1 BETA-BLOCKING DRUG USE IN COCAINE ABUSERS: IS IT SAFE AND EFFECTIVE THERAPY IN HOSPITALIZED PATIENTS? GD. Everett, N. Uddin, A. Java, A. Klotchko, A. Velazquez, S. Singapuri, A. Prevost, R. Rostorfer, E. Benzaquen, K. Patel, V. Patel, P. Fotso, L. Ramos Florida Hospital Medical Center, Orlando, FL; University of Central Florida, Orlando, FL and Orlando Health, Orlando, FL. Purpose of Study: Case reports have suggested that beta-blockers may unpredictably exacerbate hypertension and tachycardia in concurrent cocaine abusers. Physicians avoid beta-blockers in these patients despite the chest pain and hypertension that cocaine may cause. This study was designed to assess the physiological effect of beta-blockers given to cocaine abusers during emergency room and hospital stays when their symptoms warrented beta-blockers but before their use of cocaine was discovered. Methods Used: A cohort consisting of every patient admitted to a large, urban hospital during a single calendar year, whose urine contained cocaine metabolites, was created. Subjects were included if they had blood pressure and heart rate measurements recorded before and after beta-blockers or other medications were given. 114 subjects met the criteria. Multivariate regression analysis was used to assess the independent effect of beta-blockers on the blood pressure and heart rate. The regression analysis controlled for the effect of each vasoactive medication given to the subjects. Summary of Results: The subjects were 33% female, 64% black, 27% white and 9% other race. The median age was 43(23Y74). Chest pain (30%) was the most common admission complaint. 5% of subjects had a troponin level of more than 1.0. 14% and 4% of subjects had creatinine values that exceeded 3.0 and 9.0 respectively. The table displays the results of the main analysis: unadjusted and multivariate adjusted effects of beta-blockers on systolic BP, diastolic BP, and heart rate. Conclusions: There was no evidence of a deleterious or paradoxical effect of beta blockers when administered to patients documented to be using cocaine.

Aims/hypothesis Elevated anti-angiogenic factors such as soluble fms-like tyrosine kinase 1 (sFlt1), a soluble form of vascular endothelial growth factor receptor, and endoglin, a co-receptor for TGF beta 1, confer high risk of pre-eclampsia in healthy pregnant women. In this multicentre prospective study, we determined levels of these and related factors in pregnant women with type 1 diabetes, a condition associated with a fourfold increase in pre-eclampsia.Methods Maternal serum sFlt1, endoglin, placental growth factor (PlGF) and pigment epithelial-derived factor were measured in 151 type 1 diabetic and 24 healthy non-diabetic women at each trimester and at term.Results Approximately 22% of the diabetic women developed pre-eclampsia, primarily after their third trimester visit. In women with pre-eclampsia (diabetic pre-eclampsia, n=26) vs those without hypertensive complications (diabetic normotensive, n=95), significant changes in angiogenic factors were observed, predominantly in the early third trimester and prior to clinical manifestation of pre-eclampsia. Serum sFlt1 levels were increased approximately twofold in type 1 diabetic pre-eclampsia vs type 1 diabetic normotensive women at the third trimester visit (p<0.05) and the normal rise of PlGF during pregnancy was blunted (p<0.05). Among type 1 diabetic women, third trimester sFlt1 and PlGF were inversely related (r(2)=42%, p<0.0001). Endoglin levels were increased significantly in the diabetic group as a whole vs the non-diabetic group (p<0.0001).Conclusions/interpretation Higher sFlt1 levels, a blunted PlGF rise and an elevated sFlt1/PlGF ratio are predictive of pre-eclampsia in pregnant women with type 1 diabetes. Elevated endoglin levels in women with type 1 diabetes may confer a predisposition to pre-eclampsia and may contribute to the high incidence of pre-eclampsia in this patient group.

Tissue inhibitor of metalloproteinase (TIMP)-3 can inhibit neovascularization, a key event in the progression of diabetic retinopathy. We examined the influences of modified LDL on retinal pericyte expression of TIMP-3 compared with other TIMPs and matrix metalloproteinases (MMPs) since low-density lipoproteins (LDLs) modified by oxidation/glycation are implicated in diabetic vascular complications. Quiescent human retinal pericytes were exposed for 24 hours to native LDL (N-LDL), glycated LDL (G-LDL), and heavily oxidized-glycated LDL (HOG-LDL). TIMP and MMP expression were assessed at the level of mRNA (meta-analysis of microarray data, quantitative PCR) and protein (immunoblotting, ELISA). By microarray analysis, TIMP-1, -2, -3, and -4 and MMP-1, -2, -11, -14, and -25 expression was detected, but only TIMP-3 mRNA showed a differential response, being expressed at significantly lower levels in response to HOG-LDL versus N-LDL, and this was confirmed by quantitative PCR and immunoblotting of cell/matrix proteins. In contrast to TIMP-3 in cells, analyses of secreted TIMP-1, TIMP-2, MMP-1, and collagenase activity indicated no changes in their production in response to modified LDL. Combined N-LDL and HOG-LDL treatment restored TIMP-3 mRNA expression to levels comparable to N-LDL alone. We conclude that among the TIMPs and MMPs expressed in retinal pericytes, expression of TIMP-3 is uniquely regulated by HOG-LDL. Reduced TIMP-3 expression may be implicated in neovascularization in diabetic retinopathy.

Matrix metalloproteinases (MMPs) and their natural inhibitors, tissue inhibitor of metalloproteinases (TIMPs), regulate important biological processes including the homeostasis of the extracellular matrix, proteolysis of cell surface proteins, proteinase zymogen activation, angiogenesis and inflammation. Studies have shown that their balance is altered in retinal microvascular tissues in diabetes. Since LDLs modified by oxidation/glycation are implicated in the pathogenesis of diabetic vascular complications, we examined the effects of modified LDL on the gene expression and protein production of MMPs and TIMPs in retinal pericytes.

Tissue inhibitor of metalloproteinase (TIMP)-3 can inhibit neovascularization, a key event in the progression of diabetic retinopathy. We examined the influences of modified LDL on retinal pericyte expression of TIMP-3 compared with other TIMPs and matrix metalloproteinases (MMPs) since low-density lipoproteins (LDLs) modified by oxidation/glycation are implicated in diabetic vascular complications. Quiescent human retinal pericytes were exposed for 24 hours to native LDL (N-LDL), glycated LDL (G-LDL), and heavily oxidized-glycated LDL (HOG-LDL). TIMP and MMP expression were assessed at the level of mRNA (meta-analysis of microarray data, quantitative PCR) and protein (immunoblotting, ELISA). By microarray analysis, TIMP-1, -2, -3, and -4 and MMP-1, -2, -11, -14, and -25 expression was detected, but only TIMP-3 mRNA showed a differential response, being expressed at significantly lower levels in response to HOG-LDL versus N-LDL, and this was confirmed by quantitative PCR and immunoblotting of cell/matrix proteins. In contrast to TIMP-3 in cells, analyses of secreted TIMP-1, TIMP-2, MMP-1, and collagenase activity indicated no changes in their production in response to modified LDL. Combined N-LDL and HOG-LDL treatment restored TIMP-3 mRNA expression to levels comparable to N-LDL alone. We conclude that among the TIMPs and MMPs expressed in retinal pericytes, expression of TIMP-3 is uniquely regulated by HOG-LDL. Reduced TIMP-3 expression may be implicated in neovascularization in diabetic retinopathy.

PURPOSE:Modified (oxidized and/or glycated) low-density lipoproteins (LDLs) have been implicated in retinal pericyte loss, one of the major pathologic features of early-stage diabetic retinopathy. To delineate underlying molecular mechanisms, the present study was designed to explore the global effects of modified LDL on pericyte gene expression.METHODS:Quiescent human retinal pericytes were exposed to native LDL (N-LDL), glycated LDL (G-LDL), and heavily oxidized-glycated LDL (HOG-LDL) for 24 hours, and gene expression was evaluated by DNA microarray analysis. Several of the gene responses were checked, and in each case confirmed by reverse-transcription real-time PCR.RESULTS:HOG-LDL induced a gene expression pattern markedly distinct from that of N-LDL or G-LDL, whereas G-LDL elicited gene expression similar to that of N-LDL. A comparison of responses to HOG-LDL versus N-LDL revealed 60 genes with expression that varied by > or =1.7-fold. The HOG-LDL-responsive genes included members of functional pathways, such as fatty acid, eicosanoid, and cholesterol metabolism; fibrinolytic regulation; cell growth and proliferation; cell stress responses; the kinin system; and angiogenesis.CONCLUSIONS:HOG-LDL elicits gene expression in retinal pericytes that may contribute to pericyte loss and other retinal abnormalities in diabetic retinopathy. Observed proapoptotic and proangiogenic responses to HOG-LDL may be of particular importance in this regard. The genes identified through these studies provide potential therapeutic targets for the prevention and treatment of diabetic retinopathy.