The prevalence of peripheral arterial disease and medial arterial calcification in patients with chronic renal failure: requirements for diagnostics

BACKGROUND: Knowledge of the prevalence of peripheral arterial disease (PAD) in patients with chronic renal failure (CRF) is limited because of a lack of uniformity in disease definition and recognition. Furthermore, little is known of the prevalence of medial arterial calcification (MAC) in patients with CRF. Our goal is to study the prevalence of PAD and MAC defined by ankle brachial index (ABI) or toe brachial index (TBI) measurements in a Finnish population of patients with CRF consisting of predialysis and dialysis patients, as well as renal transplant recipients. METHODS: We examined 136 patients with CRF and 59 control subjects. Fifty-nine of the patients with CRF had moderate to severe predialysis CRF, 36 patients were on dialysis treatment, and 41 were renal transplant recipients. Mean age of patients was 51.9 +/- 11.5 years, and 39 patients (29%) had diabetes. ABI and TBI were measured by means of photoplethysmography. The definition of PAD required an ABI value of 0.90 or less, a TBI value of 0.60 or less, or a previous positive lower-extremity angiogram result. ABI values of 1.3 or greater or incompressible arteries at ankle level indicated MAC. The presence of claudication was determined by an interview. RESULTS: Prevalences of PAD on this study were 22.0% in patients with predialysis CRF, 30.6% in patients on dialysis treatment, 14.6% in renal transplant recipients, and 1.7% in the control group (P = 0.001). Prevalences of MAC were 23.7%, 41.7%, 23.1%, and 3.4% (P < 0.001), respectively. Only 9 patients had claudication, and 6 of those patients had PAD. CONCLUSION: Both asymptomatic PAD and MAC are common in patients with CRF. Therefore, we recommend the use of both ABI and TBI measurements in the evaluation of PAD in patients with CRF.     

Shoulder instability: impact of glenohumeral arthrotomography on treatment

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.     

ATP release from human airway epithelial cells studied using a capillary cell culture system

Epithelial release of adenosine triphosphate (ATP), an important autocrine and paracrine signalling molecule, is acutely mechanosensitive and therefore difficult to study. We describe here a novel preparation that minimizes mechanical and metabolic perturbations, and use it to examine ATP secretion by epithelial cells. The Calu-3 cell line derived from human airway sub-mucosal glands was cultured in a hollow fibre bioreactor on porous capillaries that were perfused by a re-circulating medium pump. Cells became polarized and cultures were stable for > 5 months, as evidenced by microscopy and lactate production (≈250 μg (10⁸ cells)⁻¹ day⁻¹). Elevating apical flow rate 5-fold increased ATP secretion from ≈200 to 6618 fmol min⁻¹. Reducing apical osmolarity by 25–43 % also increased ATP secretion, which then declined spontaneously to a plateau rate that persisted as long as hypotonic perfusion was maintained. Release deactivated rapidly after shear and osmotic stresses were terminated, and was not associated with detectable cell lysis. Lowering apical [Ca²⁺] to increase connexin hemichannel permeability also stimulated ATP release and increased secretion during both hyposmotic and shear stress; however, the connexin 43 blocker flufenamic acid inhibited shear-induced ATP release only in low-Ca²⁺ solution, and therefore another secretory pathway may operate with physiological (i.e. m m ) calcium. Regardless of the mechanism, the present results quantify ATP responses to mechanical and osmotic stimuli and demonstrate the usefulness of capillary cultures for studying epithelial secretion.