Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
J Exp Bot ; 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38642398

RESUMEN

Plant growth depends on sugar production and export by photosynthesising source leaves and sugar allocation and import by sink tissues (grains, roots, stems, young leaves). Photosynthesis and sink demand are tightly coordinated through metabolic (substrate, allosteric) feedback and signalling (sugar, hormones) mechanisms. Sugar signalling integrates sugar production with plant development and environmental cues. In C3 plants (e.g., wheat, rice), it is well documented that sugar accumulation in source leaves, due to source-sink imbalance, negatively feedbacks on photosynthesis and plant productivity. However, we have a limited understanding about the molecular mechanisms underlying those feedback regulations, especially in C4 plants (e.g., maize, sorghum, sugarcane). Recent work with the C4 model Setaria viridis suggested that C4 leaves have different sugar sensing thresholds and behaviours relative to C3 counterparts. Addressing this research priority is critical because improving crop yield requires a better understanding of how plants coordinate source activity with sink demand. Here we review the literature, present a model of action for sugar sensing in C4 source leaves and suggest ways forward.

2.
J Am Acad Dermatol ; 90(4): 716-726, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38040338

RESUMEN

BACKGROUND: Pediatric melanoma presents with distinct clinical features compared to adult disease. OBJECTIVE: Characterize risk factors and negative outcomes in pediatric melanoma. METHODS: Multicenter retrospective study of patients under 20 years diagnosed with melanoma between January 1, 1995 and June 30, 2015 from 11 academic medical centers. RESULTS: Melanoma was diagnosed in 317 patients, 73% of whom were diagnosed in adolescence (age ≥11). Spitzoid (31%) and superficial spreading (26%) subtypes were most common and 11% of cases arose from congenital nevi. Sentinel lymph node biopsy was performed in 68% of cases and positive in 46%. Fatality was observed in 7% of cases. Adolescent patients with melanoma were more likely to have family history of melanoma (P = .046) compared to controls. LIMITATIONS: Retrospective nature, cohort size, control selection, and potential referral bias. CONCLUSION: Pediatric melanoma has diverse clinical presentations. Better understanding of these cases and outcomes may facilitate improved risk stratification of pediatric melanoma.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Adulto , Humanos , Niño , Adolescente , Melanoma/patología , Estudios Retrospectivos , Neoplasias Cutáneas/patología , Biopsia del Ganglio Linfático Centinela , Factores de Riesgo
3.
Graefes Arch Clin Exp Ophthalmol ; 262(1): 133-141, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37470808

RESUMEN

PURPOSE: Corneal scars after infectious keratitis lead to insufficient transparency and irregular astigmatism, affecting visual acuity; therefore, they should be accurately evaluated to estimate visual function. This study aimed to quantitatively evaluate corneal irregularity and scarring after infectious keratitis using anterior segment optical coherence tomography (AS-OCT). METHODS: This was an observational clinical study. We included patients who had corneal scarring after treatment of infectious keratitis between 2014 and 2021 at University of Tokyo Hospital. We retrospectively examined best spectacle-corrected visual acuity (BSCVA), average keratometric power, central corneal thickness (CCT), and four components of the Fourier harmonic analysis including spherical and asymmetry components, as well as regular astigmatism and higher-order irregularity. We included anterior and posterior corneal data and compared results with those of contralateral healthy eyes. Additionally, we quantitatively evaluated the densitometry of the cornea obtained using AS-OCT. RESULTS: A total of 122 eyes of 61 patients were examined; male predominance was observed (n = 37), and the mean patient age was 55.3 ± 19.4 years. Comparisons with contralateral healthy eyes showed that BSCVA worsened (0.30 ± 0.83 and 0.93 ± 1.36 logMAR, respectively, P = 0.003), and CCT (531.1 ± 46.2 and 591.8 ± 132.4 µm, respectively, P < 0.001) and corneal densitometry (84.4 ± 11.8 and 111.9 ± 19.2 grayscale units, respectively, P < 0.001) increased significantly in affected eyes. The asymmetry component and higher-order irregularities that were not corrected with spectacles significantly increased (both P < 0.001), and there were no significant differences in the changes among the bacterial, fungal, herpetic, and acanthamoeba types of keratitis. CONCLUSION: Corneal scarring persisted after treatment for infectious keratitis, and the asymmetry and irregularities of corneal astigmatism increased as visual acuity deteriorated. AS-OCT with the Fourier harmonic analysis was useful for evaluating corneal topographic changes in patients with corneal scarring after keratitis.


Asunto(s)
Astigmatismo , Lesiones de la Cornea , Queratitis , Humanos , Masculino , Adulto , Persona de Mediana Edad , Anciano , Femenino , Tomografía de Coherencia Óptica/métodos , Cicatriz/patología , Astigmatismo/patología , Estudios Retrospectivos , Córnea/patología , Topografía de la Córnea , Lesiones de la Cornea/patología
4.
Plant J ; 109(3): 615-632, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34780111

RESUMEN

Photosynthetic efficiency and sink demand are tightly correlated with rates of phloem loading, where maintaining low cytosolic sugar concentrations is paramount to prevent the downregulation of photosynthesis. Sugars Will Eventually be Exported Transporters (SWEETs) are thought to have a pivotal role in the apoplastic phloem loading of C4 grasses. SWEETs have not been well studied in C4 species, and their investigation is complicated by photosynthesis taking place across two cell types and, therefore, photoassimilate export can occur from either one. SWEET13 homologues in C4 grasses have been proposed to facilitate apoplastic phloem loading. Here, we provide evidence for this hypothesis using the C4 grass Setaria viridis. Expression analyses on the leaf gradient of C4 species Setaria and Sorghum bicolor show abundant transcript levels for SWEET13 homologues. Carbohydrate profiling along the Setaria leaf shows total sugar content to be significantly higher in the mature leaf tip compared with the younger tissue at the base. We present the first known immunolocalization results for SvSWEET13a and SvSWEET13b using novel isoform-specific antisera. These results show localization to the bundle sheath and phloem parenchyma cells of both minor and major veins. We further present the first transport kinetics study of C4 monocot SWEETs by using a Xenopus laevis oocyte heterologous expression system. We demonstrate that SvSWEET13a and SvSWEET13b are high-capacity transporters of glucose and sucrose, with a higher apparent Vmax for sucrose, compared with glucose, typical of clade III SWEETs. Collectively, these results provide evidence for an apoplastic phloem loading pathway in Setaria and possibly other C4 species.


Asunto(s)
Transporte Biológico/genética , Glucosa/metabolismo , Proteínas de Transporte de Monosacáridos/metabolismo , Floema/metabolismo , Setaria (Planta)/genética , Setaria (Planta)/metabolismo , Sacarosa/metabolismo , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Fotosíntesis , Transcripción Genética
5.
J Exp Bot ; 74(10): 2968-2986, 2023 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-36883216

RESUMEN

In the developing seeds of all higher plants, filial cells are symplastically isolated from the maternal tissue supplying photosynthate to the reproductive structure. Photoassimilates must be transported apoplastically, crossing several membrane barriers, a process facilitated by sugar transporters. Sugars Will Eventually be Exported Transporters (SWEETs) have been proposed to play a crucial role in apoplastic sugar transport during phloem unloading and the post-phloem pathway in sink tissues. Evidence for this is presented here for developing seeds of the C4 model grass Setaria viridis. Using immunolocalization, SvSWEET4 was detected in various maternal and filial tissues within the seed along the sugar transport pathway, in the vascular parenchyma of the pedicel, and in the xylem parenchyma of the stem. Expression of SvSWEET4a in Xenopus laevis oocytes indicated that it functions as a high-capacity glucose and sucrose transporter. Carbohydrate and transcriptional profiling of Setaria seed heads showed that there were some developmental shifts in hexose and sucrose content and consistent expression of SvSWEET4 homologues. Collectively, these results provide evidence for the involvement of SWEETs in the apoplastic transport pathway of sink tissues and allow a pathway for post-phloem sugar transport into the seed to be proposed.


Asunto(s)
Setaria (Planta) , Azúcares , Azúcares/metabolismo , Setaria (Planta)/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Floema/metabolismo , Transporte Biológico , Proteínas de Transporte de Membrana/metabolismo , Sacarosa/metabolismo
6.
Ann Bot ; 131(6): 985-1000, 2023 07 10.
Artículo en Inglés | MEDLINE | ID: mdl-37103118

RESUMEN

BACKGROUND AND AIMS: The mechanisms of sugar sensing in grasses remain elusive, especially those using C4 photosynthesis even though a large proportion of the world's agricultural crops utilize this pathway. We addressed this gap by comparing the expression of genes encoding components of sugar sensors in C3 and C4 grasses, with a focus on source tissues of C4 grasses. Given C4 plants evolved into a two-cell carbon fixation system, it was hypothesized this may have also changed how sugars were sensed. METHODS: For six C3 and eight C4 grasses, putative sugar sensor genes were identified for target of rapamycin (TOR), SNF1-related kinase 1 (SnRK1), hexokinase (HXK) and those involved in the metabolism of the sugar sensing metabolite trehalose-6-phosphate (T6P) using publicly available RNA deep sequencing data. For several of these grasses, expression was compared in three ways: source (leaf) versus sink (seed), along the gradient of the leaf, and bundle sheath versus mesophyll cells. KEY RESULTS: No positive selection of codons associated with the evolution of C4 photosynthesis was identified in sugar sensor proteins here. Expressions of genes encoding sugar sensors were relatively ubiquitous between source and sink tissues as well as along the leaf gradient of both C4 and C3 grasses. Across C4 grasses, SnRK1ß1 and TPS1 were preferentially expressed in the mesophyll and bundle sheath cells, respectively. Species-specific differences of gene expression between the two cell types were also apparent. CONCLUSIONS: This comprehensive transcriptomic study provides an initial foundation for elucidating sugar-sensing genes within major C4 and C3 crops. This study provides some evidence that C4 and C3 grasses do not differ in how sugars are sensed. While sugar sensor gene expression has a degree of stability along the leaf, there are some contrasts between the mesophyll and bundle sheath cells.


Asunto(s)
Magnoliopsida , Poaceae , Poaceae/genética , Poaceae/metabolismo , Azúcares/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Fotosíntesis/genética
7.
Lasers Surg Med ; 54(1): 157-169, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34412154

RESUMEN

OBJECTIVES: Minimally invasive fat sculpting techniques are becoming more widespread with the development of office-based devices and therapies. Electrochemical lipolysis (ECLL) is a needle-based technology that uses direct current (DC) to electrolyze tissue water creating acid and base in situ. In turn, fat is saponified and adipocyte cell membrane lysis occurs. The electrolysis of water can be accomplished using a simple open-loop circuit (V-ECLL) or by incorporating a feedback control circuit using a potentiostat (P-ECLL). A potentiostat utilizes an operational amplifier with negative feedback to allow users to precisely control voltage at specific electrodes. To date, the variation between the two approaches has not been studied. The aim of this study was to assess current and charge transfer variation and lipolytic effect created by the two approaches in an in vivo porcine model. METHODS: Charge transfer measurements from ex vivo V-ECLL and P-ECLL treated porcine skin and fat were recorded at -1 V P-ECLL, -2 V P-ECLL, -3 V P-ECLL, and -5 V V-ECLL each for 5 min to guide dosimetry parameters for in vivo studies. In follow-up in vivo studies, a sedated female Yorkshire pig was treated with both V-ECLL and P-ECLL across the dorsal surface over a range of dosimetry parameters, including -1.5 V P-ECLL, -2.5 V P-ECLL, -3.5 V P-ECLL, and 5 V V-ECLL each treated for 5 min. Serial biopsies were performed at baseline before treatment, 1, 2, 7, 14, and 28 days after treatment. Tissue was examined using fluorescence microscopy and histology to compare the effects of the two ECLL approaches. RESULTS: Both V-ECLL and P-ECLL treatments induced in-vivo fat necrosis evident by adipocyte membrane lysis, adipocyte denuclearization, and an acute inflammatory response across a 28-day longitudinal study. However, -1.5 V P-ECLL produced a smaller spatial necrotic effect compared to 5 V V-ECLL. In addition, 5 V V-ECLL produced a comparable necrotic effect to that of -2.5 V and -3.5 V P-ECLL. CONCLUSIONS: V-ECLL and P-ECLL at the aforementioned dosimetry parameters both achieved fat necrosis by adipocyte membrane lysis and denuclearization. The -2.5 V and -3.5 V P-ECLL treatments created spatially similar fat necrotic effects when compared to the 5 V V-ECLL treatment. Quantitatively, total charge transfer between dosimetry parameters suggests that -2.5 V P-ECLL and 5 V V-ECLL produce comparable electrochemical reactions. Such findings suggest that a low-voltage closed-loop potentiostat-based system is capable of inducing fat necrosis to a similar extent compared to that of a higher voltage direct current system.


Asunto(s)
Adipocitos , Lipólisis , Animales , Estudios de Factibilidad , Retroalimentación , Femenino , Estudios Longitudinales , Porcinos
8.
Health Promot Pract ; 23(1): 174-184, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-32713213

RESUMEN

Introduction. The success of family-based community programs for childhood obesity may be increased by promoting social-cognitive factors that influence motivation and participant engagement. Incentivizing behavior can potentially enhance engagement and encourage behavior change. This research investigated motivators to engagement with a multicomponent incentive-based strategy to improve attendance and health-related behavior change in a family community-based weight management program for overweight and obese children. Method. Qualitative analysis combining; demographic data (n = 512), survey of parents (n = 273), and stakeholder (n = 10) and family interviews (n = 24). Participants were selected from program providers and families participating in an Australian community weight management program during a randomized controlled trial (n = 512 children). Maximum variation sampling (demographics and group characteristics) and inductive thematic analysis were used. Results/Conclusion. Four factors influencing engagement were (1) personal value, (2) achievement, (3) support, and (4) overwhelm. These themes corroborated with social-cognitive factors, fostered by a combination of behavior change components in the program that increased participant accountability and intrinsic motivation. Focusing on autonomous goal planning with parental involvement, tracking of goals, and reviewing of goals may complement existing strategies in child-focused treatment programs. Low-value noncash incentives linked to goal setting for encouraging healthy eating and physical activity were well accepted and may enhance family engagement and attendance.


Asunto(s)
Sobrepeso , Obesidad Infantil , Australia , Niño , Humanos , Motivación , Sobrepeso/psicología , Sobrepeso/terapia , Padres/psicología , Obesidad Infantil/prevención & control
9.
Microb Pathog ; 161(Pt A): 105271, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34728370

RESUMEN

Group B Streptococcus (GBS) is an opportunistic pathogen found in the vaginal tract and is a leading cause of preterm birth and neonatal illness. Aside from GBS, the vaginal tract is predominantly colonized by commensal Lactobacillus species that are thought to protect the vaginal tract from pathogens, including GBS. Studies that examined if, and how Lactobacilli modulate GBS pathogenicity remain limited. This study sought to investigate the potential protective role of Lactobacillus rhamnosus against GBS, using an in vitro model system. Immunofluorescence microscopy and Scanning Electron Microscopy (SEM) captured images of infected HeLa cells and were analyzed using the image analysis program ImageJ. Results indicate that GBS causes HeLa cell detachment unless L. rhamnosus is present. SEM images show that GBS reduces length and number of microvilli on HeLa cell surface, as well as size of secreted vesicles. L. rhamnosus partially inhibits GBS-dependent microvilli and vesicle disruption. GBS also disrupts HeLa cell F-actin fibers unless L. rhamnosus is present. These results reveal effects of GBS infection on the host cell cytoskeleton and implies a protective role of L. rhamnosus against GBS colonization.


Asunto(s)
Lacticaseibacillus rhamnosus , Nacimiento Prematuro , Infecciones Estreptocócicas , Femenino , Células HeLa , Humanos , Recién Nacido , Streptococcus agalactiae , Vagina
10.
Catheter Cardiovasc Interv ; 98(5): 1000-1005, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-33002282

RESUMEN

Endomyocardial biopsy (EMB) is a common procedure used to aid in the diagnosis of diffuse myocardial diseases and, less commonly, in the diagnosis of cardiac tumors. As cardiac tumors are often found in high-risk locations (ventricular free wall or atria), precision biopsy is paramount, and additional imaging, like transesophageal echocardiography is often required for guidance. The use of intracardiac echocardiography (ICE) to guide biopsy has been described, but there is no consensus on a standardized approach. We report our institutional approach with three cases of ICE-directed EMB performed with the 2.4 mm Jawz bioptome directed with an 8.5-Fr Agilis NxT steerable introducer. All cases were performed under guidance with the AcuNav ICE probe. There were no procedural complications and a definitive diagnosis was obtained in all three cases. We also review the available published cases of ICE-guided EMB in the literature-noting the different procedural approaches, complication rate, and diagnostic yield. There were only two negative biopsies reported among the published cases and no reported complications. Our review of all these cases suggests that ICE-guidance for EMB is superior to other forms of imaging in its ease of use and high definition of right-sided cardiac structures. We also feel that the use of the Agilis steerable sheath allows for more precise directing of the bioptome and is a critical component in performing a successful targeted biopsy.


Asunto(s)
Cardiomiopatías , Ventrículos Cardíacos , Biopsia , Cateterismo Cardíaco , Ecocardiografía , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Resultado del Tratamiento
11.
Surg Innov ; 28(6): 776-779, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33629890

RESUMEN

Need. Battery-powered Light Emitting Diode (LED) surgical headlights are necessary for improved intraoperative illumination but may be costly. Technical Solution. The objective of this study was to develop a low-cost surgical headlight using a consumer-grade LED headlight and 3D-printed mount. Proof of Concept. Eighteen surgical residents performed simulation exercises that mimicked suturing in the oral cavity using both a custom prototype headlight and a commercial surgical headlight. The time required to complete the task with each headlight was recorded along with an exit survey. A second device was created based on the critiques of the first device and was tested by ten additional surgical trainees. Surgical residents completed the simulation task in 27 ± 8.6 seconds and 21 ± 5.6 seconds with the commercially available headlight and first prototype, respectively. In the second experiment, the simulation task was completed in 23 ± 11.1 and 23 ± 12.2 seconds with the commercially available headlight and second device, respectively. Survey results showed an overall positive consensus, with critiques about headband security, suggestions for smaller LED chassis, and a more robust mounting bracket. Some preferred the prototype headlight due to the wider field of illumination compared to the commercially available unit (ie, beam spread/beam angle). Next Steps. Future adjustments are required to optimize the location of the headlight and the battery to modify the weight distribution of the device. Conclusion. These findings demonstrate that our prototype models are viable alternatives to conventional surgical headlights and warrant continued optimization for broader adoption by surgeons and trainees for whom higher-cost alternatives are not an option.


Asunto(s)
Iluminación , Cirujanos , Análisis Costo-Beneficio , Humanos , Impresión Tridimensional
12.
Proc Natl Acad Sci U S A ; 114(12): 3085-3090, 2017 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-28265087

RESUMEN

Active-learning pedagogies have been repeatedly demonstrated to produce superior learning gains with large effect sizes compared with lecture-based pedagogies. Shifting large numbers of college science, technology, engineering, and mathematics (STEM) faculty to include any active learning in their teaching may retain and more effectively educate far more students than having a few faculty completely transform their teaching, but the extent to which STEM faculty are changing their teaching methods is unclear. Here, we describe the development and application of the machine-learning-derived algorithm Decibel Analysis for Research in Teaching (DART), which can analyze thousands of hours of STEM course audio recordings quickly, with minimal costs, and without need for human observers. DART analyzes the volume and variance of classroom recordings to predict the quantity of time spent on single voice (e.g., lecture), multiple voice (e.g., pair discussion), and no voice (e.g., clicker question thinking) activities. Applying DART to 1,486 recordings of class sessions from 67 courses, a total of 1,720 h of audio, revealed varied patterns of lecture (single voice) and nonlecture activity (multiple and no voice) use. We also found that there was significantly more use of multiple and no voice strategies in courses for STEM majors compared with courses for non-STEM majors, indicating that DART can be used to compare teaching strategies in different types of courses. Therefore, DART has the potential to systematically inventory the presence of active learning with ∼90% accuracy across thousands of courses in diverse settings with minimal effort.


Asunto(s)
Aprendizaje Basado en Problemas/normas , Ciencia/educación , Enseñanza/normas , Humanos , Sonido , Estudiantes , Tecnología , Universidades/normas
13.
J Pediatr ; 211: 152-158, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31103258

RESUMEN

OBJECTIVE: To identify risk factors associated with nonmelanoma skin cancer (NMSC) occurrence and survival in children. STUDY DESIGN: This was a multicenter, retrospective, case-control study of patients <20 years of age diagnosed with NMSC between 1995 and 2015 from 11 academic medical centers. The primary outcome measure was frequency of cases and controls with predisposing genetic conditions and/or iatrogenic exposures, including chemotherapy, radiation, systemic immunosuppression, and voriconazole. RESULTS: Of the 124 children with NMSC (40 with basal cell carcinoma, 90 with squamous cell carcinoma), 70% had at least 1 identifiable risk factor. Forty-four percent of the cases had a predisposing genetic condition or skin lesion, and 29% had 1 or more iatrogenic exposures of prolonged immunosuppression, radiation therapy, chemotherapy, and/or voriconazole use. Prolonged immunosuppression and voriconazole use were associated with squamous cell carcinoma occurrence (cases vs controls; 30% vs 0%, P = .0002, and 15% vs 0%, P = .03, respectively), and radiation therapy and chemotherapy were associated with basal cell carcinoma occurrence (both 20% vs 1%, P < .0001). Forty-eight percent of initial skin cancers had been present for >12 months prior to diagnosis and 49% of patients were diagnosed with ≥2 skin cancers. At last follow-up, 5% (6 of 124) of patients with NMSC died. Voriconazole exposure was noted in 7 cases and associated with worse 3-year overall survival (P = .001). CONCLUSIONS: NMSC in children and young adults is often associated with a predisposing condition or iatrogenic exposure. High-risk patients should be identified early to provide appropriate counseling and management.


Asunto(s)
Carcinoma Basocelular/epidemiología , Carcinoma de Células Escamosas/epidemiología , Neoplasias Cutáneas/epidemiología , Adolescente , Antifúngicos/efectos adversos , Antineoplásicos/efectos adversos , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Predisposición Genética a la Enfermedad/epidemiología , Humanos , Inmunosupresores/efectos adversos , Lactante , Masculino , Radioterapia/efectos adversos , Estudios Retrospectivos , Factores de Riesgo , Estados Unidos/epidemiología , Voriconazol/efectos adversos , Adulto Joven
14.
Catheter Cardiovasc Interv ; 94(1): 165-170, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-30588751

RESUMEN

OBJECTIVES: This study investigates the correlation of occlusive wedge pressure (WP) with direct left atrial (LA) pressure in patients with severe mitral regurgitation (MR) undergoing transcatheter mitral valve repair (TMVr) with MitraClip. BACKGROUND: There is interest in acquiring objective hemodynamic parameters for intraprocedural guidance in patients undergoing MitraClip. METHODS: The study included 94 patients with severe MR at prohibitive surgical risk who underwent MitraClip at the University of California Davis Medical Center between 2014 and 2016. RESULTS: An average of 1.8 ± 0.7 clips were used to achieve MR grade of 2+ or less in 99% of patients. Correlation analysis of all (n = 236) pre-clip, inter-clip, and final-clip WP and LA pressures yielded a Pearson's R (r) of 0.85 and 0.79 for mean WP vs mean LA and WP V vs LA V, respectively. Median LA V to mean LA ratio (LAV:mLA) was 1.75 (IQR 1.5-1.9). 79% (n = 74) of patients had LAV:mLA ratio ≥ 1.5 with associated WP V vs LA V correlation (r) of 0.83. In patients with LAV:mLA ratio < 1.5, the correlation (r) was 0.69. Baseline characteristics were not significantly different between patients with LAV:mLA ratio ≥ 1.5 and patients with LAV:mLA ratio < 1.5. Post-procedure, median LA V: mean LA ratio decreased from 1.75 to 1.4, P = 0.0001. CONCLUSIONS: Correlation between WP and direct LA pressure in patients with severe MR undergoing Mitraclip is modest. Caution is advised when using WP to approximate LA pressure intraprocedurally, especially in patients with baseline low LAV:mLA ratios.


Asunto(s)
Función del Atrio Izquierdo , Presión Atrial , Cateterismo Cardíaco , Implantación de Prótesis de Válvulas Cardíacas , Insuficiencia de la Válvula Mitral/cirugía , Válvula Mitral/cirugía , Monitoreo Intraoperatorio , Presión Esfenoidal Pulmonar , Anciano , Anciano de 80 o más Años , Cateterismo Cardíaco/efectos adversos , Cateterismo Cardíaco/instrumentación , Femenino , Prótesis Valvulares Cardíacas , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/instrumentación , Humanos , Masculino , Válvula Mitral/diagnóstico por imagen , Válvula Mitral/fisiopatología , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/fisiopatología , Diseño de Prótesis , Sistema de Registros , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Factores de Tiempo , Resultado del Tratamiento
15.
Lasers Surg Med ; 51(5): 412-422, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30681167

RESUMEN

OBJECTIVES: There have been many advancements in laryngeal imaging using optical coherence tomography (OCT), with varying system design and probes for use in research, office, and operating room settings. We evaluated the performance of six distinct OCT systems in imaging porcine vocal folds (cords) using computational image processing and segmentation. METHODS: Porcine vocal folds were scanned using six OCT systems. Imaging system and probe performance were quantitatively assessed for signal penetration, layer differentiation, and epithelium (EP) measurement. Fitted exponential decay curves with corresponding α constant and intensity thresholding segmentation were utilized to quantify the aforementioned parameters. RESULTS: The smallest average α constant and deepest signal penetration was of the SS-OCT 1700 nm 90 kHz microscope system (α = -1.74), followed by the SS-OCT 1310 nm 200 kHz VCSEL microscope system (α = -1.99), and SS-OCT 1310 nm 50 kHz rigid forward viewing endoscope system (α = -2.23). The EP was not readily visualized for three out of six systems, but was detected using automated segmentation. Average EP thickness (mean ± SD) was calculated as 55.79 ± 31.86 µm which agrees favorably with previous literature. CONCLUSION: Comparisons of OCT systems are challenging, as they encompass different probe design, optical path, and lasers, depending on application. Practical evaluation of different systems using computer based quantitative image processing and segmentation revealed basic, constructive information, such as EP measurements. To further validate the comparisons of system performance with clinical usability, in vivo human laryngeal imaging will be conducted. Further development of automated image processing and segmentation can be useful in rapid analysis of information. Lasers Surg. Med. 51:412-422, 2019. © 2019 Wiley Periodicals, Inc.

17.
Pediatr Dermatol ; 35(6): e402-e403, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30216522

RESUMEN

We present a 3-year-old boy with Langerhans cell histiocytosis who developed granulomatous dermatitis while taking vemurafenib. Vemurafenib currently has Food and Drug Administration approval for the treatment of BRAF V600E+ metastatic melanoma in adults, but recent discoveries of BRAF V600E in more than half of tested Langerhans cell histiocytosis lesions have prompted clinical trials of vemurafenib therapy for children with refractory, multisystem Langerhans cell histiocytosis. This report contributes to the knowledge of its potential side effects when used in children.


Asunto(s)
Antineoplásicos/efectos adversos , Erupciones por Medicamentos/diagnóstico , Histiocitosis de Células de Langerhans/tratamiento farmacológico , Indoles/efectos adversos , Sulfonamidas/efectos adversos , Preescolar , Erupciones por Medicamentos/tratamiento farmacológico , Erupciones por Medicamentos/etiología , Glucocorticoides/uso terapéutico , Granuloma/etiología , Humanos , Masculino , Piel/patología , Triamcinolona/uso terapéutico , Vemurafenib
18.
Angew Chem Int Ed Engl ; 55(3): 917-21, 2016 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-26756442

RESUMEN

A chemosensory system is reported that operates without the need for separation techniques and is capable of identifying anions and structurally similar bioactive molecules. In this strategy, the coordination of analytes to a metal complex with an open binding cleft generates "static structures" on the NMR timescale. Unique signals are created by strategically placing fluorine atoms in close proximity to bound analytes so that small structural differences induce distinct (19)F NMR shifts that can be used to identify each analyte. The utility of this method is illustrated by quantifying caffeine levels in coffee, by identifying ingredients in tea and energy drinks, and by discriminating between multiple biogenic amines with remote structural differences six carbon atoms away from the binding site. We further demonstrate the simultaneous identification of multiple neutral and anionic species in a complex mixture.


Asunto(s)
Aniones/análisis , Mezclas Complejas/química , Espectroscopía de Resonancia Magnética
19.
Artículo en Inglés | MEDLINE | ID: mdl-26958435

RESUMEN

This report summarizes study results on pairing-based cryptography. The main purpose of the study is to form NIST's position on standardizing and recommending pairing-based cryptography schemes currently published in research literature and standardized in other standard bodies. The report reviews the mathematical background of pairings. This includes topics such as pairing-friendly elliptic curves and how to compute various pairings. It includes a brief introduction to existing identity-based encryption (IBE) schemes and other cryptographic schemes using pairing technology. The report provides a complete study of the current status of standard activities on pairing-based cryptographic schemes. It explores different application scenarios for pairing-based cryptography schemes. As an important aspect of adopting pairing-based schemes, the report also considers the challenges inherent in validation testing of cryptographic algorithms and modules. Based on the study, the report suggests an approach for including pairing-based cryptography schemes in the NIST cryptographic toolkit. The report also outlines several questions that will require further study if this approach is followed.

20.
Cochrane Database Syst Rev ; (10): CD009701, 2014 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-25300173

RESUMEN

BACKGROUND: When women require induction of labour, oxytocin is the most common agent used, delivered by an intravenous infusion titrated to uterine contraction strength and frequency. There is debate over the optimum dose regimen and how it impacts on maternal and fetal outcomes, particularly induction to birth interval, mode of birth, and rates of hyperstimulation. Current induction of labour regimens include both high- and low-dose regimens and are delivered by either continuous or pulsed infusions, with both linear and non-linear incremental increases in oxytocin dose. Whilst low-dose protocols bring on contractions safely, their potentially slow induction to birth interval may increase the chance of fetal infection and chorioamnionitis. Conversely, high-dose protocols may cause undue uterine hyperstimulation and fetal distress. OBJECTIVES: To determine the effectiveness and safety of high- versus low-dose oxytocin for induction of labour at term SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2014) and the reference lists of relevant papers. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised controlled trials that compared oxytocin protocol for induction of labour for women at term, where high-dose oxytocin is at least 100 mU oxytocin in the first 40 minutes, with increments delivering at least 600 mU in the first two hours, compared with low-dose oxytocin, defined as less than 100 mU oxytocin in the first 40 minutes, and increments delivering less than 600 mU total in the first two hours. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study eligibility, extracted data and assessed the risk of bias of included studies. Data were checked for accuracy. MAIN RESULTS: We have included nine trials, involving 2391 women and their babies in this review. Trials were at a moderate to high risk of bias overall.Results of primary outcomes revealed no significant differences in rates of vaginal delivery not achieved within 24 hours (risk ratio (RR) 0.94, 95% confidence interval (CI) 0.78 to 1.14, two trials, 1339 women) or caesarean section (RR 0.96, 95% CI 0.81 to 1.14, eight trials, 2023 women). There was no difference in serious maternal morbidity or death (RR 1.24, 95% CI 0.55 to 2.82, one trial, 523 women), and no difference in serious neonatal morbidity or perinatal death (RR 0.84, 95% CI 0.23 to 3.12, one trial, 781 infants). Finally, no trials reported on the number of women who had uterine hyperstimulation with fetal heart rate changes.Results of secondary outcomes revealed no difference between time from induction to delivery (mean difference (MD) -0.90 hours, 95% CI -2.28 to +0.49 hours; five studies), uterine rupture (RR 3.10, 95% CI 0.50 to 19.33; three trials), epidural analgesia (RR 1.03, 95% CI 0.89 to 1.18; two trials), instrumental birth (RR 1.22, 95% CI 0.88 to 1.66; three trials), Apgar less than seven at five minutes (RR 1.25, 95% CI 0.77 to 2.01, five trials), perinatal death (RR 0.84, 95% CI 0.23 to 3.12; two trials), postpartum haemorrhage (RR 1.08, 95% CI 0.87 to 1.34; five trials), or endometritis (RR 1.35, 95% CI 0.53 to 3.43; three trials). Removal of high bias studies reveals a significant reduction of induction to delivery interval (MD -1.94 hours, 95% CI -0.99 to -2.89 hours, 489 women). A significant increase in hyperstimulation without specifying fetal heart rate changes was found in the high-dose group (RR 1.86, 95% CI 1.55 to 2.25).No other secondary outcomes were reported: unchanged/unfavourable cervix after 12 to 24 hours, meconium-stained liquor, neonatal intensive care unit admission, neonatal encephalopathy, disability in childhood, other maternal side-effects (nausea, vomiting, diarrhoea), maternal antibiotic use, maternal satisfaction, neonatal infection and neonatal antibiotic use. AUTHORS' CONCLUSIONS: The findings of our review do not provide evidence that high-dose oxytocin increases either vaginal delivery within 24 hours or the caesarean section rate. There is no significant decrease in induction to delivery time at meta-analysis but these results may be confounded by poor quality trials. High-dose oxytocin was shown to increase the rate of uterine hyperstimulation but the effects of this are not clear. The conclusions here are specific to the definitions used in this review. Further trials evaluating the effects of high-dose regimens of oxytocin for induction of labour should consider all important maternal and infant outcomes.


Asunto(s)
Trabajo de Parto Inducido/métodos , Oxitócicos/administración & dosificación , Oxitocina/administración & dosificación , Nacimiento a Término , Femenino , Humanos , Oxitócicos/efectos adversos , Oxitocina/efectos adversos , Embarazo , Ensayos Clínicos Controlados Aleatorios como Asunto
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA