Half-dose recombinant tissue plasminogen activator treatment in venous thromboembolism.

INTRODUCTION: Pulmonary embolism (VTE) comes in different degrees of severity from massive pulmonary embolism to nonmassive pulmonary embolism with no symptoms or hypoxia. Thrombolytic therapy is a lifesaver especially for patients who are in the high-risk group. In this study, we aimed at evaluating symptoms and clinical and laboratory findings in patients who had a diagnosis of massive or submassive VTE and treated with 50-mg recombinant tissue plasminogen activator (rt-PA) per hour for various problems as opposed to the standard dose, which is 100 mg every 2 hours. MATERIALS AND METHODS: Forty-six patients with a diagnosis of massive or submassive VTE who received thrombolytic therapy were evaluated retrospectively. Twenty-three patients who were treated with 50-mg rt-PA per hour were included in the study group. On the other hand, 23 patients who were treated with 100 mg of intravenous infusion of rt-PA every 2 hours were included in the control group. Echocardiographic assessment of the right ventricular size, systolic pulmonary artery pressure (sPAP), oxygen saturation, systemic arterial pressure, and heart rate before the thrombolytic therapy and in the first 24 hours after the administration of therapy were checked and noted in both of the groups. RESULTS: No significant difference was found between the 2 groups with regard to demographic data, Wells scores, type of embolism, average symptom duration, sPAP, and oxygen saturation. Differences in recovery, as inferred from vital symptoms and sPAP measurements, were not significant between the 2 groups. CONCLUSIONS: Lower-dose thrombolytic therapy showed similar efficacy versus the standard dose in VTE. Thrombolytic therapy is a life-saving treatment in massive VTE. Furthermore, a harm/benefit analysis may lead to the administration of half-dose therapy in selected cases when it is contraindicated for various reasons.

The role of oxidative stress in bronchoconstriction due to occupational sulfur dioxide exposure.

BACKGROUND: We previously showed that apricot sulfurization workers (ASW) are exposed to high concentrations of SO(2), resulting in an asthma-like syndrome. The aim of this study was to evaluate whether oxidative stress plays a role in the pathogenesis of asthma-like syndrome due to the high concentrations of SO(2) exposure in agricultural environment. METHODS: Serum antioxidant enzyme activities and malondialdehyde (MDA) concentrations, which are markers of lipid peroxidation, and pulmonary function tests (PFT) were measured in 40 volunteer ASW and compared to 20 healthy control subjects. RESULTS: The superoxide dismutase (SOD, 2.2+/-0.6 vs. 3.2+/-0.7 U/ml), glutathione peroxidase (GSH-Px, 0.6+/-0.3 vs. 1.1+/-0.3 U/ml) and catalase (107.6+/-27.4 vs. 152.6+/-14.3 k/l) activities in ASW were significantly (p<0.0001) lower than controls, whereas the malondialdehyde concentration (4.1+/-0.9 vs. 1.9+/-5.3 nmol/l) was higher in ASW (p<0.0001). ASW had significant decreases in pulmonary function parameters after exposure. CONCLUSION: These results show that occupational exposure to high concentrations of SO(2) enhances oxidative stress and lipid peroxidation may be considered as a new mechanism of SO(2)-induced bronchoconstriction.