Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 120(44): e2306177120, 2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37871210

RESUMEN

Lepidopterans affect crop production worldwide. The use of transgenes encoding insecticidal proteins from Bacillus thuringiensis (Bt) in crop plants is a well-established technology that enhances protection against lepidopteran larvae. Concern about widespread field-evolved resistance to Bt proteins has highlighted an urgent need for new insecticidal proteins with different modes or sites of action. We discovered a new family of insecticidal proteins from ferns. The prototype protein from Pteris species (Order Polypodiales) and variants from two other orders of ferns, Schizaeales and Ophioglossales, were effective against important lepidopteran pests of maize and soybean in diet-based assays. Transgenic maize and soybean plants producing these proteins were more resistant to insect damage than controls. We report here the crystal structure of a variant of the prototype protein to 1.98 Å resolution. Remarkably, despite being derived from plants, the structure resembles the 3-domain Cry proteins from Bt but has only two out of three of their characteristic domains, lacking the C-terminal domain which is typically required for their activities. Two of the fern proteins were effective against strains of fall armyworm that were resistant to Bt 3-domain Cry proteins Cry1Fa or Cry2A.127. This therefore represents a novel family of insecticidal proteins that have the potential to provide future tools for pest control.


Asunto(s)
Bacillus thuringiensis , Helechos , Insecticidas , Tracheophyta , Animales , Insecticidas/metabolismo , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Control Biológico de Vectores , Endotoxinas/genética , Endotoxinas/metabolismo , Proteínas Hemolisinas/genética , Proteínas Hemolisinas/metabolismo , Tracheophyta/metabolismo , Zea mays/metabolismo
2.
J Pathol ; 260(4): 376-389, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37230111

RESUMEN

The suggestion that the systemic immune response in lymph nodes (LNs) conveys prognostic value for triple-negative breast cancer (TNBC) patients has not previously been investigated in large cohorts. We used a deep learning (DL) framework to quantify morphological features in haematoxylin and eosin-stained LNs on digitised whole slide images. From 345 breast cancer patients, 5,228 axillary LNs, cancer-free and involved, were assessed. Generalisable multiscale DL frameworks were developed to capture and quantify germinal centres (GCs) and sinuses. Cox regression proportional hazard models tested the association between smuLymphNet-captured GC and sinus quantifications and distant metastasis-free survival (DMFS). smuLymphNet achieved a Dice coefficient of 0.86 and 0.74 for capturing GCs and sinuses, respectively, and was comparable to an interpathologist Dice coefficient of 0.66 (GC) and 0.60 (sinus). smuLymphNet-captured sinuses were increased in LNs harbouring GCs (p < 0.001). smuLymphNet-captured GCs retained clinical relevance in LN-positive TNBC patients whose cancer-free LNs had on average ≥2 GCs, had longer DMFS (hazard ratio [HR] = 0.28, p = 0.02) and extended GCs' prognostic value to LN-negative TNBC patients (HR = 0.14, p = 0.002). Enlarged smuLymphNet-captured sinuses in involved LNs were associated with superior DMFS in LN-positive TNBC patients in a cohort from Guy's Hospital (multivariate HR = 0.39, p = 0.039) and with distant recurrence-free survival in 95 LN-positive TNBC patients of the Dutch-N4plus trial (HR = 0.44, p = 0.024). Heuristic scoring of subcapsular sinuses in LNs of LN-positive Tianjin TNBC patients (n = 85) cross-validated the association of enlarged sinuses with shorter DMFS (involved LNs: HR = 0.33, p = 0.029 and cancer-free LNs: HR = 0.21 p = 0.01). Morphological LN features reflective of cancer-associated responses are robustly quantifiable by smuLymphNet. Our findings further strengthen the value of assessment of LN properties beyond the detection of metastatic deposits for prognostication of TNBC patients. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Asunto(s)
Aprendizaje Profundo , Neoplasias de la Mama Triple Negativas , Humanos , Ganglios Linfáticos/patología , Metástasis Linfática/patología , Estadificación de Neoplasias , Pronóstico , Estudios Retrospectivos , Neoplasias de la Mama Triple Negativas/terapia , Neoplasias de la Mama Triple Negativas/patología , Femenino , Ensayos Clínicos como Asunto
3.
Am J Occup Ther ; 78(2)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38574185

RESUMEN

The articles in this Special Issue on Recovery of Function After Neurological Injury include an impressive range of clinical diagnoses, scientific approaches, and theoretical frameworks that demonstrate the breadth and depth of occupational therapy in the restoration of function after neurological injury. An emerging theme throughout is the need for the profession of occupational therapy to identify and use more efficient methods for diagnosing and treating people with neurological injuries to improve their quality of life and the impact of care.


Asunto(s)
Terapia Ocupacional , Calidad de Vida , Humanos , Recuperación de la Función
4.
Am J Occup Ther ; 78(2)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38634670

RESUMEN

IMPORTANCE: Current interventions are limited in improving use of the more-affected upper limb in real-world daily occupations and functional independence poststroke. A comprehensive understanding of the factors influencing real-world upper limb use is required to develop interventions to improve functional independence poststroke. OBJECTIVE: To systematically review the factors that influence real-world use of the more-affected upper limb poststroke. DATA SOURCES: We searched MEDLINE, Embase, PsycINFO, and the Physiotherapy Evidence Database for English-language articles from 2012 to 2023. STUDY SELECTION AND DATA COLLECTION: Of 774 studies, we included 33 studies that had participants at least age 18 yr who exhibited upper limb impairments poststroke, objectively measured real-world upper limb use using a movement sensor, and measured factors affecting upper limb use. Two reviewers independently screened the abstracts. FINDINGS: The results were categorized by International Classification of Functioning, Disability and Health domains. Prominent factors were upper limb impairment; motor ability; functional independence; task type; hand dominance; stroke-related factors, including time since stroke; and perception of use of the more-affected upper limb. CONCLUSIONS AND RELEVANCE: Existing interventions primarily focus on upper limb impairments and motor ability. Our findings suggest that interventions should also incorporate other factors: task type (unilateral vs. bilateral), hand dominance, self-efficacy, and perception of more-affected limb use as active ingredients in improving real-world use of the more-affected upper limb poststroke. We also provide recommendations to use behavioral activation theory in designing an occupation-focused intervention to augment self-efficacy and confidence in use of the more-affected upper limb in daily occupations. Plain-Language Summary: In order to develop interventions to improve functional independence poststroke, occupational therapy practitioners must have a comprehensive understanding of the factors that influence real-world more-affected upper limb use. The study findings provide a set of distinct factors that practitioners can target separately or in combination to improve real-world use of the more-affected upper limb poststroke.


Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Humanos , Adolescente , Rehabilitación de Accidente Cerebrovascular/métodos , Extremidad Superior , Movimiento , Modalidades de Fisioterapia
5.
Breast Cancer Res Treat ; 200(2): 225-235, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37209182

RESUMEN

PURPOSE: PAM50 profiling assigns each breast cancer to a single intrinsic subtype based on a bulk tissue sample. However, individual cancers may show evidence of admixture with an alternate subtype that could affect prognosis and treatment response. We developed a method to model subtype admixture using whole transcriptome data and associated it with tumor, molecular, and survival characteristics for Luminal A (LumA) samples. METHODS: We combined TCGA and METABRIC cohorts and obtained transcriptome, molecular, and clinical data, which yielded 11,379 gene transcripts in common and 1,178 cases assigned to LumA. We used semi-supervised non-negative matrix factorization (ssNMF) to compute the subtype admixture proportions of the four major subtypes-pLumA, pLumB, pHER2, and pBasal-for each case and measured associations with tumor characteristics, molecular features, and survival. RESULTS: Luminal A cases in the lowest versus highest quartile for pLumA transcriptomic proportion had a 27% higher prevalence of stage > 1, nearly a threefold higher prevalence of TP53 mutation, and a hazard ratio of 2.08 for overall mortality. We found positive associations between pHER2 and HER2 positivity by IHC or FISH; between pLumB and PR negativity; and between pBasal and younger age, node positivity, TP53 mutation, and EGFR expression. Predominant basal admixture, in contrast to predominant LumB or HER2 admixture, was not associated with shorter survival. CONCLUSION: Bulk sampling for genomic analyses provides an opportunity to expose intratumor heterogeneity, as reflected by subtype admixture. Our results elucidate the striking extent of diversity among LumA cancers and suggest that determining the extent and type of admixture holds promise for refining individualized therapy. LumA cancers with a high degree of basal admixture appear to have distinct biological characteristics that warrant further study.


Asunto(s)
Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/patología , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Pronóstico , Perfilación de la Expresión Génica
6.
J Pathol ; 255(3): 232-242, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34346511

RESUMEN

Deep neural networks (DNNs) that predict mutational status from H&E slides of cancers can enable inexpensive and timely precision oncology. Although expert knowledge is reliable for annotating regions informative of malignancy and other known histologic patterns (strong supervision), it is unreliable for identifying regions informative of mutational status. This poses a serious impediment to obtaining higher prognostic accuracy and discovering new knowledge of pathobiology. We used a weakly supervised learning technique to train a DNN to predict BRAF V600E mutational status, determined using DNA testing, in H&E-stained images of thyroid cancer tissue without regional annotations. Our discovery cohort was a tissue microarray of only 85 patients from a single hospital. On a large independent external cohort of 444 patients from other hospitals, the trained model gave an area under the receiver operating characteristic curve of 0.98 (95% CI 0.97-1.00), which is much higher than the previously reported results for detecting any mutation using H&E by DNNs trained using strong supervision. We also developed a visualization technique that can automatically highlight regions the DNN found most informative for predicting mutational status. Our visualization is spatially granular and highly specific in highlighting strong negative and positive regions and moves us toward explainable artificial intelligence. Using t-tests, we confirmed that the proportions of follicular or papillary histology and oncocytic cytology, as noted for each patient by a pathologist who was blinded to the mutational status, were significantly different between mutated and wildtype patients. However, based solely on these features noted by the pathologist, a logistic regression classifier gave an average area under the receiver operating characteristic curve of 0.78 in five-fold cross-validation, which is much lower than that obtained using the DNN. These results highlight the potential of weakly supervised learning for training DNN models for problems where the informative visual patterns and their locations are not known a priori. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Asunto(s)
Redes Neurales de la Computación , Proteínas Proto-Oncogénicas B-raf/genética , Neoplasias de la Tiroides/genética , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Coloración y Etiquetado
7.
J Oral Maxillofac Surg ; 78(8): 1241-1256, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32479811

RESUMEN

Several uncertainties exist regarding how we will conduct our clinical, didactic, business, and social activities as the coronavirus disease 2019 (COVID-19) global pandemic abates and social distancing guidelines are relaxed. We anticipate changes in how we interact with our patients and other providers, how patient workflow is designed, the methods used to conduct our teaching sessions, and how we perform procedures in different clinical settings. The objective of the present report is to review some of the changes to consider in the clinical and academic oral and maxillofacial surgery workflow and, allow for a smoother transition, with less risk to our patients and healthcare personnel. New infection control policies should be strictly enforced and monitored in all clinical and nonclinical settings, with an overall goal to decrease the risk of exposure and transmission. Screening for COVID-19 symptoms, testing when indicated, and establishing the epidemiologic linkage will be crucial to containing and preventing new COVID-19 cases until a vaccine or an alternate solution is available. Additionally, the shortage of essential supplies such as drugs and personal protective equipment, the design and ventilation of workspaces and waiting areas, the increase in overhead costs, and the possible absence of staff, if quarantine is necessary, must be considered. This shift in our workflow and patient care paths will likely continue in the short-term at least through 2021 or the next 12 to 24 months. Thus, we must prioritize surgery, balancing patient preferences and healthcare personnel risks. We have an opportunity now to make changes and embrace telemedicine and other collaborative virtual platforms for teaching and clinical care. It is crucial that we maintain COVID-19 awareness, proper surveillance in our microenvironments, good clinical judgment, and ethical values to continue to deliver high-quality, economical, and accessible patient care.


Asunto(s)
Infecciones por Coronavirus/epidemiología , Neumonía Viral/epidemiología , Cirugía Bucal/organización & administración , Betacoronavirus , COVID-19 , Infecciones por Coronavirus/prevención & control , Humanos , Exposición Profesional/prevención & control , Cirujanos Oromaxilofaciales , Pandemias/prevención & control , Equipo de Protección Personal , Neumonía Viral/prevención & control , SARS-CoV-2 , Flujo de Trabajo
8.
J Hand Ther ; 33(2): 180-187, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32279878

RESUMEN

STUDY DESIGN: Scoping review. INTRODUCTION: With the recent advances in technologies, interactive wearable technologies including inertial motion sensors and e-textiles are emerging in the field of rehabilitation to monitor and provide feedback and therapy remotely. PURPOSE OF THE STUDY: This review article focuses on inertial measurement unit motion sensor and e-textiles-based technologies and proposes approaches to augment these interactive wearable technologies. METHODS: We conducted a comprehensive search of relevant electronic databases (eg, PubMed, the Cumulative Index to Nursing and Allied Health Literature, Embase, PsycINFO, The Cochrane Central Register of Controlled Trial, and the Physiotherapy Evidence Database). The scoping review included all study designs. RESULTS: Currently, there are a numerous research groups and companies investigating inertial motion sensors and e-textiles-based interactive wearable technologies. However, translation of these technologies to the clinic would need further research to increase ease of use and improve clinical validity of the outcomes of these technologies. DISCUSSION: The current review discusses the limitations of the interactive wearable technologies such as, limited clinical utility, bulky equipment, difficulty in setting up equipment inertial motion sensors and e-textiles. CONCLUSION: There is tremendous potential for interactive wearable technologies in rehabilitation. With the evolution of cloud computing, interactive wearable systems can remotely provide intervention and monitor patient progress using models of telerehabilitation. This will revolutionize the delivery of rehabilitation and make rehabilitation more accessible and affordable to millions of individuals.


Asunto(s)
Electromiografía/instrumentación , Monitoreo Fisiológico/instrumentación , Movimiento (Física) , Modalidades de Fisioterapia/instrumentación , Extremidad Superior , Dispositivos Electrónicos Vestibles , Humanos
9.
BMC Cancer ; 19(1): 215, 2019 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-30849944

RESUMEN

BACKGROUND: PAM50 gene profiling assigns each cancer to a single intrinsic subtype. However, individual cancers vary in their adherence to a prototype, and due to bulk tissue sampling, some may exhibit expression patterns that indicate intra-tumor admixture of multiple subtypes. Our objective was to develop admixture metrics from PAM50 gene expression profiles in order to stratify Luminal A (LumA) cases according to their degree of subtype admixture, and then relate such admixture to clinical and molecular variables. METHODS: We re-constructed scaled, normalized PAM50 profiles for 1980 cases (674 LumA) in the METABRIC cohort and for each case computed its Mahalanobis (M-) distance from its assigned centroid and M-distance from all other centroids. We used t-SNE plots to visualize overlaps in subtype clustering. With Normal-like cases excluded, we developed two metrics: Median Distance Criteria (MDC) classified pure cases as those located within the 50th percentile of the LumA centroid and > =50th percentile from any other centroid. Distance Ratio Criteria (DRC) was computed as the ratio of M-distances from the LumA centroid to the nearest non-assigned centroid. Pure and admixed LumA cases were compared on clinical/molecular traits. TCGA LumA cases (n = 509) provided independent validation. RESULTS: Compared to pure cases in METABRIC, admixed ones had older age at diagnosis, larger tumor size, and higher grade and stage. These associations were stronger for the DRC metric compared to MDC. Admixed cases were associated with HER2 gain, high proliferation, higher PAM50 recurrence scores, more frequent TP53 mutation, and less frequent PIK3CA mutation. Similar results were observed in the TCGA validation cohort, which also showed a positive association between admixture and number of clonal populations estimated by PyClone. LumA-LumB confusion predominated, but other combinations were also present. Degree of admixture was associated with overall survival in both cohorts, as was disease-free survival in TCGA, independent of age, grade and stage (HR = 2.85, Tertile 3 vs.1). CONCLUSIONS: Luminal A breast cancers subgrouped based on PAM50 subtype purity support the hypothesis that admixed cases have worse clinical features and survival. Future analyses will explore more extensive genomic metrics for admixture and their spatial significance within a single tumor.


Asunto(s)
Biomarcadores de Tumor , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/mortalidad , Análisis por Conglomerados , Biología Computacional , Femenino , Perfilación de la Expresión Génica , Humanos , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Pronóstico , Modelos de Riesgos Proporcionales , Reproducibilidad de los Resultados , Transcriptoma , Carga Tumoral
10.
BJU Int ; 122(1): 143-151, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29461667

RESUMEN

OBJECTIVE: To determine whether a computer vision-based approach applied to haematoxylin and eosin (H&E) prostate biopsy images can distinguish dutasteride-treated tissue from placebo, and identify features associated with degree of responsiveness to 5α-reductase inhibitor (5ARI) therapy. SUBJECTS AND METHODS: Our study population comprised 100 treatment-adherent men without prostate cancer assigned to dutasteride or placebo in the REDUCE trial, who had slides available from mandatory year-4 biopsies. Half of the men also provided slides from a year-2 biopsy. We obtained 20× whole-slide images and used specialized software to generate a library of 1 300 epithelial and stromal features from objects comprising superpixels and several types of nuclei, including spatial relations among objects between and within each hierarchical level. We used penalized logistic regression and fivefold cross-validation to find optimal combinations of histological features in the year-4 biopsies. Feature data from the year-2 biopsies were fitted to a final model for independent validation. Two pathologists, blinded to treatment, scored each image for focal atrophy and histological features previously linked to 5AR1 treatment. RESULTS: Consensus classification by pathologists obtained a discrimination accuracy equivalent to chance. A 21-feature computer vision model gave a cross-validation area under the curve of 0.97 (95% confidence interval [CI] 0.95-0.99) in the year-4 biopsies and 0.79 (95% CI: 0.65-0.92) in the set-aside year-2 biopsies. Histology scores were not correlated with change in prostate-specific antigen level, serum dihydrotestosterone level or gland volume. Key features associated with dutasteride treatment included greater shape and colour uniformity in stroma, irregular clustering of epithelial nuclei, and greater variation in lumen shape. CONCLUSION: The present findings show that a computer vision approach can detect subtle histological effects attributable to dutasteride, resulting in a continuous measure of responsiveness to the drug that could eventually be used to predict individual patient response in the context of BPH treatment or cancer chemoprevention.


Asunto(s)
Inhibidores de 5-alfa-Reductasa/uso terapéutico , Diagnóstico por Computador/métodos , Dutasterida/uso terapéutico , Próstata/patología , Hiperplasia Prostática/tratamiento farmacológico , Anciano , Biopsia con Aguja/métodos , Simulación por Computador , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Patólogos , Próstata/efectos de los fármacos , Hiperplasia Prostática/patología
12.
Nephrol Dial Transplant ; 32(3): 459-465, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-27507892

RESUMEN

Background: C3 glomerulopathy (C3G) is caused by overactivity of the alternative pathway of complement that results in bright glomerular C3 staining with minimal or no deposition of immunoglobulins on immunofluorescence microscopy. Laser microdissection and mass spectrometry of the two subtypes, C3 glomerulonephritis (C3GN) and dense deposit disease (DDD), have identified C3 as the predominant glomerular complement protein, although lesser amounts of C9, C5, C6, C7 and C8 are detectable. C3 plays a central role in complement activity, with its proteolytic cleavage first generating C3a and C3b, followed by inactivation of C3b generating iC3b (which includes C3α and C3ß), which undergoes further breakdown yielding C3c and terminal breakdown fragment C3dg. The composition of C3 breakdown products in C3G is not known. Methods: In this study, we chose six cases each of C3GN and DDD to analyze the composition of C3 deposits. We analyzed the amino acid sequence of C3 spectra detected by mass spectrometry to determine the relative abundance of C3 fragments in C3G. Thus we were able to determine the amino acid sequences mapping to the various C3 activation products including C3dg, C3α (C3α1 and α2), and C3ß that are part of C3b/iC3b/C3c. Results: C3dg is the predominant cleavage product detected with the highest amino acid coverage. The remaining amino acids map to C3α (C3α1 and α2) and C3ß. Amino acids mapping to C3a and C3f are absent. Taken together, the C3α and C3ß amino acids represent iC3b prior to or after C3c cleavage of C3dg. The C3 spectra for both C3GN and DDD are surprisingly similar. Conclusion: The finding of large amounts of C3dg suggests that C3b deposition in the glomerulus is an active process triggered by thioester binding of C3b to the glycocalyx overlying the glomerular endothelial cells and glomerular basement membrane. Regulatory protein-mediated inactivation of C3b results in the generation of iC3b. After additional cleavages, mostly C3dg remains.


Asunto(s)
Complemento C3/metabolismo , Glomerulonefritis Membranoproliferativa/metabolismo , Glomerulonefritis/metabolismo , Glomérulos Renales/metabolismo , Adolescente , Adulto , Secuencia de Aminoácidos , Biopsia , Niño , Cromatografía Liquida , Complemento C3a/metabolismo , Complemento C3b/metabolismo , Femenino , Glomerulonefritis/patología , Glomerulonefritis Membranoproliferativa/patología , Humanos , Glomérulos Renales/ultraestructura , Masculino , Espectrometría de Masas , Microscopía Electrónica , Microscopía Fluorescente , Persona de Mediana Edad , Fragmentos de Péptidos/metabolismo , Adulto Joven
13.
RNA Biol ; 13(7): 656-69, 2016 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-27245473

RESUMEN

RNA interference (RNAi) has become a widely used reverse genetic tool to study gene function in eukaryotic organisms and is being developed as a technology for insect pest management. The efficiency of RNAi varies among organisms. Insects from different orders also display differential efficiency of RNAi, ranging from highly efficient (coleopterans) to very low efficient (lepidopterans). We investigated the reasons for varying RNAi efficiency between lepidopteran and coleopteran cell lines and also between the Colorado potato beetle, Leptinotarsa decemlineata and tobacco budworm, Heliothis virescens. The dsRNA either injected or fed was degraded faster in H. virescens than in L. decemlineata. Both lepidopteran and coleopteran cell lines and tissues efficiently took up the dsRNA. Interestingly, the dsRNA administered to coleopteran cell lines and tissues was taken up and processed to siRNA whereas the dsRNA was taken up by lepidopteran cell lines and tissues but no siRNA was detected in the total RNA isolated from these cell lines and tissues. The data included in this paper showed that the degradation and intracellular transport of dsRNA are the major factors responsible for reduced RNAi efficiency in lepidopteran insects.


Asunto(s)
Interferencia de ARN/fisiología , ARN Bicatenario/metabolismo , Animales , Transporte Biológico Activo/fisiología , Escarabajos , ARN Bicatenario/genética , Células Sf9 , Spodoptera
14.
J Econ Entomol ; 109(2): 982-6, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26896534

RESUMEN

Termites are highly effective digesters of wood lignocellulose, which is a central factor contributing to their global status as pests of wooden structures. For the same reason, termite baits that combine cellulosic matrices with slow-acting insecticides are both effective and popular as a reduced-risk approach for termite control. This study took a novel approach for assessing digestibility of termite bait matrices and matrix components to gain potentially new insights into bait attractiveness and efficacy. The rationale behind this study is that termite baits that are more digestible should have more nutritional value to termites and thus encourage maximal feeding and trophallactic transfer of active ingredients through termite colonies. Studies were done using in vitro digestion assays with termite gut protein extracts followed by colorimetric detection of released glucose and pentose monosaccharides from test substrates. The substrates tested included two commercial bait matrices (Recruit IV and Recruit II HD), two matrix components (compressed and toasted compressed cellulose), and two natural pine woods as positive controls (southern yellow and northern pine). Overall results show equal or greater monosaccharide availability for some commercial matrices than standard pine lignocelluloses, suggesting sufficient nutritional value for the proprietary matrices. Another more prominent trend was significant intercolony variation in digestibility across substrates, possibly resulting from differences in microbiota composition, long-term diet adaptation, or both. These findings thus illuminate new nutrition-based factors that can potentially impact bait feeding, trophallactic exchange, and efficacy.


Asunto(s)
Celulosa/metabolismo , Digestión , Control de Insectos/instrumentación , Isópteros/metabolismo , Animales , Glucosa/análisis , Pentosas/análisis
15.
J Stroke Cerebrovasc Dis ; 25(1): 129-35, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26456199

RESUMEN

OBJECTIVES: The primary objective of this paper was to determine whether heart rate variability (HRV) acquired upon admission to inpatient rehabilitation is associated with motor outcome 3 months after stroke. The secondary objective of this paper was to determine whether HRV shows a strong association with the motor outcome 3 months after stroke in individuals with severe initial motor impairments. METHODS: We recruited 13 patients with acute stroke from an acute inpatient rehabilitation hospital. A Holter monitor was placed upon admission and Fugl-Meyer Upper Extremity and Lower Extremity Subscales were used to assess the movement of the affected upper and lower extremities 3 months after admission. The standard deviation of R-R intervals was used to quantify HRV. RESULTS: A Spearman rank correlation revealed a strong positive and significant correlation between HRV upon admission and movement of the affected upper extremity (r = .70, P = .01) and affected lower extremity (r = .60, P = .03) at 3 months. For patients with severe initial motor impairments, HRV showed a strong positive association with the movement of the affected upper (r = .61, P = .04) and lower (r = .70, P = .04) extremities at 3 months. CONCLUSION: HRV is strongly associated with motor outcome after stroke and provides a promising marker to explore the mechanisms associated with motor recovery after stroke.


Asunto(s)
Frecuencia Cardíaca/fisiología , Trastornos del Movimiento/etiología , Accidente Cerebrovascular/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Brazo/fisiopatología , Sistema Nervioso Autónomo/fisiopatología , Comorbilidad , Electrocardiografía Ambulatoria , Femenino , Humanos , Pacientes Internos , Pierna/fisiopatología , Masculino , Persona de Mediana Edad , Trastornos del Movimiento/fisiopatología , Trastornos del Movimiento/rehabilitación , Recuperación de la Función , Centros de Rehabilitación , Índice de Severidad de la Enfermedad , Rehabilitación de Accidente Cerebrovascular , Resultado del Tratamiento
17.
Artículo en Inglés | MEDLINE | ID: mdl-38607772

RESUMEN

Background: Previous research has shown that noninvasive brain stimulation can be used to study how the central nervous system (CNS) prepares the execution of a motor task. However, these previous studies have been limited to a single muscle or single degree of freedom movements (e.g., wrist flexion). It is currently unclear if the findings of these studies generalize to multi-joint movements involving multiple muscles, which may be influenced by kinematic redundancy and muscle synergies. Objective: The objective of this study was to characterize corticospinal excitability during motor preparation in the cortex prior to functional upper extremity reaches. Methods: 20 participants without neurological impairments volunteered for this study. During the experiment, the participants reached for a cup in response to a visual "Go Cue". Prior to movement onset, we used transcranial magnetic stimulation (TMS) to stimulate the motor cortex and measured the changes in motor evoked potentials (MEPs) in several upper extremity muscles. We varied each participant's initial arm posture and used a novel synergy-based MEP analysis to examine the effect of muscle coordination on MEPs. Additionally, we varied the timing of the stimulation between the Go Cue and movement onset to examine the time course of motor preparation. Results: We found that synergies with strong proximal muscle (shoulder and elbow) components emerged as the stimulation was delivered closer to movement onset, regardless of arm posture, but MEPs in the distal (wrist and finger) muscles were not facilitated. We also found that synergies varied with arm posture in a manner that reflected the muscle coordination of the reach. Conclusions: We believe that these findings provide useful insight into the way the CNS plans motor skills.

18.
J Dent Educ ; 88(3): 289-294, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38044476

RESUMEN

PURPOSE: The aims of this study were to estimate the type and frequency of different medical emergencies that occurred over the study period (twelve years) and discuss the lessons learned and the modifications made in the curriculum to better equip dental students and faculty in their management. MATERIALS AND METHODS: A retrospective study was conducted to evaluate all medical emergencies that needed activation of the response team at our school from 2008 to 2020. RESULTS: The emergency response system was activated 250 times during the 12-year period. There were 132 medical emergencies in the pre-doctoral clinic and 105 events in the post-doctoral clinic (p 0.0680). Most of the emergencies occurred in patients between 45 and 64 years of age. Syncope occurs most often followed by adverse cardiovascular, respiratory, anxiety, and hypoglycemic events. CONCLUSIONS: Medical emergencies occurring in a dental school provide a unique opportunity for students to gain experience in their management. The key lies in preparing the students and faculty to prevent them from occurring, but should these occur, then they should be able to promptly recognize symptoms and institute prompt intervention.


Asunto(s)
Urgencias Médicas , Tratamiento de Urgencia , Humanos , Estudios Retrospectivos , Facultades de Odontología , Instituciones Académicas
19.
Arch Insect Biochem Physiol ; 84(4): 175-93, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24186432

RESUMEN

Termites and their gut microbial symbionts efficiently degrade lignocellulose into fermentable monosaccharides. This study examined three glycosyl hydrolase family 7 (GHF7) cellulases from protist symbionts of the termite Reticulitermes flavipes. We tested the hypotheses that three GHF7 cellulases (GHF7-3, GHF7-5, and GHF7-6) can function synergistically with three host digestive enzymes and a fungal cellulase preparation. Full-length cDNA sequences of the three GHF7s were assembled and their protist origins confirmed through a combination of quantitative PCR and cellobiohydrolase (CBH) activity assays. Recombinant versions of the three GHF7s were generated using a baculovirus-insect expression system and their activity toward several model substrates compared with and without metallic cofactors. GHF7-3 was the most active of the three cellulases; it exhibited a combination of CBH, endoglucanase (EGase), and ß-glucosidase activities that were optimal around pH 7 and 30°C, and enhanced by calcium chloride and zinc sulfate. Lignocellulose saccharification assays were then done using various combinations of the three GHF7s along with a host EGase (Cell-1), beta-glucosidase (ß-glu), and laccase (LacA). GHF7-3 was the only GHF7 to enhance glucose release by Cell-1 and ß-glu. Finally, GHF7-3, Cell-1, and ß-glu were individually tested with a commercial fungal cellulase preparation in lignocellulose saccharification assays, but only ß-glu appreciably enhanced glucose release. Our hypothesis that protist GHF7 cellulases are capable of synergistic interactions with host termite digestive enzymes is supported only in the case of GHF7-3. These findings suggest that not all protist cellulases will enhance saccharification by cocktails of other termite or fungal lignocellulases.


Asunto(s)
Celulasas/metabolismo , Eucariontes/enzimología , Isópteros/enzimología , Isópteros/parasitología , Lignina/metabolismo , Secuencia de Aminoácidos , Animales , Celulasas/química , Celulasas/genética , Eucariontes/genética , Proteínas Fúngicas/metabolismo , Tracto Gastrointestinal/enzimología , Tracto Gastrointestinal/parasitología , Regulación Enzimológica de la Expresión Génica , Datos de Secuencia Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Transcriptoma
20.
J Hand Ther ; 26(2): 132-7; quiz 138, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23084461

RESUMEN

STUDY DESIGN: Quasi-experimental design. INTRODUCTION: Although the effectiveness of constraint-induced movement therapy (CIMT) in upper extremity (UE) rehabilitation post stroke is well known, the efficacy of CIMT to enhance the temporal structure of variability in upper extremity movement is not known. PURPOSE: The purpose of this study was to investigate whether CIMT could enhance the temporal structure of variability in upper extremity movement in individuals with chronic stroke. METHODS: Six participants with chronic stroke underwent CIMT for 4 h/day for 2 weeks. Participants performed three trials of functional reach-to-grasp before and after CIMT. Temporal structure of variability was determined by calculating approximate entropy (ApEn) in shoulder, elbow and wrist flexion/extension joint angles. RESULTS: ApEn increased post CIMT, however, statistical significance was not achieved (p > 0.0167). CONCLUSION: Future studies with larger sample size are warranted to investigate the effect of CIMT upon temporal structure of variability in UE movement. LEVEL OF EVIDENCE: 4.


Asunto(s)
Hemiplejía/rehabilitación , Terapia Pasiva Continua de Movimiento/métodos , Rango del Movimiento Articular/fisiología , Rehabilitación de Accidente Cerebrovascular , Extremidad Superior/fisiopatología , Anciano , Estudios de Cohortes , Electromiografía/métodos , Femenino , Articulaciones de los Dedos/fisiopatología , Hemiplejía/etiología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Recuperación de la Función , Accidente Cerebrovascular/complicaciones , Resultado del Tratamiento , Articulación de la Muñeca/fisiopatología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA