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1.
Development ; 150(6)2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36806912

RESUMEN

Proper muscle contraction requires the assembly and maintenance of sarcomeres and myofibrils. Although the protein components of myofibrils are generally known, less is known about the mechanisms by which they individually function and together synergize for myofibril assembly and maintenance. For example, it is unclear how the disruption of actin filament (F-actin) regulatory proteins leads to the muscle weakness observed in myopathies. Here, we show that knockdown of Drosophila Tropomodulin (Tmod), results in several myopathy-related phenotypes, including reduction of muscle cell (myofiber) size, increased sarcomere length, disorganization and misorientation of myofibrils, ectopic F-actin accumulation, loss of tension-mediating proteins at the myotendinous junction, and misshaped and internalized nuclei. Our findings support and extend the tension-driven self-organizing myofibrillogenesis model. We show that, like its mammalian counterpart, Drosophila Tmod caps F-actin pointed-ends, and we propose that this activity is crucial for cellular processes in different locations within the myofiber that directly and indirectly contribute to the maintenance of muscle function. Our findings provide significant insights to the role of Tmod in muscle development, maintenance and disease.


Asunto(s)
Actinas , Tropomodulina , Animales , Actinas/metabolismo , Tropomodulina/genética , Tropomodulina/metabolismo , Proteínas de Microfilamentos/metabolismo , Drosophila/genética , Drosophila/metabolismo , Miofibrillas/metabolismo , Citoesqueleto de Actina/metabolismo , Sarcómeros/metabolismo , Mamíferos/metabolismo
2.
BMC Cancer ; 23(1): 678, 2023 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-37468881

RESUMEN

BACKGROUND: Interindividual survival and recurrence rates in cases of locoregional colon cancer following surgical resection are highly variable. The aim of the present study was to determine whether elevated pre-operative and post-operative CEA values are useful prognostic biomarkers for patients with stage I-III colon cancer who underwent surgery with curative intent. METHODS: We conducted a retrospective study in patients with histologically confirmed stage I-III primary colonic adenocarcinoma who underwent radical surgical resection at Mexico's National Cancer Institute, between January 2008 and January 2020. We determined pre-operative and post-operative CEA and analyzed the association of scores with poorer survival outcomes in patients with resected colon cancer, considering overall survival (OS) and disease-free survival (DFS). RESULTS: We included 640 patients with stage I-III colon cancer. Pre-operative CEA levels were in the normal range in 460 patients (group A) and above the reference value in the other 180. Of the latter, 134 presented normalized CEA levels after surgery, but 46 (group C) continued to show CEA levels above the reference values after surgery. Therefore, propensity score matching (PSM) was carried out to reduce the bias. Patients were adjusted at a 1:1:1 ratio with 46 in each group, to match the number in the smallest group. Median follow- up was 46.4 months (range, 4.9-147.4 months). Median DFS was significantly shorter in Group C: 55.5 months (95% CI 39.6-71.3) than in the other two groups [Group A: 77.1 months (95% CI 72.6-81.6). Group B: 75.7 months (95% CI 66.8-84.5) (p-value < 0.001)]. Overall survival was also significantly worse in group C [57.1 (95% CI 37.8-76.3) months] than in group A [82.8 (95% CI 78.6-86.9 months] and group B [87.1 (95% CI 79.6-94.5 months] (p-value = 0.002). To identify whether change in CEA levels operative and post-surgery was an independent prognostic factor for survival outcomes, a Cox proportional hazard model was applied. In multivariate analysis, change in CEA level was a statistically significant, independent prognostic factor for overall survival (p-value = 0.031). CONCLUSIONS: When assessed collectively, pre-operative and post-operative CEA values are useful biomarkers for predicting survival outcomes in patients with resected colon cancer. Prognoses are worse for patients with elevated pre-operative and post-surgical CEA values, but similar in patients with normal post-surgical values, regardless of their pre-surgery values.


Asunto(s)
Antígeno Carcinoembrionario , Neoplasias del Colon , Humanos , Estudios Retrospectivos , Neoplasias del Colon/cirugía , Neoplasias del Colon/patología , Pronóstico , Supervivencia sin Enfermedad , Biomarcadores de Tumor , Estadificación de Neoplasias
3.
Int J Colorectal Dis ; 38(1): 158, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37261538

RESUMEN

BACKGROUND: After tumor resection, a preventive diverting loop ileostomy creation is a routine surgical procedure to prevent anastomotic leakage and infections and to preclude secondary surgeries. Despite its benefits, several studies have proposed potential complications that extend the disease course by impairing the feasibility of adjuvant chemotherapy and adherence. PURPOSE: The aim of this study was to evaluate the impact of ileostomy complications on the adherence to adjuvant treatment and overall survival (OS) of colon cancer (CC) patients. METHODS: Retrospective, observational study. Patients diagnosed with colon adenocarcinoma were treated between January 2010 and December 2020 at the National Cancer Institute in Mexico. STATISTICAL ANALYSIS: χ2 and t-test, Kaplan-Meier, log-rank, and Cox regression. Statistical significance differences were assessed when p was bilaterally < 0.05. RESULTS: The most frequent complications of loop-derived ileostomy were hydro-electrolytic dehydration (50%), acute kidney injury (AKI) (26%), grade 1-2 diarrhea (28%), and grade 3-4 diarrhea (21%) (p = 0.001). Patients with complete chemotherapy did not reach the median OS. In contrast, the median OS for patients with non-complete chemotherapy was 56 months (p = 0.023). Additionally, 5-year OS reached to 100% in the early restitution group, 85% in the late restitution group, and 60% in the non-restitution group (p = 0.016). Finally, AKI (p = 0.029; 95% confidence interval (CI) 3.348 [1.133-9.895]), complete chemotherapy (p = 0.028; 95% CI 0.376 [0.105-0.940]), and reversed ileostomy (p = 0.001; 95% CI 0.125 [0.038-0.407]) remained as predictors of overall survival for patients with CC treated with a loop ileostomy. CONCLUSIONS: Our results emphasize the early stoma reversal restitution as a safe and feasible alternative to prevent severe complications related to ileostomies which improve chemotherapy adherence and overall survival of colon cancer patients. This is one of the pioneer studies analyzing the impact of ileostomy on treatment adherence and outcome of Latin American patients with colon cancer. TRIAL REGISTRATION: Retrospective study No. 2021/045, in April 2021.


Asunto(s)
Lesión Renal Aguda , Adenocarcinoma , Neoplasias del Colon , Neoplasias del Recto , Humanos , Ileostomía/efectos adversos , Ileostomía/métodos , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/cirugía , Neoplasias del Colon/complicaciones , Estudios Retrospectivos , Adenocarcinoma/cirugía , Anastomosis Quirúrgica/efectos adversos , Resultado del Tratamiento , Diarrea/complicaciones , Lesión Renal Aguda/etiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Neoplasias del Recto/cirugía
4.
Int J Mol Sci ; 24(8)2023 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-37108372

RESUMEN

The Unfolded protein response (UPR), triggered by stress in the endoplasmic reticulum (ER), is a key driver of neurodegenerative diseases. GM2 gangliosidosis, which includes Tay-Sachs and Sandhoff disease, is caused by an accumulation of GM2, mainly in the brain, that leads to progressive neurodegeneration. Previously, we demonstrated in a cellular model of GM2 gangliosidosis that PERK, a UPR sensor, contributes to neuronal death. There is currently no approved treatment for these disorders. Chemical chaperones, such as ursodeoxycholic acid (UDCA), have been found to alleviate ER stress in cell and animal models. UDCA's ability to move across the blood-brain barrier makes it interesting as a therapeutic tool. Here, we found that UDCA significantly diminished the neurite atrophy induced by GM2 accumulation in primary neuron cultures. It also decreased the up-regulation of pro-apoptotic CHOP, a downstream PERK-signaling component. To explore its potential mechanisms of action, in vitro kinase assays and crosslinking experiments were performed with different variants of recombinant protein PERK, either in solution or in reconstituted liposomes. The results suggest a direct interaction between UDCA and the cytosolic domain of PERK, which promotes kinase phosphorylation and dimerization.


Asunto(s)
Gangliosidosis GM2 , Enfermedad de Sandhoff , Animales , Atrofia , Gangliosidosis GM2/metabolismo , Neuritas/metabolismo , Enfermedad de Sandhoff/terapia , Ácido Ursodesoxicólico/farmacología , eIF-2 Quinasa/metabolismo
5.
Proc Biol Sci ; 289(1972): 20220086, 2022 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-35382601

RESUMEN

Modern agriculture is becoming increasingly pollinator-dependent. However, the global stock of domesticated honeybees is growing at a slower rate than its demand, while wild bees are declining worldwide. This uneven scenario of high pollinator demand and low pollinator availability can translate into increasing pollination limitation, reducing the yield of pollinator-dependent crops. However, overall assessments of crop pollination limitation and the factors determining its magnitude are missing. Based on 52 published studies including 30 crops, we conducted a meta-analysis comparing crop yield in pollen-supplemented versus open-pollinated flowers. We assessed the overall magnitude of pollination limitation and whether this magnitude was influenced by (i) the presence/absence of managed honeybees, (ii) crop compatibility system (i.e. self-compatible/self-incompatible) and (iii) the interaction between these two factors. Overall, pollen supplementation increased yield by approximately 34%, indicating sizable pollination limitation. Deployment of managed honeybees and self-compatibility were associated with lower pollination limitation. Particularly, active honeybee management decreased pollination limitation among self-compatible but apparently not among self-incompatible crops. These findings indicate that current pollination regimes are, in general, inadequate to maximize crop yield, even when including managed honeybees, and stress the need of transforming the pollination management paradigm of agricultural landscapes.


Asunto(s)
Productos Agrícolas , Polinización , Agricultura , Animales , Abejas , Flores , Polen
6.
RNA ; 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-33323527

RESUMEN

Transition through cell cycle phases requires temporal and spatial regulation of gene expression to ensure accurate chromosome duplication and segregation. This regulation involves dynamic reprogramming of gene expression at multiple transcriptional and posttranscriptional levels. In transcriptionally silent oocytes, the CPEB-family of RNAbinding proteins coordinates temporal and spatial translation regulation of stored maternal mRNAs to drive meiotic progression. CPEB1 mediates mRNA localization to the meiotic spindle, which is required to ensure proper chromosome segregation. Temporal translational regulation also takes place in mitosis, where a large repertoire of transcripts are activated or repressed in specific cell cycle phases. However, whether control of localized translation at the spindle is required for mitosis is unclear, as mitotic and acentriolar-meiotic spindles are functionally and structurally different. Furthermore, the large differences in scale-ratio between cell volume and spindle size in oocytes compared to somatic mitotic cells may generate distinct requirements for gene expression compartmentalization in meiosis and mitosis. Here we show that mitotic spindles contain CPE-localized mRNAs and translating ribosomes. Moreover, CPEB1 and CPEB4 localize in the spindles and they may function sequentially in promoting mitotic stage transitions and correct chromosome segregation. Thus, CPEB1 and CPEB4 bind to specific spindle-associated transcripts controlling the expression and/or localization of their encoded factors that, respectively, drive metaphase and anaphase/cytokinesis.

7.
Retina ; 41(10): 2048-2058, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-33675333

RESUMEN

PURPOSE: To evaluate the outcomes and safety of retropupillary iris-claw intraocular lens implantation and associated pars plana vitrectomy. METHODS: Multicenter, national audit of 325 eyes (325 patients). Demographics, surgical details, and complications are described. Visual acuity, intraocular pressure, and central retinal thickness assessed by optical coherence tomography were collected at 1, 3, 6, and 12 months after surgery. Kaplan-Meier curves were created to assess the cumulative probability of postoperative visual acuity and intraocular pressure levels, macular edema development, and corneal decompensation. RESULTS: The cumulative probability of the final visual acuity ≤0.3 logarithm of the minimum angle of resolution (≥20/40 Snellen) was 75.6% at 12-month follow-up. The probability of intraocular pressure >21, ≥25, and ≥30 mmHg was 48.1%, 33.1%, and 19.0%, and the probability of intraocular pressure-lowering drops was 50.9% at 12 months. Glaucoma surgery was required in 4.3% of the eyes (14/325). The cumulative probability of macular edema was 20.5% at 12 months and was greater in complicated cataract surgery than in intraocular lens-luxation eyes (26% vs. 16.7%, P = 0.04). Corneal transplantation was required in 2.8% of the eyes (9/325). CONCLUSION: This study on 325 eyes with aphakia or intraocular lens dislocation managed with the retropupillary iris-claw intraocular lens technique provides clinical outcomes in a real-world scenario, reporting relevant data for patient counseling and preoperative discussions.


Asunto(s)
Afaquia Poscatarata/cirugía , Iris/cirugía , Implantación de Lentes Intraoculares , Lentes Intraoculares , Auditoría Médica , Vitrectomía , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Afaquia Poscatarata/fisiopatología , Femenino , Humanos , Presión Intraocular/fisiología , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Estudios Retrospectivos , Microscopía con Lámpara de Hendidura , Tomografía de Coherencia Óptica , Resultado del Tratamiento , Agudeza Visual/fisiología
8.
Neuroophthalmology ; 45(1): 61-64, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33762792

RESUMEN

Macular oedema is a rare complication of fingolimod treatment. It usually presents within 3-4 months, but occasionally presents later. It can resolve without treatment despite continuation of fingolimod treatment. Herein we report a case of very late onset macular oedema in a 49-year-old woman with multiple sclerosis treated with fingolimod for 7 years. The patient presented with blurred vision in both eyes with visual acuities of 20/32 in her right eye and 20/25 in her left eye. She had macular oedema, that without discontinuing fingolimod treatment, resolved after 1 month.

9.
BMC Ophthalmol ; 20(1): 443, 2020 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-33176749

RESUMEN

BACKGROUND: To identify different response patterns to intravitreal dexamethasone implants (IDI) in naïve and previously treated (PT) diabetic macular edema (DME) eyes in a real-life setting. METHODS: 342 IDI injections (203 DME eyes) were included. Number of IDI injections, percentage (%) of eyes with 1, 2, 3 and ≥ 4 injections, time to reinjections, visual acuity (VA), intraocular pressure (IOP) and central retinal thickness (CRT) were evaluated for naïve and PT DME eyes over 24 months. RESULTS: Mean number of injections was significantly lower in naïve vs PT DME eyes (1.40 ± 0.9 vs 1.82 ± 0.9, p < 0.001). The percentage of eyes receiving 1 injection was significantly higher in naïve vs PT DME eyes (76.1 vs 47.7), (p < 0.001). However, it was significantly lower for 2 (16.4 vs 29.4), or 3 injections (1.4 vs 17.6) (both p < 0.001), with no differences in eyes receiving ≥4 injections (5.9 vs 5.1 respectively, p = 0.80). Mean time to reinjection was not significantly different between both groups for the second, third and fourth injection (9.6 ± 4.0 vs 10.0 ± 5.5, p = 0.75, 13.2 ± 4.0 vs 16.0 ± 3.5, p = 0.21 and 21.7 ± 3.8 vs 19.7 ± 5.8, p = 0.55). VA scores were consistently better in naïve vs PT DME eyes at all studied timepoints, with no significant differences in CRT reduction or adverse effect rates. CONCLUSION: Naïve DME eyes received lower number of IDI injections and showed better VA levels than PT DME eyes for 24 months in a real-world setting. This data supports the IDI use in early DME stages and provide further evidence of better IDI response when used as first-line therapy.


Asunto(s)
Diabetes Mellitus , Retinopatía Diabética , Edema Macular , Dexametasona/uso terapéutico , Retinopatía Diabética/tratamiento farmacológico , Implantes de Medicamentos , Glucocorticoides/uso terapéutico , Humanos , Inyecciones Intravítreas , Edema Macular/tratamiento farmacológico , Estudios Retrospectivos
10.
Gac Med Mex ; 156(1): 40-46, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32026880

RESUMEN

INTRODUCTION: Medical students report higher levels of anxiety than students from other majors. Knowledge about their psychological well-being is scarce. OBJECTIVE: To identify sociodemographic and academic factors that predict the level of anxiety and psychological well-being in Mexican medical students. METHOD: Cross-sectional study of Mexican medical students of first (n = 59), third (n = 43) and fifth semester (n = 59), who answered a sociodemographic questionnaire, Beck Anxiety Inventory, the Psychological Well-being Scale for adults and the Family Adaptability and Cohesion Evaluation Scale. RESULTS: Females showed higher levels of anxiety (p < 0.01). Anxiety in males was similar in the different semesters (p > 0.05); women of third and fifth semesters were more anxious than those at first semester (p < 0.01). Anxiety and psychological well-being were negatively correlated (p < 0.001). The "Less anxiety, higher level of well-being" and "More anxiety, lower level of well-being" subgroups were characterized, and a logistic regression identified that being a woman (OR = 4.70) and not practicing any religion (OR = 2.49) are predictive factors of higher levels of anxiety. CONCLUSIONS: Female medical students constitute a population at risk for higher levels of anxiety and less psychological well-being, which compromises their learning, quality of life and future professional practice.


INTRODUCCIÓN: Estudiantes de medicina reportan mayor ansiedad que estudiantes de otras carreras. El conocimiento sobre su bienestar psicológico es escaso. OBJETIVO: Identificar factores sociodemográficos y académicos predictores del nivel de ansiedad y bienestar psicológico en estudiantes mexicanos de medicina. MÉTODO: Estudio transversal de estudiantes mexicanos de medicina de primer (n = 59), tercer (n = 43) y quinto semestre (n = 59), que contestaron un cuestionario sociodemográfico, la Escala de Ansiedad de Beck, la Escala de Bienestar Psicológico para Adultos y la Escala de Evaluación de la Cohesión y la Adaptabilidad Familiar. RESULTADOS: Las mujeres presentaron mayor ansiedad (p < 0.01). La ansiedad en hombres fue similar en los distintos semestres (p > 0.05); las mujeres de tercer y quinto semestre fueron más ansiosas que las del primero (p < 0.01). Ansiedad y bienestar psicológico correlacionaron negativamente (p < 0.001). Se identificaron los subgrupos "Menor ansiedad, mayor bienestar" y "Mayor ansiedad, menor bienestar", y una regresión logística identificó que ser mujer (OR = 4.70) y no profesar alguna religión (OR = 2.49) son factores predictores de mayor ansiedad. CONCLUSIONES: Las estudiantes de medicina constituyen una población de riesgo para mayor ansiedad y menor bienestar psicológico, lo que compromete su aprendizaje, calidad de vida y futuro ejercicio profesional.


Asunto(s)
Ansiedad/epidemiología , Salud Mental/estadística & datos numéricos , Estudiantes de Medicina/psicología , Rendimiento Académico , Estudios Transversales , Femenino , Humanos , Modelos Logísticos , Masculino , México/epidemiología , Pruebas Psicológicas , Religión y Psicología , Factores Sexuales , Estudiantes de Medicina/estadística & datos numéricos , Adulto Joven
11.
Glob Chang Biol ; 25(10): 3516-3527, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31293015

RESUMEN

The global increase in the proportion of land cultivated with pollinator-dependent crops implies increased reliance on pollination services. Yet agricultural practices themselves can profoundly affect pollinator supply and pollination. Extensive monocultures are associated with a limited pollinator supply and reduced pollination, whereas agricultural diversification can enhance both. Therefore, areas where agricultural diversity has increased, or at least been maintained, may better sustain high and more stable productivity of pollinator-dependent crops. Given that >80% of all crops depend, to varying extents, on insect pollination, a global increase in agricultural pollinator dependence over recent decades might have led to a concomitant increase in agricultural diversification. We evaluated whether an increase in the area of pollinator-dependent crops has indeed been associated with an increase in agricultural diversity, measured here as crop diversity, at the global, regional, and country scales for the period 1961-2016. Globally, results show a relatively weak and decelerating rise in agricultural diversity over time that was largely decoupled from the strong and continually increasing trend in agricultural dependency on pollinators. At regional and country levels, there was no consistent relationship between temporal changes in pollinator dependence and crop diversification. Instead, our results show heterogeneous responses in which increasing pollinator dependence for some countries and regions has been associated with either an increase or a decrease in agricultural diversity. Particularly worrisome is a rapid expansion of pollinator-dependent oilseed crops in several countries of the Americas and Asia that has resulted in a decrease in agricultural diversity. In these regions, reliance on pollinators is increasing, yet agricultural practices that undermine pollination services are expanding. Our analysis has thereby identified world regions of particular concern where environmentally damaging practices associated with large-scale, industrial agriculture threaten key ecosystem services that underlie productivity, in addition to other benefits provided by biodiversity.


Asunto(s)
Agricultura , Ecosistema , Animales , Asia , Productos Agrícolas , Polinización
12.
Graefes Arch Clin Exp Ophthalmol ; 257(11): 2381-2390, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31451909

RESUMEN

PURPOSE: The purpose of this study is to evaluate the predictive capacity of the baseline hyperreflective dots (HRDs) on the functional and anatomical response in patients with diabetic macular edema (DME). Additionally, we assessed the impact of the intravitreal dexamethasone (DEX) implant on the functional and anatomic outcomes. METHODS: Retrospective, multicenter study. The number of HRDs was graded in four different stages: [A] none HRDs; [B] few, 1-10 HRDs; [C] moderate, 11-20 HRDs; and [D] many, ≥ 21 HRDs. For statistical purposes, groups A and B were combined [scarce HRDs (S-HRDs)] and group D was renamed as [abundant HRDs (A-HRDs)]. The primary endpoints were the mean change in best corrected visual acuity (BCVA) and central macular thickness (CMT) according to baseline HRD stage. RESULTS: One hundred eyes from one hundred patients were included in the study. Mean BCVA significantly improved from 52.9 (50.0 to 55.8) letters ETDRS at baseline to 57.2 (54.0 to 60.4) letters at month 6, p = 0.0039. There were no significant differences between the S-HRDs and A-HRD study groups in BCVA. As compared to baseline, CMT reduction was 106.3 (59.8 to 152.7) µm and 94.2 (34.7 to 153.7) µm in S-HRDs and A-HRD groups, respectively (p < 0.0001 each, respectively). Twenty-three (65.7%) and 18 (62.1%) eyes achieved a CMT reduction ≥ 10% in the S-HRD and A-HRD groups, respectively, p = 0.7640. DEX implant significantly reduced the presence of outer nuclear layer (ONL) disruptions (p = 0.0010). CONCLUSIONS: The number of HRDs did not influence either functional or anatomic outcomes. DEX implant significantly decreases the number of eyes with ONL disruptions, which might improve retinal integrity.


Asunto(s)
Dexametasona/administración & dosificación , Retinopatía Diabética/tratamiento farmacológico , Mácula Lútea/patología , Edema Macular/tratamiento farmacológico , Tomografía de Coherencia Óptica/métodos , Agudeza Visual , Anciano , Retinopatía Diabética/complicaciones , Retinopatía Diabética/diagnóstico , Implantes de Medicamentos , Femenino , Estudios de Seguimiento , Glucocorticoides/administración & dosificación , Humanos , Inyecciones Intravítreas , Edema Macular/diagnóstico , Edema Macular/etiología , Masculino , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
13.
Ecol Appl ; 28(5): 1215-1222, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29575300

RESUMEN

Globally, agriculture increasingly depends on pollinators to produce many seed and fruit crops. However, what constitutes optimal pollination service for pollinator-dependent crops remains unanswered. We developed a simulation model to identify the optimal pollination service that maximizes fruit quality in crops. The model depicts the pollination (i.e., autonomous self-fertilization, pollen deposition) and post-pollination (i.e., pollen germination, and time from germination to ovule fertilization) processes leading to fruit and seed set and allows for negative flower-pollinator interactions, specifically pistil damage. We parameterized and validated the model based on empirical observations of commercial raspberry in western Argentina. To assess the effects of pollination intensity for fruit production, we conducted simulations over a range of visit number per flower by the two primary managed pollinators worldwide, Apis mellifera and Bombus terrestris. Simulations identified that ~15-35 visits per flower by A. mellifera or ~10-20 visits by B. terrestris provide adequate pollination and maximize raspberry fruit quality (i.e., estimated as the proportion of ovules that develop into drupelets). Visits in excess of these optima reduce simulated fruit quality, and flowers receiving >670 honey bee visits or >470 bumble bee visits would produce fruits of poorer quality than those receiving no bee visits. The simulations generated consistent, unbiased predictions of fruit quality for 12 raspberry fields. This model could be adapted easily to other animal-pollinated crops and used to guide efficient pollinator management in any agro-ecosystem.


Asunto(s)
Abejas/fisiología , Análisis Costo-Beneficio , Calidad de los Alimentos , Polinización , Rubus/fisiología , Animales , Argentina , Frutas/crecimiento & desarrollo , Frutas/fisiología , Modelos Biológicos , Rubus/crecimiento & desarrollo
14.
Proc Biol Sci ; 284(1859)2017 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-28724728

RESUMEN

Conservation biology can profit greatly from incorporating a phylogenetic perspective into analyses of patterns and drivers of species extinction risk. We applied such an approach to analyse patterns of bumblebee (Bombus) decline. We assembled a database representing approximately 43% of the circa 260 globally known species, which included species extinction risk assessments following the International Union fo Conservation of Nature Red List categories and criteria, and information on species traits presumably associated with bumblebee decline. We quantified the strength of phylogenetic signal in decline, range size, tongue length and parasite presence. Overall, about one-third of the assessed bumblebees are declining and declining species are not randomly distributed across the Bombus phylogeny. Susceptible species were over-represented in the subgenus Thoracobombus (approx. 64%) and under-represented in the subgenus Pyrobombus (approx. 6%). Phylogenetic logistic regressions revealed that species with small geographical ranges and those in which none of three internal parasites were reported (i.e. Crithidia bombi, Nosema spp. or Locustacarus buchneri) were particularly vulnerable. Bumblebee evolutionary history will be deeply eroded if most species from threatened clades, particularly those stemming from basal nodes, become finally extinct. The habitat of species with restricted distribution should be protected and the importance of pathogen tolerance/resistance as mechanisms to deal with pathogens needs urgent research.


Asunto(s)
Abejas/clasificación , Abejas/microbiología , Extinción Biológica , Filogenia , Animales , Crithidia/patogenicidad , Ecosistema , Incidencia , Nosema/patogenicidad
15.
Nanomedicine ; 13(3): 1089-1094, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-27789259

RESUMEN

PEGylated nanoparticles have been extensively investigated in different platforms for drug delivery. However, the physiological effects related to platelet activation, and the potential procoagulant activity which could lead to thrombosis and further cardiovascular diseases have not been widely examined. In this work, we studied the effect of differentially charged PEGylated lipid-polymer nanoparticles in the human platelet aggregation and activation by light transmission aggregometry and flow cytometry. PEGylated nanoparticles inhibited the platelet aggregation with a dose dependency (350, 700, and 1400µg/mL) in both ADP- and collagen-induced platelet aggregation, and P-selectin expression. Charged nanoparticles (anionic and cationic) presented higher inhibitions of the platelet aggregation compared to neutral nanoparticles, and particularly the cationic particles generated a slightly higher effect. The obtained results demonstrated the safety of the differentially charged PEGylated lipid-polymer nanoparticles, and their ability to inhibit the aggregation and activation of human platelets stimulated by two classic platelet activators.


Asunto(s)
Plaquetas/efectos de los fármacos , Portadores de Fármacos/farmacología , Lípidos/farmacología , Nanopartículas/química , Inhibidores de Agregación Plaquetaria/farmacología , Polietilenglicoles/farmacología , Plaquetas/citología , Portadores de Fármacos/efectos adversos , Portadores de Fármacos/química , Humanos , Lípidos/efectos adversos , Lípidos/química , Nanopartículas/efectos adversos , Activación Plaquetaria/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/efectos adversos , Inhibidores de Agregación Plaquetaria/química , Polietilenglicoles/efectos adversos , Polietilenglicoles/química
16.
Gastroenterol Hepatol ; 40(6): 388-394, 2017.
Artículo en Inglés, Español | MEDLINE | ID: mdl-28359548

RESUMEN

Nonalcoholic steatohepatitis (NASH) is the most aggressive form of nonalcoholic fatty liver disease (NAFLD) and involves the risk of progression to more advanced stages of liver disease. Non-invasive methods are needed to identify patients with NASH. OBJECTIVE: To evaluate the diagnostic performance of the determination of serum levels of cytokeratin-18 (CK-18) as a non-invasive marker of NASH in the Chilean population. METHODS: Serum CK-18 levels were determined in a group of 41 patients with biopsy-proven NAFLD. NASH diagnosis was based on Brunt's criteria (histological parameters and ballooning), and the NAFLD activity score (NAS) and the presence of fibrosis were determined. The correlation between the NAFLD activity score (NAS) and CK-18 was evaluated with Spearman's rank correlation coefficient. A ROC curve was produced to assess the diagnostic value of CK-18 for NASH. The NAFLD fibrosis score (NFS) (to predict fibrosis and NASH) was compared to CK-18 with simple linear regression. Data were expressed in median [25th-75th percentile] and evaluated with the Wilcoxon rank test. RESULTS: The mean age of the study group (23% male) was 50.4±11.1 years. 34.2% were diagnosed with NASH (NAS≥5). CK-18 levels were significantly higher in patients with NASH versus those without NASH (183.6 IU/l [97.4 to 734.4] vs. 117.2 IU/l [83.8 to 954.8], p= 0.016). CK-18 levels were a good predictor of NASH on biopsy with an area under the curve (AUC) of 0.732 (95% CI, 0.572 to 0.897). A CK-18 cut-off of 130.5 IU/l had a sensitivity of 92.9%, specificity of 63%, positive predictive value of 56.5% and negative predictive value of 94.4%, and was able to correctly classify 73.2% of patients with NASH. NFS identified advanced liver fibrosis (AUC 0.739, 95% CI, 0.56-0.91), but was of limited value to identify NASH (AUC 0.413, 95% CI, 0.21-0.61). CONCLUSION: CK-18 is a good non-invasive marker for NASH. Although NFS was found to be an accurate marker of advanced liver fibrosis, it was not of value to identify NASH. In patients with NAFLD, CK-18 and NFS could be useful in predicting NASH and liver fibrosis, respectively.


Asunto(s)
Queratina-18/sangre , Enfermedad del Hígado Graso no Alcohólico/sangre , Adulto , Biomarcadores/sangre , Biopsia , Chile/epidemiología , Femenino , Humanos , Cirrosis Hepática/epidemiología , Cirrosis Hepática/etiología , Cirrosis Hepática/patología , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Enfermedad del Hígado Graso no Alcohólico/patología , Fragmentos de Péptidos/sangre , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad
17.
Langmuir ; 31(24): 6639-48, 2015 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-26057588

RESUMEN

Patchy polymeric particles have anisotropic surface domains that can be remarkably useful in diverse medical and industrial fields because of their ability to simultaneously present two different surface chemistries on the same construct. In this article, we report the mechanisms involved in the formation of novel lipid-polymeric hollow patchy particles during their synthesis. By cross-sectioning the patchy particles, we found that a phase segregation phenomenon occurs between the core, shell, and patch. Importantly, we found that the shear stress that the polymer blend undergoes during the particle synthesis is the most important parameter for the formation of these patchy particles. In addition, we found that the interplay of solvent-solvent, polymer-solvent, and polymer-polymer-solvent interactions generates particles with different surface morphologies. Understanding the mechanisms involved in the formation of patchy particles allows us to have a better control on their physicochemical properties. Therefore, these fundamental studies are critical to achieve batch control and scalability, which are essential aspects that must be addressed in any type of particle synthesis to be safely used in medicine.


Asunto(s)
Materiales Biocompatibles/síntesis química , Lípidos/química , Polímeros/síntesis química , Materiales Biocompatibles/química , Tamaño de la Partícula , Polímeros/química , Porosidad , Solventes/química , Propiedades de Superficie
18.
Molecules ; 20(4): 5698-713, 2015 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-25838172

RESUMEN

Berry fruit consumption has become important in the promotion of human health, mainly due to their phenolic compounds, which have been associated with protection against different pathologies, as well as antimicrobial and other biological activities. Consequently, there has been a growing interest in identifying natural antioxidants and antimicrobials from these plants. This study aimed to characterize the phenolic chemical composition and anthocyanin profile of murta (Ugni molinae Turcz.) fruit, and to evaluate the antioxidant and antimicrobial activity of its extracts (ethanolic and methanolic). LC/MS of the ethanolic extracts showed the presence of three major compounds: caffeic acid 3-glu, quercetin-3-glu and quercetin, while in the methanolic acid extract they were cyanidin-3-glucoside, pelargonidin-3-arabinose and delphinidin-3-glucoside. The antioxidant activity of ethanolic extracts (DPPH· and ORAC assays) was higher than that of methanol acid extracts or purified anthocynins. Furthermore, the methanol acid extract showed an inhibitory activity against the bacteria E. coli and S. typhi similar to that of standard antibiotics. The results suggest that the antioxidant activity of the ethanolic extract is regulated by the high content of phenolic compounds and the fruit's characteristic color is due to the content of pelargonidin-3-arabinose and delphinidin-3-glucoside. The obtained results demonstrated the appreciable antioxidant and antibacterial activities, providing opportunities to explore murta extracts as biopreservatives.


Asunto(s)
Antioxidantes/aislamiento & purificación , Fenoles/aislamiento & purificación , Extractos Vegetales/química , Antocianinas/química , Antocianinas/aislamiento & purificación , Antioxidantes/química , Antioxidantes/farmacología , Escherichia coli/efectos de los fármacos , Frutas/química , Glucósidos/química , Glucósidos/aislamiento & purificación , Humanos , Myrtaceae/química , Fenoles/química , Fenoles/farmacología , Extractos Vegetales/farmacología
19.
Artículo en Inglés | MEDLINE | ID: mdl-37706362

RESUMEN

The efforts to use novel nanotechnologies in medicine and cancer have been widespread. In order to understand better the focus areas of cancer nanomedicine research to date, we conducted a survey of nanomedicine developmental and clinical research in conjunction with treatment of various cancers. The survey has been performed based on number of publications, rate of citations, entry into clinical trials, and funding rates by the National Cancer Institute. Our survey indicates that breast and brain cancers are the most and one of the least studied by nanotechnology researchers, respectively. Breast cancer nano-therapies seem to also be most likely to achieve clinical translation as the number of publications produced, amount of funding, total citations, and clinical trials (active and completed) are the highest when compared with research in other cancers. Brain cancer, despite its low survival, has capture much less attention of nanomedicine research community as survey indicated, although nanotechnology can offer novel approaches which can address brain cancer challenges. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.


Asunto(s)
Neoplasias Encefálicas , Nanopartículas , Neoplasias , Estados Unidos , Humanos , Nanomedicina , Nanopartículas/uso terapéutico , Neoplasias/tratamiento farmacológico , Nanotecnología , Neoplasias Encefálicas/tratamiento farmacológico , National Cancer Institute (U.S.) , Sistemas de Liberación de Medicamentos
20.
Genome Biol Evol ; 16(7)2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38973368

RESUMEN

This article describes a genome assembly and annotation for Bombus dahlbomii, the giant Patagonian bumble bee. DNA from a single, haploid male collected in Argentina was used for PacBio (HiFi) sequencing, and Hi-C technology was then used to map chromatin contacts. Using Juicer and manual curation, the genome was scaffolded into 18 main pseudomolecules, representing a high-quality, near chromosome-level assembly. The sequenced genome size is estimated at 265 Mb. The genome was annotated based on RNA sequencing data of another male from Argentina, and BRAKER3 produced 15,767 annotated genes. The genome and annotation show high completeness, with >95% BUSCO scores for both the genome and annotated genes (based on conserved genes from Hymenoptera). This genome provides a valuable resource for studying the biology of this iconic and endangered species, as well as for understanding the impacts of its decline and designing strategies for its preservation.


Asunto(s)
Especies en Peligro de Extinción , Genoma de los Insectos , Anotación de Secuencia Molecular , Animales , Abejas/genética , Masculino , Cromosomas de Insectos/genética
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