Frequency-modulated simultaneous Atomic Absorption Spectrometry (FremsAAS): Determination of As, Se and Sb.

The evaluation of accuracy and efficiency of the frequency-modulated simultaneous Atomic Absorption Spectrometry (FremsAAS) has been extended to an arrangement with EDL as light sources. Fundamental calibrations have been worked out for As, Se and Sb using a graphite furnace as well as hydride generation in combination with a heated quartz tube as atomization unit. The characteristic data are in good agreement with results obtained by conventional single-channel AAS instruments.

A mathematical equation to differentiate overload proteinuria from tubulo-interstitial involvement in glomerular diseases.

Determination of marker proteins like albumin and alpha 1-microglobulin allows to differentiate various types of proteinuria in kidney diseases. In the present communication we calculate the degree of tubulointerstitial involvement by quantitation of the tubular marker alpha 1-microglobulin in urine in relation to albuminuria. A mathematical relation between minimal tubular proteinuria with the degree of albumin excretion was observed.

Diagnostic strategies in urinalysis.

The traditional methods in urinalysis (visual microscopy, qualitative test strip screening) were compared with automated microscopy (UA-1000, TOA-medicals, Japan) and quantitative single protein analysis in 562 fresh morning urine samples. Albumin served as "glomerular" and alpha 1-microglobulin as "tubular" markers measured by turbidimetry. The test strip delivered at least one positive result in 60% of the urine for blood (21%), leukocytes (27%), or protein (34%).

A new strategy for characterizing proteinuria and haematuria from a single pattern of defined proteins in urine.

Prerenal, glomerular, tubulointerstitial and postrenal proteinurias and haematurias are usually differentiated by a number of non-invasive and invasive diagnostic procedures. We have applied a new analytical strategy based on the observation that different urine protein patterns are excreted in normal, prerenal, renal and postrenal proteinurias and haematurias. When analysed by turbidimetric procedures urine albumin, IgG, alpha 1-microglobulin and alpha 2-macroglobulin can be used as marker proteins to characterize the degree of glomerular permeability, tubular protein reabsorption and postrenal bleeding respectively.

[Prognosis in primary glomerulonephritis].

Appraisal of the long-term prognosis of primary glomerulonephritis at the time of diagnosis, i.e. when there are no longitudinal observations, is based on the constellation of clinical findings as well as on the morphological changes in glomeruli and interstitial renal tissue which can be detected in histological examinations of biopsy specimens.