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A Sánchez

Publications and source records attributed to A Sánchez.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of the satellite DNA Msat-160 from the species Chionomys nivalis (Rodentia, Arvicolinae).

The satellite DNA Msat-160 has been previously characterized in several species of the genus Microtus. Here we present the characterization of Msat-160 from Chionomys nivalis, a species with a very primitive karyotype. As in other Microtus species analyzed, C. nivalis Msat-160 is AT rich, has a monomer length of 160 bp, is undermethylated and is mainly located in all the pericentromeric heterochromatin of all autosomes and the X chromosome, but is completely absent from the Y chromosome. Hence, our results support the hypothesis that Msat-160 was initially distributed in the pericentromeric heterochromatin of all autosomes and the X chromosome. The taxonomic status of the genus Chionomys in relation to the genus Microtus is a very interesting issue, so we constructed phylogenetic dendrograms using Msat-160 sequences from several Microtus species. Although the results were not informative about this issue, the presence of Msat-160 in C. nivalis and Microtus species suggested that both genera are closely related and that this satellite DNA was present in the common ancestor. Studies of Msat-160 in different arvicoline species could help to determine the origin of this satellite and, perhaps, to establish the phylogenetic relationships of some arvicoline groups.

Animals↗
PubMed2006

Occurrence and preliminary study of antimicrobial resistance of enterococci isolated from dairy goats in Spain.

The present study performed in Spain was designed to investigate the occurrence and antimicrobial resistance of enterococci in faecal and bulk tank milk samples from 222 healthy Murciano-Granadina dairy goats reared on 12 farms. Enterococci were isolated in 54.5% and 63.6% of the faecal and bulk tank milk samples, respectively. Enterococci were detected more frequently from goat kids (70%) than from replacement animals (44.4%) and adults (56.4%). Seven species were found in the faecal samples but the most common species detected were Enterococcus faecium (32.3%), Enterococcus faecalis (27.6%) and Enterococcus hiriae (22%). In contrast, only E. faecium and E. faecalis were found in the bulk tank milk samples. According to NCCLS (2002), of the 134 strains studied, 17 (12.7%) were resistant to at least 7 antimicrobials and 14 of these strains were resistant to vancomycin.

Animals↗
PubMed2006

PLGA:poloxamer and PLGA:poloxamine blend nanostructures as carriers for nasal gene delivery.

We have recently reported the formation of a new type of nanoparticles consisting of blends of poly (lactic-co-glycolic acid) (PLGA) and polyethylene oxide (PEO) derivatives, which exhibit the capacity to associate and release plasmid DNA in a controlled manner. In the present work our goal was to investigate the ability of these nanoparticles to overcome cellular and mucosal barriers (i.e. nasal mucosa) and thus, to work as gene delivery carriers. First, we studied the in vitro cellular uptake (HEK 293 cell line) of FITC-labelled plasmid DNA nanoencapsulated in PLGA: Pluronic F68 and PLGA: Tetronic T904 particles by confocal microscopy. Second, we investigated the uptake of rhodamine-labelled nanoparticles by the nasal mucosa following intranasal administration to mice. Third, we monitored the immune response generated by the nanoparticles containing a beta-galactosidase encoding gene, following nasal administration to mice, using the ELISA technique. The results of the in vitro cell culture studies showed the ability of these new nanoparticles to enter the cells and transport the associated DNA molecule across the cell membrane. Moreover, the results obtained following in vivo administration of the fluorescent nanoparticles evidenced their capability to overcome the nasal mucosal barrier. Finally, the results of the immunisation studies showed that DNA-loaded nanoparticles elicit a fast and strong response, significantly more pronounced than that corresponding to the naked plasmid DNA for up to 6 weeks. Overall, these results suggest that these new nanoparticles have a potential as carriers for the delivery of DNA across the nasal mucosa.

Administration, Intranasal↗
PubMed2006

Distribution of L1-retroposons on the giant sex chromosomes of Microtus cabrerae (Arvicolidae, Rodentia): functional and evolutionary implications.

Long interspersed nuclear elements (L1 or LINE-1) are the most abundant and active retroposons in the mammalian genome. Traditionally, the bulk of L1 sequences have been explained by the 'selfish DNA' hypothesis; however, recently it has been also argued that L1s could play an important role in genome and gene organizations. The non-random chromosomal distribution of these retroelements is a striking feature considered to reflect this functionality. In the present study we have cloned and analyzed three different L1 fragments from the genome of the rodent Microtus cabrerae. In addition, we have examined the chromosomal distribution of this L1 in several species of Microtus, a very interesting group owing to the presence in some species of enlarged ('giant') sex chromosomes. Interestingly, in all species analyzed, L1-retroposons have preferentially accumulated on both the giant- and the normal-sized sex chromosomes compared with the autosomes. Also we have demonstrated that L1-retroposons are not similarly distributed among the heterochromatic blocks of the giant sex chromosomes in M. cabrerae and M. agrestis, which suggest that L1 retroposition and amplification over the sex heterochromatin have been different and independent processes in each species. Finally, we proposed that the main factors responsible for the L1 distribution on the mammalian sex chromosomes are the heterochromatic nature of the Y chromosome and the possible role of L1 sequences during the X-inactivation process.

Animals↗
PubMed2006

Advantages of real-time PCR assay for diagnosis and monitoring of canine leishmaniosis.

The aim of the present study is to highlight the advantages of real-time quantitative PCR intended to aid in the diagnosis and monitoring of canine leishmaniosis. Diagnosis of canine leishmaniosis is extremely challenging, especially in endemic areas, due to the diverse and non-specific clinical manifestations, and due to the high seroprevalence rate in sub-clinical dogs. Veterinarian clinicians are usually confronted with cases that are compatible with the disease, and with several diagnostic tests, sometimes with contradictory results. We have developed a new TaqMan assay, targeting the kinetoplast, applied to 44 samples of bone marrow aspirate or peripheral blood. The dynamic range of detection of Leishmania DNA was established in 7 logs and the limit of detection is 0.001 parasites in the PCR reaction. At the time of diagnosis parasitemia ranges from less than 1 to 10(7)parasites/ml. The ability to quantify the parasite burden allowed: (i) to elucidate the status of positive dogs by conventional PCR, although larger studies are necessary to clarify the dividing line between infection and disease, (ii) to estimate the kinetics of the parasite load and the different response to the treatment in a follow-up and (iii) to validate blood as less invasive sample for qPCR. The continuous data provided by real-time qPCR could solve the dilemma for the clinician managing cases of canine leishmaniosis by differentiating between Leishmania-infected dogs or dogs with active disease of leishmaniosis.

Animals↗
PubMed2006

Characterization of the porcine acyl-CoA synthetase long-chain 4 gene and its association with growth and meat quality traits.

Summary Long-chain acyl-CoA synthetase (ACSL) catalyses the formation of long-chain acyl-CoA from fatty acid, ATP and CoA, activating fatty acids for subsequent reactions. Long-chain acyl-CoA synthetase thus plays an essential role in both lipid biosynthesis and fatty acid degradation. The ACSL4 gene was evaluated as a positional candidate gene for the quantitative trait loci (QTL) located between SW2456 and SW1943 on chromosome X. We have sequenced 4906 bp of the pig ACSL4 mRNA. Sequence analysis allowed us to identify 10 polymorphisms located in the 3'-UTR region and to elucidate two ACSL4 haplotypes. Furthermore, a QTL and an association study between polymorphisms of the ACSL4 gene and traits of interest were carried out in an Iberian x Landrace cross. We report QTL that have not been previously identified, and we describe an association of the ACSL4 polymorphisms with growth and percentage of oleic fatty acid. Finally, we have determined allelic frequencies in 140 pigs belonging to the Iberian, Landrace, Large White, Meishan, Pietrain, Duroc, Vietnamese, Peccary and Babirusa populations.

Animals↗
PubMed2006

Polymorphisms of the porcine dopamine beta-hydroxylase gene and their relation to reproduction and piglet survivability in an Iberian x Meishan F2 intercross.

The goals of this study were to sequence and physically map the porcine dopaminebeta-hydroxylase (DBH) gene, as well as to perform an association study between polymorphisms of this gene and the reproductive performance and piglet survivability of F(2) pigs from an Iberian x Meishan cross. The porcine DBH gene was positioned by RH mapping near the telomere of chromosome 1q2.13, close to markers SSC10D08 and SW1301. Sequencing of DBH cDNAs from 10 pigs revealed the existence of six nucleotide polymorphisms, two of which led to non-synonymous amino acid substitutions within exon 3 at positions 463A>G and 616A>G that corresponded to Thr155Ala and Lys206Glu respectively. Three haplotypes segregated in an Iberian x Meishan population: DBH(X) (A(436)-A(616)), DBH(Y) (A(436)-G(616)) and DBH(Z) (G(436)-G(616)). The DBH haplotypes significantly affected rectal temperatures 1 h after birth (P = 0.002) and have a suggestive effect on the time to first colostrum intake (P = 0.019) and on birth weight (P = 0.019).

Animals↗
PubMed2006

Characterization of the porcine FABP5 gene and its association with the FAT1 QTL in an Iberian by Landrace cross.

We have characterized and mapped the porcine fatty acid binding protein 5, epidermal (FABP5) gene. According to linkage and RH mapping, this gene is located close to the FABP4 (fatty acid binding protein 4, adipocyte) gene on swine chromosome 4. We resequenced 4.7 kb of the FABP5 gene in the parental population of an Iberian x Landrace cross (IBMAP), identifying seven SNPs arranged in two distinct FABP5 haplotypes. QTL and association analyses in the IBMAP population showed that this gene is strongly associated with fat deposition. QTL and haplotype analysis revealed that both FABP4 and FABP5 (clustered in mammals) are major candidate genes for the FAT1 QTL; the most likely position for the FAT1 QTL is between these two genes. Finally, our results suggest the presence of more than one QTL affecting fatness traits on porcine chromosome 4.

Animals↗
PubMed2006

[Application of European Model of Quality in Oncology].

OBJECTIVES: To assess a Medical Oncology Service using a healthcare setting version of the European Foundation for Quality Management (EFQM). To use this tool as training, an opportunity for participation and the base for checking the strategic planning. MATERIAL AND METHODS: We use the EFQM Model adapted to healthcare centers EFQM as the evaluation instrument. It maintains scores and weights, only modifying vocabulary and simplifying that not relevant to the healthcare setting. Exercise was done with the "proform" system. Its advantage is that it uses standard formulas combined with open areas for discussion and presentation of ideas. It uses group sessions for agreement. STUDY PERIOD: 2001 Management. Evaluation was performed in the second term of 2002. RESULTS: 58 strengths and 37 areas of improvement were identified. These elements were used to create a strategic document, which served as the basis for future improvement. The score reached was used as an internal reference to monitor service quality evolution. CONCLUSIONS: The EFQM model is applicable in a Medical Oncology Service, although it would be desirable to have standardized quality indicators that permit a more objective and specific evaluation.

Europe↗
PubMed2006

Adipocyte fatty-acid binding protein is closely associated to the porcine FAT1 locus on chromosome 4.

We identified 22 polymorphisms in the adipocyte fatty-acid binding protein (FABP4) gene, a strong positional candidate gene for the FAT1 locus in porcine chromosome 4. The most informative polymorphism, an insertion/deletion in intron 1, together with a single nucleotide polymorphism in intron 3, was genotyped in a cross between Iberian and Landrace pigs. After performing QTL, single marker, and haplotype analyses, we showed that there were at least 2 quantitative trait genes in the FAT1 region and that the FABP4 polymorphism was tightly associated to fatness. A comparison of allelic frequencies in a panel of pig breeds suggested that the Del2634C polymorphism was under indirect selection. We also showed that FABP4 is tightly associated to fatness but not growth. Furthermore, a haplotype analysis suggests that there is genetic heterogeneity at the FAT1 locus within the Landrace breed.

Animals↗
PubMed2006

High amino acid variation in the intracellular domain of the pig prolactin receptor (PRLR) and its relation to ovulation rate and piglet survival traits.

Two polymorphisms of the porcine prolactin receptor (PRLR) gene were previously related to litter size by several authors; however, the magnitude and direction of such effects varied depending on the population analyzed. We have sequenced the complete coding region of the porcine PRLR gene and found 6 nonconservative SNP: C1217T (Leu/Pro406), C1283A (Asp/Ala428), G1439A (Lys/Arg480), T1528A (Met/Leu510), G1600A (Gly/Ser534), and G1789A (Gly/Ser597), within exon 10 of the gene, which encodes the entire intracytoplasmic domain of the protein. Eight haplotypes were found and were segregating at different frequencies in 6 porcine breeds. The effects of each individual SNP and haplotype were evaluated in an Iberian x Meishan F2 population using a univariate mixed-inheritance animal model. Significant effects on the number of corpora lutea were found for PRLR haplotypes (P < 0.012), confirming the previously reported associations of PRLR in this process and highlighting the importance of performing analysis of haplotypes rather than of individual SNP. Suggestive effects or tendencies were found for heart rate at birth (P < 0.10), rectal temperature (P < 0.05), and oxygen saturation (P < 0.10) 1 h after birth, and time to first suckle (P < 0.10). We found greater than expected levels of amino acid variability within the intracellular domain of the porcine PRLR, which have been associated with differences in the number of corpus lutea of sows and the preweaning survivability of piglets.

Amino Acid Sequence↗
PubMed2005

Prediction of temperature and thermal inertia effect in the maturation stage and stockpiling of a large composting mass.

A macroscopic non-steady state energy balance was developed and solved for a composting pile of source-selected organic fraction of municipal solid waste during the maturation stage (13,500 kg of compost). Simulated temperature profiles correlated well with temperature experimental data (ranging from 50 to 70 degrees C) obtained during the maturation process for more than 50 days at full scale. Thermal inertia effect usually found in composting plants and associated to the stockpiling of large composting masses could be predicted by means of this simplified energy balance, which takes into account terms of convective, conductive and radiation heat dissipation. Heat losses in a large composting mass are not significant due to the similar temperatures found at the surroundings and at the surface of the pile (ranging from 15 to 40 degrees C). In contrast, thermophilic temperature in the core of the pile was maintained during the whole maturation process. Heat generation was estimated with the static respiration index, a parameter that is typically used to monitor the biological activity and stability of composting processes. In this study, the static respiration index is presented as a parameter to estimate the metabolic heat that can be generated according to the biodegradable organic matter content of a compost sample, which can be useful in predicting the temperature of the composting process.

Biodegradation, Environmental↗
PubMed2005

Serotypes, virulence genes and intimin types of verotoxin-producing Escherichia coli and enteropathogenic E. coli isolated from healthy dairy goats in Spain.

Faecal samples from 222 healthy dairy goats on 12 farms in Spain, as well as bulk tank milk samples of these farms, were screened for the presence of verotoxin-producing Escherichia coli (VTEC) and enteropathogenic E. coli (EPEC). VTEC and EPEC were isolated in 47.7 and 7.7% of the animals, respectively. VTEC were isolated more frequently from adults and replacement animals than from goat kids. In contrast, EPEC were detected more frequently from goat kids than from replacement animals and adults. VTEC or EPEC strains were not detected in the bulk tank milk samples. Although a selective enrichment protocol was used, the serotype O157:H7 was not detected. The most frequent serotypes among the 106 VTEC strains isolated from goats were O5:H-, O76:H19, O126:H8, O146:H21, ONT:H- and ONT:H21. None VTEC strain was eae-positive. The absence of the eae gene in the VTEC strains could indicate that these strains are less virulent for humans that the classical eae-positive enterohaemorrhagic E. coli types. However, 16% of VTEC strains isolated from healthy goats belonged to serotypes associated with haemolytic uraemic syndrome in humans. The ehxA gene was detected in 84.9 and 52.9% of the VTEC and EPEC from goats, respectively. The beta1, theta/gamma2 and zeta were the most frequent intimin types among the 17 EPEC strains studied and the most prevalent serotypes of these strains were O156:H25 and O177:H11. Our data show that in Spain healthy goats are an important reservoir of VTEC and EPEC, and a potential source of infection for humans.

Adhesins, Bacterial↗
PubMed2005

PLA-PEG particles as nasal protein carriers: the influence of the particle size.

Previous studies have shown that PLA-PEG nanoparticles (NP) are able to enhance the transport of the encapsulated model protein, tetanus toxoid (TT), across the rat nasal mucosa. The aim of this work was to study if the size of PLA-PEG particles affects the nasal transport of the encapsulated protein and, also, the potential contribution of blank nanoparticles to the transport of the free protein. To achieve this purpose, 125I-TT was encapsulated into PLA-PEG particles of different sizes (200 nm, 1.5, 5 and 10 microm) prepared by the water-in-oil-in-water solvent evaporation technique. Firstly, in order to investigate the carrier role of the particles, two series of either conscious or anaesthetized rats were nasally treated with 125I-TT-loaded NP, free 125I-TT, and a physical mixture of blank NP and free 125I-TT. Secondly, the influence of the particle size on the nasal transport of TT encapsulated into PLA-PEG particles was evaluated in conscious rats. The amount of radioactivity recovered in the blood compartment, lymph nodes and other relevant tissues was monitored for up to 24h. Finally, the nasal bioavailability of 125I-TT-loaded PLA-PEG NP was calculated. The results indicated that the use of anaesthesia enhances the transport of 125I-TT and that the physical presence of PLA-PEG NP does not affect the transport of the toxoid. In contrast, when TT was encapsulated into the particles its transport across the nasal mucosa of conscious rats was significantly enhanced. Furthermore, the efficacy of this transport was related to the particle size, reaching the most important transport for the smallest particle size. The intensity of this transport was also illustrated by the high nasal bioavailability of TT encapsulated into nanoparticles (200 nm) (F = 70-80%). These results led us to conclude that PLA-PEG NP can be accepted as nasal protein carriers for nasal administration.

Administration, Intranasal↗
PubMed2005

Prevention of hyperacute rejection in a model of orthotopic liver xenotransplantation from pig to baboon using polytransgenic pig livers (CD55, CD59, and H-transferase).

INTRODUCTION: The search for alternative sources for transplant organs leads us to the search for animals as an inexhaustible source of organs. The objective of this study was to analyze whether livers from polytransgenic pigs expressing the human complement regulatory proteins CD55 (hDAF), CD59, and alfa alpha1,2-fucosyltransferase (H-transferase), protected against hyperacute rejection after orthotopic liver xenotransplantation to a baboon and also to study pig liver function in a nonhuman primate. MATERIALS AND METHODS: Nine liver transplants from pig to baboon were divided into two groups: a control group (n = 4) of genetically unmodified pigs and an experimental group (n = 5) of pigs transgenic for CD55, CD59, and H-transferase as donors. All the donating piglets obtained through hysterectomy were maintained in specific pathogen-free conditions. The selection of transgenic pig donors followed demonstration of transgene expression using monoclonal antibodies (antiCD55, antiCD59) and immunohistological studies on liver biopsies. RESULTS: All animals in the control group developed hyperacute rejection with survival rates less than 16 hours without function of transplanted livers. In the experimental group none of the animals suffered hyperacute rejection. Survival in this group was between 13 and 24 hours. The livers were functional, producing bile and maintaining above 35% prothrombin activity. Only in one case was there primary dysfunction of the xenograft. CONCLUSION: Polytransgenic livers for complement regulatory proteins prevent hyperacute rejection when xenotransplanted into a baboon.

Acute Disease↗