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1.
Appl Opt ; 59(8): 2270-2275, 2020 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-32225757

RESUMEN

X-ray phase-contrast techniques are powerful methods for discerning features with similar densities, which are normally indistinguishable with conventional absorption contrast. While these techniques are well-established tools at large-scale synchrotron facilities, efforts have increasingly focused on implementations at laboratory sources for widespread use. X-ray speckle-based imaging is one of the phase-contrast techniques with high potential for translation to conventional x-ray systems. It yields phase-contrast, transmission, and dark-field images with high sensitivity using a relatively simple and cost-effective setup tolerant to divergent and polychromatic beams. Recently, we have introduced the unified modulated pattern analysis (UMPA) [Phys. Rev. Lett.118, 203903 (2017)PRLTAO0031-900710.1103/PhysRevLett.118.203903], which further simplifies the translation of x-ray speckle-based imaging to low-brilliance sources. Here, we present the proof-of-principle implementation of UMPA speckle-based imaging at a microfocus liquid-metal-jet x-ray laboratory source.

2.
Artículo en Inglés | MEDLINE | ID: mdl-32952375

RESUMEN

Two types of shaking coils are focused on reducing screening currents induced in solenoid coils wound with high-temperature superconducting (HTS) tapes. One is a pair of copper shaking coils coaxially located inside and outside the HTS coil to apply an ac magnetic field in the axial direction. The other is an HTS shaking coil with notch located only outside the HTS coil to minimize the radial components of local ac fields applied to windings of the HTS coil as small as possible. It is found that the copper shaking coils yield the allowable amount of power dissipation in liquid helium. The effectiveness of the HTS shaking coil to reduce screening-current-induced fields generated by another magnetized HTS coil is also experimentally validated in liquid nitrogen using a commercially available coated conductor with narrow width.

3.
Phys Rev Lett ; 112(25): 253903, 2014 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-25014818

RESUMEN

We report on the observation and application of near-field speckles with a laboratory x-ray source. The detection of speckles is possible thanks to the enhanced brilliance properties of the used liquid-metal-jet source, and opens the way to a range of new applications in laboratory-based coherent x-ray imaging. Here, we use the speckle pattern for multimodal imaging of demonstrator objects. Moreover, we introduce algorithms for phase and dark-field imaging using speckle tracking, and we show that they yield superior results with respect to existing methods.

4.
Forensic Sci Int ; 361: 112072, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38838610

RESUMEN

Aquatic decomposition, as a forensic discipline, has been largely under-investigated as a consequence of the highly complex and influential variability of the water environment. The limitation to the adaptability of scenario specific results justifies the necessity for experimental research to increase our understanding of the aquatic environment and the development of post-mortem submersion interval (PMSI) methods of estimation. This preliminary research aims to address this contextual gap by assessing the variation in the bacterial composition of aquatic biofilms as explained by water parameter measurements over time, associated with clothed and bare decomposing remains. As part of three field investigations, a total of 9 still-born piglets (n = 3, per trial) were used as human analogues and were submerged bare or clothed in either natural cotton or synthetic nylon. Changes in the bacterial community composition of the water surrounding the submerged remains were assessed at 4 discrete time points post submersion (7, 14, 21 and 28 days) by 16 S rRNA gene Next Generation Sequencing analysis and compared to coinciding water parameter measurements (i.e. conductivity, total dissolved solids (TDS), salinity, pH, and dissolved oxygen (DO)). Bacterial diversity was found to change over time and relative to clothing type, where significant variation was observed between synthetic nylon samples and bare/cotton samples. Seasonality was a major driver of bacterial diversity, where substantial variation was found between samples collected in early winter to those collected in mid - late winter. Water parameter measures of pH, salinity and DO were identified to best explain the global bacterial community composition and their corresponding dynamic trajectory patterns overtime. Further investigation into bacterial community dynamics in accordance with varying environmental conditions could potentially lead to the determination of influential extrinsic factors that may drive bacterial activity in aquatic decomposition. Together with the identification of potential bacterial markers that complement the different stages of decomposition, this may provide a future approach to PMSI estimations.


Asunto(s)
Biopelículas , Inmersión , Cambios Post Mortem , ARN Ribosómico 16S , Microbiología del Agua , Animales , Porcinos , Modelos Animales , Bacterias/aislamiento & purificación , Bacterias/genética , Bacterias/clasificación , Secuenciación de Nucleótidos de Alto Rendimiento , Concentración de Iones de Hidrógeno , Salinidad , Vestuario , Oxígeno , Estaciones del Año , Nylons , Microbiota
5.
Opt Express ; 21(24): 29101-8, 2013 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-24514461

RESUMEN

We present a spectral phase unwrapping approach for grating-based differential phase-contrast data where the unwrapped interferometer phase shift is estimated from energy discriminated measurements using maximum likelihood principles. We demonstrate the method on tomographic data sets of a test specimen taken at different x-ray energies using synchrotron radiation. The proposed unwrapping technique was demonstrated to successfully correct the data set for phase wrapping.


Asunto(s)
Algoritmos , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Difracción de Rayos X/métodos , Funciones de Verosimilitud , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
7.
Front Behav Neurosci ; 15: 699592, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34234655

RESUMEN

Despite decades of research on the neurobiology of major depressive disorder (MDD), the mechanisms underlying its expression remain unknown. The medial prefrontal cortex (mPFC), a hub region involved in emotional processing and stress response elaboration, is highly impacted in MDD patients and animal models of chronic stress. Recent advances showed alterations in the morphology and activity of mPFC neurons along with profound changes in their transcriptional programs. Studies at the circuitry level highlighted the relevance of deciphering the contributions of the distinct prefrontal circuits in the elaboration of adapted and maladapted behavioral responses in the context of chronic stress. Interestingly, MDD presents a sexual dimorphism, a feature recognized in the molecular field but understudied on the circuit level. This review examines the recent literature and summarizes the contribution of the mPFC circuitry in the expression of MDD in males and females along with the morphological and functional alterations that change the activity of these neuronal circuits in human MDD and animal models of depressive-like behaviors.

8.
Mol Cell Biol ; 41(4)2021 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-33526451

RESUMEN

The nuclear and subnuclear compartmentalization of the telomerase-associated protein and H/ACA ribonucleoprotein component dyskerin is an important although incompletely understood aspect of H/ACA ribonucleoprotein function. Four SUMOylation sites were previously identified in the C-terminal nuclear/nucleolar localization signal (N/NoLS) of dyskerin. We found that a cytoplasmic localized C-terminal truncation variant of dyskerin lacking most of the C-terminal N/NoLS represents an under-SUMOylated variant of dyskerin compared to wild-type dyskerin. We demonstrate that mimicking constitutive SUMOylation of dyskerin using a SUMO3 fusion construct can drive nuclear accumulation of this variant and that the SUMO site K467 in this N/NoLS is particularly important for the subnuclear localization of dyskerin to the nucleolus in a mature H/ACA complex assembly- and SUMO-dependent manner. We also characterize a novel SUMO-interacting motif in the mature H/ACA complex component GAR1 that mediates the interaction between dyskerin and GAR1. Mislocalization of dyskerin, either in the cytoplasm or excluded from the nucleolus, disrupts dyskerin function and leads to reduced interaction of dyskerin with the telomerase RNA. These data indicate a role for dyskerin C-terminal N/NoLS SUMOylation in regulating the nuclear and subnuclear localization of dyskerin, which is essential for dyskerin function as both a telomerase-associated protein and as an H/ACA ribonucleoprotein.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Citoplasma/metabolismo , Ribonucleoproteínas Nucleolares Pequeñas/metabolismo , Sumoilación/fisiología , Núcleo Celular/metabolismo , Disqueratosis Congénita/genética , Disqueratosis Congénita/metabolismo , Humanos , Señales de Localización Nuclear/genética , Proteínas Nucleares/metabolismo , ARN/metabolismo , Proteínas de Unión al ARN/metabolismo , Telomerasa/metabolismo
9.
Front Behav Neurosci ; 15: 714810, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34483859

RESUMEN

Major depressive disorder (MDD) is one of the most common consequences of chronic stress. Still, there is currently no reliable biomarker to detect individuals at risk to develop the disease. Recently, the retina emerged as an effective way to investigate psychiatric disorders using the electroretinogram (ERG). In this study, cone and rod ERGs were performed in male and female C57BL/6 mice before and after chronic social defeat stress (CSDS). Mice were then divided as susceptible or resilient to stress. Our results suggest that CSDS reduces the amplitude of both oscillatory potentials and a-waves in the rods of resilient but not susceptible males. Similar effects were revealed following the analysis of the cone b-waves, which were faster after CSDS in resilient mice specifically. In females, rod ERGs revealed age-related changes with no change in cone ERGs. Finally, our analysis suggests that baseline ERG can predict with an efficacy up to 71% the expression of susceptibility and resilience before stress exposition in males and females. Overall, our findings suggest that retinal activity is a valid biomarker of stress response that could potentially serve as a tool to predict whether males and females will become susceptible or resilient when facing CSDS.

10.
Biol Psychiatry ; 90(3): 194-205, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-33867113

RESUMEN

BACKGROUND: The medial prefrontal cortex (mPFC) is part of a complex circuit controlling stress responses by sending projections to different limbic structures including the nucleus accumbens (NAc) and ventral tegmental area (VTA). However, the impact of chronic stress on NAc- and VTA-projecting mPFC neurons is still unknown, and the distinct contribution of these pathways to stress responses in males and females is unclear. METHODS: Behavioral stress responses were induced by 21 days of chronic variable stress in male and female C57BL/6NCrl mice. An intersectional viral approach was used to label both pathways and assess the functional, morphological, and transcriptional adaptations in NAc- and VTA-projecting mPFC neurons in stressed males and females. Using chemogenetic approaches, we modified neuronal activity of NAc-projecting mPFC neurons to decipher their contribution to stress phenotypes. RESULTS: Chronic variable stress induced depressive-like behaviors in males and females. NAc- and VTA-projecting mPFC neurons exhibited sex-specific functional, morphological, and transcriptional alterations. The functional changes were more severe in females in NAc-projecting mPFC neurons, while males exhibited more drastic reductions in dendritic complexity in VTA-projecting mPFC neurons after chronic variable stress. Finally, chemogenetic overactivation of the corticoaccumbal pathway triggered anxiety and behavioral despair in both sexes, while its inhibition rescued the phenotype only in females. CONCLUSIONS: Our results suggest that stress responses in males and females result from pathway-specific changes in the activity of transcriptional programs controlling the morphological and synaptic properties of corticoaccumbal and corticotegmental pathways in a sex-specific fashion.


Asunto(s)
Núcleo Accumbens , Área Tegmental Ventral , Animales , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Neuronas , Corteza Prefrontal
11.
Rech Soins Infirm ; (102): 50-8, 2010 Sep.
Artículo en Francés | MEDLINE | ID: mdl-20957803

RESUMEN

A real health priority for governments, breastfeeding has prompted WHO and UNICEF to create the "Baby-Friendly Hospital Initiative" for maternity units respecting the "ten steps to successful breastfeeding". This effort does not include pediatric departments. However, as the properties of breast milk enhance recovery of the infant, it is also important to promote breastfeeding in this branch. Furthermore, few studies have analyzed the constraints of hospitalization on the breastfeeding process. The aim of this study is to identify the constraints imposed by hospitalization on the process of breastfeeding in infants aged 29 days to 6 months suffering from acute disease, during hospitalization and within a week following their return home. This prospective study was conducted between October 1st and December 31st, 2008 in a pediatric department through interviews and questionnaires from breastfeeding mothers and health professionals. 51 mother-infant pairs and 35 caregivers were included in the study. During hospitalization; direct breastfeeding was interrupted for 31 mothers. After hospitalization, 3 mothers had weaned their babies, 12 went from exclusive breastfeeding to mixed feeding and 13 had experienced difficulties. Caregivers partially meet WHO's recommendations. The hospitalization of an infant disrupts the continuation of breastfeeding. To overcome this, actions must be taken in relation with hospitals, departments and professionals. The study's small sample does not prove that the original training of caregivers influence theirs practices.


Asunto(s)
Lactancia Materna/psicología , Niño Hospitalizado/psicología , Cuidadores/psicología , Femenino , Encuestas Epidemiológicas , Humanos , Lactante , Relaciones Madre-Hijo , Madres/psicología , Destete
12.
Microorganisms ; 8(9)2020 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-32825417

RESUMEN

The mucosal surfaces of fish play numerous roles including, but not limited to, protection against pathogens, nutrient digestion and absorption, excretion of nitrogenous wastes and osmotic regulation. During infection or disease, these surfaces act as the first line of defense, where the mucosal immune system interacts closely with the associated microbiota to maintain homeostasis. This study evaluated microbial changes across the gut and skin mucosal surfaces in yellowtail kingfish displaying signs of gut inflammation, as well as explored the host gene expression in these tissues in order to improve our understanding of the underlying mechanisms that contribute to the emergence of these conditions. For this, we obtained and analyzed 16S rDNA and transcriptomic (RNA-Seq) sequence data from the gut and skin mucosa of fish exhibiting different health states (i.e., healthy fish and fish at the early and late stages of enteritis). Both the gut and skin microbiota were perturbed by the disease. More specifically, the gastrointestinal microbiota of diseased fish was dominated by an uncultured Mycoplasmataceae sp., and fish at the early stage of the disease showed a significant loss of diversity in the skin. Using transcriptomics, we found that only a few genes were significantly differentially expressed in the gut. In contrast, gene expression in the skin differed widely between health states, in particular in the fish at the late stage of the disease. These changes were associated with several metabolic pathways that were differentially expressed and reflected a weakened host. Altogether, this study highlights the sensitivity of the skin mucosal surface in response to gut inflammation.

13.
Anim Microbiome ; 2(1): 26, 2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-33499964

RESUMEN

BACKGROUND: The use of antibiotics in aquaculture is a common infection treatment and is increasing in some sectors and jurisdictions. While antibiotic treatment can negatively shift gut bacterial communities, recovery and examination of these communities in fish of commercial importance is not well documented. Examining the impacts of antibiotics on farmed fish microbiota is fundamental for improving our understanding and management of healthy farmed fish. This work assessed yellowtail kingfish (Seriola lalandi) skin and gut bacterial communities after an oral antibiotic combination therapy in poor performing fish that displayed signs of enteritis over an 18-day period. In an attempt to promote improved bacterial re-establishment after antibiotic treatment, faecal microbiota transplantation (FMT) was also administered via gavage or in the surrounding seawater, and its affect was evaluated over 15 days post-delivery. RESULTS: Antibiotic treatment greatly perturbed the global gut bacterial communities of poor-performing fish - an effect that lasted for up to 18 days post treatment. This perturbation was marked by a significant decrease in species diversity and evenness, as well as a concomitant increase in particular taxa like an uncultured Mycoplasmataceae sp., which persisted and dominated antibiotic-treated fish for the entire 18-day period. The skin-associated bacterial communities were also perturbed by the antibiotic treatment, notably within the first 3 days; however, this was unlike the gut, as skin microbiota appeared to shift towards a more 'normal' (though disparate) state after 5 days post antibiotic treatment. FMT was only able to modulate the impacts of antibiotics in some individuals for a short time period, as the magnitude of change varied substantially between individuals. Some fish maintained certain transplanted gut taxa (i.e. present in the FMT inoculum; namely various Aliivibrio related ASVs) at Day 2 post FMT, although these were lost by Day 8 post FMT. CONCLUSION: As we observed notable, prolonged perturbations induced by antibiotics on the gut bacterial assemblages, further work is required to better understand the processes/dynamics of their re-establishment following antibiotic exposure. In this regard, procedures like FMT represent a novel approach for promoting improved microbial recovery, although their efficacy and the factors that support their success requires further investigation.

14.
Eur Phys J E Soft Matter ; 28(2): 183-98, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19139943

RESUMEN

We have investigated the formation of helium droplets in two physical situations. In the first one, droplets are atomised from superfluid or normal liquid by a fast helium vapour flow. In the second, droplets of normal liquid are formed inside porous glasses during the process of helium condensation. The context, aims, and results of these experiments are reviewed, with focus on the specificity of light scattering by helium. In particular, we discuss how, for different reasons, the closeness to unity of the index of refraction of helium allows in both cases to minimise the problem of multiple scattering and obtain results which it would not be possible to get using other fluids.

15.
Sci Rep ; 9(1): 5814, 2019 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-30967595

RESUMEN

Cereulide is a toxic cyclic depsipeptide produced by certain strains of Bacillus cereus found in soil and food products. While some harmless strains of Bacillus are used as probiotic, others can cause nausea and vomiting, and represent an important food safety concern. Current detection methods are time consuming and do not necessarily detect toxic cereulide. Here, we developed a rapid protocol using Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometry that detects the toxin originating from a colony smear of B. cereus. The distinct molecular feature of the toxin peak at m/z 1,191 was clearly identified from bacterial extracts with a limit of detection (LOD) of 30 ng/mL. Final optimisation of the sample preparation was based on cereulide chelating cations to produce the alkali adduct [M + K]+ without the use of a MALDI matrix, and provided a 1,000-fold improvement of LOD with 30 pg/mL of cereulide. We evaluated the application of this method for the detection of cereulide in rice, milk, and different ready-to-eat meals. The proposed protocol is quick, easy and provides an improvement over conventional methods for the detection of B. cereus toxin.


Asunto(s)
Bacillus cereus/metabolismo , Toxinas Bacterianas/análisis , Depsipéptidos/análisis , Contaminación de Alimentos/análisis , Microbiología de Alimentos/métodos , Secuencia de Aminoácidos , Animales , Comida Rápida/microbiología , Inocuidad de los Alimentos/métodos , Límite de Detección , Leche/química , Oryza/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos
16.
Neuropharmacology ; 154: 79-86, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30771372

RESUMEN

Corticosteroid stress hormones drive a multitude of adaptations in the brain. Hypothalamic corticotropin-releasing hormone (CRH) neurons control the circulating levels of corticosteroid stress hormones in the body and are themselves highly sensitive to corticosteroids. CRH neurons have been shown to undergo various adaptions in response to acute stress hormone elevations. However, their structural and physiological changes under chronically elevated corticosterone are less clear. To address this, we determined the structural and functional changes in CRH neurons in the paraventricular nucleus of the hypothalamus following 14 days of corticosterone treatment. We find that prolonged corticosterone elevation reduces CRH neuron intrinsic excitability as measured by summation of subthreshold postsynaptic depolarisations and spiking output. We find that under normal conditions, CRH neurons have a relatively compact and simple dendritic arbor, with a low density of somatic and dendritic spines. Interestingly, the axon originated from a proximal dendrite close to the soma in approximately half of the CRH neurons reconstructed. While prolonged elevation in corticosterone levels did not result in any changes to gross dendritic morphology, it induced a significant reduction in both somatic and dendritic spine density. Together these data reveal the morphological features of hypothalamic CRH neurons and highlight their capacity to undergo functional and morphological plasticity in response to chronic corticosterone elevations. This article is part of the Special Issue entitled 'Hypothalamic Control of Homeostasis'.


Asunto(s)
Corticosterona/administración & dosificación , Corticosterona/sangre , Hormona Liberadora de Corticotropina/sangre , Plasticidad Neuronal/fisiología , Neuronas/patología , Neuronas/fisiología , Animales , Espinas Dendríticas/efectos de los fármacos , Espinas Dendríticas/patología , Espinas Dendríticas/fisiología , Ratones , Ratones Transgénicos , Plasticidad Neuronal/efectos de los fármacos , Neuronas/efectos de los fármacos
17.
Urol Int ; 80(1): 102-4; discussion 104, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18204243

RESUMEN

Renal angiomyolipomas (AMLs) are mesenchymal tumors that occur either sporadically or are associated with tuberous sclerosis, and are generally considered to be benign. Malignant AML is extremely rare, and most are found to be epithelioid histopathologically. The authors report the case of a patient followed for renal AML. On CT surveillance, this lesion developed features of a malignant tumor involving the renal vein and inferior vena cava. The patient was treated by nephrectomy and tumor thrombectomy with retroperitoneal lymph node dissection. Histological examination demonstrated renal AML with a malignant epithelioid contingent. The various aspects of this histological and radiological variant are discussed.


Asunto(s)
Angiomiolipoma/complicaciones , Epitelio/patología , Neoplasias Renales/complicaciones , Esclerosis Tuberosa/complicaciones , Vena Cava Inferior/patología , Adulto , Angiomiolipoma/patología , Femenino , Humanos , Neoplasias Renales/patología , Oncología Médica/métodos , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento , Esclerosis Tuberosa/patología , Urología/métodos
18.
Pain Res Manag ; 13(3): 236-42, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18592061

RESUMEN

OBJECTIVES: The primary objective of the present study was to examine the role of sex as a moderator of the relation between depression and activity-related pain. METHODS: The study sample consisted of 83 participants (42 women, 41 men) with musculoskeletal conditions. Participants were asked to lift a series of 18 canisters that varied in weight (2.9 kg, 3.4 kg and 3.9 kg) and distance from the body. Participants were asked to rate their pain while they lifted each canister and estimate the weight of the canisters. RESULTS: Consistent with previous research, the relations among depression, pain intensity and disability were stronger for women than for men. ANOVA revealed that depression was associated with more intense activity-related pain in women only. For both women and men, the intensity of pain increased with each trial, although the weight of the objects lifted remained constant. Neither sex nor depression had an effect on participants' weight estimates. CONCLUSIONS: The present discussion addresses the mechanisms through which depression may differentially affect pain in women and men. It also addresses the potential clinical implications of pain-augmenting effects of depression in women.


Asunto(s)
Depresión/psicología , Movimiento/fisiología , Enfermedades Musculoesqueléticas/psicología , Dolor/psicología , Adulto , Enfermedad Crónica , Depresión/complicaciones , Evaluación de la Discapacidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Musculoesqueléticas/complicaciones , Dolor/etiología , Dimensión del Dolor , Escalas de Valoración Psiquiátrica , Caracteres Sexuales , Percepción del Peso/fisiología
19.
Prog Urol ; 18(5): 318-22, 2008 May.
Artículo en Francés | MEDLINE | ID: mdl-18538278

RESUMEN

OBJECTIVE: To review the various clinical forms of female urethral cancer in the light of three clinical cases with a review of the corresponding treatment guidelines. METHOD: The authors report three cases of female urethral cancer. Case 1 consisted of squamous cell carcinoma in a 56-year-old woman with no particular history. Case 2 was a urothelial tumour arising in a urethral diverticulum in a 60-year-old smoker. Case 3 was a 69-year-old woman patient with invasive urothelial carcinoma. RESULTS: Case 1 was treated by segmental urethrectomy with no adjuvant therapy and a favourable course. Case 2 was treated by anterior pelvic exenteration with no adjuvant therapy. This patient relapsed in the form of peritoneal carcinomatosis two years later and died. Case 3 was initially treated by anterior pelvic exenteration followed by a chemoradiotherapy combination after local recurrence with a favourable course. CONCLUSION: There are many clinical presentations and histological forms of female urethral cancer. Localized distal lesions can be treated by simple circumferential resection. The treatment of other lesions comprises anterior pelvic exenteration and platinum- or M-VAC-based chemoradiotherapy. The main prognostic factors for these tumours are their size, histological type, site and the presence of pelvic lymph node extension.


Asunto(s)
Carcinoma/cirugía , Neoplasias Uretrales/cirugía , Anciano , Carcinoma/patología , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/terapia , Neoplasias Uretrales/patología
20.
Prog Urol ; 18(6): 344-50, 2008 Jun.
Artículo en Francés | MEDLINE | ID: mdl-18558322

RESUMEN

INTRODUCTION: Several teams have recently confirmed the technical feasibility of laparoscopic partial nephrectomy (LPN). However, this procedure is not widely performed because it is technically difficult and associated with a high rate of bleeding complications, even for experienced teams. The authors studied the LPN learning curve for urology residents using a porcine model based on analysis of the following criteria: operating time, warm ischaemia time and intraoperative and postoperative bleeding. MATERIALS AND METHODS: Forty LPN were performed by the same operator. All operations were performed after arterial clamping and heparinisation of the animal. The renal section was always the same, removing 40% of the kidney and always comprised the excretory tract. A continuous running suture on the excretory tract and interrupted sutures on the parenchyma were performed. Operating time and warm ischaemia time were recorded. Animals were monitored for ten days. Intraoperative and postoperative bleeding via drains was recorded and retrograde urography was performed on the 10th day to confirm the absence of excretory tract leaks. Linear regression statistical tests investigated a correlation between these various criteria and the number of cases performed. RESULTS: The mean total operating time, warm ischaemia time and total bleeding (intraoperative and postoperative) were 108 minutes (70-140 minutes), 38 minutes (22-50 minutes) and 95 ml (10-300 ml), respectively. Linear regression analysis revealed a direct correlation between the number of cases performed and intraoperative bleeding (p<0.001) and warm ischaemia time (p<0.001). These parameters became stable after the 10th operated case. Two cases of urine leaks were observed on D10 out of a series of 40 operations, with no correlation with the number of cases performed. CONCLUSION: The operating time and warm ischaemia time are directly correlated with the number of cases performed. Training on a porcine model appears to be a good way to reduce the learning curve in man. Ten operations are necessary to acquire the various steps of the procedure.


Asunto(s)
Internado y Residencia , Laparoscopía , Nefrectomía/métodos , Urología/educación , Animales , Pérdida de Sangre Quirúrgica , Estudios de Seguimiento , Francia , Aprendizaje , Modelos Lineales , Masculino , Modelos Animales , Técnicas de Sutura , Porcinos , Factores de Tiempo
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