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Biomedical subjects

R Muñoz

Publications and source records attributed to R Muñoz.

At least 109 records · Page 6Linked to original sources
PubMed1991

Intercontinental spread of a multiresistant clone of serotype 23F Streptococcus pneumoniae.

Isolates of serotype 23F Streptococcus pneumoniae with high levels of resistance of penicillin have been commonly recovered in Spain for more than a decade. Recently penicillin-resistant serotype 23F S. pneumoniae strains were also isolated from children attending a day-care center in Cleveland. A number of Spanish and Cleveland isolates were compared by electrophoretic analysis of penicillin-binding protein (PBP) profiles and DNA restriction endonuclease cleavage profiles of the PBP 2X and 2B genes amplified with the polymerase chain reaction and by multilocus enzyme electrophoresis. All strains were identical by these criteria. The findings demonstrate that the Spanish and Cleveland isolates are clonally related and suggest that this antibiotic resistant clone of serotype 23F S. pneumoniae has spread intercontinentally from Spain to the United States.

Bacterial Proteins↗
PubMed1991

[The treatment of hyperkalemia with salbutamol].

For several years now, it has been known that the administering of adrenergic beta antagonists, especially of the beta-2 type, induce hypokalemia as a result of the entering of potassium into the skeletal muscle cells. This fall in kalemia occurs independently from the effect of insulin, aldosterone or kidney excretion, is mediated by the beta-2 receptors and require the intervention of cAMP joined at the cell membrane and the subsequent stimulation of the Na-K-ATPase which bring the potassium into the striated muscle cell. Among the most outstanding drugs with beta-2 effect is salbutamol, which maintains the hypokalemic effect whether administered intravenously or inhaled. It has been used in cases of hyperkalemia, in both children and adults. The initially used intravenous dosage (0.5 mg) caused several side-effects, especially rapid heart beat, seen more in children. It has been recently found that the use of doses as low as 4 micrograms/kg lower the kalemia to values averaging 1.4 to 1.6 mEq/L (mmol/L); in addition, using these dosages intravenously in an average of 20 minutes, no side-effects were seen, even when administered to newborns. For the above, we considered that salbutamol, in the suggested dosages, constitutes an efficient and secure therapeutic method for the initial treatment of severe hyperkalemic patients.

Albuterol↗
PubMed1991

Effect of long-term n-butanol ingestion on rat brain polypeptide synthesis directed by endogenous messengers.

Long-term ingestion of sublethal n-butanol doses by rats led to a noteworthy increase in the resistance of in vitro brain ribosomal function to the acute inhibitory action of ethanol and isopropanol. Withdrawal of n-butanol did not change this adaptation process immediately. The step affected seems to be the elongation of polypeptide chains. The dependence of in vitro translation on incubation temperature was affected by the adaptation process, the translation system of chronic animals being less stimulatable than that of control animals at low temperature.

1-Propanol↗
PubMed1990

Oxidation of coniferyl alcohol by cell wall peroxidases at the expense of indole-3-acetic acid and O2. A model for the lignification of plant cell walls in the absence of H2O2.

The oxidation of coniferyl alcohol (CA), a lignin precursor, by cell wall peroxidases may take place at the expense of indole-3-acetic acid (IAA) and O2, and in the absence of H2O2. The peroxidase-catalyzed oxidation of CA shows an optimum at an IAA concentration of 0.33 mM, while higher IAA concentrations are inhibitory. The observation that the oxidation of CA by cell wall peroxidase at the expense of IAA and O2 is inhibited by genistein, a putative endogenous inhibitor of lignification in lupin hypocotyls, supports the view that the H2O2-generating system coexists with cell wall peroxidase activities involved in lignification, and that it takes place at the expense of IAA and O2.

Cell Wall↗
PubMed1990

Zymographic screening of plant peroxidase isoenzymes oxidizing 4-hydroxystilbenes.

A zymographic assay is described for the detection of peroxidase isoenzymes oxidizing 4-hydroxystilbene following isoelectric focusing. The assay is based on coupling intermediate products of the oxidation of 4-hydroxystilbene with 4-aminoantipyrine, with resultant formation of dye complexes. Control experiments in the absence of 4-hydroxystilbene and hydrogen peroxide demonstrate the peroxidative nature of the 4-hydroxystilbene-dependent dye reaction.

Ampyrone↗
PubMed1990

Identification of atypical strains of Streptococcus pneumoniae by a specific DNA probe.

A specific DNA probe containing a 0.65 Kb fragment coding for the aminoterminal region of the major pneumococcal autolysin (amidase) was constructed, deleting the region involved in the specific recognition of cell wall choline residues. The high specificity of this probe was demonstrated in tests with Streptococcus pneumoniae related species including Streptococcus oralis, which contains choline in its cell wall. The probe was used to characterize pneumococcal isolates showing atypical responses in conventional identification tests. The hybridization obtained with 27 atypical pneumococci and 11 of 17 isolates presumptively identified as viridans streptococci confirmed that the probe is suitable for diagnostic use.

DNA Probes↗
PubMed1990

A spectrophotometric assay for quantitative analysis of the oxidation of 4-hydroxystilbene by peroxidase-H2O2 systems.

A new and sensitive spectrophotometric assay has been developed to study and to characterize kinetically the oxidation of 4-hydroxystilbene (an analogue of the putative viniferin precursor, trans-resveratrol, directly involved in the resistance mechanism of the grapevine to fungal diseases) by peroxidase-H2O2 systems. The technique measures the overall increase in absorbance at 248 nm in the reaction media, probably due to the formation of a phenoxy radical of the 4-hydroxystilbene (4-HS). This technique was developed by using the purified isoenzyme C of horseradish peroxidase and all the validity criteria (sensitivity and reproducibility) were checked. The results show that it is especially suitable for low activity measurements. It was finally applied to the determination of the oxidation rate of 4-HS by peroxidases isolated from the media of suspension-cultured grapevine cells, at two different developmental stages.

Fruit↗
PubMed1990

Thirty years' experience with biliary tract reconstruction by hepaticoenterostomy and transhepatic T tube.

This study shows long-term results of biliary tract reconstruction in cases of high stenosis of the hepatic duct. Hepaticoenterostomy was performed with transhepatic insertion of a T tube following an original technique. A portion of the horizontal limb of the T tube is placed in the left hepatic duct, the other portion in the duodenum or jejunum, and the vertical limb extends into the right hepatic duct and the right lobe of the liver and is brought out through the abdominal wall. This tube is irrigated daily and removed after 12 months in order to keep the stent in place for a sufficient duration to prevent stenosis. This technique was used in 45 patients who underwent operations from 1954 to 1984. There were 6 postoperative deaths. Of the 39 patients discharged from the hospital, 37 were followed up. Excellent results were obtained in 30 patients who remained asymptomatic after observation from 1 to 14 years. In three patients, results were good, but there were occasional episodes of fever that subsided with antibiotics; one of these patients was observed for 17 years. Results were poor in four patients who developed a recurrent stenosis; three of them underwent reoperations, with satisfactory results. Long-term observation has shown that the described surgical procedure is useful in cases of high stenosis of the hepatic duct, because a stent can be left in place for a year and usually will prevent stenosis at the biliary intestinal anastomosis.

Adult↗
PubMed1990

Differential D-glucose requirements of the general amino-acid permease and protein synthesis in Saccharomyces cerevisiae var. ellipsoideus.

The dependence of the general aminoacid permease and protein synthesis on the availability of D-glucose as energy source was studied. Stimulation by the sugar was immediate once added to the cell suspensions and seems to be mediated by energy derived directly from glycolysis. The general aminoacid permease was saturated linearly with D-glucose whereas protein synthesis was saturated sigmoidealy requiring much higher concentration of the sugar than the general aminoacid permease.

Amino Acid Transport Systems↗
PubMed1990

[Nutritional utilization of a low protein diet in alloxan diabetic rats].

Dietary control is known to influence diabetic processes. Therefore, the purpose of this work was to determine possible effects brought about by two different dietary protein levels on the nutritional diet utilization in alloxan-diabetic rats. Rats were divided in two groups: 1) One fed on 12% and 2) one a 4% protein diet. Each group was then divided into two subgroups: A) non diabetic and B) diabetic. Weight parameters, food intake, food efficiency (FE), digestive efficiency (DE), metabolic utilization (MU), retained N/ingested N ratio as well as initial and final glycemia were evaluated at the beginning and at the end of the experiment. A decrease in body weight, FE, DE and MU was observed in the control rats of group 2A, in comparison with the group 1A. Experimental diabetes led to increased FE in 1B group in relation to those of group 1A. Also decreased body weight and FE as well as increased food intake and DE were found in the control animals of 2B group. Glycemia increased in diabetic rats as compared with non-diabetic rats, in both groups, 1 and 2. The data suggest that under the experimental conditions cited, both the nutritional utilization of the diet and the diabetogenic status might be modulated by the dietary protein ingested level.

Alloxan↗
PubMed1990

Messenger-dependent action of guanylylimidodiphosphate and translation inhibitors on rat brain polypeptide synthesis.

The effects of the Guanosine 5'-triphosphate analog guanylylimidodiphosphate and several antibiotics on protein synthesis in a cell-free system from rat brain were investigated as a function of the template used. Polypeptide chain elongation was promoted by the analog only in the system coded by the endogenous template but not when coded by polyuridylic acid. The effects of the antibiotics were also dependent on the template used. This suggest that the template conditioned the ribosomal conformation which determine the inhibitory effect of the antibiotics.

Animals↗
PubMed1990

Influence of the structure of alkanols on their inhibition of protein synthesis in Saccharomyces cerevisiae var. ellipsoideus.

The effects of several short chain alcohols on protein synthesis by intact Saccharomyces cerevisiae var. ellipsoideus cells were studied. The results show that the relative inhibitory potencies correlate well with the size of the carbon backbone, thus suggesting that a hydrophobicity-related effect is involved in the inhibitory action of these alcohols. Additionally, the branching nature of the carbon backbone contributes to determining the action of the alcohol, as proved by the relative potencies of the four-carbon alcohol series.

Alcohols↗
PubMed1990

[Infarct size determination using enzymatic methods in patients with early coronary recanalization].

To evaluate the usefulness of the infarct size determined by serial creatine kinase (CPK) measurements in patients with early reperfusion, we have studied 189 patients meaning in age 59.2 +/- 8.6 years, with acute myocardial infarction treated with streptokinase (STK); 81 of them by intracoronary route (group A), and 108 by intravenous administration (group B). In the group A we performed serial angiographic studies in the following conditions: baseline, immediately after STK infusion and before hospital discharge. In group B we performed only one angiographic control 5 +/- 3 days after. In patients with reperfusion, the parameters of left ventricular function correlated with cumulative creatine kinase release (MAX-CPKr) by linear regression in both groups. We observed a tendency to closer correlations in patients with left anterior descending or circumflex artery as the infarct related artery, in patients without previous infarction and in those who did not receive electrical shock for ventricular arrhythmias. In patients with unsuccessful reperfusion (n = 11), we also obtain a significant correlation (r = 0.72) between ejection fraction and MAX-CPKr. The slope of the regression line (b = 7.7 X 10(-5) was steeper (p less than 0.05) than that observed in recanalized patients, who were evaluated within the first 3 days (b = 2.2 X 10(-5), after 8 +/- 5 days (b = 2.7 X 10(-5), or before discharge, at 22 +/- 9 days (b = 2.6 X 10(-5).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

The spectrophotometric determination of indole-3-methanol in small samples with p-dimethylaminocinnamaldehyde on the basis of the formation of an azafulvenium salt.

Indole-3-methanol is coupled, at acidic pH, with p-dimethylaminocinnamaldehyde to give a highly colored azafulvenium salt. IR, 1H NMR, and mass spectroscopic evidence indicates that this azafulvenium salt is the 2-[3'-(p-dimethylaminophenyl)-2'-propenyliden]-3-hydroxymethyl-2H- indolenine hydrochloride. This reaction led us to elaborate a rapid colorimetric assay for quantitative determination of indole-3-methanol formed by peroxidases as the product of oxidation of the plant growth regulator indole-3-acetic acid.

Aniline Compounds↗
PubMed1989

[Usefulness of determining 2 cell membrane enzymes in bronchial aspirate and lung tissue in patients with cancer of the lung].

The cell membrane enzymes, Alkaline Phosphatase and Gamma Glutamyl Transferase, have been studied in lung aspirates from healthy subjects and lung cancer patients. These enzymes were studied, in the latter, both in healthy and in neoplastic tissue. The enzymatic activity both in the lung aspirate and in the neoplastic tissue was significantly lower in poorly differentiated cancers when compared to well or moderately differentiated tumors. Similarly, analysis revealed that there was a statistically significant decrease in the activity of both enzymes in lung aspirates from patients with bronchogenic tumors when compared to healthy controls. The results obtained in this present work, together with the easiness of obtaining a lung aspirate suggest that these enzymes should be determined in order to obtain further information about the histological origin of lung cancer. These enzymatic changes could be explained with the "fatalism" theory for neoplastic tissue as we explain in this work.

Alkaline Phosphatase↗