Role of excretory graft function for erythropoietin formation after renal transplantation

To examine the role of renal excretory function for erythropoietin (EPO) formation we have determined the kinetics of plasma immunoreactive EPO (irEPO) in patients with end-stage renal disease undergoing renal allotransplantation (RTX). In 13 patients with immediate excretory graft function (imGF) and stable haemoglobin (Hb) concentrations (median Hb 9.5 g dl-1 and median irEPO 18 mU ml-1 before RTX) irEPO increased significantly on day 4 after RTX to a median value of 29 mU ml-1 and 2 days later reached a plateau of 34.4 +/- 3.3 mU ml-1 (mean +/- SD of daily median values during days 6-20). In patients with imGF having acute blood loss and subsequently receiving transfusions, irEPO responded in an inverse fashion to changes in Hb concentrations. In 12 patients with delayed graft function (dGF) (median Hb 8.8 g dl-1 and median irEPO 15 mU ml-1 before RTX) irEPO levels during the period of excretory failure remained either unchanged or displayed marked variations with peak values greatly exceeding those of patients with imGF. These variations were not related to changes in Hb concentrations and irEPO levels did not change following alterations in Hb concentrations. Upon recovery of excretory function irEPO approached the values found in patients with imGF. The results suggest that an intact excretory renal function is not a prerequisite for the capability to produce EPO, but correlates with the oxygen-dependent regulation of EPO formation.     

A chromogenic assay for activated protein C resistance

Summary. Resistance to activated protein C (APC) diagnosed on the basis of prolongation of clotting time in an activated partial thromboplastin time (aPTT) assay is now considered a major cause of inherited thrombophilia. The majority of patients with APC resistance carry a factor V molecule with a point mutation at one APC cleavage site (Arg506Gln) which prevents the optimal inactivation of activated factor V by APC. To overcome the limitations of aPTT-based assays in the diagnosis of APC resistance, we have developed a chromogenic assay which is based on the capacity of APC to limit the generation of factor Xa by inactivating factor Villa in plasma. The ratio of the factor Xa amidolytic activity in a sample without APC to its factor Xa activity with the addition of APC reflects the response of the plasma coagulation system to APC. The normal range in 44 healthy individuals was 1.62-2.06. APC response ratios as measured by the chromogenic assay correlated with ratios measured by the aPTT assay and were below the normal range in 23.24 individuals with Arg506Gln mutant factor V from three different families with familial thrombosis and from 11 unrelated asymptomatic individuals. In reconstitu-tion experiments, purified factor V corrected the decreased APC response in plasma samples from patients with the Arg506Gln mutation as well as with factor V deficiency, and increased the APC response in normal plasma, whereas the addition of activated factor V had no enhancing effect.     

Hepatitis B and C genotyping: methodologies and implications for patient management

Abstract   The spontaneous tendency of the hepatitis B virus (HBV) and hepatitis C virus (HCV) to mutate has led in both cases to the emergence of distinct viral genotypes with uneven geographic distributions. Numerous studies point to differential impacts of these genotypes on the course of chronic liver disease and response to treatment with currently approved drugs. HCV genotype plays a pivotal role in determining an individual's response to treatment. Evidence is also accumulating that HBV genotypes influence HBeAg seroconversion rates, the natural history and severity of chronic HBV liver disease, and the development of antiviral drug-resistance and precore/core promoter mutational patterns—all of which have an impact on disease prognosis and patient management. An overview of HBV and HCV genotypes, diagnostic methodologies for their determination, and the clinical relevance of genotypes for patient management is presented.     

Percutaneous arterial cannulation in children

For percutaneous arterial monitoring in children, the Medicut (polypropylene) is an appropriate choice of cannula. Morbidity associated with its use is low. We studied blood flow and clinical signs relating to 70 arterial cannulations in 62 patients. In the few patients exhibiting flow disturbances either whilst the cannula was in situ or following decannulation, we observed no associated clinical signs of vascular insufficiency of the forearm, wrist or digits. Also, most patients showed normal, antegrade blood flow past the cannula in situ and following decannulation. Eight patients showed retrograde flow which, in six cases, spontaneously reverted to normal whilst the child was still in hospital. The results of this study increased our confidence in the appropriateness, safety and ease of use of these polypropylene cannulae in children where peripheral arterial vessel diameters are small.     

Temazepam as premedication in elderly patients

One hundred and forty-five men were randomly allocated on a double-blind basis to receive either temazepam 20 mg, diazepam 10 mg or placebo as premedication. Temazepam produced more sedation than either diazepam or placebo. Postoperative recovery was assessed by a simple visuo-motor co-ordination test and was best in the placebo group. Two hours into recovery, temazepam patients could almost match their baseline performance whereas the performance of the diazepam patients was still significantly worse than pre-operatively. Temazepam is suggested as a suitable premedicant for elderly patients undergoing minor surgery.