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M Carballo

Publications and source records attributed to M Carballo.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Asp-190-Tyr mutation in the rhodopsin gene in a Spanish family with autosomic dominant pigmentary retinosis].

Mutations in the rhodopsin cause of retinitis pigmentosa autosomal dominant (ADRP). We report a large family affected with ADRP. Analysis by denaturant gradient gel electrophoresis and direct DNA sequence detected an heterozygous G to T transversion in the exon 3 of the rhodopsin gene. This mutation damages a restriction site for Taq I enzyme and produces the change Asp-190-Tyr in rhodopsin. All carriers of the mutation show a regional RP phenotype. This mutation is responsible for the disease in this family.

Adolescent↗
PubMed2000

The use of alternative systems for the ecotoxicological screening of complex mixtures on fish populations.

This paper presents the results of the use of alternative systems in a screening study of four complex mixtures. The following tests were performed: in vitro induction of micronuclei in a rainbow trout-derived cell line by flow cytometry, and hatching percentage, time of hatching and teratogenic alterations on the embryolarval development on medaka fish eggs. The results obtained with the proposed tests in this study allows an increase in the information level in a short period of time (2 weeks), using very low sample volumes (< 100 ml). Inclusion of chronic and specific effects (genotoxicity and teratogenicity) allows the selection of the most sensitive endpoint to increase security factors in the ecotoxicological assessment of complex mixtures, so that detailed studies can be focused only on those samples which require further research.

Animals↗
PubMed2000

Ecotoxicological evaluation of pig slurry.

Swine sewage could be source of nutrients and pollutants. This work estimates the environmental risk in nine samples from different farm treatment systems based on the evaluation of their effects in Daphnia magna acute test, and on the assessment of Cu, Zn and ammonia as main contributors. NH3 and Cu were responsible for LC50 results (1-5% of dilution). Organic compounds were quantified through several extraction methods (SPMDs, SPE and solvent extraction). A more exhaustive extraction was performed in an additional sample, which showed indole and phenol recoveries much higher than the previous ones. This method also includes PCBs (430 ppb) and fatty acids (approximately =150 ppm) quantification.

Ammonia↗
PubMed2000

Pharyngeal bot flies in Cervus elaphus in central Spain: prevalence and population dynamics.

The prevalence and intensity of infestations by bot flies Pharyngomyia picta and Cephenemyia auribarbis in red deer (Cervus elaphus) from Quintos de Mora (Toledo, Spain) were determined over a 1-yr period. Bots were present all year. No clear correlations were found between age or sex of the host and parasitization levels (prevalence and intensity). Considerable variation was found in prevalence and intensity, with larger values from December to March. Cephenemyia auribarbis was restricted from November to March, with maximum numbers of L-3 in February. Pharyngomyia picta showed a more complex profile with 2 peaks (March and August), indicating 2 generations per year.

Age Factors↗
PubMed2000

Homozygous and heterozygous gly-188-Arg mutation of the rhodopsin gene in a family with autosomal dominant retinitis pigmentosa.

Autosomal dominant retinitis pigmentosa (adRP) may be caused by point mutations in the rhodopsin gene in up to 20% of Spanish families. Most of the rhodopsin mutations causing adRP have been reported in the heterozygous state. We describe a patient with adRP who is homozygous for a missense mutation at codon 188 in the second intradiscal domain of rhodopsin. All her sons are heterozygous for the mutation and show an RP phenotype suggesting complete penetrance for this mutation. The homozygous carrier of the mutation Gly-188-Arg in the rhodopsin gene showed a later subjective onset of symptoms than the heterozygotes, suggesting that the photoreceptor degeneration induced by the mutation is not dramatically influenced by mutant allele dosage.

Adult↗
PubMed2000

Prevalence of 2314delG mutation in Spanish patients with Usher syndrome type II (USH2).

The Usher syndrome (USH) is a group of autosomal recessive diseases characterized by congenital sensorineural hearing loss and retinitis pigmentosa. Three clinically distinct forms of Usher syndrome have so far been recognized and can be distinguished from one another by assessing auditory and vestibular function. Usher syndrome type II (USH2) patients have congenital moderate-to-severe nonprogressive hearing loss, retinitis pigmentosa, and normal vestibular function. Genetic linkage studies have revealed genetic heterogeneity among the three types of USH, with the majority of USH2 families showing linkage to the USH2A locus in 1q41. The USH2A gene (MIM 276901) has been identified: three mutations, 2314delG, 2913delG, and 4353-54delC, were initially reported in USH2A patients, the most frequent of which is the 2314delG mutation. It has been reported that this mutation can give rise to typical and atypical USH2 phenotypes. USH2 cases represent 62% of all USH cases in the Spanish population, and 95% of these cases have provided evidence of linkage to the USH2A locus. In the present study, the three reported mutations were analyzed in 59 Spanish families with a diagnosis of USH type II. The 2314delG was the only mutation identified in our population: it was detected in 25% of families and 16% of USH2 chromosomes analyzed. This study attempts to estimate the prevalence of this common mutation in a homogeneous Spanish population.

Alleles↗
PubMed1999

Oxidative stress triggers STAT3 tyrosine phosphorylation and nuclear translocation in human lymphocytes.

Oxidizing agents are powerful activators of factors responsible for the transcriptional activation of cytokine-encoding genes involved in tissue injury. In this study we show evidence that STAT3 is a transcription factor whose activity is modulated by H2O2 in human lymphocytes, in which endogenous catalase had previously been inhibited. H2O2-induced nuclear translocation of STAT3 to form sequence-specific DNA-bound complexes was evidenced by immunoblotting of nuclear fractions and electrophoretic mobility shift assays, and vanadate was found to strongly synergize with H2O2. Moreover, anti-STAT3 antibodies specifically precipitated a protein of 92 kDa that becomes phosphorylated on tyrosine upon lymphocyte treatment with H2O2. Phenylarsine oxide, a tyrosine phosphatase inhibitor, and genistein, a tyrosine kinase inhibitor, cooperated and cancelled, respectively, the H2O2-promoted STAT3 nuclear translocation. Evidence is also presented, using Fe2+/Cu2+ ions, that.OH generated from H2O2 through Fenton reactions could be a candidate oxygen reactive species to directly activate STAT3. Present data suggest that H2O2 and vanadate are likely to inhibit the activity of intracellular tyrosine phosphatase(s), leading to enhanced STAT3 tyrosine phosphorylation and hence its translocation to the nucleus. These results demonstrate that the DNA binding activity of STAT3 can be modulated by oxidizing agents and provide a framework to understand the effects of oxidative stress on the JAK-STAT signaling pathway.

Arsenicals↗
PubMed1999

Characterization of calcineurin in human neutrophils. Inhibitory effect of hydrogen peroxide on its enzyme activity and on NF-kappaB DNA binding.

We describe here a specific calcineurin activity in neutrophil lysates, which is dependent on Ca2+, inhibited by trifluoroperazine, and insensitive to okadaic acid. Immunoblotting experiments using a specific antiserum recognized both the A and B chains of calcineurin. Neutrophils treated with cyclosporin A or FK 506 showed a dose-dependent inhibition of calcineurin activity. The effect of oxidant compounds on calcineurin activity was also investigated. Neutrophils treated with hydrogen peroxide (H2O2), where catalase was inhibited with aminotriazole, exhibited a specific inhibition of calcineurin activity. However, the addition of reducing agents to neutrophil extracts partially reversed the inhibition caused by H2O2. A similar inhibitory effect of H2O2 on calcineurin activity was observed to occur in isolated lymphocytes. This is the first demonstration that redox agents modulate calcineurin activity in a cellular system. In addition, electrophoretic mobility shift assays revealed that lipopolysaccharide-induced activation of NF-kappaB in human neutrophils is inhibited by cell pretreatment with H2O2 in a dose-dependent manner. These data indicate that calcineurin activity regulates the functional activity of lipopolysaccharide-induced NF-kappaB/Rel proteins in human neutrophils. These data indicate a role of peroxides in the modulation of calcineurin activity and that the H2O2-dependent NF-kappaB inactivation in neutrophils occurs in concert with inhibition of calcineurin.

Calcineurin↗
PubMed1999

Phenylarsine oxide increases intracellular calcium mobility and inhibits Ca(2+)-dependent ATPase activity in thymocytes.

A rise in intracellular Ca(2+) levels has been implicated as a regulatory signal for the initiation of lymphocyte proliferation. In the present study the mechanism underlying the elevation of [Ca(2+)] induced by phenylarsine oxide [PAO] was investigated in thymocytes. This agent inhibits HIV-1 replication and also NF-kappaB-mediated activation. It has been reported that the PAO-induced Ca(2+) elevation results from an enhanced plasma membrane calcium permeability in T cells. Here, we present biochemical evidence that the PAO-induced Ca(2+) increase was independent of external Ca(2+). Consistent with these facts, when [Ca(2+)](i) was depleted by prolonged incubation of the cells in Ca(2+)-free medium, PAO addition did not lead to [Ca(2+)](i) increase. These data indicate the involvement of intracellular organelles of thymocytes as the source of Ca(2+). Moreover, evidence is presented that PAO inhibited Ca(2+)-dependent ATPase activity from thymocytes and sarcoplasmic reticulum from skeletal muscle. This inhibition was dose-dependent, with a IC(50) of about 30 microM for both preparations of enzyme. The ability of PAO to inhibit Ca(2+)-dependent ATPase represents a novel mechanism of action for this drug. Present data suggest that the PAO-dependent [Ca(2+)](i) increase could be mainly the result of inhibition of Ca(2+)-dependent ATPase. In addition, we describe also a Ca(2+)-dependence for PAO effect on tyrosine phosphorylation.

Animals↗
PubMed1999

Serological markers and HLA-DQ2 haplotype among first-degree relatives of celiac patients. Catalonian Coeliac Disease Study Group.

Serologic markers, HLA-DQ2 haplotype, and clinical features suggestive of celiac disease were studied to assess their diagnostic value in a multicentric study to detect celiac disease in 675 first-degree relatives of 227 celiac probands. Serum IgA-class anti-endomysium and IgA-class anti-gliadin antibodies were positive in 5.8% and 1.9% of relatives, respectively. HLA-DQ2 haplotype was present in 64% of relatives, and the overall rate of celiac disease diagnosed by intestinal biopsy was 5.5%. The frequency of HLA-DQ2 in the celiac patients and controls was 93% and 18%, respectively. The most frequent clinical features--diarrhea, anemia, food intolerance, and growth retardation--were not present in one third of the celiac disease relatives. We conclude that the assessment of IgA-class anti-endomysium antibodies alone seems a reasonable approach for screening celiac disease in relatives and cannot be replaced by an accurate clinical anamnesis. HLA-DQ2 haplotype may identify the population with a high genetic susceptibility to celiac disease.

Adult↗
PubMed1999

[Corpus callosum agenesis and epileptic seizures].

INTRODUCTION: The corpus callosum is the major neopallial connection between the two cerebral hemispheres. The corpus callosum agenesis (CCA) is found in 14% of CNS malformations. The diagnosis is based on neuroimaging procedures (ultrasonography, CT, MRI). The CCA is usually associated with facial dysmorphia, developmental delay and epileptic seizures. Two casuistic are studied, one with necropsies material and another with CCA patients alive, on which CCA was frequently associated with other CNS malformations, in order to establish the circumstances in which the epileptic seizures have been observed. DEVELOPMENT: It is commonly admitted that the presenting signs or symptoms in individuals with CCA are due to concurrent brain abnormalities and that isolated CCA is essentially asymptomatic. The CCA is a common component in some malformative syndromes, frequent in another, and occasional in many of them. The CCA has been reported in many chromosomal aberrations and less frequently in inborn errors of metabolism and neurocutaneous diseases. In the casuistic studies of 73 patients alive, 25 (39%) have presented epileptic fits: in 24 of them the CCA was associated to another brain abnormalities; in 17 cases, the first seizures was recorded during the first year, in 6 cases between 1 and 3 years and in cases after 2 years: the type of epileptic seizures is variable: neonatal convulsions in 4 cases, infantile spasms in 5, unilateral fits in 3, and partial seizures in 1 case. In the necropsies casuistic with 26 CCA cases, 6 (23%) suffered epileptic fits, all with another malformations of the CNS; in 3 the onset of the seizures was during the newborn period, 2 had infantile spasms during the first years and 1 case generalized seizures during the second year. CONCLUSIONS: 1. Epileptic seizures were observed in 23%-39% of the CCA cases studied. 2. All cases with CCA, except for one, have also another brain abnormality. 3. In 70% of the cases, the onset of the fits takes place during the first year. 4. The type of seizures is variable with predominance of infantile spasms and unilateral seizures.

Agenesis of Corpus Callosum↗
PubMed1998

[Identification of 2 allelic mutations of the gene of the phosphodiesterase beta subunit in a Spanish family with recessive autosomic retinitis pigmentosa].

BACKGROUND: Retinitis pigmentosa (RP) is a group of inherited eye disorders that affect photoreceptor and pigment epithelial function. Mutations in different genes involved in the phototransduction process have been described in patients with autosomal recessive RP. PATIENTS AND METHODS: We examined the gene coding the beta subunit of the phosphodiesterase (PDEB) in a ARRP family with two affected sisters. SSCP (single stand conformational polymorphism) analysis of the coding region of the gene showed abnormal bands in two different exons. PCR products showing SSCP aberrant patterns were subsequently sequenced. RESULTS: The two affected sisters had inherited from their father a PDEB gene with a known mutation (Gln298X) and a rare variant and from their mother a PDEB gene with a new mutation: Asp600Asn. CONCLUSIONS: The nature of the mutations in the PDEB gene and their pattern of inheritance indicate that the lack of activity of the phosphodiesterase (PDE), a key enzyme in the visual phototransduction process, account for the RP phenotype in these patients.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1998

[The Pro347Leu mutation of the rhodopsin gene in a Spanish family with autosomal dominant pigmentary retinosis].

We present a Spanish family affected with autosomal dominant pigmentary retinosis in which we have identified the mutation responsible for the disease (Pro347Leu) within the rhodopsin (RHO) gene. Complete ophthalmological and electrophysiological studies were performed in 14 members of this family. The molecular study, performed by SSCP analysis of the 5 exon and the promotor region of the rhodopsin gene, direct sequentiation and restriction analysis with the enzyme Mspl, showed a C-->T change in the second base of 347 codon of RHO gene. This mutation predicts a change of proline by leucine at this position. Every patient with the mutation showed a phenotype of diffuse, early onset and severe pigmentary retinosis with a little intrafamiliar variation. The Pro347Leu mutation, that has been very frequently described among all the populations, has been identified as a cause of RP in an Spanish family.

Adolescent↗
PubMed1998

p53 transactivation of the HIV-1 long terminal repeat is blocked by PD 144795, a calcineurin-inhibitor with anti-HIV properties.

Previous reports have indicated that benzothiophenes exhibit broad anti-inflammatory properties and inhibit human immunodeficiency virus-type 1 (HIV-1) replication. We show that the immunosuppressant cyclosporin A (CsA) and benzothiophene-2-carboxamide, 5-methoxy-3-(1-methyl ethoxy)-1-oxide (PD 144795) block the induction of p53 and NF-kappaB binding to the HIV-1 long terminal repeat (LTR) by the T cell receptor activator phytohemagglutinin. CsA and PD 144795 also inhibit the induction by phytohemagglutinin of the transcription mediated by an HIV-1 LTR fragment containing the p53 and NF-kappaB sites. These effects of PD 144795 on HIV-1 transcription correlate with its ability to inhibit the phosphatase activity of calcineurin and are similar to those previously described for CsA. Moreover, a constitutive active form of calcineurin is able to induce expression from the HIV-1 LTR in a p53- and NF-kappaB-dependent manner and PD 144795 is able to block this induction. These results demonstrate that the DNA binding of p53 to the HIV-1 LTR can be modulated by calcineurin and provide a framework to understand the anti-HIV properties of benzothiophene derivatives.

Anti-HIV Agents↗