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Biomedical subjects

E Ugarte

Publications and source records attributed to E Ugarte.

13 recordsLinked to original sources
PubMed2005

Genetic parameters of udder traits, somatic cell score, and milk yield in Latxa sheep.

Genetic parameters have been estimated in the Black-Face ecotype of the Latxa breed for udder type traits (udder depth and attachment and teat placement and size) at first or later lactations (considered as different traits), as well as for udder type traits, milk yield, and lactational somatic cell score, including all lactations. Genetic correlations between udder type traits at first or later lactations ranged from 0.85 and 0.95 suggesting that they are nearly identical traits. Udder type traits had moderate heritabilities. Milk yield was estimated to have a genetic correlation of 0.43 with udder depth, 0.10 with udder attachment, -0.25 with teat placement, and -0.10 with teat size, which were unfavorable in general. Genetic correlations of lactational somatic cell score were 0.10 with udder depth, -0.27 with udder attachment, -0.01 with teat placement, and 0.29 with teat size. Genetic correlations between lactational somatic cell score and udder type traits show that udders with good shape are less prone to subclinical mastitis.

Animals↗
PubMed1996

Crosslinking of double-stranded oligonucleotides containing O-methyl-substituted pyrophosphate groups to the HNF1 transcription factor in nuclear cell extract.

Probing of the HNF1 (hepatocyte nuclear factor I) DNA-binding region using a set of DNA duplexes containing pyrophosphate or O-methyl-substituted pyrophosphate internucleotide groups at different positions of the HNF1 recognition sequence was performed. The histidine-tagged HNF1/1-281 DNA binding domain and nuclear extract from rat liver were used. We showed that HNF1 from these species specifically binds to modified DNA duplexes. A correlation in binding affinity of both types of duplexes was detected. Crosslinking of the HNF1 DNA-binding domain and HNF1 in nuclear liver extract to DNA duplexes carrying O-methyl-substituted pyrophosphate groups was observed. The crosslinking efficiency of HNF1 in liver extract to substituted pyrophosphate-modified DNA duplex, containing a reactive internucleotide group between nucleotides G and T of the GT dinucleotide immediately 5' to the TAAT recognition sequence, amounts to 40% of the efficiency of non-covalent association. Nonspecific crosslinking of the reactive DNA duplexes to other components of nuclear extract was not observed. These results indicate that DNA duplexes carrying substituted pyrophosphate internucleotide groups can specifically bind and crosslink with DNA-binding proteins, especially transcription factors in crude preparations and could constitute a potential tool to control the expression of disease-causing genes.

Animals↗
PubMed1996

Genetic parameters and trends for milk production of blond-faced Latxa sheep using Bayesian analysis.

The genetic progress attained with the breeding scheme of the blond-faced Latxa dairy sheep in the Spanish Basque Country was assessed by a Bayesian approach based on the marginal posterior distributions of parameters achieved via Gibbs sampling. The data file included 49,056 milk yield records of 22,363 ewes. Normal distributions were assumed for EBV and fixed effects, and scaled inverted chi-square distributions were assumed for variance components or additive, permanent environment, and residual effects. Under vague priors for variance components, the posterior means (SD) for heritability and permanent environment coefficient for milk yield at 120 d were 0.22(0.01) and 0.20(0.01). An important effect on the milk yield (41.6% of the mean) was evident for a genetic group of imported rams. Selection was effective for sheep that were bred by AI and that had known parents. The robustness of results for effect of genetic group and genetic trends was validated using a mildly informative prior constructed from variance components estimated with the related black-faced Latxa breed.

Animals↗
PubMed1993

Ex vivo regulation of specific gene expression by nanomolar concentration of double-stranded dumbbell oligonucleotides.

Inhibition of specific transcriptional regulatory proteins is a new approach to control gene expression. Transcriptional activity of DNA-binding proteins can be inhibited by the use of double-stranded (ds) oligodeoxynucleotides that compete for the binding to their specific target sequences in promoters and enhancers. As a model, we used phosphodiester dumbbell oligonucleotides containing a binding site for the liver-enriched transcription factor HNF-1 (Hepatocyte Nuclear Factor 1). Binding affinity of HNF-1 to dumbbell oligonucleotides was the same as that to ds oligonucleotides, as determined by gel retardation assays. HNF-1 dumbbells specifically inhibited in vitro transcription driven by the albumin promoter by more than 90%. HNF-1-dependent activation of a CAT reporter plasmid was specifically inhibited when the HNF-1 dumbbell oligonucleotide was added at nM concentration to transiently transfected C33 cells. On the contrary, HNF-1 ds oligonucleotides, which displayed the same activity as the dumbbell oligonucleotides in the in vitro assays, were no more effective in the ex vivo experiments. These results might reflect the increased stability of the circular dumbbell oligonucleotides towards cellular nuclease degradation, as shown in vitro with nucleolytic enzymes. Dumbbell oligonucleotides containing unmodified phosphodiester bonds may efficiently compete for binding of specific transcription factors within cells, then providing a potential therapeutic tool to control disease-causing genes.

Albumins↗
PubMed1993

HTLV-I maternal transmission in Martinique, using serology and polymerase chain reaction.

We have investigated HTLV-I and HTLV-II infection in children born to HTLV-I-seropositive or indeterminate Western blot mothers in Martinique by using the polymerase chain reaction (PCR). Only HTLV-I and no HTLV-II-positive samples were found in this study. All the samples from HTLV-I-seropositive children and adults were PCR positive, whereas the four HIV-I-seropositive and Western blot HTLV-I-negative mothers and their eight children were all PCR negative. Therefore, PCR and serology were in complete agreement in these patients. However, two of the six mothers who were first indeterminate by Western blot, and who later became seronegative, were found positive by PCR. Of the 27 children (ages 2-12 years), born to HTLV-I-seropositive and PCR-positive mothers, 2 were seropositive and PCR positive, 5 were seronegative and PCR positive with 2 primer pairs in gag and pol, and 4 were seronegative and PCR positive with only 1 of the primer pairs. In contrast to an initial rate of transmission of 7% estimated by serology we found a rate of transmission of 28 to 41% (whether or not children who were positive with only one of the primer pairs were included). Thus, our study confirms that PCR is useful in detecting HTLV-I infection in children before seroconversion and underlines the potential lack of sensitivity of serology to detect contaminating HTLV-I blood units in endemic areas.

Base Sequence↗
PubMed1992

An alternative to DNA extraction for the diagnosis of Pneumocystis carinii pneumonia by polymerase chain reaction using a new oligonucleotide probe.

We have used new specific primers and probe in a polymerase chain reaction (PCR) followed by Southern blot assays to detect Pneumocystis carinii in human bronchoalveolar lavage samples obtained from HIV-infected patients with pulmonary symptoms. To facilitate the procedure we developed a filtration technique without DNA extraction yielding a high sensitivity (18/18 positive results). The high specificity of the technique was shown by testing immunosuppressed patients without P. carinii pneumonia.

Animals↗
PubMed1988

v-jun is a transcriptional activator, but not in all cell-lines.

The recently isolated v-jun oncogene encodes a protein with sequence homology to the transcription factor AP1, as well as a similar DNA binding specificity. We show, by expressing v-jun in F9 embryocarcinoma cells, that v-jun is also a transcriptional activator. However, v-jun expression does not activate transcription in several other cell-lines, suggesting that cell-specific factors are required for v-jun activity.

Animals↗