It has been assumed that the molecular weight (MW) cut-off of a newly fabricated polysulfone capillary dialyzer (F60, Fresenius, FRG) is similar to that of the human glomerulus. We recently tested the device in vivo and found this not to be so, based on the device's ability to eliminate substances of a MW of 10,000 to 60,000 daltons. One of the reasons for this discrepancy was found to be the influence of secondary membrane formation on solute permeability. Endogenous marker substances of a defined MW (beta 2-microglobulin, myoglobin, RBP, alpha 1-microglobulin, acid alpha 1-glycoprotein, alpha 1-antitrypsin, prealbumin, and albumin were measured by laser nephelometry or radioimmune assay; sieving coefficients (SC) and protein eliminations were calculated for each low MW protein.

The data suggest that tetrahydroaldosterone is the most reliable screening test for PA. Tetrahydroaldosterone determination in combination with aldosterone-18-glucuronide and free aldosterone increases diagnostic specificity for PA. Potassium, renin, plasma aldosterone, and basal PARR are inadequate screening procedures because they are subject to high rates of false-positive and false-negative results.

Specific antisera against tetrahydroaldosterone (TH-Aldo) were raised in two white New Zealand rabbits. 3\g=a\,5\g=b\-TH-aldo-20-oxime-bovine-serum albumin complex was used as antigen. The resulting titers were 1:18 000 and 1:16 000. Except tetrahydrocortisol (THF) (0.23%) and tetrahydro\x=req-\ 18-hydroxy-11-dehydrocorticosterone (18-OH-THA) (3.2 %), all steroids and steroid metabolites gave negligible cross-reactions. Immunograms of the paper chromatograms made from the n-butanol-extract of the urines, as well as after \g=b\-glucuronidase treatment and dichlormethane extraction, were studied to further define the specificity of the antiserum. Antibody H1 (used in this study) reacted with aldosterone-18-gluc., a TH-aldosterone-glucuronide (probably the 21-glucuronide) and an unidentified less polar material. Two methods were developed: a) TH-Aldo-glucuronidc(s) estimation after ethylacetate pre-extraction as a rapid screening test of endogenous aldosterone production.b) estimation of TH-aldosterone using one chromatographic system. The results of method a) showed a significant correlation with the values obtained by technique b). Normal values (method b) were 25.88 \m=+-\16.50 \g=m\g/24h(range 9.5\p=n-\64.8 \g=m\g/24h). A significant correlation was also shown between the TH-aldo (technique b) and 18-gluc. values.TH-Aldo is the major metabolite of aldosterone isolated from human urine (Ulick 8c Liebermann 1957; Ulick 8c Vetter 1962). It is formed in the liver and excreted as glucuronide. 15-40°/o of the secreted aldosterone is excreted in the Partly presented at the

No abstract

Beta-2-microglobulin (b2M) was identified as a causative agent of amyloidosis associated with long-term hemodialysis (HD). Therefore, we examined handling of b2M during a 4-hour hemodialysis session. We compared b2M adsoprtion and diffusive/convective elimination between high-flux membranes such as polysulfone (PS; F 60®, Fresenius), polyacrylonitrile (AN 69; FiltralR, Hospal) and polyacrylonitrile (PAN, PAN 12CX2R, Asahi) and less permeable membranes such as cuprammonium rayon (CR; AM 160 HR, Asahi) and polymethylmethacrylate (PMMA; BK-1.6 UR, Toray). To calculate total elimination, arterio-venous differences of b2M were measured at 0, 5, 20, 60 and 240 minutes; dialysate concentration was analyzed to evaluate diffusive/convective transport. Differences between recovery in dialysate and total removal were regarded as amount removed by adsorption. Total elimination per 4-hour hemodialysis session and per m2 membrane surface was 154.7 ± 12.3 mg for the PS, 137.8 ± 28.4 mg for the AN 69, 179.8 ± 47.5 mg for the PAN, 130.8 ± 11.8 mg for the PMMA and 14.4 ± 16.0 mg for the CR membrane. Diffusive/convective transport was 128.0 ± 18.1 mg for PS, 54.7 ± 8.1 mg for AN 69 and 106.5 ± 20.8 mg for PAN and insignificant for PMMA and CR. Adsorption was 26.7 ± 4.3 mg for PS, 83.1 ± 29.0 mg for AN 69 and 59.8 ± 17.2 mg for PAN. Besides transmembranous transport sorption is an important mode of elimination. Weekly endogenous generation rate is about twice as high as b2M elimination

No abstract

No abstract

Although E-APT is rare, it should be considered in the interests of specific therapy for PA because aldosterone-secreting malignant ovarian tumors also have been reported.