Easy preoperative planning of deeply located brain lesions using external skin reference and 3-Dimensional surface MRI

Open skull surgery of deeply located intracerebral lesions requires precise determination of the treatment area in 3-dimensional (3-D) space. 3-D MRI can give important additional information in presurgical determination of the surgical approach to the target, taking into account highly functional brain areas and important vascular structures. The day before surgery, a grid composed of 9 tubings intersecting at 90° at 1 cm intervals and filled with a Q1SO4 solution is firmly attached to the skin of the patient’s head in the presumed region of the craniotomy. A 3-D turbo-FLASH sequence is then performed in the sagittal plane after intravenous Gd-DOTA injection on a IT Magnetom. 3-D surface reconstruction of the cortical gyri and sulci is performed. Once the gyri are identified, the 3-D program is then implemented in order to perform a color display of the cortical veins and of the tumor boundaries. The surgical access is then chosen by the surgeon, taking into account highly functional areas. Finally, the boundaries of the tumor are projected on the cortex reconstruction and on the external reference placed on the skin. The entry place for surgery as well as the size of craniotomy are drawn on the skin and the tubed grid is removed. The accuracy of this method tested in 9 patients with deeply located brain tumors or arteriovenous malformations was very satisfactory. In daily practice, this method is a valuable technique providing important clinical information in determining the shortest and safest way through the brain tissue, decreasing possible functional deficit and reducing craniotomy size in cases of difficult to access deep brain areas. Our method does not require a stereotactic frame permanently fixed to the head of the patient during surgery. © 1994 S. Karger AG, Basel.

Métabolisme des glucocorticoïdes dans le poumon murin en développement : la voie surrénalienne

Lorsqu’une femme est à risque d’accoucher prématurément, des glucocorticoïdes lui seront administrés afin d’accélérer la maturation pulmonaire du bébé. Après la naissance, différents protocoles peuvent être mis en place pour aider l’enfant à respirer dont l’administration du surfactant et la ventilation. Les glucocorticoïdes ont un effet positif sur la maturation pulmonaire. Par contre, ils nuisent au processus de la septation après la naissance. Les glucocorticoïdes retrouvés dans le poumon en développement peuvent provenir de deux sources, soit de la voie classique de la synthèse des glucocorticoïdes par les surrénales, soit des gènes exprimés dans le poumon. Les sites d’expression des gènes codant pour les enzymes de la synthèse des glucocorticoïdes dans le poumon sont inconnus ainsi que le gène de la 20α-hydroxystéroïde déshydrogénase (20α-HSD). Cette dernière inactive le substrat et le produit de la 21-hydroxylase. Des poumons de fœtus de souris au jour de gestation 15,5, 17,5 et 19,5 ainsi que de souriceaux âgés de 0, 5 et 15 jours ont été utilisés pour des hybridations in situ. Cette étude a montré qu’avant la naissance, l’ARNm de la 21-hydroxylase est situé au niveau des cellules épithéliales distales alors que l’ARNm de la 20α-HSD se retrouve plutôt au niveau des capillaires. Les gènes de la 21-hydroxylase et de la 20α-HSD sont exprimés dans les cellules épithéliales proximales ainsi que dans les cellules endothéliales de veines dans la période entourant la naissance. À la fin du stade sacculaire et pendant le stade alvéolaire, le gène de la 21-hydroxylase est exprimé seulement dans les septa et les parois minces tout comme le gène de la 20α-HSD sauf dans le stade alvéolaire où il n’y avait pas de signal significatif. Ainsi, ces résultats suggèrent que la 20α-HSD pourrait participer au contrôle du niveau d’activité de la 21-hydroxylase en modulant la disponibilité de son substrat.

Contact Force in Atrial Fibrillation: Role of Atrial Rhythm and Ventricular Contractions: Co-Force Atrial Fibrillation Study

In an experimental model, variable and intermittent contact force (CF) resulted in a significant decrease in lesion volume. In humans, variability of CF during pulmonary vein isolation has not been characterized. Methods and Results-In 20 consecutive patients undergoing CF-guided circumferential pulmonary vein isolation, 914 radiofrequency applications (530 in sinus rhythm and 384 in atrial fibrillation) were analyzed. The variability of the 60% CF range (CF60%) was 17 ± 9.6 g. Hundred seventy-one (19%) applications were delivered with constant, 717 (78%) with variable, and 26 (3%) with intermittent CF. The mean CF and force-time integral were significantly higher during applications with variable than with intermittent or constant CF. There was no significant difference in CF variability, CF60% variability, and force-time integral between applications delivered in sinus rhythm and atrial fibrillation. The main reasons for CF variability were systolo-diastolic heart movement (29%) and respiration (27%). In 10 additional patients, during adenosine-induced atrioventricular block, the minimum CF significantly increased at 19 sites (5.3 ± 4.4 versus 13.4 ± 5.9 g; P < 0.001) and at 16 sites intermittent or variable CF became constant. At only 1 site systolo-diastolic movement remained the main reason for variable CF. Conclusions-CF during pulmonary vein isolation remains highly variable despite efforts to optimize contact. CF and CF parameters were similar during sinus rhythm and atrial fibrillation. The main reasons for CF variability are systolodiastolic heart movement and respiration. The systolo-diastolic peaks and nadirs of CF are because of ventricular contractions at the large majority of pulmonary vein isolation sites.

Subfascial endoscopic perforator surgery (SEPS) in chronic venous insufficiency. A 14 years experience

Introduction. Subfascial Endoscopic Perforator Surgery (SEPS) enables the direct visualization and section of perforating veins. Morbidity and duration of hospitalization are both less than with conventional open surgery (Linton’s or Felder’s techniques). Patients and methods. A total of 322 legs from 285 patients with a mean age of 56 years (range 23-90) were treated at our Department from May 1996 to January 2010. In 309 cases, an endoscope (ETM Endoskopische Technik GmbH, Berlin, Germany) was introduced through a transverse incision approximately 1.5 cm in length and 10 cm from the tibial tuberosity, as with Linton’s technique. A spacemaker balloon dissector for SEPS, involving a second incision 6 cm from the first, was used in only 13 cases. Results. The procedure used in each case was decided on the basis of preoperative evaluation. SEPS and stripping were performed in 238 limbs (73.91%), SEPS and short stripping in 7 limbs (2.17%), SEPS and crossectomy in 51 limbs (15.84%), and SEPS alone in 26 limbs (8.07%). 103 patients presented a total of 158 trophic ulcers; the healing time was between 1 and 3 months, with a healing rate of 82.91% after 1 month and 98.73% after 3 months. Conclusion. Subfascial ligature of perforating veins is superior to sclerotherapy and minimally invasive suprafascial treatment for the treatment of CVI. It is easy to execute, minimally invasive and has few complications.

Oclusão percutânea do apêndice auricular esquerdo e estrutura auricular: efeito na função mecânica e endócrina auricular

Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Área de especialização: Intervenção Cardiovascular.

Caractérisation des effets de l’hyperglycémie chronique dans la choroïde d’yeux diabétiques

But: Le diabète est un problème important de santé publique et la complication oculaire la plus commune est la rétinopathie diabétique (RD). Certaines études indiquent que la choroïde des patients diabétiques est affectée sans signe apparent de RD. Notre hypothèse est que l’élévation du stress oxydant liée à l’hyperglycémie chronique affecte la fonction choroïdienne à un stade précoce de la RD. Nous proposons d’étudier la glycolyse, le métabolisme mitochondrial, le stress nitrosatif et la méthylation de l’ADN ainsi que de caractériser les modifications histologiques dans la choroïde diabétique. Méthodes: L’expression des gènes/protéines associés à la glycolyse, au métabolisme mitochondrial et à la production de l’oxyde nitrique a été comparée par profilage génique et immunobuvardage Western entre les choroïdes saines et diabétiques. Les niveaux globaux de méthylation et d’hydroxyméthylation de l’ADN ont été quantifiés par immunoslot blot et HPLC-MS/MS dans ces tissus. Enfin, des coupes tissulaires d’yeux de donneurs sains ou diabétiques avec RD non proliférante (RDNP) ou proliférante (RDP) ont été colorées au trichrome de Masson et au Weigert. L’épaisseur de la choroïde et de la membrane de Bruch, ainsi que la densité et le diamètre des vaisseaux sanguins choroïdiens ont été analysés. Résultats: Nos résultats montrent une dérégulation de l’expression de certains transcrits de la choroïde diabétique, mais peu de différences au niveau de l’expression protéique des cibles validées. Le niveau global de méthylation de l’ADN est similaire entre les donneurs sains et diabétiques. Nos analyses histologiques démontrent une diminution de l’épaisseur de la choroïde et une dégénérescence des choriocapillaires et des veines/veinules chez les donneurs diabétiques atteints de RDP. Conclusions: L’étude de la choroïde est importante, car l’atteinte de ce tissu a de graves répercussions sur la fonction rétinienne. L’identification de cibles dans la choroïde ouvre de nouvelles perspectives pour un traitement préventif de la RD.

Características clínicas y epidemiológicas del neumotórax en personas de 18 años y más: Hospital Vicente Corral Moscoso y Teófilo Dávila de Machala, 2007-2011

Se realizó un estudio descriptivo- retrospectivo desde enero de 2007 a diciembre del 2011. El universo estuvo constituido por los pacientes de 18 años y más con diagnóstico de Neumotórax, internados en los departamentos de cirugía del Hospital Regional Vicente Corral Moscoso y Hospital Teófilo Dávila. Para el levantamiento de la información se utilizó un formulario previamente diseñado. Los datos se transcribieron de las historias clínicas a los formularios respectivos. Resultados: Se incluyeron 73 pacientes del HTD y 52 del HVCM, el neumotórax de mayor prevalencia fue el traumático con el 85.6% de los casos, izquierdo en el 54.4%; las características clínicas de mayor relevancia fueron: dolor moderado 40.8%; taquicardia 15.2%; desviación de la tráquea hacia la derecha 32.8%; distención de las venas del cuello 38.4%; hipersonoridad 76.8%; murmullo vesicular disminuido 80%; disnea 99.2%; cianosis 22.4%; los método diagnósticos presentaron la siguiente prevalencia: radiografía de tórax 100%; tomografía 27.2% y resonancia en el 0.8% de los casos; el tratamiento fue en el 16% toracocentesis con aspiración de aguja y en el 100% tubo de tórax. La media de días de hospitalización fue de 5 días y la mortalidad fue del 10.4%.- Conclusiones: Se registraron diferencias estadísticamente significativas entre ambas instituciones en las características clínicas en cuanto a la procedencia, intensidad del dolor, frecuencia cardiaca, murmullo vesicular disminuido y presentación de cianosis. Además se evidencia una alta mortalidad.au

Large-scale dynamic hydrofracturing, healing and fracture network characterization

Permeability of a rock is a dynamic property that varies spatially and temporally. Fractures provide the most efficient channels for fluid flow and thus directly contribute to the permeability of the system. Fractures usually form as a result of a combination of tectonic stresses, gravity (i.e. lithostatic pressure) and fluid pressures. High pressure gradients alone can cause fracturing, the process which is termed as hydrofracturing that can determine caprock (seal) stability or reservoir integrity. Fluids also transport mass and heat, and are responsible for the formation of veins by precipitating minerals within open fractures. Veining (healing) thus directly influences the rock’s permeability. Upon deformation these closed factures (veins) can refracture and the cycle starts again. This fracturing-healing-refacturing cycle is a fundamental part in studying the deformation dynamics and permeability evolution of rock systems. This is generally accompanied by fracture network characterization focusing on network topology that determines network connectivity. Fracture characterization allows to acquire quantitative and qualitative data on fractures and forms an important part of reservoir modeling. This thesis highlights the importance of fracture-healing and veins’ mechanical properties on the deformation dynamics. It shows that permeability varies spatially and temporally, and that healed systems (veined rocks) should not be treated as fractured systems (rocks without veins). Field observations also demonstrate the influence of contrasting mechanical properties, in addition to the complexities of vein microstructures that can form in low-porosity and permeability layered sequences. The thesis also presents graph theory as a characterization method to obtain statistical measures on evolving network connectivity. It also proposes what measures a good reservoir should have to exhibit potentially large permeability and robustness against healing. The results presented in the thesis can have applications for hydrocarbon and geothermal reservoir exploration, mining industry, underground waste disposal, CO2 injection or groundwater modeling.

Effect of portal hypertension in the small bowel: an endoscopic approach

BACKGROUND AND AIM: The effects of portal hypertension in the small bowel are largely unknown. The aim of the study was to prospectively assess portal hypertension manifestations in the small bowel. METHODS: We compared, by performing enteroscopy with capsule endoscopy, the endoscopic findings of 36 patients with portal hypertension, 25 cirrhotic and 11 non-cirrhotic, with 30 controls. RESULTS: Varices, defined as distended, tortuous, or saccular veins, and areas of mucosa with a reticulate pattern were significantly more frequent in patients with PTH. These two findings were detected in 26 of the 66 patients (39%), 25 from the group with PTH (69%) and one from the control group (3%) (P < 0.0001). Among the 25 patients with PTH exhibiting these patterns, 17 were cirrhotic and 8 were non-cirrhotic (P = 0.551). The presence of these endoscopic changes was not related to age, gender, presence of cirrhosis, esophageal or gastric varices, portal hypertensive gastropathy, portal hypertensive colopathy, prior esophageal endoscopic treatment, current administration of beta-blockers, or Child-Pugh Class C. More patients with these endoscopic patterns had a previous history of acute digestive bleeding (72% vs. 36%) (P = 0.05). Active bleeding was found in two patients (5.5%). CONCLUSIONS: The presence of varices or areas of mucosa with a reticulate pattern are manifestations of portal hypertension in the small bowel, found in both cirrhotic and non-cirrhotic patients. The clinical implications of these findings, as regards digestive bleeding, are uncertain, although we documented acute bleeding from the small bowel in two patients (5.5%).

A New Mouse Model That Spontaneously Develops Chronic Liver Inflammation and Fibrosis

Here we characterize a new animal model that spontaneously develops chronic inflammation and fibrosis in multiple organs, the non-obese diabetic inflammation and fibrosis (N-IF) mouse. In the liver, the N-IF mouse displays inflammation and fibrosis particularly evident around portal tracts and central veins and accompanied with evidence of abnormal intrahepatic bile ducts. The extensive cellular infiltration consists mainly of macrophages, granulocytes, particularly eosinophils, and mast cells. This inflammatory syndrome is mediated by a transgenic population of natural killer T cells (NKT) induced in an immunodeficient NOD genetic background. The disease is transferrable to immunodeficient recipients, while polyclonal T cells from unaffected syngeneic donors can inhibit the disease phenotype. Because of the fibrotic component, early on-set, spontaneous nature and reproducibility, this novel mouse model provides a unique tool to gain further insight into the underlying mechanisms mediating transformation of chronic inflammation into fibrosis and to evaluate intervention protocols for treating conditions of fibrotic disorders.

Trombose venosa profunda em idade pediátrica – estudo retrospetivo de 10 anos

Introdução e Objetivos: A trombose venosa profunda (TVP) e o tromboembolismo pulmonar são os componentes do tromboembolismo venoso (TEV) que, embora infrequente, é uma entidade emergente na pediatria. Apresentamos uma casuística cujo objetivo é a avaliação dos aspetos mais relevantes da TVP em idade pediátrica e da sua abordagem terapêutica. Metodologia: Revisão retrospetiva descritiva dos processos dos doentes internados na última década com o diagnóstico de TVP no Serviço de Pediatria da ULSAM. Resultados: Identificaram-se seis doentes, cinco deles do sexo feminino. A mediana de idades foi 17 anos. O edema do membro afetado esteve sempre presente e o segmento venoso mais atingido foi o ileofemoral (2/6). Houve concomitância de pelo menos dois fatores de risco adquiridos em três doentes, sendo o mais frequente o contracetivo oral combinado. Foi excluída trombofilia hereditária em cinco doentes mas ainda aguardamos o resultado do estudo de um doente. O tempo médio de tratamento foi de 9,8 meses. Discussão e Conclusão: A TVP na criança tem sido reconhecida como uma patologia rara, mas importante causa de morbilidade. A maior incidência de TVP foi documentada na adolescência com compromisso do membro inferior, tal como referido na literatura. Verificamos uma conjugação de fatores de risco que, provavelmente, se potenciaram entre si levando à ocorrência do TEV e colocamos a possibilidade do Pediatra se estar a deparar com uma nova realidade anteriormente excluída do atendimento pediátrico. O aumento na incidência desta patologia levanta a questão do acréscimo de risco trombótico nos adolescentes do sexo feminino devido à utilização de contracetivos orais combinados. Salientamos a importância de um consenso nacional no diagnóstico, tratamento e prevenção desta entidade em Pediatria.

Geologia, petrologia, geocronologia e mineralizações sulfetadas do complexo ézio, província mineral de carajás, Brasil

Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, Pós-Graduação em Geologia, 2015.

Sequestro pulmonar : trabalho de revisão

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Estimation of leaf area in grapevine cv. Syrah using empirical models

Aiming to obtain empirical models for the estimation of Syrah leaf area a set of 210 fruiting shoots was randomly collected during the 2013 growing season in an adult experimental vineyard, located in Lisbon, Portugal. Samples of 30 fruiting shoots were taken periodically from the stage of inflorescences visible to veraison (7 sampling dates). At the lab, from each shoot, primary and lateral leaves were separated and numbered according to node insertion. For each leaf, the length of the central and lateral veins was recorded and then the leaf area was measured by a leaf area meter. For single leaf area estimation the best statistical models uses as explanatory variable the sum of the lengths of the two lateral leaf veins. For the estimation of leaf area per shoot it was followed the approach of Lopes & Pinto (2005), based on 3 explanatory variables: number of primary leaves and area of the largest and smallest leaves. The best statistical model for estimation of primary leaf area per shoot uses a calculated variable obtained from the average of the largest and smallest primary leaf area multiplied by the number of primary leaves. For lateral leaf area estimation another model using the same type of calculated variable is also presented. All models explain a very high proportion of variability in leaf area. Our results confirm the already reported strong importance of the three measured variables (number of leaves and area of the largest and smallest leaf) as predictors of the shoot leaf area. The proposed models can be used to accurately predict Syrah primary and secondary leaf area per shoot in any phase of the growing cycle. They are inexpensive, practical, non-destructive methods which do not require specialized staff or expensive equipment.

Oral thearubigins do not protect against acetaminopheninduced hepatotoxicity in mice

Purpose: To investigate the potential protective effect of oral repeated doses of thearubigins against acetaminophen-induced hepatotoxicity in mice. Methods: Mice were randomly divided into six groups (n=8) and administered the following: Control group (saline), acetaminophen group (saline), N-acetylcysteine group (500 mg/kg/day), and thearubigins groups (60, 70, 100 mg/kg/day). The drugs were given orally by gavage for seven days. On day 7, 1 h after the last dose of treatment, the mice (except control group) were given a single dose of acetaminophen (n-acetyl-p-aminophenol, APAP) orally by gavage (350 mg/kg) and then sacrificed 4 h post-APAP intake. Blood was collected for biochemical measurements and their liver were subjected to biochemical and histopathological assessment. Results: The acetaminophen group showed significant increases (p < 0.001) in serum alanine aminotransferase level, hepatic cytochrome P2E1 level, and serum and hepatic malondialdehyde levels. Moreover it showed significant decrease (p < 0.001) in serum and hepatic glutathione levels. Morphologically, the liver sections showed cellular necrosis, vacuolization, and degeneration around the centrilobular veins. Pretreatment with N-acetylcysteine reversed all acetaminophen-induced changes (p < 0.001 for all biomarkers except for hepatic MDA (p = 0.014) while pretreatment with thearubigins failed to reverse any of them. Conclusion: Oral repeated doses of thearubigins failed to protect against acetaminophen-induced hepatotoxicity in mice and didn\'t affect hepatic cytochrome P2E1 level.