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Biomedical subjects

A Nieto

Publications and source records attributed to A Nieto.

At least 91 records · Page 5Linked to original sources
PubMed1998

Immunohistochemical localization of epidermal growth factor, transforming growth factor-alpha and growth factor-beta s in the caprine peri-implantation period.

Control over the action of steroid hormones in the uterus and conceptus during the initial period of gestation appears to be regulated locally by growth factors. This study involved immunohistochemical detection of epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha) and transforming growth factor-beta s (TGF-beta s), to determine their role in the caprine peri-implantation period. Epidermal growth factor was expressed in the luminal and glandular endometrial epithelium of goats on all days studied (Days 22 to 30 post coitum), but it was not detected in trophoblastic cells or in other embryonic structures. Between Days 22 and 30 post coitum, TGF-alpha was detected in the epithelial cells and superficial stroma of the uterus and in the trophoendodermic cells of the embryo. Transforming growth factor-beta s expression, observed in the endometrium, embryo and extraembryonic membranes on Day 22 post coitum, decreased by Day 24 post coitum and disappeared in the embryo by Day 30 post coitum, while remaining in the other structures. The presence of these growth factors during the peri-implantation period in the goat suggests their participation in proliferation and differentiation phenomena which occur during implantation and embryonic development.

Animals↗
PubMed1998

A mucosal IgA response, but no systemic antibody response, is evoked by intranasal immunisation of dogs with Echinococcus granulosus surface antigens iscoms.

The search for protective antigens of intestinal parasites is conditioned by the methodology used to induce a relevant local immune response against them. The present work describes the use of immuno stimulating complexes (iscoms) from tegumental antigens from protoscoleces (PSC) of the cestode Echinococcus granulosus as immunogens in dogs by the intranasal route. It also describes the evaluation of the immune response evoked at the antibody level (systemically and at a distant mucosal location) as well as at the level of antibody secreting cells in peripheral blood. Iscoms from both E. granulosus tegumental antigens and hen ovalbumin (OVA), given at 50 microg doses by intranasal route, evoked significant secretory IgA antibody responses detected in saliva. Specific IgA secreting cells in peripheral blood also increased 10-20-fold, although transiently, after primary and secondary stimulation, whereas specific IgG secreting cells in peripheral blood were only detected in some individuals after the second antigenic exposure. Generation of immune responses at a related mucosal site provides evidence of localised immunity. No significant increase in systemic antibody titers of either IgM, IgG or IgA isotype was detected in plasma as a result of the immunisation. This fact could reflect that the nasopharyngeal mucosal associated lymphoid tissue of dogs is more strictly compartmentalised than that of other mammals.

Adjuvants, Immunologic↗
PubMed1998

Molecular cloning of the cDNA and the promoter of the hamster uteroglobin/Clara cell 10-kDa gene (ug/cc10): tissue-specific and hormonal regulation.

Using the polymerase chain reaction on first-strand cDNAs from lung as well as on genomic DNA, we have cloned and sequenced both the cDNA and 1.5 kb of the promoter of the gene coding for hamster uteroglobin/Clara cell 10-kDa protein (UG/CC10), a secretory protein mainly synthesized in the pulmonary Clara cells. The amino acid sequence deduced from the cDNA indicated a preprotein of 96 residues, 19 of which corresponded to the signal peptide. The promoter region contained transcriptional regulatory elements conserved between species. Northern blot and S1 resistance assays detected high expression of ug/cc10 in lung but not at all in other tissues. Expression in lung was positively controlled by glucocorticoids and was also subjected to a biphasic developmental regulation after birth. In agreement with the tissue-specific expression observed in vivo, the hamster promoter preferentially directed the expression of a reporter gene in cells derived from Clara cells. The results indicated that the tissue-specific expression and the regulation of ug/cc10 varied considerably between species but all of them had a high expression in lung.

Amino Acid Sequence↗
PubMed1998

Fetal cardiotocography and acid-base status during cesarean section.

OBJECTIVE: To assess the fetal well-being during cesarean section, in relation to the previous fetal condition. DESIGN: Observational study. SETTING: University Hospital. PATIENTS PARTICIPANTS: 204 women undergoing cesarean section (203 intrapartum cesarean sections): 177 with general anesthesia and 27 with spinal anesthesia. MATERIAL AND METHODS: We compared the fetal heart records of the last 30 min before cesarean section (during the first stage of labor) with those during cesarean section. Scalp blood analysis 30 min before the beginning of anesthesia induction was compared with umbilical artery analysis at delivery. MAIN OUTCOME MEASURES: Cardiotocography. Acid-base analysis. Apgar scores. RESULTS: During cesarean section there was a reduction in uterine activity, an increase in silent tracings and a decrease in late decelerations. Umbilical artery pH was lower than scalp pH (7.23+/-0.06 vs 7.30+/-0.06). Oxygen saturation was also lower (14.43+/-8.58% vs 18.99+/-8.4%). The values of pCO2 and of base deficit were higher. During cesarean section low values of modified Fischer scores were associated with low pH values of umbilical artery and low Apgar scores. CONCLUSION: Silent tracings appearing during cesarean section usually do not indicate fetal distress. Poor intracesarean fetal heart tracings were associated with worse indicators of neonatal well-being. Although umbilical pH were lower than scalp values, when the correction described in the literature was applied, the difference was of little clinical relevance. It is concluded that anesthesic, pharmacological and surgical events have slight repercussion in fetal well being. However, in a few cases fetal heart monitoring during cesarean section could detect otherwise undiagnosed cases of transient acidemia or depression in the fetus.

Acid-Base Equilibrium↗
PubMed1998

Acoustic voice analysis in patients with essential tremor.

To quantify several acoustic features of the voice in patients with essential tremor (ET), 28 patients and 28 age- and sex-matched controls were studied. ET severity was assessed with the rating scale for tremor of Fahn, Tolosa, and Marín. The Computerized Speech Lab 4300 program (Kay Elemetrics) was used. Two-second samples of a sustained /a/ and a sentence were captured with a microphone and laryngograph equipment. Measures included fundamental frequency (F0), frequency perturbation (jitter, Koike algorithm), intensity perturbation (shimmer, Horii algorithm), and harmonic-to-noise ratio (H/N, Yumoto algorithm) of the vowel /a/, and the frequency and intensity variability of the sentence, phonational range, and dynamic range at the natural frequency, maximum phonational time, and s/z ratio. All subjects underwent indirect laryngoscopy and/or laryngeal fibroscopy. When compared with controls, ET patients showed higher jitter, lower H/N ratio (the last one only with laryngographic signal), of the vowel /a/, lower frequency variability in the microphonic signal, lower intensity variability in the laryngographic signal of the sentence, and significantly lower dynamic range at natural frequency of phonation. ET patients reported higher frequency of the presence of high voice intensity, tremor, and struggle. Several acoustic parameters were influenced by the severity of the disease, including shimmer, jitter, H/N ratio, frequency variability of the sentence, and s/z ratio, although neither of the acoustic analysis values or the phonetometric measurements were affected by the presence of voice tremor or by a successful pharmacological treatment of ET.

Aged↗
PubMed1998

Diagnostic evaluation of a synthetic peptide derived from a novel antigen B subunit as related to other available peptides and native antigens used for serology of cystic hydatidosis.

A synthetic peptide (GU4) derived from an antigen B (AgB) subunit was serologically compared with crude antigen (HCFA); immunopurified AgB and antigen 5 (Ag5), and two other synthetic peptides, for diagnosis of human cystic hydatidosis. GU4 was derived from the sequence of AgB/2, the novel AgB subunit described by us. The other two peptides: 65 (AgB mimotope) and 89-122 (Ag5 mimotope), were described by others. Antigens B and 5 showed higher diagnostic sensitivity than corresponding peptides. All sera reacting with peptides 89-122 and GU4 also reacted with 65. The latter provided three to four times higher sensitivity than the former two peptides, but 30% lower specificity. The diagnostic efficiency of AgB (82%) was higher than those of Ag5 (74%) and HCFA (71%). Interestingly, 89-122 only reacted with hydatid sera, some of which did not react with AgB. Considering positive those reacting with 89-122 or AgB, sensitivity increases from 77% (with AgB) to 82% (combined), while specificity is the same as with AgB (86%). Our results suggest that hydatid serology may be improved by: a) combining several defined antigens (including synthetic peptides), b) design of new E. granulosus-specific mimotopes, which react with the false negative sera (16/90; 18%).

Animals↗
PubMed1998

Fc-binding molecules specific for human IgG1 and IgG3 are present in Echinococcus granulosus protoscoleces.

In this work we describe the presence of Fc-binding activity on the suckers and tegument of E. granulosus protoscoleces. A fraction (PSA-Fc+) from protoscolex somatic antigens was isolated by affinity chromatography on human Fc-gamma1-Sepharose. Analysis by SDS-PAGE of PSA-Fc+ showed that it contained two major components. Using mouse F(ab')2-human Fc chimaeric monoclonal antibodies we verified that PSA-Fc+ bound mainly to human Fc-gamma1 and Fc-gamma3 isotypes. In addition, one of the components of PSA-Fc+ showed proteolytic activity. Both, Fc-binding and proteolytic activities localized on the protoscolex surface, may play a relevant role in the host-parasite interaction.

Animals↗
PubMed1998

Relevance of circulating antigen detection to follow-up experimental and human cystic hydatid infections.

We analysed specific antibody (Ab) and circulating antigen (CAg) profiles along experimental mouse infection using as control a group of mice immunized with intact but dead parasites. Results from this experiment showed an early major CAg peak followed by a larger Ab peak which partially overlaps with other minor CAg peaks. These results suggest that CAg may be a marker of early mouse infection. In order to study the relevance of these findings in humans we similarly analysed by ELISA 148 sera provided by retrospective post-surgical follow-up of 19 patients. Available records showed that 14 patients developed new cysts one to ten years after surgery while no new disease was observed in the-other five. Some of the former patients showed CAg, as early as two months after surgery while no CAg was observed in the other five patients at any time. In addition, a collection of 38 sera obtained before surgery were similarly tested and five of them showed only CAg, while 18 showed only Ab and 12 sera showed Ab&CAg. These results in humans are consistent with the findings in the mouse experimental model and suggest that CAg may be an early marker of hydatid infection, thus being relevant for post-surgical follow-up.

Animals↗
PubMed1998

Neonatal morbidity associated with disproportionate intrauterine growth retardation at term.

We set out to compare neonatal morbidity between disproportionate intrauterine growth retarded newborn infants and proportionate retarded ones at term, based on ponderal index. This is a prospective study of 185 single pregnancies with evidence of intrauterine growth retardation at term. Sixty three cases (34%) were disproportionate and 122 (66%) proportionate in terms of ponderal index. All were born in the University Hospital 'Principe de Asturias' of Alcala de Henares, Madrid, Spain. Proportionate or disproportionate intrauterine growth retardation diagnosis was established using the ponderal index (weight/length3). The following outcomes of neonatal morbidity were investigated: (1) perinatal asphyxia (meconium-stained amniotic fluid, abnormal fetal heart rates, newborn acidosis or low Apgar score 7 at 5 minutes) and/or (2) early neonatal medical complications. Disproportionate intrauterine growth retardated newborn infants presented higher rates of perinatal asphyxia (54% vs. 32%, P 0.01), with higher abnormal fetal heart rates (37% vs. 15%, P 0.01), higher frequency of arterial pH 7.20 (31% vs. 16%, P 0.05); and also higher rates of early neonatal medical complications (40% vs. 11%, P 0.001), mainly hypoglycaemia (25% vs. 4%, P 0.01). Morbidity among disproportionate intrauterine growth retardated Aconates is significantly higher compared with proportionate ones, demonstrating the heterogeneity of the intrauterine growth retardation population. Proportionate and disproportionate intrauterine growth retardation should be diagnosed as early as possible, since the majority of the morbidity is intimately related to this difference.

Journal Article↗
PubMed1998

Cloning and sequencing of the cDNA coding for pig pre-uteroglobin/Clara cell 10 kDa protein.

Using reverse transcription-polymerase chain reaction (RT-PCR) on pig lung mRNAs, we have cloned and sequenced an almost full-length complementary DNA (cDNA) coding for pig pre-uteroglobin/Clara cell 10 kDa protein (UG/CC10), a major secretory protein of lung Clara cells. The deduced amino acid sequence indicated a preprotein of 91 residues, 21 of which corresponded to the signal peptide. Comparison of the sequence with those of known pre-UG/CC10 from other species indicated that the pig protein resembles the structure shared by human and Lagomorpha pre-UG/CC10 but differ from the proteins from Rodentia that are composed of 96 aminoacids and contain signal peptides of 19 residues. Some amino acids, that form part of a hydrophobic pocket inside the mature protein, are well conserved in all UG/CC10 suggesting an important function of this cavity. Northern analysis indicated that pig UG/CC10 mRNA is abundant in lung but is not detectable in liver, uterus or epididymis. The results are discussed in relation to a possible physiological function of UG/CC10.

Animals↗
PubMed1998

The PA influenza virus polymerase subunit is a phosphorylated protein.

The induction of proteolysis by expression of the influenza virus PA polymerase subunit is the only biochemical activity ascribed to this protein. In the course of studying viral protein synthesis by two-dimensional gel electrophoresis, we observed the existence of several PA isoforms with different isoelectric points. These isoforms were also present when the PA gene was singly expressed in three different expression systems, indicating that a cellular activity is responsible for its post-translational modification. In vivo labelling with [32P]orthophosphate, followed by two-dimensional gel electrophoresis, clearly demonstrated the incorporation of phosphate into the PA molecule. Phosphoserine and phosphothreonine epitopes were present in PA, while phosphotyrosine residues were absent, as tested by immunoblotting with specific antibodies. These facts, as well as the presence of multiple consensus sites for casein kinase II (CKII) phosphorylation, prompted us to test the involvement of this kinase in PA covalent modification. PA protein purified by immunoprecipitation could be specifically labelled by the catalytic alpha subunit of human CKII, which was expressed and purified from bacteria. Collectively, these data demonstrate that the PA subunit of the influenza virus RNA polymerase is a phosphoprotein.

Animals↗
PubMed1998

HSP70 gene polymorphisms in ankylosing spondylitis.

Despite the strength of the association of ankylosing spondylitis (AS) with HLA-B27, other genetic elements could play a possible role in the pathophysiology of AS. Because of the localization, in the proximity of the HLA-B locus, and the involvement of heat shock proteins (HSP) in the immune response, we analyzed the influence of HSP70 gene polymorphism on the susceptibility to AS. HSP70-1, HSP70-2 and HSP70-hom genotypes were analyzed by PCR-RFLP in patients with AS and in healthy controls. The results obtained in the present study showed that there are not significant differences in the distribution of HSP70-hom genotypes, whereas significant differences in HSP70-1 and HSP70-2 genotypes between AS patients and random controls were found. However, when the distribution of these genotypes were compared in B*27-matched AS patients and controls, the differences disappeared. These data suggest that the polymorphism of HSP70 genes was not independently associated with AS, and that the differences in HSP70-1 and HSP70-2 genotypes among AS patients and controls appears to be due to the linkage disequilibrium between HSP70 alleles and HLA-B*27.

Alleles↗
PubMed1998

Tumor necrosis factor gene polymorphisms in ankylosing spondylitis.

Despite the strength of the association of ankylosing spondylitis (AS) with HLA-B27, other genetic elements could play a possible role in the pathophysiology of AS. In view of its gene location, in the proximity of the HLA-B locus, and biological effects, tumor necrosis factor (TNF) genes are potential candidates for additive susceptibility factors to AS. TNFalpha and TNFbeta genotypes were analyzed by PCR-RFLP in 57 patients with AS, 102 random controls and 30 HLA-B*27-positive controls. No significant differences of TNFalpha promoter variations at position -308 and -238 were found in AS patients in comparison with controls. The -244 polymorphism was not detected in our population. The TNFbeta genotype frequency was significantly different between AS patients and random controls. However, when the distribution of the TNFbeta genotype was compared in B*27-positive AS patients and controls, these differences disappeared. In addition, we demonstrated that the TNFbeta*1 was in strong linkage disequilibrium with the B*27 allele, which may explain the differences observed for the TNFbeta genotype among AS patients and random controls. Our data suggest that the polymorphisms of TNFalpha and TNFbeta genes do not have an independent effect on AS susceptibility.

Alleles↗
PubMed1998

Polymorphisms at tumor necrosis factor (TNF) loci are not associated with Chagas' disease.

The aim of this study was to investigate whether the polymorphisms at the TNF loci are associated with Chagas' disease. We determined the TNFA (positions -308, -244 and -238) and TNFB genotypes in a sample of 85 serologically positive chagasic individuals and in 87 healthy controls from a Peruvian population where Trypanosoma cruzi infection is endemic. Patients were subdivided according to the presence (n= 33) or absence (n =52) of chagasic chronic cardiomyopathy, in order to search for genetic differences associated with this pathological condition. No significant differences either between patients and controls or between asymptomatic and cardiomyopathic individuals were observed with respect to TNFA or TNFB polymorphisms when these were considered individually or as extended haplotypes.

Chagas Disease↗
PubMed1998

HLA-B*27 subtyping by PCR-RFLP in Spanish patients with ankylosing spondylitis.

We describe the use of restriction analysis on PCR-amplified DNA for detecting all B*27 subtypes except B*2710 and B*2711 (i.e. from B*2701 to B*2709). After detecting B*27 by Sty I, double digestions consisting of Sty I plus another informative enzyme led to subtype assignment. We used mismatched primers to create restriction sites when necessary. The method avoids group-specific amplifications and other laborious optimization procedures. It was successfully tested on a panel of well characterized cell lines covering different B*27 subtypes. Then, we studied a group of 57 ankylosing spondylitis patients and 746 controls from the south of Spain. B*27 showed a very strong association with the disease (OR=211.27, P=10(-7)). B*2702 and B*2705 distribution in controls (20% and 77.1%, respectively) differed from previously reported data in the Spanish population. We unexpectedly found the B*2707 allele in our population (one control).

HLA-B27 Antigen↗