Treatment of myofascial trigger points in common shoulder disorders by physical therapy: A randomized controlled trial [ISRCTN75722066]

Background  

Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders.     

A rational approach to recurrent carotid stenosis

To further characterize the incidence and morbidity of recurrent carotid stenosis, we reviewed 184 consecutive carotid endarterectomies performed in a university hospital between August 1983 and January 1988, in patients followed after operation with serial duplex ultrasonography. Recurrent stenosis of greater than 50% diameter reduction developed in eleven arteries (6.0%) at a mean interval of 10.2 +/- 7.8 months. Three of the eleven (1.6% of the total) had associated transient ischemic attack, and none had strokes. Restenosis was significantly more frequent in diabetic patients than in nondiabetic patients (13.3% vs 4.5%; p less than 0.05); and among patients whose primary stenoses had been symptomatic compared to asymptomatic (11.0% vs 1.5%; p less than 0.02). No statistically significant association with restenosis could be established for gender, hypertension, or smoking. Completion angiography and/or Doppler spectral analysis had been performed, and results were normal at the primary operation in 10 of the 11 patients. Only six of 184 arteries (3.3%) had vein patch closure, but none of these restenosed. Uneventful reoperation with patch closure was performed in three patients with transient ischemic attacks and two with preocclusive restenoses. Lesions were myointimal hyperplasia in four and atheroma in one. Three of the unoperated restenoses have shown regression on duplex scanning, but a fourth progressed to asymptomatic occlusion. Carotid restenosis is uncommon, even without routine use of vein patch angioplasty. Reoperation should be reserved for patients with associated symptoms or greater than 80% restenosis.     

L-arginine reverses the antinatriuretic effect of cyclosporin in renal transplant patients

BACKGROUND: Cyclosporin has been shown to facilitate renal vasoconstriction and to have an antinatriuretic effect. The existence of an interference of cyclosporin with the vasodilating properties of endothelium mediated by nitric oxide production could mediate these effects. On the other hand, the infusion of the nitric oxide precursor L-arginine has been shown to induce renal vasodilatation and to facilitate natriuresis in normal volunteers. We have investigated the renal effects of the administration of an infusion of L-arginine in renal transplant patients chronically treated with cyclosporin. To facilitate the analysis of the data the effects of the administration of a similar dose of cyclosporin on renal function during the infusion of a vehicle were also investigated during the administration of a vehicle of L-arginine. DESIGN: Ten male renal transplant patients, chronically treated with cyclosporin and with a stable renal function were studied during 2 consecutive days after the administration of the usual morning dose of cyclosporin. The first day they received an intravenous infusion of vehicle and the second the infusion of graded doses of L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h. RESULTS: The first day, after cyclosporin administration a significant fall (P < 0.01) was observed in natriuresis and kaliuresis in the absence of changes in renal plasma flow and glomerular filtration rate. After the administration of L-arginine significant (P < 0.01) increases of renal plasma flow, glomerular filtration rate, and natriuresis were seen. The increase in blood levels of cyclosporin after its administration did not differ between days 1 and 2. CONCLUSION: These results indicate that L-arginine facilitates renal vasodilatation and natriuresis in renal transplant patients. Furthermore, the observed increase in sodium excretion could indicate that L-arginine counteracts the antinatriuretic effect of cyclosporin.      

Regulation of synaptic inputs to paraventricular-spinal output neurons by alpha2 adrenergic receptors

Neurons in the paraventricular nucleus (PVN) that project to the brain stem and spinal cord are important for autonomic regulation. The excitability of preautonomic PVN neurons is controlled by the noradrenergic input from the brain stem. In this study, we determined the role of alpha(2) adrenergic receptors in the regulation of excitatory and inhibitory synaptic inputs to spinally projecting PVN neurons. Excitatory and inhibitory postsynaptic currents (EPSCs and IPSCs) were recorded using whole cell voltage-clamp techniques on PVN neurons labeled by a retrograde fluorescence tracer injected into the thoracic spinal cord of rats. Bath application of 5-20 muM clonidine, an alpha(2) receptor agonist, significantly reduced the amplitude of evoked GABAergic IPSCs in a dose-dependent manner. Also, 10 microM clonidine significantly decreased the frequency (from 2.68 +/- 0.41 to 1.22 +/- 0.40 Hz) but not the amplitude of miniature IPSCs (mIPSCs), and this effect was blocked by the alpha(2) receptor antagonist yohimbine. Furthermore, clonidine increased the paired-pulse ratio of evoked IPSCs from 1.25 +/- 0.05 to 1.61 +/- 0.08 (P < 0.05). On the other hand, clonidine had little effect on evoked glutamatergic EPSCs, mEPSCs, and the paired-pulse ratio of evoked EPSCs in most labeled cells examined. Additionally, immunofluorescence labeling revealed that the alpha(2A) receptor and GABA immunoreactivities were co-localized in close apposition to labeled PVN neurons. Collectively, these data suggest that stimulation of alpha(2) adrenergic receptors primarily attenuates GABAergic inputs to PVN output neurons to the spinal cord. The presynaptic alpha(2) receptors function as heteroreceptors to modulate synaptic GABA release and contribute to the hypothalamic regulation of sympathetic outflow.