Differences in the effects of a startle stimulus on rate of force development between resistance-trained rock climbers and untrained individuals: Evidence for reticulospinal adaptations?

The aim of the present cross-sectional study was to determine if chronic rock climbing and climbing-specific resistance training (RT) would modify the reticulospinal tract (RST) efficacy. Sixteen healthy, elite level climbers (CL; n = 16, 5 F; 29.8 ± 6.7 years) with 12 ± 7 years of climbing and climbing-specific RT experience and 15 healthy recreationally active participants (CON; n = 15, 4 F; 24.6 ± 5.9 years), volunteered for the study. We quantified RST efficacy by comparing the effects of a startle stimulus over reaction time (Rtime ) and measured rate of force development (RFD) and surface electromyography (sEMG) in representative muscles during powerful hand grip contractions. Both groups performed two Rtime tasks while performing rapid, powerful gripping with the right hand (Task 1) or during 3-s-long maximal voluntary right hand grip contractions in response to an imperative visual signal alone (V), or combined with a auditory-non startle stimulus (A) or/and startling auditory stimulus (S). We also tested the reproducibility of these responses on two separate days in CON. Intersession reliability ranged from 0.34 to 0.96 for all variables. The CL versus CON was 37% stronger (p = 0.003). The S stimulus decreased Rtime and increased RFD and sEMG in both groups during both tasks (all p < 0.001). Rtime was similar between groups in all conditions. However, CL had a greater RFD from 50 to 100 ms compared with CON only after the S stimulus in both tasks (p < 0.05, d = 0.85-0.96). The data tentatively suggest that chronic rock climbing and climbing-specific RT might improve RST efficacy, by increasing RST input to the α-motoneurons.

Which is the most reliable edge depth to measure maximum hanging time in sport climbers?

BACKGROUND: The ability to generate high levels of force with the finger flexor muscles and sustain it for the maximum time was reported as a climbing performance factor. This study aimed to answer the question of which is the most reliable edge depth to measure maximum hanging time in non-elite and elite rock climbers: 6, 8, 10, 12 or 14 mm. METHODS: Thirty-six climbers (10 female, 26 male; 6b-8c redpoint level) were assessed twice, one week apart. RESULTS: Systematic bias (95 % limits of agreements) was -1.84 (6.31) for HT6, -0.26 (8.83) for HT8, -1.30 (8.72) for HT10, -4.37 (9.57) for HT12, and -2.94 (9.53) for HT14 at non-elite group (all P values > 0.05 but HT12 and HT14). Among elite group, -1.38 (7.58), 0.68 (12.09), -2.20 (13.35), -0.49 (9.80) and 0.73 (10.44) was found (all P > 0.05) for HT6, HT8, HT10, HT12 and HT14, respectively. No patterns of heteroscedasticity were observed for any of the trials for non-elite and elite climbers. SIGNIFICANCE: Among all edge depths analysed, 8 mm seemed to be the most accurate edge to evaluate hanging time. Alternatively, a 10 mm hold depth could be recommended for climbers from 6b to 7c, and 12 mm for climbers from 7c+ to 8c.

Self-perceived knowledge level of epidemic management in medical residents prior to the start of the COVID-19 pandemic in Mexico.

INTRODUCTION: COVID-19 was declared a pandemic in March 2020, requiring a comprehensive response from all healthcare systems, including Mexico's. As medical residents' training did not involve epidemic response, we decided to evaluate their level of training on this subject, specifically self-perceived knowledge level and capacity to respond to epidemiological crises. METHODOLOGY: Medical residents from two hospitals belonging to PEMEX (Mexico's state-owned petroleum company) were included in a cross-sectional study. All participants answered a modified version of the survey developed by the University of Lovaina's Center for Research and Education in Emergency Care. Participants were analyzed according to their relevant "clinical" or "surgical" residency tracks. Data were analyzed using through Chi-square tests, t-tests, Mann-Whitney U tests, Kruskal-Wallis tests, and Pearson and Spearman correlation coefficients with significance established at p < 0.05. RESULTS: Of a total of 94 resident participants in this study, 56.7% self-perceived themselves as being poorly prepared to confront the pandemic. Only 25.5% of the participants referred previous experience in medical responses to public health emergencies, and only 35.1% reported ever receiving education on this topic. CONCLUSIONS: Medical residents-who have been involved with caring for victims of the pandemic-are under the general perception that they are not prepared, experienced, or educated enough to respond to such a widespread massive public health emergency.

Percepción del paciente ante el acto anestésico: desarrollo de una encuesta breve en español para medir satisfacción / Patient perception of the anesthetic act: development of a brief survey in Spanish to measure satisfaction

Resumen: Introducción: El desarrollo de encuestas representa un proceso complejo que requiere la verificación de su utilidad antes de su aplicación. A nivel internacional existen pocos instrumentos para medir la percepción de la atención anestésica en cirugías electivas, sin olvidar que, en su mayoría, se crearon en inglés; por lo que el propósito de este estudio fue desarrollar una encuesta breve sobre la atención anestésica como un indicador de calidad en la población mexicana. Material y métodos: Se trata de un estudio cualitativo que implica la fase de la construcción de una encuesta en la que se realizó una revisión de la literatura internacional y local de los instrumentos para medir satisfacción en anestesiología. Posteriormente, se realizaron entrevistas informales aleatorias a 82 pacientes sobre temas asociados al acto anestésico para la construcción de ítems. Resultados: La propuesta incluye 16 ítems divididos en tres secciones correspondientes a las tres valoraciones anestésicas básicas en una cirugía electiva y que exploran seis dominios: trato adecuado, comunicación, autonomía, atención oportuna, efectos secundarios y satisfacción. Conclusiones: La propuesta presentada es un potencial instrumento que podría reflejar la calidad percibida de la atención anestésica en nuestra población, por lo que, para fortalecer este proceso, se requerirá continuar con sus respectivas validaciones.

Abstract: Introduction: Survey development represents a complex process that requires verification of its usefulness before its application. At an international level, there are few instruments to measure the perception of anaesthetic care in elective surgeries, without forgetting that most of them were created in English; therefore, the purpose of this study was to develop a brief survey on anaesthetic care as an indicator of quality in the Mexican population. Material and methods: This is a qualitative study that involves the construction phase of a survey in which a review of the international and local literature of the instruments to measure satisfaction in anesthesiology was carried out. Subsequently, informal random interviews were conducted with 82 patients on the most sensitive issues associated with the anaesthetic act for the construction of items. Results: The proposal consists of 16 items divided into three sections corresponding to the three basic anaesthetic evaluations in elective surgery and that explore five domains: communication, autonomy, timely care, adequate treatment, and satisfaction. Conclusions: The proposal made in this project is a potential instrument that could reflect the perceived quality of anaesthetic care in our population, so to strengthen this process it will be necessary to continue with their respective validations.

COVID-19 epidemiology in a Mexican tertiary care hospital.

INTRODUCTION: As a result of COVID-19, many hospitals underwent a conversion for the care for this disease. OBJECTIVE: To analyze COVID-19 hospital epidemiological behavior from March to August 2020. METHODS: Through a series of cases, COVID-19 epidemiological behavior at the hospital was analyzed, for which simple case rates, percentages and incidence of COVID-19 per 100 hospital discharges were estimated. RESULTS: Out of 491 subjects who tested positive for SARS-CoV-2, 156 (31.7 %) were hospitalized for clinical data of moderate to severe disease. Average age was 59.1 years; 121 cases (75 %) were discharged due to improvement, and 32 (20.5 %), due to death. Average age of those who died was 69.7 years, and the most affected age group was 60 to 80 years (45.4 %). Calculated lethality was 20.5 per 100 hospital discharges, while that calculated taking into account positive patients (outpatients and hospitalized patients) was 6.5. CONCLUSIONS: COVID-19 epidemiological behavior was similar to that described in other studies; however, lethality and mortality are above national average. The analysis of this and of the factors that favored it in our population is pending.

INTRODUCCIÓN: A consecuencia de COVID-19, numerosos hospitales sufrieron una reconversión para la atención de esta enfermedad. OBJETIVO: Analizar el comportamiento epidemiológico hospitalario de COVID-19 entre marzo y agosto de 2020. MÉTODOS: En una serie de casos se analizó el comportamiento epidemiológico de COVID-19 en un hospital de tercer nivel, para lo cual se estimaron frecuencias simples de casos, porcentajes e incidencia por cada 100 egresos hospitalarios. RESULTADOS: De 491 sujetos con prueba positiva para SARS-CoV-2, 156 (31.7 %) fueron hospitalizados por datos clínicos de enfermedad moderada a grave. La edad promedio fue de 59.1 años; 121 casos (75 %) egresaron por mejoría y 32 (20.5 %), por defunción. El promedio de edad de quienes fallecieron fue de 69.7 años y el grupo etario más afectado fue el de 60 a 80 años (45.4 %). La letalidad calculada fue de 20.5 por 100 egresos hospitalarios, mientras que la calculada tomando en cuenta los pacientes positivos (ambulatorios y hospitalizados) fue de 6.5. CONCLUSIONES: El comportamiento epidemiológico de COVID-19 fue similar al descrito en otros estudios; sin embargo, la letalidad y la mortalidad están por encima de la media nacional. Está pendiente el análisis de estas y de los factores que las favorecieron en nuestra población.

Epidemiología de COVID-19 en un hospital de tercer nivel mexicano / COVID-19 epidemiology in a Mexican tertiary care hospital

Resumen Introducción: A consecuencia de COVID-19, numerosos hospitales sufrieron una reconversión para la atención de esta enfermedad. Objetivo: Analizar el comportamiento epidemiológico hospitalario de COVID-19 entre marzo y agosto de 2020. Métodos: En una serie de casos se analizó el comportamiento epidemiológico de COVID-19 en un hospital de tercer nivel, para lo cual se estimaron frecuencias simples de casos, porcentajes e incidencia por cada 100 egresos hospitalarios. Resultados: De 491 sujetos con prueba positiva para SARS-CoV-2, 156 (31.7 %) fueron hospitalizados por datos clínicos de enfermedad moderada a grave. La edad promedio fue de 59.1 años; 121 casos (75 %) egresaron por mejoría y 32 (20.5 %), por defunción. El promedio de edad de quienes fallecieron fue de 69.7 años y el grupo etario más afectado fue el de 60 a 80 años (45.4 %). La letalidad calculada fue de 20.5 por 100 egresos hospitalarios, mientras que la calculada tomando en cuenta los pacientes positivos (ambulatorios y hospitalizados) fue de 6.5. Conclusiones: El comportamiento epidemiológico de COVID-19 fue similar al descrito en otros estudios; sin embargo, la letalidad y la mortalidad están por encima de la media nacional. Está pendiente el análisis de estas y de los factores que las favorecieron en nuestra población.

Abstract Introduction: As a result of COVID-19, many hospitals underwent a conversion for the care for this disease Objective: To analyze COVID-19 hospital epidemiological behavior from March to August 2020. Methods: Through a series of cases, COVID-19 epidemiological behavior at the hospital was analyzed, for which simple case rates, percentages and incidence of COVID-19 per 100 hospital discharges were estimated. Results: Out of 491 subjects who tested positive for SARS-CoV-2, 156 (31.7 %) were hospitalized for clinical data of moderate to severe disease. Average age was 59.1 years; 121 cases (75 %) were discharged due to improvement, and 32 (20.5 %), due to death. Average age of those who died was 69.7 years, and the most affected age group was 60 to 80 years (45.4 %). Calculated lethality was 20.5 per 100 hospital discharges, while that calculated taking into account positive patients (outpatients and hospitalized patients) was 6.5. Conclusions: COVID-19 epidemiological behavior was similar to that described in other studies; however, lethality and mortality are above national average. The analysis of this and of the factors that favored it in our population is pending.

Prevalencia de diabetes mellitus en el ámbito de la atención primaria española y su asociación con factores de riesgo cardiovascular y enfermedades cardiovasculares. Estudio SIMETAP-DM / Prevalence of diabetes mellitus in Spanish primary care setting and its association with cardiovascular risk factors and cardiovascular diseases. SIMETAP-DM study

Introducción: Los objetivos del estudio fueron determinar las tasas de prevalencia brutas y ajustadas por edad y sexo de diabetes mellitus (DM), DM tipo 1 (DM1) y DM tipo 2 (DM2), y comparar la asociación de factores de riesgo cardiovascular, enfermedades cardiovasculares, enfermedad renal crónica y enfermedades metabólicas entre las poblaciones con y sin DM. Métodos: SIMETAP-DM es un estudio observacional transversal realizado en atención primaria, con una muestra aleatoria de base poblacional de 10.579 adultos. Tasa de respuesta: 66%. Los diagnósticos de DM, DM1 y DM2 se basaron en criterios clínicos y bioquímicos y/o en la comprobación de estos diagnósticos en las historias clínicas. Se determinaron las prevalencias brutas y ajustadas por edad y sexo (estandarizadas con la población española). Resultados: Las prevalencias brutas de DM1, DM2 y DM fueron del 0,87% (intervalo de confianza al 95% [IC 95%]: 0,67-1,13), el 14,7% (IC 95%: 13,9-15,6) y el 15,6% (IC 95%: 14,7-16,5), respectivamente. Las prevalencias ajustadas por edad y sexo de DM1, DM2 y DM fueron del 1,0% (1,3% para hombres y 0,7% para mujeres), el 11,5% (13,6% para hombres y 9,7% para mujeres) y el 12,5% (14,9% para hombres y 10,5% para mujeres), respectivamente. La prevalencia de DM en la población ≥ 70 años era el doble (30,3% [IC 95%: 28,0-32,7]) que en la población entre 40 y 69 años (15,3% [IC 95%: 14,1-16,5%]). La hipertensión arterial, la enfermedad arterial periférica, el índice cintura-talla aumentado, la albuminuria, la enfermedad coronaria, la dislipidemia aterogénica y la hipercolesterolemia se asociaban con la DM. Conclusiones: En el ámbito de la atención primaria española, las prevalencias ajustadas por edad de DM1, DM2 y DM en la población adulta fueron del 1,0, el 11,5 y el 12,5%, respectivamente. Un tercio de la población mayor de 70 años padecía DM

Introduction: The aims of this study were to determine the age- and sex-adjusted prevalence rates of DM, type-1 DM (T1DM), and type-2 DM (T2DM), and to compare the relationship with cardiovascular risk factors, cardiovascular diseases, chronic kidney disease, and metabolic diseases between populations with and without DM. Methods: SIMETAP-DM is a cross-sectional observational study conducted in a Primary Care setting with a random population-based sample of 10,579 adults. Response rate: 66%. The diagnoses of DM, T1DM and T2DM were based on clinical and biochemical criteria and/or the checking of these diagnoses in the medical records. The crude and age- and sex-adjusted (standardised for Spanish population) prevalence rates were calculated. Results: The crude prevalence rates of T1DM, T2DM, and DM were 0.87% (95% confidence interval [95% CI]: 0.67-1.13), 14.7% (95% CI: 13.9-15.6), and 15.6% (95% CI: 14.7-16.5), respectively. The age- and sex-adjusted prevalence rates of T1DM, T2DM, and DM were 1.0% (1.3% for men and 0.7% for women), 11.5% (13.6% for men and 9.7% for women), and 12.5% (14.9% for men and 10.5% for women), respectively. The prevalence of DM in the population ≥ 70 years was double (30.3% [95% CI: 28.0-32.7]) that of the population between 40 and 69 years (15.3% [95% CI: 14.1-16.5]). Hypertension, peripheral arterial disease, increased waist-to-height ratio, albuminuria, coronary heart disease, atherogenic dyslipidaemia and hypercholesterolaemia were associated with DM. Conclusions: In a Spanish primary care setting, the age-adjusted prevalences of T1DM, T2DM and DM in the adult population were 1.0, 11.5, and 12.5%, respectively. One-third (33%) of the population over 70 years had DM

Prevalence of diabetes mellitus in Spanish primary care setting and its association with cardiovascular risk factors and cardiovascular diseases. SIMETAP-DM study. / Prevalencia de diabetes mellitus en el ámbito de la atención primaria española y su asociación con factores de riesgo cardiovascular y enfermedades cardiovasculares. Estudio SIMETAP-DM.

INTRODUCTION: The aims of this study were to determine the age- and sex-adjusted prevalence rates of DM, type-1 DM (T1DM), and type-2 DM (T2DM), and to compare the relationship with cardiovascular risk factors, cardiovascular diseases, chronic kidney disease, and metabolic diseases between populations with and without DM. METHODS: SIMETAP-DM is a cross-sectional observational study conducted in a Primary Care setting with a random population-based sample of 10,579 adults. Response rate: 66%. The diagnoses of DM, T1DM and T2DM were based on clinical and biochemical criteria and/or the checking of these diagnoses in the medical records. The crude and age- and sex-adjusted (standardised for Spanish population) prevalence rates were calculated. RESULTS: The crude prevalence rates of T1DM, T2DM, and DM were 0.87% (95% confidence interval [95% CI]: 0.67-1.13), 14.7% (95% CI: 13.9-15.6), and 15.6% (95% CI: 14.7-16.5), respectively. The age- and sex-adjusted prevalence rates of T1DM, T2DM, and DM were 1.0% (1.3% for men and 0.7% for women), 11.5% (13.6% for men and 9.7% for women), and 12.5% (14.9% for men and 10.5% for women), respectively. The prevalence of DM in the population≥70 years was double (30.3% [95% CI: 28.0-32.7]) that of the population between 40 and 69 years (15.3% [95% CI: 14.1-16.5]). Hypertension, peripheral arterial disease, increased waist-to-height ratio, albuminuria, coronary heart disease, atherogenic dyslipidaemia and hypercholesterolaemia were associated with DM. CONCLUSIONS: In a Spanish primary care setting, the age-adjusted prevalences of T1DM, T2DM and DM in the adult population were 1.0, 11.5, and 12.5%, respectively. One-third (33%) of the population over 70 years had DM.

Comparison of the Effects of Three Hangboard Strength and Endurance Training Programs on Grip Endurance in Sport Climbers.

Intermittent isometric endurance of the forearm flexors is a determinant factor of sport climbing performance. However, little is known about the best method to improve grip endurance in sport climbing regarding maximal or intermittent dead-hang training methods. The aim of this study was to compare the effects of three 8-week finger training programs using dead-hangs (maximal, intermittent, and a combination) on grip endurance. Twenty-six advanced sport climbers (7c+/8a mean climbing ability) were randomly distributed among three groups: maximal dead-hangs with maximal added weight on an 18 mm edge followed by MaxHangs on minimal edge depth; intermittent dead-hangs using the minimal edge depth, and a combination of both. The grip endurance gains and effect size were 34% and 0.6, respectively, for the group following maximal dead-hang training, 45% and 1, respectively, for the group following intermittent dead-hang training, and 7% and 0.1, respectively, for the group applying the combination of both training methods. Grip endurance increased significantly after 4 weeks in the group performing intermittent dead-hangs (p = 0.004) and after 8 weeks in both groups performing intermittent dead-hangs (p = 0.002) and MaxHangs (p = 0.010). The results suggest that the intermittent dead-hangs training method seems to be more effective for grip endurance development after eight week application in advanced sport-climbers. However, both methods, maximal and intermittent dead-hangs, could be alternated for longer training periods.

Computational Modeling of Exciton-Bath Hamiltonians for Light Harvesting 2 and Light Harvesting 3 Complexes of Purple Photosynthetic Bacteria at Room Temperature.

Light harvesting 2 (LH2) complex is the primary component of the photosynthetic unit of purple bacteria that is responsible for harvesting and relaying excitons. The electronic absorption line shape of LH2 contains two major bands at 800 and 850 nm wavelength regions. Under low light conditions, some species of purple bacteria replace LH2 with light harvesting 3 (LH3), a variant form with almost the same structure as the former but with distinctively different spectral features. The major difference between the absorption line shapes of LH2 and LH3 is the shift of the 850 nm band of the former to a new 820 nm region. The microscopic origin of this difference has been the subject of some theoretical/computational investigations. However, the genuine molecular level source of such a difference is not clearly understood yet. This work reports a comprehensive computational study of LH2 and LH3 complexes so as to clarify different molecular level features of LH2 and LH3 complexes and to construct simple exciton-bath models with a common form. All-atomistic molecular dynamics simulations of both LH2 and LH3 complexes provide detailed molecular level structural differences of bacteriochlorophylls (BChls) in the two complexes, in particular, in their patterns of hydrogen bonding (HB) and torsional angles of the acetyl group. Time-dependent density functional theory calculation of the excitation energies of BChls for structures sampled from the MD simulations suggests that the observed differences in the HB and torsional angles cannot fully account for the experimentally observed spectral shift of LH3. Potential sources that can explain the actual spectral shift of LH3 are discussed, and their magnitudes are assessed through fitting of experimental line shapes. These results demonstrate the feasibility of developing simple exciton-bath models for both LH2 and LH3, which can be employed for large-scale exciton quantum dynamics in their aggregates.

Neoplasia vulvar intraepitelial / Vulvar intraepithelial neoplasia

Objetivo: realizar una revisión de la literatura a propósito de un caso de neoplasia vulvar intraepitelial de alto grado tratada con imiquimod tópico. Conclusión: el tratamiento tópico con imiquimod constituye una alternativa al tratamiento quirúrgico de la neoplasia vulvar intraepitelial. En el caso que se presenta se logró la completa desaparición de la lesiones tras doce semanas de tratamiento. Existen otros tratamientos tópicos que pueden ser tenidos en cuenta, como el 5-fluoracilo o cidofovir. Dada la posibilidad de recurrencias, se debe realizar un seguimiento estrecho de estas pacientes durante al menos cinco años (AU)

Objective: To review the literature and present a clinical case of vulvar intraepithelial neoplasia that was treated with topical Imiquimod. Conclusion: Topical treatment with Imiquimod is an alternative to surgical treatment of vulvar intraepithelial neoplasia. In the case presented, complete disappearance of the lesions was achieved after twelve weeks of treatment. There are other treatments that can be taken into account, such as 5-fluoracil and cidofovir. Given the possibility of recurrence, these patients should be closely followed during at least five years (AU)

A new nucleocytoplasmic RhoGAP protein contributes to control the pathogenicity of Entamoeba histolytica by regulating EhRacC and EhRacD activity.

Small GTPases are signalling molecules that regulate important cellular processes. GTPases are deactivated by GTPase-activating proteins (GAPs). While human GAPs have been intensively studied, no GAP has yet been characterized in Entamoeba histolytica. In this study, we identified and characterized a novel nucleocytoplasmic RhoGAP in E. histolytica termed EhRhoGAPnc. In silico analyses of the domain structure revealed a previously undescribed peptide region within the carboxy-terminal region of EhRhoGAPnc capable of interacting with phosphatidic acid and phosphatidylinositol 3,5-bisphosphate. The full structural GAP domain showed increase GAP activity compared with the minimum region able to display GAP activity, as analysed both by experimental assays and molecular dynamics simulations. Furthermore, we identified amino acid residues that promote interactions between EhRhoGAPnc and its target GTPases EhRacC and EhRacD. Immunofluorescence studies revealed that EhRhoGAPnc colocalized with EhRacC and EhRacD during uroid formation but not during erythrophagocytosis. Interestingly, during erythrophagocytosis of red blood cells, EhRhoGAPnc colocalized with phosphatidic acid and phosphatidylinositol 3,5-bisphosphate. Overexpression of EhRhoGAPnc in E. histolytica led to inhibition of actin adhesion plate formation, migration, adhesion of E. histolytica to MDCK cells and consequently to an impairment of the cytopathic activity.

Identification of repressive and active epigenetic marks and nuclear bodies in Entamoeba histolytica.

BACKGROUND: In human hosts, Entamoeba histolytica cysts can develop into trophozoites, suggesting that the life cycle of this parasite are regulated by changes in gene expression. To date, some evidence has suggested that epigenetic mechanisms such as DNA methylation and histone modification are involved in the regulation of gene expression in Entamoeba. Some post-translational modifications (PTMs) at the N-terminus of E. histolytica's histones have been reported experimentally, including tri-methylation in the lysine 4 of histone H3 (H3K4me3) and dimethylation in the lysine 27 of histone H3 (H3K27me2), dimethylation of arginine 3 (H4R3me2) and the indirect acetylation of histone H4 in the N-terminal region. However, it is not known which residues of histone H4 are subject to acetylation and/or methylation or where in the nucleus these epigenetic marks are located. METHODS: Histones from trophozoites of E. histolytica were obtained and analyzed by LC-MS/MS. WB assays were performed using antibodies against epigenetic marks (acetylated lysines and methylated arginines). Immunofluorescence assays (IFA) were carried out to determine the distribution of PTMs and the localization of DNA methylation as a heterochromatin marker. Nuclear bodies such as the nucleolus were identified by using antibodies against fibrillarin and nucleolin and speckles by using anti-PRP6 antibody. RESULTS: Some new PTMs in histone H4 of E. histolytica, such as the acetylation of lysines 5, 8, 12 and 16 and the monomethylation of arginine 3, were identified by WB. IFA demonstrated that some marks are associated with transcriptional activity (such as acetylation and/or methylation) and that these marks are distributed throughout the E. histolytica nucleus. Staining with antibodies against anti-pan-acetylated lysine H4 histone and 5-methyl cytosine showed that the activation and transcriptional repression marks converge. Additionally, two nuclear bodies, the nucleolus and speckles, were identified in this parasite. CONCLUSIONS: This study provides the first evidence that the nucleus of E. histolytica is not compartmentalized and contains two nuclear bodies, the nucleolus and speckles, the latter of which was not identified previously. The challenge is now to understand how these epigenetic marks and nuclear bodies work together to regulate gene expression in E. histolytica.

Gestación gemelar monocigótica asociada a técnicas de reproducción asistida / Monozigotic twinning associated with assisted reproductive technologies

La frecuencia de gestaciones gemelares monocigóticas se estima entre 0,4-0,45% de las gestaciones espontáneas. Sin embargo, tras la utilización de técnicas de reproducción asistida (TRA) numerosos estudios han demostrado un aumento del riesgo de gestaciones monocigóticas. A propósito de 2 casos presentados recientemente en nuestro servicio, planteamos una revisión de los posibles factores que se pueden asociar entre las TRA y la gestación múltiple monocigótica (AU)

Monozygotic twin pregnancies account for about 0.4%-0.45% of nonstimulated in vivo conceptions. However, numerous studies have demonstrated that the risk of these pregnancies is increased after the use of assisted reproductive technologies. We report two cases of monozygotic twin pregnancies that occurred recently in our hospital and review the possible factors that may be involved in the association between assisted reproductive technologies and monozygotic twin pregnancies (AU)

Molecular Level Design Principle behind Optimal Sizes of Photosynthetic LH2 Complex: Taming Disorder through Cooperation of Hydrogen Bonding and Quantum Delocalization.

The light harvesting 2 (LH2) antenna complex from purple photosynthetic bacteria is an efficient natural excitation energy carrier with well-known symmetric structure, but the molecular level design principle governing its structure-function relationship is unknown. Our all-atomistic simulations of nonnatural analogues of LH2 as well as those of a natural LH2 suggest that nonnatural sizes of LH2-like complexes could be built. However, stable and consistent hydrogen bonding (HB) between bacteriochlorophyll and the protein is shown to be possible only near naturally occurring sizes, leading to significantly smaller disorder than for nonnatural ones. Extensive quantum calculations of intercomplex exciton transfer dynamics, sampled for a large set of disorder, reveal that taming the negative effect of disorder through a reliable HB as well as quantum delocalization of the exciton is a critical mechanism that makes LH2 highly functional, which also explains why the natural sizes of LH2 are indeed optimal.

Exploring the role of hydration and confinement in the aggregation of amyloidogenic peptides Aß(16-22) and Sup35(7-13) in AOT reverse micelles.

Knowledge of how intermolecular interactions of amyloid-forming proteins cause protein aggregation and how those interactions are affected by sequence and solution conditions is essential to our understanding of the onset of many degenerative diseases. Of particular interest is the aggregation of the amyloid-ß (Aß) peptide, linked to Alzheimer's disease, and the aggregation of the Sup35 yeast prion peptide, which resembles the mammalian prion protein linked to spongiform encephalopathies. To facilitate the study of these important peptides, experimentalists have identified small peptide congeners of the full-length proteins that exhibit amyloidogenic behavior, including the KLVFFAE sub-sequence, Aß16-22, and the GNNQQNY subsequence, Sup357-13. In this study, molecular dynamics simulations were used to examine these peptide fragments encapsulated in reverse micelles (RMs) in order to identify the fundamental principles that govern how sequence and solution environment influence peptide aggregation. Aß16-22 and Sup357-13 are observed to organize into anti-parallel and parallel ß-sheet arrangements. Confinement in the sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles is shown to stabilize extended peptide conformations and enhance peptide aggregation. Substantial fluctuations in the reverse micelle shape are observed, in agreement with earlier studies. Shape fluctuations are found to facilitate peptide solvation through interactions between the peptide and AOT surfactant, including direct interaction between non-polar peptide residues and the aliphatic surfactant tails. Computed amide I IR spectra are compared with experimental spectra and found to reflect changes in the peptide structures induced by confinement in the RM environment. Furthermore, examination of the rotational anisotropy decay of water in the RM demonstrates that the water dynamics are sensitive to the presence of peptide as well as the peptide sequence. Overall, our results demonstrate that the RM is a complex confining environment where substantial direct interaction between the surfactant and peptides plays an important role in determining the resulting ensemble of peptide conformations. By extension the results suggest that similarly complex sequence-dependent interactions may determine conformational ensembles of amyloid-forming peptides in a cellular environment.

Bioaccumulations of heavy metals in Ipomoea aquatica grown in bottom ash recycling wastewater.

A plant bioassay using hydroponically grown Ipomoea aquatica (water spinach) was applied to assess the phytotoxicity of untreated and treated wastewaters from a municipal solid waste incineration bottom ash recycling facility. The 50%-diluted, untreated wastewater exhibited acute toxicity (plants died within 24 hours). Highly diluted doses (3 and 6%) of both wastewater types displayed no significant differences when compared with the control. Treating the wastewater through sequential physical filtration and chemical precipitation processes decreased not only the dissolved solids content but also the pH and salt content. In addition, significant accumulations of Sr, Cr, and Sn were observed in the hydroponically grown I. aquatica plant tissues; in particular, the bioaccumulation of Sr in the leaves and roots was unexpectedly high.

Influence of site-dependent pigment-protein interactions on excitation energy transfer in photosynthetic light harvesting.

A site-dependent spectral density system-bath model of the Fenna-Matthews-Olsen (FMO) pigment-protein complex is developed using results from ground-state molecular mechanics simulations together with a partial charge difference model for how the long-range contributions to the chromophore excitation energies fluctuate with environmental configuration. A discussion of how best to consistently process the chromophore excitation energy fluctuation correlation functions calculated in these classical simulations to obtain reliable site-dependent spectral densities is presented. The calculations reveal that chromophores that are close to the protein-water interface can experience strongly dissipative environmental interactions characterized by reorganization energies that can be as much as 2-3 times those of chromophores that are buried deep in the hydrophobic protein scaffolding. Using a linearized density matrix quantum propagation method, we demonstrate that the inhomogeneous system-bath model obtained from our site-dependent spectral density calculations gives results consistent with experimental dissipation and dephasing rates. Moreover, we show that this model can simultaneously enhance the energy-transfer rate and extend the decoherence time. Finally, we explore the influence of initially exciting different chromophores and mutating local environments on energy transfer through the network. These studies suggest that different pathways, selected by varying initial photoexcitation, can exhibit significantly different relaxation times depending on whether the energy-transfer path involves chromophores at the protein-solvent interface or if all chromophores in the pathway are buried in the protein.

Disgenesia gonadal parcial XY. Diagnóstico en edad adulta / 46 XY partial gonadal dysgenesis. Diagnosis in adulthood

Se presenta el caso de una persona adulta de 24 años con genitales externos ambiguos, nunca estudiada ni tratada y que se había etiquetado de hermafroditismo en su país de origen. Estos casos son evaluados en su mayoría al nacimiento, siendo el diagnóstico más frecuente el de hiperplasia suprarrenal congénita y uno de los más infrecuentes el de la disgenesia gonadal parcial 46XY que presentamos (AU)

We report the case of a 24-year-old adult with ambiguous external genitalia, who had never been studied or treated, but who was labelled as a hermaphrodite in the country of origin. These cases are usually evaluated at birth, the most frequent diagnosis being congenital adrenal hyperplasia. We present a case of one of the least common of these disorders, 46XY partial gonadal dysgenesis (AU)

Protein folding in a reverse micelle environment: the role of confinement and dehydration.

Characterization of the molecular interactions that stabilize the folded state of proteins including hydrogen bond formation, solvation, molecular crowding, and interaction with membrane environments is a fundamental goal of theoretical biophysics. Inspired by recent experimental studies by Gai and co-workers, we have used molecular dynamics simulations to explore the structure and dynamics of the alanine-rich AKA(2) peptide in bulk solution and in a reverse micelle environment. The simulated structure of the reverse micelle shows substantial deviations from a spherical geometry. The AKA(2) peptide is observed to (1) remain in a helical conformation within a spherically constrained reverse micelle and (2) partially unfold when simulated in an unconstrained reverse micelle environment, in agreement with experiment. While aqueous solvation is found to stabilize the N- and C-termini random coil portions of the peptide, the helical core region is stabilized by significant interaction between the nonpolar surface of the helix and the aliphatic chains of the AOT surfactant. The results suggest an important role for nonpolar peptide-surfactant and peptide-lipid interactions in stabilizing helical geometries of peptides in reverse micelle environments.