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G Thill

Publications and source records attributed to G Thill.

11 recordsLinked to original sources
PubMed1996

Utilization of nuclear matrix proteins for cancer diagnosis.

Circulating tumor markers have been used increasingly in recent years as clinical tools for cancer diagnosis and management. This review presents a brief discussion of currently available tumor-associated antigens. Included is an overview of different functional classes of circulating markers and their clinical applications. The limitations of some traditional tumor markers presently in widespread use are discussed in the context of the properties exhibited by an ideal tumor marker. The nuclear matrix provides structural support for the nucleus and plays a dynamic role in the spatial organization of the genome and in the control of DNA replication and transcription. The recovery of increased amounts of specific nuclear matrix proteins in several different cancers has led to the further study of some of these proteins as a new class of tumor markers. Progress on the use of a nuclear matrix protein known as NuMA as a marker for bladder cancer is presented, including results of a recently completed multisite clinical trial. Additional studies on the potential utility of nuclear matrix proteins as markers for prostate cancer are also presented. Nuclear matrix proteins could provide for the development of assays with increased efficacy for the diagnosis and treatment of cancer.

Antibodies, Monoclonal↗
PubMed1994

A three-dimensional model of hepatitis delta virus ribozyme based on biochemical and mutational analyses.

BACKGROUND: Hepatitis delta virus (HDV), which has a single-stranded RNA genome about 1700 nucleotides long, is a satellite virus of hepatitis B, and is associated with a high incidence of fulminant hepatitis and death in infected humans. Like certain pathogenic subviral RNAs that infect plants, HDV RNA features a closed-circular conformation, a rolling-circle mechanism of replication and RNA-catalyzed self-cleaving reactions of both genomic and anti-genomic strands in vitro. The catalytic domains cannot be folded into either the hammerhead or hairpin secondary-structure motifs that have been found in other self-cleaving RNAs. RESULTS: A pseudoknot secondary-structure model has been suggested for the catalytic domain (ribozyme) of HDV RNA. We conducted extensive mutational analyses of regions of the HDV ribozyme predicted in this model to be single stranded, and found that several of them are important for catalytic activity. We used these data, sequence comparisons between different isolates and previously published structural analyses to produce a computer graphic model of the three-dimensional architecture of the HDV ribozyme. CONCLUSIONS: Our model supports the pseudoknotted structure and rationalizes several observations relating to the lengths of the various stems and the sequence requirements of the single-stranded regions. It also provides insight into the catalytic mechanism of the HDV ribozyme. We specifically propose that residues C75, U20 and C21 form the basis of the catalytic region and are close to the cleavable phosphate.

Base Sequence↗
PubMed1993

Structural and sequence elements required for the self-cleaving activity of the hepatitis delta virus ribozyme.

The hepatitis delta virus (HDV) is a subviral RNA that contains a self-cleaving activity that is similar to the ribozyme activity found in certain plant pathogens. However, the sequences surrounding the cleavage site are unrelated to the hammerhead or hairpin ribozyme motifs, and it is considered to be a distinct ribozyme type. We made site-specific changes within two regions of the smallest contiguous HDV sequence that has optimal activity and kinetically analyzed the data at different temperatures to determine the potential roles of the residues. We distinguish between those changes that affect the rate of catalysis and those that promote the formation of inactive structures. We find that nucleotides +45 to +72 downstream from the cleavage site, which can form a hairpin structure, are dispensable for catalytic activity but that they enhance the cleavage efficiency. Nucleotides +17 to +19 and +28 to +30 form Watson and Crick base pairs that are important for activity, but the actual sequence is not critical. In contrast, the nucleotides between +21 and +26 are important for activity, and they may be involved in significant tertiary interactions.

Base Sequence↗
PubMed1991

Self-cleavage of a 71 nucleotide-long ribozyme derived from hepatitis delta virus genomic RNA.

Self-cleavage efficiency of ribozymes derived from hepatitis delta virus (HDV) has been shown to depend on the RNA structure, which in turn may be determined by the length of the considered sequences. Here we describe the construction and functional analysis of a 71 nucleotide-long RNA genomic fragment, Rz71, which carries an 18 nucleotide deletion in a very stable GC-rich stem-loop (stem IV), predicted to be present in several computer-derived secondary structure models. Rz71 is able to undergo self-cleavage under non-denaturing conditions (the t1/2 of the reaction at 37 degrees C is 3 min). The deletion, however, is not neutral, since under the same conditions the non-deleted ribozyme cleaves to 50% in less than 15 sec. Therefore, stem-loop IV seems to play a structural role, not being directly involved in the catalytic reaction, but contributing to the correct positioning of the catalytic core of the HDV ribozyme. Rz71 is the smallest self-cleaving sub-fragment of HDV genomic RNA reported so far.

Base Sequence↗
PubMed1981

[Not Available].

Explore the source record for details and available documents.

Belgium↗
PubMed1977

Membrane phospholipid composition and anaphylactical response of cardiac and smooth muscle fibers in the Rh (D) system.

The anaphylactical response of sensitized smooth and cardiac papillary muscle fibers as target organs was induced by the stimulation of the complement systems in the antigen-antibody reaction of albumin and anti-albumin. However in the Rh (D) system anaphylaxis was only elicited on smooth muscle segments with the corresponding antigen. This discrepancy between both immune systems cannot be explained only by the fact the Rh (D) anti-D reaction does not stimulate the complement activity. Since this antigen-antibody reaction requires a protein phospholipid interaction, the failure of anaphylactical response on cardiac muscle fibers may be due to its phospholipid environment which differed considerably from that of the smooth muscle fibers. Besides the differences in composition and amount of the phospholipids the fatty acid distribution of phosphatidylethanolamine, phosphatidylcholine, sphingomyelin, cardiolipin derived from cardiac or smooth muscle membranes varied clearly. This may influence the protein phospholipid interaction which is essential for the antigen-antibody reaction of the Rh (D) system.

Anaphylaxis↗
PubMedDate not supplied

Structural comparison of the Pichia pastoris alcohol oxidase genes.

In methylotrophic yeasts, alcohol oxidase is the first enzyme in the methanol-utilization pathway. The genome of one such yeast, Pichia pastoris, contains two alcohol oxidase genes, AOX1 and AOX2. Sequence analysis indicated that each gene encodes a similar protein of 663 amino acids. The protein-coding regions of the genes were 92% and 97% homologous at the nucleotide and predicted amino acid sequence levels, respectively. In contrast to homology observed within the protein-coding portions of the AOX genes, no homology was found in either the 5' or 3' non-coding regions. Although alcohol oxidase is found in peroxisomes of P. pastoris, the AOX amino acid sequences did not contain a peptide sequence similar to the peroxisomal transport sequence found at the C-terminus of some peroxisomally located proteins in higher eukaryotes.

Alcohol Oxidoreductases↗