PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 2620200

[Study of new brain peptides using genetic engineering methods].

A Dresse·D Marechal
View original source ↗Export metadata ↓

Abstract

Using the methods of molecular biology, we have been able to clone 5 rat brain specific cDNAs coding for brain specific proteins. The partial sequencing of the first of those clones gave no homology with the genes contained in Genebank and EMBL data bank. In the future, we intend to look for a possible effect of those brain specific proteins on the neuronal activity of rat brain neurons.

Explore related subjects

DNA, CircularGene LibraryGenetic EngineeringHumansNerve Tissue ProteinsNeural ConductionSelection, GeneticEnglish AbstractJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A Dresse, D Marechal. 1989. [Study of new brain peptides using genetic engineering methods].. https://pubmed.ncbi.nlm.nih.gov/2620200/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Real-time PCR quantitation of hepatitis B virus total DNA and covalently closed circular DNA in peripheral blood mononuclear cells from hepatitis B virus-infected patients.

It remains unclear whether hepatitis B virus (HBV) replicates in extrahepatic tissues, and particularly in peripheral blood mononuclear cells (PBMCs), which may serve as a reservoir for the maintenance of infection. A real-time PCR assay for the quantitation of total and covalently closed circular (ccc) HBV DNA in serum and in PBMCs was developed. This assay was highly sensitive (detection limit: 27 IU/mL), linear over a wide range (9 log10), and was displayed high inter- and intra-assay reproducibility for the quantitation of total DNA. Genotypes A to E were detected and the results were consistent with those obtained with the COBAS Amplicor HBV Monitor Test. The specificity of the methodology was increased by prior treatment with an enzyme that digests relaxed circular DNA, and the elimination of background signals from virus adsorbed to the surface of PBMCs. HBV DNA was detected in the serum and PBMCs of 12 HBsAg-positive patients, with less than 1% in the cccDNA form. In conclusion, the quantitation of total and ccc HBV DNA in PBMCs is potentially useful as a non-invasive marker, and may help to increase our knowledge of the natural history of hepatitis B.

DNA, Circular↗
PubMed2006

PCR-based detection is unable to consistently distinguish HIV 1LTR circles.

Quantitative PCR methods are routinely used to measure multiple HIV cDNA forms, including linear cDNA, early and late reverse transcripts, 2LTR circles, and integrated provirus. PCR-based methods for the detection of 1LTR circles have been proposed, but are complicated by the inherent homology of the LTR sequence present in all cDNA forms. Amplicons with variable lengths of homology showed that it is difficult to discriminate 1LTR circles faithfully from other cDNA forms. Addition of formamide, DMSO, or glycerol did not eliminate amplification of spurious products. Thus, detection of 1LTR circles by PCR is not reliable.

DNA, Circular↗
PubMed2006

Single-molecule measurements of trapped and migrating circular DNA during electrophoresis in agarose gels.

The effect of agarose gel concentration and field strength on the electrophoretic trapping of open (relaxed) circular DNA was investigated using microscopic measurements of individual molecules stained with a fluorescent dye. Three open circles with sizes of 52.5, 115, and 220 kbp were trapped by the electric field (6 V/cm) and found to be predominately fixed and stretched at a single point in the gel. The length of the stretched circles did not significantly change with agarose concentration of the gels (mass fractions of 0.0025, 0.01, and 0.02). The relaxation kinetics of the trapped circles was also measured in the gels. The relaxation of the large open circles was found to be a slow process, taking several seconds. The velocity and average length of the 52.5 kbp open circles and 48.5 kbp linear DNA were measured during electrophoresis in the agarose gels. The velocity increased when the agarose concentrations were lowered, but the average length of the open-circle DNA (during electrophoresis) did not significantly change with agarose gel concentrations. The circles move through the gels by cycles of stretching and relaxation during electrophoresis. Linear dichroism was also used to investigate the trapping and alignment of the 52.5 kbp open circles. The results in this study provide information that can be used to improve electrophoretic separations of circular DNA, an important form of genetic material and commonly used to clone DNA.

DNA, Circular↗