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R Fuchs

Publications and source records attributed to R Fuchs.

At least 19 recordsLinked to original sources
PubMed1997

IMAGE cDNA clones, UniGene clustering, and ACeDB: an integrated resource for expressed sequence information.

In this study we describe a new information resource that provides integrated access to information on IMAGE (integrated molecular analysis of genomes and their expression) cDNA library clones and derived expressed sequence tags (ESTs). We have developed an automated procedure that collates data from various public sources into a single ACeDB database. This database is a valuable tool for electronic cloning experiments and gene expression studies. It allows researchers to find information about cDNA libraries, plate addresses, insert sizes, and sequence data for IMAGE clones, the assignment of ESTs to UniGene clusters, and the chromosomal location of those genes in an efficient, graphically oriented manner.

Cloning, Molecular↗
PubMed1992

[Recurrence of Hodgkin's disease after advanced primary stages. German Hodgkin's Study Group].

In a multicentre study on the treatment of Hodgkin's disease, 88 out of 297 patients with primary advanced stages IIIB/IV failed to respond to alternating COPP/ABVD chemotherapy +/- radiotherapy. They may be broken down as follows: tumour progression under current therapy (PD) 23/28, partial remission at the end of treatment (PR) 28/88, early nodal recurrence 13/88, late nodal recurrence 15/88, extranodal recurrence 7/88, unclear localisation 1/88. Thirty-six months after noting failure of treatment, 45% of all patients were still alive. The prognosis was poorest in the case of primary PD. Only 1/23 of these patients experience lasting complete remission thanks to salvage treatment (cCR). Eleven patients with an exclusively nodal recurrence experienced a cCR on treatment with radiation alone, and may be considered a low-risk recurrence group. For a high-risk recurrence group (n = 57), indication for high-dose chemotherapy with subsequent autologous bone marrow transplantation (HDC/ABMT) should have been recognized on the basis of the present definition. The survival probability of these patients, who only received conventional salvage treatment, was 38% after 30 months (95% confidence limit, 22 to 54%). These data would not appear to be appreciably poorer than those reported in the literature for comparable patients receiving HDC/ABMT. Only a randomized comparison would be capable of showing whether HDC/ABMT is superior to high-dose conventional chemotherapy with haematopoietic growth factors. It is proposed that such a therapeutic trial should be initiated as soon as possible.

Adolescent↗
PubMed1992

Sensitivity to vanadate and isoforms of subunits A and B distinguish the osteoclast proton pump from other vacuolar H+ ATPases.

Analysis of proton (H+) transport by inside-out vesicles derived from highly purified chicken osteoclast (OC) membranes has revealed the presence of a newly discovered type of vacuolar H+ ATPase (V-ATPase). Unlike vesicles derived from any other cell type or organelle, H+ transport in OC-derived vesicles is sensitive to V-ATPase inhibitors (N-ethylmaleimide and Bafilomycin A1) and vanadate (IC50, 100 microM), an inhibitor previously found to affect only P-type ATPases. The OC H+ ATPase contains several V-like subunits (115, 39, and 16 kDa) but subunits A and B of the catalytic domain of the enzyme differ from that of other V-ATPases. In OCs, subunit A has a mass of 63 kDa instead of the 67-70 kDa expressed in monocytes, macrophages, and kidney microsomes, which contain a vanadate-insensitive H+ ATPase. Moreover, two types of 57- to 60-kDa B subunits are also found: one is expressed predominantly in OCs and the other is expressed in kidney microsomes. The OC H+ pump may therefore constitute a class of H+ ATPase with a unique pharmacology and specific isoforms of two subunits in the catalytic portion of the enzyme. This H+ ATPase is involved in resorption of bone and may be expressed in a cell-specific manner, thereby opening possibilities for therapeutic intervention.

Animals↗
PubMed1992

Genetic polymorphism of the gene encoding the outer surface protein A (OspA) of Borrelia burgdorferi.

The genes coding for the outer surface protein (OspA) of Borrelia burgdorferi, the causative agent of Lyme borreliosis have been cloned and sequenced. Two German strains (skin isolate PKo and cerebrospinal fluid isolate PBi) have been analyzed. Using an OspA-specific monoclonal antibody (L32 2E7) for immunological screening of a genomic pUC18 library of B. burgdorferi strain PKo, and OspA-producing clone was detected and subclones containing the open reading frame were constructed. The gene coding for the OspA protein of B. burgdorferi strain PBi was amplified using polymerase chain reaction (PCR) and cloned in pUC8. The open reading frame of both ospA genes consists of 822 nucleotides corresponding to a protein of 273 amino acids. Both proteins have a calculated molecular mass of 29.6 kDa. Molecular analysis revealed significant differences between each other and to already-published sequences of ospA of B. burgdorferi strains B31, ZS7 and N40 (the ospA genes of B31, ZS7 and N40 are nearly identical). The deduced amino acid sequences of the OspA protein of strains PKo and PBi showed a homology of 83% to each other and 77% and 80%, respectively, to OspA protein of strain B31. The three proteins contain a variable middle region, whereas the N and the C terminus are conserved. This unexpected high dissimilarity of the ospA genes may be important in respect to vaccination studies and diagnostic procedures (i.e., development of PCR primers or serodiagnostic antigens). Moreover, the molecular heterogeneity of OspA confirms three out of seven immunologically defined OspA serotypes of a recently proposed OspA serotyping system.

Amino Acid Sequence↗
PubMed1992

Cross-reactive proteins of Borrelia burgdorferi.

The specificity of serological tests for Lyme borreliosis is impaired by cross-reacting antibodies. In order to select antigens for more specific tests, specific and cross-reactive proteins of Borrelia burgdorferi must be identified. Therefore, to analyze cross reactions of Borrelia burgdorferi with other bacteria, rabbit immune sera against heterologous bacteria (Borrelia hermsii, Treponema pallidum, Treponema phagedenis, Leptospira interrogans (serogroup grippotyphosa), Neisseria meningitidis, Haemophilus influenzae, Yersinia enterocolitica (serotypes O3 and O9), Campylobacter jejuni, Listeria monocytogenes O1, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhimurium, Shigella flexneri and Legionella micdadei) were examined by Western blot using Borrelia burgdorferi as antigen. Broad cross reactivity was shown for Borrelia proteins of the 60-75 kDa range. Other broadly cross-reacting proteins were at the level of p40, p33 and two proteins in the range of 20 kDa. Some of the cross reactions were eliminated by absorption of the sera with Treponema phagedenis. The absorbed antibodies were directed mainly against bands at the level of p33 and bands of the 60 to 75 kDa range. Showing the lowest potential for cross reactivity, p100, p41, OspA and pC seem to be the most suitable antigens for serodiagnosis. In contrast to p100 and OspA, however, p41 and pC showed cross reactivity with immune sera against bacteria not belonging to the genus Borrelia.

Antigens, Bacterial↗
PubMed1992

Ochratoxin A in blood and its pharmacokinetic properties.

Since there are pathomorphological similarities between porcine mycotoxic nephropathy caused by ochratoxin A and Balkan endemic nephropathy (BEN), it has been suggested that the same aetiological agent has a role in BEN. Based on the results from several field and experimental studies carried out on pigs, an appropriate analytical method of monitoring possible human exposure to ochratoxin A was developed. The toxicokinetic properties of the toxin were species specific, although in all the animal species studied (with the exception of fish), as well as in humans, two binding proteins were found in the plasma. The monkey had the longest elimination half-life of the toxin, 510 hr, in contrast to the fish whose elimination half-life was only 0.68 hr. The fish kidney displayed a specific pattern of distribution. In the laying quail the most prominent observation was the accumulation of labelled ochratoxin A in egg yolk. Generally, [14C]ochratoxin A was eliminated rapidly from the quail body, but had a long retention time in the circulating blood in the mouse. Although the elimination of ochratoxin A from the body depending on its binding to plasma constituents, the existence of enterohepatic circulation might have been partially responsible for its prolonged retention and elimination from the body of mammals. The toxicokinetic profile of ochratoxin A did not contradict the mycotoxic hypothesis in the aetiology of BEN.

Animals↗
PubMed1992

CLUSTAL V: improved software for multiple sequence alignment.

The CLUSTAL package of multiple sequence alignment programs has been completely rewritten and many new features added. The new software is a single program called CLUSTAL V, which is written in C and can be used on any machine with a standard C compiler. The main new features are the ability to store and reuse old alignments and the ability to calculate phylogenetic trees after alignment. The program is simple to use, completely menu driven and on-line help is provided.

Phylogeny↗
PubMed1992

MacT: Apple Macintosh programs for constructing phylogenetic trees.

MacT is a set of programs for the Apple Macintosh to construct and evaluate unrooted trees derived from amino acid sequences using a distance matrix method. Programs are designed on a 'one program--one task' basis for (i) determining the branching order in trees consisting of four or five species and calculating various statistical measures, (ii) calculating statistical measures for all possible topologies of unrooted trees and (iii) generating and evaluating trees derived from bootstrapped samples. With four auxiliary programs unrooted trees can be built for maximal 26 species, and the robustness of topologies be tested by bootstrapping.

Algorithms↗
PubMed1992

Molecular analysis and expression of a Borrelia burgdorferi gene encoding a 22 kDa protein (pC) in Escherichia coli.

We describe the cloning and expression of the pc gene which encodes a major immunodominant protein of Borrelia burgdorferi, the causative agent of Lyme borreliosis. The pC protein was purified from lysates of B. burgdorferi strain PKo. After tryptic digestion of the pC protein the resulting oligopeptides were applied to a gas-phase sequenator. Thus partial amino acid sequences were obtained. The deduced oligonucleotides were used as hybridization probes. After Southern blotting a reactive band in the 3 kb range of PstI-digested genomic DNA was detected. The insertion of these fragments into pUC vectors finally resulted in pc-positive Escherichia coli clones. The gene (encoding a protein with 212 amino acids) was expressed in E. coli with varying deletions at the 5' end. A sequence comparison with other outer membrane proteins of B. burgdorferi indicates a processing of pC that is similar to that of lipoproteins.

Amino Acid Sequence↗
PubMed1992

Synthesis of 14C-ochratoxin A and 14C-ochratoxin B and a comparative study of their distribution in rats using whole body autoradiography.

Methods for preparation of labelled ochratoxin A and B are described. The method for preparation of labelled ochratoxin B involves the synthesis of the azide of ochratoxin beta via the mixed anhydride and subsequent conjugation to labelled phenylalanine to yield 14C-ochratoxin B. The labelled ochratoxins were injected into male Wistar rats and after different survival times they were sacrificed and subjected to whole body autoradiography. The distribution pattern of ochratoxin A in the rat did not differ from that earlier registered for mouse. The previously known, high susceptibility of rats (and not mice) to ochratoxin A-induced cancer could thus not be explained by an accumulation of the toxin in specific cells or organs. The distribution patterns of ochratoxin A and B were almost congruent--the only apparent difference being a much longer retention of the labelled ochratoxin A in the blood compared to ochratoxin B, which was much faster excreted. When analyzing tissue extracts for labelled metabolites only the extracts from the rats injected with ochratoxin B were found to contain easily detectable concentrations, while no metabolites of ochratoxin A were seen.

Animals↗
PubMed1992

The osteoclast proton pump differs in its pharmacology and catalytic subunits from other vacuolar H(+)-ATPases.

Osteoclasts are multinucleated cells derived from the mononuclear phagocyte system in the hematopoietic bone marrow. Their function is to resorb bone during skeletal growth and remodeling. They perform this function by acidifying an enclosed extracellular space, the bone resorbing compartment. Analysis of proton transport by inside-out vesicles derived from highly purified chicken osteoclast membranes has revealed the presence of a novel type of multisubunit vacuolar-like H(+)-ATPase. Unlike H(+)-ATPases derived from any other cell type or organelle, proton transport and ATPase activity in osteoclast vesicles are sensitive to two classes of inhibitors, namely V-ATPase inhibitors [N-ethyl-maleimide (NEM) and bafilomycin A1] and vanadate (IC50 100 mumol l-1), an inhibitor previously found to affect only P-ATPases. The osteoclast V-ATPase morphologically resembles vacuolar proton pumps and contains several vacuolar-like subunits (115 x 10(3), 39 x 10(3) and 16 x 10(3)M(r)), demonstrated by Western blot analysis. Subunits A and B of the catalytic domain of the enzyme, however, differ from that of other V-ATPases. In osteoclasts, subunit A has an M(r) of 63 x 10(3) instead of 67 x 10(3)-70 x 10(3); in contrast, monocytes, macrophages and kidney microsomes, which contain a vanadate-insensitive H(+)-ATPase, express the classical subunit A (70 x 10(3)M(r)). Moreover, two types of 57 x 10(3)-60 x 10(3)M(r) B subunits are also found: they are differentially recognized by antibodies and one is expressed predominantly in osteoclasts and the other in bone marrow cells and in kidney microsomes. Preliminary cloning data have indicated that the B subunit expressed in osteoclasts may be similar to the brain isoform. The osteoclast proton pump may, therefore, constitute a novel class of V-ATPase, with a unique pharmacology and specific isoforms of two subunits in the catalytic portion of the enzyme.

Adenosine Triphosphatases↗
PubMed1992

Animal studies related to Balkan endemic nephropathy.

Basic field studies related to the animal population were performed in the region of Slavonski Brod, Republic of Croatia, where Balkan endemic nephropathy is an endemic disease. Pathological changes in several animal species from the locality were examined. The pig population in the area is numerous. Morphologically and physiologically pigs make an excellent animal model for studies of human diseases. Their use in studies should be encouraged, especially because there is a possibility that pigs and humans suffer from the same type of intoxication with a specific xenobiotic of natural origin. According to the mycotoxin theory about the aetiology of Balkan endemic nephropathy, pork meat might be one of the possible hazards for humans. Experiments on laboratory animals provide an excellent possibility to monitor several aspects of pathogenesis and all stages of pathomorphological changes which might then be correlated with Balkan endemic nephropathy. However, the experimental species should be critically chosen because some spontaneous, species-specific lesions of the kidneys are easily mistaken for changes induced experimentally.

Animals↗
PubMed1991

Clonal deletion of V beta 14-bearing T cells in mice transgenic for mammary tumour virus.

Autoreactive T lymphocytes are clonally deleted during maturation in the thymus. Deletion of T cells expressing particular receptor V beta elements is controlled by poorly defined autosomal dominant genes. A gene has now been identified by expression of transgenes in mice which causes deletion of V beta 14+ T cells. The gene lies in the open reading frame of the long terminal repeat of the mouse mammary tumour virus.

Amino Acid Sequence↗
PubMed1991

Human exposure to ochratoxin A.

Over a nine-year period during screening campaigns in villages where Balkan nephropathy is endemic, human blood samples were collected and analysed for ochratoxin A. The incidence of positive samples was 0.5-2.5%. Dried beans were found to be more frequently contaminated with the toxin than other food commodities. In view of a specific accumulation of ochratoxin A observed in eggs, more attention should be paid to contamination of this food with ochratoxin A.

Balkan Nephropathy↗