[Isolation, structure elucidation and synthesis of a hexapeptide from the hemodialysate of uremic patients]. / Isolierung, Strukturaufklrung und Synthese eines Hexapeptids aus dem Hämodialysat urämischer Patienten.

Lyophilised hemodialysates of uremic patients were fractionated on Sephadex G-15 for investigation of potential uremic toxins. One of the oligopeptides found in the fraction of postulated toxins was purified to homogeneity by gel, reversed-phase and adsorption chromatography and by high-performance liquid chromatography. Dansyl Edman degradation revealed the sequence Ala-Phe-Phe-Gly-Glu, which was synthesized by the solid-phase method. The comparison of synthetic and natural hexapeptide by chromatographic methods, mass spectrometry, 1H- and 13C-nuclear magnetic resonance proved the correct sequence. The peptide showed only weak activity in immunological test systems and in the lymphocyte proliferation test.

[Bacteriological examinations using the invagination catheter]. / Bakteriologische Untersuchungen mit dem Invaginationskatheter.

Quantitative and qualitative bacteriological studies have been performed on bladder urines taken by two different technics. Bladder urine was first obtained by suprapubic bladder aspiration. Immediately after the puncture another sample of bladder urine was obtained by the "invagination catheter" (only usable in women) transurethrally. In 80 consecutive parallel studies no differences were found in the bacterial counts, and only one difference were found in bacterial type. From the diagnostic point of view, therefore, the two methods were found to be equivalent. In another series of 52 patients catheterization by the invagination catheter was repeated at least 6 hours later without urination in the meantime. The bacteriologic results in the two corresponding specimens were exactly the same in all patients. Contrary to other transurethral methods, no introduction of bacterial agents into the bladder appears to occur with this method.

[Quantitative and qualitative bacteriological studies on urine specimens obtained by suprapubic needle aspiration and on midstream-voided samples]. / Quantitative und qualitative bakteriologische Untersuchungen an gleichzeitig gewonnenen Blasenpunktat- und Mittelstrahl-Urinen.

In 398 patients with suspected urinary tract infection, quantitative and qualitative bacteriological studies were conducted in urine samples obtained by suprapubic needle aspiration of the bladder (BPU) and in midstream-voided specimens (MSU) collected immediately following the aspirations. In MSU, bacteria were found in 96.5% of all cases and in BPU in only 38.2%. Of the infected MSU, 63.3% showed mixed infections, while mixed cultures were found in only 11.2% of infected BPU. In 80% of the investigated patients, the MSU contained at least one more type of bacteria than the BPU, thus indicating urethral contamination. Of the patients with bladder bacteriuria, only 74% had bacterial counts of 10(5)/ml or more in the midstream-voided urine. Accordingly, 26% of the urinary tract infections diagnosed by bladder aspiration would not have been recognized on the basis of a single bacterial count in the midstream-voided urine. On the other hand, about 4% of patients with bacterial counts of 10(5)/ml or more in the MSU had a sterile bladder aspirate. In 72.4% of the infected BPU, E. coli was found, followed in frequency by Enterococcus (14.5%). In the infected MSU, however, Enterococcus was more frequent than C. coli (65.6% and 61.7% respectively). Thus, E. coli appears to be the most important etiological species in infections of the bladder and the kidneys, while Enterococcus seems to be the most frequent contaminant during urethral passage. The most frequent bacterial combination in mixed cultures in both BPU and MSU was that of E. coli and Enterococcus.