Glucosylceramides impact cellulose deposition and cellulose synthase complex motility in Arabidopsis.

Cellulose is an abundant component of plant cell wall matrices, and this para-crystalline polysaccharide is synthesized at the plasma membrane by motile Cellulose Synthase Complexes (CSCs). However, the factors that control CSC activity and motility are not fully resolved. In a targeted chemical screen, we identified the alkylated nojirimycin analog N-Dodecyl Deoxynojirimycin (ND-DNJ) as a small molecule that severely impacts Arabidopsis seedling growth. Previous work suggests that ND-DNJ-related compounds inhibit the biosynthesis of glucosylceramides (GlcCers), a class of glycosphingolipid associated with plant membranes. Our work uncovered major changes in the sphingolipidome of plants treated with ND-DNJ, including reductions in GlcCer abundance and altered acyl chain length distributions. Crystalline cellulose content was also reduced in ND-DNJ-treated plants as well as plants treated with the known GlcCer biosynthesis inhibitor N-[2-hydroxy-1-(4-morpholinylmethyl)-2-phenyl ethyl]-decanamide (PDMP) or plants containing a genetic disruption in GLUCOSYLCERAMIDE SYNTHASE (GCS), the enzyme responsible for sphingolipid glucosylation that results in GlcCer synthesis. Live-cell imaging revealed that CSC speed distributions were reduced upon treatment with ND-DNJ or PDMP, further suggesting an important relationship between glycosylated sphingolipid composition and CSC motility across the plasma membrane. These results indicate that multiple interventions compromising GlcCer biosynthesis disrupt cellulose deposition and CSC motility, suggesting that GlcCers regulate cellulose biosynthesis in plants.

High-throughput profiling of histone post-translational modifications and chromatin modifying proteins by reverse phase protein array.

Epigenetic variation plays a significant role in normal development and human diseases including cancer, in part through post-translational modifications (PTMs) of histones. Identification and profiling of changes in histone PTMs, and in proteins regulating PTMs, are crucial to understanding diseases, and for discovery of epigenetic therapeutic agents. In this study, we have adapted and validated an antibody-based reverse phase protein array (RPPA) platform for profiling 20 histone PTMs and expression of 40 proteins that modify histones and other epigenomic regulators. The specificity of the RPPA assay for histone PTMs was validated with synthetic peptides corresponding to histone PTMs and by detection of histone PTM changes in response to inhibitors of histone modifier proteins in cell cultures. The useful application of the RPPA platform was demonstrated with two models: induction of pluripotent stem cells and a mouse mammary tumor progression model. Described here is a robust platform that includes a rapid microscale method for histone isolation and partially automated workflows for analysis of histone PTMs and histone modifiers that can be performed in a high-throughput manner with hundreds of samples. This RPPA platform has potential for translational applications through the discovery and validation of epigenetic states as therapeutic targets and biomarkers. SIGNIFICANCE: Our study has established an antibody-based reverse phase protein array platform for global profiling of a wide range of post-translational modifications of histones and histone modifier proteins. The high-throughput platform provides comprehensive analyses of epigenetics for biological research and disease studies and may serve as screening assay for diagnostic purpose or therapy development.

Pros and cons of innovations in medical education.

Medical education has implemented various innovative strategies with the purpose to attain better learning achievements. An evaluation is made of the experiences in the competencies approach, new learning technologies, curricular alternatives, professional evaluation and distance education technologies in order to locate them in the areas they belong.

La educación médica ha puesto en práctica diversas estrategias innovadoras con el propósito de alcanzar mejores logros de aprendizaje. Se hace una evaluación de las experiencias relacionadas con el enfoque por competencias, las nuevas tecnologías educativas, las alternativas curriculares, la profesionalización de la evaluación y las técnicas educativas a distancia, para ubicarlas en el lugar que les corresponde.

Pros y contras de las innovaciones en educación médica / Pros and cons of innovations in medical education

Resumen La educación médica ha puesto en práctica diversas estrategias innovadoras con el propósito de alcanzar mejores logros de aprendizaje. Se hace una evaluación de las experiencias relacionadas con el enfoque por competencias, las nuevas tecnologías educativas, las alternativas curriculares, la profesionalización de la evaluación y las técnicas educativas a distancia, para ubicarlas en el lugar que les corresponde.

Abstract Medical education has implemented various innovative strategies with the purpose to attain better learning achievements. An evaluation is made of the experiences in the competencies approach, new learning technologies, curricular alternatives, professional evaluation and distance education technologies in order to locate them in the areas they belong.

Psychometric Properties of the Schizotypal Personality Questionnaire (SPQ) in a Mexican Population: Invariance Across Gender and Age.

BACKGROUND: The present study tested the factorial structure of the Schizotypal Personality Questionnaire (SPQ) in Mexican adults. Although this instrument has been validated in different cultural contexts, there are no studies to date that analyze its psychometric properties in a Mexican sample. METHOD: 307 adults completed the SPQ, seven participants were removed for being at high risk of psychosis. The final sample was made up of 300 participants (M = 34.58, SD = 13.77), of whom 62.8% were female. Raine's three-factor model and Stefanis et al.'s four-factor model were tested. RESULTS: The results indicated that both factor structures had a good fit to the data. However, the best evidence was for the three-factor solution. Configural, metric, and scalar invariance according to gender and age for the three-factor model was displayed. Further analyses showed women scored slightly higher in excessive social anxiety but this result was not statistically significant. Younger participants had higher scores on ideas of reference, excessive social anxiety, no close friends, and odd speech than the older group. CONCLUSIONS: These findings provide support for the use of the SPQ in the Mexican population.

Cognitive deterioration in schizophrenia: aging and cerebrovascular disease.

Today, cognitive dysfunction is accepted as a feature of schizophrenia. As the patients age, this dysfunction is higher and harder to evaluate due to the interaction among aging, other somatic diseases, psychoactive drugs, etc.

BRASSINOSTEROID INSENSITIVE2 negatively regulates cellulose synthesis in Arabidopsis by phosphorylating cellulose synthase 1.

The deposition of cellulose is a defining aspect of plant growth and development, but regulation of this process is poorly understood. Here, we demonstrate that the protein kinase BRASSINOSTEROID INSENSITIVE2 (BIN2), a key negative regulator of brassinosteroid (BR) signaling, can phosphorylate Arabidopsis cellulose synthase A1 (CESA1), a subunit of the primary cell wall cellulose synthase complex, and thereby negatively regulate cellulose biosynthesis. Accordingly, point mutations of the BIN2-mediated CESA1 phosphorylation site abolished BIN2-dependent regulation of cellulose synthase activity. Hence, we have uncovered a mechanism for how BR signaling can modulate cellulose synthesis in plants.

The 2009 pandemic in Mexico: Experience and lessons regarding national preparedness policies for seasonal and epidemic influenza.

Influenza is a viral respiratory disease capable of causing epidemics that represent a threat for global security. Mexico was the first country to notify the WHO of an outbreak of what later became the first influenza pandemic of the 21st Century, caused by the virus A(H1N1)2009. Before this event Mexico had a national pandemic influenza preparedness plan, which included seasonal influenza vaccination, stockpiles of personal protection equipment and strategic drugs, and risk communication strategies. During the epidemic, the national public health laboratory network and case surveillance systems were strengthened together with surge capacities for intensive care and delivery of antiviral drugs. Risk communication was conducted for people to comply with implemented measures regarding social distancing (workplace and school closures, household quarantine). This report describes the Mexican experience during the 2009 influenza pandemic and the lessons that this experience provides to public health preparedness for future pandemics.

Criterion validity and clinical usefulness of Attention Deficit Hyperactivity Disorder Rating Scale IV in attention deficit hyperactivity disorder (ADHD) as a function of method and age.

BACKGROUND: The aim of this research is to analyze Attention Deficit Hyperactivity Disorder Rating Scales IV (ADHD RS-IV) criteria validity and its clinical usefulness for the assessment of Attention Deficit Hyperactivity Disorder (ADHD) as a function of assessment method and age. METHODOLOGY: A sample was obtained from an epidemiological study (n = 1095, 6-16 years). Clinical cases of ADHD (ADHD-CL) were selected by dimensional ADHD RS-IV and later by clinical interview (DSM-IV). ADHD-CL cases were compared with four categorical results of ADHD RS-IV provided by parents (CATPA), teachers (CATPR), either parents or teachers (CATPAOPR) and both parents and teachers (CATPA&PR). Criterion validity and clinical usefulness of the answer modalities to ADHD RS-IV were studied. RESULTS: ADHD-CL rate was 6.9% in childhood, 6.2% in preadolescence and 6.9% in adolescence. Alternative methods to the clinical interview led to increased numbers of ADHD cases in all age groups analyzed, in the following sequence: CATPAOPR> CATPRO> CATPA> CATPA&PR> ADHD-CL. CATPA&PR was the procedure with the greatest validity, specificity and clinical usefulness in all three age groups, particularly in the childhood. CONCLUSIONS: Isolated use of ADHD RS-IV leads to an increase in ADHD cases compared to clinical interview, and varies depending on the procedure used.

The Emerging Role of Protein Phosphorylation as a Critical Regulatory Mechanism Controlling Cellulose Biosynthesis.

Plant cell walls are extracellular matrices that surround plant cells and critically influence basic cellular processes, such as cell division and expansion. Cellulose is a major constituent of plant cell walls, and this paracrystalline polysaccharide is synthesized at the plasma membrane by a large protein complex known as the cellulose synthase complex (CSC). Recent efforts have identified numerous protein components of the CSC, but relatively little is known about regulation of cellulose biosynthesis. Numerous phosphoproteomic surveys have identified phosphorylation events in CSC associated proteins, suggesting that protein phosphorylation may represent an important regulatory control of CSC activity. In this review, we discuss the composition and dynamics of the CSC in vivo, the catalog of CSC phosphorylation sites that have been identified, the function of experimentally examined phosphorylation events, and potential kinases responsible for these phosphorylation events. Additionally, we discuss future directions in cellulose synthase kinase identification and functional analyses of CSC phosphorylation sites.

Prevalence of Oppositional Defiant Disorder in a sample of Spanish children between six and sixteen years: teacher’s report.

INTRODUCTION: Our main objective is to study the prevalence of Oppositional Defiant Disorder (ODD) in school children aged 6-16 years of an autonomous region of Spain (Castile and Leon), according to reports from the teachers and to analyze the impact of the disorder on academic performance and school behavior. METHODS: Population study with stratified multistage, proportional and cluster design sample. Sample analyzed: 1,049. Cases were defined according to DSM-IV-TR criteria. RESULTS: An overall prevalence rate of 4.2% was found, this being significantly higher in males (5.7%) compared to females (2.6%) and in rural (6.8%) than in urban areas (3%). No significant differences by grade or type of school were found. ODD prevalence without considering functional impairment would increase to 5.1%. ODD cases have significantly worse academic outcomes (overall academic performance, reading, math and writing) and entail worse classroom behavior (relationship with peers, respect for rules, organizational skills, academic tasks and disruption of the class). CONCLUSIONS: Based on the prevalence, early onset, persistence of symptoms and social and academic dysfunction of ODD, early diagnosis and preventive intervention are necessary.

Surveillance of Oseltamivir-Resistant Influenza A(H1N1)pdm09 in Guanajuato State, Mexico from 2009 to 2012.

BACKGROUND: The influenza A(H1N1)pdm09 virus was first identified in Mexico in April 2009, subsequently spreading worldwide. Soon after the WHO declared a pandemic, a series of cases involving oseltamivir-resistant viruses were described, following concerns about the spread of strains resistant to neuraminidase inhibitors that could hamper control measures. To study the prevalence of oseltamivir-resistant influenza A(H1N1)pdm09, we implemented a surveillance program across the state of Guanajuato, Mexico. METHODS: We collected respiratory samples from patients with confirmed infection with influenza A(H1N1)pdm09 virus between 2009 and 2012 in rural and urban regions in Guanajuato, Mexico. Specimens were screened for the H275Y mutation by Sanger sequencing. RESULTS: A total of 1,192 laboratory confirmed influenza A(H1N1)pdm09-positive samples were processed between 2009 and 2012. Using two endpoint real-time polymerase chain reaction, 575 samples were sequenced. Two different clusters, I and II, were identified. The H275Y substitution was found in only one sample from cluster I. CONCLUSIONS: The prevalence of oseltamivir-resistant influenza A(H1N1)pdm09 2009 viruses during the pandemic period and following years was very low in our State.

2-Fluoro-L-Fucose Is a Metabolically Incorporated Inhibitor of Plant Cell Wall Polysaccharide Fucosylation.

The monosaccharide L-fucose (L-Fuc) is a common component of plant cell wall polysaccharides and other plant glycans, including the hemicellulose xyloglucan, pectic rhamnogalacturonan-I (RG-I) and rhamnogalacturonan-II (RG-II), arabinogalactan proteins, and N-linked glycans. Mutations compromising the biosynthesis of many plant cell wall polysaccharides are lethal, and as a result, small molecule inhibitors of plant cell wall polysaccharide biosynthesis have been developed because these molecules can be applied at defined concentrations and developmental stages. In this study, we characterize novel small molecule inhibitors of plant fucosylation. 2-fluoro-L-fucose (2F-Fuc) analogs caused severe growth phenotypes when applied to Arabidopsis seedlings, including reduced root growth and altered root morphology. These phenotypic defects were dependent upon the L-Fuc salvage pathway enzyme L-Fucose Kinase/ GDP-L-Fucose Pyrophosphorylase (FKGP), suggesting that 2F-Fuc is metabolically converted to the sugar nucleotide GDP-2F-Fuc, which serves as the active inhibitory molecule. The L-Fuc content of cell wall matrix polysaccharides was reduced in plants treated with 2F-Fuc, suggesting that this molecule inhibits the incorporation of L-Fuc into these polysaccharides. Additionally, phenotypic defects induced by 2F-Fuc treatment could be partially relieved by the exogenous application of boric acid, suggesting that 2F-Fuc inhibits RG-II biosynthesis. Overall, the results presented here suggest that 2F-Fuc is a metabolically incorporated inhibitor of plant cellular fucosylation events, and potentially suggest that other 2-fluorinated monosaccharides could serve as useful chemical probes for the inhibition of cell wall polysaccharide biosynthesis.

Clinical characteristics of fatalities due to influenza A (H1N1) virus in Mexico.

BACKGROUND: Mexico has experienced a disproportionate mortality burden due to the influenza A(HIN1) pandemic. A study was undertaken to investigate the sociodemographic and clinical characteristics of the first 100 patients who died from confirmed influenza A(H1N1). METHODS: A clinical evaluation was made of the first 100 consecutive deaths of confirmed cases between 10 April and 28 May 2009 reported by the Federal Ministry of Health. Statistical analysis included disease frequencies and descriptive comparisons with national health data. RESULTS: Most patients (60%) were aged 30-79 years, 53% were female and 40% were residents of Mexico City. On admission, 50% had one or more chronic medical conditions including metabolic syndrome (40%), cardiovascular disease (21%), diabetes (20%), hypertension (20%) and respiratory disease (8%). 38% of women and 26% of men were obese based on body mass index). The main clinical symptoms were fever (84%), cough (85%), dyspnoea (75%) and myalgia (30%). The frequency of all chronic diseases was higher in this sample than in the national statistics. Most (82%) developed symptoms before the Mexican government issued the influenza alert (24 April). Median hospital stay prior to death was 4 days (range 0-58). CONCLUSIONS: Patients, mostly young adults, who died from A(HIN1) influenza had a high frequency of one or more chronic diseases upon admission. Most died shortly after the health authorities initiated national influenza control measures.

[Influenza A H1N1 (2009): considerations at the time of declaring the end of the contingency in Mexico]. / La influenza A H1N1 (2009): el recuento al declararse el término de la contingencia en México.

We review important aspects of the pandemic influenza A (H1N1) at the time of declaring the end of the contingency in Mexico. The pre-established surveillance system had to be modified during the course of the epidemic. From the first epidemic weeks, viral monitoring recorded the displacement of other pathogens by the pandemic virus. Patients at high risk for complications were identified together with the need for early treatment with antiviral drugs, thus avoiding the saturation of intensive care beds. The difficulties of surging services for seriously ill patients are described. Preventive measures such as the use of masks and hand hygiene are reviewed, as well as the vaccination drive and the difficulties for its application in health personnel. The review concludes with the need to learn the teachings of the pandemic, describing the necessary elements to prepare against the next one.

The influenza A(H1N1) epidemic in Mexico. Lessons learned.

Several influenza pandemics have taken place throughout history and it was assumed that the pandemic would emerge from a new human virus resulting from the adaptation of an avian virus strain. Mexico, since 2003 had developed a National Preparedness and Response Plan for an Influenza Pandemic focused in risk communication, health promotion, healthcare, epidemiological surveillance, strategic stockpile, research and development. This plan was challenged on April 2009, when a new influenza A(H1N1) strain of swine origen was detected in Mexico. The situation faced, the decisions and actions taken, allowed to control the first epidemic wave in the country. This document describes the critical moments faced and explicitly point out the lessons learned focused on the decided support by the government, the National Pandemic Influenza Plan, the coordination among all the government levels, the presence and solidarity of international organizations with timely and daily information, diagnosis and the positive effect on the population following the preventive hygienic measures recommended by the health authorities. The international community will be able to use the Mexican experience in the interest of global health.