O uso de drogas anticoagulantes e antiplaquetárias orais em pacientes cirúrgicos ambulatoriais: revisão de literatura

The oral anticoagulants (AOC) and platelet antiagregants are drugs used for the prevention of thromboembolic phenomena, such as pulmonary embolism in patients with atrial fribrilation heart valves, thrombosis and pulmonary embolism. For patients who are undergoing surgical procedures-dentistry were asked to discontinue the use of anticoagulants until the value of the INR remained = 2.0, that in order to avoid trans and hemorrhages in the postoperative period. However, the AOC can cause the formation of a clot, leading to obstruction of blood pathways. Thus, it became doubtful the medicine for surgery, in which local hemostatic measures would be sufficient to promote hemostasis. Thus, the objective of the review was to evaluate the risk of bleeding in patients AOC users that are subjected to surgical procedures, through a bibliographical survey carried out in relevant clinical studies published between 1990 and 2012, by the MedlinePubMed data. In this review of literature was concluded that the benefit of thromboembolism prevention overcomes the risk hemorrhage, therefore, it is recommended to keep the dose of anticoagulant therapy unchanged for patients undergoing oral surgery and implant dentistry, using appropriate INR levels with the assistance of local hemostatic. In addition, a refined surgical technique should be performed in these patients. With respect to the most invasive oral surgery, with a risk of bleeding, treatment may be necessary in conjunction with the medical staff.

STATUS OF BROMETHALIN OUTSIDE THE UNITED STATES

ABSTRACT: Bromethalin has been extensively researched over the past decade in the United States, Switzerland, England, Denmark, and France. United States EPA registrations were received in 1982 and commercial pelleted formulations containing 0.01% bromethalin were developed and introduced in the USA by Ralston Purina (ASSAULT1*) in 1985 and Velsicol (VENGEANCE1*) in 1986. Ciba-Geigy is currently developing new formulations under the tradename DORATIDR for use outside the United States. Bromethalin acute toxicity and 14-day subchronic studies are reviewed and data from recently completed 90-day subchronic studies required for registration outside the US are presented. Pharmacodynamic studies have shown that bromethalin acts as an uncoupler of oxidative phosphorylation, thus interrupting the vital production of ATP necessary to maintain essential metabolic functions. Laboratory and field trial data are presented from Switzerland, France, England, and Denmark that indicate the effectiveness of new bromethalin formulations against anticoagulant resistant and susceptible rodents. A comparative rodenticide pen testing system is described from which test results confirm bromethalin's quick action and feed consumption efficiency when compared to second-generation anticoagulants.

COMMENSAL RODENT CONTROL

SUMMARY: Federal Urban Rat Control Program grants were awarded to cities in different areas of the United States. Severe problems of rat infestations have been detected in many of the cities by the Environmental Health Service. Approximately 20% of 3.8 million people in the project areas were occupying homes infested with rats. Control operations are now in effect in all cities, and the living conditions of the people have been substantially improved. An increase in interest in rodent control also is evident in countries outside of the United States. The Technical Development Laboratories of the National Communicable Disease Center are participating in the World Health Organization program of research on new rodenticides. The evaluation program involves five steps which carry a candidate toxi¬cant from laboratory phase through field testing. Acceptability and suitable concentrations of both acute and accumulative rodenticides are determined. Observations are made on the hazard of the compound to pets and to other nontarget vertebrates. Laboratory and field studies have been completed on a new, promising stabilized scilliroside glycoside which has given excellent control of the Norway rat in 16 out of 19 premises. Another new coded compound has shown a unique specificity for roof rats as compared to Norway rats. Although anticoagulant resistant rat populations have occurred in several countries in Europe, as yet no evidence has been noted of such resistance in rats in the United States.

Um novo protocolo in silico para a predição de complexos flexíveis entre proteínas: estudo de caso para inibidores plasmáticos de fosfolipase A2 de serpentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Plasmodium vivax Duffy binding protein: baseline antibody responses and parasite polymorphisms in a well-consolidated settlement of the Amazon Region

Objective To investigate risk factors associated with the acquisition of antibodies against Plasmodium vivax Duffy binding protein (PvDBP) a leading malaria vaccine candidate in a well-consolidated agricultural settlement of the Brazilian Amazon Region and to determine the sequence diversity of the PvDBP ligand domain (DBPII) within the local malaria parasite population. Methods Demographic, epidemiological and clinical data were collected from 541 volunteers using a structured questionnaire. Malaria parasites were detected by conventional microscopy and PCR, and blood collection was used for antibody assays and molecular characterisation of DBPII. Results The frequency of malaria infection was 7% (6% for P. vivax and 1% for P. falciparum), with malaria cases clustered near mosquito breeding sites. Nearly 50% of settlers had anti-PvDBP IgG antibodies, as detected by enzyme-linked immunosorbent assay (ELISA) with subjects age being the only strong predictor of seropositivity to PvDBP. Unexpectedly, low levels of DBPII diversity were found within the local malaria parasites, suggesting the existence of low gene flow between P. vivax populations, probably due to the relative isolation of the studied settlement. Conclusion The recognition of PvDBP by a significant proportion of the community, associated with low levels of DBPII diversity among local P. vivax, reinforces the variety of malaria transmission patterns in communities from frontier settlements. Such studies should provide baseline information for antimalarial vaccines now in development.

Lufaxin, a Novel Factor Xa Inhibitor From the Salivary Gland of the Sand Fly Lutzomyia longipalpis Blocks Protease-Activated Receptor 2 Activation and Inhibits Inflammation and Thrombosis In Vivo

Objective-Blood-sucking arthropods' salivary glands contain a remarkable diversity of antihemostatics. The aim of the present study was to identify the unique salivary anticoagulant of the sand fly Lutzomyia longipalpis, which remained elusive for decades. Methods and Results-Several L. longipalpis salivary proteins were expressed in human embryonic kidney 293 cells and screened for inhibition of blood coagulation. A novel 32.4-kDa molecule, named Lufaxin, was identified as a slow, tight, noncompetitive, and reversible inhibitor of factor Xa (FXa). Notably, Lufaxin's primary sequence does not share similarity to any physiological or salivary inhibitors of coagulation reported to date. Lufaxin is specific for FXa and does not interact with FX, Dansyl-Glu-Gly-Arg-FXa, or 15 other enzymes. In addition, Lufaxin blocks prothrombinase and increases both prothrombin time and activated partial thromboplastin time. Surface plasmon resonance experiments revealed that FXa binds Lufaxin with an equilibrium constant approximate to 3 nM, and isothermal titration calorimetry determined a stoichiometry of 1:1. Lufaxin also prevents protease-activated receptor 2 activation by FXa in the MDA-MB-231 cell line and abrogates edema formation triggered by injection of FXa in the paw of mice. Moreover, Lufaxin prevents FeCl3-induced carotid artery thrombus formation and prolongs activated partial thromboplastin time ex vivo, implying that it works as an anticoagulant in vivo. Finally, salivary gland of sand flies was found to inhibit FXa and to interact with the enzyme. Conclusion-Lufaxin belongs to a novel family of slow-tight FXa inhibitors, which display antithrombotic and anti-inflammatory activities. It is a useful tool to understand FXa structural features and its role in prohemostatic and proinflammatory events. (Arterioscler Thromb Vasc Biol. 2012;32:2185-2196.)

Defibrotide Interferes With Several Steps of the Coagulation-Inflammation Cycle and Exhibits Therapeutic Potential to Treat Severe Malaria

Objective-The coagulation-inflammation cycle has been implicated as a critical component in malaria pathogenesis. Defibrotide (DF), a mixture of DNA aptamers, displays anticoagulant, anti-inflammatory, and endothelial cell (EC)-protective activities and has been successfully used to treat comatose children with veno-occlusive disease. DF was investigated here as a drug to treat cerebral malaria. Methods and Results-DF blocks tissue factor expression by ECs incubated with parasitized red blood cells and attenuates prothrombinase activity, platelet aggregation, and complement activation. In contrast, it does not affect nitric oxide bioavailability. We also demonstrated that Plasmodium falciparum glycosylphosphatidylinositol (Pf-GPI) induces tissue factor expression in ECs and cytokine production by dendritic cells. Notably, dendritic cells, known to modulate coagulation and inflammation systemically, were identified as a novel target for DF. Accordingly, DF inhibits Toll-like receptor ligand-dependent dendritic cells activation by a mechanism that is blocked by adenosine receptor antagonist (8-p-sulfophenyltheophylline) but not reproduced by synthetic poly-A, -C, -T, and -G. These results imply that aptameric sequences and adenosine receptor mediate dendritic cells responses to the drug. DF also prevents rosetting formation, red blood cells invasion by P. falciparum and abolishes oocysts development in Anopheles gambiae. In a murine model of cerebral malaria, DF affected parasitemia, decreased IFN-gamma levels, and ameliorated clinical score (day 5) with a trend for increased survival. Conclusion-Therapeutic use of DF in malaria is proposed. (Arterioscler Thromb Vasc Biol. 2012; 32:786-798.)

Association of arterial events with the coexistence of metabolic syndrome and primary antiphospholipid syndrome

Objective Metabolic syndrome (MetS) is highly prevalent in rheumatic diseases and is recognized as a new independent cardiovascular risk factor. This study was undertaken to determine the clinical significance of MetS in patients with primary antiphospholipid syndrome (APS). Methods Seventy-one primary APS patients and 73 age- and sex-matched healthy controls were included. Serum samples were tested for lipid profile, Lp(a), glucose, insulin, thyroid-stimulating hormone, free T4, erythrocyte sedimentation rate, C-reactive protein level, and uric acid. MetS was defined by the International Diabetes Federation criteria, and insulin resistance was established using the homeostasis model assessment index. Results The prevalence of MetS was 33.8%, and further comparison between primary APS patients with and without MetS revealed that the former had a higher frequency of arterial events (79.2% versus 42.6%; P = 0.003), angina (29.2% versus 2.1%; P = 0.002), and positive lupus anticoagulant antibody (95.8% versus 76.6%; P = 0.049). In addition, primary APS patients with MetS, as expected, had a higher prevalence of cardiovascular risk factors. On multivariate analysis, only MetS was independently associated with arterial events in primary APS. Conclusion Coexistence of primary APS and MetS seems to identify a subgroup of patients with higher risk of arterial events, suggesting that MetS may aggravate existing endothelial abnormalities of primary APS.

Chemical reduction of carboxyl groups in heparin abolishes its vasodilatory activity

Previous studies have shown that heparin induces vascular relaxation via integrin-dependent nitric oxide (NO)-mediated activation of the muscarinic receptor. The aim of this study was to identify the structural features of heparin that are necessary for the induction of vasodilatation. To address this issue, we tested heparin from various sources for their vasodilatation activities in the rat aorta ring. Structural and chemical characteristics of heparin, such as its molecular weight and substitution pattern, did not show a direct correlation with the vasodilation activity. Principal component analysis (PCA) of circular dichroism (CD), 1H-nuclear magnetic resonance (NMR) and vasodilation activity measurements confirmed that there is no direct relationship between the physico-chemical nature and vasodilation activity of the tested heparin samples. To further understand these observations, unfractionated heparin (UFH) from bovine intestinal mucosa, which showed the highest relaxation effect, was chemically modified. Interestingly, non-specific O- and N-desulfation of heparin reduced its anticoagulant, antithrombotic, and antihemostatic activities, but had no effect on its ability to induce vasodilation. On the other hand, chemical reduction of the carboxyl groups abolished heparin-induced vasodilation and reduced the affinity of heparin toward the extracellular matrix (ECM). In addition, dextran and dextran sulfate (linear non-sulfated and highly sulfated polysaccharides, respectively) did not induce significant relaxation, showing that the vasodilation activity of polysaccharides is neither charge-dependent nor backbone unspecific. Our results suggest that desulfated heparin molecules may be used as vasoactive agents due to their low side effects. J. Cell. Biochem. 113: 13591367, 2012. (c) 2011 Wiley Periodicals, Inc.

Systemic sclerosis sine scleroderma associated with antiphospholipid syndrome

The antiphospholipid syndrome (APS) can be primary, when it occurs alone, or secondary, when it is associated with another autoimmune disease, mainly systemic lupus erythematosus and rarely other autoimmune diseases. Cases described in literature (Medline 1966 to December 2009) associate the presence of antiphospholipid antibodies with the presence of APS and systemic sclerosis (SS). Currently, however, no cases of the SS variant sine scleroderma with APS have been described. In this study, the authors describe the case of a patient with APS characterised by thrombosis of the retinal veins, in May 2006, the presence of lupus anticoagulant and an anticardiolipin IgG antibody. In May 2007, this patient developed Raynaud's phenomenon, a lack of oesophageal motility and nailfold capillaroscopy with a scleroderma pattern. The patient was positive for the anti-centromere antibody but lacked any evidence of cutaneous thickening or involvement. In summary, the authors describe the first case of a patient with APS associated with SS sine scleroderma.

Chorea in primary antiphospholipid syndrome is associated with rheumatic fever

The aim of the study is to evaluate the frequency of chorea in a cohort of primary antiphospholipid syndrome (PAPS) patients and their possible clinical and laboratory associations. The records of 88 PAPS patients, fulfilling Sapporo criteria, followed up at the rheumatology outpatient clinic, were analyzed in order to determine the frequency of chorea. Risk factors for chorea, clinical manifestations, associated comorbidities, serologic features and treatment strategies were analyzed. Eighty-eight PAPS patients were evaluated. Mean age was 40.6 +/- A 11.1 years, and 91% of them were Caucasian and 91% women. Four (4.5%) patients with chorea were identified: 2 of them (50%) had only one chorea episode and 2 (50%) had recurrent chorea. All patients had chorea onset before PAPS diagnosis. Mean age, gender and ethnical distribution were comparable in groups with or without seizures (P > 0.05). Interestingly, the comparison of the 4 PAPS patients with chorea with those without this abnormality (n = 84) demonstrated a lower BMI [21.1 (18-24.2) vs. 27.5 (17.5-40.9) kg/m(2), P = 0.049] and frequency of venous events (0 vs. 63.1%, P = 0.023) in the first group. A higher frequency of rheumatic fever (75% vs. 0, P < 0.001) and thrombocytopenia (75 vs. 21.4%, P = 0.041) was observed in PAPS individuals with chorea. Both groups were alike regarding the other clinical APS manifestations, disease duration, risk factors for cerebrovascular diseases, use of drugs and antiphospholipid antibodies (P > 0.05). This study demonstrated that 4.5% of PAPS patients had chorea, predominately before PAPS diagnosis, and this neurological abnormality was associated with rheumatic fever and thrombocytopenia. These data reinforce the need for RF diagnosis in those PAPS patients with chorea.

Antiphospholipid syndrome plus rheumatic fever: a higher risk factor for stroke?

To compare clinical and laboratory findings between patients with primary antiphospholipid syndrome (PAPS) versus secondary APS due to rheumatic fever (APS-RF) (according to Jones criteria). Seventy-three APS patients (Sapporo criteria) were enrolled, and demographic, clinical, and laboratory data were collected. Exclusion criteria were heart congenital abnormalities and previous infectious endocarditis. Patients were divided into two groups: PAPS (n = 68) and APS-RF (n = 5). The mean current age, disease duration, frequencies of female gender, and Caucasian race were similar in APS-RF and PAPS patients (P > 0.05). Remarkably, the frequency of stroke was significantly higher in APS-RF compared to PAPS patients (80% vs. 25%, P = 0.02). Of note, echocardiogram of these patients did not show intracardiac thrombus. No significant differences were found in peripheral thromboembolic events (P = 1.0), pulmonary thromboembolism (P = 1.0), miscarriage (P = 0.16), thrombocytopenia (P = 0.36), arterial events (P = 0.58), and thrombosis of small vessels (P = 1.0). There were no differences in the frequencies of comorbidities such as diabetes mellitus, hypertension, smoking, and hyperlipidemia in both groups (P > 0.05). The frequencies of lupus anticoagulant, IgG, and IgM anticardiolipin were similar in two groups. APS patients associated with rheumatic fever without infective endocarditis may imply a high stroke risk as compared with PAPS, and future studies are needed to confirm this finding.

Autoimmune disease and multiple autoantibodies in 42 patients with RASopathies

The association of RASopathies [Noonan syndrome (NS) and Noonan-related syndromes] and autoimmune disorders has been reported sporadically. However, a concomitant evaluation of autoimmune diseases and an assessment of multiple autoantibodies in a large population of patients with molecularly confirmed RASopathy have not been performed. The clinical and laboratory features were analyzed in 42 RASopathy patients, the majority of whom had NS and five individuals had Noonan-related disorders. The following autoantibodies were measured: Anti-nuclear antibodies, anti-double stranded DNA, anti-SS-A/Ro, anti-SS-B/La, anti-Sm, anti-RNP, anti-Scl-70, anti-Jo-1, anti-ribosomal P, IgG and IgM anticardiolipin (aCL), thyroid, anti-smooth muscle, anti-endomysial (AE), anti-liver cytosolic protein type 1 (LC1), anti-parietal cell (APC), anti-mitochondrial (AM) antibodies, anti-liver-kidney microsome type 1 antibodies (LKM-1), and lupus anticoagulant. Six patients (14%) fulfilled the clinical criteria for autoimmune diseases [systemic lupus erythematous, polyendocrinopathy (autoimmune thyroiditis and celiac disease), primary antiphospholipid syndrome (PAPS), autoimmune hepatitis, vitiligo, and autoimmune thyroiditis]. Autoimmune antibodies were observed in 52% of the patients. Remarkably, three (7%) of the patients had specific gastrointestinal and liver autoantibodies without clinical findings. Autoimmune diseases and autoantibodies were frequently present in patients with RASopathies. Until a final conclusion of the real incidence of autoimmunity in Rasopathy is drawn, the physicians should be alerted to the possibility of this association and the need for a fast diagnosis, proper referral to a specialist and ultimately, adequate treatment. (c) 2012 Wiley Periodicals, Inc.

US Food and Drug Administration approval of generic versions of complex biologics: implications for the practicing physician using low molecular weight heparins

Low-molecular-weight heparins (LMWHs) have shown equivalent or superior efficacy and safety to unfractionated heparin as antithrombotic therapy for patients with acute coronary syndromes. Each approved LMWH is a pleotropic biological agent with a unique chemical, biochemical, biophysical and biological profile and displays different pharmacodynamic and pharmacokinetic profiles. As a result, LMWHs are neither equipotent in preclinical assays nor equivalent in terms of their clinical efficacy and safety. Previously, the US Food and Drug Administration (FDA) cautioned against using various LMWHs interchangeably, however recently, the FDA approved generic versions of LMWH that have not been tested in large clinical trials. This paper highlights the bio-chemical and pharmacological differences between the LMWH preparations that may result in different clinical outcomes, and also reviews the implications and challenges physicians face when generic versions of the original/innovator agents are approved for clinical use.

Thrombocytopenia and platelet activity in dogs experimentally infected with Rangelia vitalii

The aim of this study was to evaluate the platelet count, coagulation time and platelet activity in dogs experimentally infected with Rangelia vitalii during the acute phase of the disease. For this study, 12 young dogs (females) were used, separated in two groups. Group A (uninfected control) was composed by healthy dogs (n=5), and group B consisted of R. vitalii-infected animals (n=7). After being inoculated with R. vitalii-infected blood, animals were monitored by blood smear examinations, which showed intra-erythrocytic forms of the parasite five days post-inoculation (PI). Blood samples were collected on days 0, 10, 20 and 30 PI. The material collected was placed in tubes containing EDTA for quantification of platelets, citrate anticoagulant platelet aggregation, and measuring the clotting time. Right after blood collection on days 10 and 20 PI, dogs were anesthetized for collecting bone marrow samples. A significant reduction (P<0.01) of the number of platelets was observed in R. vitalii-infected blood, when compared with uninfected dogs on days 10 and 20 PI. Additionally, macro-platelets were observed only in infected dogs. Prothrombin time and activated partial thromboplastin time did not differ between infected and uninfected dogs. The megakaryocyte count increased (P<0.01) significantly in infected dogs when compared with uninfected ones on days 10 and 20 PI. Platelet aggregation decreased (P<0.01) significantly in infected dogs in comparison to the control on days 10 and 20 PI. Therefore, rangeliosis in dogs causes a severe thrombocytopenia during the acute phase of infection. This platelets reduction probably occurred due to splenic sequestration and/or immune-mediated thrombocytopenia. (C) 2011 Elsevier B.V. All rights reserved.