Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 731
Filtrar
1.
J Eur Acad Dermatol Venereol ; 38(5): 954-966, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38279594

RESUMEN

BACKGROUND: Primary cutaneous B-cell lymphomas (CBCL) are a group of rare malignant skin diseases that represent approximately 20%-30% of all primary cutaneous lymphomas (PCL). Previous studies revealed impaired health-related quality of life (HRQoL) in patients diagnosed with primary cutaneous T-cell lymphoma (CTCL). Currently, only small-sized studies investigated HRQoL in CBCL patients and lacked detailed analysis of respective subtypes. OBJECTIVES: This study aims to investigate HRQoL in CBCL patients to identify independent factors of HRQoL impairment in CBCL patients. METHODS: One hundred CBCL patients were recruited from eight German PCL centres in this multicentric, cross-sectional study from 2021 to 2022. The patients completed the dermatologic HRQoL questionnaire Skindex-29 and an investigator-designed 'CBCL-Questionnaire' with additional questions on HRQoL and clinical characteristics. RESULTS: The Skindex-29 revealed that HRQoL in CBCL patients is impaired on a mild to moderate level. The multiple regression analysis identified parameters like worries about dying, feeling prejudiced/discriminated and impairment of daily activities to be independently associated with impairment of HRQoL. Highest scores for HRQoL impairment were found in patients with primary cutaneous follicle centre lymphoma while on rituximab treatment and in patients with primary cutaneous marginal zone lymphoma while on watchful waiting. CONCLUSIONS: HRQoL is impaired in CBCL patients, even though, in the face of indolent disease course and favourable prognosis in the majority of cases. Of note, our investigator-designed tool identified worries about dying, feeling prejudiced/discriminated, and the type of treatment to have a negative impact on patients' HRQoL. Our study highlights the importance of a thorough patient-doctor communication to capture overall disease burden because generic HRQoL tools might lack of disease-specific items.


Asunto(s)
Linfoma de Células B , Calidad de Vida , Neoplasias Cutáneas , Humanos , Masculino , Neoplasias Cutáneas/psicología , Neoplasias Cutáneas/patología , Femenino , Estudios Transversales , Persona de Mediana Edad , Anciano , Linfoma de Células B/psicología , Adulto , Encuestas y Cuestionarios , Anciano de 80 o más Años , Actividades Cotidianas
2.
Artículo en Inglés | MEDLINE | ID: mdl-37937146

RESUMEN

Purpose: Cone-beam CT (CBCT) is widespread in abdominal interventional imaging, but its long acquisition time makes it susceptible to patient motion. Image-based autofocus has shown success in CBCT deformable motion compensation, via deep autofocus metrics and multi-region optimization, but it is challenged by the large parameter dimensionality required to capture intricate motion trajectories. This work leverages the differentiable nature of deep autofocus metrics to build a novel optimization strategy, Multi-Stage Adaptive Spine Autofocus (MASA), for compensation of complex deformable motion in abdominal CBCT. Methods: MASA poses the autofocus problem as a multi-stage adaptive sampling strategy of the motion trajectory, sampled with Hermite spline basis with variable amplitude and knot temporal positioning. The adaptive method permits simultaneous optimization of the sampling phase, local temporal sampling density, and time-dependent amplitude of the motion trajectory. The optimization is performed in a multi-stage schedule with increasing number of knots that progressively accommodates complex trajectories in late stages, preconditioned by coarser components from early stages, and with minimal increase in dimensionality. MASA was evaluated in controlled simulation experiments with two types of motion trajectories: i) combinations of slow drifts with sudden jerk (sigmoid) motion; and ii) combinations of periodic motion sources of varying frequency into multi-frequency trajectories. Further validation was obtained in clinical data from liver CBCT featuring motion of contrast-enhanced vessels, and soft-tissue structures. Results: The adaptive sampling strategy provided successful motion compensation in sigmoid trajectories, compared to fixed sampling strategies (mean SSIM increase of 0.026 compared to 0.011). Inspection of the estimated motion showed the capability of MASA to automatically allocate larger sampling density to parts of the scan timeline featuring sudden motion, effectively accommodating complex motion without increasing the problem dimension. Experiments on multi-frequency trajectories with 3-stage MASA (5, 10, and 15 knots) yielded a twofold SSIM increase compared to single-stage autofocus with 15 knots (0.076 vs 0.040, respectively). Application of MASA to clinical datasets resulted in simultaneous improvement on the delineation of both contrast-enhanced vessels and soft-tissue structures in the liver. Conclusion: A new autofocus framework, MASA, was developed including a novel multi-stage technique for adaptive temporal sampling of the motion trajectory in combination with fully differentiable deep autofocus metrics. This novel adaptive sampling approach is a crucial step for application of deformable motion compensation to complex temporal motion trajectories.

3.
Langenbecks Arch Surg ; 408(1): 202, 2023 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-37209306

RESUMEN

PURPOSE: Postoperative wound complications are common in patients undergoing resection of lower extremity soft tissue tumors. Postoperative drainage therapy ensures adequate wound healing but may delay or complicate it. The aim of this study is to evaluate the incidence of postoperative wound complications and delayed or prolonged drainage treatment and to propose a standardized definition and severity grading of complex postoperative courses. METHODS: A monocentric retrospective analysis of 80 patients who had undergone primary resection of lower extremity soft tissue tumors was performed. A new classification was developed, which takes into account postoperative drainage characteristics and wound complications. Based on this classification, risk factors and the prognostic value of daily drainage volumes were evaluated. RESULTS: According to this new definition, regular postoperative course grade 0 (no wound complication and timely drainage removal) occurred in 26 patients (32.5%), grade A (minor wound complications or delayed drainage removal) in 12 (15.0%), grade B (major wound complication or prolonged drainage therapy) in 31 (38.8%), and grade C (reoperation) in 11 (13.7%) patients. Tumor-specific characteristics, such as tumor size (p = 0.0004), proximal tumor location (p = 0.0484), and tumor depth (p = 0.0138) were identified as risk factors for complex postoperative courses (grades B and C). Drainage volume on postoperative day 4 was a suitable predictor for complex courses (cutoff of 70 ml/d). CONCLUSION: The proposed definition incorporates wound complications and drainage management while also being clinically relevant and easy to apply. It may serve as a standardized endpoint for assessing the postoperative course after resection of lower extremity soft tissue tumors.


Asunto(s)
Sarcoma , Neoplasias de los Tejidos Blandos , Humanos , Estudios Retrospectivos , Radioterapia Adyuvante/efectos adversos , Sarcoma/patología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/terapia , Extremidad Inferior/cirugía , Neoplasias de los Tejidos Blandos/cirugía , Neoplasias de los Tejidos Blandos/patología , Drenaje/efectos adversos
4.
Artículo en Inglés | MEDLINE | ID: mdl-36381251

RESUMEN

Cone-beam CT (CBCT) is widely used for guidance in interventional radiology but it is susceptible to motion artifacts. Motion in interventional CBCT features a complex combination of diverse sources including quasi-periodic, consistent motion patterns such as respiratory motion, and aperiodic, quasi-random, motion such as peristalsis. Recent developments in image-based motion compensation methods include approaches that combine autofocus techniques with deep learning models for extraction of image features pertinent to CBCT motion. Training of such deep autofocus models requires the generation of large amounts of realistic, motion-corrupted CBCT. Previous works on motion simulation were mostly focused on quasi-periodic motion patterns, and reliable simulation of complex combined motion with quasi-random components remains an unaddressed challenge. This work presents a framework aimed at synthesis of realistic motion trajectories for simulation of deformable motion in soft-tissue CBCT. The approach leveraged the capability of conditional generative adversarial network (GAN) models to learn the complex underlying motion present in unlabeled, motion-corrupted, CBCT volumes. The approach is designed for training with unpaired clinical CBCT in an unsupervised fashion. This work presents a first feasibility study, in which the model was trained with simulated data featuring known motion, providing a controlled scenario for validation of the proposed approach prior to extension to clinical data. Our proof-of-concept study illustrated the potential of the model to generate realistic, variable simulation of CBCT deformable motion fields, consistent with three trends underlying the designed training data: i) the synthetic motion induced only diffeomorphic deformations - with Jacobian Determinant larger than zero; ii) the synthetic motion showed median displacement of 0. 5 mm in regions predominantly static in the training (e.g., the posterior aspect of the patient laying supine), compared to a median displacement of 3.8 mm in regions more prone to motion in the training; and iii) the synthetic motion exhibited predominant directionality consistent with the training set, resulting in larger motion in the superior-inferior direction (median and maximum amplitude of 4.58 mm and 20 mm, > 2x larger than the two remaining direction). Together, the proposed framework shows the feasibility for realistic motion simulation and synthesis of variable CBCT data.

5.
Artículo en Inglés | MEDLINE | ID: mdl-36381250

RESUMEN

Deformable motion is one of the main challenges to image quality in interventional cone beam CT (CBCT). Autofocus methods have been successfully applied for deformable motion compensation in CBCT, using multi-region joint optimization approaches that leverage the moderately smooth spatial variation motion of the deformable motion field with a local neighborhood. However, conventional autofocus metrics enforce images featuring sharp image-appearance, but do not guarantee the preservation of anatomical structures. Our previous work (DL-VIF) showed that deep convolutional neural networks (CNNs) can reproduce metrics of structural similarity (visual information fidelity - VIF), removing the need for a matched motion-free reference, and providing quantification of motion degradation and structural integrity. Application of DL-VIF within local neighborhoods is challenged by the large variability of local image content across a CBCT volume, and requires global context information for successful evaluation of motion effects. In this work, we propose a novel deep autofocus metric, based on a context-aware, multi-resolution, deep CNN design. In addition to the inclusion of contextual information, the resulting metric generates a voxel-wise distribution of reference-free VIF values. The new metric, denoted CADL-VIF, was trained on simulated CBCT abdomen scans with deformable motion at random locations and with amplitude up to 30 mm. The CADL-VIF achieved good correlation with the ground truth VIF map across all test cases with R2 = 0.843 and slope = 0.941. When integrated into a multi-ROI deformable motion compensation method, CADL-VIF consistently reduced motion artifacts, yielding an average increase in SSIM of 0.129 in regions with severe motion and 0.113 in regions with mild motion. This work demonstrated the capability of CADL-VIF to recognize anatomical structures and penalize unrealistic images, which is a key step in developing reliable autofocus for complex deformable motion compensation in CBCT.

6.
Artículo en Inglés | MEDLINE | ID: mdl-36381563

RESUMEN

Purpose: Cone-beam CT has become commonplace for 3D guidance in interventional radiology (IR), especially for vascular procedures in which identification of small vascular structures is crucial. However, its long image acquisition time poses a limit to image quality due to soft-tissue deformable motion that hampers visibility of small vessels. Autofocus motion compensation has shown promising potential for soft-tissue deformable motion compensation, but it lacks specific target to the imaging task. This work presents an approach for deformable motion compensation targeted at imaging of vascular structures. Methods: The proposed method consists on a two-stage framework for: i) identification of contrast-enhanced blood vessels in 2D projection data and delineation of an approximate region covering the vascular target in the volume space, and, ii) a novel autofocus approach including a metric designed to promote the presence of vascular structures acting solely in the region of interest. The vesselness of the image is quantified via evaluation of the properties of the 3D image Hessian, yielding a vesselness filter that gives larger values to voxels candidate to be part of a tubular structure. A cost metric is designed to promote large vesselness values and spatial sparsity, as expected in regions of fine vascularity. A targeted autofocus method was designed by combining the presented metric with a conventional autofocus term acting outside of the region of interest. The resulting method was evaluated on simulated data including synthetic vascularity merged with real anatomical features obtained from MDCT data. Further evaluation was obtained in two clinical datasets obtained during TACE procedures with a robotic C-arm (Artis Zeego, Siemens Healthineers). Results: The targeted vascular autofocus effectively restored the shape and contrast of the contrast-enhanced vascularity in the simulation cases, resulting in improved visibility and reduced artifacts. Segmentations performed with a single threshold value on the target vascular regions yielded a net increase of up to 42% in DICE coefficient computed against the static reference. Motion compensation in clinical datasets resulted in improved visibility of vascular structures, observed in maximum intensity projections of the contrast-enhanced liver vessel tree. Conclusion: Targeted motion compensation for vascular imaging showed promising performance for increased identification of small vascular structures in presence of motion. The development of autofocus metrics and methods tailored to vascular imaging opens the way for reliable compensation of deformable motion while preserving the integrity of anatomical structures in the image.

7.
Phys Med Biol ; 67(12)2022 06 16.
Artículo en Inglés | MEDLINE | ID: mdl-35636391

RESUMEN

Purpose. Patient motion artifacts present a prevalent challenge to image quality in interventional cone-beam CT (CBCT). We propose a novel reference-free similarity metric (DL-VIF) that leverages the capability of deep convolutional neural networks (CNN) to learn features associated with motion artifacts within realistic anatomical features. DL-VIF aims to address shortcomings of conventional metrics of motion-induced image quality degradation that favor characteristics associated with motion-free images, such as sharpness or piecewise constancy, but lack any awareness of the underlying anatomy, potentially promoting images depicting unrealistic image content. DL-VIF was integrated in an autofocus motion compensation framework to test its performance for motion estimation in interventional CBCT.Methods. DL-VIF is a reference-free surrogate for the previously reported visual image fidelity (VIF) metric, computed against a motion-free reference, generated using a CNN trained using simulated motion-corrupted and motion-free CBCT data. Relatively shallow (2-ResBlock) and deep (3-Resblock) CNN architectures were trained and tested to assess sensitivity to motion artifacts and generalizability to unseen anatomy and motion patterns. DL-VIF was integrated into an autofocus framework for rigid motion compensation in head/brain CBCT and assessed in simulation and cadaver studies in comparison to a conventional gradient entropy metric.Results. The 2-ResBlock architecture better reflected motion severity and extrapolated to unseen data, whereas 3-ResBlock was found more susceptible to overfitting, limiting its generalizability to unseen scenarios. DL-VIF outperformed gradient entropy in simulation studies yielding average multi-resolution structural similarity index (SSIM) improvement over uncompensated image of 0.068 and 0.034, respectively, referenced to motion-free images. DL-VIF was also more robust in motion compensation, evidenced by reduced variance in SSIM for various motion patterns (σDL-VIF = 0.008 versusσgradient entropy = 0.019). Similarly, in cadaver studies, DL-VIF demonstrated superior motion compensation compared to gradient entropy (an average SSIM improvement of 0.043 (5%) versus little improvement and even degradation in SSIM, respectively) and visually improved image quality even in severely motion-corrupted images.Conclusion: The studies demonstrated the feasibility of building reference-free similarity metrics for quantification of motion-induced image quality degradation and distortion of anatomical structures in CBCT. DL-VIF provides a reliable surrogate for motion severity, penalizes unrealistic distortions, and presents a valuable new objective function for autofocus motion compensation in CBCT.


Asunto(s)
Algoritmos , Tomografía Computarizada de Haz Cónico , Artefactos , Cadáver , Tomografía Computarizada de Haz Cónico/métodos , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Movimiento (Física)
8.
Lett Appl Microbiol ; 73(3): 294-299, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34028058

RESUMEN

The hemagglutination inhibition (HI) test has long been used as a standard measure of antibody response for inactivated influenza vaccines. However, the HI test has limitations, such as insensitivity when using some H3N2 virus strains and failure to detect neutralizing antibodies that target regions distant from the receptor binding site. We therefore examined a hemagglutinin pseudovirus neutralization (PVN) test as a possible supplement or alternative to the HI test. We evaluated the association of HI or PVN titres with protection against influenza infection in mice based on morbidity (where the illness was defined as 25% body weight loss). We assessed this relationship using dose-response models incorporating HI or PVN titres as a variable. The morbidity was correlated with the pre-exposure titres, and such a correlation was well described by a modified dose-response model. The mathematical modelling suggests that PVN titres consistently show a stronger association with in vivo protection as compared to HI titres in mice. Given our findings, the PVN test warrants further investigation as a tool for evaluating antibody responses to influenza vaccines containing hemagglutinin. The resulting models may also be useful for analyzing human clinical data to identify potentially protective antibody titres against influenza illness.


Asunto(s)
Vacunas contra la Influenza , Gripe Humana , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Hemaglutinación , Glicoproteínas Hemaglutininas del Virus de la Influenza , Hemaglutininas , Humanos , Subtipo H3N2 del Virus de la Influenza A , Gripe Humana/prevención & control , Ratones
9.
Phys Med Biol ; 66(5): 055010, 2021 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-33594993

RESUMEN

Image-guided therapies in the abdomen and pelvis are often hindered by motion artifacts in cone-beam CT (CBCT) arising from complex, non-periodic, deformable organ motion during long scan times (5-30 s). We propose a deformable image-based motion compensation method to address these challenges and improve CBCT guidance. Motion compensation is achieved by selecting a set of small regions of interest in the uncompensated image to minimize a cost function consisting of an autofocus objective and spatiotemporal regularization penalties. Motion trajectories are estimated using an iterative optimization algorithm (CMA-ES) and used to interpolate a 4D spatiotemporal motion vector field. The motion-compensated image is reconstructed using a modified filtered backprojection approach. Being image-based, the method does not require additional input besides the raw CBCT projection data and system geometry that are used for image reconstruction. Experimental studies investigated: (1) various autofocus objective functions, analyzed using a digital phantom with a range of sinusoidal motion magnitude (4, 8, 12, 16, 20 mm); (2) spatiotemporal regularization, studied using a CT dataset from The Cancer Imaging Archive with deformable sinusoidal motion of variable magnitude (10, 15, 20, 25 mm); and (3) performance in complex anatomy, evaluated in cadavers undergoing simple and complex motion imaged on a CBCT-capable mobile C-arm system (Cios Spin 3D, Siemens Healthineers, Forchheim, Germany). Gradient entropy was found to be the best autofocus objective for soft-tissue CBCT, increasing structural similarity (SSIM) by 42%-92% over the range of motion magnitudes investigated. The optimal temporal regularization strength was found to vary widely (0.5-5 mm-2) over the range of motion magnitudes investigated, whereas optimal spatial regularization strength was relatively constant (0.1). In cadaver studies, deformable motion compensation was shown to improve local SSIM by ∼17% for simple motion and ∼21% for complex motion and provided strong visual improvement of motion artifacts (reduction of blurring and streaks and improved visibility of soft-tissue edges). The studies demonstrate the robustness of deformable motion compensation to a range of motion magnitudes, frequencies, and other factors (e.g. truncation and scatter).


Asunto(s)
Tomografía Computarizada de Haz Cónico , Procesamiento de Imagen Asistido por Computador/métodos , Movimientos de los Órganos , Algoritmos , Artefactos , Humanos , Fantasmas de Imagen , Factores de Tiempo
10.
Porcine Health Manag ; 7(1): 3, 2021 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-33397503

RESUMEN

BACKGROUND: Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) continues to be a major economic issue for the swine industry worldwide, not only due to acute outbreaks but also endemic infections. PRRS disease severity and consequently financial losses can vary greatly between endemically infected farms and estimation of damage is challenging. This study aimed to assess the economic effect of PRRS in a systematic way at individual farm-level for endemically infected herds, using a PRRS cost simulation tool. In total 21 German sow herds with endemic PRRSV infection were investigated. Data on health and production performance, farm management and environment to be fed into the calculator was collected on each farm, and blood samples taken to confirm the PRRSV status. RESULTS: All study farms experienced a significant loss attributable to PRRS. The median farm budget across all farms was - 31 € per sow and year, compared to a median simulated farm budget of 248 € if these farms had been PRRSV negative. The median total loss attributable to PRRS was 74,181 € per farm per year, corresponding to a median total loss per sow and year of 255 €. The impact of PRRS on farm profits was - 19.1% on average and - 41% in the worst case. CONCLUSIONS: The calculated losses give a good hint of the economic damage due to PRRS for the pig industry. Even in endemically infected farms, farmers face a non-negligible damage and profit from a concerted PRRS control. The calculator has proven itself in the field to render a valid estimation of losses due to PRRS in endemically infected farms.

11.
Phys Med Biol ; 66(5): 055012, 2021 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-33477131

RESUMEN

Model-based iterative reconstruction (MBIR) for cone-beam CT (CBCT) offers better noise-resolution tradeoff and image quality than analytical methods for acquisition protocols with low x-ray dose or limited data, but with increased computational burden that poses a drawback to routine application in clinical scenarios. This work develops a comprehensive framework for acceleration of MBIR in the form of penalized weighted least squares optimized with ordered subsets separable quadratic surrogates. The optimization was scheduled on a set of stages forming a morphological pyramid varying in voxel size. Transition between stages was controlled with a convergence criterion based on the deviation between the mid-band noise power spectrum (NPS) measured on a homogeneous region of the evolving reconstruction and that expected for the converged image, computed with an analytical model that used projection data and the reconstruction parameters. A stochastic backprojector was developed by introducing a random perturbation to the sampling position of each voxel for each ray in the reconstruction within a voxel-based backprojector, breaking the deterministic pattern of sampling artifacts when combined with an unmatched Siddon forward projector. This fast, forward and backprojector pair were included into a multi-resolution reconstruction strategy to provide support for objects partially outside of the field of view. Acceleration from ordered subsets was combined with momentum accumulation stabilized with an adaptive technique that automatically resets the accumulated momentum when it diverges noticeably from the current iteration update. The framework was evaluated with CBCT data of a realistic abdomen phantom acquired on an imaging x-ray bench and with clinical CBCT data from an angiography robotic C-arm (Artis Zeego, Siemens Healthineers, Forchheim, Germany) acquired during a liver embolization procedure. Image fidelity was assessed with the structural similarity index (SSIM) computed with a converged reconstruction. The accelerated framework provided accurate reconstructions in 60 s (SSIM = 0.97) and as little as 27 s (SSIM = 0.94) for soft-tissue evaluation. The use of simple forward and backprojectors resulted in 9.3× acceleration. Accumulation of momentum provided extra ∼3.5× acceleration with stable convergence for 6-30 subsets. The NPS-driven morphological pyramid resulted in initial faster convergence, achieving similar SSIM with 1.5× lower runtime than the single-stage optimization. Acceleration of MBIR to provide reconstruction time compatible with clinical applications is feasible via architectures that integrate algorithmic acceleration with approaches to provide stable convergence, and optimization schedules that maximize convergence speed.


Asunto(s)
Algoritmos , Tomografía Computarizada de Haz Cónico/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Fantasmas de Imagen , Artefactos , Alemania , Humanos
12.
Obes Surg ; 31(1): 200-206, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32803706

RESUMEN

BACKGROUND: The amount of postoperative weight loss after bariatric surgery varies interindividually. The quality of the pre- and postoperative body composition is an important predictor of success. The aim of this study was to investigate the role of preoperative handgrip strength and phase angle (PhA) as predictors of sustained postoperative weight loss in order to assess the influence of body composition on the postoperative outcome after bariatric surgery. METHOD: In a prospective cohort study, bioelectrical impedance and follow-up data of 198 patients after laparoscopic sleeve gastrectomy (SG; n = 68) and Roux-en-Y gastric bypass (GB; n = 130) were analyzed for a period of 36 months postoperatively. RESULTS: The mean preoperative handgrip strength (31.48 kg, SD 9.97) correlates significantly with the postoperative body composition up to 24 months after surgery. Preoperative PhA, gender, size, and body weight influenced postoperative weight loss significantly. A significant correlation between preoperative PhA (mean 6.18°, SD 0.89°) and total weight loss (%TWL) was observed up to 3 months after SG (r = 0.31444, p = 0.0218) and up to 12 months after GB (r = 0.19184, p = 0.0467). The optimum cutoff for the prediction of a response of less than 50% excess weight loss was a preoperative PhA of 6.0°. CONCLUSIONS: The preoperative handgrip strength confirmed its suitability for use as a predictor of postoperative body composition, whereas the preoperative PhA predicts postoperative weight loss after bariatric surgery. Further research is necessary to identify the role of these parameters for preconditioning.


Asunto(s)
Cirugía Bariátrica , Derivación Gástrica , Laparoscopía , Obesidad Mórbida , Índice de Masa Corporal , Gastrectomía , Fuerza de la Mano , Humanos , Obesidad Mórbida/cirugía , Estudios Prospectivos , Estudios Retrospectivos , Resultado del Tratamiento
13.
AJNR Am J Neuroradiol ; 41(10): 1825-1832, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33023913

RESUMEN

BACKGROUND AND PURPOSE: A new transtentorial venous system consisting of medial, intermediate, and lateral tentorial veins, connecting infra- and supratentorial compartments, was recently shown in 2 cadaver dissections and 2 patient scans. We sought to characterize the venous patterns within the tentorium and their relation to measures of skull development in a cohort of healthy adults. MATERIALS AND METHODS: We retrospectively reviewed tentorial venous anatomy of the head using CTA/CTV performed for routine care or research purposes in 238 patients. Included studies had adequate contrast opacification of venous structures and a section thickness of ≤2 mm; we excluded cases with space-occupying lesions and vascular pathologies. Tentorial angle, dural sinus configurations, and measures of skull base development were assessed as predictors of tentorial venous anatomy variation via Cramér V association, the binary encoded Pearson correlation, and nearest-point algorithm with the Euclidean distance metric for clustering. RESULTS: Tentorial vein development was related to the ringed configuration of the tentorial sinuses (P < .005). There were 3 configurations. Groups 1A and 1B (n = 50/238) had ringed configuration, while group 2 did not (n = 188/238). Group 1A (n = 38/50) had a medialized ringed configuration, and group 1B had a lateralized ringed configuration (n = 12/50). Measurements of skull base development were predictive of these groups. The ringed configuration of group 1 was related to the presence of a split confluens, which correlated with a decreased internal auditory canal-petroclival fissure angle. Configuration 1A was related to the degree of petrous apex pneumatization (P value = .010). CONCLUSIONS: Variations in the transtentorial venous system directly correlate with cranial development.


Asunto(s)
Senos Craneales/anatomía & histología , Duramadre/irrigación sanguínea , Cadáver , Humanos
14.
Stem Cell Rev Rep ; 16(6): 1343-1355, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32880856

RESUMEN

Extracellular vesicles (EVs), a spherical membrane fragments including exosomes, are released from several cell types, including mesenchymal stromal cells (MSCs), constitutively or under stimulation. As MVs cargo include DNA, RNA, miRNA, lipids and proteins their have gain special attention in the field of regenerative medicine. Depending on the type of transferred molecules, MVs may exert wide range of biological effects in recipient cells including pro-inflammatory and anti-apoptotic action. In presented paper, we isolated MVs form adipose derived mesenchymal stem cells (ASC) which underwent stimulation with 5-azacytydine and resveratrol (AZA/RES) in order to improve their therapeutic potential. Then, isolated MVs were applied to ASC with impaired cytophysiological properties, isolated from equine metabolic syndrome diagnosed animals. Using RT-PCR, immunofluorescence, ELISA, confocal microscopy and western blot, we have evaluated the effects of MVs on recipient cells. We have found, that MVs derived from AZA/RES treated ASC ameliorates apoptosis, senescence and endoplasmic reticulum (ER) stress in deteriorated cells, restoring their proper functions. The work indicates, that cells treated with AZA/RES through their paracrine action can rejuvenate recipient cells. However, further research needs to be performed in order to fully understand the molecular mechanisms of these bioactive factors action. Graphical Abstract Graphical abstract of presented study.


Asunto(s)
Azacitidina/farmacología , Estrés del Retículo Endoplásmico/efectos de los fármacos , Vesículas Extracelulares/metabolismo , Células Madre Mesenquimatosas/patología , Síndrome Metabólico/patología , Síndrome Metabólico/terapia , Resveratrol/farmacología , Animales , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Citocinas/metabolismo , Vesículas Extracelulares/efectos de los fármacos , Femenino , Caballos , Inflamación/patología , Masculino , Estrés Oxidativo/efectos de los fármacos
15.
Urologe A ; 59(9): 1067-1075, 2020 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-32347325

RESUMEN

BACKGROUND AND OBJECTIVES: The congress of the German Society of Urology reflects urologic research in German-speaking countries. The objective was to identify trends by analyzing the congress' abstracts and following full publications longitudinally. MATERIALS AND METHODS: The abstracts of the 2016 congress were systematically analyzed regarding content, study design, cooperation, following full publications and journals which they were published in. Thereafter, the 2016 congress was compared to the 2002 and 2009 congresses. Statistical analysis included χ2-, Mann-Whitney U-, Cochran-Armitage-, and Kruskal-Wallis test. RESULTS: A total of 1073 abstracts were presented at the 2002, 2009, and 2016 congresses. We found an increase in abstracts regarding prostate disease (24.2%, 29.7%, and 34.0%; p = 0.0043), oncological abstracts (50.6%, 57.9%, and 61.7%; p = 0.003), multicenter studies (18.3, 28.6, and 34.3%; p < 0.0001) and cooperation (55.6%, 62.9%, and 70.5%, p < 0.0001). Experimental (29.0%, 33.2%, and 22.8%; p = 0.009) and prospective studies (62.1%, 42.0%, and 36.0%; p < 0.0001) declined. Abstracts including statistical analysis (18.4%, 14.7%, and 41.2%; p < 0.0001) and the impact factor of following full publications (2.08, 3.42, 4.42; p < 0.0001) rose. In 2016, 11.2% of those full publications were published Open Access. The publication rates of the presented abstracts were 49.1%, 56.3%, and 52.3%, respectively (p = 0.15). CONCLUSIONS: National and international networking of the urological research community has increased. Presentation of prospective studies has declined. The rate of peer-reviewed full publications following the DGU abstracts remains at a stable high level over the three congresses. The publication rate in Open Access journals is low.


Asunto(s)
Edición , Investigación , Urología , Alemania , Humanos , Estudios Longitudinales , Masculino , Estudios Retrospectivos , Sociedades Médicas
16.
World J Urol ; 38(2): 447-453, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31073641

RESUMEN

PURPOSE: To compare iPad-assisted (Apple Inc., Cupertino, USA) percutaneous access to the kidney to the standard puncturing technique for percutaneous nephrolithotomy (PCNL). METHODS: For the iPad-assisted PCNL, a computed tomography is performed prior to surgery, using fiducial radiopaque markers. The important anatomical structures (i.e. kidney, stones) are segmented using specific software enabling the superimposition of images semi-transparently on the iPad by marker-based navigation. Twenty-two patients underwent an iPad-assisted percutaneous puncture of the kidney for PCNL. Twenty-two patients of the clinical database from the Urological Department SLK Hospital Heilbronn, who underwent the standard puncturing technique, were matched to these patients. Matching criteria were age, gender, stone volume, body mass index, stone site and the absence of anatomical variation. Puncture time, radiation exposure and number of attempts for a successful puncture were evaluated. All procedures were performed by two experienced urologists. The standard puncturing method consisted of a combination of ultrasound and fluoroscopy guidance. Chi-square and t test were used to ensure that there was no difference in the matching criteria between the groups. To compare the two methods, U test, Kruskal-Wallis and Chi-square test were used. RESULTS: Examination of radiation exposure showed a significant difference between the two groups in favour of the standard puncturing method (p < 0.01) and puncture time (p = 0.01). However, there was no significant difference in puncturing attempts (p = 0.45). CONCLUSION: The iPad-assisted navigation, with the objective being to puncture the renal collecting system, represents a new technique (IDEAL criteria 2b), which proved to be applicable in clinical practice, but still has potential for technical improvement.


Asunto(s)
Computadoras de Mano , Cálculos Renales/cirugía , Nefrolitotomía Percutánea/métodos , Cirugía Asistida por Computador/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Análisis por Apareamiento , Persona de Mediana Edad , Ultrasonografía , Adulto Joven
17.
Colorectal Dis ; 22(4): 445-451, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31652025

RESUMEN

AIM: Because damage to the rectus abdominis muscle during ileostomy placement and reversal might be a risk factor for the development of stoma-site incisional hernia (SSIH), we hypothesized that positioning of the stoma lateral to the rectus abdominis muscle might prevent SSIH. METHOD: To investigate whether a lateral pararectal stoma position lowers the incidence of SSIH in comparison with a transrectal position, a follow-up study of the PATRASTOM trial, which had randomized stoma placement (lateral pararectal versus transrectal), was conducted. All former participants were invited simultaneously for a follow-up visit in September 2016, 2 years after database closure of the PATRASTOM trial. For patients who were not able to attend the follow-up, the electronic chart as well as MRI/CT scans were reviewed with regard to the presence of SSIH. RESULTS: Follow-up - either clinical or radiological - was available for 47 of the 60 PATRASTOM participants. The median duration of follow-up was 3.4 years (interquartile range 3.0-4.1 years). SSIH occurred in 3 of 23 patients (13.0%) in the lateral pararectal group compared with 7 of 24 patients (29.2%) in the transrectal group (P = 0.287). Four of the 10 patients diagnosed with SSIH had already undergone or were scheduled for hernia repair. Of the patient and procedure characteristics which may have an impact on the development of incisional hernia none was a significant risk factor for SSIH. CONCLUSION: In the present follow-up study, no difference in the incidence of SSIH was found between lateral pararectal and transrectal stoma construction in an elective setting.


Asunto(s)
Hernia Incisional , Estomas Quirúrgicos , Colostomía , Estudios de Seguimiento , Herniorrafia , Humanos , Ileostomía/efectos adversos , Hernia Incisional/etiología , Hernia Incisional/prevención & control , Mallas Quirúrgicas
18.
Int J Comput Assist Radiol Surg ; 15(1): 1-14, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31741287

RESUMEN

PURPOSE: A strong foundation in the fundamental principles of medical intervention combined with genuine exposure to real clinical systems and procedures will improve engineering students' capability for informed innovation on clinical problems. To help build such a foundation, a new course (dubbed Surgineering) was developed to convey fundamental principles of surgery, interventional radiology (IR), and radiation therapy, with an emphasis on experiential learning, hands-on with real clinical systems, exposure to clinicians, and visits to real operating theaters. The concept, structure, and outcomes of the course of the first run of the first semester of the course are described. METHOD: The course included six segments spanning fundamental concepts and cutting-edge approaches in a spectrum of surgical specialties, body and neurological IR, and radiation therapy. Each class involved a minimum of didactic content and an emphasis on hands-on experience with instrumentation, equipment, surgical approaches, anatomical models, dissection, and visits to clinical theaters. Outcomes on the quality of the course and areas for continuing improvement were assessed by student surveys (5-point Likert scores and word-cloud representations of free response) as well as feedback from clinical collaborators. RESULT: Surveys assessed four key areas of feedback on the course and were analyzed quantitatively and in word-cloud representations of: (1) best aspects (hands-on experience with surgeons); (2) worst aspects (quizzes and reading materials); (3) areas for improvement (projects, quizzes, and background on anatomy); and (4) what prospective students should know (a lot background reading for every class). Five-point Likert scores from survey respondents (16/19 students) indicated: overall quality of the course 4.63 ± 0.72 (median 5.00); instructor teaching effectiveness 4.06 ± 1.06 (median 4.00); intellectual challenge 4.19 ± 0.40 (median 4.00); and workload somewhat heavier (62.5%) compared to other courses. Novel elements of the course included the opportunity to engage with clinical faculty and participate in realistic laboratory exercises, work with clinical instruments and equipment, and visit real operating theaters. An additional measure of the success of the course was evidenced by surveys and a strong escalation in enrollment in the following year. CONCLUSIONS: The Surgineering course presents an important addition to upper-level engineering curricula and a valuable opportunity for engineering students to gain hands-on experience and interaction with clinical experts. Close partnership with clinical faculty was essential to the schedule and logistics of the course as well as to the continuity of concepts delivered over the semester. The knowledge and experience gained provides stronger foundation for identification of un-met clinical needs and ideation of new engineering approaches in medicine. The course also provides a valuable prerequisite to higher-level coursework in systems engineering, human factors, and data science applied to medicine.


Asunto(s)
Ingeniería Biomédica/educación , Curriculum , Educación de Postgrado en Medicina/métodos , Aprendizaje Basado en Problemas/métodos , Humanos , Estudios Prospectivos
19.
Oxid Med Cell Longev ; 2019: 1523140, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31214275

RESUMEN

Recently, metabolic syndrome (MS) has gained attention in human and animal metabolic medicine. Insulin resistance, inflammation, hyperleptinemia, and hyperinsulinemia are critical to its definition. MS is a complex cluster of metabolic risk factors that together exert a wide range of effects on multiple organs, tissues, and cells in the body. Adipose stem cells (ASCs) are multipotent stem cell population residing within the adipose tissue that is inflamed during MS. Studies have indicated that these cells lose their stemness and multipotency during MS, which strongly reduces their therapeutic potential. They suffer from oxidative stress, apoptosis, and mitochondrial deterioration. Thus, the aim of this study was to rejuvenate these cells in vitro in order to improve their chondrogenic differentiation effectiveness. Pharmacotherapy of ASCs was based on resveratrol and 5-azacytidine pretreatment. We evaluated whether those substances are able to reverse aged phenotype of metabolic syndrome-derived ASCs and improve their chondrogenic differentiation at its early stage using immunofluorescence, transmission and scanning electron microscopy, real-time PCR, and flow cytometry. Obtained results indicated that 5-azacytidine and resveratrol modulated mitochondrial dynamics, autophagy, and ER stress, leading to the enhancement of chondrogenesis in metabolically impaired ASCs. Therefore, pretreatment of these cells with 5-azacytidine and resveratrol may become a necessary intervention before clinical application of these cells in order to strengthen their multipotency and therapeutic potential.


Asunto(s)
Autofagia/efectos de los fármacos , Azacitidina/farmacología , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/patología , Síndrome Metabólico/fisiopatología , Mitocondrias/metabolismo , Resveratrol/farmacología , Tejido Adiposo/citología , Animales , Diferenciación Celular , Autorrenovación de las Células , Células Cultivadas , Condrogénesis , Femenino , Citometría de Flujo , Enfermedades de los Caballos , Caballos , Humanos , Masculino , Síndrome Metabólico/terapia , Microscopía Electrónica , Nicho de Células Madre
20.
J Chem Phys ; 150(18): 184706, 2019 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-31091921

RESUMEN

Dwindling fossil fuels force humanity to search for new energy production routes. Besides energy generation, its storage is a crucial aspect. One promising approach is to store energy from the sun chemically in strained organic molecules, so-called molecular solar thermal (MOST) systems, which can release the stored energy catalytically. A prototypical MOST system is norbornadiene/quadricyclane (NBD/QC) whose energy release and surface chemistry need to be understood. Besides important key parameters such as molecular weight, endergonic reaction profiles, and sufficient quantum yields, the position of the absorption onset of NBD is crucial to cover preferably a large range of sunlight's spectrum. For this purpose, one typically derivatizes NBD with electron-donating and/or electron-accepting substituents. To keep the model system simple enough to be investigated with photoemission techniques, we introduced bromine atoms at the 2,3-position of both compounds. We study the adsorption behavior, energy release, and surface chemistry on Ni(111) using high-resolution X-ray photoelectron spectroscopy (HR-XPS), UV photoelectron spectroscopy, and density functional theory calculations. Both Br2-NBD and Br2-QC partially dissociate on the surface at ∼120 K, with Br2-QC being more stable. Several stable adsorption geometries for intact and dissociated species were calculated, and the most stable structures are determined for both molecules. By temperature-programmed HR-XPS, we were able to observe the conversion of Br2-QC to Br2-NBD in situ at 170 K. The decomposition of Br2-NBD starts at 190 K when C-Br bond cleavage occurs and benzene and methylidene are formed. For Br2-QC, the cleavage already occurs at 130 K when cycloreversion to Br2-NBD sets in.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...