Especies de arañas como agentes de control biológico natural de la “cigarrita marrón” (Tagosodes orizicolus Muir) en el cultivo de arroz en el valle de Tumbes

Las arañas son parte de la fauna benéfica presente en los agroecosistemas de arroz en Tumbes y cumplen un rol fundamental como agentes de biocontrol de Tagosodes orizicolus Muir. Se hace necesario conocer su biodiversidad para integrarlas en el manejo integrado de plagas. El objetivo del estudio fue identificar las especies y sus fluctuaciones poblacionales en el cultivo de arroz en el valle de Tumbes. El primer periodo de evaluación fue durante octubre 2018 a enero 2019 en cultivos sembrados bajo la modalidad de trasplante y de abril a junio de 2019 de siembra directa. Las colectas fueron semanales, las técnicas de colecta fueron trampas de caída, observación directa en un determinado número de plantas por m2 y barrido con red entomológica. El material colectado fue llevado a los ambientes del museo entomológico para su procesamiento, identificación y conservación. Se recolectaron ejemplares pertenecientes a 18 familias, las más representativas fueron Lycosidae (65,05%), Tetragnathidae (15,15%) y Oxyopidae (6,48%). Se identificaron 37 especies y/o morfoespecies. Las más abundantes fueron Hogna albemarlensis (45,57%), Arctosa minuta (12,46%) y Tetragnatha nitens (10,63%). Este estudio representa la primera contribución al conocimiento de la diversidad de arañas presentes en el cultivo de arroz en el valle de Tumbes

Parasitoides de la cigarrita marrón Tagosodes orizicolus Muir (Hemiptera: Delphacidae), insecto plaga del cultivo de arroz

Las poblaciones de Tagosodes orizicolus Muir, insecto plaga clave del cultivo de arroz en el valle de Tumbes, son reguladas por enemigos naturales predadores y parasitoides.  El objetivo del estudio fue identificar especies de parasitoides. Durante noviembre 2018 a junio 2019, se recolectaron semanalmente hojas de arroz conteniendo huevos; adultos y ninfas recolectadas con red entomológica y llevadas al Museo de Entomología de la Universidad Nacional de Tumbes, en las hojas se realizaron disecciones, se retiró la parte conteniendo los huevos, se depositaron en tubos de ensayo para esperar la emergencia de cigarritas o parasitoides para su identificación y preservación. Los adultos y ninfas fueron revisados para detectar presencia de ectoparasitoides.  Se utilizaron las claves para especies de himenópteros neotropicales y subtropicales de Huber y Pinto. Se recuperaron dos especies, una perteneciente al género Anagrus (Mymaridae) y la otra al género Paracentrobia (Trichogrammatidae). El mayor porcentaje de parasitismo fue de 16,7% al 47,7% para Anagrus y 2,1% al 39,3% para Paracentrobia. No se recuperaron parasitoides de los otros estados de desarrollo.  Se concluye que existen especies de parasitoides de huevos en el valle de Tumbes y para su multiplicación y protección natural hay que brindarles corredores biológicos

Influencia de la alimentación con hoja de arroz (Oryza sativa L.) en la biología de Spodoptera frugiperda (J.E. Smith, 1797)

Spodoptera frugiperda incide en el desarrollo y rendimiento del cultivo de arroz, por tal razón se realizó durante tres generaciones un estudio para demostrar la influencia de la alimentación con hojas de tres variedades de arroz en su biología, bajo condiciones de laboratorio. Se criaron individualmente 25 larvas en placas Petri por variedad, alimentándolas diariamente con hojas de la variedad correspondiente. La temperatura promedio fue de 26,33 °C y humedad relativa de 84,33%. Los resultados indican que el periodo de incubación fue de 4,0 días para las tres variedades, el larval tuvo una duración promedio en las tres generaciones de 14,27 ± 0,16 días en Tinajones, 13,77 ± 0,13 en Feron y 13,50 ± 0,17 en Mallares, el estado de pre-pupa 2,1± 0,10 días en Ferón, 2,0 en Mallares y 2,60 ± 0,17 en Tinajones. En el caso de la pupa 8,80 ± 0,20 días en Feron, 7,73 ± 0,5 en Mallares y 9,53±0,20 en Tinajones. El ciclo de desarrollo tuvo una duración de 28,67 ± 0,27 días en Ferón, 27,23 ± 0,27 en Mallares y 30,40 ± 0,30 en la variedad Tinajones. Se concluye que las variedades de arroz tienen una ligera influencia en la biología de la especie en estudio

Treat-and-extend versus fixed bimonthly treatment regimens for treatment-naive neovascular age-related macular degeneration: real world data from the Fight Retinal Blindness registry

Purpose To compare the outcomes of two different antivascular endothelial growth factor treatment regimens for treatment-naive eyes with neovascular age-related macular degeneration in routine clinical care at 12 and 24 months in Spain. Methods Observational study using the Fight Retinal Blindness (FRB) outcomes registry platform. Eyes were treated with fixed bimonthly (FB) aflibercept group at one center and a treat-and-extend (TAE) regimen using either aflibercept or ranibizumab at the other center. Results We included 192 eyes. Of these, 160 eyes (83%) completed 12 months (86 TAE and 74 FB) and 79 (41%) completed 24 months (46 for TAE and 33 for FB) of follow-up. No statistically significant differences (p > 0.05) were found regarding mean visual acuity (VA, logMAR letters) at baseline (12 month cohort TAE 59.6 vs FB 57.9; 24 month cohort TAE 61.7 vs FB 62.6), final meanVA (12 month cohort TAE 61.1 vs FB 63.0; 24 month cohort TAE 64.8 vs FB 66.4), and median number of injections (12 months TAE 7 vs FB 7; 24 months TAE 11 vs FB 12). However, the distribution of injection frequencies for the TAE group was larger, with 35% of TAE eyes receiving ! 6 injections at 12 months compared with only 19% of FB eyes (p = 0.024). Conclusion Similar VA results were observed with TAE and FB regimens, with no differences in the median number of injections. However, the TAE approach seemed to deliver a wider distribution of injection frequencies due to its individualized approach, which may help reduce the burden of injections in some eyes

Creation of a neovascular age-related macular degeneration national database using a web-based platform: Fight Retinal Blindness Spain. Report 1: Visual outcomes

Background: To study the visual outcomes of neovascular AMD (nAMD) treated with anti-vascular endothelial growth factor (VEGF) drugs at national level. Methods: Multicenter national database of nAMD eyes treated with anti-VEGF intravitreal injections (ranibizumab, aflibercept, bevacizumab) in fixed bimonthly (FB) or treat-and-extend (TAE) regimens. Demographics, visual acuity (VA) in logarithm of the minimum angle of resolution (logMAR) ETDRS letters at baseline and subsequent visits, number of injections and visits data were collected using a validated web-based tool (Fight Retinal Blindness!). Results: 1273 eyes (1014 patients) were included, 971 treatment naïve (TN) and 302 previously treated (PT). Baseline VA (mean ± SD) was 57.5 (±19.5) and 62.2 (±17) (p > 0.001), and 24 months final VA was 60.4 (±21.2) and 58.8 (±21.1) (p = 0.326), respectively. Mean VA change at 12/24 months was +4.2/+2.9 letters in TN eyes and +0.1/-3.4 letters in PT eyes (p < 0.001/p < 0.001). The percentage of ≥15 letters gainers/losers at 24 months was 24.8%/14.5% in TN, and 10.3%/15.7% in PT eyes. The median number of injections/visits at 12 months was 7/9 in TN and 6/8 in PT (p = 0.002/p < 0.001) and at 24 months was 11/16 in TN and 11/14 in PT (p = 0.329/p < 0.001). Study drugs included ranibizumab (39.5%), aflibercept (41.2%) and bevacizumab (19.3%). Conclusion: Independent, large-scale national audits are feasible if committed health care professionals are provided with efficient information technology systems to do them. The results described here represent an adequate measurement of the quality of care delivered nationwide and benchmark the clinical management of nAMD at a country level compared to other real-world international cohorts. Keywords: aflibercept; age-related macular degeneration; audit; benchmark standard; bevacizumab; national database; national dataset; neovascular AMD; ranibizumab

ABORTO RETENIDO CON FETOS TORACOPAGOS

Se presenta el caso de una paciente que consulta por síntomas de aborto, detectándose aborto retenido de 9 semanas con fetos toracopagos, que se confirma con el examen macroscópico luego de la evacuación uterin

Revolutionizing Alzheimer\u27s disease and clinical trials through biomarkers

AbstractThe Alzheimer's Association's Research Roundtable met in May 2014 to explore recent progress in developing biomarkers to improve understanding of disease pathogenesis and expedite drug development. Although existing biomarkers have proved extremely useful for enrichment of subjects in clinical trials, there is a clear need to develop novel biomarkers that are minimally invasive and that more broadly characterize underlying pathogenic mechanisms, including neurodegeneration, neuroinflammation, and synaptic dysfunction. These may include blood-based assays and new neuropsychological testing protocols, as well as novel ligands for positron emission tomography imaging, and advanced magnetic resonance imaging methodologies. In addition, there is a need for biomarkers that can serve as theragnostic markers of response to treatment. Standardization remains a challenge, although international consortia have made substantial progress in this area and provide lessons for future standardization efforts

Pangenome comparison of Bacteroides fragilis genomospecies unveils genetic diversity and ecological insights

Bacteroides fragilis is a Gram-negative commensal bacterium commonly found in the human colon, which differentiates into two genomospecies termed divisions I and II. Through a comprehensive collection of 694 B. fragilis whole genome sequences, we identify novel features distinguishing these divisions. Our study reveals a distinct geographic distribution with division I strains predominantly found in North America and division II strains in Asia. Additionally, division II strains are more frequently associated with bloodstream infections, suggesting a distinct pathogenic potential. We report differences between the two divisions in gene abundance related to metabolism, virulence, stress response, and colonization strategies. Notably, division II strains harbor more antimicrobial resistance (AMR) genes than division I strains. These findings offer new insights into the functional roles of division I and II strains, indicating specialized niches within the intestine and potential pathogenic roles in extraintestinal sites.ImportanceUnderstanding the distinct functions of microbial species in the gut microbiome is crucial for deciphering their impact on human health. Classifying division II strains as Bacteroides fragilis can lead to erroneous associations, as researchers may mistakenly attribute characteristics observed in division II strains to the more extensively studied division I B. fragilis. Our findings underscore the necessity of recognizing these divisions as separate species with distinct functions. We unveil new findings of differential gene prevalence between division I and II strains in genes associated with intestinal colonization and survival strategies, potentially influencing their role as gut commensals and their pathogenicity in extraintestinal sites. Despite the significant niche overlap and colonization patterns between these groups, our study highlights the complex dynamics that govern strain distribution and behavior, emphasizing the need for a nuanced understanding of these microorganisms

Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases

Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests