In Vivo Analysis Of Angiotensin II-Induced Hypertension And Vascular Disease In Rats

Murine models of abdominal aortic aneurysms (AAA) are commonly used to study the pathogenesis of this disease. Rats are often used in laboratory studies because of their size and because they are more physiologically similar to humans than mice are. In this study, we subcutaneously implanted 9-week-old apolipoprotein E-deficient (apoE KO) rats with angiotensin II-filled pumps to study the effects of this vasoconstricting hormone on aneurysm development. Deletion of the apoE gene in mice causes excess lipid accumulation in the blood vessels, thereby increasing the likelihood of atherosclerotic lesions in the aorta. However, atherosclerotic plaque buildup was not evident when the rats consumed either normal chow or high fat diets, and no dissecting aneurysms were identified via ultrasound. We observed an average of 32.5 +/- 28.8 mmHg increase in systolic blood pressures as early as 4 days post-pump implantation and an increase of 54.2 +/- 25.9 mmHg from baseline 6 weeks after angiotensin II infusion began. This study shows that apoE KO rats can be valuable models for the physiological development of hypertension but not for dissecting suprarenal aneurysms. Future studies will focus on studying the effects of angiotensin II on the hearts of these genetically modified animals

Changes in Vessel Properties During Early Progression of Murine Abdominal Aortic Aneurysms from In Vivo Ultrasound

Abdominal aortic aneurysms (AAA) are a common and frequently fatal disease characterized by the weakening and dilation of the aorta. The larger the aneurysm, the higher the chances are of rupturing and life-threatening hemorrhage. The aim of this study is to apply the angiotensin II (AngII) model of AAAs in male apolipoprotein-E-deficient mice (apoE-/- C57Bl/6J), in order to analyze, quantify, and understand the pathologies and characteristics associated with early AAA development. To date, many studies focusing on the evaluation of AAA characteristics have been performed ex vivo. Therefore, we focused on in vivo assessment, through the use of high frequency ultrasound technology, to measure parameters such as aortic diameter, volume, circumferential cyclic strain, blood flow velocity, and thrombus volume. Data analysis from this 7-day study suggests an increase in aortic diameter and volume, a decrease in aortic blood flow velocity and strain, and large variations in volumes of the thrombotic volume within the aneurysm’s false lumen. Our analysis of these AAA features has shown that there are a variety of patterns, which may provide insight into further understanding AAA pathology in this model. Future work will focus on comparing the relationship between the features during early AAA formation

Characterization of Left-Ventricular Thrombus Formation Using High Frequency Ultrasound

Heart failure is a leading cause of death in the United States, and cardiac thrombus, a common morbidity associated with heart failure, significantly increases a patient’s risk of embolic events. The objective of this project is to characterize left-ventricular (LV) thrombus development using high frequency ultrasound imaging in a murine model. C57BL/6J wild-type mice (n=6) were injected intraperitoneally with iron dextran five times a week for six weeks to increase oxidative stress in the heart. Granulocyte-colony stimulating factor (G-CSF) was subcutaneously injected daily during the second week to initiate stem cell migration and stimulate endothelial cell activation, thus increasing the hypercoagulability state of the blood. A high-frequency, small animal ultrasound system (Vevo2100, VisualSonics FUJIFILM Inc.) and a 40 MHz central frequency transducer were used to track LV thrombus progression and evaluate LV function weekly. Four out of six mice developed thrombus, but no significant differences in LV performance were observed when compared to mice that did not form a thrombus. Further investigation is necessary to study the role of attenuated heart function on thrombus formation. Future work will incorporate a murine model of myocardial infarction to investigate if a severely compromised heart increases the risk of or accelerates LV thrombus formation. This study will aid in identifying patients who are predisposed to thrombus formation following a heart attack, leading to more effective prevention and treatment methods

Integrated pest management in vegetable production: a guide for extension workers in West Africa

Indigenous and exotic vegetables are central to most nutrition, food security and poverty reduction programmes around the world. However, in most of West Africa, the economic opportunities offered by vegetables are often undermined by production and trade constraints (i.e. pest damage, inappropriate pesticide usage, absence of environmental safeguard policies and/or stringent food safety standards). Extension workers and, in places, farmers groups and local community organizations, are working towards helping farmers to increase their yields in sustainable ways that create wealth and reduce the risks to productivity. All too often, extension workers do not know the cause of common pest problems in the crops they work with. Pest problems usually arise when the biological, ecological and sociological processes which underpin agriculture are disrupted. This guide helps to fill that information gap. It is one of many responses by the International Institute of Tropical Agriculture (IITA) which enables such workers to develop and use technologies. It focuses on accurate identification and better understanding of biodiversity in the development and application of Integrated Pest Management (IPM) options against vegetable pests. IPM is a knowledge-intensive approach to enhance profitability of agricultural systems, while minimizing threats to human health and the environment. The technical knowledge and skills in this guide can be used to look for, develop and apply effective vegetable IPM options. The IPM options outlined here are in harmony with the environment, sustainable, simple to apply, and cheap to maintain. The guide addresses IITA’s strategic aim of increasing the quality and usefulness of IPM research in support of reducing food security and poverty. It draws heavily on IITA’s experiences in Africa, with a particular emphasis on vegetable agroecosystems in Benin. Given the substantial economic costs of pest infestations in vegetable agroecosystems, the use of this guide in Africa is expected to improve incomes and overall agricultural productivity in the long-term. Peter Hartmann Director General International Institute of Tropical Agriculture March 2010 ForewordThis guide has been produced by the International Institute of Tropical Agriculture (IITA) and Institut National des Recherches Agricoles du Bénin (INRAB), Cotonou, Benin, with support from the CGIAR Systemwide Program on Integrated Pest Management (SP-IPM), to improve the quality and usefulness of pest management research. This publication was part funded by the ACP-EU Technical Centre for Agricultural and Rural Cooperation (CTA)

Three Dimensional Quantification of Angiotensin II-Induced Murine Abdominal Aortic Aneurysms Using High Frequency Ultrasound

Abdominal aortic aneurysms (AAAs), a localized dilation of the vessel wall of 50% or more above normal, claims approximately 14,000 U.S. lives yearly due to aortic rupture. This commonly asymptomatic disease can only be treated by endovascular stent grafts or invasive surgery, usually after the AAA diameter reaches 5 cm. Because these treatment methods carry serious risk, stem cell therapy is being explored in order to provide a low risk option for managing smaller AAAs. To determine if stem cell therapy, once administered, could stabilize or reduce AAA growth, baseline 3D ultrasound measurements in a control group were first needed. High frequency ultrasound was used on apolipoprotein E-deficient (apoE-/-) mice given angiotensin II (AngII) from subcutaneously implanted osmotic mini pumps. This mouse model developed dissecting AAAs, containing a false and true lumen, which were clearly visualized and quantified using 3D ultrasound imaging. With this ultrasound technique, we found that aneurysm diameter, total volume, and false lumen volume all increased steadily over a period of 28 days once AAAs formed. These data suggest our noninvasive, 3D ultrasound technique can be used to monitor the progression of aneurysms that may be delayed once stem cell therapy is administered

Economic evaluation of a clinical protocol for diagnosing emergency patients with suspected pulmonary embolism

BACKGROUND: The objective of this paper is to estimate the amount of cost-savings to the Australian health care system from implementing an evidence-based clinical protocol for diagnosing emergency patients with suspected pulmonary embolism (PE) at the Emergency department of a Victorian public hospital with 50,000 presentations in 2001–2002. METHODS: A cost-minimisation study used the data collected in a controlled clinical trial of a clinical protocol for diagnosing patients with suspected PE. Thenumber and type of diagnostic tests in a historic cohort of 185 randomly selected patients, who presented to the emergency department with suspectedPE during an eight month period prior to the clinical trial (January 2002 -August 2002) were compared with the number and type of diagnostic tests in745 patients, who presented to the emergency department with suspected PE from November 2002 to August 2003. Current Medicare fees per test were usedas unit costs to calculate the mean aggregated cost of diagnostic investigation per patient in both study groups. A t-test was used to estimate the statistical significance of the difference in the cost of resources used for diagnosing PE in the control and in the intervention group. RESULTS: The trial demonstrated that diagnosing PE using an evidence-based clinical protocol was as effective as the existing clinical practice. The clinical protocol offers the advantage of reducing the use of diagnostic imaging, resulting in an average cost savings of at least $59.30 per patient. CONCLUSION: Extrapolating the observed cost-savings of$59.30 per patient to the wholeof Australia could potentially result in annual savings between $3.1 million to$3.7 million

Microstructural characterization of myocardial infarction with optical coherence tractography and two‐photon microscopy

Abstract Myocardial infarction leads to complex changes in the fiber architecture of the heart. Here, we present a novel optical approach to characterize these changes in intact hearts in three dimensions. Optical coherence tomography (OCT) was used to derive a depth‐resolved field of orientation on which tractography was performed. Tractography of healthy myocardium revealed a smooth linear transition in fiber inclination or helix angle from the epicardium to endocardium. Conversely, in infarcted hearts, no coherent microstructure could be identified in the infarct with OCT. Additional characterization of the infarct was performed by the measurement of light attenuation and with two‐photon microscopy. Myofibers were imaged using autofluorescence and collagen fibers using second harmonic generation. This revealed the presence of two distinct microstructural patterns in areas of the infarct with high light attenuation. In the presence of residual myofibers, the surrounding collagen fibers were aligned in a coherent manner parallel to the myofibers. In the absence of residual myofibers, the collagen fibers were randomly oriented and lacked any microstructural coherence. The presence of residual myofibers thus exerts a profound effect on the microstructural properties of the infarct scar and consequently the risk of aneurysm formation and arrhythmias. Catheter‐based approaches to segment and image myocardial microstructure in humans are feasible and could play a valuable role in guiding the development of strategies to improve infarct healing

Fertility and gonadal function in female survivors after treatment of early unfavorable Hodgkin lymphoma (HL) within the German Hodgkin Study Group HD14 trial

Background In the HD14 trial, 2× BEACOPPescalated+2× ABVD (2+2) has improved the primary outcome. Compared with 4× ABVD, this benefit might be compromised by more infertility in women. Therefore, we analyzed gonadal function and fertility. Patients and methods Women ≤45 years in ongoing remission at least 1 year after therapy were included. Hormone parameters, menopausal symptoms, measures to preserve fertility, menstrual cycle, pregnancies, and offspring were evaluated. Results Three hundred and thirty one of 579 women addressed participated (57.2%) and 263 per-protocol treated patients qualified (A=ABVD: 137, B=2+2: 126, mean time after therapy 42 and 43 months, respectively). Regular menstrual cycle after treatment (A: 87%, B: 83%) and time to recovery (≤12 months) were not different. Follicle-stimulating hormone and anti-Muellerian hormone were significantly better in arm A. However, pregnancies after therapy favored arm B (A: 15%, B: 26%, P=0.043) and motherhood rates were equivalent to the German normal population. Multivariate analysis revealed prophylactic use of gonadotropin-releasing hormone (GnRH) analogues as highly significant prognostic factor for preservation of fertility (odds ratio=12.87, P=0.001). Severe menopausal symptoms were frequent in women ≥30 years (A: 21%, B: 25%). Conclusions Hormonal levels after 2+2 indicate a reduced ovarian reserve. However, 2+2 in combination with GnRH analogues does not compromise fertility within the evaluated observation tim

Gestion intégrée des nuisibles en production maraîchère : Guide pour les agents de vulgarisation en Afrique de l'Ouest

Les parasites se manifestent généralement en cas de bouleversement des processus biologiques, écologiques et sociologiques qui sous-tendent l'agriculture. En plus d'apporter des informations sur la gestion durable des menaces biotiques portées à une production végétale saine, ce guide suggère également des manières d'enseigner et de diffuser des pratiques de lutte antiparasitaire intégrée auprès d'un public plus large. Exceptionnellement bien illustré par des illustrations, tableaux et photos, cet ouvrage se promet d'être une référence précieuse pour les professionnels sur le terrain, les agents de vulgarisation, les techniciens, les étudiants et les scientifiques

Nonlinear Optical Microscopy of Murine Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is a cardiovascular disease characterized by dilation and weakening of the vessel wall. AAA rupture is responsible for approximately 14,000 deaths annually in the United States [1]. Nonlinear optical (NLO) microscopy presents new possibilities for analyzing AAA tissue samples from murine models. Common NLO techniques are two-photon excitation fluorescence (TPEF), which detects the intrinsic autofluorescent properties of elastin, and second-harmonic generation (SHG), which is specific for collagen fibrils. Elastin and collagen, two major extracellular matrix components, help the aortic wall withstand internal pressure. Murine AAAs were created through 1) subcutaneous continuous systemic infusion of angiotensin II (AngII) in hyperlipidemic apolipoprotein E-deficient mice and 2) by intraluminal infusion of elastase (low 0.5 U/ml and high 25 U/ml concentrations) into the infrarenal aorta of rats [2]. We imaged aneurysmal and control tissue using TPEF and SHG and compared the resulting images to sections stained with standard elastin and collagen markers. TPEF images revealed disorganized elastin sheets and SHG images indicated collagen turnover after aneurysm formation. We quantified the relative degree of elastin degradation and collagen content in the aortic media within a user-defined area on sections stained with Verhoeff-van Gieson (VVG) or Masson’s trichrome (MTC), as well as on TPEF and SHG images. Our analysis with VVG-stained sections shows that elastin content in AAA tissue is significantly decreased by 64% in AngII models (P=0.02), by 34% in low concentration elastase models (P=0.07), and by 99% in high concentration elastase models (P=0.03), relative to control aortic tissue