Abstract The municipality of Nuevo Ideal is one of the most important regions for apple production in the state of Durango, Mexico. There are scattered Malus domestica trees from extinct orchards that were part of a production system and that today are abandoned without agronomic management, but that have shown an efficient adaptability to the conditions and continue to produce good quality fruit. The objective of this study was to develop an in vitro propagation protocol of M. domestica using seeds of feral trees from this region. Germination and production of adventitious shoots were evaluated using Murashige & Skoog (MS) medium and woody plant medium (WPM) supplemented with phytohormones 6-Benzylaminopurine (BAP) and indole butyric acid (IBA) at different doses. For rooting, indole acetic acid (IAA), naphthaleneacetic acid (NAA) and kinetin (KIN) were also used in combination with the previous ones. Germination and shoot formation obtained better results with the concentration of 0.5 mg L-1 of BAP in MS medium at 60 days. In the leaf development, the treatment with 1.5 mg L-1 of BAP in MS medium stood out, with 21.07 leaves on average. The plants of all the treatments had roots, however, the best development was shown by the treatment with 1.5 mg L-1 of NAA and 0.15 mg L-1 of BAP in WPM medium. Through the protocol generated in this research, it is possible to massively propagate the M. domestica species for purposes of germplasm conservation and subsequent exploitation of the crop.

Resumen El municipio de Nuevo Ideal es una de las regiones más importantes para la producción de manzana en el estado de Durango, México. Existen árboles dispersos de Malus domestica de huertos extintos que fueron parte de un sistema de producción y que hoy están abandonados sin manejo agronómico, pero que han mostrado una adaptabilidad eficiente a las condiciones y continúan produciendo fruto de buena calidad. El objetivo del presente estudio fue desarrollar un protocolo de propagación in vitro de M. domestica utilizando semillas de árboles asilvestrados de esta región. Se evaluó la germinación y producción de brotes adventicios usando medios de cultivo murashige & skoog (MS) y woody plant medium (WPM) complementados con fitohormonas 6-Bencilaminopurina (BAP) y ácido indol butírico (IBA) en diferentes dosis. Para el enraizamiento se utilizó también ácido indol acético (AIA), ácido naftalenacético (ANA) y kinetina (KIN) en combinación con las anteriores. La germinación y formación de brotes obtuvo mejor resultado con la concentración de 0.5 mg L-1 de BAP en el medio MS a los 60 días. En el desarrollo foliar destacó el tratamiento con 1.5 mg L-1 BAP en medio MS con 21.07 hojas en promedio. Las plantas de todos los tratamientos presentaron raíz, sin embargo, el mejor desarrollo lo presentó el tratamiento con 1.5 mg L-1 de ANA y 0.15 mg L-1 de BAP en medio WPM. Mediante el protocolo generado en esta investigación, es posible propagar masivamente la especie M. domestica con propósitos de conservación de germoplasma y posterior explotación del cultivo.

Resumen El propósito de este estudio fue la cuantificación de Esfingosina-1-Fosfato (S1P) en las bolsas periodontales de pacientes con periodontitis. Estudio observacional, descriptivo de casos y controles. 30 sujetos fueron seleccionados de los cuales 15 controles y 15 casos. Se realizó un estudio periodontal completo siguiendo los parámetros establecidos por la AAP en 2017 para el diagnóstico de las enfermedades periodontales. Se tomaron muestras de saliva y de líquido crevicular gingival de cada sujeto estudiado y se analizaron con el ELISA kit humano para S1P (MyBiosource #MBS2516132) y de acuerdo con las instrucciones del fabricante, se realizó para cuantificar la presencia d S1P en las muestras estudiadas. Los resultados mostraron diferencia significativa (p=0.05) entre casos y controles. En el caso de las muestras de saliva, la concentración de S1P en controles fue mayor (72.94 ng/mL y 45.12 ng/mL). Para Líquido crevicular gingival, se encontró mayor cantidad de S1P en los pacientes con periodontitis (20.09 ng/mL y 15.20 ng/mL). Este estudio plantea una posible ruta de metabolismo óseo, proceso inflamatorio e identificación de la Periodontitis a través de la cuantificación oral de S1P, sin embargo se necesitan estudios futuros.

Abstract The aim of this study was the quantification of Sphingosine-1-phosphate (S1P) in periodontal pockets of patients with periodontitis. This is an observational, descriptive, case-control study. Thirty subjects were selected: 15 controls and 15 cases. A periodontal study was conducted following the parameters of AAP 2017 for the diagnosis of periodontal diseases. A sample of saliva and gingival crevicular fluid was obtained from each subject and then analyzed with the Human S1P Elisa kit (MyBioSource #MBS2516132) accordingly to the manufacturer's instructions, in order to verify the presence of S1P and quantify it´s concentration when founded. Results showed a significant difference (p=0.05) between cases and controls. In the case of saliva samples, the concentration of S1P was higher than the ones found in the control group (72.94 ng/mL and 45.12 ng/mL). For GCF, a higher amount of S1P was found in patients with POD (20.09 ng/mL and 15.20 ng/mL). This work raises a possible route of bone metabolism, inflammatory process, and identification of periodontitis through oral quantification of S1P, however, future studies are needed.

Abstract Helietta parvifolia is a species of economic importance in Northern Mexico, being a potential source of wood and firewood for several uses. The objective of the study was to evaluate the structure and diversity of a mature H. parvifolia scrub in Northwest Mexico. Vegetation diversity was determined by establishing 20 sampling sites of 10 × 10 m each (2000 m² in total), where the normal and crown diameter of all trees and shrubs with a diameter ≥ 3 cm were recorded. The Margalef, Shannon and Pretzsch indexes were calculated for richness, species diversity and vertical structure, respectively. Eleven tree and shrub species were found, distributed in nine genera and six families. The Fabaceae family had the highest number of taxa (five), while the remaining families had only one species. Three of them concentrated 82.59 % of the importance value index values (IVI): Helietta parvifolia, Cordia boissieri and Havardia pallens, with 53 %, 15.44 % and 14.15%, respectively. The abundance of individuals of small diameter classes suggests the existence of an active regeneration state.

Resumen Helietta parvifolia es una especie de importancia económica en el norte de México, ya que es una fuente potencial de madera y leña para usos diversos. El objetivo del presente estudio fue evaluar la estructura y diversidad de un matorral maduro de H. parvifolia en el noroeste de México. Se determinó la diversidad de la vegetación mediante el establecimiento de 20 sitios de muestreo de 10 × 10 m cada uno (2 000 m² en total), en donde se registraron las especies, el diámetro normal y de copa de todos los árboles y arbustos con un diámetro ≥ 3 cm. Se calcularon los índices de Margalef, Shannon y Pretzsch para determinar la riqueza, diversidad de especies y estructura vertical, respectivamente. Se registraron 11 especies arbóreas y arbustivas, distribuidas en nueve géneros y seis familias. Fabaceae fue la que registró un mayor número de taxones (cinco); mientras que las familias restantes presentaron solamente un taxón. Tres especies concentraron 82.59 % de los valores de índice de valor de importancia (IVI): Helietta parvifolia, Cordia boissieri y Havardia pallens, con 53 %, 15.44 % y 14.15 %, respectivamente. La mayor abundancia de individuos de clases diamétricas pequeñas sugiere la existencia de un estado de regeneración activo.

Abstract We report documented records of the Marañón crescentchest (Melanopareia maranonica) in six localities. These have hydrological connectivity with the middle basin of the Marañón River, in the provinces of Celendín (Cajamarca) and Luya (Amazonas), Peru. The records were obtained through occasional encounters, biological evaluations and intensive searching, between 2017 and 2020. These new records are between 1111 and 2074 m in elevation, exceeding its known altitudinal range by more than 1000 m. A total of 39 individuals were registered (11 females, 12 males and 16 indeterminate due to the fact that only auditory registration was made). We expanded the known range with respect to the published records by 121 km in the Cajamarca department and 98.2 km in the Amazonas department. Appropriate habitat for this species is protected in 5290.12 ha of the Marañón Seasonally Dry Inter-Andean Forest ecosystem and 7784.67 ha of Andean Scrub, within three Private Conservation Areas and one Regional Conservation Area.

Resumen Reportamos registros documentados de la ampliación del rango de distribución del pecho de luna del Marañón (Melanopareia maranonica) en seis localidades. Estas tienen conectividad hidrológica con la cuenca media del río Marañón, en las provincias de Celendín (Cajamarca) y Luya (Amazonas), Perú. Los registros fueron obtenidos mediante encuentros ocasionales, evaluaciones biológicas y búsqueda intensiva, entre el 2017 y 2020. Los nuevos registros están entre los 1111 y 2074 m, superando en más de 1000 m su rango altitudinal conocido. Se registraron un total de 39 individuos (11 hembras, 12 machos y 16 indeterminados debido a que solo se hizo registro auditivo). Respecto a los registros publicados, el rango conocido se amplía en 121 km en el departamento de Cajamarca y 98.2 km en el departamento de Amazonas. Se protege hábitat apropiado para la especie en 5290.12 ha del ecosistema Bosque Estacionalmente Seco Interandino del Marañón y 7784.67 ha de Matorral Andino, en tres Áreas de Conservación Privada y un Área de Conservación Regional.

Abstract Background: Ecological restoration is a process that helps the recovery of an ecosystem that has been degraded, damaged or destroyed. The success of restoration actions depend on the understanding of the processes, mechanisms and factors that guide vegetation dynamics. The restoration of plant communities can be made by unassisted (passive restoration, where the community recover by itself ) and assisted (active restoration) ecological succession. It is imperative to know the scope of both types of activities to guide future restoration actions by evaluating the properties and functioning of the intervened communities. Methods: Variance analysis of the carbon (C) stocks, basal area, canopy area, Shannon–Weaver index values, specific richness and abundance of three Tamaulipan thornscrub communities (assisted natural succession area, unassisted natural succession area and control area) was performed. Furthermore, a similarity analysis between the sampling areas using the floristic composition (abundance) was performed. Results: In total, 11 families, 17 genera and 20 species of vascular plants were registered. The richness of species and abundance ranked as follows per area: assisted ecological natural succession > control > unassisted ecological natural succession. The species composition between sampling areas showed a low number of common species between plant communities. Conclusions: The values of species richness, diversity, abundance, basal area, and canopy area of the assisted natural succession vegetal community was statistical similar to the control plan community. The values of C stocks showed that assisted ecological succession could recover not only structure and composition attributes but also this key ecosystem property.

Resumen Objetivo: La dispersión transmural de la repolarización ventricular (DTMRV) es un factor de riesgo para muerte en pacientes con síndrome isquémico coronario agudo (SICA). Con el objetivo de conocer el efecto de la realización de angioplastia sobre la DTMRV, se estudió la relación Tp-f/QTc en pacientes con SICA sometidos a angioplastia. Método: Se diseñó un estudio observacional, retrospectivo y descriptivo. Se incluyeron 150 pacientes (N = 150) con diagnóstico de SICA. Se valoró la relación Tp-f/QTc inicial y se evaluó su acortamiento posangioplastia. Como objetivo secundario, se comparó la asociación de dichos cambios en la relación Tp-f/QTc con la mortalidad cardiovascular y los eventos adversos cardiovasculares. Resultados: El promedio en la relación Tp-f/QTc inicial fue de 0.2529, mientras que posangioplastia fue de 0.2397. Por medio de prueba de rangos de Wilcoxon se evidenció un descenso significativo en la relación Tp-f/QTc posterior a la angioplastia, con un valor Z de −2.051 y una p < 0.04. En el análisis secundario se encontró que una Tp-f/QTc ≥ 0.29 posangioplastia es factor de riesgo para presentación de los siguientes eventos adversos: muerte intrahospitalaria (7.4 vs 0%; p < 0.003), nuevo SICA en seguimiento a 1 año (25.9 vs. 18.5%; p < 0.006) y reintervención en seguimiento a 1 año (29.6 vs. 15.0%; p < 0.002). Conclusiones: Existe un acortamiento significativo en la relación Tp-f/QTc posangioplastia en pacientes con SICA. Esta medida de la DTMRV puede servir como un predictor de muerte intrahospitalaria, eventos cardiovasculares y reintervención a 1 año en pacientes con SICA tratados con angioplastia.

Abstract Objective: Transmural Dispersion of Repolarization (TDR) is a Risk factor for Death in patients with Acute Coronary Syndrome (ACS). In order to know the effect of angioplasty on TDR, the Tp-e/QTc ratio was studied in patients with ACS undergoing angioplasty. Method: An observational, retrospective and descriptive study was designed. 150 patients (N = 150) with diagnosis of ACS were included. The initial Tp-e/QTc ratio was assessed and then its post-angioplasty shortening was evaluated. As a secondary objective, we compared the association of these Tp-e/QTc ratio changes with cardiovascular mortality and cardiovascular adverse events. Results: The average in the initial Tp-e/QTc ratio was 0.2529, while post-angioplasty was 0.2397. Through a Wilcoxon rage test, a significant decrease in the Tp-e/QTc ratio after angioplasty was observed, with a Z value of −2.051 and p < 0.04. In the secondary analysis, it was found that a Tp-e/QTc ≥ 0.29 post-angioplasty is a risk factor for presenting the following adverse events: in-hospital death (7.4 vs. 0%; p < 0.003), new ACS in 1-year follow-up (25.9 vs. 18.5%; p < 0.006), and reintervention in 1-year follow up (29.6 vs. 15%; p < 0.002). Conclusions: There is a significant shortening in the Tp-e/QTc ratio post-angioplasty in patients with ACS. This measure of TDR can serve as a predictor of in-hospital death, cardiovascular events and 1-year reintervention in patients with ACS treated initially by angioplasty.

Abstract Background: Cloning techniques are applied to an endangered orchid species in order to reproduce individual plants and to preserve their genetic characteristics. Objectives: To establish a new protocol for clonal propagation of a threatened orchid of horticultural importance. Study species: Trichocentrum stramineum, a threatened orchid endemic to Mexico. Study site and duration: Totutla, Veracruz, Mexico. All experiments were designed and carried out at the Botanical Garden-UNAM and the IIAF-UMSNH over a course of six years. Methods: Seeds were germinated in a modified KC basal medium; protocorms and apical bud explants were obtained from the resulting in vitro plants and cultivated with or without plant growth regulators (PGRs). Both experimental groups were subcultured in order to evaluate the number of protocorm-like bodies (PLBs) and buds per explant. Results: On average, protocorms generated 51.2 and 54.1 PLBs in the absence or presence of 1 mg l-1 6-benzyladenine (BA), respectively, while 13.1 and up to 23.7 PLBs and / or shoots were observed on the apical bud explants in the absence or presence of 1 mg l-1 kinetin, respectively. In both cases, responses were direct, without the formation of an intervening callus. Approximately 200 PLBs were subcultured and developed into whole plants within 14 weeks. These were acclimatized to greenhouse conditions with a 90 % survival rate after 12 weeks. After 44 weeks, flowering was observed (3 %) individuals measuring at least 12 cm in height. Conclusions: The developed protocol proved to hold great potential for commercial propagation and conservation programs.

Resumen Antecedentes: Las técnicas de clonación se utilizan para reproducir orquídeas en peligro de extinción, manteniendo las características genéticas de cada individuo a conservar. Objetivos: Establecer un nuevo protocolo para la propagación clonal de una planta con importancia hortícola. Especie de estudio: Trichocentrum stramineum, orquídea endémica y amenazada de México Sitio y años de estudio: Totutla, Veracruz. El estudio duró 6 años, desarrollado en el Jardín Botánico UNAM y el IIAF, UMSNH. Métodos: Las semillas germinaron en un medio basal KC modificado; se tomaron los protocormos y explantes de yemas apicales de las plantas in vitro resultantes y se cultivaron con o sin reguladores del crecimiento vegetal (PGR). Ambos se subcultivaron, evaluando el número de cuerpos similares a protocormos (PLB) y brotes unidos a cada explante. Resultados: Los protocormos generaron en promedio 51.2 y 54.1 PLB en ausencia o presencia de 1 mg l-1 benciladenina respectivamente, mientras que se observaron 13.1 y hasta 23.7 PLB y / o brotes en los explantes de yema apical en ausencia o presencia de 1 mg l-1 de cinetina, en ese orden, ambas respuestas fueron directas sin presencia de callo. Aproximadamente 200 PLBs fueron subcultivados y desarrollados en plantas enteras en 14 semanas. Estas se aclimataron a condiciones de invernadero con una tasa de supervivencia del 90 % después de 12 semanas. Después de 44 semanas, se observó floración (3 %) individuos que medían al menos 12 cm de altura. Conclusiones: El protocolo desarrollado demuestra su potencial en programas comerciales de propagación y conservación.

Abstract Antimicrobial resistance is one of the greatest challenges of modern medicine. During the last decade, a group of six bacteria have proven not only their ability to relatively “escape” the effects of almost any antimicrobial but also because they are the main cause of hospital infections. These organisms together are known as ESKAPE, acronyms derived from the first letter of the genus taxonomic from the scientific name of each bacteria ( Enterococcus spp, Staphylococcus aureus , Klebsiella pneumoniae, Acinetobacter baumannii , Pseudomonas aeruginosa y Enterobacter spp.). This review aims to describe the main resistance mechanisms associated with this group of bacteria and the impact they have had on the development of new antimicrobial strategies.

Resumen La resistencia a los antimicrobianos es uno de los más grandes retos de la medicina moderna. Durante la última década, un grupo de seis bacterias han probado no sólo su capacidad para relativamente “escapar” de los efectos de casi cualquier antimicrobiano, sino también por ser la causa principal de las infecciones hospitalarias. Estos organismos en conjunto se les conoce como ESKAPE, siglas que derivan de la primera letra de la categoría taxonómica género, o sea, del nombre científico de cada una de estas bacterias ( Enterococcus spp, Staphylococcus aureus , Klebsiella pneumoniae, Acinetobacter baumannii , Pseudomonas aeruginosa y Enterobacter spp.). La presente revisión tiene como objetivo describir los principales mecanismos de resistencia asociados a este grupo de bacterias y el impacto que han tenido en el desarrollo de nuevas estrategias antimicrobianas.

ABSTRACT OBJECTIVE To evaluate the effectiveness of adherence to a multidisciplinary renal health program in reducing mortality and progression to hemodialysis. METHODS We used a database that included patient monitoring (2013-2017), dialysis admissions and all cause of mortality in Peru. Adherence to the program was established by meeting minimum visits during the first year of monitoring. The outcome of interest was hemodialysis admissions or all cause-mortality. Kaplan-Meier curves, Log-Rank test and competing survival analysis methods were used to estimate the differential risk between adherent and non-adherent patients. RESULTS A total of 20,354 participants was evaluated; 54.1% were male, 72.1 years old in average, 2.2 years average follow-up, and 15,279 (75.1%) belonged to the early stages (1 to 3a) of Chronic Kidney Disease. Adherence decreased the risk of renal replacement therapy in 41.0% (HR = 0.59, 95%CI 0.41–0.85) in the low-risk group and mortality in the high-risk group was 31.0% (HR = 0.69, 95%CI 0.57–0.83). CONCLUSIONS The multidisciplinary care strategy with standardized assessments by stage is effective in reducing admission to .0when the patient is identified in early stages and in reducing mortality in advanced stages.

RESUMEN OBJETIVO Evaluar la efectividad de la adherencia a un programa de salud renal en la reducción de mortalidad y progresión a hemodiálisis. MÉTODOS Utilizamos una base de datos que condensaba el seguimiento de los pacientes (2013-2017), los ingresos a diálisis de los mismos y la mortalidad por todas las causas en Perú. La adherencia al programa se estableció con el cumplimiento de visitas mínimas durante su primer año de seguimiento. La efectividad de la adherencia al programa se midió en términos de debut a hemodiálisis o muerte por todas las causas. Se utilizaron curvas de Kaplan-Meier, test de diferencias en la distribución (Log-Rank test) y métodos de análisis de supervivencia. Los análisis se realizaron utilizando R estudio 3.5.0 RESULTADOS Fueron evaluados 20.354 participantes, 54,1% varones, edad media de 72,1 años, con un seguimiento medio de 2,2 años; 15.279 (75.1%) tuvieron ERC en estadios tempranos (estadio 1 al 3a). La adherencia disminuyó en un 41,0% el riesgo de terapia de reemplazo renal (HR = 0,59; IC95% 0,41–0,85) en el grupo de bajo riesgo y en un 31,0% (HR = 0,69; IC95% 0,57–0,83) la mortalidad en el grupo de alto riesgo. CONCLUSIONES La estrategia de cuidado multidisciplinario con evaluaciones estandarizadas según estadio es efectiva en reducir el ingreso a terapia de reemplazo renal cuando se identifica al paciente en estadios tempranos y en reducir la mortalidad en estadios avanzados.

ABSTRACT OBJECTIVE To evaluate the effectiveness of adherence to a multidisciplinary renal health program in reducing mortality and progression to hemodialysis. METHODS We used a database that included patient monitoring (2013-2017), dialysis admissions and all cause of mortality in Peru. Adherence to the program was established by meeting minimum visits during the first year of monitoring. The outcome of interest was hemodialysis admissions or all cause-mortality. Kaplan-Meier curves, Log-Rank test and competing survival analysis methods were used to estimate the differential risk between adherent and non-adherent patients. RESULTS A total of 20,354 participants was evaluated; 54.1% were male, 72.1 years old in average, 2.2 years average follow-up, and 15,279 (75.1%) belonged to the early stages (1 to 3a) of Chronic Kidney Disease. Adherence decreased the risk of renal replacement therapy in 41.0% (HR = 0.59, 95%CI 0.41–0.85) in the low-risk group and mortality in the high-risk group was 31.0% (HR = 0.69, 95%CI 0.57–0.83). CONCLUSIONS The multidisciplinary care strategy with standardized assessments by stage is effective in reducing admission to .0when the patient is identified in early stages and in reducing mortality in advanced stages.

RESUMEN OBJETIVO Evaluar la efectividad de la adherencia a un programa de salud renal en la reducción de mortalidad y progresión a hemodiálisis. MÉTODOS Utilizamos una base de datos que condensaba el seguimiento de los pacientes (2013-2017), los ingresos a diálisis de los mismos y la mortalidad por todas las causas en Perú. La adherencia al programa se estableció con el cumplimiento de visitas mínimas durante su primer año de seguimiento. La efectividad de la adherencia al programa se midió en términos de debut a hemodiálisis o muerte por todas las causas. Se utilizaron curvas de Kaplan-Meier, test de diferencias en la distribución (Log-Rank test) y métodos de análisis de supervivencia. Los análisis se realizaron utilizando R estudio 3.5.0 RESULTADOS Fueron evaluados 20.354 participantes, 54,1% varones, edad media de 72,1 años, con un seguimiento medio de 2,2 años; 15.279 (75.1%) tuvieron ERC en estadios tempranos (estadio 1 al 3a). La adherencia disminuyó en un 41,0% el riesgo de terapia de reemplazo renal (HR = 0,59; IC95% 0,41–0,85) en el grupo de bajo riesgo y en un 31,0% (HR = 0,69; IC95% 0,57–0,83) la mortalidad en el grupo de alto riesgo. CONCLUSIONES La estrategia de cuidado multidisciplinario con evaluaciones estandarizadas según estadio es efectiva en reducir el ingreso a terapia de reemplazo renal cuando se identifica al paciente en estadios tempranos y en reducir la mortalidad en estadios avanzados.

RESUMO | Objetivo: Estimar a prevalência de cegueira e deficiência visual em idosos que vivem na Guatemala. Métodos: Indivíduos com idade ³50 anos foram selecionados por amostragem aleatória por conglomerados, e os participantes do estudo foram avaliados pelo método de Avaliação Rápida da Cegueira Evitável. A acuidade visual foi medida e o cristalino foi examinado. Se a acuidade visual apresentada fosse <20/60, então também foi testada com um buraco estenopeico e a fundoscopia realizada. A cegueira e a deficiência visual foram classificadas como deficiência visual moderada com acuidade visual <20/60-20/200; deficiência visual grave com acuidade visual <20/200-20/400; ou cegueira com acuidade visual <20/400. A principal causa de cegueira ou deficiência visual em cada olho foi determinada, e naqueles com catarata, as barreiras ao tratamento foram avaliadas. Resultados: O estudo incluiu 3.850 pessoas com ³50 anos de idade; 3.760 (97,7%) foram examinadas. A prevalência de cegueira ajustada à idade e ao sexo foi de 2,9% (intervalo de confiança de 95%, 2,0-3,8%), 5,2% (4,0-6,4%) deficiência visual grave e 27,6% (23,3-32,0%) deficiência visual moderada. A catarata foi a principal de cegueira (77,6%), seguida de outras doenças do segmento posterior (6,0%). Catarata causada por 79,4% de deficiência visual grave, enquanto erros refrativos não corrigidos causaram 67,9% de deficiência visual moderada. Após a cirurgia de catarata, 75% dos participantes tiveram uma acuidade de 20/200, ou melhor, e 19,0% a deficiência visual não foi melhor do que 20/200 com a correção. O custo foi a principal barreira à cirurgia de catarata (56.7%). Conclusões: A prevalência de cegueira em idosos é maior na Guatemala do que na maioria dos outros países da América Central. A maioria dos casos de cegueira e deficiência visual era evitável ou tratável. O aumento da disponibilidade de tratamento de catarata a preços acessíveis e de alta qualidade teria um impacto substancial na prevenção da cegueira.

ABSTRACT | Purpose: To estimate the prevalence of blindness and visual impairment in older adults living in Guatemala. Methods: Participants ³50 years of age were selected using random cluster sampling and evaluated using the Rapid Assessment of Avoidable Blindness method. Visual acuity was measured, and the lens was examined. If presenting visual acuity was <20/60, it was also tested with a pinhole and fundoscopy was performed. Blindness and visual impairment were classified as moderate visual impairment (presenting visual acuity <20/60 to 20/200), severe visual impairment (presenting visual acuity <20/200 to 20/400), or blindness (presenting visual acuity <20/400). The primary cause of blindness or visual impairment in each eye was determined, and if the cause was cataracts, the barriers to treatment were assessed. Results: The study included 3,850 people ³50 years of age, of whom 3,760 (97.7%) were examined. The age- and sex-adjusted prevalence of blindness was 2.9% (95% confidence interval, 2.0%-3.8%), while 5.2% (4.0%-6.4%) presented with severe visual impairment, and 27.6% (23.3%-32.0%) presented with moderate visual impairment. Cataracts were the leading cause of blindness (77.6%), followed by other posterior segment diseases (6.0%). Cataracts caused 79.4% of cases of severe visual impairment, while uncorrected refractive errors caused 67.9% of cases of moderate visual impairment. Following cataract surgery, 75% of participants had a presenting visual acuity of 20/200 or better, and in 19.0% of participants, visual acuity was not better than 20/200 with correction. Cost was the main barrier to cataract surgery (56.7%). Conclusions: The prevalence of blindness in older adults is higher in Guatemala than in most Central American countries. Most cases of blindness and visual impairment were either preventable or treatable. Increased availability of affordable, high-quality cataract treatment would have a substantial impact on blindness prevention.

Abstract Background: Procedures to remove adiposities and skin, such as dermolipectomy, can develop wounds that are difficult to heal by conventional therapies. Mesenchymal stem cells are indicated as potential candidates for regenerative therapy in wounds, due to their multipotentiality, low immunogenicity, modulating capacity of inflammation and tissue modeling processes. Case report: Patient with dehiscent chronic ulcer secondary to dermolipectomy, who received cutaneous treatment with mesenchymal stem cells. The therapy induced scar formation and neovascularization, as well as the decrease of infiltrated leukocytes and proinflammatory cytokines. Mesenchymal cells are proposed as an interesting alternative for the treatment of postoperative lesions.

Resumen Introducción: Los procedimientos para retirar adiposidades y piel, como la dermolipectomía, pueden desarrollar heridas difíciles de sanar mediante tratamientos convencionales. Se ha señalado que es posible utilizar las células madre mesenquimales en el tratamiento regenerativo en heridas, en virtud de su multipotencialidad, baja inmunogenicidad, capacidad moduladora de inflamación y procesos modeladores de tejidos. Caso clínico: Paciente con dehiscencia en úlcera crónica secundaria a dermolipectomía, sometida a tratamiento cutáneo con células madre mesenquimales. Se indujo formación de cicatriz y neovascularización, así como la disminución de leucocitos infiltrados y citocinas proinflamatorias. Se propone a las células mesenquimales como una alternativa interesante para el tratamiento de lesiones postoperatorias.

Abstract CRISPR/Cas system constitutes a prokaryotic adaptive immune system against the incorporation of exogenous genetic material. This immunity system is mediated by a specific nuclease that breaks invasive DNA and later some particles of the broken DNA are stored to recognize and eliminate similar sequences in the future. Recently, it was found that the system could be reprogrammed to recognize any DNA sequence and it was possible to introduce highly specific genetic editions in a huge number of organisms. Furthermore, CRISPR/Cas system has been adapted for the development of a highly specific strategy in the treatment of infections caused by antimicrobial-resistant bacteria. In this review it was described in a general manner the biological origin of CRISPR/Cas system, the mechanism of genetic edition based on it, the employ of the system in the development of a specific treatment method for bacterial infections, and finally some limitations of the system were discussed.

Resumen El sistema CRISPR/Cas es parte de un sistema inmune adaptativo que los organismos procariotas desarrollaron para defenderse de la incorporación de material genético exógeno. Este sistema de inmunidad está mediado por una nucleasa específica que degrada al DNA invasor y posteriormente algunos fragmentos de la molécula degradada se almacenan para reconocer y eliminar secuencias similares en el futuro. Recientemente fue posible reprogramar este sistema para reconocer cualquier secuencia de DNA y realizar ediciones genéticas en una gran cantidad de organismos de manera altamente específica. El sistema CRISPR/Cas ha sido adaptado para el desarrollo de una estrategia altamente específica en el tratamiento de infecciones producidas por bacterias resistentes a antimicrobianos. En esta revisión se describe de manera general el origen biológico del sistema CRISPR/Cas, el mecanismo de edición genética desarrollado con base en él, la aplicación del sistema en el desarrollo de un método específico para tratar infecciones bacterianas y finalmente se discutirán algunas limitaciones del sistema.

Abstract Background: Although the mesquite (mesquital or mezquital in Spanish) is one of the representative ecosystems of the landscapes in the north of Mexico, it is also one of the least studied. This study evaluated the structure (horizontal and vertical) and diversity of a plant community of mesquite in Northeastern Mexico. Three plots of 1,600 m2 each were established. All trees and shrubs with a basal diameter (d0.10) ≥ 0.5 cm were recorded, and total height (h) and crown diameter (dcrown) were measured. Results: There were 8 families, 12 genera and 14 species. The genus presenting the most species was Acacia (three species). The most representative family was Fabaceae with seven species. The evaluated community presents a density of 375 N/ha and a crown area of 6,600 m2/ha. The species with the highest values on the Importance Value Index (IVI) were Prosopis glandulosa (15.95%), Acacia amentacea (14.50%), Havardia pallens (14.27%) and Acacia farnesiana (11.22%). These four species account for 55.94% of IVI. The value obtained from the Vertical Species Profile Index (A) was 3.03, with an Amax of 3.74 and an Arel of 81.15%, indicating high structural diversity in the high strata. The evaluated plant community had a Margalef Diversity Index value of DMg = 2.50 and a Shannon Index value of H' = 2.28, values which are intermediate and considered to be common in the scrublands of Northeastern Mexico. Conclusions: 1) The studied community presents intermediate values that are considered as common in comparison to other arid and semi-arid vegetation associations of Northeastern Mexico. 2) The abundance curve of the species was well adjusted to the geometric model, and the distribution is associated with adverse environments such as semi-arid. 3) The family with greater importance for its contribution to the community is Fabaceae, while the genus with more species was Acacia. The research generated quantitative information of the plant community of a mesquite which is in a phase of mature ecological succession.

Abstract This paper studies the efficiently use of resources to generate income and reduce inequality, considering non-controllable variables in the 32 states of Mexico during the 1990-2010 period. To define efficiency, we use the Data Envelopment Analysis (DEA), considering as a bad output the poverty of capacities and as a uncontrollable variable the average level of schooling of the population aged 15 or older. The results shows that only Baja California Sur, Campeche and the Federal District were efficient in generating income and reducing inequality.

Resumen El documento aborda el estudio del uso eficiente de los recursos para generar ingreso y reducir la inequidad, considerando variables no controlables, en las 32 entidades de México, durante el período 1990-2010. Para determinar la eficiencia, se utilizó el Análisis de la Envolvente de Datos (DEA), considerando como bad output a la pobreza de capacidades, y como variable no controlable, el grado promedio de escolarización de la población de 15 y más años. Los resultados muestran que sólo Baja California Sur, Campeche y el Distrito Federal fueron eficientes en la generación de ingreso y en la reducción de inequidad.