Interleukin-1 alpha, soluble interleukin-2 receptor, and IgG concentrations in cystic fibrosis treated with prednisolone

The cytokines interleukin-1 and interleukin-2 participate in the inflammatory response, and may contribute to hypergammaglobulinaemia G and the development of lung injury in cystic fibrosis. Anti-inflammatory treatment with corticosteroids may attenuate this response. The effect of a 12 week course of oral prednisolone on spirometry and serum concentrations of interleukin-1 alpha (IL-1 alpha), soluble interleukin-2 receptor (sIL-2R), and IgG was investigated in 24 children with cystic fibrosis. Prednisolone was administered, in a double blind and placebo controlled manner, at an initial dose of 2 mg/kg daily for 14 days and tapered to 1 mg/kg on alternate days for 10 weeks. The treated group (n = 12) experienced an increase in forced expiratory volume in one second and forced vital capacity at 14 days, however, these changes were smaller at 12 weeks. In the treated group, change in pulmonary function was associated with decreased serum IgG and cytokine concentrations. Prednisolone suppresses serum concentrations of these cytokines, which may participate in the inflammatory response, the excessive synthesis of IgG, and airflow obstruction observed in cystic fibrosis patients.     

Peripheral α2-adrenoceptor-mediated sympathoinhibitory effects of mivazerol

Summary— Mivazerol is a new compound that could potentially reduce perioperative cardiovascular morbidity and mortality in patients with or at risk of coronary disease and submitted to surgery. This action of mivazerol depends on a well documented centrally mediated reduction in sympathetic nerve activity, but a direct peripheral decrease in sympathetic neurotransmitter release induced by activation of prejunctional α₂-adrenoceptors located on sympathetic nerve endings could also contribute. To investigate this issue, the effects of mivazerol on the pressor, systemic and regional hemodynamic (pulsed Doppler technique) as well as on the cardiac responses to electrical stimulation of the spinal cord (SCS) were measured in pithed rats in the absence and in the presence of mivazerol. Mivazerol exerted strong sympathoinhibitory effects: SCS-induced increases in blood pressure, total peripheral resistance and heart rate were dose-dependently reduced by mivazerol, but among the regional vascular beds investigated, only the hindlimb vasoconstrictor responses were significantly drug-affected. All these sympathoinhibitory effects of mivazerol were abolished by prior yohimbine administration. Simultaneously, mivazerol did not induce any postjunctional adrenoceptor blockade as it did not affect noradrenaline cardiac and hemodynamic effects. On the contrary, through postjunctional α₂-adrenoceptor stimulation, mivazerol, in this pithed preparation, dose-dependently increased blood pressure, total peripheral and hindlimb vascular resistances, but heart rate was not affected. We conclude that, in the pithed rat, mivazerol exerts strong peripheral sympathoinhibitory effects. The mechanism involved is prejunctional α₂-adrenoceptor activation as i) mivazerol does not display any postsynaptic α-adrenoceptor blocking effect — it even behaves as a postsynaptic α₂-adrenoceptor agonist — and ii) yohimbine abolishes mivazerol's sympathoinhibitory effects. Thus, direct peripheral together with central mechanisms contribute to mivazerol's sympathoinhibitory effects and ultimately to its cardioprotective action.     

Neuronal activity and information processing in motor control: from stages to continuous flow

Some years ago, we proposed, along with others, that the isomorphism between models of information processing by stages and the organization of neural pathways connecting functionally specialized neuronal networks was a guideline for conducting experiments in which the integration of methods and concepts of cognitive psychology and of neurophysiology was a promising approach to increase our knowledge of the processes responsible for motor control. At a time when models of serially organized information processing stages are being increasingly challenged, the deciphering of the underlying brain processes increasingly suggests that current views about the linkage between neural structures and behavioural functions must be reconsidered. First, at the "molar" level, the notion of a functional specialization of neuronal networks as, for example, being "sensory", "sensorimotor" or "motor", has to be viewed as a quantitative and not as a qualitative concept. Second, at the "molecular" level, the notion of a clear-cut functional differentiation between neuronal units, or between small sets of neurons, must similarly be revised: a neuron may be more or less "sensory" or "motor" and, moreover, may share both these functional properties to varying degrees. When the brain processes responsible for movement control are reconsidered in the light of these two concepts--that is a functional heterogeneity of structurally defined neuronal networks, as well as a continuum in functional specification of isolated neuronal units--data collected by using single-cell recording of neuronal activity fit well into the model of a continuous flow of information processing: neural pathways from the cortical parietal association areas to the corticospinal apparatus appear as a privileged sensorimotor information stream along which the amount of neuronal activity responsible for movement planning progressively decreases, while the amount of neuronal activity involved in movement execution progressively increases.     

Mechanisms of liver regeneration and their clinical implications

During the last few years there have been major advances in the understanding of the mechanisms of liver regeneration. These advances derived to a great extent from the increased use of transgenic and knockout mice. In parallel with the experimental work, human partial liver transplantation from cadavers and living donors continues to increase, stimulating hepatologists and surgeons to learn more about the mechanisms that regulate and promote regeneration. Thus, knowledge generated from laboratory work in rodents can be applied to clinical problems, while data on human transplantation can also guide the design of experimental work. In this review, we discuss a few selected aspects of liver regeneration that are of interest in both the laboratory and the clinic.     

Scintigraphic diagnosis of tricuspid regurgitation

The authors describe a simple technique for diagnosis of tricuspid regurgitation. Red blood cells were labeled in vivo with 99mTc and 22 patients were studied with ECG-gated blood-pool imaging of the liver. A single region of interest was manually drawn around the liver and a time-activity curve obtained. The per cent change in liver counts during the cardiac cycle was found to be significantly higher in the 12 patients with tricuspid regurgitation (Group I) (mean, 4.04 +/- 1.6%; range, 1.3-21.4%) compared with the 10 controls (Group II) (mean, 0.35 +/- 0.16%; range, 0.013-1.3%) (p less than 0.05). Using a 1% change in liver counts as the criterion of a positive study, all 12 cases in Group I were diagnosed correctly, but there was one false positive in Group II; thus the sensitivity was 100% and the specificity 90%.     

A prospective study of a focused, surgeon-performed ultrasound examination for the detection of occult common femoral vein thrombosis in critically ill patients

HYPOTHESIS: A focused, surgeon-performed ultrasound examination of the common femoral veins is an accurate screening tool for the detection of common femoral vein thrombosis in high-risk, critically ill patients. DESIGN: A prospective study using a focused ultrasound examination for findings consistent with deep vein thrombosis of the common femoral veins. The results of these examinations were compared with those of duplex imaging or computed tomographic venography studies. SETTING: Surgical intensive care unit. PATIENTS: All critically ill patients who were admitted to the surgical intensive care unit and considered to be at high risk for the development of deep vein thrombosis. MAIN OUTCOME MEASURE: Presence of deep vein thrombosis in the common femoral veins. RESULTS: During a 16-month period, surgeons performed 306 ultrasound examinations on 220 critically ill surgical patients. The results included 295 true negative, 9 true positive, 1 false negative, and 1 false positive, yielding a 90.0% sensitivity, 99.6% specificity, and 99.3% accuracy. CONCLUSION: A focused, surgeon-performed ultrasound examination is a rapid and accurate screening method to detect common femoral vein thrombosis in critically ill patients as well as to examine those patients in whom pulmonary embolism is strongly suspected.