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Biomedical subjects

E Blanco

Publications and source records attributed to E Blanco.

At least 37 records · Page 2Linked to original sources
PubMed2001

Apoptosis in chronic adult periodontitis analyzed by in situ DNA breaks, electron microscopy, and immunohistochemistry.

BACKGROUND: Apoptosis is an evolutionary form of physiological cell death. Previous studies suggest that apoptosis is involved in the pathogenesis of periodontal diseases. Therefore, we studied the apoptotic events in the gingival tissue of chronic adult periodontitis patients. METHODS: Gingival tissue biopsies from 22 patients with chronic adult periodontitis and from 11 healthy controls were obtained. Criteria for patient inclusion in the periodontitis group were a minimum of 14 natural teeth, excluding third molars, with at least 10 posterior teeth; 5 to 6 sites with probing depth > or = 5 mm; attachment loss > or = 3 mm; and extensive radiographic bone loss. The control group included healthy subjects with no prior history of periodontal disease. Apoptosis was determined using the terminal TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique; electron microscopic analysis; and expression of Caspase-3, Fas, FasL, Bcl-2, and p53 by immunohistochemistry. RESULTS: TUNEL-positive cells and cells exhibiting chromatin condensation by electron microscopy were observed in the inflammatory infiltrate of biopsies obtained from periodontitis patients. Most of the TUNEL-positive cells belonged to neutrophil cell populations as they were stained with anti-myeloperoxidase. Positive staining for active-caspase 3, Fas, FasL, and p53 was only observed in the inflammatory infiltrate from periodontitis biopsies, whereas Bcl-2 cells were present in both periodontitis patients and healthy controls. CONCLUSIONS: Our findings establish that apoptosis is induced in the periodontal tissue by host and microbial factors and support the hypothesis that apoptotic mechanisms could be implicated in the inflammatory process associated with gingival tissue destruction observed in adult periodontitis patients.

Adult↗
PubMed2000

Effect of dipyridamole and aspirin on the platelet-neutrophil interaction via the nitric oxide pathway.

This study was designed to determine the influence of the combination of aspirin and dipyridamole on the interaction in vitro between neutrophils and platelets through the nitric oxide (NO) pathway. Collagen-induced platelet aggregation (impedance method) was determined in platelet-rich plasma and in platelet-rich plasma+neutrophils, and cGMP (enzyme immunoanassay) and NO levels (electrochemical method, with a ISO-200 electrode) were also measured. The 50% inhibitory concentration (IC(50)) of aspirin was 139+/-11 microM in platelet-rich plasma, 367+/-21 microM in platelet-rich plasma+L-N(G)-nitro-arginine-methyl-ester (L-NAME), and 42+/-3 microM in platelet-rich plasma+L-arginine. The IC(50) for dipyridamole in platelet-rich plasma was not affected by L-NAME or L-arginine; the combination of aspirin with 20 microM dipyridamole (which has no effect per se) led to an IC(50) of 51+/-2 microM in platelet-rich plasma, 101+/-7 microM in platelet-rich plasma+L-NAME, and 13+/-2 microM in platelet-rich plasma+L-arginine. The cGMP levels showed the greatest increases in the aspirin plus dipyridamole group. Dipyridamole and aspirin increased the leukocyte production of NO: 50% increases were obtained at concentrations of 285+/-31 microM aspirin, 110+/-9 microM dipyridamole, and 16+/-2 microM aspirin+dipyridamole. Dipyridamole alone at a concentration of 20 microM had no significant effect on NO levels. We conclude that the combination of aspirin and dipyridamole significantly increases the antiplatelet effect of leukocytes, through an increase of NO, and that this effect is further evidence of the therapeutic benefits of this combination of drugs.

Adult↗
PubMed2000

GeneID in Drosophila.

GeneID is a program to predict genes in anonymous genomic sequences designed with a hierarchical structure. In the first step, splice sites, and start and stop codons are predicted and scored along the sequence using position weight matrices (PWMs). In the second step, exons are built from the sites. Exons are scored as the sum of the scores of the defining sites, plus the log-likelihood ratio of a Markov model for coding DNA. In the last step, from the set of predicted exons, the gene structure is assembled, maximizing the sum of the scores of the assembled exons. In this paper we describe the obtention of PWMs for sites, and the Markov model of coding DNA in Drosophila melanogaster. We also compare other models of coding DNA with the Markov model. Finally, we present and discuss the results obtained when GeneID is used to predict genes in the Adh region. These results show that the accuracy of GeneID predictions compares currently with that of other existing tools but that GeneID is likely to be more efficient in terms of speed and memory usage.

Alcohol Dehydrogenase↗
PubMed2000

Interspecies major histocompatibility complex-restricted Th cell epitope on foot-and-mouth disease virus capsid protein VP4.

T-cell epitopes within viral polypeptide VP4 of the capsid protein of foot-and-mouth disease virus were analyzed using 15-mer peptides and peripheral blood mononuclear cells (PBMC) from vaccinated outbred pigs. An immunodominant region between VP4 residues 16 and 35 was identified, with peptide residues 20 to 34 (VP4-0) and 21 to 35 (VP4-5) particularly immunostimulatory for PBMC from all of the vaccinated pigs. CD25 upregulation on peptide-stimulated CD4(+) CD8(+) cells-dominated by Th memory cells in the pig-and inhibition using anti-major histocompatibility complex class II monoclonal antibodies indicated recognition by Th lymphocytes. VP4-0 immunogenicity was retained in a tandem peptide with the VP1 residue 137 to 156 sequential B-cell epitope. This B-cell site also retained immunogenicity, but evidence is presented that specific antibody induction in vitro required both this and the T-cell site. Heterotypic recognition of the residue 20 to 35 region was also noted. Consequently, the VP4 residue 20 to 35 region is a promiscuous, immunodominant and heterotypic T-cell antigenic site for pigs that is capable of providing help for a B-cell epitope when in tandem, thus extending the possible immunogenic repertoire of peptide vaccines.

Amino Acid Sequence↗
PubMed2000

[Focal fatty liver lesions: infrequent ultrasonographic presentation].

We present case of focal fatty liver lesions. Echography images revealed multiple hyperechogenic lesions similar to those observed in metastatic disease. Aspiration was negative and diagnosis was based on the results of liver biopsy alone, carried out during laparoscopy. The difficulty of determining the etiology of this type of lesión by echography is discussed.

Fatty Liver↗
PubMed1999

Recombinant viruses expressing the foot-and-mouth disease virus capsid precursor polypeptide (P1) induce cellular but not humoral antiviral immunity and partial protection in pigs.

The importance of the induction of virus neutralizing antibodies to provide protection against foot-and-mouth disease virus (FMDV) infection is well established. However, recent studies with recombinant adenovirus expressing the precursor polypeptide of the viral capsid (P1) indicate that cattle inoculated with this recombinant vector developed partial protection against FMDV infection, in the absence of a detectable specific humoral response. Other viral vectors have been widely used to induce protective immunity against many pathogens, and it has been reported that the use of different vectors for priming and boosting injections can provide a synergistic effect on this response. In this work, we determined the immunogenicity of two recombinant viruses (adenovirus and vaccinia) expressing P1-FMDV, administered either individually or sequentially, and the protection that they induced against FMDV challenge in pigs. A double immunization with the adeno-P1 virus was the most effective strategy at inducing protective immunity. In contrast to previous reports, the use of two different vectors for priming and boosting did not show a synergistic effect on the protection induced against FMD. Interestingly, immunized pigs developed FMDV-specific T cell responses but not detectable antibodies. Thus, the protection observed was likely to be mediated by a cellular immune response.

Animals↗
PubMed1999

Immunohistochemical evidence of the presence of aromatase P450 in the rat hypophysis.

In order to analyze whether aromatase is present in the hypophysis of adult rats, we have performed an immunohistochemical study in young adult male and female rats. Our study has revealed that the hypophysis of adult rats contains aromatase, although marked differences are found between the sexes. The hypophyses of male rats have cells immunoreactive for the enzyme, 34.40% of these hypophyseal cells showing reaction. By contrast, cells from female rats show very little reaction, only 0.84% of them being reactive. No significant differences in the percentage of immunoreactive cells between one phase and another are observed during the estrous cycle. Our results point to the immunohistochemical expression of aromatase in the hypophysis of adult rats and at the same time suggest that its expression is sex-dependent. The enzyme may therefore be involved in the regulation of adenohypophyseal cytology by androgens.

Amino Acid Sequence↗
PubMed1999

Medicinal and veterinary plants of El Caurel (Galicia, northwest Spain).

A study of the medicinal and veterinary plants popularly used in El Caurel region (Lugo province, northwest Spain) and their relationships is reported. We obtained data for 85 species belonging to 31 families of vascular plants. Their vernacular names, properties, preparations, mode and popular uses are presented.

Animals↗
PubMed1999

Synthetic peptide vaccines: foot-and-mouth disease virus as a model.

Foot-and-mouth disease virus (FMDV) has been one of the pioneering viral systems in the development of synthetic peptides as vaccines. Protection against FMDV infection is associated with the induction of neutralising antibodies. Therefore, attempts have been made to identify peptides capable of eliciting protective humoral responses. Peptides based on a continuous, immunodominant B cell site on the capsid protein VP1 have been shown to confer limited protection in natural hosts. This probably reflects the difficulties in reproducing the immunogenicity of an entire viral particle by using a much simpler synthetic antigen, due to: (i) the polymorphism of the class II MHC; (ii) the adequate presentation to the immune system of the peptides, and (iii) the difficulties of achieving protection against a highly variable RNA virus, which may favour selection of virus antigenic variants. The improvement of FMD peptide vaccines, and the development of in vitro alternatives to in vivo immunogenic assays require further understanding of the immune mechanisms leading to protection against this important animal virus disease.

Animals↗
PubMed1998

A RT-PCR assay for the differential diagnosis of vesicular viral diseases of swine.

A RT-PCR assay based on specific amplification of RNA sequences from each of the etiological agents of three important vesicular diseases that affect swine, foot-and-mouth disease virus (FMDV), swine vesicular disease virus (SVDV), and vesicular stomatitis virus (VSV), was developed. Genotype-specific primers that amplified DNA fragments of differential size from SVDV 3D gene or VSV L gene were selected with the aid of a computer program. Experimental testing of the primers predicted as SVDV-specific identified a primer pair, SA2/SS4, that rendered a specific product from SVDV RNAs, but did not amplify RNA from either FMDV or coxsackie B5 virus (CV-B5), a highly related picornavirus. Primers SA2/SS4 were used in combination with primers 3D2/3D1, which amplify a product of different size on FMDV 3D gene (Rodriguez et al., 1992). This combined RT-PCR reaction allowed a sensitive and specific differential detection of FMDV and SVDV RNAs in a single tube, by means of the analysis of the amplified products in agarose gels. The results obtained were similar when RNA extracted from viral stocks or plastic wells coated with either viral supernatants or extracts from lesions of infected animals, were used as starting material in the reactions. Using a similar approach, VSV serotype-specific primers IA/IS and NA/NS were selected for the specific amplification of VSV-Indiana and VSV-New Jersey RNAs, respectively. The combined use of SVDV, FMDV and VSV specific primers in a single reaction resulted in a genotype-specific amplification of each of the viral RNAs. Thus, differential diagnosis of FMDV from SVDV and/or VSV can be carried out in a single RT-PCR reaction, using a rapid and simplified methodology.

Animals↗
PubMed1998

Seventy-two hour epirubicin infusion plus quinidine in unresectable and metastatic adenocarcinoma of the pancreas: a phase II trial.

Twenty-two previously untreated patients who had unresectable and metastatic pancreatic cancer were treated in a prospective phase II trial with high-dose continuous infusion epirubicin (45 mg/m2 once every 24 hours continuous infusion days 4 through 6) plus quinidine (495 mg once every 24 hours on days 1-6). There were no objective responses (0 of 18 evaluable patients). Subjective responses were achieved in 2 of 21 evaluable patients (9%), all of whom had good performance status (Eastern Cooperative Oncology Group: 0-1). Median survival was 5.7 months for the overall population. Two patients who exhibited symptomatic improvement achieved responses lasting 7 and 13 months, respectively. Toxicity was generally mild and tolerable. Little benefit regarding survival and quality of life was observed with the use of this regimen. The role in chemoresistance of mdrl, p53, and the mismatch repair system was examined.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Variations in blood levels of aminoglycosides related to in vitro anticoagulant usage.

Aminoglycosides (AMG) remain an important therapeutic modality for the treatment of gram-negative infections. Adequate AMG levels have been associated with a lower risk of toxicity. Because AMG levels cannot be predicted with confidence, drug concentrations need to be measured. The authors studied the effect of different anticoagulants on AMG concentrations, which were determined by enzyme immunoanalysis. Blood samples from patients treated with AMG were obtained, and were immediately distributed in five tubes containing EDTA, sodium-citrate, or heparin at concentrations of 5 and 50 U/ml; one serum aliquot was kept as a control. All AMG determinations were performed by the enzyme multiplied immunoassay technique with Cobas-Mira equipment. The average coefficient of variations was < 3%. All samples were run the same day. Analysis of variance for repeated measures was used. Twenty-four patients (21 male and 6 female) with a mean age of 50 years (95% confidence interval = 43 to 58) and mean serum creatinine concentrations of 0.87 to 0.29 +/- Standard Deviation received 89% gentamicin and 11% tobramycin. Peak levels of AMG obtained from plasma collected with sodium citrate or heparin were significantly lower (p < 0.001) than in serum or plasma collected with EDTA. The higher the level of AMG in serum, the greater the discrepancies between drug concentrations measured with different anticoagulants. The anticoagulant used was of critical importance in determining AMG blood levels, which were underestimated when citrate or heparin were present.

Adult↗
PubMed1998

RT-PCR in foot-and-mouth disease diagnosis.

A RT-PCR assay for the specific detection of RNA sequences from foot-and-mouth disease virus (FMDV) has been developed. The procedure permits also the detection of sequences that correlate with established FMDV serotypes. A computer program that allows selection of genotype-specific primers for RT-PCR amplification was used for the identification of FMDV specific sequences for PCR amplification on RNA replicase (3D) gene regions. Specific, rapid and highly sensitive detection was achieved for a wide collection of RNA samples from FMDV types C, A and O, either purified from tissue culture or extracted from lesions of infected animals. Similarly, serotype-specific primers were designed to amplify the carboxy-terminal end of the VP1 gene of FMDV types either C, A or O. The results of PCR amplification of different FMDV RNAs using type-specific primers are in agreement with the serological typing of the corresponding viruses. A combination of this approach with a simplified sample processing, carried out following direct adsorption of viral suspensions to microtiter plates, provides a rapid, reliable method of viral diagnosis.

Animals↗
PubMed1997

Effect of erythrocytes and prostacyclin production in the effect of fructose and sorbitol on platelet activation in human whole blood in vitro.

We analyzed the in vitro effects of sorbitol and fructose on platelet function. Sorbitol and fructose increased platelet aggregation induced with adenosine diphosphate (ADP) or collagen in whole blood, but had no effect in platelet-rich plasma. The concentration that increased basal aggregation by 50% with ADP as the inducer was 12.89 +/- 1.55 mmol/L for fructose, and 18.99 +/- 2.01 mmol/L for sorbitol. When collagen was the inducer, these concentrations were 15.02 +/- 0.98 mmol/L for fructose, and 12.94 +/- 1.57 mmol/L for sorbitol. Both sugars increased, in a concentration-dependent way, the proaggregatory effect of erythrocytes, and erythrocyte uptake of adenosine. Time to uptake of 50% adenosine was 2.1 +/- 0.3 min in control samples, 0.14 +/- 0.01 min in the presence of fructose, and 0.23 +/- 0.03 min with sorbitol. Both sugars reduced vascular prostacyclin synthesis, with 50% inhibitory concentrations of 26.48 +/- 1.97 mmol/L for fructose, and 39.53 +/- 2.81 mmol/L for sorbitol. Both sugars also increased arterial lipid peroxidation by 30% (sorbitol) and 23% (fructose). We conclude that these two sugars enhance platelet function and disrupt the thromboxane/prostacyclin ratio.

6-Ketoprostaglandin F1 alpha↗
PubMed1997

Coexistence of NADPH-diaphorase with tyrosine hydroxylase in hypothalamic magnocellular neurons of the rat.

The presence and distribution of NADPH-diaphorase (ND) neurons as well as tyrosine hydroxylase-immunoreactive (TH) neurons in the hypothalamus are well established. Previous studies have shown the coexistence of ND with neuroactive substances such as calbindin, somatostatin, vasopressin and oxytocin in neurons of this region of the brain. As the tópographical patterns of distribution of ND and TH coincide in many cases, the aim of this study was to determine the possible coexistence of both substances in the main hypothalamic magnocellular nuclei of the albino rat. Histochemical-immunocytochemical double labelling was employed on the same sections as well as a morphometric study. NADPH-diaphorase and tyrosine hydroxylase neurons were observed in all the nuclei under study (supraoptic, paraventricular and accessory nuclei), although most neurons showing the coexistence of both substances were mainly located in the supraoptic nucleus, isolated neurons with double labelling being found in the magnocellular parts of the paraventricular nucleus and in some of the accessory nuclei. Although both substances have previously been shown to be modified in hypothalamic neurons after osmotic stimuli, the range of functions of ND in the CNS is only beginning to be understood. Further studies are needed to elucidate the functional role that ND/TH neurons play in the nervous system.

Animals↗