Regular physical exercise improves walking performance in patients affected with peripheral obliterative arterial disease (POAD). The mechanisms underlying the phenomenon are still controversial. In order to verify the hypothesis that physical conditioning of lower limbs on a treadmill and ischemic preconditioning of the heart could share some biological aspects, 14 POAD subjects underwent a training program on the treadmill consisting of five repeated submaximal exercises at five-minute and two-hour intervals preceding the maximal tolerance test. Moreover, a protocol with two daily submaximal walking exercises over one week was also performed. Pain-free and total walking distance were measured before and after they performed the program. Moreover, plasma levels of adenosine and adenosine triphosphate (ATP) were measured and polymorphonuclear (PMN) leukocyte activity was studied together with rheologic parameters. Pain-free distance was prolonged by 15.4% and 14.3%, and total distance was prolonged by 23.1% and 26.9%, in the exercises with five-minute and two-hour intervals, respectively. After one week of daily exercises, the onset of pain and the end of the test were delayed by 24% and 43.7%, respectively. An improvement in blood rheology and a reduced PMN reactivity were also observed with the three protocols, associated with an increase in plasma levels of adenosine and ATP. Similarly to ischemic preconditioning in the heart, the possibility is suggested that an adenosine-mediated mechanism may contribute to the development of physical conditioning in treadmill-trained POAD patients.
IntroductionInflammatory myopathies (such as dermatomyositis and polymyositis) are well-recognized paraneoplastic syndromes. However, paraneoplastic necrotizing myopathy is a more recently defined clinical entity, characterized by rapidly progressive, symmetrical, predominantly proximal muscle weakness with severe disability, and associated with a marked increase in serum muscle enzyme levels. Paraneoplastic necrotizing myopathy requires muscle biopsy for diagnosis, which typically shows massive necrosis of muscle fibers with limited or absent inflammatory infiltrates.Case presentationWe report the case of an 82-year-old Italian-born Caucasian man who was admitted to hospital because of heart failure and two drop attacks. Over the following days, he developed progressive severe weakness, dysphagia, and dysphonia. Testing showed increasing serum muscle enzyme levels. Electromyography showed irritative myopathy of the proximal muscles and sensorimotor polyneuropathy. Muscle biopsy (left vastus lateralis) showed massive necrosis of muscle fibers with negligible inflammatory infiltrates, complement membrane attack complex deposition on endomysial capillaries, and moderate upregulation of major histocompatibility complex-I. Computed tomography of the thorax showed a nodular mass in the apex of the right lung. The patient was diagnosed with paraneoplastic necrotizing myopathy. In spite of high-dose corticoid therapy, he died 1 month later because of his aggressive cancer. Subsequent electron microscopic examination of a muscle biopsy specimen showed thickened walls and typical pipestem changes of the endomysial capillaries, with swollen endothelial cells. Poorly differentiated adenocarcinoma of the lung was confirmed on post-mortem histological examination.ConclusionsParaneoplastic necrotizing myopathy is a rare syndrome with outcomes ranging from fast progression to complete recovery. Treatment with corticosteroids is often ineffective, and prognosis depends mainly on the characteristics of the underlying cancer. This case shows that paraneoplastic necrotizing myopathy may have an atypical appearance, and should be considered in elderly patients with neoplastic disease. In this case, the diagnosis was delayed by the unusual clinical picture that suggested heart disease rather than muscle disease.
Twenty-four patients with vascular disorders, randomly divided into 3 dosage groups of 8 patients, were treated with a single oral dose of sulodexide (50, 100 or 200mg) and placebo. Tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1) activity and antigen, euglobulin lysis time, α2-antiplasmin, plasminogen, fibrinogen, blood and plasma viscosity, and whole blood filtration rate were determined before administration and over the following 24 hours. Sulodexide significantly increased t-PA activity linearly with the dose over the range of 50 to 200mg. At the same time, it also significantly decreased the concentration of PAI-1 linearly and proportionally with the dose. No clear effects were observed on the other monitored parameters, although euglobulin lysis time and plasma viscosity showed a tendency to decrease after the administration of sulodexide. These results justify the clinical activity of sulodexide. Indeed, the concomitant increase of t-PA and decrease of PAI-1 activity and antigen might increase the natural fibrinolytic activity with a physiological potentiation, without other adverse effects. The known activity of sulodexide in decreasing plasma viscosity during long term treatment is, however, not immediately explicable by the single-dose effects.
Pre-treatment with allopurinol is able markedly to attenuate the deterioration in blood viscosity (BV) and whole blood filterability (WBF) that occurs after ischaemia during exercise. It also reduces the exercise-induced increase in serum oxidase activity, although this action is slightly less effective in peripheral obliterative arterial disease (POAD) patients. Conversely, allopurinol is completely ineffective in modifying haemorheological parameters in vitro, and it does not affect superoxide anion generation or enzyme release from neutrophils stimulated in vitro with formyl-methionyl-leucyl-phenylalanine (FMLP). It is suggested that allopurinol may attenuate changes in BV and WBF by affecting xanthine-oxidase-dependent free radical formation in tissues.
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