Regulation of murine arthritis by systemic,spinal, and intra-articular adrenoceptors

BackgroundThe regulation of the immune system by the sympathetic nervous system is allowing the design of novel treatments for inflammatory disorders such as arthritis. In this study, we have analyzed the effects of α- and β-adrenoceptor agonists injected subcutaneously, intrathecally, or intra-articularly in zymosan-induced arthritis.MethodsMurine arthritis was induced by intra-articular (knee joint) injection of zymosan. α1 (phenylephrine), α2 (clonidine), β1 (dobutamine), or β2 (salbutamol)-adrenoceptor agonists were injected subcutaneously (sc), intrathecally (it), or intra-articularly (ia) to activate peripheral, spinal, or intra-articular adrenoceptors and to study their effects on articular edema formation and neutrophil migration into the synovial cavity.ResultsTreatments with phenylephrine did not affect the edema formation, but it increased neutrophil migration when injected subcutaneously (155.3%) or intra-articularly (187.7%). Treatments with clonidine inhibited neutrophil migration (59.9% sc, 68.7% it, 42.8% ia) regardless of the route of administration, but it inhibited edema formation only when injected intrathecally (66.7%) or intra-articularly (36%) but not subcutaneously. Treatments with dobutamine inhibited both edema (42.0% sc, 69.5% it, 61.6% ia) and neutrophil migration (28.4% sc, 70.3% it, 82.4% ia) in a concentration dependent manner. Likewise, all the treatments with salbutamol also inhibited edema formation (89.9% sc, 62.4% it, 69.8% ia) and neutrophil migration (76.6% sc, 39.1% it, 71.7% ia).ConclusionWhereas the β-adrenoceptor agonists induced anti-inflammatory effects regardless of their route of administration, α1- and α2-adrenoceptor agonists induced either pro- and anti-inflammatory effects, respectively.     

Inferior alveolar nerve lateralization and implant placement in atrophic posterior mandible

The aims of this article were to describe the surgical technique of the inferior alveolar nerve lateralization followed by implant installation by means of a clinical report and also to discuss the importance of an adequate surgical and prosthetic planning for atrophic posterior mandible rehabilitation.     

Vertical ridge augmentation of the atrophic posterior mandible with a 2-stage inlay technique: a case report

The use of a 2-stage inlay technique in atrophic posterior mandibles with more than 10-mm thickness and less than 5-mm height above the inferior alveolar nerve is described. The first surgical procedure was a basic corticotomy of the buccal and lingual bone. One month later, a complete inlay procedure was performed. Computed tomography and conventional radiography showed a mean vertical bone gain of 11.5 mm. This 2-stage inlay technique avoids the use of chisels to complete bone osteotomy and reduces postsurgical nerve disturbances in atrophic posterior mandibles. This technique reduces intraprocedure and postoperative patient discomfort.     

Hypoxaemic rescue therapies in acute respiratory distress syndrome: Why,when, what and which one?

Acute respiratory distress syndrome (ARDS) is an inflammatory condition of the lungs which can result in refractory and life-threatening hypoxaemic respiratory failure. The risk factors for the development of ARDS are many but include trauma, multiple blood transfusions, burns and major surgery, therefore this condition is not uncommon in the severely injured patient. When ARDS is severe, high-inspired oxygen concentrations are frequently required to minimise hypoxaemia. In these situations clinicians commonly utilise interventions termed ‘hypoxaemic rescue therapies’ in an attempt to improve oxygenation, as without these, conventional mechanical ventilation can be associated with high mortality. However, their lack of efficacy on mortality when used prophylactically in generalised ARDS cohorts has resulted in their use being confined to clinical trials and the subset of ARDS patients with refractory hypoxaemia.     

Exercise Studies in Patients With Rotary Blood Pumps: Cause,Effects, and Implications for Starling‐Like Control of Changes in Pump Flow

This multicenter study examines in detail the spontaneous increase in pump flow at fixed speed that occurs in exercise. Eight patients implanted with the VentrAssist rotary blood pump were subjected to maximal and submaximal cycle ergometry studies, the latter being completed with patients supine and monitored with right heart catheter and echocardiography. Maximal exercise studies conducted in each patient at three different pump speeds on separate days established initially the magnitude and consistency of increases in pump flow that correlated well with changes in heart rate. However, there was considerable variation, coefficients of variation for mean heart rate and pump flow being 47.9 and 49.3%, respectively. Secondly, these studies indicated that increasing pump flows caused significant improvements in maximal exercise capacity. An increase of 2.1 L/min (35%) in maximum blood flow caused 12 W (16%) further increase in achievable work, 1.26 (9.3%) mL/kg/min in maximal oxygen uptake, and 2.3 (23%) mL/kg/min in anaerobic threshold. Mean increases in lactate were 0.85 mm (24%), but mean B‐type natiuretic peptide fell by 126 mm , (?78%). From submaximal supine exercise studies, multiple linear regression of pump flow on factors thought to underlie the spontaneous increase in pump flow indicated that it was associated with increases in heart rate (P = 0.039), pressure gradient across the left ventricle (P = 0.032), and right atrial pressure (P = 0.003). These changes have implications for the recently reported Starling‐like controller for pump flow based on pump pulsatility values, which emulates the Starling curve relating pump output to left ventricular preload. Unmodified, the controller would not permit the full benefits of this effect to be afforded to patients implanted with rotary blood pumps. A modification to the pump control algorithm is proposed to eliminate this problem