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Biomedical subjects

G Rebentisch

Publications and source records attributed to G Rebentisch.

18 recordsLinked to original sources
PubMed2004

[Xanthinuria with xanthine lithiasis in a patient with Lesch-Nyhan syndrome under allopurinol therapy].

PURPOSE: It is the intention of this report to identify appropriate analytical tests which allow for the monitoring of allopurinol treatment of patients with Lesch-Nyhan syndrome and the prevention of uric acid or xanthine lithiasis. MATERIALS AND METHODS: A 12 year old boy with Lesch-Nyhan syndrome presented with signs of compulsive automutilation, motoric and mental retardation and cerebral palsy. Paraclinical patient showed hyperuricemia and significant hyperuricosuria. During administration of allopurinol (200 mg/d) he developed fever, an urinary tract infection and dilatation of pelviureteric junction which was suspected of being nephrolithiasis. During hospitalisation, the purine metabolism was intensively monitored. The allopurinol treatment was adjusted according to clinical and laboratory data. RESULTS: The renal scanning diagnostic showed the develepment of a functionally impaired left kidney. Later this kidney had no part in tubulo-secretorical function. It was necessary to remove surgical two renal stones. The composition of the stones was exclusively xanthine. Serum concentration and urinary excretion of xanthine and hypoxanthine were massively enlarged. The elimination of uric acid in urine was normal. But subsequently, the left kidney had to be removed despite intensive care. CONCLUSION: Lesch-Nyhan syndrome is a disorder caused by congenital absence of the enzyme hypoxanthineguanine phosphoribosyltransferase and an increase of the enzyme activity of adenine phosphoribosyltransferase. Treatment should be adjusted to patient's age and weight. An adapt treatment with allopurinol and optimal fluid intake reduce the risk of uric acid or xanthine lithiasis. Laboratory monitoring includes testings for serum concentration and urinary excretion of uric acid, xanthine and hypoxanthine. Sole a normal concentration of uric acid is not sufficient for therapy control. Assessment of the urine sediment by microscopy or infrared spectroscopy will enable early detection of uric acid or xanthine lithiasis.

Allopurinol↗
PubMed2004

[Diagnosis of systemic Candida infections. Evaluation of serology, molecular biology and D-arabinitol detection].

In order to diagnose systemic Candida infection in ICU patients, several methods were compared. In the first round, antigens and antibodies of 104 patients were investigated. Seventeen patients were infected; in nine of these patients a positive antigen was detected; elevated antibodies were detected in 11 patients. Only 42 patients were colonized. In this group, one positive antigen and six elevated antibody titres were detected. Combining these results, the sensitivity of the antigen only (58.5%) or the antibodies only (52.9%) increased to 100%. In the second round (n = 83 patients) the D-arabinitol/L-arabinitol quotient was also determined in the urine. 18.1% of the patients had elevated antibodies and 26.5% elevated D-arabinitol/L-arabinitol quotients. In the third round, PCR was also applied (n = 27 patients). Five patients had elevated D-arabinitol/L-arabinitol quotients and one of these had a positive PCR result. In conclusion, serological methods (antigen and antibody detection) should only be applied in strictly selected patients. In uncertain cases, the addition of PCR or determination of D-arabinitol/L-arabinitol might be helpful.

Antibodies, Fungal↗
PubMed1989

Comparison of methods and guaranteeing quality of analyses of urinary calculi--5th international ring test.

For five samples of our 5th international ring test for the quality control of methods of urinary calculus analysis we received 46 results from 19 countries obtained by means of ten different methods. The mean standard of quality (SQ) for all participants with quantitative methods is 2.11. Most laboratories employed X-ray diffraction (n = 21; SQ = 2.09) for quantitative calculus analysis. The mean deviation (delta x) per component from the ideal composition is fortunately low--about 0.10 molar parts for all participants, 0.06 molar parts for X-ray and infrared spectroscopy technique together. From the aspect of accuracy, the physical methods of analysis, X-ray diffraction and IR spectrophotometry, are clearly superior to all other analytical techniques.

Humans↗
PubMed1989

[Regional external quality control of the analysis of urinary calculi].

Within one year's period a model for external quality control of urolithiasis was tested. This model includes specifications concerning precision as well as accuracy derived from diagnostic and therapeutic considerations. The quality indices obtained for precision QI-P and accuracy QI-R confirm that all analytical centres of urolithiasis in the GDR are to be found under the fixed specifications, partially to a considerable extent. Thus all participants indirectly demonstrated that the state of adjustment of instrumentation and thereby the reference factors remain stable for at least one year. The system being continued the specifications of precision (ST 0%) and accuracy (D0) might even be fixed more exactly from an analytical point of view.

Germany, East↗
PubMed1988

Assessment and maintenance of the quality of urolith analyses in a comparison of methods. 4th International Ring Test to check quality.

For five test samples of the fourth International Ring Test to check the quality of methods for urinary calculus analysis, 45 findings obtained by 10 different methods were sent from 16 countries. The mean deviation of 0.11 molecular parts per component for all five samples is considerably low. The average standard SQ for all participants is 2.44. It falls off from X-ray diffraction via IR down to other quantitative methods. Advantages and disadvantages of X-ray diffraction and IR-spectroscopic analyses are discussed. Analysis of urinary calculi according to centralized, methodically uniform standards offers advantages in analytical quality.

Humans↗
PubMed1988

[Need for the differentiation of apatite and carbonate apatite].

With extensive analytical and clinical examinations it is shown that the proof of carbonate in apatite may allow no additional reference of an infection with urea-splitting bacteria. With certain analytical methods the presence of carbonate is demonstrable in each urinary calculus apatite phase. Carbonate-bearing apatite indeed is accompanied frequently with struvite, but may be occur also without an infection. Therefore, in the future it should be renounced on the differentiation of apatite and carbonate apatite in routine analyses of urinary calculi.

Apatites↗
PubMed1986

[Ensuring quality in the analyses of urinary calculi by a comparison of methods. 3d International Ring Trial].

Of 5 analysis tests of the 3rd International Ring Experiment for the control of the quality of methods of the analysis of urinary calculi 38 findings compiled according to 9 different techniques came in from 12 countries. The average deviation per component concerning all 5 analysis tests is considerably low with 0.10 mol proportions. The average quality measure SQ concerning all participants is approximately 2.00; it deteriorates from the X-ray diffraction method over the IR-technique to the other quantitative methods used. Advantages and disadvantages of the X-ray diffraction and IR-spectroscopic analysis are discussed. A methodically homogeneous and centralized performed analysis of urinary calculi shows advantages in the quality of the analyses.

Apatites↗
PubMed1984

International ring test to check the quality of urolith analyses.

In an international ring test, five mixtures of stone substances were analyzed with different methods in 29 selected stone analysis laboratories in 13 countries. Evaluation revealed very good analysis qualities especially for X-ray diffractometric and infrared techniques. The analytical skills of the investigators are confirmed by a mean standard of quality of 1.69 for all qualitative results determined. It would be possible to improve the diagnosis of urolithiasis by standardizing and centralizing stone analysis.

Calcium Phosphates↗
PubMed1983

[Criteria of usefulness for the standardized x-ray diffractometric urinary calculus analysis. Improvement in the quality of urinary calculus analysis by the establishment of uniform methodological assumptions in urinary calculus analysis laboratories. 1].

Urolith analysis by X-ray diffraction is centralized and standardized in the GDR. By setting up uniform methodological conditions the quality of analytical results can be markedly improved. The resulting analytical criteria of usefulness - precision, detection limits and correctness - meet the requirements of diagnostic reliability and guarantee therapeutic relevance.

Germany, East↗
PubMed1983

[Evidence of improved quality of urinary calculus analysis using results of 7 surveys with external quality controls. Improvement in the quality of urinary calculus analysis by establishment of uniform methodological assumptions in urinary calculus analysis laboratories. 2].

Seven quality control surveys confirmed the usefulness of standardized urolith analysis by X-ray diffraction. A method is suggested for tabulating the results of the surveys, which permits qualitative comparison of participating analysis centres. Quality improved considerably after the introduction of the standardized instructions for analysis. The results of the survey with international participants clearly demonstrated the superiority of X-ray diffractometric urolith analysis over polarization microscopical, infrared spectroscopic, differential thermoanalytical and wet chemical analytical techniques.

Humans↗
PubMed1983

[Suggestion for the evaluation of roentgen diffractometric urinary calculus analysis results based on the 5th and 6th East German trial].

The evaluation system suggested allows the results of urinary-calculi analysis centres to be compared after estimating the calculus stages present, the distinction between primary and secondary components and the deviation from normal composition. Afterwards the quality of the results of analysis of urinary calculi improved using the standard method.

Humans↗
PubMed1982

[The cell number in spontaneous uncentrifuged urine].

The leucocytes and erythrocytes in spontaneous urines were determined in the counting chamber at native and experimentally reduced pH values after standing for various periods. The pH value remained constant for up 6 h, whereby the disintegration of cells increases with rising pH values. The investigations do not rule out a circadian rhythm of cell excretion referring to the quantity of cells/time. Depending on the absolute number of cells the methodic variation coefficient lies between 4 and 25%.

Adult↗