Pflügers Archiv : European journal of physiology
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The aim of the present study was to test the sensitivity of different classes of sensory axons to lidocaine 2 and 4% nerve block. The basic approach was to examine changes in compound action potential (CAP) of A and C axons of the rat sural nerve induced by 2 or 4% lidocaine nerve block in vitro. CAP in control sural nerves (n = 6 for each experimental group) before nerve block was induced, consisted of the early component (A axons: 0.3 +/- 0.02 ms) and the late component (C axons: 12.2 +/- 1.14 ms) with peak voltage amplitudes 4.4 +/- 1.4 mV and 0.04 +/- 0.02 mV, respectively. ⋯ However, 4% lidocaine did not affect the maximal depression of CAP of sensory A axons. These results support the view, that C axons are more sensitive to lidocaine nerve block than A axons. In addition, our results suggest a population of sensory A axons which is non-sensitive to 2% and 4% lidocaine.
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We studied the value of serum interleukin-8 (IL-8) and procalcitonin (PCT) in the early diagnosis of early severe bacterial infection in 58 critically ill ventilated neonates. ELISA was used for determining IL-8 and immunoluminometric assay for PCT. IL-8 and PCT were compared with routinely used serum C-reactive protein (CRP). ⋯ There was no difference between group Ia+b and group III except for CRP at 24 h. Diagnostic accuracy was best for PCT on admission and for CRP at 24 h. Serum PCT and IL-8 are not specific markers for early severe bacterial infection in critically ill neonates and are not better than CRP.
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The sensitivity of different classes of peripheral nerve fibres to anaesthesia with sodium pentobarbital in rat was tested. The basic approach was to examine changes in compound action potential (CAP) in a rat sural nerve induced by sodium pentobarbital. Rats were either sacrificed by cervical dislocation (control) or anaesthetized with sodium pentobarbital (100 mg/kg, i.p.), and a 30 mm long sural nerve segment excised and placed on electrodes in a thermostatically controlled recording chamber. ⋯ However, the amplitude of CAP of both A and C axons was reduced by approximately 40% and 50%, respectively. The depressant effect of pentobarbital on CAPs was statistically significant for both groups of axons (p<0.01). Non-selective sensitivity of A and C axons to pentobarbital suggests even distribution of receptors for GABA in these two populations of axons in the rat peripheral nerve.
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Leukocytes adhering to venular endothelium and emigrating into the tissue contribute to myocardial reperfusion injury. The aim of the present study was to characterize the contribution of two different families of adhesion molecules, selectins and integrins, to post-ischaemic capillary plugging and venular adhesion of leukocytes in an isolated heart model. Guinea-pig hearts were perfused using the Langendorff technique. ⋯ The increase in PMN adhesion to venular endothelium was blocked completely by pretreatment with fucoidin (19 +/- 5 PMN/mm-2) or CD18 antibody (7 +/- 2 PMN/mm-2). We conclude that selectin interaction alone is not sufficient to account for post-ischaemic PMN adhesion in the small venules of the coronary vasculature, because blocking the integrin subunit CD18 also inhibited PMN adhesion completely. On the other hand, neither integrins nor selectins seem to be involved in post-ischaemic capillary plugging by PMN in our perfused heart model.
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Chloride channels perform important roles in the regulation of cellular excitability, in transepithelial transport, cell volume regulation, and acidification of intracellular organelles. This variety of functions requires a large number of different chloride channels that are encoded by genes belonging to several unrelated gene families. The CLC family of chloride channels has nine known members in mammals that show a differential tissue distribution and function both in plasma membranes and in intracellular organelles. ⋯ They probably function as dimers and may have two pores. The functional expression of channels altered by site-directed mutagenesis has led to important insights into their structure-function relationship. Their physiological relevance is obvious from three human inherited diseases (myotonia congenita, Dent's disease and Bartter's syndrome) that result from mutations in some of their members and from a knock-out mouse model.