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Biomedical subjects

J M Navarro

Publications and source records attributed to J M Navarro.

17 recordsLinked to original sources
PubMed1992

Isolation and characterization of the ecto-5'-nucleotidase from a rat glioblastoma cell line.

5'-Nucleotidase has been purified from rat glioblastoma cells (Rugli cells). The enzyme has been solubilized from plasma membranes by using Triton X-100 and CHAPS. Two affinity chromatographies on concanavalin A and 5'-AMP-Sepharose render the purified enzyme with a high specific activity (76.36 mumol AMP.min-1.mg-1). The purified enzyme gives a single polypeptide band on SDS-PAGE with an apparent molecular mass of 74 kDa. Active forms with an apparent molecular mass of 135 kDa and 268 kDa are observed when the purified enzyme is analyzed by gel filtration in the presence of either 0.6% sodium deoxycholate or 0.1% Triton X-100, respectively. The purified 5'-nucleotidase presents optimum activity at pH 7.8-8.1 either in the presence or in the absence of Mg2+. A linear Arrhenius plot is observed in the 25-46 degrees C temperature range and an activation energy of 33.7 KJ/mol is calculated. The enzyme is inhibited by EDTA; the activity is partially restored by different divalent cations as Zn2+, Mn2+, and Co2+. The hydrolysis of nucleosides 5'-monophosphate shows Michaelis kinetic. The enzyme is inhibited by nucleosides di- and triphosphate. 5'-Nucleotidase is a glycoprotein, being its activity inhibited at different extent by various lectins.

5'-Nucleotidase↗
PubMed1992

Evaluation of three rapid enzyme immunoassays and cell culture for detection of respiratory syncytial virus.

Three rapid enzyme immunoassay techniques for the detection of respiratory syncytial virus antigen (Becton Dickinson Directigen RSV, Abbott RSV Testpack and Abbott RSV EIA) and cell culture were evaluated in a total of 250 nasal washings. The sensitivity and specificity were 62% and 76% respectively for Directigen, 64% and 86% for RSV Testpack, and 76% and 81% for RSV EIA, taking cell culture as the reference method. Agreement between cell culture and EIA techniques was 79% (70 positive and 128 negative results). All three EIA techniques gave positive results in 69 samples (52 positive and 17 negative in the cell culture). In 121 samples all three EIA techniques gave negative results (103 negative and 18 positive in the cell culture). Using the cell culture technique 46 strains other than respiratory syncytial virus were isolated.

Animals↗
PubMed1992

Alcoholic glucose and xylose fermentations by the coculture process: compatibility and typing of associated strains.

As part of the simultaneous fermentation of both glucose and xylose to ethanol by a coculture process, compatibilities between xylose-fermenting yeasts and glucose-fermenting species were investigated. Among the Saccharomyces species tested, none inhibited growth of the xylose-fermenting yeasts. By contrast, many xylose-fermenting yeasts, among the 11 tested, exerted an inhibitory effect on growth of the selected Saccharomyces species. Killer character was demonstrated in three strains of Pichia stipitis. Such strains, despite their high fermentative performances, cannot be used to ferment D-xylose in association with the selected Saccharomyces species. From compatibility tests between xylose-fermenting yeasts and Saccharomyces species, pairs of microorganisms suitable for simultaneous xylose and glucose fermentations by coculture are proposed. Strains associated in the coculture process are distinguished by their resistance to mitochondrial inhibitors. The xylose-fermenting yeasts are able to grow on media containing erythromycin (1 g/L) or diuron (50 mg/L), whereas the Saccharomyces species are inhibited by these mitochondrial inhibitors.

Candida↗
PubMed1992

[Acute posttraumatic myocardial infarct: the necessity of an early interventionist posture].

We describe five cases of posttraumatic anterior acute myocardial infarction in young patients, without previous heart disease. One case was treated with intracoronary thrombolysis and angioplasty, 3 cases received systemic thrombolysis, and the last one did not have any re-permeabilization therapy, having arrived to the hospital 72 hours after the episode. The coronary angiograms showed at the left anterior descending artery: thrombosis in 3 cases, coronary dissection in one case, and slow flow with no morphological lesions in the other. The case which not received thrombolytic therapy developed a severe left ventricular dysfunction. In conclusion we emphasize an early angiographic study, in order to decide the re-permeabilization therapy.

Accidents, Traffic↗
PubMed1991

Acute myocardial infarction after blunt chest trauma in young people: need for prompt intervention.

We describe four cases of acute myocardial infarction in young patients, secondary to blunt chest trauma. One case was treated with intracoronary thrombolysis and angioplasty, two cases received systemic thrombolysis, and the last one did not have any reperfusion therapy. The coronary angiograms of the left anterior descending artery showed thrombosis in two cases, coronary dissection in one case, and no morphological lesions in the other. We encourage the early performance of angiographic studies in these patients, adjusting the therapy to their pathophysiologic mechanism.

Accidents, Traffic↗
PubMed1991

Eating epilepsy.

Eating epilepsy is a rare type of reflex epilepsy. A 24 years-old male with eating reflex complex partial seizures was submitted to clinical, neurological, neuroradiological and EEG studies. Neurologic and CT examinations were normal. EEG recordings including video-EEG monitoring during meals disclosed focal abnormalities related to both temporal lobes prevailing at the left side and secondary bilateral synchrony mainly in more anterior regions. Ictal findings were similar to the interictal secondary bilateral synchrony except for its longer duration. PB, VPA and DPH monotherapies were ineffective. High dose CBZ monotherapy yielded good but incomplete seizure control. Since a big number of precipitants could be involved, no specific physiopathological basis could be established.

Adult↗
PubMed1991

[Effect of the extraction of LPS (R) on the demonstration of the serological response in acute brucellosis by immunoblotting].

In order to establish the possible influence of Brucella melitensis rough strains protein extracts contamination using LPS (R) in the immunoblotting evaluation of serologic response, we have studied sera samples from 41 patients with acute brucellosis before treatment was started and also from 62 healthy individuals (control group). A whole-cell B. melitensis 115 strain extract with an without LPS (R) was used. Extraction was carried using ether-chloroform of oil-phenol. Overall, more than 50% of patients showed an antibody response (protein bands 85, 53, 50, 47, 41, 38 and 28 kD) to both antigenic products. Less than 6.4% of the control group sera showed response to any of these protein bands. There were no significant differences in the frequency of response development against these proteins using the two antigen types. However, there was some disagreement when each individual band response was compared to its homologous band.

Acute Disease↗
PubMed1990

[Pattern of antibodies in acute human brucellosis defined by Western blotting].

We have evaluated with Western blotting the serologic response of 144 patients with acute brucellosis and 62 healthy controls to identify a useful antibody pattern to confirm the diagnosis of acute brucellosis. The antigen that we used was a protein extract of whole cells of the strain 115 (rough) of B. melitensis. Patients sera were obtained at the time of diagnosis and before the start of specific therapy. There was antibody response to 21 protein bands. The molecular weights (MW) and frequencies of the most significant bands were the following: 85 Kd (60.4%), 70 Kd (54.1%), 53 Kd (63.9%), 50 Kd (65.3%), 47 Kd (71.5%), 41 Kd (74.3%), 38 Kd (68.7%), 33 Kd (56.2%), 28 Kd (52.8%). At the time of diagnosis, 90.3% of the patients with acute brucellosis had antibody response to 2 or more protein bands of Mw of 47 Kd, 41 Kd, 38 Kd and 33 Kd. In none of the 62 negative control sera there was a response to more than one of the mentioned bands.

Acute Disease↗
PubMed1987

[Ultrasound-guided percutaneous ureterostomy].

The authors present a new technique for percutaneous insertion of a drain into the upper urinary tract, using the direct lumbar transureteric approach under ultrasonographic control. This ultrasound-guided percutaneous ureterostomy was performed in two patients to drain the upper urinary tract and to evaluate the adjacent renal parenchyma. In both cases, ureterostomy was preferred to nephrostomy because of the difficulties of performing the latter operation and because of the considerable dilatation of the ureter.

Adult↗
PubMed1976

[Studies on the mechanism of interaction of glutaraldehyde with microorganisms (author's transl)].

The antimicrobial action of glutaraldehyde on Candida lipolytica increases with reagent concentration, pH and duration of contact. The simultaneous study of the size distribution of the particles shows an agglutination of the cells. This result is confirmed by direct observation of the cells by electron microscopy. Cell agglutination also occurs with other microorganisms (Saccharomyces carlsbergensis, Bacillus megaterium, Escherichia coli) and increases their settling rate. The formation of such intercellular bonds seems to confirm the hypothesis of a preferential action of glutaraldehyde on the outer layers of the cells. The effect of pH on the antimicrobial action of glutaraldehyde is accounted for by the fact that this reagent does not act, under neutral and alcaline conditions, as a dialdehyde but as an unsaturated polymer. This mechanism also accounts for various observations made on microorganisms-glutaraldehyde interactions.

Agglutination↗
PubMedDate not supplied

C-reactive protein as a prognostic indicator in acute brucellosis.

Pre- and post-treatment measurements of C-reactive protein (CRP) in 85 patients with acute brucellosis were useful in predicting the disease's evolution and response to treatment. A positive value for CRP (greater than 1 microgram/dl) was significantly associated with an unfavorable course, with a negative predictive value of 0.95.

Acute Disease↗
PubMedDate not supplied

[Electroencephalographic study of patients with panic disorders].

Electroencephalographic changes were studied in 27 patients with panic disorder and agoraphobia with panic attacks due to some clinical similarities between panic disorder and temporal lobe epilepsy. The EEG records, obtained with sleep deprivation, photostimulation and hyperventilation showed no abnormalities.

Adult↗
PubMedDate not supplied

[Alcohol fermentation: effect of temperature on ethanol accumulation within yeast cells (author's transl)].

During fermentation, yeast growth is rapidly stopped when the concentration of alcohol in the medium increases but fermentive activity is not entirely inhibited until high alcohol concentrations are reached. The rate of alcohol accumulation within the cells and certain kinetic parameters were simultaneously determined in such fermentative processes using Saccharomyces carlsbergensis cells. The growth inhibitory effect of alcohol was related to its retention inside within the cells; i.e. yeast multiplication is stopped when intracellular alcohol concentration reaches a maximum value. Moreover, the higher the temperature, the deeper the inhibitory effect of ethanol and the higher the maximal intracellular alcohol concentration. Activation energy determinations showed that ethanol accumulation within the cells was a consequence of the resistance to its diffusion through the cell wall from within to outside the cell.

Cell Division↗