Papers by Guillermo Perales-Ortiz
Manejo Seguro de Material Biológico Infeccioso
Quantitation of H. pylori cytotoxin mRNA by real-time RT-PCR shows a wide expression range that does not correlate with promoter sequences
Microbial Pathogenesis, 2004
Up to 28-fold differences in vacA expression in Helicobacter pylori strains grown in vitro were d... more Up to 28-fold differences in vacA expression in Helicobacter pylori strains grown in vitro were demonstrated by real time quantitative RT-PCR. These large differences in expression were unrelated to putative -35 and -10 motifs or to other untranslated sequences upstream of the ATG start site. The lack of correlation between promoter sequences and the vacA expression levels suggest the potential existence of a bacterial strain-specific factor, as earlier proposed by others on the basis of reporter gene fusions.
FEMS Microbiology Letters, 1999
To monitor changes along the entire Helicobacter pylori vacA gene we carried out full-length sing... more To monitor changes along the entire Helicobacter pylori vacA gene we carried out full-length single-step PCR amplification in 21 gastritis and gastric cancer isolates. HindIII restriction analysis led us to detect a s 400-bp internal insertion in vacA subsequently shown to be a direct 451-bp gene duplication. We found HindIII profiles for 16 genes that allowed their grouping into two restriction patterns that were related to theoretical profiles for previously sequenced Western genes. Comparisons with theoretical HindIII patterns for Japanese isolates appear suggestive of geographical H. pylori clonality. Full-length single-step PCR amplification seems suitable for quick restriction pattern assignment and detection of gene size changes.
Canadian Journal of Animal Science, 2012
Palma-Irizarry, M., Damian-Matsumura, P., Betancourt, M., Romo, S., Perales, G., Lagunas-Martínez... more Palma-Irizarry, M., Damian-Matsumura, P., Betancourt, M., Romo, S., Perales, G., Lagunas-Martínez, A., Madrid-Marina, M. V., Mejía, O. and Ducolomb, Y. 2012. Identification of novel variants of interferon-tau gene in Bighorn sheep ( Ovis canadensis mexicana ), Pelibuey sheep ( Ovis aries ) and its expression in hybrid blastocysts ( Ovis canadensis×Ovis aries ). Can. J. Anim. Sci. 92: 275–283. The major signal for maternal recognition of pregnancy (MRP) in ruminants is interferon-tau (IFNT). Four novel sequences of the IFNT gene were isolated from genomic DNA obtained from blood samples of Bighorn, Pelibuey or the hybrid ewes. The deduced amino acid sequence of the hybrid ewe showed 100% identity with one Bighorn sheep IFNT sequence, suggesting that this sequence was inherited from Bighorn sheep. The high degree of identity between Pelibuey and Bighorn sheep sequences could be a possible explanation for the successful MRP in some Bighorn hybrid pregnancies. In vivo and in vitro domes...
Additional file 1: Table S1. of Infection with Plasmodium berghei ookinetes alters protein expression in the brain of Anopheles albimanus mosquitoes
Identification of differentially displayed proteins in Anopheles albimanus. (XLSX 23 kb)
Additional file 2: Figure S1. of Infection with Plasmodium berghei ookinetes alters protein expression in the brain of Anopheles albimanus mosquitoes
Alignments of the predicted sequence AALB008255-PA from VectorBase data bank, with peptides deriv... more Alignments of the predicted sequence AALB008255-PA from VectorBase data bank, with peptides derived from mass spectra identification (Additional file 1: Table S1). Peptides align only with the carboxyl terminal motif. Box in red indicates initial methionine (ORF) from A. gambiae heat-shock 70 kDa protein AGAP002076-PA. It is highly probable that AALB008255-PA is mischaracterized. (---) indicates no amino acid residues identified and (asterisks) identical amino acid residues. Figure S2. Alignments of the predicted sequence AALB000444-PA from VectorBase data bank, with peptides derived from mass spectra identification. Peptides align only with the amine terminal motif and are numbered according to Additional file 1: Table S1. The red box indicates the initial methionine (ORF) of A. darlingi COP9 signalosome subunit, ADAC010105-PA. We propose that AALB000444-PA is mischaracterized and corresponds to a voltage-dependent anion-selective channel protein. (---) indicates no amino acid resi...
Additional file 3: Table S2. of Infection with Plasmodium berghei ookinetes alters protein expression in the brain of Anopheles albimanus mosquitoes
Identification of differentially displayed proteins in Anopheles albimanus and orthologs in Anoph... more Identification of differentially displayed proteins in Anopheles albimanus and orthologs in Anopheles darlingi and Drosophila melanogaster. (XLSX 18 kb)
A polymorphism in the AT-hook motif of the transcriptional regulator AKNA is a risk factor for cervical cancer
Biomarkers, 2010
The AKNA gene is part of the 9q32 susceptibility locus for cervical cancer. A single-nucleotide p... more The AKNA gene is part of the 9q32 susceptibility locus for cervical cancer. A single-nucleotide polymorphism at codon 1119 of AKNA, yields a biologically relevant amino acid change (R1119Q) at the DNA binding AT-hook motif. Genotype frequencies in 97 allele pairs were: R/R = 0.597, R/Q = 0.278, Q/Q = 0.123. Q/Q homozygosity was present in 8.33% of healthy controls, 16.67% of patients with cervical intraepithelial neoplasia and 75% of cervical cancer patients. These differences are highly significant for the presence of Q/Q in cervical cancer (p = 0.01, odds ratio 3.66, 95% confidence interval 1.35-9.94). Therefore, AKNA appears to be an important genetic factor associated with the risk cervical cancer.
Salud Pública de México, 2017
Expresión de neuropéptidos pleiotrópicos asociados con ecdisis durante el desarrollo del mosquito... more Expresión de neuropéptidos pleiotrópicos asociados con ecdisis durante el desarrollo del mosquito Anopheles albimanus.
[Occupational health and safety: educational intervention for cleaning workers in research sectors]
OBJECTIVE To evaluate the results of educational interven- tion on health and safety regarding pr... more OBJECTIVE To evaluate the results of educational interven- tion on health and safety regarding principles of biosafety in cleaning workers of a health institution. MATERIALS AND METHODS Using concurrent mixed methods, we evaluated a total of 31 workers on their knowledge, attitudes, and practices of biosafety and risk perception. We conducted baseline measurements and two follow-ups. Fractional logistic regression models were fitted with study stage as covariate. Additional models included interactions of study stage with key workers characteristics. Thematic qualitative analysis and triangulation was developed. RESULTS The knowledge (+33.3 points, scale 0-100), attitudes (+10.6), and practices (+23.5) increased significantly in the first follow-up; knowledge de- creased in the second follow-up (p<0.001). The qualitative findings revealed an improvement in risk prevention attitudes and practices, framed by experiences of vulnerability, stigma, and discrimination. CONCLUSIONS The ...
A polymorphism in the AT-hook motif of the transcriptional regulator AKNA is a risk factor for cervical cancer
Biomarkers, 2010
The AKNA gene is part of the 9q32 susceptibility locus for cervical cancer. A single-nucleotide p... more The AKNA gene is part of the 9q32 susceptibility locus for cervical cancer. A single-nucleotide polymorphism at codon 1119 of AKNA, yields a biologically relevant amino acid change (R1119Q) at the DNA binding AT-hook motif. Genotype frequencies in 97 allele pairs were: R/R = 0.597, R/Q = 0.278, Q/Q = 0.123. Q/Q homozygosity was present in 8.33% of healthy controls, 16.67% of patients with cervical intraepithelial neoplasia and 75% of cervical cancer patients. These differences are highly significant for the presence of Q/Q in cervical cancer (p = 0.01, odds ratio 3.66, 95% confidence interval 1.35-9.94). Therefore, AKNA appears to be an important genetic factor associated with the risk cervical cancer.
Quantitation of cytotoxin mRNA by real-time RT-PCR shows a wide expression range that does not correlate with promoter sequences
Microb Pathog, 2004
Salud Pública de México
Objetivo. Evaluar los resultados de una intervención educativa sobre salud y seguridad laboral ba... more Objetivo. Evaluar los resultados de una intervención educativa sobre salud y seguridad laboral bajo principios de bioseguridad en trabajadores y trabajadoras de limpieza de una institución de salud. Material y métodos. Evaluación con métodos mixtos concurrentes sobre conocimientos, actitudes y prácticas en bioseguridad y percepción de riesgos, con medición basal y dos seguimientos, en 31 trabajadores y trabajadoras. Se realizaron modelos fraccionales separados para estimar interacciones de las mediciones. Se hizo análisis cualitativo temático y triangulación metodológica. Resultados. Los conocimientos (+33.3 puntos, escala 0 - 100), actitudes (+10.6) y prácticas (+23.5) incrementaron significativamente en el primer seguimiento; los conocimientos disminuyeron en el segundo seguimiento (p<0.001). Los hallazgos cualitativos revelaron mejora en actitudes y prácticas de prevención frente al riesgo, enmarcados por experiencias de vulnerabilidad, estigma y discriminación. Conclusione...
Parasites & Vectors, 2016
Background: The behaviour of Anopheles spp. mosquitoes, vectors for Plasmodium parasites, plays a... more Background: The behaviour of Anopheles spp. mosquitoes, vectors for Plasmodium parasites, plays a crucial role in the propagation of malaria to humans. Consequently, it is important to understand how the behaviour of these mosquitoes is influenced by the interaction between the brain and immunological status. The nervous system is intimately linked to the immune and endocrine systems. There is evidence that the malaria parasite alters the function of these systems upon infecting the mosquito. Although there is a complex molecular interplay between the Plasmodium parasite and Anopheles mosquito, little is known about the neuronal alteration triggered by the parasite invasion. The aim of this study was to analyse the modification of the proteomic profile in the An. albimanus brain during the early phase of the Plasmodium berghei invasion. Results: At 24 hours of the P. berghei invasion, the mosquito brain showed an increase in the concentration of proteins involved in the cellular metabolic pathway, such as ATP synthase complex alpha and beta, malate dehydrogenase, alanine transaminase, enolase and vacuolar ATP synthase. There was also a rise in the levels of proteins with neuronal function, such as calreticulin, mitofilin and creatine kinase. Concomitantly, the parasite invasion repressed the expression of synapse-associated proteins, including enolyl CoA hydratase, HSP70 and ribosomal S60 proteins. Conclusions: Identification of upregulated and downregulated protein expression in the mosquito brain 24 hours after Plasmodium invaded the insect midgut paves the way to better understanding the regulation of the neuro-endocrine-immune system in an insect model during parasite infection.
Relación entre la densidad bacteriana, los genes vac A y cag A con la respuesta al tratamiento para Helicobacter pylori en pacientes con Úlcera Péptica y/o Gastritis Crónica Folicular
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Papers by Guillermo Perales-Ortiz