[Infection-induced urinary stones]. / Infektinduzierte Harnsteine.

Infection stones make up approximately 15% of urinary stone diseases and are thus an important group. These stones are composed of struvite and/or carbonate apatite. The basic precondition for the formation of infection stones is a urease-positive urinary tract infection. Urease is necessary to split urea into ammonia and CO(2). As a result, ammonia ions can form and at the same time alkaline urine develops, both being preconditions for the formation of struvite and carbonate apatite crystals. When these crystals are deposited infection stones form. Pathogenetically, various risk factors play a role: urinary obstruction, neurogenic bladder, dRTA, and MSK. If these infections are not treated and the stones are not removed, the kidney will be damaged. Modern methods are available for stone removal, e.g., ESWL and/or instrumental urinary stone removal. Here, especially less invasive methods are preferable. Any treatment must be adjusted to the patient individually. Patients should be examined frequently for recurrent urinary tract infections and stone recurrences, and new infections must be resolutely treated. Good therapy and prophylaxis are possible with present-day treatment modalities.

Urinary infection stones.

Infection stones make up approximately 15% of urinary stone diseases and are thus an important group. These stones are composed of struvite and/or carbonate apatite. The basic precondition for the formation of infection stones is a urease positive urinary tract infection. Urease is necessary to split urea to ammonia and CO(2). As a result, ammonia ions can form and at the same time alkaline urine develops, both being preconditions for the formation of struvite and carbonate apatite crystals. When these crystals deposit themselves infection stones form. If these infections are not treated and the stones are not removed, the kidney will be damaged. For stone removal modern methods are available, e.g. ESWL and/or instrumental urinary stone removal. Here especially less invasive methods are preferable. Any treatment must be adjusted to the patient individually. Patients should be examined frequently for recurrent urinary tract infections and stone recurrences and, newly arising infections must be resolutely treated. Good therapy and prophylaxis are possible with present-day treatment modalities.

Schistosomiasis: a critical review.

Precise data on epidemiology, morbidity, post-treatment resolution, reinfection, and resurgence of schistosomiasis could be helpful in establishing purposeful treatment plans for the disease in endemic populations. Here we give a concise overview of recent publications on bilharziasis. A main emphasis is placed on studies on the prevalence of schistosomiasis, partly including long term surveillance of morbidity following treatment with praziquantel. As genito-urinary schistosomiasis may be a risk factor for the spread of HIV, the involvement of the reproductive tract has become another focus in research on the disease. A novel diagnostic tool, eosinophil cationic protein (ECP), is proposed to correlate with the degree of inflammation of the genito-urinary tract.

Excretion of tamm-horsfall protein in patients with uric acid stones.

The cause of reduced Tamm-Horsfall protein excretion in patients suffering from uric acid diathesis is still unknown. Our investigation was conducted based on the hypothesis that the solubility of uric acid is increased by Tamm-Horsfall protein and that an increased uric acid content in the urine might cause a decrease in Tamm-Horsfall protein. In 20 patients with uric calculi the excretion of Tamm-Horsfall protein, uric acid, calcium, and citrate was measured. 65% of the patients had pure uric acid stones (group I) and 35% showed mixed stones with at least 30% of uric acid (group II). Reduced Tamm-Horsfall protein excretion was found in 63% of the patients of group I and in 43% of the patients of group II. The excretion of Tamm-Horsfall protein was significantly reduced in pure uric acid stone formers compared to normal subjects (p < 0. 0001). The excretion of uric acid was elevated in 61% of the patients of group I and in 86% of the patients of group II. There was no significant correlation between Tamm-Horsfall protein excretion and uric acid excretion (r = 0.2139). Calcium excretion was elevated in 57% of the patients with mixed stones. The excretion of citrate was reduced in almost all of the patients of groups I and II. Our results do not support the hypothesis that an increased content of uric acid in the urine causes a decrease in Tamm-Horsfall protein. In our opinion the lower excretion of Tamm-Horsfall protein in some of the stone patients might be caused by damage in the distal tubular epithelium. Moreover, it has to be supposed that there are defects both in the distal and the proximal tubule in patients prone to develop uric acid calculi.

[Methodologic comparison of the analysis of urinary calculi. Roentgen diffractometry, polarization microscopy and microscopic-microchemical component analysis]. / Methodischer Vergleich von Harnsteinanalysen. Röntgendiffraktometrie, Polarisationsmikroskopie und mikroskopisch-mikrochemische Komponentenanalyse.

Not only instrumental, apparative or operative stone extraction is necessary for patients with urolithiasis (particularly those with recurrent urolithiasis); preventive treatment is also called for, and for this exact analysis of the composition of the stones is essential. The procedures currently accepted as standard for stone analysis are: X-ray diffraction, infrared spectroscopy, polarisation microscopy and the complicated chemico-quantitative analyses performed in some institutes. Recently a new, so-called microscopic-microchemical, analysis of stone components has been presented (the Harzalith). To test the value of this procedure as compared to e.g. X-ray diffraction or polarization microscopy, a comparative study was carried out in our department. Thirty different urolith compositions (calculi with one and with more components) were analysed qualitatively and quantitatively by three methods. No qualitative difference was found between X-ray diffraction and polarization microscopy; however, there was a difference from the Harzalith method, and with increasing number of components there was hardly any correspondence with the other methods. Only 10% of the calculi with three or four components could be analysed correctly. Often, too many components were determined by the new method. The test material was analysed by three laboratory assistants working independently of each other.