Chemiluminescent immunoassay (CLIA) for urinary albumin.

A simple chemiluminescent immunoassay (CLIA) for urinary albumin has been developed based on the use of a chemiluminescent acridinium ester-labelled human albumin and a commercially available antiserum. It includes two incubation steps and a second polyethylene glycol-assisted antibody separation. The sensitivity of detection is 0.016 mg/l, the assay working range is 0.1-5 mg/l, and the inter-assay CVs are less than or equal to 15%. Using 10- and 50-fold sample dilutions in assay buffer, a wide working range (1-250 mg/l) is obtained covering normal and pathological conditions. Timed overnight urine samples (bed rest conditions) were collected on three consecutive days for each patient. Albumin excretion rate (AER) was 4.7 +/- 2.7 micrograms/min (mean +/- SD), range 1-15.9 micrograms/min in 36 healthy subjects (17 male, 19 female, ages 4-56 years), with day-to-day variations of 28.5 +/- 20% (mean +/- SD), range 3.3-76.1%. The use of an acridinium ester as a chemiluminescent (CL) label overcomes the disadvantages of short shelf-life and health and safety hazards associated with radioisotopes. Results compare favourably with those obtained using a commercially available RIA kit.

Effect of surfactants on the intensity of chemiluminescence emission from acridinium ester labelled proteins.

In order to establish optimum conditions for the chemiluminescent (CL) reaction of two acridinium ester labelled proteins (human albumin and rabbit anti-human albumin IgG), we investigated the effects of the following factors known to influence the CL emission: pH, presence of proteins, relative concentrations of components of CL reaction and presence of surfactants. Under optimal conditions of pH and hydrogen peroxide concentration, hexadecyl trimethyl ammonium chloride (CTAC) increased the intensity of the CL reaction of the acridinium ester labelled albumin by 42-fold. Triton X-100, Tween-20, 23 lauryl ether (Brij 35) and sodium dodecyl sulphate (SDS) exerted a much smaller effect. In the case of the acridinium ester labelled antibody, the greatest increase was obtained with Triton X-100 (15-fold) followed by CTAC, Brij 35 and Tween 20 (SDS decreased the emission intensity).

[Hepatic hemangioendothelioma with interauricular communication]. / Hemangioendotelioma hepático a communicación interauricular.

A case of hepatic hemangioendothelioma in an infant of 2 1/2 months of age is presented. This case showed clinical features of this malformation: cardiac failure, severe hepatomegaly and cutaneous hemangiomata. The cardiac failure was complicated by the presence of an atrial septal defect. This symptomatology persisted after the surgical closure of the cardiac defect. The control of cardiac failure was only possible by using high doses of metil-prednisolone (2 mg/kg/day). The scheme of management in the treatment with steroids was revised, and the good results obtained in this case and in other series recorded. The use of surgical techniques (hepatic artery ligation or lobectomy), and radiotherapy, is relegated to a secondary plane by these findings.