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Thirtheen male patients with chronic renal failure undergoing regular dialysis treatment (2 X 8-10 hours/week) were treated with gonadotropins (HCG, Primogonyl) primarily 2 X 2,000 IU/week and later 2,000 IU/week. Before HCG administration and during 4-months HCG-therapy testosterone, dihydrotestosterone, Androstandiol, LH and FSH levels were determined by RIA-methods in 7-14 days intervals. Before HCG-application plasma testosterone levels were low and did not increase in the course of regular dialysis treatment. Derivates from testosterone like dihydrotestosterone and Androstandiol were elevated in plasma, presumbably because of accumulation in renal failure. LH-levels were slightly elevated on the average. FSH-levels showed a high individual variation but also seemed to be elevated on the average. HCG stimulation by exogenous HCG administration for short time resulted in a insufficient rise of testosterone levels as compared to normals. During prolonged HCG administration plasma testosterone levels increased to normal but dropped immediatly after cessation of therapy or reduction to less than 2,000 IU HCG twice/week. Body weight, plasma proteins, haematocrite and fertility did not improve significantly. These results indicate that in chronic renal failure androgen synthesis by testicular tissue is seriously impaired and does not improve under usual dialysis treatment. Feedback regulation of testosterone levels by increase of LH levels seems not to be sufficient although pituitary response is found to be normal. This may be explained by elevated levels of testosterone derivates which exert negative feedback effects.

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Modern steel and pressure vessel construction requires heavy plates with tailored properties. In addition to satisfying quality standards, delivery on schedule is an important requirement for building projects. To show how these demands on actual deployment of plates are realized, this paper discusses methods for optimum production planning and production control where the focus is upon improving the flow of work, thus gradually eliminating unevenness across the system to realize the demands. Owing to the complexity of the heavy plate production process, computer‐based modelling of material flow processes is presented as a suitable tool. In addition, important aspects of quality assurance and quality control during the production of high‐performance plates are summarized. The quality characteristics of the plates are suitable surface quality, flatness, dimensional accuracy und mechanical and technological properties. How these features are controlled during the production of heavy plates is presented systematically.

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