Single-center experience in the treatment of visceral artery aneurysms

Background: Visceral artery aneurysms (VAAs), although rare, represent a life-threatening disease with high mortality rates. With the more frequent use of diagnostic tests, there has been an incidental detection of these lesions which are mostly asymptomatic. It follows that surgeons are increasingly called to decide on the most appropriate management of VAAs between an open surgical or endovascular approach and among the different endovascular options currently available. The aim of this retrospective study was to evaluate the results of open surgery and interventional endovascular strategies of visceral artery aneurysms with respect to technical success, therapy-associated complications, and postinterventional follow-up in the elective and emergency situation. Methods: From January 1992 to January 2017, 125 open surgical or endovascular interventions for VAA were performed at our institution. Once the VAA was diagnosed and the indication for treatment was assessed, the preoperative diagnostic work-up consisted of contrast computed tomography (CT) or magnetic resonance imaging (MRI) and, in some patients, digital subtraction angiography. Follow-up included clinical and duplex ultrasound scan (DUS) and contrast-enhanced ultrasound to assess the treated vessel patency and organ perfusion after 1, 6, and 12 months, and yearly thereafter. CT or MRI controls were also performed at 1 year of follow-up and only when DUS was not diagnostic or showed a complication thereafter. After the first 5 years of follow-up, the status of the patient was obtained by a structured telephone survey. Results: The treatment option was endovascular in 56 of 125 cases (44.8%). Technical success was 98.3%. In one case, the procedure was interrupted for the extensive dissection of the afferent vessel. Twenty-six patients were treated by coil embolization while 29 with covered stenting. The endovascular approach was in emergency in two cases (3.6%). In the endovascular group, mortality was nil. Complications occurred in 5 cases (8.9%): 1 subacute intestinal ischemia caused by superior mesenteric artery dissection, 2 aneurysm reperfusion, 1 stent thrombosis, and 1 massive splenic hematoma. In 69 (55.2%) cases, surgical treatment was preferred, with 24 VAA resections and 45 arterial reconstructions. In 20 cases (29%), open surgery was performed in emergency conditions. In the surgical group, 8 emergency patients (40%) died intraoperatively. The mortality after elective surgical interventions was nil. Complications after surgery were 4 graft late thrombosis (5.8%): asymptomatic in three cases and requiring splenectomy in one. Conclusions: There is no overall consensus regarding the indications for treatment of VAA. Currently in emergent setting, the endovascular approach should be considered as the first choice because of its reduced invasiveness, faster way to access and bleeding control; this accounts for the lower morality of the interventional therapy than open surgery. Endovascular approach is effective for elective repair of VAAs, but procedure-related complications may occur in a not negligible number of patients. Given comparable mortality rates and low procedure-related complication rate, surgical approach still has space in the elective management of VAAs, especially for aneurysms unsuitable or challenging for the endovascular option in patients with low surgical risk. The size, location, and morphology of VAAs, systemic or local comorbidities, and specific anatomical situations such as previous abdominal surgery should dictate treatment choice

Approaches and tools to manipulate the carbonate chemistry

Although the chemistry of ocean acidifi cation is very well understood (see chapter 1), its impact on marine organisms and ecosystems remains poorly known. The biological response to ocean acidifi cation is a recent field of research, the fi rst purposeful experiments have only been carried out as late as the 1980s (Agegian, 1985) and most were not performed until the late 1990s. The potentially dire consequences of ocean acidifi cation have attracted the interest of scientists and students with a limited knowledge of the carbonate chemistry and its experimental manipulation. Perturbation experiments are one of the key approaches used to investigate the biological response to elevated p(CO2). Such experiments are based on measurements of physiological or metabolic processes in organisms and communities exposed to seawater with normal and altered carbonate chemistry. The basics of the carbonate chemistry must be understood to perform meaningful CO2 perturbation experiments (see chapter 1). Briefl y, the marine carbonate system considers € CO2 ∗(aq) [the sum of CO2 and H2CO3], € HCO3 −, € CO3 2−, H+, € OH− , and several weak acid-base systems of which borate-boric acid (€ B(OH)4 − , B(OH)3) is the most important. As discussed by Dickson (chapter 1), if two components of the carbonate chemistry are known, all the other components can be calculated for seawater with typical nutrient concentrations at given temperature, salinity, and pressure. One of the possible pairs is of particular interest because both components can be measured with precision, accuracy, and are conservative in the sense that their concentrations do not change with temperature or pressure. Dissolved inorganic carbon (DIC) is the sum of all dissolved inorganic carbon species while total alkalinity (AT) equals € [HCO3 − ] + 2 € [CO3 2− ] + € [B(OH)4 − ] + € [OH− ] - [H+] + minor components, and refl ects the excess of proton acceptors over proton donors with respect to a zero level of protons (see chapter 1 for a detailed defi nition). AT is determined by the titration of seawater with a strong acid and thus can also be regarded as a measure of the buffering capacity. Any changes in any single component of the carbonate system will lead to changes in several, if not all, other components. In other words, it is not possible to vary a single component of the carbonate system while keeping all other components constant. This interdependency in the carbonate system is important to consider when performing CO2 perturbation experiments. To adjust seawater to different p(CO2) levels, the carbonate system can be manipulated in various ways that usually involve changes in AT or DIC. The goal of this chapter is (1) to examine the benefi ts and drawbacks of various manipulation methods used to date and (2) to provide a simple software package to assist the design of perturbation experiments

An evaluation of curriculum-related specialties in grades five and six

Thesis (Ed.M.)--Boston Universit

Estandarización micrográfica de especies de Baccharis L. (Asteraceae)

Controversies still exist regarding the differentiation of some Baccharis sect. Caulopterae species known as “carqueja”. In the present work we studied anatomically five of these species: Baccharis articulata (Ba), Baccharis crispa (Bc), Baccharis gaudichaudiana (Bg), Baccharis microcephala (Bm) and Baccharis trimera (Bt). Ba and Bc are considered official in Argentinean Pharmacopeia and Bt in the Brazilian Pharmacopeia. Bg and Bm are considering possible substitutes. The qualitative and quantitative variables for each one were determined, emphasizing the importance of anatomic characters as taxonomically useful. Analytical micrographs of the studied species were elaborated as reference standards for quality control of the raw drug.Aún existen controversias con respecto a la correcta diferenciación de las especies de Baccharis de la sección Caulopterae conocidas como “carqueja”. En este trabajo se estudió anatómicamente a cinco de estas especies: Baccharis articulata (Ba), Baccharis crispa (Bc), Baccharis gaudichaudiana (Bg), Baccharis microcephala (Bm) y Baccharis trimera (Bt). Las especies Ba y Bc son consideradas oficiales en la Farmacopea Argentina y Bt en la Farmacopea Brasileña. Bg y Bm son consideradas posibles sustituyentes de las anteriores. Se determinaron las variables cualitativas y cuantitativas para cada una, resaltando la importancia de la anatomía en la obtención de caracteres taxonómicos para poder diferenciarlas. Con los datos obtenidos se elaboraron las micrografias analíticas de las especies estudiadas, para que puedan ser utilizadas como patrones de referencia para el control de calidad de la droga cruda.Fil: Rodriguez, María Victoria. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gattuso, Susana Julia. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Gattuso, Martha Ana. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentin

Biological control of air-sea CO₂ fluxes: effect of photosynthetic and calcifying marine organisms and ecosystems

A simple expression enables prediction of the effect of photosynthetic and calcifying systems on air-sea CO2 exchange at all spatial scales (from organism to ecosystem). Input data are: gross primary production (Pg), respiration (R), net calcification (G) and the ratio of CO2 released to CaCO3 precipitated ( psi ); the output is the amount of dissolved inorganic carbon (FCO2 which needs to be exchanged with the atmosphere to balance biologically mediated changes in the concentration of dissolved inorganic carbon in an open sea water system: FCO2 = -Pg + R + psi G. Coral reef data were used in the model to illustrate the relative influence of organic and inorganic carbon metabolism on ocean-atmosphere CO2 cycling. A coral reef comprised of calcareous and non-calcareous organisms can be shown to act as a sink for atmospheric CO2 when excess (= net) production is high and CaCO3 precipitation is low. These characteristics are not typical of actively developing reef systems which typically exhibit a nearly balanced organic carbon metabolism (Pg/R similar to 1) and relatively high rates of calcification. In these circumstances, reef communities can be expected to cause CO2 evasion to the atmosphere. This prediction is confirmed by the only existing measurement of air-sea CO2 flux in a coral reef system

Estudio anatómico de Baccharis grisebachii Hieron. (Asteraceae). Usada en la medicina tradicional de la Provincia de San Juan, Argentina

Baccharis grisebachii Hieron., commonly known as “quilchamali”, is a bushy plant that lives in the high mountains of Argentina and southern Bolivia. The infusion or decoction of aerial parts is used in the traditional medicine of San Juan province, Argentina, to treat gastric ulcers, digestive problems, and as antiseptic and wound healing in humans and horses. The aim of this study is to analyze the anatomical characters of B. grisebachii for specific identification and quality control. The results show that the leaf blade is ericoid with a dorsiventral mesophyll, and epidermis has a smooth and thick cuticle. The stomata are anomocytic. In both epidermis there are two types of hairs, not glandular and glandular. Adult stems show secondary structures. The root shows 1 - 2 rows of pericyclic cells and an endodermis. B. grisebachii shows xeromorphic anatomic characters. The structural characters provide micrographic reference standards, useful for quality control at the crude drug stage.Baccharis grisebachii Hieron. conocida comúnmente como “quilchamali” es una planta arbustiva que vive en las altas montañas de la Argentina y el sur de Bolivia. La infusión o decoción de las partes aéreas es utilizada en la medicina tradicional de la provincia de San Juan, Argentina, para tratar las úlceras gástricas, problemas digestivos y como cicatrizante de heridas y antiséptica en humanos y equinos. El objetivo de este estudio es analizar las características anatómicas de B. grisebachii útiles en la identificación y control de calidad de la especie. Los resultados muestran que la hoja es ericoide con mesofilo dorsiventral y tiene una epidermis con una cutícula gruesa y lisa. Los estomas son anomocíticos. En ambas epidermis se encuentran dos tipos de pelos, no glandulares y glandulares. En tallos adultos se hace evidente una estructura secundaria y en la raíz se observan 1-2 hileras de células pericíclicas y la endodermis. B. grisebachii muestra caracteres anatómicos xeromórficos. Los caracteres estructurales enunciados proporcionan patrones de referencia micrográficos, útiles para el control de calidad de la droga cruda.Fil: Hadad, Martín Ariel. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Gattuso, Susana Julia. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gattuso, Martha Ana. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Feresin, Gabriela Egly. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Tapia, Aníbal Alejandro. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentin

Évaluation quantitative de l'impact du tutorat maître-élève sur la réussite académique (validation du projet Odyssée)

Titre de la couv."La présente recherche a été subventionnée par l'Association des collèges privés du Québec dans le cadre du Programme de recherche et d'expérimentation"Titre de l'écran-titre (visionné le 1er avril 2008).Également disponible en format papier.Bibliogr

Models of intermodal node representation

This paper analyses three different approaches of supply representation for intermodal nodes and proposes some functional and topological models for the representation of ports and Freight Villages. Besides in the paper functional and topological representation of container port and freight village are proposed. Further research is directed to the specification and calibration of cost functions, useful for cost estimation for different components of node network, with a view to facilitate the analyses of freight mobility on multimodal large networks

Évaluation quantitative de l'impact du tutorat maître-élève sur la réussite académique (validation du projet Odyssée) rapport de recherche ACPQ /

Titre de la couv."La présente recherche a été subventionnée par l'Association des collèges privés du Québec dans le cadre du Programme de recherche et d'expérimentation"Titre de l'écran-titre (visionné le 1er avril 2008).Également disponible en format papier.Bibliogr