The evaluation of patients with a bleeding tendency represents a challenge as the routinely available tests for evaluating bleeding disorders are limited, complicating the laboratory determination of the clinically observed bleeding tendency. As a result, some bleeding disorders remain undiagnosed. The aim of the study was to evaluate whether global coagulation tests would contribute to the laboratory analysis of patients with undiagnosed bleeding disorders. Patients were evaluated for coagulation and fibrinolysis activities by thrombin generation test and euglobulin lysis time. In addition, plasma activity of factor XIII, plasminogen, α-2 antiplasmin, plasminogen activator inhibitor-1, and thrombin-activatable fibrinolysis inhibitor was also obtained. Forty-five patients were included. Eight per cent presented a mild bleeding disorder and 20% a moderate bleeding disorder. The thrombin generation test results were similar between patients and controls. Euglobulin lysis time results, however, were lower in patients than in controls, both before (median 175 vs. 250 min, respectively; P = 0.003) and after (median 145 vs. 115 min, respectively; P ≤ 0.001) arm constriction, suggesting that they were experiencing hyperfibrinolysis. Interestingly, patients' median thrombin-activatable fibrinolysis inhibitor activity was higher than in controls (21.2 vs. 19.46 μg/ml; P = 0.016). However, plasminogen, α-2 antiplasmin, plasminogen activator inhibitor-1, and factor XIII activities did not differ between the groups. Global coagulation and fibrinolysis tests proved to be limited in detecting the hemostatic disorders in some patients with a relevant bleeding tendency and may not be adequate to address their bleeding risk. Bleeding scores are currently the available medical approach for the evaluation of these patients.

Subjects with chronic obstructive pulmonary disease (COPD) present breathing pattern and thoracoabdominal motion abnormalities that may contribute to exercise limitation. Twenty-two men with stable COPD (FEV 1 = 42.6 ± 13.5% predicted; age 68 ± 8 years; mean ± SD) on usual medication and with at least 5 years of diagnosis were evaluated at rest and during an incremental cycle exercise test (10 watts/2 min). Changes in respiratory frequency, tidal volume, rib cage and abdominal motion contribution to tidal volume and the phase angle that measures the asynchrony were analyzed by inductive respiratory plethysmography at rest and during three levels of exercise (30-50, 70-80, and 100% maximal work load). Repeated measures ANOVA followed by pre-planned contrasts and Bonferroni corrections were used for analyses. As expected, the greater the exercise intensity the higher the tidal volume and respiratory frequency. Abdominal motion contributed to the tidal volume increase (rest: 49.82 ± 11.19% vs exercise: 64.15 ± 9.7%, 63.41 ± 10%, and 65.56 ± 10.2%, respectively, P < 0.001) as well as the asynchrony [phase angle: 11.95 ± 7.24° at rest vs 22.2 ± 15° (P = 0.002), 22.6 ± 9° (P < 0.001), and 22.7 ± 8° (P < 0.001), respectively, at the three levels of exercise]. In conclusion, the increase in ventilation during exercise in COPD patients was associated with the major motion of the abdominal compartment and with an increase in the asynchrony independent of exercise intensity. It suggests that cycling exercise is an effective way of enhancing ventilation in COPD patients.

Background: The causes for venous thromboembolism (VTE) remain undetermined in at least 30% of patients with unprovoked VTE. Hypofibrinolysis may be associated to VTE, however the occurrence of hypofibrinolysis in patients with unprovoked, idiopathic, VTE is not well stablished. Aims: To evaluate whether hypofibrinolysis would be associated with unprovoked idiopathic VTE. Methods: Patients with a history of unprovoked VTE without acquired or inherited thrombophilia were included. Global tests of fibrinolysis, such as euglobolin lysis time (ELT) and lysis area on fibrin plate (LAFP), and specific tests of fibrinolysis, such as plasma activity plasminogen, a-2 antiplasmin (a2AP), plasminogen activator inhibitor-1 (PAI-1), and thrombin activatable fibrinolysis inhibitor (TAFI), were performed in patients and healthy controls. We also analyzed the plasma activity of factor (F) XIII. Results: Thirty-one patients and fifty healthy controls were included. ELT results were higher in patients than in controls (median= 295 and IQ= 205-355 minutes vs. median=250 and IQ= 167-295 minutes, respectively, p = 0.006) and LAFP values were lower in patients compared to controls (median=81 and IQ= 56-110 vs. median= 95 and IQ 72-132 respectively, p = 0.0014), suggesting that they were experiencing a hypofibrinolytic state. Plasma activity of plasminogen (median= 131 and IQ= 119-141 vs. median=120 and IQ=111-137, respectively, p = 0.045) and FXIII (median= 103 and IQ 89-127 vs. median= 96 and IQ=80-105, respectively, p = 0.050), were higher in patients than in controls, whereas plasma activity of α-2AP was lower in patients (median= 124 and IQ 114-128 vs. median= 127 and IQ=121-133, p≤0.001). Interestingly, patient's median TAFI activity was lower than in controls (median=16 and IQ 13-18μg/mL vs. median= 19 and IQ= 17-21g/mL, p≤0.001). However, PAI-1 activity did not differ between groups. Conclusions: Hypofibrinolysis may occur in patients with unprovoked idiopathic VTE and may be detected by global tests of fibrinolysis. It is possible that hypofibrinolysis contribute to the pathogenesis of thrombosis in these selected cases. Disclosures No relevant conflicts of interest to declare.

A nanotecnologia está presente na humanidade acerca de dois mil anos. Inicialmente usada de forma empírica, ao longo dos anos, com o interesse público, seu uso foi racionalizado de maneira sistemática e precisa. Essa ferramenta enquadra tecnologias e processos que manipulam ou exploram estruturas nanométricas em busca de propriedades físico-químicas e comportamentais diferentes daquelas apresentadas em escalas maiores, possibilitando a criação de materiais, substâncias, produtos, dispositivos e sistemas que podem ser aplicados de forma multi e interdisciplinar. Em acelerado e intenso crescimento, a nanotecnologia tem alcançado investimentos vultuosos em todo o mundo, e o Brasil é um dos países que tem investido sua economia nessa tecnologia e, que hoje, possui prioridade de depósito de patentes relacionadas à nanobiotecnologia. Essa ciência inovadora tem permitido significativos avanços em diversas áreas que, não sendo novas, começam a ser reinventadas. Assim, a nanotecnologia está emergindo como a próxima revolução tecnológica, com eventuais efeitos sobre todos os aspectos da vida, sendo que, independente do segmento, há o consenso de que o crescimento da capacidade da construção molecular mudará profundamente o mundo atual.