Cerebral oligemia and iron influence in cerebral structures--element of morbus parkinson models?

The consequences of short phases of restricted cerebral blood flow and iron enrichment of striatal tissues resulted in an animal model that could correspond to the basic features of a model for Parkinson's disease. An automatic and computerized hole-board offers simultaneous data on learning and cognitive memory capabilities, learning of distinct patterns of distributed food pellets found and eaten in a given time, switches between different locations of food in the holes and in different layout patterns. Wistar rats after 60 min of bilateral clamping of the carotid arteries (BCCA) under pentobarbital anesthesia received 1.

Consequences of a single short lasting cerebral oligemia and the influence of iron injected into the substantia nigra or in the ventrolateral striatum of the rat. Trigger of Parkinson's disease pathogenesis?

One BCCA-phase (bilateral clamping of carotid arteria) leads to an extensive release of striatal dopamine with a subsequent formation of free radicals (Heim et al., 200b). Early investigations did not show histological damage to cerebral structures after 24 and 60 min duration of a BCCA phase (Melzacka et al.

The analysis system COGITAT for the study of cognitive deficiencies in rodents.

COGITAT is an automated hole board system that, following minimal experimental interventions, makes it possible to measure a variety of parameters associated with learning, memory, relearning, cognition, and cognitive shifts, but also changes in exploratory and sensorimotor performance in rodent models. The individual parameters--that is, overall exploratory activity, number of visits (deep in the hole) into or inspections of (at the upper surface) holes, number of baited, unbaited, or previously baited holes visited or inspected, reinspections of or revisits into any holes, number of pellets eaten, time to find pellets, serial order collection (without intermediate inspections or visits), and reference and working memory errors (visits, inspections, or total)--are obtained simultaneously, and the results are immediately available after the end of each experiment. The system appears to be well suited to neurophysiological, neuropharmacological, and gene-technological investigations in rodent models.

Accuracy of protein biosynthesis: quasi-species nature of proteins and possibility of error catastrophes.

Yeast aminoacyl-tRNA synthetases act in a multi-step process when recognizing their cognate amino acids; this identification event includes "physical" binding and "chemical" proof-reading steps. However, the various enzymes use these single steps at different degrees, and their specificities with regard to the 20 naturally occurring amino acids deviate considerably from each other. The characteristic discrimination factors D were determined for seven synthetases in vitro: the highest specificity with D values between 28,000 and > 500,000 were observed with tyrosyl-tRNA synthetase, the lowest values between 130 and 1700 for lysyl-tRNA synthetase.

Cryoglobulinemia in chronic hepatitis C virus infection: prevalence, clinical manifestations, response to interferon treatment and analysis of cryoprecipitates.

Chronic hepatitis C virus infection can be associated with mixed cryoglobulinemia and systemic vasculitis. The pathogenesis remains poorly understood. 55 consecutive patients with chronic HCI infection (anti-HCV- and serum HCV RNA-positive) were studies prospectively.

A comparison of nucleotide sequences of measles virus L genes derived from wild-type viruses and SSPE brain tissues.

The nucleotide sequences of the large protein (L) gene derived from two wild-type measles viruses (MV) and two SSPE brain-derived viruses have been determined. All sequences have single large open reading frames encoding 2183 amino acid residues. The deduced L proteins are well conserved and the proposed functional domains which have been identified for rhabdo- and paramyxoviruses are completely conserved in all strains.

Reduction of disulfide bonds in an amyloidogenic Bence Jones protein leads to formation of "amyloid-like" fibrils in vitro.

Motivated by the finding that the amino acid sequence of the Bence Jones protein BJP-DIA was identical to that of the main protein component of the amyloid fibrils obtained from the same patient with AL-amyloidosis, (Klafki, H.-W., Kratzin, H.

Clonal expansion of hypermutated measles virus in a SSPE brain.

Nucleotide sequence analysis was carried out to study genes encoding the matrix (M) protein of measles virus (MV) from several regions of the brain of a case of subacute sclerosing panencephalitis. This analysis revealed the presence of MV with "wild-type" sequences as well as variants which had undergone at least five biased hypermutation events (U to C and A to G in the positive strand sequences). Despite the presence of MV variants with genes encoding the intact matrix protein open reading frame, M protein could not be detected in any of the brain regions.

Constant and variable regions of measles virus proteins encoded by the nucleocapsid and phosphoprotein genes derived from lytic and persistent viruses.

The nucleotide sequences of the N and P genes of two wild type measles virus strains JM and CM in two distinct lineages of the virus have been analyzed and compared with those of other MV strains in order to assess which parts of the internal proteins are variable. Most variations in the P protein appear to occur in the N-terminus, while the middle part of the protein (residues 201-350) and the C-terminus are conserved. The C protein varies primarily in its N-terminal amino acids.

Nucleotide sequence of the genes encoding the matrix protein of two wild-type measles virus strains.

The nucleotide sequences of the matrix protein (M) genes of two wild-type measles virus (MV) isolates (JM and CM) have been determined and shown to differ in 56 positions; 31 of these differences are located in the non-coding region and 25 in the coding region of the gene. Most (80%) of the mutations in the coding region are changes to the third base of a codon. A maximum parsimony analysis of the available M gene nucleotide sequences allowed the construction of a tree with at least three lineages or subtypes.

Quantitative densitometry from the point of view of information theory.

The process of quantitative densitometry is analyzed with methods developed in information theory. It is shown that the steps involved in densitometry, e.g.

Essential problems in quantification of proteins following colloidal staining with coomassie brilliant blue dyes in polyacrylamide gels, and their solution.

Quantitative determination of stained proteins following polyacrylamide gel electrophoresis (PAGE) is of increasing interest especially since computer-aided densitometers have become available as well as recipes for sensitive and background-free staining with Coomassie Brilliant Blue dyes. However, avoidance of separation artifacts is not the only essential prerequisite for quantitative evaluation. The local particle density of a protein in a given gel is of critical importance since it determines its stainability.

Isoleucyl-tRNA synthetase from bakers' yeast: multistep proofreading in discrimination between isoleucine and valine with modulated accuracy, a scheme for molecular recognition by energy dissipation.

For discrimination between isoleucine and valine by isoleucyl-tRNA synthetase from yeast, a multistep sequence is established. The initial discrimination of the substrates is followed by a pretransfer and a posttransfer hydrolytic proofreading process. The overall discrimination factor D was determined from kcat and Km values observed in aminoacylation of tRNAIle-C-C-A with isoleucine and valine.

Evaluation of the muscle relaxant properties of a novel beta-carboline, ZK 93423 in rats and cats.

The muscle relaxant action of ZK 93423 (6-benzyloxy-4-methoxymethyl-beta-carboline-3-carboxylate ethyl ester), a novel beta-carboline with agonistic properties at the benzodiazepine receptor, was examined by assessing its effect on the tonic electromyogram (EMG) activity of the gastrocnemiussoleus (GS) muscle of genetically spastic rats and on ventral root reflexes, presynaptic inhibition and fusimotor activity in the spinal cord of decerebrate cats. ZK 93423 (0.1-10.

Spot identification in two-dimensional patterns by a least-squares template matching.

The coordinates of the center of measured spots are nonlinearly transformed to get an optimal match between the transformed coordinates and the given coordinates of a reference pattern. The parameters of the transformation are determined by the minimum of a function of squared distances between all spots of the sample and of the reference pattern. The algorithm requires a priori defined correspondences between some pivot points in the sample and the reference and treats their distances differently from the others.