Primer consenso cubano sobre el uso de terapia convencional y biológica en pacientes con artritis reumatoide / First Cuban consensus on the use of conventional and biological therapy in patients with rheumatoid arthritis

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Introduction: The development of recommendations for the treatment of rheumatoid arthritis (RA) in the Cuban context may be one of the ways to achieve better control of this disease. Objective: To reach a consensus and update relevant aspects of conventional and biological RA modifier therapy in Cuba. Methods: 18 specialists from 8 Cuban provinces, experts in RA care, were summoned, according to the years of dedication to the specialty, the conferences on this topic and their publications. The first meeting took place in March 2016 in the provincial hospital of Villa Clara, Cuba, with the participation of all the experts. A review of the literature on conventional and biological therapy previously collected by the participants was developed, and two teams were formed: the first would address everything related to conventional therapy in RA (HRCT) and the other, biological therapy in RA (TBAR). Three questionnaires related to the use of corticosteroids, HRCT and TBAR, were prepared, answered by the participants via email. In a second meeting, held in October 2016 in Havana, the analysis of all the responses provided was carried out. Questions with a response of 90% or more votes were considered as recommendations. Results: The questionnaires were answered by 95% of the participants. 9 recommendations and 1 algorithm were established. The recommendations are as follows: methotrexate is the drug of choice in the treatment of RA after diagnosis; The administration of another conventional drug (DMARDc) (azathioprine, salazosulfapyridine, antimalarials and leflunomide) is recommended in patients with a diagnosis of active RA in whom methotrexate is contraindicated or there is a failure in response - consider the administration of low doses of prednisone or equivalent (<7.5 mg/d) associated with DMARDc in patients with active moderate to severe RA, for the shortest possible time; perform serological control including tests for hepatitis B and C viruses and screening for HIV in all patients diagnosed with RA before starting treatment with DMARDc and biologics; in patients in remission or, at least, with a DAS-28 below 3.2, consideration should be given to withdrawing one of the DMARDs or reducing, to the minimum possible expression, the dose of both disease modifiers; if methotrexate fails, tocilizumab in combination with methotrexate or as monotherapy will be indicated. Conclusions: Aspects related to conventional therapy with methotrexate, azathioprine, salazosulfapyridine, antimalarials and leflunomide were agreed. The value of early diagnosis and immediate initiation of DMARDc therapy and the use of glucocorticoids was analyzed. Treatment with tocilizumab, the only biological available in Cuba against RA, will be administered when there is a failure in the response to conventional therapy and combinations between these drugs. It is recommended to hold educational conferences through the mass media aimed at patientshttp(AU)

Magnetotail reconnection onset caused by electron kinetics with a strong external driver.

Magnetotail reconnection plays a crucial role in explosive energy conversion in geospace. Because of the lack of in-situ spacecraft observations, the onset mechanism of magnetotail reconnection, however, has been controversial for decades. The key question is whether magnetotail reconnection is externally driven to occur first on electron scales or spontaneously arising from an unstable configuration on ion scales. Here, we show, using spacecraft observations and particle-in-cell (PIC) simulations, that magnetotail reconnection starts from electron reconnection in the presence of a strong external driver. Our PIC simulations show that this electron reconnection then develops into ion reconnection. These results provide direct evidence for magnetotail reconnection onset caused by electron kinetics with a strong external driver.

Minibeam radiation therapy at a conventional irradiator: Dose-calculation engine and first tumor-bearing animals irradiation.

PURPOSE: Minibeam radiation therapy (MBRT) is a novel therapeutic strategy, whose exploration was hindered due to its restriction to large synchrotrons. Our recent implementation of MBRT in a wide-spread small animal irradiator offers the possibility of performing systematic radiobiological studies. The aim of this research was to develop a set of dosimetric tools to reliably guide biological experiments in the irradiator. METHODS: A Monte Carlo (Geant4)-based dose calculation engine was developed. It was then benchmarked against a series of dosimetric measurements performed with gafchromic films. Two voxelized rat phantoms (ROBY, computer tomography) were used to evaluate the treatment plan of F98 tumor-bearing rats. The response of a group of 7 animals receiving a unilateral irradiation of 58 Gy was compared to a group of non-irradiated controls. RESULTS: The good agreement between calculations and the experimental data allowed the validation of the dose-calculation engine. The latter was first used to compare the dose distributions in computer tomography images of a rat's head and in a digital model of a rat's head (ROBY), obtaining a good general agreement. Finally, with respect to the in vivo experiment, the increase of mean survival time of the treated group with respect to the controls was modest but statistically significant. CONCLUSIONS: The developed dosimetric tools were used to reliably guide the first MBRT treatments of intracranial glioma-bearing rats outside synchrotrons. The significant tumor response obtained with respect to the non-irradiated controls, despite the heterogenous dose coverage of the target, might indicate the participation of non-targeted effects.

Spatial fractionation of the dose in heavy ions therapy: An optimization study.

PURPOSE: The alliance of charged particle therapy and the spatial fractionation of the dose, as in minibeam or Grid therapy, is an innovative strategy to improve the therapeutic index in the treatment of radioresistant tumors. The aim of this work was to assess the optimum irradiation configuration in heavy ion spatially fractionated radiotherapy (SFRT) in terms of ion species, beam width, center-to-center distances, and linear energy transfer (LET), information that could be used to guide the design of the future biological experiments. The nuclear fragmentation leading to peak and valley regions composed of different secondary particles, creates the need for a more complete dosimetric description that the classical one in SFRT. METHODS: Monte Carlo simulations (GATE 6.2) were performed to evaluate the dose distributions for different ions, beam widths, and spacings. We have also assessed the 3D-maps of dose-averaged LET and proposed a new parameter, the peak-to-valley-LET ratio, to offer a more thorough physical evaluation of the technique. RESULTS: Our results show that beam widths larger than 400 µm are needed in order to keep a ratio between the dose in the entrance and the dose in the target of the same order as in conventional irradiations. A large ctc distance (3500 µm) would favor tissue sparing since it provides higher PVDR, it leads to a reduced contribution of the heavier nuclear fragments and a LET value in the valleys a factor 2 lower than the LET in the ctc leading to homogeneous distributions in the target. CONCLUSIONS: Heavy ions MBRT provide advantageous dose distributions. Thanks to the reduced lateral scattering, the use of submillimetric beams still allows to keep a ratio between the dose in the entrance and the dose in the target of the same order as in conventional irradiations. Large ctc distances (3500 µm) should be preferred since they lead to valley doses composed of lighter nuclear fragments resulting in a much reduced dose-averaged LET values in normal tissue, favoring its preservation. Among the different ions species evaluated, Ne stands out as the one leading to the best balance between high PVDR and PVLR in normal tissues and high LET values (close to 100 keV/µm) and a favorable oxygen enhancement ratio in the target region.

In silico analysis of the competition between Streptococcus sanguinis and Streptococcus mutans in the dental biofilm.

During dental caries, the dental biofilm modifies the composition of the hundreds of involved bacterial species. Changing environmental conditions influence competition. A pertinent model to exemplify the complex interplay of the microorganisms in the human dental biofilm is the competition between Streptococcus sanguinis and Streptococcus mutans. It has been reported that children and adults harbor greater numbers of S. sanguinis in the oral cavity, associated with caries-free teeth. Conversely, S. mutans is predominant in individuals with a high number of carious lesions. Competition between both microorganisms stems from the production of H2 O2 by S. sanguinis and mutacins, a type of bacteriocins, by S. mutans. There is limited evidence on how S. sanguinis survives its own H2 O2 levels, or if it has other mechanisms that might aid in the competition against S. mutans, nonetheless. We performed a genomic and metabolic pathway comparison, coupled with a comprehensive literature review, to better understand the competition between these two species. Results indicated that S. sanguinis can outcompete S. mutans by the production of an enzyme capable of metabolizing H2 O2 . S. mutans, however, lacks the enzyme and is susceptible to the peroxide from S. sanguinis. In addition, S. sanguinis can generate energy through gluconeogenesis and seems to have evolved different communication mechanisms, indicating that novel proteins may be responsible for intra-species communication.

Transfer of Minibeam Radiation Therapy into a cost-effective equipment for radiobiological studies: a proof of concept.

Minibeam radiation therapy (MBRT) is an innovative synchrotron radiotherapy technique able to shift the normal tissue complication probability curves to significantly higher doses. However, its exploration was hindered due to the limited and expensive beamtime at synchrotrons. The aim of this work was to develop a cost-effective equipment to perform systematic radiobiological studies in view of MBRT. Tumor control for various tumor entities will be addressable as well as studies to unravel the distinct biological mechanisms involved in normal and tumor tissues responses when applying MBRT. With that aim, a series of modifications of a small animal irradiator were performed to make it suitable for MBRT experiments. In addition, the brains of two groups of rats were irradiated. Half of the animals received a standard irradiation, the other half, MBRT. The animals were followed-up for 6.5 months. Substantial brain damage was observed in the group receiving standard RT, in contrast to the MBRT group, where no significant lesions were observed. This work proves the feasibility of the transfer of MBRT outside synchrotron sources towards a small animal irradiator.

Validación de la escala inventario de estrategias de afrontamiento, versión Española de Cano, Rodríguez, García (2007), en el contexto de Panamá / Validation of coping strategy inventory scale, spanish version by Cano, Rodríguez, Garcia (2007), for Panama context

Las estrategias de afrontamiento son aquellos comportamientos y habilidades cognitivas utilizadas por las personas para afrontar o lidiar con demandas del ambiente interno y externo que son percibidos como estresantes. Las establecen las personas según su contexto situacional, y el objetivo es determinar la validez y confiabilidad del Inventario de Estrategias de Afrontamiento (Coping Strategies Inventory CSI), versión española de CanoGarcía, F. J.; Rodríguez Franco, L.; García Martínez, J. (1989), en el entorno de Panamá.El inventario aborda la conceptualización de afrontamiento según Lazarus, Richard S. desdela perspectiva de enfermería Roy, Sor Callista.Este estudio psicométrico, descriptivo, transaccional que indaga aspectos teóricos y de medición con un muestreo por conveniencia a una muestra aleatoria de 200 estudiantes de Licenciatura en Ciencias de Enfermería de la Universidad de Panamá durante exámenes finales del II semestre del 2015. El inventario conformado por 40 ítems y una auto evaluación de la eficacia. Las validaciones se realizaron considerando 5 estudiantes por ítem, totalizandola muestra de 200 estudiantes seleccionados., Se realiza el análisis con el coeficiente Alfa de Cronbach (mide consistencia interna) y Análisis Factorial Exploratorio (mide validez de constructo).Los resultados muestran un Alfa de Cronbach de 0,930. El análisis factorial arrojatres dimensiones: afrontamiento individual, busca ayuda en otros, y reprime y oculta sus sentimientos. La medida de adecuación de la muestra Kaiser-Meyer-Olkin (KMO) fue superior a 0.90. La prueba de esfericidad de Barlett resulta significativa (p-valor <0.001;contrasta la hipótesis nula: no existe relaciones entre variables).

Coping strategies are those behaviors and cognitive abilities used by people to copeor deal with demands of the internal and external environment that are perceived as stressful.They are established by people according to their situational context, and the objective is todetermine the validity and reliability of the Coping Strategies Inventory (CSI) a Spanishversion of Cano Garcia, F.J.; Rodriguez Franco, L.; Garcia Martinez, J. (1989) in Panama’ssurroundings.The inventory addresses the conceptualization of coping according to LazarusRichard S. from the Callista Roy’s nursing perspective.This psychometric, descriptive and transactional study investigates theoretical andmeasurable aspects with a sampling by convenience to a random sample of 200 students ofBachelor of Science in Nursing at the University of Panama during final exams of the secondsemester of 2015. The inventory consists of 40 items, and a self-assessment of effectiveness.Validations were made considering 5 students per item, totaling the selected sample of 200.The analysis is performed with the Cronbach’s Alpha coefficient (measuring internalconsistency) and Exploratory Factor Analysis (measuring construct validity).The results show a Cronbach’s Alpha of 0,930. The factor analysis presents threedimensions: individual coping, seeks help in others, and represses and hides feelings. TheKaiser-Meyer-Olkin measure of sampling adequacy (KMO) was above 0,90. The Barlettsphericity test is significant (p-value <0,001; contrasting the null hypothesis: there are norelationships between variables).The research concludes indicating that the validation and reliability of the scale isexcellent for the case of Panama. It is considered as an important methodological contributionfavoring further studies about the understanding of coping allowing to discover more aboutits meaning.

Introdução: as estratégias de afrontamento são aqueles comportamentos e habilidadescognitivas utilizadas pelas pessoas para afrontar o lidar com demandas do ambiente internoe externo que são percebidos como stress antes. São estabelecidas pelas pessoas segundo ocontexto situacional. Se pretende determinar a validade e confiabilidade do Inventário deEstratégias de Afrontamento (CSI, pelas siglas em inglês), versão em espanhol de Cano,Rodrigues e García (1989), no entorno de Panamá. O inventário aproxima a conceptualizaçãode afrontamento segundo Richard Lazarus. Desde Enfermagem Sor Callista Roy.Éumestudo metodológico psicométrico que indaga aspectos teóricos e de medição; aamostragem é por conveniência, a amostra aleatória de 200 estudantes de Bacharelado emCiências de Enfermagem da Universidade de Panamá durante provas semestrais do IIsemestre do ano 2015. O inventário conformado por 40 enunciados, e um adicional, medeauto avaliação da eficácia. A validação se realiza com mínimo de 5 estudantes por enunciado.Se realiza análise com o coeficiente Alfa de Cronbach (mede consistência interna) e AnáliseFactorial Exploratório (mede validade do constructo).Resultados: o Alfa de Cronbach foi de 0,930. A análise factorial deutrêsdimensões:afrontamento individual, procura ajudaemoutros e reprime e oculta os sentimentos. A medidade adequação da amostra KMO foi superior a 0,90. O teste de esfericidade de Barlett resultasignificativo (p-valor <0,001; contrasta a hipótese nula: não existe relação entre variáveis).Conclusões: a validade e confiabilidade da escala são excelentes para Panamá,considerando-se um aporte importante que favorece estudos sobre a compreensão doafrontamento que permitirá descobrir e conhecer o seu significado.

Stabilization Improves Theranostic Properties of Lipiodol®-Based Emulsion During Liver Trans-arterial Chemo-embolization in a VX2 Rabbit Model.

PURPOSE: To demonstrate that stability is a crucial parameter for theranostic properties of Lipiodol®-based emulsions during liver trans-arterial chemo-embolization. MATERIALS AND METHODS: We compared the theranostic properties of two emulsions made of Lipiodol® and doxorubicin in two successive animal experiments (One VX2 tumour implanted in the left liver lobe of 30 rabbits). Emulsion-1 reproduced one of the most common way of preparation (ratio of oil/water: 1/1), and emulsion-2 was designed to obtain a water-in-oil emulsion with enhanced stability (ratio of oil/water: 3/1, plus an emulsifier). The first animal experiment compared the tumour selectivity of the two emulsions: seven rabbits received left hepatic arterial infusion (HAI) of emulsion-1 and eight received HAI of emulsion-2. 3D-CBCT acquisitions were acquired after HAI of every 0.1 mL to measure the densities' ratios between the tumours and the left liver lobes. The second animal experiment compared the plasmatic and tumour doxorubicin concentrations after HAI of 1.5 mg of doxorubicin administered either alone (n = 3) or in emulsion-1 (n = 6) or in emulsion-2 (n = 6). RESULTS: Emulsion-2 resulted in densities' ratios between the tumours and the left liver lobes that were significantly higher compared to emulsion-1 (up to 0.4 mL infused). Plasmatic doxorubicin concentrations (at 5 min) were significantly lower after HAI of emulsion-2 (19.0 µg/L) than emulsion-1 (275.3 µg/L, p < 0.01) and doxorubicin alone (412.0 µg/L, p < 0.001), and tumour doxorubicin concentration (day-1) was significantly higher after HAI of emulsion-2 (20,957 ng/g) than in emulsion-1 (8093 ng/g, p < 0.05) and doxorubicin alone (2221 ng/g, p < 0.01). CONCLUSION: Stabilization of doxorubicin in a water-in-oil Lipiodol®-based emulsion results in better theranostic properties.

Exploring and understanding the functional role, and biochemical and structural characteristics of an acidic phospholipase A2, AplTx-I, purified from Agkistrodon piscivorus leucostoma snake venom.

Phospholipases A2 (PLA2s) constitute a class of extensively studied toxins, isolated from snake venoms. Basic PLA2 isoforms mediate various toxicological effects, while the acidic isoforms generally have higher enzymatic activities, but do not promote evident toxic effects. The functions of these acidic isoforms in snake venoms are still not completely understood and more studies are needed to characterize the biological functions and diversification of acidic toxins in order to justify their abundant presence in these secretions. Recently, Lomonte and collaborators demonstrated, in a proteomic and toxicological study, high concentrations of PLA2s in the venom of Agkistrodon piscivorus leucostoma. We have, herein, purified and characterized an acidic PLA2 from this snake venom, denominated AplTx-I, in order to better understand its biochemical and structural characteristics, as well as its biological effects. AplTx-I was purified using two chromatographic steps, in association with enzymatic and biological assays. The acidic toxin was found to be one of the most abundant proteins in the venom of A. p. leucostoma; the protein was monomeric with a molecular mass of 13,885.8 Da, as identified by mass spectrometry ESI-TOF and electrophoresis. The toxin has similar primary and tridimensional structures to those of other acidic PLA2s, a theoretical and experimental isoelectric point of ≈5.12, and a calcium-dependent enzyme activity of 25.8985 nM/min/mg, with maximum values at 37 °C and pH 8.0. Despite its high enzymatic activity on synthetic substrate, AplTx-I did not induce high or significant myotoxic, coagulant, anticoagulant, edema, neuromuscular toxicity in mouse phrenic nerve-diaphragm preparations or antibacterial activities. Interestingly, AplTx-I triggered a high and selective neuromuscular toxicity in chick biventer cervicis preparations. These findings are relevant to provide a deeper understanding of the pharmacology, role and diversification of acidic phospholipase A2 isoforms in snake venoms.

CoaTx-II, a new dimeric Lys49 phospholipase A2 from Crotalus oreganus abyssus snake venom with bactericidal potential: Insights into its structure and biological roles.

Snake venoms are rich and intriguing sources of biologically-active molecules that act on target cells, modulating a diversity of physiological functions and presenting promising pharmacological applications. Lys49 phospholipase A2 is one of the multifunctional proteins present in these complex secretions and, although catalytically inactive, has a variety of biological activities, including cytotoxic, antibacterial, inflammatory, antifungal activities. Herein, a Lys49 phospholipase A2, denominated CoaTx-II from Crotalus oreganus abyssus, was purified and structurally and pharmacologically characterized. CoaTx-II was isolated with a high degree of purity by a combination of two chromatographic steps; molecular exclusion and reversed-phase high performance liquid chromatography. This toxin is dimeric with a mass of 13868.2 Da (monomeric form), as determined by mass spectrometry. CoaTx-II is rich in Arg and Lys residues and displays high identity with other Lys49 PLA2 homologues, which have high isoelectric points. The structural model of dimeric CoaTx-II shows that the toxin is non-covalently stabilized. Despite its enzymatic inactivity, in vivo CoaTx-II caused local muscular damage, characterized by increased plasma creatine kinase and confirmed by histological alterations, in addition to an inflammatory activity, as demonstrated by mice paw edema induction and pro-inflammatory cytokine IL-6 elevation. CoaTx-II also presents antibacterial activity against gram negative (Pseudomonas aeruginosa 31NM, Escherichia coli ATCC 25922) and positive (Staphyloccocus aureus BEC9393 and Rib1) bacteria. Therefore, data show that this newly purified toxin plays a central role in mediating the degenerative events associated with envenomation, in addition to demonstrating antibacterial properties, with potential for use in the development of strategies for antivenom therapy and combating antibiotic-resistant bacteria.

El afrontamiento al estrés académico en los estudiantes de enfermería / Coping with academic stress in nursing students

La Organización Mundial de la Salud (OMS) define el estrés como el conjunto de reacciones fisiológicas queprepara el organismo para la acción. Otros autores lo definen como un conjunto de reacciones fisiológicas ypsicológicas que experimenta el organismo cuando es sometido a fuertes demandas. En el mundo, algunaspersonas, como ocurre en algunos países industrializados y en vías de desarrollo sufren de problema de estrés,relacionados a la crisis mundial de valores y a las situaciones económicas, sociales y culturales críticas en dondeuna de cada cuatro persona sufre de algún problema grave de estrés, el 50% de las personas que presentan algunaenfermedad es debido al estrés.El estrés como factor epidemiológico, es un indicador de riesgo a la salud, ya que genera diversas patologías quesuele clasificarse en categorías según su fuente en estrés académico y estrés laboral. El estrés académico sepresenta desde los grados preescolares, en la educación superior y los postgrados y definiéndose de varias formasentre las que se considera como una reacción de activación fisiológica, emocional, cognitiva y conductual anteestímulos y eventos académicos, otros como: Lazarus y Folkman señalan que una persona que está en el períodode aprendizaje experimenta tensión, la cual se denomina estrés académico, y ocurre tanto en el estudio individualcomo en el aula escolar.El profesional de enfermería desde su formación viene afrontando situaciones o eventos estresantes propios de lacarrera, por ejemplo la responsabilidad de exposiciones y entrega de tareas así como también actividadesacadémicas y de práctica, que a medida que van avanzando en la carrera, se vuelven más complejas por lo tantose presentan estresantes y desde ésta etapa el estudiante debe aprender cómo afrontarlos para que no pueda afectarsu estado físico y emocional como futuro profesional.

According with the World Health Organization (WHO) defines the concept stress as physiological reactionsof organism preparing for the action. Other authors, define this concept as several physiological andpsychological reactions of an organism when is summated to grate demands.In the world, some person, confront stressed situations related to world crisis of values and economic, socialand critical cultural situations were from each four, person one suffers some kind of stress problems, the50% of the people have some kind of stress related disease.The academic stress is presented in children from preschool, hire education, and in graduate studies, withmanifestations of physiological reactions, emotional, cognitive and behavioral as response to stimulus andacademic events.Other stress as epidemiological factor, is an indicator of some kind of risk factor that affects health of thepopulation, due that generate diver’s pathologies and could be categorize according with the sources asacademic stress and labor stress.This academic stress is developed since preschool years to higher education, and post graduate studies. Themanifestations area responds to the stimuli in academic events.The professionals of nursing since there academic formation in nursing studies cope with stressorsexperiences, situations and events natural of their career studies. For example: responsibilities of exposurein real clinical practice and preparing their writing reports of their clinical activities that become morecomplex that result in increasing levels of stress from medium, to high levels of stress.

A Organização Mundial da Saúde define o estresse como o conjunto de reações fisiológicas que prepara oorganismo para a ação; outros autores definem isto como um conjunto de reações fisiológicas e psicológicasque experimenta o organismo quando é submetido a fortes demandas. No mundo, as pessoas se vêmenfrentadas a situações de estresse, relacionadas à crise mundial de valores, a situações econômicas, sociaise culturais críticas, onde um de cada quatro indivíduos sofre de algum problema grave de estresse. Nascidades se acredita que o 50% das pessoas tem algum problema de saúde mental devido ao estresse.O estresse como fator epidemiológico é um indicador de risco para a saúde, já que pode gerar diversaspatologias que podem ser categorizadas segundo a fonte em estresse acadêmico e estresse laboral: quandose apresenta em estudantes em centros educativos é conhecido como estresse acadêmico e quando seapresenta a nível organizacional e institucional se considera como estresse laboral.O estresse acadêmico aparece desde o contexto pré-escolar, pré grau e pós grau, se manifestando comoreação de ativação fisiológica, emocional, cognitiva e condutual frente a estímulos e eventos acadêmicosque provocam tensão. O profissional da enfermagem desde sua formação afronta situações o eventos deestresse próprios da carreira, por exemplo, a responsabilidade de exposições e entrega de trabalhos, assimcomo atividades acadêmicas e de prática, que a medida que avança a carreira se tornam mais complexasdesencadeando um nível de estresse meio - alto.

Semiclassical Wigner theory of photodissociation in three dimensions: Shedding light on its basis.

The semiclassical Wigner theory (SCWT) of photodissociation dynamics, initially proposed by Brown and Heller [J. Chem. Phys. 75, 186 (1981)] in order to describe state distributions in the products of direct collinear photodissociations, was recently extended to realistic three-dimensional triatomic processes of the same type [Arbelo-González et al., Phys. Chem. Chem. Phys. 15, 9994 (2013)]. The resulting approach, which takes into account rotational motions in addition to vibrational and translational ones, was applied to a triatomic-like model of methyl iodide photodissociation and its predictions were found to be in nearly quantitative agreement with rigorous quantum results, but at a much lower computational cost, making thereby SCWT a potential tool for the study of polyatomic reaction dynamics. Here, we analyse the main reasons for this agreement by means of an elementary model of fragmentation explicitly dealing with the rotational motion only. We show that our formulation of SCWT makes it a semiclassical approximation to an approximate planar quantum treatment of the dynamics, both of sufficient quality for the whole treatment to be satisfying.

Toxins and virulence factors of enterotoxigenic Escherichia coli associated with strains isolated from indigenous children and international visitors to a rural community in Guatemala.

Diarrhoea remains a common cause of illness in Guatemala, with children suffering most frequently from the disease. This study directly compared the frequency, enterotoxin, and colonization factor (CF) profiles of enterotoxigenic Escherichia coli (ETEC) strains isolated from children living in a rural community in Guatemala and from Western visitors to the same location during the same seasons, using similar detection methodologies. We found that ETEC accounted for 26% of severe cases of diarrhoea in children requiring hospitalization, 15% of diarrhoea in the community, and 29% of travellers' diarrhoea in visitors staying ⩾2 weeks. The toxin and CF patterns of the ETEC strains isolated from both groups differed significantly (P < 0·0005) as determined by χ 2 = 60·39 for CFs and χ 2 = 35 for toxins, while ETEC phenotypes found in Guatemalan children were comparable to those found in children from other areas of the world.

Sulfonylurea receptor 1 contributes to the astrocyte swelling and brain edema in acute liver failure.

Astrocyte swelling (cytotoxic brain edema) is the major neurological complication of acute liver failure (ALF), a condition in which ammonia has been strongly implicated in its etiology. Ion channels and transporters are known to be involved in cell volume regulation, and a disturbance in these systems may result in cell swelling. One ion channel known to contribute to astrocyte swelling/brain edema in other neurological disorders is the ATP-dependent, nonselective cation (NCCa-ATP) channel. We therefore examined its potential role in the astrocyte swelling/brain edema associated with ALF. Cultured astrocytes treated with 5 mM ammonia showed a threefold increase in the sulfonylurea receptor type 1 (SUR1) protein expression, a marker of NCCa-ATP channel activity. Blocking SUR1 with glibenclamide significantly reduced the ammonia-induced cell swelling in cultured astrocytes. Additionally, overexpression of SUR1 in ammonia-treated cultured astrocytes was significantly reduced by cotreatment of cells with BAY 11-7082, an inhibitor of NF-κB, indicating the involvement of an NF-κB-mediated SUR1 upregulation in the mechanism of ammonia-induced astrocyte swelling. Brain SUR1 mRNA level was also found to be increased in the thioacetamide (TAA) rat model of ALF. Additionally, we found a significant increase in SUR1 protein expression in rat brain cortical astrocytes in TAA-treated rats. Treatment with glibenclamide significantly reduced the brain edema in this model of ALF. These findings strongly suggest the involvement of NCCa-ATP channel in the astrocyte swelling/brain edema in ALF and that targeting this channel may represent a useful approach for the treatment of the brain edema associated with ALF.

New insights into the semiclassical Wigner treatment of photodissociation dynamics.

The semiclassical Wigner treatment of Brown and Heller [J. Chem. Phys. 1981, 75, 186] is applied to direct triatomic (or triatomic-like polyatomic) photodissociations with the aim of accurately predicting final state distributions at relatively low computational cost, and having available a powerful interpretative tool. For the first time, the treatment takes rotational motions into account. The proposed formulation closely parallels the quantum description as far as possible. An approximate version is proposed, which is still accurate while numerically much more efficient. In addition to being weighted by usual vibrational Wigner distributions, final phase space states appear to be weighted by new rotational Wigner distributions. These densities have remarkable structures clearly showing that classical trajectories most contributing to rotational state j are those reaching the products with a rotational angular momentum close to [j(j + 1)](1/2) (in ℏ units). The previous methods involve running trajectories from the reagent molecule onto the products. The alternative backward approach [L. Bonnet, J. Chem. Phys., 2010, 133, 174108], in which trajectories are run in the reverse direction, is shown to strongly improve the numerical efficiency of the most rigorous method in addition to being state-selective, and thus, ideally suited to the description of state-correlated distributions measured in velocity imaging experiments. The results obtained by means of the previous methods are compared with rigorous quantum results in the case of Guo's triatomic-like model of methyl iodide photodissociation [J. Chem. Phys., 1992, 96, 6629] and close agreement is found. In comparison, the standard method of Goursaud et al. [J. Chem. Phys., 1976, 65, 5453] is only semi-quantitative.

Exploring child maltreatment and its relationship to alcohol and cannabis use in selected Latin American and Caribbean countries.

OBJECTIVES: Research from developed countries shows that child maltreatment increases the risk for substance use and problems. However, little evidence on this relationship is available from developing countries, and recognition of this relationship may have important implications for substance demand reduction strategies, including efforts to prevent and treat substance use and related problems. Latin America and the Caribbean is a rich and diverse region of the world with a large range of social and cultural influences. A working group constituted by the Inter-American Drug Abuse Control Commission and the Center for Addiction and Mental Health in June, 2010 identified research on this relationship as a priority area for a multinational research partnership. METHODS: This paper examines the association between self-reported child maltreatment and use in the past 12 months of alcohol and cannabis in 2294 university students in seven participating universities in six participating countries: Colombia, El Salvador, Jamaica, Nicaragua, Panama and Uruguay. The research also considers the possible impact of religiosity and minimal psychological distress as factors contributing to resiliency in these samples. RESULTS: The results showed that experience of maltreatment was associated with increased use of alcohol and cannabis. However, the effects differed depending on the type of maltreatment experienced. Higher levels of religiosity were consistently associated with lower levels of alcohol and cannabis use, but we found no evidence of an impact of minimal psychological distress on these measures. CONCLUSIONS: This preliminary study shows that the experience of maltreatment may increase the risk of alcohol and cannabis use among university students in Latin American and Caribbean countries, but that higher levels of religiosity may reduce that risk. More work to determine the nature and significance of these relationships is needed.

Monte Carlo simulation of the dynamic micro-multileaf collimator of a LINAC Elekta Precise using PENELOPE.

Micro-multileaf collimators are devices that are added to LINAC heads for stereotactic radiosurgery. In this work, the performance of an Elekta Precise LINAC with a dynamic micro-multileaf collimator manufactured by 3D-line has been studied. Monte Carlo simulations based on PENELOPE code and measurements with three different detectors (PTW Semiflex 31010 chamber, PTW PinPoint 31016 chamber and PTW Diode 60008) have been carried out. Simulations were tuned by reproducing the experimental TPR(20, 10) quality index, providing a nice description of both the PDD curve and the transverse profiles at the two depths measured. The geometry of the micro-multileaf collimator was tested by calculating the transmission through it, and it was needed to significantly reduce the leaf separation indicated by the manufacturer to reproduce the experimental results. An approximate simulation in which the transport of the particles traversing the dynamic micro-multileaf collimator was described in a simplified way was analyzed, providing good agreement with the full simulations. With the MC model fixed, output factors for various field sizes were calculated and compared to the experimental ones, obtaining good agreement. Percentage depth doses (PDDs) and transverse profiles at two depths measured with the diode for small fields were well reproduced by the simulation, while the measurements performed with the PinPoint chamber showed differences in the PDDs, at large depths, and transverse profiles, at the penumbra. Monte Carlo simulations and Semiflex and diode measurements, performed for a 7.0 cm × 7.0 cm field, were in nice agreement, while those obtained with the PinPoint chamber showed differences that increased with the depth in water. At the phantom entrance, all measurements showed non-negligible differences that made Monte Carlo a good option to estimate the absorbed dose in this region.

Selection of variables using factorial discriminant analysis for the state identification of an anaerobic UASB-UAF hybrid pilot plant, fed with winery effluents.

Anaerobic wastewater treatment has become a widely used method for wastewater depuration, and has been applied in a wide range of situations, from urban wastewater to highly toxic industrial wastewater. Particularly it has been successfully applied to the treatment of the beverage industries effluents. To avoid the destabilization of the system a monitoring diagnosis and control system of the depuration processes is necessary. The cost of this system is an important issue, that depends on the number of parameters that must be controlled for an adequate performance of a wastewater plant control system. This work shows how the classic statistical classification techniques can be applied to determine the number variables that must be monitored to achieve an adequate performance of anaerobic UASB-UAF hybrid Pilot Plant monitoring and control system. The obtained results had not been unique, so different combinations of variables can be selected for a good wastewater treatment process control. Economic or technical criteria may be considered to determine the final variables set in each particular situation.

An unusual case of thermal injuries with a hot glue gun. Deliberate self-harm or maltreatment?

Assessing injuries in forensic medicine casework, examiners are often confronted with the question of self-infliction versus third parties' influence, respectively, deliberate self-harm versus maltreatment. We report the case of a 40-year-old male who presented with numerous partially healed thermal injuries of different age. These burns were shaped like capital letters and little circles, which were arranged in lines in a regular form. The lesions were found on the whole body with exclusion of face, genitals, hands and feet. Furthermore, four bitemarks at the right shoulder were noted. Investigations revealed that the man had been abused by his 25-year-old wife (presumably a borderline personality disorder patient) for at least 1 year. In addition to another series of abuses, the woman may have inflicted the shaped burns with a hot glue gun as punishment for breaking certain "rules" she had established. When assessing injuries of patients in forensic medicine, several considerations regarding etiology have to be taken into account. In principle, the victim's testimony, the anamnesis, the police investigation results and the findings from the forensic physical examination have to be balanced against each other. The injury pattern in the present case showed contradictory single characteristics both of deliberate self-harm and of maltreatment. After forensic analysis, it was assessed as injuries inflicted by an assistant with the patient's consent.