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Biomedical subjects

E Rodríguez

Publications and source records attributed to E Rodríguez.

At least 127 records · Page 7Linked to original sources
PubMed1997

Combined effect of bacteriocin-producing lactic acid bacteria and lactoperoxidase system activation on Listeria monocytogenes in refrigerated raw milk.

The bactericidal activity of three bacteriocin-producing lactic acid bacteria alone and in combination with milk lactoperoxidase (LP) system activation against Listeria monocytogenes in refrigerated raw milk was studied. After 4 d at 4 degrees C, the population of L. monocytogenes in milk inoculated with bacteriocin-producing Lactococcus lactis subsp. lactis ATCC 11454, L. lactis subsp. lactis ESI 515 or Enterococcus faecalis INIA 4 was reduced by 0.21-0.24 log units. Activation of the LP system did not enhance inhibition at this temperature. After 4 d at 8 degrees C, L. monocytogenes levels in the non-activated LP system milk inoculated with L. lactis subsp. lactis ATCC 11454, L. lactis subsp. lactis ESI 515 or Ent. faecalis INIA 4 were reduced by 1.87, 1.54 and 1.11 log units compared to control milk, whereas in the activated LP system milk, this reduction was 1.99, 2.10 and 1.06, respectively. The higher nisin production by L. lactis subsp. lactis ESI 515 in milk with activated LP system than in non-activated LP system milk was responsible for the more pronounced decrease of L. monocytogenes counts in the former.

Animals↗
PubMed1997

Magnetic resonance imaging of apical hypertrophic cardiomyopathy.

To assess the capability of magnetic resonance imaging (MRI) to define the presence, degree, and distribution of apical hypertrophic cardiomyopathy in patients of European descent, MRI examination was prospectively performed in patients diagnosed with hypertrophic cardiomyopathy on two-dimensional echocardiography. Twenty-five patients with hypertrophy located exclusively at the cardiac apex were the object of this study. Spin echo and gradient echo sequences were performed to evaluate the morphology, motility, and myocardial thickness of the left ventricle in diastole. In a short-axis gradient echo sequences from base to apex, septal, lateral, anterior, and posterior segments at the basal and apical levels were measured. A four-chamber view and horizontal long-axis images of the left ventricle were performed to measure the true apex. A concentric, symmetric distribution of hypertrophic myocardium was considered when the thickness was 1.5 cm or greater, with the four segments being affected to a similar degree. Asymmetric hypertrophy was considered when the wall thickness ratio was more than 1.3. Myocardial thicknesses at the apical level were 2.03 +/- 0.60 cm (mean +/- standard deviation) at the true apex; the septal thickness was 1.19 +/- 0.46 cm; lateral, 1.62 +/- 0.71 cm; anterior, 1.36 +/- 0.57 cm; and posterior, 1.28 +/- 0.53 cm. Based on the MRI findings, the distribution of apical hypertrophy was classified as symmetric (n = 2), asymmetric (n = 18), and true apex (n = 5). A spadelike configuration of the left ventricle was observed in only five cases. MRI demonstrates that in Western patients the morphologic spectrum of apical hypertrophy cardiomyopathy is quite wide and includes myocardial hypertrophy exclusively localized at the true apex.

Adult↗
PubMed1997

[Modulation of P-fimbriation by ciprofloxacin in uropathogenic Escherichia coli].

BACKGROUND: The aim of this study was to determine the effect of ciprofloxacin at subinhibitory concentrations on the expression of P fimbriae of uropathogenic Escherichia coli. Thirty-nine strains of Escherichia coli isolated from out patients with urinary tract infection were studied. Thirty-nine of these strains had been previously characterized as P-fimbriated and the remaining non fimbriated strain was used as a negative control. METHODS: Fimbriation was quantitatively studied by electron microscope observation of the strains before and after treatment. To determine possible qualitative variations in the fimbrial proteins and in the external membrane (OMPs), extraction and electrophoretic separation was performed in polyacrylamide gels. RESULTS: No qualitative differences were observed in the OMPs profile and fimbrial proteins induced by ciprofloxacin in any of the strains studied. However, electron microscopic observation generally showed a decrease in the percentage fimbriated bacterial cells by the antimicrobial effect. CONCLUSIONS: The mechanism of action of ciprofloxacin at subinhibitory doses may correspond to a process of fimbrial protein synthesis inhibition secondary to the initiation of general repair mechanism of the cell exposed to the antimicrobial and not to a process of specific mutations which qualitatively affect fimbrial protein composition.

Anti-Infective Agents↗
PubMed1996

Sulfonylureas stimulate glucose uptake through GLUT4 transporter translocation in rat skeletal muscle.

We studied the effect of gliclazide on glucose uptake and GLUT4 translocation in skeletal muscle. Rat hindquarters were perfused in the absence or presence of gliclazide (300 micrograms/ml), insulin or both drugs. The basal glucose uptake was increased 2.7-fold by gliclazide (p < 0.05). Gastrocnemius muscles perfused with gliclazide had a significant increase (2.4-fold) in the GLUT4 content in plasma membranes compared to basal conditions (p < 0.05). The stimulations produced by 1 nM insulin on muscle glucose uptake (2.8-fold) and on GLUT4 level in plasma membranes (2.5-fold) were similar to those produced by gliclazide. The effect of insulin on the glucose uptake and on the GLUT 4 translocation was significantly enhanced by gliclazide (3.4-fold and 3.7-fold vs basal, respectively). These data show that sulfonylureas stimulate glucose uptake in skeletal muscle by promoting the movement of GLUT4 to the plasma membrane.

Animals↗
PubMed1996

Age-related changes in fibre composition of the human corpus callosum: sex differences.

We found positive correlations between the number of myelinated callosal fibres > 1 micron in diameter and age in humans. The relatively abundant axons with diameters between 1 and 3 microns correlated with age only in females, while the scarce fibres > 3 microns in diameter correlated significantly with age only in males. When analysing different callosal segments, it was found that in the midbody (but not in the splenium) of females the number of fibres > 3 microns also increased with age. In males, the relationship between these large diameter fibres and age disappeared after dividing the callosum into distinct segments. There may, therefore, be sex differences in the course of callosal fibre growth and myelination during the normal lifespan.

Adult↗
PubMed1996

Ethanol production by a mixed culture of flocculent strains of Zymomonas mobilis and Saccharomyces sp.

Pure and mixed cultures of Zymomonas mobilis and Saccharomyces sp. were tested for the production of ethanol using sucrose as the carbon source. Both strains, isolated from spontaneously fermenting sugar-cane juice, are flocculent and alcohol-tolerant. The best results were obtained using a mixed culture, with a yield of 0.5 g ethanol/g sugar consumed and a volumetric productivity of 1.5 g ethanol l-1 h-1. No levan was produced even if a sucrose-based medium was used.

Ethanol↗
PubMed1996

Characterization of Spanish Trichinella isolates by random amplified polymorphic DNA (RAPD).

The random amplified polymorphic DNA (RAPD) assay was used to find molecular markers able to distinguish Trichinella spiralis from T. britovi, the two recognized Spanish Trichinella species. Fourteen Spanish Trichinella isolates, as well as reference Trichinella isolates representing the five species T. spiralis (T1), T. nativa (T2), T. britovi (T3), T. pseudospiralis (T4) and T. nelsoni (T7) and the three other taxa Trichinella T5, Trichinella T6 and Trichinella T8 of the genus, were characterized by RAPD using both purified and crude DNAs from infective muscle larvae (ML) and seven arbitrary primers. Three primers yielded diagnostic RAPD markers for the Spanish T. spiralis and T. britovi isolates as well as for the Trichinella reference isolates analysed, and in the case of crude DNAs the results were obtained in few hours. In addition, the species-specificity of the diagnostic RAPD markers from Spanish Trichinella isolates was studied by cross-hybridization assays. These assays confirmed that the selected diagnostic DNA fragments were not species-specific, but showed potential differences in the copy number among the examined Trichinella genetic clusters.

Animals↗
PubMed1996

Adenovirus uncoating and nuclear establishment are not affected by weak base amines.

We have used four established lysosomotropic agents, ammonium chloride, amantadine, chloroquine, and methylamine, to monitor the possible interference with an early low-pH-dependent step during adenovirus replication. Two concentrations of each of the different agents were selected; one was essentially nontoxic to uninfected HeLa cells, and the other resulted in some toxicity as measured by trypan blue staining and by interference with cell monolayer establishment, cell proliferation, and radioisotope labelling. It was separately determined that these concentrations displayed pH-raising effects of the same magnitude as higher concentrations previously used in similar studies. Adenovirus uncoating in vivo, normally reaching its maximum within 1 h after infection, was not affected by any of the agents. The subsequent levels of successful nuclear entry events by the parental genomes were monitored by measuring the extent of transcription of an mRNA species coding for the early 72-kDa DNA-binding protein at 10 to 12 h postinfection. In HeLa, KB, HEp-2, and A549 cells, none of the agents were able to affect the levels of early transcription after administration at the point of infection or at 3 h after infection. The cumulative synthesis of the hexon antigen was assessed late in infection, and inhibitory effects were revealed upon administration of 10, 20, and 40 mM ammonium chloride, 10 mM methylamine, and 0.5 mM amantadine, irrespective of the time point of addition. Ammonium chloride at 5 mM reduced the hexon yield by 20% at the most when added within 50 min after infection. Chloroquine at concentrations of 2.5 and 5 microM specifically reduced the hexon yields by 30 to 40% when administered within the first 50 min of infection. On the basis of the lack of effects of nontoxic concentrations of the four agents on the early virus-cell interactive event of uncoating and the early virus-specified transcription, we conclude that a low-pH-dependent step early in the adenovirus replication cycle is not mandatory for a successful infection.

Adenoviridae↗
PubMed1996

[Thromboendarterectomy as a treatment for chronic pulmonary hypertension].

Chronic pulmonary hypertension is an extremely difficult disease to diagnose and is usually identified by the exclusion of other more recognized causes of enlargement in mean pulmonary arterial resistance. Up to now, treatments proposed for this disease, have not been very successful. Medical procedures are not a long term proper solution which leads the process to an irreversible point whose only solution should be a pulmonary transplantation. In recent years, study groups have established a surgical method, alternative to transplantation, which has been able to increase, with a decrease in mortality rates, a longer and a better quality of life for the patients affected by this disease: we are talking about pulmonary thromboendarterectomy.

Chronic Disease↗
PubMed1995

Light- and electron-microscopic immunocytochemical investigation of the subcommissural organ using a set of monoclonal antibodies against the bovine Reissner's fiber.

Ten monoclonal antibodies (Mabs) against glycoproteins of the bovine Reissner's fiber (RF) have been used in a structural and ultrastructural immunocytochemical investigation of the bovine subcommissural organ (SCO) and RF. The SCO of other vertebrate species has also been studied. For comparison, polyclonal antibodies against bovine RF (AFRU) were used. The SCO and RF of ox, pig and dogfish and the SCO of dog, rabbit, rat and frog were submitted to light-microscopic immunocytochemistry using AFRU and Mabs. Postembedding ultrastructural immunocytochemistry was applied to sections of bovine SCO using AFRU and Mabs. Bovine SCO consists of ependymal and hypendymal cell layers, the latter being arranged as cell strands across the posterior commissure, or as hypendymal rosette-like structures. All cytoplasmic regions of the ependymal and hypendymal cells were strongly stained with AFRU. Six Mabs showed the same staining pattern as AFRU, one Mab stained RF strongly and SCO weakly, two Mabs stained RF but not SCO, and, finally, one Mab (3B1) exclusively stained the apices of the ependymal and hypendymal cells. All Mabs recognized the SCO and RF of the pig. Two Mabs bound to the SCO of the dog. One Mab stained the SCO of the rabbit and another the SCO of the rat. The SCO of frog and dogfish were totally negative. Bovine SCO stained with AFRU, showed label in the rough endoplasmic reticulum (RER) and the secretory granules (SG) of the ependymal and hypendymal cells. The former, in the form of parallel cisternae, reticulum or concentric rings, was seen throughout all cytoplasmic regions. SG were abundant in the apical pole of the ependymal and hypendymal cells. Only one Mab showed a staining pattern similar to AFRU. Five Mabs showed strong reactions in the SG but weak labeling of the RER. Mab 3B1 showed the label confined to the SG only. Our results suggest that: (i) in the bovine tissue, some epitopes are present in both precursor and processed materials, whereas others are characteristic of mature glycoproteins present in SG and the RF; (ii) the bovine SCO secretes at least two different compounds present in ependymal and hypendymal cells; (iii) both compounds coexist in the same secretory granule; (iv) there are conserved, class-specific, and species-specific epitopes in the glycoproteins secreted by the SCO of vertebrates.

Animals↗
PubMed1995

A new technique for laparoscopic repair of hypertrophic pyloric stenosis.

Since 1987, pyloric traumamyoplasty, a technique for the resolution of hypertrophic pyloric stenosis, has been used in 111 patients. Continuous prensile force is applied with Babcock intestinal clamps, with consequent rupture of the muscular layer, without disruption of the mucosa. Because this is a simple procedure that requires introduction of only one noncutting instrument, it has now been applied laparoscopically in 17 patients. Twelve were under 30 days of age; seven weighed less than 3.5 kg. The hospital stay averaged 1.8 days, and the average surgical time was less than 30 minutes. Only two trocar incisions were made in each case--one for the laparoscope video camera and lamp, the other for a modified Babcock clamp. There were no deaths and no complications related to the pyloric repair procedure. The authors conclude that laparoscopic pyloric traumamyoplasty is an attractive alternative for the management of hypertrophic pyloric stenosis.

Female↗
PubMed1995

MR imaging in inferior vena cava thrombosis.

PURPOSE: To prospectively evaluate the efficacy of MR imaging in inferior vena cava (IVC) thrombosis; to differentiate acute from non-acute thrombus, and to identify the presence of changes in the morphology and signal intensity during medical treatment. METHODS AND MATERIALS: Seventeen patients with suspected IVC thrombosis underwent 30 MR examinations. The IVC thromboses were subdivided into two groups (acute and non-acute) according to onset of clinical symptoms. MR imaging of the IVC was analyzed and when an IVC thrombus was identified, a qualitative and quantitative assessment of the thrombus on spin-echo sequences with magnitude and phase reconstruction was performed to evaluate the relationship between signal intensity and the time elapse since the onset of clinical symptoms. Venography and/or CT scan proof was available in all cases. RESULTS: IVC thrombus was correctly identified in 19 MR examinations which showed the size, localization and the degree of lysis during follow-up. No differences were found in the signal intensity of the thrombus related to time. The pattern of the signal intensity was homogeneous in six (86%) acute thrombus and heterogeneous in nine (75%) thrombus of more than 1 week duration. A significant statistical relationship (P < 0.01) existed between the thrombus age and differences in the pattern of signal intensity. CONCLUSIONS: MR imaging is accurate to assess the localization and size of IVC thrombus, similar to the imaging techniques of reference. In addition, MR also provides useful information about the age and the morphological variations of thrombus during medical treatment.

Acute Disease↗
PubMed1995

Iron, copper and zinc levels in urine: relationship to various individual factors.

Urinary Fe, Cu and Zn levels were determined in healthy people from S/C de Tenerife. Males showed higher (p < 0.01) urinary levels (micrograms/L and microgram per day) of Zn than females. However, females had higher daily urinary Fe and Cu excretions per kg of body weight (p < 0.05) than males. Urinary metal concentration, expressed as mg metal per g CT, better reflects daily excretion. Urinary levels of Zn and Cu were within the reference values, but the urinary levels of Fe were lower than that in most of the published data. An increase in daily Fe, Cu and Zn excretion (micrograms per day) with age up to 30 years was observed. An increase with weight and height was also observed. Concentrations and excretions of Zn were significantly (p < 0.015) lower when the urinary pH was above 7. With respect to the frequency of consumption of rich protein food, rich fiber food, coffee, tobacco, or alcohol, only significantly (p = 0.015) higher Zn concentrations and higher (p = 0.091) excretions were found in people that consume alcohol more than 3 times a week. A significant depletion of urinary Zn and Cu concentration and Fe excretion was found in the subjects who usually did physical exercise. Positive intermetallic correlations among the concentrations and excretions of the metals investigated were observed.

Adolescent↗