Although the DN patients have inappropriately low EPO levels for the severity of their anaemia, they can mount an appropriate EPO response to moderate hypoxia. The mechanism underlying the EPO-deficient anaemia present in some diabetic patients remains unclear.

SUMMARY.A number of cardiac interventional procedures are available for the treatment of angina, including percutaneous transluminal coronary angioplasty (PTCA), stent insertion and rotational atherectomy (RA). Variable degrees of myocardial cell injury during PTCA and stent insertion have been observed, based on rises in creatine kinase MB isoenzyme (CK-MB) and cardiac troponin T (cTnT) 6±24 h post-procedure. As there are many variations in technique within each procedure it would be helpful to be able to determine objectively the degree of myocardial damage in order to optimize technique. We measured CK-MB, cTnT and cardiac troponin I (cTnI) to ascertain which is the most sensitive marker for minor myocardial damage in this setting. Blood samples were taken both before and 6, 14 and 24 h after the procedure in 109 patients (77 men) with angina, 42 of whom had unstable angina. Of the 109 patients, 86 had a stent inserted (21 as a primary stent), nine had PTCA, eight had RA and six intracoronary brachytherapy. Using the manufacturers' recommended cut-offs ± CK-MB 4 g/L, cTnI and cTnT 0´1 g/L ± ®ve patients were excluded from further analysis as all three markers were raised pre-procedure. Post procedure all three markers were in agreement for 68 patients (44 all normal, 24 all raised). Overall, CK-MB was raised in 28 patients, cTnT in 38 and cTnI in 58. In 19 patients CK-MB and cTnT were normal, but cTnI was raised (15 between 0´11 and 0´30 g/L). cTnI was the most sensitive indicator of minor myocardial damage, but at the recommended cut-off of 0´1 g/L may be overly sensitive. We await the results of our follow-up study to determine the clinical implications of these small rises in cTnI.

SUMMARY. Six erythropoietin (EPa) measurement kits from different manufacturers were evaluated for ease of use and performance. Reference values were compared from patient samples with normal and abnormal circulating serum EPa. The kits evaluated were EPO-Trac RIA, EPORIA, DSL RIA, EPa EIA, IBL ELISA and Medac ELISA (see below for manufacturers' details).The radioimmunoassay (RIA) methods were simple to perform with little preliminary preparation of reagents but the non-isotopic methods were of varying degrees of complexity. Imprecision data showed that performance of the RIA methods was acceptable across the range 4D-150 mUjmL [within-assay coefficient of variation (CY)=2-5%, between-assay CY=3-7%] but poor (CY> 10%) at the lower end of the range (lD-15mUjmL). The IBL enzyme-linked immunosorbent assay (ELISA) kit showed good precision across the range ID-54mUjmL (withinassay CY=5-7%, between-assay CY=8-12%). The performance of the EPa enzyme immunoassay (EIA) and Medac ELISA were acceptable although precision was poor at the lower end of the range ( < 10 m UjmL; within-assay CY 10% and 17% and between-assay CY 13% and 18%, respectively).The ELISA and EIA methods had lower limits of detection (0·4--0'8 mUjmL) than the RIA methods (2·3-3·6mUjmL).Analysis of serum EPa measurement variation between methods showed evidence of significant negative bias with DSL RIA and Medac ELISA when compared with EPO-Trac RIA. Conversely, EPORIA showed significant positive bias and the two remaining methods, EPa EIA and IBL ELISA, showed no evidence of systematic bias when compared with EPO-Trac RIA. Patients with normal circulating concentration of serum EPa gave values that were within the reference range of the kits.

1. Cyclosporin A absorption was examined after the instillation of approximately 2 mg/kg into four segments (mean length 15 cm) of rat small bowel, isolated in situ in fed Wistar female rats: SI (duodenum and proximal jejunum distal to the common bile duct); SII (distal jejunum); SIII (proximal ileum) and SIV (distal ileum). 2. Cyclosporin A concentrations in whole blood were assayed by an enzyme-mediated immunoassay for up to 4 h in samples drawn from the femoral vein and used to determine the following pharmacokinetic parameters: the area under the blood cyclosporin A concentration versus time curve (AUC, 0-4 h), the maximum blood concentration of cyclosporin A (Cmax.), the time to reach Cmax. (tmax.), the absorption half-life (t1/2a), the elimination half-life (t1/2 lambda), and the mean residence time (MRT). 3. Cyclosporin A absorption in SI (AUC, 991 micrograms l-1 h) was nearly double that in more distal segments and decreased progressively (SII, 533 micrograms l-1 h; SIII, 470 micrograms l-1 h; SIV, 419 micrograms l-1 h). There were corresponding differences in Cmax.: 327 micrograms/l in SI and 201 micrograms/l, 169 micrograms/l and 151 micrograms/l in SII, SIII and SIV, respectively. Tmax. was shorter in SIV (0.9 h) than in other segments (1.3-1.5 h), but there were no significant differences between the segments for t1/2a, t1/2 lambda or MRT. 4. In the presence of continuous bile flow (diverted via a cannula for SIV), cyclosporin A absorption significantly increased by 23% in SI and by 50% in SIV, but the differential between absorption in SI and SIV was maintained.(ABSTRACT TRUNCATED AT 250 WORDS)