Chum Research Centre

MATERIALS AND METHODS: Angiographic and pathologic changes were investigated in canine bilateral venous pouch carotid aneurysms embolized with gelatin sponges with or without previous endothelial denudation, a procedure that can prevent recanalization. To assess a potential role of MMP-9, messenger RNA (mRNA) and protein were compared in denuded and nondenuded aneurysms 4, 7, and 14 days after embolization. To assess if MMP-9 is essential to arterial recanalization, transmyocardial angiography and pathologic findings were compared 14 days after carotid occlusion with platinum coils in MMP-9 -knockout and wild-type mice.

BACKGROUND AND PURPOSE: Stents are increasingly used for coiling of difficult aneurysms, to reduce the risk of recurrences, or to modify blood flow. Currently available bifurcation aneurysm models are ill-suited to assess stent performance before clinical use. We designed a new wide-neck canine T-type bifurcation aneurysm model. Its potential value as a training tool as well as in the evaluation of new techniques or embolic agents was assessed. Our first task was to verify that recurrences occurred after satisfactory coiling. A second aim of this preliminary work was to assess if the new model could recreate the technical challenges involved in bifurcation aneurysms.

We present a canine lingual artery bifurcation aneurysm and assess its value for training in endovascular techniques and testing new embolic agents. The experimental aneurysm described herein mirrors human bifurcation aneurysms, and with this model, we sought to reproduce endovascular technical difficulties. However, the lesions created in this canine model did not show angiographic or histologic evidence of aneurysmal recurrence. We conclude that this model may be useful for training in endovascular techniques, but because of the lack of sufficient aneurysmal recurrence, it is not suitable for evaluating new embolic agents.

BACKGROUND AND PURPOSE: Endovascular treatment of wide neck aneurysms often results in incomplete occlusion or aneurysm recurrence. The two goals of the present study were to compare results of coil embolization with or without the assistance of an aneurysm neck bridge device (ANBD) and to explore the use of this instrument to control cyanoacrylate embolization.

Objective: Type 2 diabetes mellitus results in a procoagulant and thrombogenic state that could predispose diabetic individuals to develop venous thrombosis. We sought to determine whether diet-induced type 2 diabetes mellitus affects deep venous thrombosis (DVT) resolution in a murine model. Methods: C57Bl/6 mice were fed a low-fat or a high-fat diet (n ‫؍‬ 10) for 10 weeks, after which DVT was created in the inferior vena cava (IVC) by a combination of low flow and endothelial damage. The IVC and thrombus were harvested at 1 and 2 weeks. Thrombus resolution and neovascularization were investigated through transfemoral angiography (n ‫؍‬ 10), thrombus size (n ‫؍‬ 4) and weight (n ‫؍‬ 10), and nitric oxide synthase 3 immunoquantification (n ‫؍‬ 4). Macrophage content was assessed by CD68 immunoreactivity (n ‫؍‬ 4). The fibrinolytic system (urokinase plasminogen activator [uPA] and plasminogen activator inhibitor-1 [PAI-1]) was analyzed by Western immunoblotting (n ‫؍‬ 6) and immunohistochemistry (n ‫؍‬ 4). Total collagen was stained by Sirius red. Matrix metalloproteinases (MMP)-2 and MMP-9 activities were evaluated by zymography and their expressions by Western immunoblotting (n ‫؍‬ 6) and immunohistochemistry (n ‫؍‬ 4). Results: Diabetic mice had significantly larger and heavier thrombi at 1 and 2 weeks (P < .05), threefold less neovascularization (P < .05), and 35-fold increase in macrophage content (P < .01), than control mice 2 weeks after surgery. IVC recanalization was documented in 90% of 2-week control mice and in 10% of 2-week diabetic mice (P < .01). Increased vein wall collagen and less uPA and more PAI-1 expressions with a decreased uPA/PAI-1 ratio (31%, P < .01) were documented at 2 weeks in diabetic mice. MMP-2 and MMP-9 activities and expressions were significantly increased in diabetic mice at 1 and 2 weeks (P < .05) compared with control mice.

BACKGROUND AND PURPOSE: Endovascular treatment of aneurysms may result in complete or incomplete occlusions or may be followed by recurrences. The goal of the present study was to better define pathologic features associated with so-called healing or recurrences after coiling and to propose an alternative concept to the currently accepted view.

Background: Stents are increasingly used in the endovascular treatment of intracranial aneurysms. We studied the effects of stenting and endothelial denudation on aneurysm and branch vessel occlusion. Methods: Bilateral lingual bifurcation venous pouch aneurysms were created in eight dogs, surgically scraping the aneurysmal endothelial lining on one side. Both arteries were immediately stented using balloon-expandable stents. In four other dogs, a wide-neck carotid bifurcation aneurysm was created, with the vein pouch denuded or not (n ‫؍‬ 2 each), followed by immediate stenting. Results were compared using angiography and pathology at 10 days (n ‫؍‬ 2), 10 (n ‫؍‬ 8), and 20 weeks (n ‫؍‬ 2). Branch occlusion between initial and final angiograms was recorded. Pathological evaluation of aneurysms was studied, with attention to neointima formation at the aneurysm ostium and around branch vessel origins. Results: All stented and denuded lingual aneurysms were obliterated compared with two of eight lingual aneurysms that were stented alone (P ‫؍‬ .007). None of the carotid bifurcation aneurysms became obliterated (0/4), but denuded aneurysms showed partial thrombosis (2/2). Of 68 total stent-covered branches, 5 (7%) were occluded and 17 (27%) had altered angiographic flow.

The ultimate methodology necessary to adopt a treatment as generally beneficial is the randomized controlled trial, a method designed by and for clinicians to maximize the care of their patients in the presence of uncertainty. Some selection is however necessary to limit trials to more promising and less risky endeavors. Experimental models are the privileged answer to the problem of finding scientific evidence while refraining from harming patients in the course of this pursuit. They allow a step by step assessment, from simple but artificial settings to more complex and realistic animal models. But the use of animal models can only be justified if the community can be convinced that alternatives have been considered but are invalid, when the project is scientifically sound and methodologically irreproachable.

BACKGROUND AND PURPOSE: Endovascular treatment of aneurysms may result in complete or incomplete occlusions or may be followed by recurrences. The goal of the present study was to better define pathologic features associated with so-called healing or recurrences after coiling and to propose an alternative concept to the currently accepted view.

Urban malaria is considered a major public health problem in Africa. The malaria vector is well adapted in urban settings and autochthonous malaria has increased. Antimalarial treatments prescribed presumptively or after rapid diagnostic tests are also highly used in urban settings. Furthermore, health care strategies for urban malaria must comply with heterogeneous neighbourhood ecosystems where health-related risks and opportunities are spatially varied. This article aims to assess the capacity of the urban living environment to mitigate or increase individual or household vulnerabilities that influence the use of health services. The data are drawn from a survey on urban malaria conducted between 2008 and 2009. The study sample was selected using a two-stage randomized sampling. The questionnaire survey covered 2952 households that reported a case of fever episode in children below 10 years during the month before the survey. Self-medication is a widespread practice for children,...

Senegal opted for an antimalarial drug policy (artemisinin-based combination therapy) of partial and then full exemption from health care costs for the whole population respectively in 2008 and 2010. Has this policy reduced access inequalities in children’s health care between rich and poor households? Data were collected in Dakar between 2008 and 2009 as part of a research program on urban malaria. A survey was conducted among the population of the Dakar metropolitan area. The sample was based on a two-stage sampling. The three questionnaires used for the survey were based on validated data collection tools. Indicators were built to characterize individuals, households and neighborhoods. Bivariate analysis (chi2 test) revealed social gradients within the Dakar agglomeration and characterized health care behaviors of the poorest and richest households. Data have therefore been adjusted by a double zero-inflated Poisson model. Results show that the policy of subsidizing antimalarial ...

BACKGROUND In resource-poor settings, lack of awareness and low demand for services constitute important barriers to expanding the coverage of effective interventions. In India, childhood immunization is a priority health strategy with suboptimal uptake. OBJECTIVE To assess study feasibility and key implementation outcomes for the Tika Vaani model, a new approach to educate and empower beneficiaries to improve immunization and child health. METHODS A cluster-randomized pilot trial with a 1:1 allocation ratio was conducted in rural Uttar Pradesh, India, from January to September 2018. Villages were randomly assigned to either the intervention or control group. In each participating village, surveyors conducted a complete enumeration to identify eligible households and requested participation before randomization. Interventions were designed through formative research using a social marketing approach and delivered over 3 months using strategies adapted to disadvantaged populations: (...