Search results for "Strand"

Molecular communication relays for dynamic cross-regulation of self-sorting fibrillar self-assemblies

2021

Description

Nucleoside Analogue Mutagenesis of a Single-Stranded DNA Virus: Evolution and Resistance

2012

ABSTRACT It has been well established that chemical mutagenesis has adverse fitness effects in RNA viruses, often leading to population extinction. This is mainly a consequence of the high RNA virus spontaneous mutation rates, which situate them close to the extinction threshold. Single-stranded DNA viruses are the fastest-mutating DNA-based systems, with per-nucleotide mutation rates close to those of some RNA viruses, but chemical mutagenesis has been much less studied in this type of viruses. Here, we serially passaged bacteriophage ϕX174 in the presence of the nucleoside analogue 5-fluorouracil (5-FU). We found that 5-FU was unable to trigger population extinction for the range of conce…

Delayed lysis confers resistance to the nucleoside analogue 5-fluorouracil and alleviates mutation accumulation in the single-stranded DNA bacterioph…

2014

ABSTRACT Rates of spontaneous mutation determine viral fitness and adaptability. In RNA viruses, treatment with mutagenic nucleoside analogues selects for polymerase variants with increased fidelity, showing that viral mutation rates can be adjusted in response to imposed selective pressures. However, this type of resistance is not possible in viruses that do not encode their own polymerases, such as single-stranded DNA viruses. We previously showed that serial passaging of bacteriophage ϕX174 in the presence of the nucleoside analogue 5-fluorouracil (5-FU) favored substitutions in the lysis protein E (P. Domingo-Calap, M. Pereira-Gomez, and R. Sanjuán, J. Virol. 86: 9640–9646, 2012, doi:10…

dsRNA-functionalized multifunctional gamma-Fe2O3 nanocrystals: a tool for targeting cell surface receptors.

2008

Nanomaterial-based cocaine aptasensors.

2015

Up to now, many different methods have been developed for detection of cocaine, but most of these methods are usually time-consuming, tedious and require special or expensive equipment. Therefore, the development of simple, sensitive and rapid detection methods is necessary. In the last decade, aptamers have been used as a new biosensor platform for detection of cocaine in different samples. Aptamers are artificial single-stranded DNA or RNA oligonucleotides capable of binding to specific molecular targets with high affinity and if integrated to nanomaterials, it may lead in precise methods for cocaine detection in the common laboratories. In this review, recent advances and applications of…

Strong founder effects in BRCA1 mutation carrier breast cancer patients from Latvia

1999

Germ-line mutations of the BRCA1 gene account for approximately half of the cases of hereditary breast/ovarian cancers. We have screened index patients from 15 breast cancer families and 8 sporadic breast cancer patients from Latvia for mutations in all coding exons of the BRCA1 gene, using combined Heteroduplex Analysis/SSCP followed by direct sequencing of the variants. BRCA1 germ-line mutations proved to be frequent in Latvian breast cancer patients, also in moderate-risk families and sporadic patients. Out of 23 cases a total of 8 patients (35%) exhibited three different mutations (5382insC, C61G, 4153delA). Interestingly, these three recurrent mutations accounted for all mutations in o…

Analysis of the RET, GDNF, EDN3, and EDNRB genes in patients with intestinal neuronal dysplasia and Hirschsprung disease

2001

BACKGROUNDHirschsprung disease (HSCR) is a frequent congenital disorder with an incidence of 1 in 5000 live births, characterised by the absence of parasympathetic intramural ganglion cells in the hindgut resulting in intestinal obstruction in neonates and severe constipation in infants and adults. Intestinal neuronal dysplasia (IND) shares clinical features with HSCR but the submucosal parasympathetic plexus is affected. IND has been proposed as one of the most frequent causes of chronic constipation and is often associated with HSCR.METHODSWe examined 29 patients diagnosed with sporadic HSCR, 20 patients with IND, and 12 patients with mixed HSCR/IND for mutations in the coding regions of …

C-erbB-2-oncogene expression in breast carcinoma: Analysis by S1 nuclease protection assay and immunohistochemistry in relation to clinical parameters

1992

The c-erbB-2 mRNA was detected by the S1 nuclease protection assay and Northern blotting in breast cancer tissues. In contrast to the Northern blot analysis which has been used in all recent publications concerning c-erbB-2 expression on the level of RNA, the S1-nuclease protection assay has distinct advantages with respect to sensitivity, reproducibility, and handling of radioactive probes. We compared the expression of c-erbB-2 in 120 breast carcinomas which were operated in the years 1989-1990 on the level of the mRNA (S1 nuclease protection assay) and the protein (immunohistochemistry), respectively. In general, results obtained with both methods were in good agreement. Only minor diffe…

ISOLATION OF RAT CDNA CLONES CODING FOR THE AUTOANTIGEN SS-B/LA - DETECTION OF SPECIES-SPECIFIC VARIATIONS

1993

Clones of cDNA coding for the autoantigen La (or SS-B) were isolated from a library made from rat liver. A comparison of the rat La cDNA (encoding from nt 38 to 1281 for rat La protein) with the sequences known for human and bovine La protein resulted in the identification of species-specific inserts. The inserts seem to be the result of multiplication of flanking sequences during evolution. In addition to these variations, we observed that rat La cDNAs exhibit non-canonical polyadenylation sites. Finally, a databank search resulted in the identification of a DNA sequence originally termed as TAG or TSG20X (GenBank accession No. X61893) which represents the C terminus of mouse La/SS-B prote…

Racemic S ‐(ethylsulfonyl)‐ dl ‐cysteine N ‐Carboxyanhydrides Improve Chain Lengths and Monomer Conversion for β‐Sheet‐Controlled Ring‐Opening Polyme…

2020

The secondary structure formation of polypeptides not only governs folding and solution self-assembly but also affects the nucleophilic ring-opening polymerization of alpha-amino acid-N-carboxyanhydrides (NCAs). Whereby helical structures are known to enhance polymerization rates, beta-sheet-like assemblies reduce the propagation rate or may even terminate chain growth by precipitation or gelation. To overcome these unfavorable properties, racemic mixtures of NCAs can be applied. In this work, racemicS-(ethylsulfonyl)-dl-cysteine NCA is investigated for the synthesis of polypeptides, diblock and triblock copolypept(o)ides. In contrast to the polymerization of stereoregularS-(ethylsulfonyl)-…