiabatic energies and dipole moment matrix elements are computed within the INDO/S method. We compare the rms values of V with the couplings estimated for the idealized B -DNA structure and show that in several important cases the couplings calculated for the idealized B -DNA structure are considerably underestimated. The rms values for intrastrand couplings G-G, A-A, G-A, and A-G are found to be similar, ∼0.07 eV, while the interstrand couplings are quite different. The energies of hole states G+ and A+ in the stack depend on the nature of the neighboring pairs. The X G+ Y are by 0.5 eV more stable than X A+ Y. The thermal fluctuations of the DNA structure facilitate the HT process from guanine to adenine. The tabulated couplings and on-site energies can be used as reference parameters in theoretical and computational studies of HT processes in DNA

Estimation of electronic coupling in π -stacked donor-bridge-acceptor systems: correction of the two-state model

Comparison of donor-acceptor electronic couplings calculated within two-state and three-state models suggests that the two-state treatment can provide unreliable estimates of Vda because of neglecting the multistate effects. We show that in most cases accurate values of the electronic coupling in a π stack, where donor and acceptor are separated by a bridging unit, can be obtained as Ṽ da = (E2 - E1) μ12 Rda + (2 E3 - E1 - E2) 2 μ13 μ23 Rda2, where E1, E2, and E3 are adiabatic energies of the ground, charge-transfer, and bridge states, respectively, μij is the transition dipole moments between the states i and j, and Rda is the distance between the planes of donor and acceptor. In this expression based on the generalized Mulliken-Hush approach, the first term corresponds to the coupling derived within a two-state model, whereas the second term is the superexchange correction accounting for the bridge effect. The formula is extended to bridges consisting of several subunits. The influence of the donor-acceptor energy mismatch on the excess charge distribution, adiabatic dipole and transition moments, and electronic couplings is examined. A diagnostic is developed to determine whether the two-state approach can be applied. Based on numerical results, we showed that the superexchange correction considerably improves estimates of the donor-acceptor coupling derived within a two-state approach. In most cases when the two-state scheme fails, the formula gives reliable results which are in good agreement (within 5%) with the data of the three-state generalized Mulliken-Hush model

Electronic and vibrational contributions to first hyperpolarizability of donor-acceptor-substituted azobenzene

In this study we report on the electronic and vibrational (hyper)polarizabilities of donor–acceptorsubstituted azobenzene. It is observed that both electronic and vibrational contributions to the electricdipole first hyperpolarizability of investigated photoactive molecule substantially depend on the conformation. The contributions to the nuclear relaxation first hyperpolarizability are found to be quite important in the case of two considered isomers (cis and trans). Although the double-harmonic term is found to be the largest in terms of magnitude, it is shown that the total value of the nuclear relaxation contribution to vibrational first hyperpolarizability is a result of subtle interplay of higher-order contributions. As a part of the study, we also assess the performance of long-range-corrected densityfunctional theory in determining vibrational contributions to electric dipole (hyper)polarizabilities. In most cases, the applied long-range-corrected exchange correlation potentials amend the drawbacks of their conventional counterparts

Proximal tibia volumetric bone mineral density is correlated to the magnitude of local acceleration in male long distance runners.

Introduction: The beneficial effect of physical exercise on bone mineral density (BMD) is at least partly explained by the forces exerted directly on the bones. Male runners present generally higher BMD than sedentary individuals. We postulated that the proximal tibia BMD is related to the running distance as well as to the magnitude of the shocks (while running) in male runners. Methods: A prospective study (three yearly measurements) included 81 healthy male subjects: 16 sedentary lean subjects and three groups of runners (5-30 km/week, n=19; 30-50 km/week, n=29; 50-100 km/week, n=17). Several measurements were performed at the proximal tibia level: volumetric BMD (vBMD), cortical index (CI) i.e. an index of cortical bone thickness and peak accelerations (an index of shocks during heel strike) while running (measured by a 3-D accelerometer). A general linear model assessed the prediction of vBMD or CI by a) simple effects (running distance, peak accelerations, time) and b) interactions (for instance if vBMD prediction by peak acceleration depends on running distance). Results: CI and vBMD a) increase with running distance to reach a plateau over 30 km/wk, b) are positively associated with peak accelerations over 30 km/week. Discussion: Running may be associated with high peak accelerations in order to have beneficial effects on BMD. More important strains are needed to be associated with the same increase in BMD during running sessions of short duration than those of long duration. Conclusion: CI and vBMD are associated with the magnitude of the shocks during heel strike in runners. Key words: Bone mineral density, strains, physical exercise, running distance.

Opioid maintenance therapy in Switzerland: an overview of the Swiss IMPROVE study.

BACKGROUND/AIMS: Switzerland's drug policy model has always been unique and progressive, but there is a need to reassess this system in a rapidly changing world. The IMPROVE study was conducted to gain understanding of the attitudes and beliefs towards opioid maintenance therapy (OMT) in Switzerland with regards to quality and access to treatment. To obtain a "real-world" view on OMT, the study approached its goals from two different angles: from the perspectives of the OMT patients and of the physicians who treat patients with maintenance therapy. The IMPROVE study collected a large body of data on OMT in Switzerland. This paper presents a small subset of the dataset, focusing on the research design and methodology, the profile of the participants and the responses to several key questions addressed by the questionnaires. METHODS: IMPROVE was an observational, questionnaire-based cross-sectional study on OMT conducted in Switzerland. Respondents consisted of OMT patients and treating physicians from various regions of the country. Data were collected using questionnaires in German and French. Physicians were interviewed by phone with a computer-based questionnaire. Patients self-completed a paper-based questionnaire at the physicians' offices or OMT treatment centres. RESULTS: A total of 200 physicians and 207 patients participated in the study. Liquid methadone and methadone tablets or capsules were the medications most commonly prescribed by physicians (60% and 20% of patient load, respectively) whereas buprenorphine use was less frequent. Patients (88%) and physicians (83%) were generally satisfied with the OMT currently offered. The current political framework and lack of training or information were cited as determining factors that deter physicians from engaging in OMT. About 31% of OMT physicians interviewed were ≥60 years old, indicating an ageing population. Diversion and misuse were considered a significant problem in Switzerland by 45% of the physicians. CONCLUSION: The subset of IMPROVE data presented gives a present-day, real-life overview of the OMT landscape in Switzerland. It represents a valuable resource for policy makers, key opinion leaders and drug addiction researchers and will be a useful basis for improving the current Swiss OMT model.

Genetics for clinicians: from candidate genes to whole genome scans (technological advances).

Human genetics has progressed at an unprecedented pace during the past 10 years. DNA microarrays currently allow screening of the entire human genome with high level of coverage and we are now entering the era of high-throughput sequencing. These remarkable technical advances are influencing the way medical research is conducted and have boosted our understanding of the structure of the human genome as well as of disease biology. In this context, it is crucial for clinicians to understand the main concepts and limitations of modern genetics. This review will describe key concepts in genetics, including the different types of genetic markers in the human genome, review current methods to detect DNA variation, describe major online public databases in genetics, explain key concepts in statistical genetics and finally present commonly used study designs in clinical and epidemiological research. This review will therefore concentrate on human genetic variation analysis.

Microscòpia d'alta resolució aplicada a anàlisis traceològiques, tafonòmiques i zooarqueològiques

El projecte Microscòpia d'alta resolució aplicada a anàlisis traceològiques, tafonòmiques y zooarqueològiques ha permès donar continuïtat i ampliar la xarxa científica posada en marxa gràcies a dos projectes PBR anteriors entre l’IPHES i quatre centres anglesos: l’Institute of Archaeology del University College of London, el Dept of Prehistory and Europe del British Museum, el Dept of Palaeontology del Natural History Museum, i el Lithic Microwear Research Laboratory de la University of Bradford. El tema tractat ha estat l’avaluació de la resolució i de la possible complementarietat de diferents tècniques avançades de microscòpia per a l’anàlisi de les superfícies d’ossos i eines de pedra prehistòriques: microscòpia òptica, electrònica (SEM i ESEM), microscòpia làser confocal (LSCM) i el sistema Alicona 3D Infinite Imaging. Les diverses accions de mobilitat entre Catalunya i el Regne Unit realitzades han permès satisfactòriament posar en comú els procediments emprats pels diferents especialistes de cada centre. Les proves realitzades sobre materials de jaciments arqueològics clau tant britànics com de l’estat espanyol han permès avaluar els avantatges i limitacions que cada tècnica presentava segons la mostra estudiada (eines de pedra, ossos, dents...) i segons els requeriments específics de l’estudi plantejat. En termes generals, s’ha posat en evidència que les diferents tècniques explorades són força complementàries. És a dir, la gran capacitat d’augments i de resolució d’imatge dels microscopis electrònics es complementa amb unes meravelloses prestacions quant anàlisi de textures, de perfils i de reconstrucció 3D dels altres aparells. La principal conclusió que podem extreure, doncs, és que l’estudi d’aquest tipus d’objectes arqueològics requereix de l’ús combinat de diferents aparells de microscòpia. Tant els treballs realitzats com els contactes entre especialistes establerts al llarg del projecte s’han plasmat ja en treballs concrets, alguns d’ells ja publicats o en fase final de publicació.

Molecular chaperones and associated cellular clearance mechanisms against toxic protein conformers in Parkinson's disease.

Parkinson's disease (PD) is a slowly progressive neurodegenerative disorder marked by the loss of dopaminergic neurons (in particular in the substantia nigra) causing severe impairment of movement coordination and locomotion, associated with the accumulation of aggregated α-synuclein (α-Syn) into proteinaceous inclusions named Lewy bodies. Various early forms of misfolded α-Syn oligomers are cytotoxic. Their formation is favored by mutations and external factors, such as heavy metals, pesticides, trauma-related oxidative stress and heat shock. Here, we discuss the role of several complementing cellular defense mechanisms that may counteract PD pathogenesis, especially in youth, and whose effectiveness decreases with age. Particular emphasis is given to the 'holdase' and 'unfoldase' molecular chaperones that provide cells with potent means to neutralize and scavenge toxic protein conformers. Because chaperones can specifically recognize misfolded proteins, they are key specificity factors for other cellular defenses, such as proteolysis by the proteasome and autophagy. The efficiency of the cellular defenses decreases in stressed or aging neurons, leading to neuroinflammation, apoptosis and tissue loss. Thus, drugs that can upregulate the molecular chaperones, the ubiquitin-proteasome system and autophagy in brain tissues are promising avenues for therapies against PD and other mutation-, stress- or age-dependent protein-misfolding diseases.

Sequencing and characterizing the genome of Estrella lausannensis as an undergraduate project: training students and biological insights.

With the widespread availability of high-throughput sequencing technologies, sequencing projects have become pervasive in the molecular life sciences. The huge bulk of data generated daily must be analyzed further by biologists with skills in bioinformatics and by "embedded bioinformaticians," i.e., bioinformaticians integrated in wet lab research groups. Thus, students interested in molecular life sciences must be trained in the main steps of genomics: sequencing, assembly, annotation and analysis. To reach that goal, a practical course has been set up for master students at the University of Lausanne: the "Sequence a genome" class. At the beginning of the academic year, a few bacterial species whose genome is unknown are provided to the students, who sequence and assemble the genome(s) and perform manual annotation. Here, we report the progress of the first class from September 2010 to June 2011 and the results obtained by seven master students who specifically assembled and annotated the genome of Estrella lausannensis, an obligate intracellular bacterium related to Chlamydia. The draft genome of Estrella is composed of 29 scaffolds encompassing 2,819,825 bp that encode for 2233 putative proteins. Estrella also possesses a 9136 bp plasmid that encodes for 14 genes, among which we found an integrase and a toxin/antitoxin module. Like all other members of the Chlamydiales order, Estrella possesses a highly conserved type III secretion system, considered as a key virulence factor. The annotation of the Estrella genome also allowed the characterization of the metabolic abilities of this strictly intracellular bacterium. Altogether, the students provided the scientific community with the Estrella genome sequence and a preliminary understanding of the biology of this recently-discovered bacterial genus, while learning to use cutting-edge technologies for sequencing and to perform bioinformatics analyses.

Entrained macrocryst minerals as a key to the source region of olivine nephelinites: Humberg, Kaiserstuhl, Germany

Olivine nephelinites commonly contain macrocrysts of olivine and clinopyroxene. Some of these macrocrysts might represent fragments of the source region of the host magma transported to the Earth surface. If this hypothesis is correct these fragments can be used to characterize the composition of the source region and to put constraints on the magma generation process. In this study, we investigate the origin of macrocrysts and mineral aggregates from an olivine nephelinite from the Kaiserstuhl, Germany. We focus on clinopyroxenes (Cpx), which can be divided into three groups. Cpx I is relict Cpx from aggregates with deformed olivine that is depleted in Ca and characterized by strong light rare earth element (LREE) fractionation, low Ti/Eu and negative high field strength element (HFSE) anomalies. Its geochemical signature is consistent with formation by carbonatite metasomatism and with equilibration in the Presence of orthopyroxene. Cpx II is Ca-rich Cpx, forming both aggregates with deformed olivine and individual macrocrysts. The LREE, as for Cpx I, are strongly fractionated. Convex REE patterns may be present. The depletion in HFSE is less pronounced. Cpx III is oscillatory zoned Cpx phenociysis showing enrichment in Ca, convex REE patterns and no HFSE anomalies. The transition in the trace element abundances between the Cpx of the three groups is gradual. However, Cpx I and H did not crystallize from the host magma, as demonstrated by the presence of kink-bands and undulose extinction in the associated olivine and by the composition of alkali aluminosilicate glass inclusions in Cpx H. Based on the Cpx relationships, we interpret the studied suite of macrocrysts and mineral aggregates as a mixture of disintegrated fragments of the source region of the host olivine nephelinite. The process of melt generation was multi-stage. A primary carbonatite melt ascending from deeper levels in the mantle, probably from the dolomite-garnet peridotite stability field, reacted with mantle peridotite along the solidus ledge in the system lherzolite-CO2 (< 20-22 kbar) and started to crystallize carbonate minerals. Because of its low solidus temperature, the resulting carbonate-wehrlite assemblage melted incongruently with the formation of additional clinopyroxene. The carbonatite melt evolved during crystallization of carbonate minerals and concomitant incongruent melting of the carbonate-wehrlite, accompanied by the segregation of incipient alkali aluminosilicate melts. As a consequence of fast reaction rates in the presence of a carbonatite melt, this process probably took place under disequilibrium conditions. Further melting of the assemblage wehrlite + alkali aluminosilicate melt led to the generation of the olivine nephelinite magma. It entrained fragments of the wehrlite and brought them to the surface.