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1.
Phys Rev Lett ; 131(5): 056201, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37595244

RESUMO

We consider the stability of precipitates formed at grain boundaries (GBs) by radiation-induced segregation in dilute alloys subjected to irradiation. The effects of grain size and misorientation of symmetric-tilt GBs are quantified using phase field modeling. A novel regime is identified where, at long times, GBs are decorated by precipitate patterns that resist coarsening. Maps of the chemical Péclet number indicate that arrested coarsening takes place when solute advection dominates over thermal diffusion right up to the precipitate-matrix interface, preventing interfacial local equilibrium and overriding capillary effects. This contrasts with liquid-solid mixtures where convection always accelerates coarsening.

2.
Radiologia (Engl Ed) ; 64(3): 228-236, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35676054

RESUMO

The interpretation of medical imaging tests is one of the main tasks that radiologists do. For years, it has been a challenge to teach computers to do this kind of cognitive task; the main objective of the field of computer vision is to overcome this challenge. Thanks to technological advances, we are now closer than ever to achieving this goal, and radiologists need to become involved in this effort to guarantee that the patient remains at the center of medical practice. This article clearly explains the most important theoretical concepts in this area and the main problems or challenges at the present time; moreover, it provides practical information about the development of an artificial intelligence project in a radiology department.


Assuntos
Inteligência Artificial , Radiologia , Humanos , Radiografia , Radiologistas , Radiologia/métodos
3.
J Digit Imaging ; 34(2): 242-256, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33686526

RESUMO

In December 2019, a new coronavirus known as 2019-nCoV emerged in Wuhan, China. The virus has spread globally and the infection was declared pandemic in March 2020. Although most cases of coronavirus disease 2019 (COVID-19) are mild, some of them rapidly develop acute respiratory distress syndrome. In the clinical management, chest X-rays (CXR) are essential, but the evaluation of COVID-19 CXR could be a challenge. In this context, we developed COVID-19 TRAINING, a free Web application for training on the evaluation of COVID-19 CXR. The application included 196 CXR belonging to three categories: non-pathological, pathological compatible with COVID-19, and pathological non-compatible with COVID-19. On the training screen, images were shown to the users and they chose a diagnosis among those three possibilities. At any time, users could finish the training session and be evaluated through the estimation of their diagnostic accuracy values: sensitivity, specificity, predictive values, and global accuracy. Images were hand-labeled by four thoracic radiologists. Average values for sensitivity, specificity, and global accuracy were .72, .64, and .68. Users who achieved better sensitivity registered less specificity (p < .0001) and those with higher specificity decreased their sensitivity (p < .0001). Users who sent more answers achieved better accuracy (p = .0002). The application COVID-19 TRAINING provides a revolutionary tool to learn the necessary skills to evaluate COVID-19 on CXR. Diagnosis training applications could provide a new original manner of evaluation for medical professionals based on their diagnostic accuracy values, and an efficient method to collect valuable data for research purposes.


Assuntos
COVID-19 , Radiografia Torácica , Humanos , SARS-CoV-2 , Tomografia Computadorizada por Raios X , Raios X
4.
Actas Dermosifiliogr (Engl Ed) ; 111(4): 291-299, 2020 May.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32241529

RESUMO

BACKGROUND AND OBJECTIVE: Basal cell carcinoma (BCC) is the most common skin cancer in the general population. BCC is managed in a variety of ways, and available international guidelines are difficult to put into practice in Spain. This guideline aims to improve the management of BCC based on current evidence and provide a point of reference for Spanish dermatologists. MATERIAL AND METHODS: Members of the Spanish Oncologic Dermatology and Surgery Group (GEDOC) with experience treating BCC were invited to participate in drafting this guideline. The drafters used the ADAPTE collaboration process to develop the new guideline based on existing ones, first summarizing the care pathway and posing relevant clinical questions. They then searched for guidelines, assessed them with the AGREEII (Appraisal of Guidelines for Research and Evaluation) tool, and searched the selected guidelines for answers to the clinical questions. Finally, the recommendations were drafted and submitted for external review. RESULTS: The highest-scoring guidelines were from the Association of Dermatologists, the National Comprehensive Cancer Network, the European Dermatology Forum, and the European Academy of Dermatology and Venereology. A total of 11 clinical questions were answered. CONCLUSIONS: This new guideline answers the working group's clinical questions about the routine management of BCC in Spain. It provides dermatologists with a tool they can use for decision-making while taking into consideration the resources available and patient preferences.


Assuntos
Carcinoma Basocelular , Dermatologia , Neoplasias Cutâneas , Carcinoma Basocelular/diagnóstico , Humanos , Neoplasias Cutâneas/diagnóstico , Espanha
5.
ACS Appl Mater Interfaces ; 10(17): 15288-15297, 2018 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-29627975

RESUMO

The microscopic wear behavior of copper-silver multilayer samples was studied by performing sliding wear tests using a tribo-indenter. Multilayers with an average composition of Cu90Ag10 and Ag layer thicknesses ranging from 2 to 20 nm were grown by magnetron sputtering. For reference, a homogeneous Cu90Ag10 solid solution film was similarly grown. The thin films were subjected to two-dimensional wear tests by rastering a cono-spherical diamond indenter under loads of 100-400 µN for 1-20 consecutive passes or cycles. The wear volumes were determined by atomic force microscopy. Characterization of the specimens employed nanoindentation, nanoscratch, and transmission electron microscopy (TEM). Wear rates were found to reach steady state after five cycles or less. The hardness values of the as-grown and worn samples both increased with decreasing thickness of the Cu and Ag layers, whereas the steady-state wear rates decreased. Notably, the wear resistance increased faster than the corresponding increase in indentation hardness, indicating a deviation from the Archard's law. An inverse relationship between the wear rate and hardness was, however, recovered when using scratch hardness, suggesting that scratch hardness is a better predictor of wear resistance. Characterization of subsurface wear microstructures by TEM revealed that forced chemical mixing and dissolution of layers occur to a depth of ≈40 to 50 nm, stabilizing a chemically homogeneous solid solution below the wear surface. Comparative wear tests on thicker multilayers revealed that Cu/Ag interfaces reduced the wear rate significantly, thus helping to rationalize the high wear resistance of thin multilayers.

6.
Actas Dermosifiliogr (Engl Ed) ; 109(4): 346-350, 2018 May.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-29373111

RESUMO

BACKGROUND: Regesmohs registry is a nationwide registry including patients evaluated for Mohs surgery in 17 Spanish centres since July 2013. Given that Mohs surgery is the therapy with best results for high risk basal cell carcinoma (BCC) and other skin tumours, we wanted to describe the reasons that lead to some patients being excluded from this therapy and the alternative treatments that they received. These data may be useful to avoid excluding patients for Mohs surgery use, to estimate the healthcare demand of these patients and the demand for Hedgehog inhibitors therapy in this group. OBJECTIVE: To describe patients excluded for Mohs surgery after pre-surgical assessment, and the treatments that they received. METHODS: Regesmohs includes all consecutive patients assessed for Mohs surgery in the participating centres, collecting data on patient characteristics, intervention, and short and long-term results. Patients excluded for Mohs surgery after pre-surgical evaluation were described. RESULTS: 3011 patients were included in Regesmohs from July 2013 to October 2016. In 85, Mohs surgery was not performed as they were considered inadequate candidates. 67 had BCC. Reasons for exclusion were: medical contraindication (27.1%, n=23) low-risk tumour in (18.8%, n=16) and giant tumour and bone invasion (15.3%, n=13). Only 1 patient (1.2%) showed lymph node involvement and no patients had visceral metastases. Of the 85 excluded patients, 29 (34.1%) were treated with conventional surgery, 24 (28.3%) with radiotherapy, 4 (4.7%) with inhibitors of the Hedgehog pathway (only indicated for BCC), and 2 (2.4%) received palliative care. We had no follow-up data on 14 patients (16.5%). CONCLUSION: Medical comorbidities were the most common reason for withholding Mohs surgery. Withholding therapy on the basis of distant extension is uncommon. Most excluded patients received simpler therapies: conventional surgery or radiotherapy, with hedgehog inhibitors being a new option.


Assuntos
Cirurgia de Mohs , Seleção de Pacientes , Neoplasias Cutâneas/cirurgia , Suspensão de Tratamento , Idoso , Idoso de 80 Anos ou mais , Carcinoma Basocelular/tratamento farmacológico , Carcinoma Basocelular/radioterapia , Carcinoma Basocelular/cirurgia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Carcinoma de Células Escamosas/cirurgia , Comorbidade , Contraindicações de Procedimentos , Feminino , Proteínas Hedgehog/antagonistas & inibidores , Humanos , Masculino , Proteínas de Neoplasias/antagonistas & inibidores , Cuidados Paliativos , Estudos Prospectivos , Sistema de Registros , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/radioterapia , Espanha
7.
Actas Dermosifiliogr ; 108(9): 836-843, 2017 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28802488

RESUMO

INTRODUCTION: The Spanish Mohs Surgery Registry is used to collect data on the use and outcomes of Mohs micrographic surgery (MMS) in Spain. The aim of this study was to describe perioperative and intraoperative data recorded for MMS procedures performed between July 2013 (when the registry started) and January 2016. MATERIAL AND METHODS: Prospective cohort study of data from 18 hospitals. The data collected included type of anesthesia, surgical technique, hospital admission, number of Mohs stages, management of preoperative risk factors, additional treatments, previous treatments, type of tumor, operating time, and complications. RESULTS: Data were available for 1796 operations. The most common tumor treated by MMS was basal cell carcinoma (85.96%), followed by squamous cell carcinoma (6.18%), lentigo maligna (2.81%), and dermatofibrosarcoma protuberans (1.97%). Primary tumors accounted for 66.9% of all tumors operated on; 19.2% of tumors were recurrent and 13.9% were persistent. The most common previous treatment was surgical. MMS was mostly performed under local anesthesia (86.7% of cases) and as an outpatient procedure (71.8%). The frozen section technique was used in 89.5% of cases. One stage was needed to achieve tumor-free margins in 56.45% of patients; 2 stages were required in 32.1% of patients, 3 in 7.1%%, 4 in 2.7%, and 5 or more in 1.8%. The defect was reconstructed by the dermatologist in 98% of patients and the most common technique was flap closure (47.2%). Intraoperative complications were recorded for just 1.62% of patients and the median (interquartile range) duration of surgery was 75 (60-100) minutes. CONCLUSION: The characteristics of the patients and tumors treated by MMS are similar to those reported for similar studies in other geographic areas. Lentigo maligna and dermatofibrosarcoma protuberans accounted for a higher proportion of cases in our series, and repair of the surgical defect by a dermatologist was also more common. Operating times in MMS are not much longer than those reported for other procedures and the rate of intraoperative complications is very low.


Assuntos
Cirurgia de Mohs/estatística & dados numéricos , Neoplasias Cutâneas/cirurgia , Idoso , Idoso de 80 Anos ou mais , Anestesia/métodos , Anestesia/estatística & dados numéricos , Terapia Combinada , Feminino , Humanos , Complicações Intraoperatórias/epidemiologia , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Cirurgia de Mohs/métodos , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Procedimentos de Cirurgia Plástica/estatística & dados numéricos , Sistema de Registros , Gestão de Riscos , Neoplasias Cutâneas/terapia , Espanha , Retalhos Cirúrgicos
8.
J Eur Acad Dermatol Venereol ; 31(11): 1924-1929, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28681397

RESUMO

BACKGROUND: Infantile hemangiomas with minimal or arrested growth (IH-MAGs) are characterized by a proliferative component of <25% of its surface area. The co-occurrence of IH-MAGs and soft tissue anomalies is rare, and case series of this association are lacking. OBJECTIVE: We present 10 cases of IH-MAGs associated with soft tissue hypertrophy and describe their clinical features. METHODS: We reviewed all infantile hemangiomas with minimal or arrested growth seen between 2009 and 2016 in the dermatology clinic department at Hospital Santa Creu i Sant Pau, Barcelona. To collect more patients, we also requested cases from the Hemangioma Investigator Group and members of the Spanish Society of Vascular Anomalies. RESULTS: Ten patients had IH-MAGs associated with soft tissue hypertrophy; seven involving the arm and three involving the leg. All displayed a segmental pattern, a doughy and puffy texture and prominent surface veins. No significant asymmetries in limbs and no other visceral anomalies were observed at follow-up (range 15 months to 7 years). One patient reported coldness in the limb with infantile hemangioma, but RMI-angiography did not disclose a vascular malformation underneath the lesion. Ulceration was observed in three patients. The proliferative component in all IH-MAGs had faded at 1-year follow-up, while soft tissue hypertrophy and prominent vessels remained unchanged. CONCLUSIONS: In this first case series of IH-MAGS associated with soft tissue hypertrophy, soft tissue hypertrophy was not progressive and remained unchanged over time, unlike the proliferative component of classic infantile hemangioma. The origin of the prominent vessels and the higher ulceration risk are unknown; however, these findings are probably related to a minor disruption of local vessels not detected in imaging tests.


Assuntos
Hemangioma/patologia , Proliferação de Células , Feminino , Humanos , Hipertrofia , Lactente , Masculino
10.
Actas Dermosifiliogr ; 106(7): 562-8, 2015 Sep.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-26028578

RESUMO

INTRODUCTION: The Spanish registry of Mohs micrographic surgery started collecting data in July 2013. The aim of the registry is to report on the use of this technique in Spain and the outcomes achieved. In the present article, we describe the characteristics of patients and the tumors treated. MATERIAL AND METHODS: This is a prospective cohort study of patients treated with Mohs micrographic surgery. The participating centers are hospitals where at least one intervention of this type is performed each week. All patients considered for Mohs micrographic surgery in participating centers are included in the registry except those who have been declared legally incompetent. RESULTS: Between July 2013 and October 2014, data from 655 patients were included in the registry. The most common tumor involved was basal cell carcinoma, and the most common histological subtype was infiltrative basal cell carcinoma. Most of the tumors treated were located on the face or scalp, and the most common site was the nose. Almost 40% of the tumors treated were recurrent or persistent, and preoperative tumor size was similar to that reported in other European studies and in Australia. In total, 45.5% of patients had received previous surgical treatment. CONCLUSION: The findings are similar to those reported in other studies, and the data collected are useful for assessing whether the results of studies carried out elsewhere are applicable in Spain.


Assuntos
Carcinoma Basocelular/cirurgia , Cirurgia de Mohs/estatística & dados numéricos , Sistema de Registros , Neoplasias Cutâneas/cirurgia , Carcinoma/epidemiologia , Carcinoma/cirurgia , Carcinoma Basocelular/epidemiologia , Terapia Combinada , Bases de Dados Factuais , Dermatofibrossarcoma/epidemiologia , Dermatofibrossarcoma/cirurgia , Neoplasias Faciais/epidemiologia , Neoplasias Faciais/cirurgia , Humanos , Hospedeiro Imunocomprometido , Melanoma/epidemiologia , Melanoma/cirurgia , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/cirurgia , Estudos Prospectivos , Fatores de Risco , Terapia de Salvação , Neoplasias Cutâneas/epidemiologia , Espanha/epidemiologia , Resultado do Tratamento
11.
Actas Dermosifiliogr ; 105(4): 378-93, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24725552

RESUMO

Current trends in our setting indicate that the prevalence of actinic keratosis and similar diseases will increase in coming years and impose a greater burden on health care resources. A long list of clinical features must be taken into account when approaching the treatment of actinic keratosis. Until recently, therapeutic approaches focused solely on ablative procedures and the treatment of individual lesions and did not take into account areas of field cancerization. Now that the therapeutic arsenal has grown, standardized criteria are needed to guide the optimal choice of treatment for each patient. The elaboration of evidence-based consensus recommendations for the diagnosis and treatment of actinic keratosis generates knowledge that will help clinicians to deliver the highest level of care possible, standardizing decision-making processes and enhancing awareness among all the health professionals involved in the care pathway.


Assuntos
Ceratose Actínica/diagnóstico , Ceratose Actínica/terapia , Guias de Prática Clínica como Assunto , Algoritmos , Europa (Continente) , Humanos , Espanha
12.
Arq. Inst. Biol. (Online) ; 78(1): 115-117, jan-mar, 2011. ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-1396421

RESUMO

O presente trabalho buscou desenvolver uma metodologia que possibilita a realização em laboratório, estudos de biologia e avaliação de estratégias de controle a Vatiga manihotae (Drake) (Hemiptera: Tingidae). O trabalho foi conduzido no período de setembro de 2008 a março de 2009. Foram coletadas em campo folhas de mandioca infestadas com ninfas e adultos do percevejo de renda e acondicionadas em gaiolas revestidas com tela antiafídica. Posteriormente, os insetos foram transferidos para bandejas plásticas cobertas com tampa telada. Os pecíolos das folhas de mandioca foram envoltos com algodão hidrófilo umedecido e revestido com papel alumínio, para a manutenção da turgidez da folha, as quais eram trocadas em média a cada dois dias, a fim de garantir a alimentação dos insetos. Após a aplicação dos produtos em teste, folhas da planta de mandioca foram infestadas com ninfas e adultos do inseto, e envoltas em gaiolas foliares confeccionadas com tela antiafídica e polietileno incolor e transparente. Essa técnica mostrou-se favorável para o desenvolvimento de bioensaios com V. manihotae, permitindo obter um grande número de adultos em folhas de mandioca, facilidade de manuseio e baixa mortalidade dos indivíduos.


This study sought to develop a methodology that can be carried out in the laboratory, for studying the biology of Vatiga manihotae (Drake) (Hemiptera: Tingidae) and evaluating the control strategies for this cassava pest. The study was conducted from September 2008 to March 2009. Field collections were made of cassava leaves infested with nymphs and adults of the lacebug, and they were placed in cages lined with anti-aphid screen. Subsequently, the insects were transferred to plastic trays covered with a screened lid. The petioles of cassava leaves were wrapped with moistened cotton wool and covered with aluminum foil to maintain the turgidity of the leaves, which were exchanged on average every 2 days in order to ensure the supply of insects. After application of the test products, cassava leaves were infested with nymphs and adults of V. manihotae, and then wrapped in leaf cages made with colorless, transparent polyethylene screen. This technique proved to be favorable for the development of bioassays with V. manihotae, allowing for a large number of adults in cassava leaves, ease of handling and low mortality of individuals.


Assuntos
Bioensaio/métodos , Hemípteros/fisiologia , Controle de Pragas/métodos , Técnicas de Laboratório Clínico/métodos
13.
Phys Rev Lett ; 99(11): 110602, 2007 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-17930424

RESUMO

We derive expressions for the effective diffusion coefficient of Richardson's pairs in plastically strained solids as a function of the pair separation distance R. We predict that a crossover from superdiffusive to diffusive mixing takes place when R becomes comparable to the coherence length of the shearing events underlying the plastic deformation. Molecular dynamics simulations on nanocrystalline and amorphous systems support this analysis, which thus provides new insight on deformation mechanisms in these systems. Superdiffusive mixing is experimentally observable by monitoring the rate of dissolution of precipitates as a function of their initial size.

14.
Phys Rev Lett ; 95(4): 045901, 2005 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-16090822

RESUMO

Molecular dynamics simulations of forced atomic mixing in crystalline binary alloys during plastic deformation at 100 K are performed. Nearly complete atomic mixing is observed in systems that have a large positive heat mixing and in systems with a large lattice mismatch. Only systems that contained a hard precipitate in a soft matrix do not mix. The amount of mixing is quantified by defining a mean square relative displacement of pairs of atoms, sigma(2)(R,t), that were initially separated by a distance R. Analysis of sigma(2)(R,t) and visual inspection of the displacement fields reveal that forced mixing results from dislocation glide, and that it resembles the forced mixing of a substance advected by a turbulent flow. Consideration of sigma(2)(R,t) also provides a rationalization of compositional self-organization during plastic deformation at higher temperatures.

15.
J Struct Biol ; 149(1): 87-98, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15629660

RESUMO

We have used conical tomography to study the structure of integral proteins in their phospholipid bilayer environments. Complete conical series were collected from replicas of the water channel aquaporin-0 (AQP0), a 6.6 nm side tetramer with a molecular weight of approximately 120 kDa that was purified and reconstituted in liposomes. The replicas were tilted at 38 degrees , 50 degrees or 55 degrees and rotated by 2.5 degrees , 4 degrees , or 5 degrees increments until completing 360 degrees turns. The elliptical paths of between 6 and 12 freeze-fracture particles aligned the images to a common coordinate system. Using the weighted back projection algorithm, small volumes of the replicas were independently reconstructed to reconstitute the field. Using the Fourier Shell Correlation computed from reconstructions of even and odd projections of the series, we estimated a resolution of 2-3 nm, a value that was close to the thickness of the replica (approximately 1.5 nm). The 3D reconstructions exhibited isotropic resolution along the x-y plane, which simplified the analysis of particles oriented randomly in the membrane plane. In contrast to reconstructions from single particles imaged using random conical tilt [J. Mol. Biol. 325 (2003) 210], the reconstructions using conical tomography allowed the size and shape of individual particles representing the AQP0 channel to be identified without averaging or imposing symmetry. In conclusion, the reconstruction of freeze-fracture replicas with electron tomography has provided a novel experimental approach for the study of integral proteins inserted in phospholipid bilayers.


Assuntos
Técnica de Fratura por Congelamento/métodos , Bicamadas Lipídicas/química , Proteínas de Membrana/química , Tomografia/métodos , Aquaporinas , Proteínas do Olho/química , Proteínas do Olho/metabolismo , Imageamento Tridimensional , Bicamadas Lipídicas/metabolismo , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana/metabolismo , Fosfolipídeos/química , Fosfolipídeos/metabolismo
16.
Endoscopy ; 34(7): 546-50, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12170407

RESUMO

BACKGROUND AND STUDY AIMS: Patients who have undergone endoscopic sphincterotomy (ES) are usually left to fast for arbitrary reasons until they are examined on the following day. The aim of this study was to check whether this systematic fasting after ES is actually justified. PATIENTS AND METHODS: A blinded randomized prospective study, involving 146 patients, was carried out from January 1999 to September 2001. All patients undergoing biliary and/or pancreatic endoscopic sphincterotomy during this period were randomly allocated to one of two groups: group 1 patients were re-fed 4 hours after ES, and the group 2 patients were only re-fed 24 hours after the procedure. These two groups were comparable for clinical and procedural data except for stenting. RESULTS: Eight patients in group 1 (11 %) and 26 patients in group 2 (37 %) suffered from abdominal pain which resolved with analgesic drug treatment (P = 0.01). Eight patients in the first group(11 %) and five patients in the second group (7 %) had to be given major opiate analgesics (P = 0.56). Refeeding resulted in abdominal pain in five patients in group 1 and 13 in group 2 (P = 0.04). The serum amylase and lipase levels increased significantly after refeeding in group 1, but lipasemia did not increase significantly in group 2. No significant differences in post-ES complications were observed between the two groups. The mean hospital stay was significantly shorter in group 1 : 2.6 days on average, vs. 3.8 days in group 2 (P = 0.03). CONCLUSIONS: In the absence of any perforation of the digestive tract or immediate severe acute pancreatitis, early refeeding could be helpful to decrease pain and shorten the hospital stay in patients who have undergone endoscopic sphincterotomy.


Assuntos
Ductos Biliares/patologia , Colangiopancreatografia Retrógrada Endoscópica , Colelitíase/cirurgia , Endoscopia do Sistema Digestório , Jejum , Cuidados Pós-Operatórios , Amilases/sangue , Constrição Patológica , Humanos , Tempo de Internação , Lipase/sangue , Dor Pós-Operatória/prevenção & controle , Estudos Prospectivos
17.
Int J Colorectal Dis ; 17(2): 123-8, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12014420

RESUMO

BACKGROUND AND AIMS: This study determined correlations of clinical and manometric features with those of anal endosonography (AES). PATIENTS AND METHODS: Between 1996 and 1999 we examined 58 patients suffering from anal incontinence (AI) by AES using a linear probe and anorectal manometry following a standardized protocol. RESULTS: Twelve of the 58 patients (21%) had a history of anal surgery. Of the 40 women who had under-gone at least one vaginal delivery 22 (55%) sustained an obstetric tear and 12 (30%) required forceps for delivery. A perineal descent was observed in 24 of 32 women with AI (75%) and urinary incontinence in 24 of 44 (54%). An anal sphincter defect was diagnosed in 45 of the 58 patients (77%). The internal anal sphincter defects occurring in 42 patients (72%) were significantly associated with a decrease in the resting anal pressure. The external anal sphincter defects occurring in 33 patients (57%) were significantly associated with a decrease in the voluntary anal contraction. CONCLUSION: Considering AES and manometric findings, a good correlation was observed between internal sphincter defect and the resting anal pressure and between external sphincter defects and the voluntary anal contraction. AI is usually associated with a global perineal insufficiency requiring special attention in terms of both training and medical management.


Assuntos
Canal Anal/diagnóstico por imagem , Endossonografia , Incontinência Fecal/diagnóstico por imagem , Adulto , Idoso , Canal Anal/fisiopatologia , Incontinência Fecal/fisiopatologia , Feminino , Humanos , Masculino , Manometria , Pessoa de Meia-Idade
18.
Ann Chir ; 126(4): 296-301, 2001 May.
Artigo em Francês | MEDLINE | ID: mdl-11413807

RESUMO

BACKGROUND: Postoperative recurrences of Crohn's disease (CD) has been widely investigated in previous studies. Nevertheless, the risk factors for CD recurrence in patients presenting with intestinal stenosis are not clearly identified. PATIENTS AND METHOD: Thirty consecutive patients out of a cohort of 134 patients with CD presented with an intestinal stenosis diagnosed between 1995 and 1999. Epidemiological, clinical, and therapeutic data were carefully recorded. A univariate analysis followed by stepwise descending discriminant analysis was performed. RESULTS: Sixteen patients (53%) underwent surgery, six received steroid therapy, eight were given antibiotics, and seven took immunosuppressive drugs. The mean follow-up after medical or surgical management was 2.8 years. Thirteen patients (43%) had CD relapse during the follow-up. Considering the univariate analysis, the existence of a previous appendectomy and the persistence of tobacco consumption were significantly associated with the risk of CD relapse during the follow-up. The stepwise descending discriminant analysis identified three independant factors: tobacco consumption (p = 0.007), previous appendicectomy (p = 0.04) and duration of the follow-up (p = 0.02). CONCLUSION: The CD relapse after the management of small bowel stenosis occurred in 43% of the patients within a mean follow-up of 2.8 years. The significant factors associated with the risk of CD relapse were tobacco consumption, previous appendectomy and duration of the follow-up.


Assuntos
Doença de Crohn/complicações , Enteropatias/cirurgia , Fumar/efeitos adversos , Adulto , Antibacterianos/uso terapêutico , Apendicectomia , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Doença de Crohn/patologia , Feminino , Seguimentos , Humanos , Imunossupressores , Enteropatias/etiologia , Masculino , Recidiva , Fatores de Risco , Esteroides/uso terapêutico
19.
Ultramicroscopy ; 87(4): 187-97, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11334166

RESUMO

The lines of a large group of sinograms of projections with random orientation can be submitted to correspondence analysis. Since the number of samples per line is small, a small matrix is accumulated which is quick to orthogonalise. In the eigenvector space, the lines of a sinogram are represented by points describing a closed trajectory. Two trajectories of different sinograms intersect in the position of their common line. Determining where two trajectories cross each other is a problem of minimum chi2 distance in the space of 5-7 eigenvectors. An algorithm to determine common lines has been implemented and tested with phantom projections oriented at random, and corrupted with noise. The images were simulating a set collected with the two exposures technique, already proposed by the authors for three dimensional reconstruction from random projections. The preliminary models obtained with the new algorithm have been refined by a projection matching based on trajectories. This step requires determining which trajectory, in a set representing computed projections, matches at best with that of an experimental projection. This is a problem of minimum distance in a space with low dimensionality. The present algorithms, based on chi2 distances, run much faster than those based on correlation analysis and the quality of the reconstructed phantoms looks satisfactory.

20.
Bioinformatics ; 17(1): 58-62, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11222262

RESUMO

MOTIVATION: A number of macromolecular assemblies are being reconstructed in 3D from electron micrographs. The analysis yields a 3D matrix representing the protein density map. In reconstruction processes and in comparing the results of different experiments, it is often necessary to obtain all models oriented the same way in three dimensions. The problem is not trivial since there exist no 3D counterpart of correlation analysis used for 2D images. It is usually solved by time consuming trial and error algorithms. RESULTS: 3D density distributions can be brought to a 'canonical' orientation. The tensor of inertia of the distribution is determined and its eigenvectors are oriented along the coordinate axes. The method is fast and essentially free of reference. It is suitable for structures whose inertial axes do not completely degenerate as they do in icosahedral viruses or if symmetry is cubic. Applications are presented for asymmetric objects and for molecules possessing symmetry axes higher than twofold. IMPLEMENTATION: The implementation simply requires the accumulation of the inertial tensor and its diagonalisation. Volume data rotation has been already illustrated in this journal by the authors.


Assuntos
Modelos Moleculares , Software , Algoritmos , Biologia Computacional , Processamento de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Substâncias Macromoleculares , Microscopia Eletrônica
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