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O Muñoz

Publications and source records attributed to O Muñoz.

At least 73 records · Page 4Linked to original sources
PubMed1991

[Diagnosis of streptococcal pharyngo-tonsillitis: clinical criteria or coagglutination?].

With the purpose of evaluating the usefulness of clinical data and a coagglutination test for the diagnosis of streptococcal pharyngeal tonsillitis, a study was carried out comparing both methods with the standard pharynx culture (gold standard). One hundred and forty-one patients clinically diagnosed with pharyngeal tonsillitis were analyzed. 80 other patients diagnosed with rhino-pharyngitis were used as control groups as well as a group of 66 healthy patients. It was found that the presence of pus in the tonsils and the absence of rhinorrhea and/or a productive cough were isolated clinical variables which showed a significant difference when comparing those cases with a positive or a negative culture (P less than 0.01). These clinical data had a sensitivity and adequate negative predictive values (68 to 83% and 90 to 92%, respectively); specificity was 44 to 74% and the positive predictive value from 24 to 36%. The gathering of combined clinical indexes with different symptoms and signs, were not greater than isolated data. The coagglutination test in those cases of pharyngeal tonsillitis showed greater better specificity (98%) and positive predictive value (93%), but saw no improvement in sensitivity (72%) nor in the negative predictive value (91%), which is why when faced with a negative coagglutination test, it is still necessary to perform a throat culture due to the risk which the patient may be exposed to when no treatment is given. The analysis of the advantages and disadvantages in the routine use of coagglutination and cultures in their particular cases, allows us to conclude that in daily clinical practice the use of clinical criteria is of greater usefulness.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Pathogenic and non-pathogenic zymodemes of Entamoeba histolytica in a rural area of Mexico. Concordance with serology.

OBJECTIVES: a) to describe the frequency of pathogenic and nonpathogenic zymodemes of E. histolytica in asymptomatic carriers in rural Mexico, b) to identify the isoenzymatic pattern of the zymodemes and c) to measure the concordance of pathogenic zymodemes and positive serology. DESIGN: Descriptive cross-sectional survey. Reference population: rural communities of the mexican highlands. STUDY UNITS: 2048 individuals from 341 families of 5 rural communities. METHODS: From the local census of each community, 70 to 100 families were selected by random sampling. All members of each family were studied. After obtaining the consent the following activities were done: a) filling of a questionnaire about housing and sanitary condition and structure of the family; age, sex, literacy and digestive symptoms and illness during the previous 4 weeks, in each individual; b) a blood sample for serology (CEIP and IHA) and c) a stool sample for coproparasitoscopic analysis (CPS) and zymodemes identification, in each individual. Statistical evaluation was done by kappa index and receiving operating curves (ROC). MAIN RESULTS: there were 122/1730 (7.1%) CPS studies positive to E histolytica cysts, 100/1730 (5.8%) zymodemes isolated and 137/1886 (7.3%) positive serologic studies. Of the 100 zymodemes 30 had a pathogenic pattern, three had a mixture (pathogenic/nonpathogenic) and 67 had a non-pathogenic patterns. There were two (XVII, XVIII) patterns described for the first time in Mexico. Concordance between pathogenic zymodemes and positive serology (IHA greater than 1:128) was very low, Kappa = 0.05. ROC curves for IHA in pathogenic and non-pathogenic zymodemes showed little relationship between positive serology and pathogenic pattern. CONCLUSIONS: Although the frequency of positive serology, coproparasitoscopic studies and zymodemes identification was similar, the concordance between serology and the coprologic studies was very low. This disagrees with other reports, and deserves further investigation using methodologic standards in design.

Animals↗
PubMed1990

Study of human Entamoeba histolytica infection by zymodeme, indirect hemagglutination and electroimmunotransfer blot assays.

Human amebiasis is a parasitic infection which involves asymptomatic as well as intestinal and extraintestinal symptomatic stages in individuals harbouring Entamoeba histolytica. Several factors have been proposed to explain the variability in the outcome of the disease. Among these are differences in virulence of E. histolytica strains and methods such as zymodeme analysis have been used to differentiate invasive from non invasive strains of this parasite (Sargeaunt and Williams, 1978). In order to establish a possible correlation between zymodeme analysis and serological data in human cases of amebiasis, a cross-sectional epidemiological study was carried out in the community area of Cadereyta, State of Queretaro, Mexico. In this study, fecal and serum samples from individuals were also tested by Indirect Hemagglutination assay (IHA) to determine antibody titre and by a standardized Electroimmunotransfer blot assay (EITB) for recognition of E. histolytica specific antigens. Zymodemes were determined in a total of 81 samples. Of these, 27 had a pathogen zymodeme (PZ) while 54 had a non pathogen zymodeme (NPZ). Values obtained by IHA varied from negative to titres up to 1:256 in serum samples tested. Reactivity to E. histolytica antigens determined by EITB was observed in all sera. Patterns of antigen recognition were complex and showed reactivity to several parasite molecules. Among these, components with M. Wt. of 165, 119, and doublets of 98-100 and 50-52 Kd were more frequently recognized by antibodies present in the sera tested. In general, antibody titres detected by IHA did not showed a direct correlation with zymodeme analysis. Samples with PZ or NPZ had similar variable levels of reactivity to E. histolytica antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[In vitro sensitivity of Entamoeba histolytica to metronidazole].

The chemotherapy of amebiasis includes different substances with intra and extraintestinal action. Nowadays, metronidazole is the election drug by its high efficacy and low toxicity. Some therapeutic failures with metronidazole in patients with invader amebiasis and some reports of resistance to it, of certain strains of Trichomonas vaginalis and species of Bacteroides have caused an increased interest to do new in vitro evaluation of this compound and to search of new antiamebic drugs. The object of this work was to standardize with our conditions a microtechnique to evaluate the sensibility to metronidazole, experimented by trophozoites of three amebic strains of different virulence (HK9:NIH, HM1:IMSS, HM3:IMSS) and to compare the effect exerted by the drug on them. We modified the technique proposed by Cedeño and Krogstad in 1983. First we read the results in a half of the time employed by them (24h) and after, we fixed the trophozoites with 0.25% glutaraldehyde before of make the counts of them. We compared the number of cells in microcultures of 3.2 x 10(4) trophozoites incubated during 24h with metronidazole (from 0.008 to 1 micrograms/ml) with the obtained in control microcultures. Each one of the strains showed to have a characteristic sensibility to the drug (p less than 0.001), which was directly proportional to the concentration. The middle effective dose of HK9 and HM1 strains was 0.3 microgram/ml and of 1 microgram/ml for HM3 strain. This technique seems to be reproducible and could be useful to quantify the in vitro activity of antiamebic agents.

Animals↗
PubMed1990

Evaluation of an immunoblot methodology for the detection of relevant Entamoeba histolytica antigens by antibodies induced in human amebiasis.

The complexity of the clinical spectrum in human amebiasis and the high variability in laboratory methods used to detect Entamoeba histolytica infections have impeded the collection and evaluation of reliable epidemiological data. Thus, more sensitive, specific and standardized methods are needed in order to accurately identify infections with this parasite. An important step in the development of serological diagnostic methods is the identification and isolation of specific parasite antigens which are immunogenic in the host. In this work, we have standardized an electroimmunotransfer blot technique to characterize E. histolytica antigens recognized by antibodies present during human amebic infections. An important aspect was an investigation of technical variations in the preparation of cell lysates including the use of different protease inhibitors and solubilizing agents. The highest yield of protein was achieved by homogenization of trophozoites in the presence of 10 mM p-hydroxymercuribenzoate (pHMB) as a protease inhibitor and by lysis using Triton X-100 and a mixture of protease inhibitors. Recovery of degraded vs non-degraded proteins in the cell extracts was evaluated by gradient polyacrylamide gel electrophoresis. Both quantitative and qualitative differences were noted between the different methods of preparing soluble cell extracts. A more complete set of antigenic components was obtained by homogenization and use of pHMB. Thus parasite extracts prepared by this method were selected for protein transfer. In this, the optimal protein concentration was of 120 micrograms of protein per cm of gel width and efficient transfer of proteins to nitrocellulose sheets was achieved at 100 V for 2 hrs and at 4 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Detection of furazolidone in human biological fluids by high performance liquid chromatography.

Furazolidone has normally been administered as a non-absorbable antimicrobial agent for use in gastrointestinal infections. However, in India and Mexico it has been used successfully for the treatment of typhoid fever. We measured concentrations of furazolidone by high performance liquid chromatography (HPLC) in several biological fluids, after a single oral dose (5 mg/kg). Six healthy adult volunteers and seven children with typhoid fever and ten children with purulent meningitis were studied. In adults the peak serum concentration was less than or equal to 0.84 mg/l and less than or equal to 4.78% of the ingested dose was excreted in the urine. In the children concentrations were similar to those found in volunteers. The cerebrospinal fluid/serum ratio ranged from 1.02 to 5.95 in the meningitis patients. HPLC is a rapid and sensitive method for the quantitation of furazolidone in biological fluids. The minimum detectable concentration was 0.05 mg/l, with a precision of 6% from peak area and an average recovery of 98%.

Adolescent↗
PubMed1984

Prevalence of Clostridium difficile and its cytotoxin in infants in Mexico.

The incidence of Clostridium difficile and its cytotoxic activity were determined in the feces of 122 children under 1 year of age. Samples were obtained from children receiving antibiotics and with (52 cases) or without (26 cases) diarrhea, from children with diarrhea who did not receive antibiotics (22 cases), and from healthy children (22 cases). Isolation of C. difficile in feces from children in all groups was similar (mean 23.4%) except for the group with non-antibiotic-associated diarrhea (4.5%). In both groups of children receiving antibiotics, with or without diarrhea, the cytotoxin was detected in 7.6% of the cases. In the group with non-antibiotic-associated diarrhea, none of the samples was positive for cytotoxicity. In healthy children, cytotoxin was positive in 4.5% of the cases.

Anti-Bacterial Agents↗