Luci Maria SantAna Dusse

Diabetes mellitus: The linkage between oxidative stress, inflammation, hypercoagulability and vascular complications

BACKGROUND Vascular complications are the leading cause of morbidity and mortality among patients with type 1 and type 2 diabetes mellitus. These vascular abnormalities result of a chronic hyperglycemic state, which leads to an increase in oxidative stress and inflammatory responses. AIM This review addresses the relationships among endothelial dysfunction, hypercoagulability and inflammation and their biomarkers in the development of vascular complications in type 1 and type 2 diabetes. RESULTS Inflammation, endothelial dysfunction, and hypercoagulability are correlated to each other, playing an important role in the development of vascular complications in diabetic patients. Moreover, it has been observed that several endothelial, inflammatory and pro-coagulant biomarkers, such as VWF, IL-6, TNF-α, D-dimer and PAI-1, are increased in diabetic patients who have microvascular and macrovascular complications, including nephropathy or cardiovascular disease. CONCLUSION It is promising the clinical and laboratory use of endothelial, inflammatory and pro-coagulant biomarkers for predicting the risk of cardiovascular and renal complications in diabetic patients and for monitoring these patients.

Revisão sobre óxido nítrico

Nitric oxide (NO) is an inorganic and incolor free radical gas containing seven electrons from nitrogen and eigth from oxigen and one unpaired electron. Until midlle of 1980 decade, NO was considered as a member of an undesiderable and envirommental poluents family and as a potential carcinogen agents. At the moment, NO constitutes one of the most important mediators of intra and extra cellular processes. This radical is produced from the L-arginine envolving a reaction mediated by constitutive and inducible NO synthase. NO presents a dubious role, sometimes it brings benefits, sometimes it is harmful. It is envolved in the vascular relaxing and it protects the blood vessels. It constitutes an important cytotoxic mediator on immune activated cells capable of killing pathogenic agents and tumor cells. It also has a role as messager/modulator in a variety of essential biological processes. However, NO is a potentially toxic agent, whose toxicity could be particulary denoted in stress oxidative conditions, by the generation of O2 intermediates and antioxidant system deficiency. Laboratory measurement of NO is complex and the characterization of specific activators and inhibitors of the NO synthesis constitutes the new challenge for a better comprehension and treatment of a number of pathologies. NO studies have been one of the main target for pharmaceutical industries.

Pre-eclampsia: Relationship between coagulation, fibrinolysis and inflammation

Pre-eclampsia (PE) is a multi-system disorder of human pregnancy, characterised by hypertension and proteinuria. Although the pathogenesis of PE is not fully understood, predisposition to endothelial dysfunction is thought to play a crucial part. Despite intensive research there is no reliable test for screening purposes or to inform decision making towards effective treatment for PE. Understanding the link between PE, abnormal haemostatic activation and inflammation may help to elucidate some of the patho-physiology of the disease; primary preventative measures and targeted therapies at an early stage of the disease could then be considered. In the present paper we discuss potential causal links between PE, haemostasis and inflammation. The potential implications of such interaction on the pathogenesis of PE are also addressed.

Hemostatic changes in patients with end stage renal disease undergoing hemodialysis

Patients undergoing hemodialysis may show both thrombotic complications and bleeding abnormalities. Hemostatic changes in patients on hemodialysis may result from alterations in vessel wall integrity and platelet function, and reduced blood flow in the native arteriovenous fistula. Vascular complications represent 20-25% of all hospitalizations of patients on hemodialysis. Literature survey revealed that changes in the hemostatic system may play a major role in vascular complications observed in these patients. Thus, it is essential to investigate hemostatic alterations in patients on hemodialysis so that adequate regimes for anticoagulant therapy could be implemented. In this review we discuss hemostatic abnormalities in end stage renal disease patients undergoing hemodialysis.

Inflammation, neoangiogenesis and fibrosis in peritoneal dialysis

Peritoneal dialysis (PD) is a form of renal replacement therapy used in patients with end stage renal disease (ESRD). It is based on using the peritoneum as a semipermeable membrane through which ultrafiltration (UF) and diffusion occur. Despite several benefits, PD has long-term complications, including inflammation, neoangiogenesis and fibrosis. Several inflammatory molecules can be found in the dialysate of PD patients including: interleukins (IL), tumor necrosis factor α (TNF-α) and C-reactive protein (CRP). Angiogenesis results in increased effective surface area exchange. Consequently, the glucose-driven osmotic pressure of the peritoneal dialysis fluid (PDF) is significantly reduced leading to UF failure (UFF). Several factors are implicated in the development of peritoneal fibrosis (PF) in PD patients. The most important factor is the conventional bio-incompatible PD solution, which contains high concentration of glucose and glucose degradation products (GDP). Although there are several studies elucidating the mechanisms leading to UFF in PD patients, more studies needed to be developed in this area and more research is required to find mechanisms to delay or to minimize the occurrence of many deleterious changes in peritoneal membrane (PM) during PD.

Asymmetric Dimethylarginine (ADMA) in cardiovascular and renal disease

BACKGROUND Asymmetric Dimethylarginine (ADMA) is a modified amino acid formed when intracellular arginine is methylated by methyltransferases that are widely distributed throughout the body. Nitric oxide (NO) is produced from l-arginine in a reaction catalyzed by three distinct isoforms of NO synthase (NOS). NO has emerged as a mediator involved in maintenance of vascular tonus, blood pressure regulation, inhibition of platelet aggregation, leukocyte and endothelial cell interaction and vascular permeability. ADMA is an important inhibitor that competes with NOS and compromises NO synthesis. OBJECTIVE This review aims to compile articles involving renal and cardiovascular diseases in which plasma ADMA was assessed in order to clarify its role in these diseases. CONCLUSION Although current knowledge suggests that ADMA has a role in the onset of cardiovascular and renal diseases, its actions are poorly understood. Clarifying its biochemical mechanisms is essential for improving disease management and promoting better quality of life for these patients.

ApoB/ApoA-I ratio in young patients with ischemic cerebral stroke or peripheral arterial disease.

Although smoking and hypertension are classic risk factors for atherothrombotic diseases, the relationship of dyslipidemia and vascular diseases, other than myocardial infarction, is less clearly established, especially in young subjects. In the current study, a detailed analysis of the lipid and apolipoprotein profiles was conducted in young patients of ischemic cerebral stroke (IS) and peripheral arterial disease (PAD). Plasma levels of C-reactive protein (hs-CRP), total cholesterol (TC), high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), triglycerides (TG), and apolipoproteins A-I (ApoA-I) and apolipoproteins B (ApoB), which include the ApoB/ApoA-I ratio, were analyzed in a group of 81 patients who presented with IS (n = 46) or PAD (n = 35) as well as in 167 control subjects. Significant differences were observed for hs-CRP, TC, HDLc, LDLc, TG, ApoA-I, and ApoB levels, as well as for the ApoB/ApoA-I ratio, between the control and the IS or PAD groups. However, after adjustment for sex, age, smoking, hypertension, hs-CRP, and dyslipidemia (LDLc, TC, HDLc, TG, ApoA, ApoB, and ApoB/ApoA-I ratio), hs-CRP, ApoB, and the ApoB/ApoA-I ratio were independently associated with increased risks of IS or PAD. Increased ApoB/ApoA-I ratio and hs-CRP levels are independently associated with occurrence of IS and PAD in young patients and are significant markers of alterations on lipid and apolipoproteic profiles and inflammatory responses, respectively, in these patients.

Preeclampsia and ABO blood groups: a systematic review and meta-analysis

Preeclampsia (PE) is a multifactorial pregnancy-specific syndrome which represents one of the leading causes of maternal mortality worldwide. Inherited thrombophilia have been investigated as risk factor for the development of PE and it is currently known that ABO blood group may impact haemostatic balance, having the non-O blood groups (A, B or AB) subjects increased risk for thrombus formation, as compared to those of group O. We performed a systematic review of the literature for published studies investigating whether ABO blood groups could influence PE developing. A sensitive search of four databases identified 45 unique titles. The retrieved papers were assessed independently by authors and a rigorous process of selection and data extract was conduct. Methodological quality of the included studies was also evaluated. Two studies met eligibility criteria. As a main finding of our systematic review, an association between the AB blood group and the occurrence of PE was detected based on two original studies. Considering the role of ABO blood groups on the hemostatic process and thrombus formation, special attention should be given to pregnant patients carrying the AB blood group in order to prevent the syndrome and improve prognosis.

Fibrinolytic system in preeclampsia

Preeclampsia (PE) is a multi-system disorder of human pregnancy characterized by hypertension and proteinuria. Although its pathogenesis is not fully understood, predisposition to endothelial dysfunction is thought to play a crucial part. Normotensive pregnancy is associated with increases in coagulation factor levels and decreases in natural anticoagulation, leading to a hypercoagulable state. This state is thought to be part of a complex physiological adaptation, which ensures rapid and effective control of bleeding from the placental site at the time of placental separation. In PE, a more pronounced exacerbation of the hypercoagulable state is noticed, compared to normotensive pregnancy. Activation of coagulation in PE occurs at an early stage of the disease and often antedates the clinical symptoms. It is known that PE is associated with fibrin deposition in the kidney glomerulus, and in fatal cases, widespread fibrin deposition has been a prominent histological finding. Related to the fibrinolytic system in PE, the state of the art allows the assumption that blood coagulation overlaps the fibrinolytic regulatory mechanism, since fibrin deposition in maternal microcirculation is usually found in PE. However, there is still no consensus about its specific role. This review aims to discuss the fibrinolytic system in PE and its potential implications to the pathogenesis of this disease.

Acquired Pelger–Huët: What does it really mean?

Pelger-Huët anomaly (PHA) is a benign inherited condition characterized by hyposegmentation of the neutrophils nucleus and excessive chromatin clumping. An acquired neutrophil dysplasia similar to PHA has been described in hematological diseases and in some clinical conditions. It has been known as acquired or pseudo PHA. Although some hypotheses have been proposed to explain this phenomenon, the mechanism of nuclear change is still unclear. Only the laboratory and clinical data combined will yield a better understanding on the need for follow-up and management of patients in the appropriate cases. In addition, a possible cause of pseudo PHA must always be investigated to add insights to the full understanding of this abnormality. Whether this neutrophil phenomenon has clinical implications remains to be elucidated. It is clear that only a small number of patients under drugs (immunosuppressive and others) may present these neutrophil abnormalities. Most of them do not show this phenomenon and we are unable to explain the different responses in drug users. Whether these patients display a predisposition for developing bone marrow or other diseases in the future, it is a very intriguing matter and only a follow-up will solve this question.