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Biomedical subjects

A Rodríguez

Publications and source records attributed to A Rodríguez.

At least 19 recordsLinked to original sources
PubMed1992

Primer design for specific diagnosis by PCR of highly variable RNA viruses: typing of foot-and-mouth disease virus.

A PCR assay for the specific detection and identification of viral sequences that correlate with established serotypes of foot-and-mouth disease virus (FMDV) has been developed. A new analysis based on homology profiles among reported sequences was used for primer design. RNA replicase (3D) gene regions that showed high homology among FMDVs, and low homology to other picornaviruses, were used for PCR amplification. Specific and highly sensitive detection was achieved for RNA of FMDV types C, A, and O, either purified or extracted from vesicular fluids of infected animals, under reaction conditions permissive for the detection of variants present in the virus population. Similarly, serotype-specific primers were designed to amplify the carboxy-terminal end of VP1 gene of FMDV types either C, A, or O. The results of PCR amplification of 15 different FMDV RNAs using type-specific primers are in agreement with the serological typing of the corresponding viruses and show that the primer-selection procedure developed for FMDV constitutes a reliable method of viral diagnosis.

Animals↗
PubMed1992

Heterotypic lymphoproliferative response in pigs vaccinated with foot-and-mouth disease virus. Involvement of isolated capsid proteins.

The in vitro viral lymphoproliferative response of pigs vaccinated against foot-and-mouth disease virus (FMDV) has been characterized. Peripheral blood mononuclear cells from immunized animals up to 1 year post-immunization (p.i.) showed a time-dependent FMDV-specific response, as assayed by virus-specific cellular blastogenesis. The optimum viral concentration decreased with time (around 20 weeks p.i.), and the response was faster and weaker. Lymphoproliferation appeared to be mainly due to CD4+ T cells. The response was heterotypic, being induced by all FMDV serotypes tested (C, A and O) after only two vaccinations with FMDV of serotype C (C-S8). Each individual structural protein assessed (VP1, VP2 and VP3) induced proliferation, with VP3 and VP1 being more effective stimulators. In vitro serum neutralization activity and FMDV-specific IgG production were found to be active even at 1 year p.i.

Animals↗
PubMed1992

Global transcription pattern of phi C31 after induction of a Streptomyces coelicolor lysogen at different growth stages.

Using two complementary strategies for low-resolution S1 mapping, the global pattern of phi C31 transcription was studied after induction of thermoinducible phi C31 lysogens of Streptomyces coelicolor A3(2). A complex pattern of early transcripts was seen, with a peak of abundance at about 10 min post-induction. Nearly all of these transcripts were from DNA located to the right of the c (repressor) gene and to the left of the attP site: a region of about 14 kb. Early transcription was also observed immediately to the left of the c gene. The c gene itself was also induced, with an earlier expression peak (about 5 min post-induction). Primary late transcripts were generally relatively long, but degraded. They apparently corresponded to most of the 18 kb region to the left of the c gene. Some shorter and more persistent late transcripts corresponded to DNA close to or overlapping the cos site. Large late transcripts from a region close to the left-hand end of the phi C31 genome showed evidence of processing to more stable, smaller RNA species. A failure of older cultures (more than 12 h old) to be induced productively was correlated with a much longer period of early transcription, reduced late transcription, failure to synthesize a major virion protein, and failure to package phi C31 DNA. Moreover, heat treatment of the older lysogenic cultures did not result in the phi C31-dependent shut-down of host rRNA transcription previously observed for young cultures (Rodríguez et al., Journal of General Microbiology (1986) 132, 1695-1701; Clayton & Bibb, Molecular Microbiology (1990) 4, 2179-2185).

Bacteriophages↗
PubMed1992

Immunocytochemical study of the diffuse neuroendocrine system cells in equine lungs.

This study was undertaken to investigate the presence of neuroendocrine cells (N.E.C.) by immunocytochemical means in equine lungs during three distinct evolutionary periods: fetal, neonatal and adult. The authors identified bombesin, somatostatin and calcitonin secretory cells. In the fetal lungs the N.E.C. were located in the interstitial tissue and exhibited greater immunoreactivity to bombesin than to the other two neuropeptides studied. A large number of calcitonin-producing cells and a smaller number of bombesin-positive cells were seen in the bronchial and bronchiolar epithelium of newborn Equidae. In the adult equine lungs far fewer N.E.C. were observed than in the earlier stages. Somatostatin-producing cells were not seen in neonatal or adult lung tissue.

Animals↗
PubMed1992

On the mechanism of stimulation of ureagenesis by gluconeogenic substrates: role of pyruvate carboxylase.

Gluconeogenic substrates, lactate or pyruvate, or ornithine produced 100% increase of urea synthesis from NH4Cl. The combined administration of ornithine and lactate (or pyruvate) produced more than additive effects, indicating that they acted at different steps in a potentiating manner. The uptake of ornithine was enhanced by gluconeogenic substrates. This finding may explain, at least in part, the stimulating effect of these substrates on ureagenesis from NH4Cl and ornithine. The gluconeogenic substrate-induced stimulation of ureagenesis from NH4Cl was still observed under conditions of reduced flux through pyruvate carboxylase, ruling out that their action was exclusively mediated by the anaplerotic effect of this enzyme. Pyruvate was a more potent stimulator of ureagenesis than lactate and its effect less sensitive to pyruvate carboxylase inhibition. These observations indicate that a correlation exists between stimulation of ureagenesis by gluconeogenic substrates and flux through pyruvate dehydrogenase. It is concluded that gluconeogenic substrates may stimulate ureagenesis from NH4Cl by 1) increasing intracellular ornithine availability and/or 2) enhancing flux through pyruvate dehydrogenase and consequently the tricarboxylic acid cycle activity.

Ammonium Chloride↗
PubMed1992

[Chlamydia trachomatis detection by DNA-RNA hybridization].

BACKGROUND: A one-chain DNA probe, that complements ribosomal RNA of Chlamydia trachomatis was used as a detection method for this microorganism on clinical samples. We compare the method with the cell culture one. METHODS: A total of 175 samples (cervix swabs) from women seen at the STD center of the Facultad de Medicina de Sevilla were examined by both diagnostic techniques. When the results were different, a third method (ELISA) was also used. RESULTS: Using serial dilutions of a C. trachomatis cell culture as reference pattern, we determine the minimum number of inclusion forming units needed in order to be detected by the probe was 1000. Of all 175 samples, in 24 (14%) cell culture was positive for C. trachomatis, and 26 were positive using the DNA probe test. Sensitivity and specificity for this test were 93% and 95%, respectively. CONCLUSIONS: We believe that the DNA probe test was similar to the cell culture test as screening test in Chlamydia trachomatis infections diagnosis, specially among high risk populations.

Chlamydia Infections↗
PubMed1991

Role of central dopaminergic pathways in the neural control of growth hormone secretion in normal men: studies with metoclopramide.

The aim of this study was to gain further insight into the role that central dopaminergic pathways play in GH neuroregulation in man. Our experimental hypothesis was based on the possibility that most of the controversies on DA role could be due to the fact that the hypothalamic somatotroph rhythm (HSR) was not taken into account when interpreting the GH responses after pharmacological manipulations on dopaminergic pathways. In 10 normal subjects we monitored the effect of central dopaminergic blockade, achieved with metoclopramide (MCP; 10 mg, i.v. bolus), on the pattern of spontaneous GH secretion and the GH responses to a GHRH challenge (GRF1-29, 1 microgram/kg, i.v. bolus) administered together with MCP or 60 min after this drug was given. The study of HSR was made according to our previous postulate. Our results indicate that MCP administration, either prior to or together with the GHRH bolus, significantly increased GHRH-induced GH release during a refractory HSR phase; but not when the GHRH challenge took place during a spontaneous secretory phase. The strong relationship between pre-GHRH plasma GH values and GHRH-elicited GH peaks was lost when MCP was given. These data indicate that MCP was able to disrupt the intrinsic HSR by inhibiting the hypothalamic release of somatostatin (SS). While a main conclusion would be that central DA is a secretagogue for SS secretion, our results also suggest that this role could be dependent on its effects on the adrenergic inputs to SS neurons.

Adult↗
PubMed1991

Distribution and function of the lethal of scute gene product during early neurogenesis in Drosophila.

Genes of the achaete-scute complex (ASC) participate in the formation of the central nervous system in the Drosophila embryo. Previous genetic analyses have indicated that lethal of scute (l'sc) is the most important gene of the complex in that process. We have obtained antibodies against the l'sc protein to study the expression of the gene during early neurogenesis. The protein is found in groups of embryonic neuroectodermal cells, analogous to the proneural clusters that precede the appearance of precursors of peripheral sensory organs in imaginal epithelia. The groups appear in different regions of the neuroectoderm, accompanying the three successive waves of neuroblast segregation. Most neuroblasts delaminate from these clusters and express position-specific levels of l'sc protein. No significant differences have been found between the distribution of l'sc RNA and protein. Phenotypic analysis of a l'sc deficiency has shown that the gene is required for neuroblast commitment, although this requirement is less widespread than the domain of l'sc expression, suggesting a high degree of redundancy in the function of genes that participate in the process of neuroblast segregation. The ASC genes have been postulated to play a role in the control of NB identity, revealed by the generation of a defined lineage of identifiable neurons. However, our study in l'sc mutants of the expression of fushi tarazu, engrailed, and even-skipped, used as markers of neuronal identity, has not provided evidence to support this hypothesis.

Animals↗
PubMed1991

[Digital coronary angiography. A new approach in the analysis of the arteriosclerotic plaque].

In order to define the coronary lesions we prospectively performed digital coronary angiographies in 61 patients. The degree of stenosis was measured in 100 lesions by quantitative analysis using densitometric and geometric methods. Two groups of lesions were found by comparing these two methods: Group A, 47 lesions with a poor correspondence in the degree of stenosis between densitometric and geometric analysis (p greater than 0.01; and group B, 53 lesions with a good correspondence. Both groups were correlated with plaque characteristics (unstable or stable), following angiographic criteria. The mean degree of stenosis in all lesions, for densitometric and geometric analysis was 50.04 +/- 21.1% and x 60.66 +/- 22.1% (p less than 0.01), respectively. Unstable plaque was more frequent in group A (80.9%) than in B (17.9%) (p less than 0.0001), and stable plaque was more frequent in B (81.1%) than in A (19.1%) (p less than 0.0001). Less degree of stenosis between A (41.5 +/- 13.2) and B (61.3 +/- 16.05) was found by densitometric analysis (p less than 0.0001) but it was similar by geometric method (60.02 +/- 11.3 in A and 58.6 +/- 14.4 in B) so that the degree of stenosis in unstable plaque was lower by densitometric method. We conclude that densitometric analysis showed poor correlation with geometric analysis in unstable plaques; the difference could be due to the soft component expression of the unstable plaque.

Aged↗
PubMed1990

[Nasosinusal inverted papilloma. A case report].

The AA. report a case of inverted nasosinusal Papilloma diagnosed and treated surgically, at their Hospital, through a combined approach paralateronasale and Caldwell-Luc. Review of the bibliography.

Aged↗
PubMed1990

[Intravesical echography. I. Anatomical correlation].

The scan images of the normal bladder were obtained by intravesical ultrasonography (IVU) and the ultrasonographic-anatomic correlation were defined based on 179 procedures. Except in bladder cancer, IVU did not prove to be useful in the evaluation of other bladder conditions or adjacent structures, including gynecological disorders.

Female↗
PubMed1990

Genetics of lactic acid bacteria with special reference to lactococci.

Lactic acid bacteria play an important role in the manufacture of fermented foods. Genetic studies have made these microorganisms, particularly lactococci, accessible to genetic manipulation. The instability of key metabolic traits of lactococci has been explained by the presence of plasmid DNA species. Most genetic interest has been focused to solve the quoted instability and the sensitivity to bacteriophage infection. At the same time, gene transfer systems have been developed and specific genes with commercial significance have been identified and cloned. Lactic acid bacteria can be also used as production organisms of heterologous proteins, e.g. chymosin, lysozyme.

Bacterial Proteins↗
PubMed1990

[Early angiographic study post successful angioplasty. Predictor of late restenosis].

Consecutive prospective coronary angiographies following 24 hours were studied to find early angiographic predictors of post-PTCA restenosis in the follow-up of 71 patients who had been dilated successfully. Conventional cine coronary and quantitative digital angiography was used to analyse the degree of obstruction previous to dilatation following 24 hours and 30 minutes after the procedure. Following 24 hours, angiographic findings showed: Group A: patients having the same lumen as at immediate post-PTCA time (65.9%); Group B: patients with 20% or more immediate post-PTCA time (21.5%). Group C: patients with total obstruction of vessel (12.6%). The basal clinical conditions were similar in the three groups. The degree of basal obstruction and the clinical findings were similar in the three groups; the dilated arteries in Groups A and B were similar and total occlusion before PTCA was more frequent in Group C than in B and A; 30 minutes post PTCA lesions in group A had less residual stenosis than group B (p less than .01) and C (p = NS), this difference increased significantly (p less than .0001) at 24 hours and in the late follow-up. In the follow-up (means 6.4 months) there was total restenosis per lesion in 32.9%. In Group A, there was 8.6%; in Group B, 68.4% (p less than .0001) and in Group B plus C, 80%. Patients with more than 10% obstruction had a greater degree of restenosis (43.9%) than when the initial lesion was less than 10% (23.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1989

A prospective study of a rapid method for diagnosing cytomegalovirus infections in immunosuppressed patients.

A rapid assay is described for detection of cytomegalovirus in peripheral blood lymphocytes. It consists of an indirect immunofluorescence technique for detection of cytomegalovirus antigens by means of a monoclonal antibody directed against early viral coded proteins. This assay was compared with the conventional cell culture system. Patients transplanted between December 1986 and May 1988 were studied, and of 27 patients identified, two were excluded due to early graft failure. A total of 320 blood specimens obtained were studied, and from 12 patients cytomegalovirus was isolated in at least one specimen by conventional cell culture (in total 25 specimens). Results were available with the new technique within 6 h, whereas the cell culture took an average of 13 days to develop the typical cytopathic effects changes. Sensitivity and specificity compared with that of viral isolation in conventional cell culture was 92% and 95%, respectively. This technique provides an accurate and rapid diagnosis of cytomegalovirus infections, and allows specific antiviral therapy to be started earlier.

Antibodies, Monoclonal↗
PubMed1989

[Ultrastructure of the intracellular development of bacteriophage phi C 31].

The intracellular development of the bacteriophage phi C31 in thermally induced cultures of the lysogen Streptomyces coelicolor 01 changes remarkably its cell structure. At 10 min post-induction, a big number of mesosomes are shown by the cells. At 30 min post-induction, the cytoplasm contains capsids which are still empty. At the end of the latent period mature virions are shown and immediately after, cell lysis occurs through the tip of germinative tubes. In old cultures (10 h or more) no viral progeny is detected. However, when the amino acid glycine is added to the culture medium, new virions are seen, but in smaller number than in germinating cultures. These results seem to indicate that the lysis happens at the tip of the germinative tubes probably because this is an area weakened by the preferential growth that takes place on it.

Bacteriophages↗