The Brief International Cognitive Assessment in Multiple Sclerosis (BICAMS): results from the German validation study.

BACKGROUND: Recent research has convincingly shown that the ability to work mainly depends on the cognitive status in multiple sclerosis (MS). An international committee of experts recommended a brief neuropsychological battery to evaluate cognitive performance in MS. BICAMS comprises three tests, the Symbol Digit Modalities Test (SDMT), the learning trials of the California Verbal Learning Test II (CVLT-II), and the Brief Visuospatial Memory Test-Revised (BVMT-R). OBJECTIVE: To validate BICAMS on a sample of German MS patients and healthy controls (HCs). METHODS: According to the international guidelines for validation, examiner's instructions were standardized and translated into German. Due to the availability of better normative data for future applications in routine clinical care and classification of individual performance degree, the Rey Auditory Verbal Learning Test (RAVLT) (German version: Verbaler Lern- und Merkfähigkeits-Test, VLMT) was chosen instead of CVLT-II. 172 MS patients and 100 HCs entered the study. BICAMS was administered at baseline and retest (after 3-4 weeks). RESULTS: The groups did not differ in age, gender or education. Mean age of MS patients was 43.33 years (SD 11.64); 68% were female and 86.9% had relapsing-remitting MS. Patients performed significantly worse than HCs on the SDMT (p < 0.01) and on BVMT-R (p < 0.05) but not on VLMT. In addition, BICAMS was shown to be reliable over time: r = 0.71 for BVMT-R, r = 0.72 for VLMT and r = 0.85 for SDMT. SDMT z-score proved to be a good predictor for the ability to work in a full-time (p < 0.001) as well as in a part-time job (p < 0.001). VLMT z-score turned out to be a significant predictor only for the ability to work in a part-time job, while BVMT-R z-score showed no significant predictive value. CONCLUSION: In this German validation study with the VLMT, the modified BICAMS (BICAMS-M) turned out to reliably detect cognitive problems in MS patients and to monitor cognitive performance over time. SDMT revealed the best predictive value for working ability. Moreover, only the SDMT was able to predict the ability to work in a part-time or full-time job. Following these results, application of the SDMT is recommended for medical statements on working ability of MS patients.

Sporadic cases of acute autochthonous hepatitis E virus infection in Southwest Germany.

Hepatitis E infection is usually a self-limiting disease and an important cause of acute hepatitis in tropical and subtropical regions where the virus is endemic. In industrialized countries, sporadic cases of acute hepatitis E virus (HEV) infections have been described and the number of documented autochthonous infections seems to be increasing. We report three sporadic cases of autochthonous hepatitis E infections in Southwestern Germany which presented at our university hospital within two years. All cases were men who presented with acute hepatitis, icterus and elevated liver. In case 1 and case 2, liver biopsy revealed acute hepatitis, both patients were positive for anti-HEV antibodies, case 1 was also positive for HEV RNA with a viral load of 3.0 x 10(3)copies/ml in serum. In case 3, anti-HEV antibodies were detectable and HEV RNA was detected in serum (4.3 x 10(3)copies/ml) and stool (1.4 x 10(6)copies/ml). None of the patients had a recent travel history outside Germany and close contact to animals has been denied. HEV sequence analysis of two patients revealed genotype 3 with homologies to other European isolates and isolates from swine. Thus the source of infection remains unclear. Hepatitis E should be considered in differential diagnosis in patients with unexplained hepatitis and patients with acute hepatitis, whatever their age or travel history might be, should be tested for HEV.

Spectrophotometric determination of pyrrole-like substances in urine of rat and man: an assay for the evaluation of 2,5-hexanedione formed from n-hexane.

Male Wistar rats exposed to atmospheric n-hexane excreted in their urine substances which gave rise to absorption spectra like those of pyrroles after the reaction with Ehrlich's reagent. A simple spectrophotometric assay was developed to determine these "pyrrole-like substances" in urine. Their excretion kinetics were evaluated by exposing rats for 8 h to atmospheric n-hexane concentrations between 50 and 3000 ppm. The dose-response curve revealed saturation kinetics according to Michaelis-Menten, Vmax being 1.12 [delta E526.ml urine/8 h n-hexane exposure] and "Km", the atmospheric n-hexane concentration at Vmax/2, being 250 ppm. The excretion of pyrrole-like substances closely correlated with that of 2,5-hexanedione measured by Fedtke and Bolt (1987). Pyrrole-like substances were also found in the urine of a male volunteer. When exposing the person for 3 h to atmospheric n-hexane at a concentration of 146 ppm (equivalent to 55 ppm/8 h) the excreted amount was twice the background value. Due to the sensitivity of this assay it is possible to determine pyrrole-like substances in urine according to the present German MAK or US TLV conditions for n-hexane (50 ppm/8 h).

Pethidine analogues, a novel class of potent inhibitors of mitochondrial NADH: ubiquinone reductase.

Analogues of the analgetic drug pethidine were synthesized. Two N-aralkylen derivatives displayed a superior inhibitory effect on the activity of NADH:ubiquinone reductase in beef heart mitochondrial membranes. Dose-response curves revealed that the potency of these compounds is very comparable to that of the standard probe rotenone. The inhibitors were characterized by (a) their action on the reductase activity in various (eukaryotic and prokaryotic) organisms, (b) their influence on the enzyme kinetics, (c) their effects on the NADH dependent reduction of different electron acceptors, (d) their interference with the activities of other mitochondrial oxido-reductases. With regard to many of these aspects a close analogy between pethidine derivatives and rotenone was observed. A computer simulation of the steric structures of these molecules indicates that both classes of the chemically rather unrelated inhibitors may imitate very similar conformations. The potential advantages of the pethidine derivatives for the investigation of structure - function relationships within complex I of the respiratory chain is discussed.

Cloning and characterisation of nifLA regulatory mutations from Klebsiella pneumoniae.

A total of nine regulatory mutations in the nifLA operon of Klebsiella pneumoniae were cloned in the high copy-number plasmid vector pACYC184. The regulatory phenotypes of the resultant clones were then correlated with their restriction maps and their ability to synthesise nifL and nifA polypeptides in vivo. One mutation, nifL2401, was identified as a 400 bp. deletion within the nifL gene. This mutation was non-polar and caused a Nif+ phenotype which showed escape from repression by oxygen and low levels of fixed nitrogen. Identification of this deletion allows the first definitive allocation of a mutation with this phenotype to the nifL gene and provides further evidence for the role of the nifL gene product in nif-specific repression.

The use of translocatable genetic elements to construct a fine-structure map of the Klebsiella pneumoniae nitrogen fixation (nif) gene cluster.

The transposons Tn5, Tn7 and Tn10 and bacteriophage Mu have been used to derive insertion mutations in the Klebsiella pneumoniae nif gene cluster. A large number of deletion mutants have been derived by imprecise excision of insertion mutations and these deletions have been used to construct a fine-structure map of the nif cluster. Comparison of this genetic map with a physical map of the nif cluster derived by Reidel et al. (1979) showed a very good correlation between genetic and physical mapping methods. A new complementation group, designated nifU, has been identified and mapped between nifN and nifS. Polarity studies on the 14 nif cistrons now identified suggests that they are organized in at least seven transcriptional units and that all the multicistronic units are transcribed in the same direction.

Polarity of mutations induced by insertion of transposons Tn5, Tn7 and Tn10 into the nif gene cluster of Klebsiella pneumoniae.

Three new genes nifM, nifI and nifN have been mapped in the nif gene cluster of Klebsiella pneumoniae and a fourth gene nifJ has been confirmed as being a separate cistron. Polar nif mutations were obtained by transposition of Tn7 to plasmid pRD1, and of Tn5 and Tn10 to plasmid pMF100, a derivative of pRD1. Complementation analysis of the nif::Tn mutants led to the identification of at least six transcriptional units: nifB; nifA; nifJ; nifH, nifD and nifK; nifE and nifI; nifN, nifM and nifF. Biochemical and genetic evidence suggest that the three genes nifH, nifD and nifK, which are probably the structural genes for nitrogenase, belong to the same operon and are transcribed from nifH to nifK. A polypeptide with a molecular weight of approximately 120,000 is presumed to be the nifJ product.