Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

The Diabetic Vasculature: Physiological Mechanisms Of Dysfunction And Influence Of Aerobic Exercise Training In Animal Models

Diabetes mellitus (DM) is associated with a number of complications of which chronic vascular complications are undoubtedly the most complex and significant consequence. With a significant impact on health care, 50-80% of people with diabetes die of cardiovascular disease (including coronary artery disease, stroke, peripheral vascular disease and other vascular disease), making it the major cause of morbidity and mortality in diabetic patients. A healthy lifestyle is essential in the management of DM, especially the inclusion of aerobic exercise, which has been shown effective in reducing the deleterious effects in vasculature. Interest in exercise studies has increased significantly with promising results that demonstrate a future for investigation. Considering the importance of this emerging field, the aim of this mini-review is to summarize and integrate animal studies investigating physiological mechanisms of vascular dysfunction and remodeling in type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) and how these are influenced by chronic aerobic exercise training. © 2014 Elsevier Inc.10211913SDG16840035; AHA; American Heart AssociationAbebe, W., Macleod, K.M., Enhanced arterial contractility to noradrenaline in diabetic rats is associated with increased phosphoinositide metabolism (1991) Can J Physiol Pharmacol, 69, pp. 355-361Abebe, W., Macleod, K.M., Influence of diabetes on noraepinephrine-induced inositol 1,4,5-trisphosphate levels in rat aorta (1991) Life Sci, 49, pp. 85-PL90Agrawal, D.K., McNeill, J.H., Vascular responses to agonists in rat mesenteric artery from diabetic rats (1987) Can J Physiol Pharmacol, 65, pp. 1484-1490Standards of medical care for patients with diabetes mellitus (1997) Diabetes Care, 20, pp. 3-S13. , American Diabetes AssociationDiagnosis and classification of diabetes mellitus (2005) Diabetes Care, 28, pp. 37-S42. , American Diabetes AssociationArozal, W., Watanabe, K., Veeraveedu, P.T., Ma, M., Thandavarayan, R.A., Suzuki, K., Effects of angiotensin receptor bloker on oxidative stress and cardio-renal function in streptozotocin-induced diabetic rats (2009) Biol Pharm Bull, 32, pp. 1411-1416Avogaro, A., De Kreutzenberg, S.V., Fadini, G., Endothelial dysfunction: Causes and consequences in patients with diabetes mellitus (2008) Diabetes Res Clin Pract, 15, pp. 94-S101. , 10.1016/j.diabres.2008.09.021Baluchnejadmojarad, T., Roghani, M., Chronic administration of genistein improves aortic reactivity of streptozotocin-diabetic rats: Mode of action (2008) Vascul Pharmacol, 49, pp. 1-5. , 10.1016/j.vph.2008.03.002Bender, S.B., Klabunde, R.E., Altered role of smooth muscle endothelin receptors in coronary endothelin-1 and α1-adrenoceptor-mediated vasoconstriction in type 2 diabetes (2007) Am J Physiol Heart Circ Physiol, 293, pp. 2281-H2288. , 10.1152/ajpheart.00566.2007Bianchi, M.L.P., Antunes, L.M.G., Free radical and the main dietary antioxidants (1999) Rev Nutr, 12, pp. 123-130Boor, P., Celec, P., Behuliak, M., Grancic, P., Kebis, A., Kukan, M., Regular moderate exercise reduces advanced glycation and ameliorates early diabetic nephropathy in obese Zucher rats (2009) Metabolism, 58, pp. 1669-1677. , 10.1016/j.metabol.2009.05.025Booth, F.W., Laye, M.J., Spangenburg, E., (2010) Gold Standards for Scientists Who Are Conducting Animal-based Exercise Studies, 108, pp. 219-221. , 10.1152/japplphysiol.00125.2009Brondum, E., Kold-Petersen, H., Nilsson, H., Flycbjerg, A., Aalkjaer, C., Increased contractility to noradrenaline and normal endothelial function in mesenteric small arteries from the Goto-kakizaki rat model of type 2 diabetes (2008) J Physiol Sci, 58, pp. 333-339. , 10.2170/physiolsci.RP010108Bruno, R.M., Ghiadoni, L., Vascular smooth muscle function: Defining the diabetic vascular phenotype (2013) Diabetologia, 56, pp. 2107-2109Bucala, R., Tracey, K.J., Cerami, A., Advanced glycosylation products quench nitric oxide and mediate defective endothelium-dependent vasodilatation in experimental diabetes (1991) J Clin Invest, 87, pp. 432-438Bunker, A.K., Arce-Esquivel, A.A., Rector, R.S., Booth, F.W., Ibdah, J.A., Laughlin, M.H., Physical activity maintains aortic endothelium-dependent relaxation in the obese type 2 diabetic OLETF rat (2010) Am J Physiol Heart Circ Physiol, 298, pp. 889-H901. , 10.1152/ajpheart.01252.2009Cade, W.T., Diabetes-related microvascular and macrovascular diseases in the physical therapy setting (2008) Phys Ther, 88 (11), pp. 1322-1335Carr, C.L., Qi, Y., Davidson, B., Chadderdon, S., Jayaweera, A.R., Belcik, J.T., Dysregulated selectin expression and monocyte recruitment during ischemia-related vascular remodeling in diabetes mellitus (2011) Arterioscler Thromb Vasc Biol, 31, pp. 2526-2533. , 10.1161/ATVBAHA.111.230177Caspersen, C.J., Powell, K.E., Christenson, G.M., Physical activity, exercise and physical fitness: Definitions and distinctions for health-related research (1985) Public Health Rep, 100, pp. 126-131Celik, T., Iyisoy, A., Yuksel, U.C., Pediatric metabolic syndrome: A growing threat (2010) Int J Cardiol, 23, pp. 302-303. , 10.1016/j.ijcard.2008.11.143Chakraphan, D., Sridulyakul, P., Thipakorn, B., Bunnag, S., Hyxley, V.H., Patumraj, S., Attenuation of endothelial dysfunction by exercise training in STZ-induced diabetic rats (2005) Clin Hemorheol Microcirc, 32, pp. 217-226Chang, S.P., Chen, Y.H., Chang, W.C., Liu, I.M., Cheng, J.T., Increase of adiponectin receptor gene expression by physical exercise in soleus muscle of obese Zucker rats (2006) Eur J Appl Physiol, 97, pp. 189-195Chen, K.D., Li, Y.S., Kim, M., Li, S., Yuan, S., Chien, S., Mechanotransduction in response to shear stress. 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Primary role of angiotensin converting enzyme 2 in cardiac production of angiotensin-(1-7) in transgenic Ren-2 hypertensive rats

Angiotensin-converting enzyme 2 (ACE2) converts angiotensin II (Ang II) to angiotensin-(1-7) [Ang-(1-7)] and this enzyme may serve as a key regulatory juncture in various tissues. Although the heart expresses ACE2, the extent that the enzyme participates in the cardiac processing of Ang II and Ang-(1-7) is equivocal. Therefore, we utilized the Langendorff preparation to characterize the ACE2 pathway in isolated hearts from male normotensive Sprague-Dawley [Tg((-))] and hypertensive [mRen2]27 [Tg((+))] rats. During a 60-minute recirculation period with 10 nM Ang II, the presence of Ang-(1-7) was assessed in the cardiac effluent. Ang-(1-7) generation from Ang II was similar in both the normal and hypertensive hearts (Tg((-)): 510 +/- 55 pM, n=20 versus Tg((+)): 497 +/- 63 pM, n=14) with peak levels occurring at 30 minutes after administration of the peptide. ACE2 inhibition (MLN-4760, 1microM) significantly reduced Ang-(1-7) production by 83% (57 +/- 19 pM, P < 0.01, n=7) in the Tg((+)) rats, whereas the inhibitor had no significant effect in the Tg((-)) rats (285 +/- 53 pM, P > 0.05, n=10). ACE2 activity was found in the effluent of perfused Tg((-)) and Tg((+)) hearts and it was highly associated with ACE2 protein expression (r =0.78). This study is the first demonstration for a direct role of ACE2 in the metabolism of cardiac Ang II in the hypertrophic heart of hypertensive rats. We conclude that predominant expression of cardiac ACE2 activity in the Tg((+)) may be a compensatory response to the extensive cardiac remodeling in this strain. Key words: angiotensin II, hypertension, isolated heart