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Carlos Barrero

Publications and source records attributed to Carlos Barrero.

6 recordsLinked to original sources
PubMed2006

Genetically altered expression of spermidine/spermine N1-acetyltransferase affects fat metabolism in mice via acetyl-CoA.

The acetylating enzyme, spermidine/spermine N1-acetyltransferase, participates in polyamine homeostasis by regulating polyamine export and catabolism. Previously, we reported that overexpression of the enzyme in cultured tumor cells and mice activates metabolic flux through the polyamine pathway and depletes the N1-acetyltransferase coenzyme and fatty acid precursor, acetyl-CoA. Here, we investigate this possibility in spermidine/spermine N1-acetyltransferase transgenic mice in which the enzyme is systemically overexpressed and in spermidine/spermine N1-acetyltransferase knock-out mice. Tissues of the former were characterized by increased N1-acetyltransferase activity, a marked elevation in tissue and urinary acetylated polyamines, a compensatory increase in polyamine biosynthetic enzyme activity, and an increase in metabolic flux through the polyamine pathway. These polyamine effects were accompanied by a decrease in white adipose acetyl- and malonyl-CoA pools, a major (20-fold) increase in glucose and palmitate oxidation, and a distinctly lean phenotype. In SSAT-ko mice, the opposite relationship between polyamine and fat metabolism was observed. In the absence of N1-acetylation of polyamines, there was a shift in urinary and tissue polyamines indicative of a decline in metabolic flux. This was accompanied by an increase in white adipose acetyl- and malonyl-CoA pools, a decrease in adipose palmitate and glucose oxidation, and an accumulation of body fat. The latter was further exaggerated under a high fat diet, where knock-out mice gained twice as much weight as wild-type mice. A model is proposed whereby the expression status of spermidine/spermine N1-acetyltransferase alters body fat accumulation by metabolically modulating tissue acetyl- and malonyl-CoA levels, thereby influencing fatty acid biosynthesis and oxidation.

Acetyl Coenzyme A↗
PubMed2006

Learning strategies used by cardiology residents: assessment of learning styles and their correlations.

OBJECTIVE: To identify the learning styles of a group of cardiology residents (R) undergoing a training program at the University of Buenos Aires and to identify correlations of these styles. METHODS: Statistical data were obtained through a 120-question survey developed by Vermunt and colleagues, which identified four different learning styles: construction-directed; reproduction-directed; application-directed; and undirected. Four variables were identified [gender, previous experience as a teaching assistant (TA) in medical school, university final average (FA) and the public or private institution/centre of origin] in order to analyse level of correlation with learning styles (LS). Between April 2001 and April 2002, 149 residents (R) completed the survey. Average age was 29 (+/-2.7) years old; with 63% being men. FINDINGS: The predominant LS were oriented toward knowledge application. In terms of variables, no differences regarding gender were detected; the R with TA showed undirected LS characteristics; those with a low FA registered a tendency towards reproduction-directed LS; and those residents at public/state medical centres indicated construction-directed LS tendencies. CONCLUSION: An application-directed learning style predominates in this group of residents. Information regarding learning styles can provide foundations upon which arguments can be made for changes in education that are traditionally not evidence-based.

Adult↗
PubMed2005

Mycobacterium tuberculosis Rv2536 protein implicated in specific binding to human cell lines.

The gene encoding the Mycobacterium tuberculosis Rv2536 protein is present in the Mycobacterium tuberculosis complex (as assayed by PCR) and transcribed (as determined by RT-PCR) in M. tuberculosis H37Rv, M. tuberculosis H37Ra, M. bovis BCG, and M. africanum strains. Rabbits immunized with synthetic polymer peptides from this protein produced antibodies specifically recognizing a 25-kDa band in mycobacterial sonicate. U937 and A549 cells were used in binding assays involving 20-amino-acid-long synthetic peptides covering the whole Rv2536 protein sequence. Peptide 11207 (161DVFSAVRADDSPTGEMQVAQY180) presented high specific binding to both types of cells; the binding was saturable and presented nanomolar affinity constants. Cross-linking assays revealed that this peptide specifically binds to 50 kDa U937 cell membrane and 45 kDa A549 cell membrane proteins.

Amino Acid Sequence↗
PubMed2003

A highly infective Plasmodium vivax strain adapted to Aotus monkeys: quantitative haematological and molecular determinations useful for P. vivax malaria vaccine development.

The New World primate Aotus nancymaae is susceptible to infection by the human malaria parasite Plasmodium vivax and has therefore been recommended by the World Health Organization as a model for malaria vaccine candidate evaluation. We report the isolation, adaptation, titration and genetic characterization of a P. vivax wild strain in splenectomized A. nancymaae monkeys. Parasitemia remained high after 22 passages, reaching 7.88% by Giemsa and Acridine Orange staining and Real-Time PCR determination, making this P. vivax strain a highly infective and reliable asset to be used in P. vivax biological studies and vaccine development.

Animals↗
PubMedDate not supplied

Quantifying Aotus monkey cytokines by real-time quantitative RT-PCR.

Aotus spp. monkeys are considered the ideal model for studying the progress of malarial infection and the immune response it elicits. We describe the use of a recently developed technique, real-time quantitative RT-PCR, to quantify several Aotus monkey cytokine mRNAs involved in Th1/Th2 responses (IL-4, IL-10, TNF-beta and IFN-gamma). Specific primers were designed for each cytokine and standard curves were constructed using serial dilutions of pDNA containing each target sequence. Results were normalized to GAPDH housekeeping gene expression levels. Standard curves showed high correlation coefficients and were linear over a wide range of copy numbers. Quantification of Aotus samples showed little intra- and inter-experiment variation, thus, the technique has proven to be highly reproducible and sensitive allowing us to detect as little as 25 copies/microl of target DNA. This technique will allow studying Th1 and Th2 cytokine patterns elicited in response to infection for prospectively evaluating the efficacy of malarial vaccines.

Animals↗