Evaluation of Renal Pathophysiological Processes Induced by an Iodinated Contrast Agent in a Diabetic Rabbit Model Using Intravoxel Incoherent Motion and Blood Oxygenation Level-Dependent Magnetic Resonance Imaging

OBJECTIVE: To examine the potential of intravoxel incoherent motion (IVIM) and blood oxygen level-dependent (BOLD) magnetic resonance imaging for detecting renal changes after iodinated contrast-induced acute kidney injury (CI-AKI) development in a diabetic rabbit model. MATERIALS AND METHODS: Sixty-two rabbits were randomized into 2 groups: diabetic rabbits with the contrast agent (DCA) and healthy rabbits with the contrast agent (NCA). In each group, 6 rabbits underwent IVIM and BOLD imaging at 1 hour, 1 day, 2 days, 3 days, and 4 days after an iohexol injection while 5 rabbits were selected to undergo blood and histological examinations at these specific time points. Iohexol was administrated at a dose of 2.5 g I/kg of body weight. Further, the apparent transverse relaxation rate (R2*), average pure molecular diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) were calculated. RESULTS: The D and f values of the renal cortex (CO) and outer medulla (OM) were significantly decreased compared to baseline values in the 2 groups 1 day after the iohexol injection (p < 0.05). A marked reduction in the D* values for both the CO and OM was also observed after 1 hour in each group (p < 0.05). In the OM, a persistent elevation of the R2* was detected for 4 days in the DCA group (p < 0.05). Histopathological changes were prominent, and the pathological features of CI-AKI aggravated in the DCA group until day 4. The D, f, and R2* values significantly correlated with the histological damage scores, hypoxia-inducible transcription factor-1α expression scores, and serum creatinine levels. CONCLUSION: A combination of IVIM and BOLD imaging may serve as a noninvasive method for detecting and monitoring CI-AKI in the early stages in the diabetic kidney.

Vascular dysfunction in obesity: beneficial effects of aerobic exercise training in animal models

Abstract Cardiovascular disease (CVD) is the leading cause of mortality in the world and several risk factors for developing CVD have been pointed out, including obesity and physical inactivity. Endothelial dysfunction as a consequence of metabolic and inflammatory disorders plays an important role in the onset of vascular complications in obesity. In addition, it is well established that aerobic exercises promote beneficial effects on CVD by increasing nitric oxide (NO) production or its bioavailability in human and experimental models. The interest in exercise studies increased significantly, with promising results. Considering the importance of this field, the purpose of this mini-review is to summarize the animal studies that investigated the physiological mechanisms of vascular dysfunction in obesity and how aerobic exercise training influenced these alterations.(AU)

Vascular dysfunction as a target for adjuvant therapy in cerebral malaria

Cerebral malaria (CM) is a life-threatening complication of Plasmodium falciparum malaria that continues to be a major global health problem. Brain vascular dysfunction is a main factor underlying the pathogenesis of CM and can be a target for the development of adjuvant therapies for the disease. Vascular occlusion by parasitised red blood cells and vasoconstriction/vascular dysfunction results in impaired cerebral blood flow, ischaemia, hypoxia, acidosis and death. In this review, we discuss the mechanisms of vascular dysfunction in CM and the roles of low nitric oxide bioavailability, high levels of endothelin-1 and dysfunction of the angiopoietin-Tie2 axis. We also discuss the usefulness and relevance of the murine experimental model of CM by Plasmodium berghei ANKA to identify mechanisms of disease and to screen potential therapeutic interventions.

Cardiovascular protection by curcumin: Molecular aspects.

Curcumin is the active component in turmeric — a spice that has been extensively used as a culinary agent and a home remedy to prevent and treat many diseases in India and other countries for hundreds of years. However, systematic studies to understand the molecular basis of disease preventing or therapeutic properties of curcumin began to appear in the scientific literature only during the last 40 years. As a result of these studies, substantial evidence has accumulated to suggest that curcumin can affect signaling pathways linked to cellular growth, proliferation, survival, inflammation and transcription. In addition, curcumin has also been shown to exert anti-atherosclerotic, anti-cancer, anti-diabetic, anti-inflammatory and anti-oxidative properties in animal models of various diseases and in human subjects. In this article, we highlight the cardiovascular protective role of curcumin with an emphasis on the molecular basis of this effect.

Effects of life style intervention on obesity-related vascular dysfunction in children / 中华流行病学杂志

Objective To evaluate the reversibility of obesity-related arterial dysfunction and thickening carotid intima-media through dietary and/or exercise intervention programs.Methods Seventyeight 9 to 12 year-old overweight children,were randomly assigned to group A:only dietary modification,group B:diet plus a supervised structured exercise program for 6 weeks(SE)and subsequently for 1 year (CE).The prospectively defined primary end points were assessed through ultrasound-derived arterial endothelial function(endothelium-dependent dilation)of the brachial artery and intima-media thickness of common carotid artery.Results At 6 weeks,both interventions were associated with improved arterial endothelial function[group A:(6.36±0.81)% vs.(5.32±0.84)%,P＜0.01;group B:(7.46±0.91)% vs.(5.20±0.87)%,P＜0.01 ].A conbination of diet and exercise were associated with a significantly greater improvement in endothelial function than on diet alone(P＜0.01).At 1 year,there appeared significantly Less thickening of the carotid wall in group CE[(0.57±0.05)mm vs.(0.59±0.07)mm,P＜0.001].Compared with children in group SE[(6.38±1.04)% vs.(5.22±0.96)%,P＜0.05],vascular function appeared significantly better in group CE[(8.29±0.78)% vs.(5.38±0.65)%,P＜0.001].Conclusion Obesity-related vascular dysfunction in young children was partially reversible with diet alone but more obvious when combined with exercise training for 6 weeks.Sustained improvements at 1 year was seen in those who persisted in diet program plus regular exercise.