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Biomedical subjects

O Muñoz

Publications and source records attributed to O Muñoz.

At least 55 records · Page 3Linked to original sources
PubMed1996

Improving physician prescribing patterns to treat rhinopharyngitis. Intervention strategies in two health systems of Mexico.

To improve prescribing practices for rhinopharyngitis, an interactive educational intervention and a managerial intervention were carried out in 18 primary care facilities in metropolitan Mexico City. Four family medicine clinics of the Mexican Social Security Institute (IMSS) and 14 health centres of the Ministry of Health (SSA) were included. A quasi-experimental design was employed. One hundred and nineteen physicians (IMSS 68, SSA 51) participated. Sixty-five physicians (IMSS 32, SSA 33) were in the study group, while 54 were in the control group (IMSS 36, SSA 18). The study had four stages: (I) baseline, to evaluate the physicians' prescribing behaviour for rhinopharyngitis; (II) intervention, using an interactive educational workshop and a managerial peer review committee; (III) post-intervention evaluation of short-term impact; and (IV) follow-up evaluation of long-term effect 18 months after the workshop. The control group did not receive any intervention but was evaluated at the same time as the study group. At baseline, most patients in both institutions received antibiotic prescriptions (IMSS 85.2%, SSA 68.8%). After the workshop, the percentage of patients receiving antibiotic prescriptions in the IMSS went from 85.2% to 48.1%, while in the SSA it went from 68.8% to 49.1%. Appropriateness of treatment was analyzed using the physician as the unit of analysis. At baseline, 30% of IMSS physicians in the study group treated their patients appropriately. After the intervention, this percentage increased to 57.7%, and at the 18-month follow-up it was 54.2%. The SSA study group increased the appropriate use of antibiotics from 35.7% to 46.2%, with this percentage falling to 40.9% after the 18-month follow-up period. In the control group there were no significant changes in prescribing patterns with respect to either the prescribing of antibiotics or the appropriateness of treatment. The intervention strategies were successful in both institutions. Forty per cent of physicians improved their prescribing practices after the workshop, with this change remaining in 27.5% of them throughout the follow-up period. On the other hand, 42.5% of the physicians did not change their prescribing practices after the intervention. The rest (17.5%) showed appropriate prescribing practices during all the stages of the study. We conclude that it is possible to improve the physicians' prescribing practices through interactive educational strategies and managerial interventions. This type of intervention can be an affordable way to provide continuing medical education to primary care physicians who do not have access to continuing educational activities, and to improve the quality of care they provide.

Adult↗
PubMed1995

Observer variability in the process of medical care for amebic liver abscess.

The objectives of this study were to evaluate the degree of concordance between specialists (physicians) in relation to the process of medical care of patients with amebic liver abscess and to elaborate a model that contains the minimum elements considered as indispensable for the diagnosis, treatment and follow-up of an illness, based on the consensus of physicians that usually treat these patients. The design of the study was a comparative survey. Twenty eight specialists (physicians) were interviewed (nine infectologists, two gastroenterologists, six internists and eleven general surgeons) affiliated with second and third level hospitals (medical centers) of the Instituto Mexicano del Seguro Social (Mexican Institute of Social Security) located in the southern part of Mexico City. A three-part structured questionnaire was applied: the first part consisting of 57 questions focused on the diagnosis, the second corresponded to treatment and consisted of 16 questions and the third part referred to follow-up and included five questions. The agreement among the internists for the overall process (diagnosis+treatment) was the highest (kappa (k) = 0.64), followed by the surgeons (k = 0.63) and the infectologists (k = 0.49); the difference among these three groups of specialists was considered statistically significant (p = 0.001). When the therapeutic process was analyzed in separated form, this same statistical difference was sustained, which on the other hand was not identified for the diagnosis and follow-up processes. When comparing each group, the degree of agreement obtained from the members of each group did not express statistically significant differences.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Inappropriate treatment in children with bloody diarrhea: clinical and microbiological studies.

It is suggested that in dysentery physicians should treat empirically, as early treatment seems to improve outcome. A constantly updated knowledge of the relative frequency of enteropathogens and their sensitivity to antimicrobials is needed to choose the right therapy. We studied microbiological and clinical findings in 119 children with bloody diarrhea in Mexico City. Patients were divided into those < 1 year (infants) and those 1-5 years (children). Shigella was more frequent in children (35%) than in infants (10%). Campylobacter was more common in infants (29%) than in children (12%); Salmonella more frequent in infants (22%) than in children (8%); cytotoxic E. coli (EHEC) more frequent in children (20%) than in infants (13%). No cases of amebiasis were identified. Fever was the most sensitive indicator of infection for Shigella (70%), as compared for Salmonella (50%), Campylobacter (42%) and EHEC (36%); whereas specificity was about 50% for all pathogens. In contrast, the absence of fever was 80% predictive for the absence of these pathogens. In children with dysentery, the specific etiology cannot be predicted in the absence of culture. Almost 50% of the Shigella, Salmonella and EHEC isolates were resistant to ampicillin. In our community, the use of ampicillin and metronidazole should be discouraged.

Anti-Infective Agents↗
PubMed1995

Archives of Medical Research: an historical and subject coverage overview.

A bibliometric study about the subject content of the articles published in the Mexican scientific journal Archives of Medical Research is reported. The journal, published by the Mexican Institute of Social Security (IMSS), is comprised of 100 regular issues and 12 special supplements giving a total amount of 1,424 reports on medical research performed in Mexico during the last 25 years. According to the type of studies published during this period, we found that there is a similar percent of biomedical and clinical reports in the journal (47 and 42%, respectively) and a low proportion of epidemiological and medical educational reports (8 and 3%, respectively). Six thematic areas of research have been permanently published in this journal: investigations on infectious and neurological diseases being the areas mainly represented (34% of the total, corresponding to 17% in each area), followed by studies in reproductive biology (10%) and endocrine (7%), oncological (5%) and cardiovascular (3%) diseases. The tendency of the subjects covered by the journal during this period shows an increment in reports on infectious and parasitic disorders together with an increase in publications related to medicinal plant pharmacology; reproductive biology and endocrine studies show also an increasing tendency. On the other hand, a moderate decrease in studies related to neurological, oncological and cardiovascular diseases is observed. The origin of contributions during the last five years has balanced the proportion of papers published from IMSS scientists, other Mexican biomedical researchers and foreign contributions, thus reflecting favorably the recent changes in the journal's policies. This journal represents a clear example of a scientific publication edited in a developing country, originating as a national publication that evolved progressively into an international biomedical journal.

Animals↗
PubMed1995

From research to public health interventions. I. Impact of an educational strategy for physicians to improve treatment practices of common diseases.

Errors in treating common diseases occur very frequently in primary health care practice. While many of these mistakes are not life-threatening, the costs of abuse in drug prescription may be greatly increased. An educational strategy aimed to improve physicians' prescribing practices for acute diarrhea (AD) and acute respiratory infection (ARI) was developed as a research study, involving three medical care units. The strategy was largely based on promoting active participation of the trainees in the whole process, including: (a) group participation in a literature review of updated articles related to management of AD and ARI; (b) analysis of prescribing practices before the intervention; (c) participation in the development of a clinical algorithm for the therapeutic management of these illnesses; and (d) discussion of the usefulness of the algorithm during peer review committee meetings. Successful results of this intervention, as judged by the improvement of treatment practices and the persistence of changes for up to 2 years after the intervention, as well as its ease of application and low costs, motivated its extension to a health District and a State. In these sites, the intervention was in charge of medical leaders from the clinics and medical heads of the local health systems, respectively. The extension of the educational strategy was accompanied by a relative reduction in AD from 46.7% to 6.5% and in ARI from 32.6% to 8.5%. However, the benefit-cost ratio showed a dramatic increase when comparing results from the research study and from the State intervention, for both AD (from 3.3 to 4.4) and ARI (from 16.2 to 21.6), for an overall net increase of 33.3%. Based on these results, the educational strategy was adopted by the National Program for the Control of Diarrheal Diseases, and was used to train public health physicians throughout the country, from 1992 to 1994.

Acute Disease↗
PubMed1995

Indirect immunofluorescent assay (IFA) in buffy coat as a rapid diagnostic test for invasive candidiasis.

In order to have a diagnostic test for invasive candidiasis, an immunofluorescent assay (IFA) in buffy coat was developed and evaluated. This test was compared to buffy coat culture and blood culture. The study was divided into two parts: evaluation of the diagnostic test in a rabbit model, and for diagnosis in patients at high risk for invasive candidiasis. Part I: Rabbits were experimentally infected. Of 13 rabbits with disseminated candidiasis blood was drawn from central venous catheter and from peripheral veins. From catheters, Candida was detected in 13/13, 10/13 and 8/13, by buffy coat culture, IFA, and blood culture, respectively. From peripheral veins, Candida was detected in 10/10 by buffy coat cultures, in 6/10 by IFA and in 3/10 by blood cultures. The gold standard was histopathological diagnosis; sensitivity for IFA was 60% with peripheral blood and 76% with catheter blood samples. Part II: IFA and blood cultures were compared in clinical samples from hospitalized children. Forty patients were included. Candida was isolated from blood cultures in four patients whereas IFA detected Candida in 22 patients. Differences were statistically significant (p < 0.05). We conclude that IFA in buffy coat smears is a reliable test to detect candidemia, and would be a useful tool to help physicians with treatment decisions with amphotericin B.

Animals↗
PubMed1994

Changing physician prescribing patterns: evaluation of an educational strategy for acute diarrhea in Mexico City.

This paper presents the results of an intervention strategy designed to decrease drug prescription and increase the use of oral rehydration therapy (ORT) in the treatment of acute diarrhea aimed at family medicine practitioners in two primary health care units of the Mexican Social Security Institute. The intervention consisted of six successive stages: 1) Baseline study of prescribing practices by all 69 physicians in both clinics; 2) Training workshop attended by 36 physicians, including a critical analysis of relevant up-to-date literature, review of results of stage I, discussion of a previously designed treatment algorithm for acute diarrhea, and modification of it according to participant's experience; 3) Post-workshop evaluation; 4) Establishment of a peer review committee to discuss the treatment behavior of participating physicians; 5) Mid-term evaluation for 2 months after the committee stopped functioning; 6) Long-term evaluation at 6, 12 and 18 months, of 20 physicians who received the complete intervention (study group) and 20 physicians who received none (control group). The treatment behaviors of the study and control groups were similar on baseline, but differed significantly (P < 0.01) in the post-workshop evaluation. The study group showed a reduction in the use of antibiotics (from 78.8% to 39.3%) and restrictive diets (47.3% to 12.4%), and increased the use of ORT (31.4% to 58.4%) for children younger than 5 years old with acute diarrhea. In the mid-term evaluation, the use of antibiotics by the study group decreased to 27.6%, prescription of restrictive diets decreased to 6.4%, and use of ORT increased to 73.8% (P < 0.01, in all cases). In the long-term evaluation, persistent positive prescribing behavior was still present in the study group, with a significant difference (P < 0.05) compared to the control group, where no modification was found in the prescribing behavior throughout the study. The average proportion of cases treated according to the algorithm by the study group increased in 29.2% (31.3 to 60.5%) after the workshop, and 45.2% (31.3 to 76.5%) after peer review committee. This behavior was maintained during 18 months after the intervention (74%). The control group showed no significant modification in the average proportion of cases treated according to the algorithm during the study (2 years 7 months). The active participation of physicians in the workshop and in the peer review committee was identified as the key to the short and long-term success of the educational strategy.

Acute Disease↗
PubMed1993

Entamoeba histolytica: antibody response to recent and past invasive events.

Sero-epidemiological data from endemic amoebiasis areas are difficult to evaluate because the serology of individuals affected by an active process of Entamoeba histolytica tissue invasion is, at present, almost impossible to distinguish from that of individuals who have had an invasive event in the past. The present study compares serum antigenic recognition frequencies among three groups of individuals with different infective conditions: amoebic liver abscess patients; asymptomatic cyst passers; and individuals who have had amoebic liver abscess from one to three years before the study. Control groups consisted of Mexican and Canadian healthy adults. Western blots of E. histolytica membrane extract antigen were reacted with sera from the studied individuals, recognition frequency values were calculated and immunoplots of frequency differences were constructed. The results obtained suggest that the identification and purification of antigenic fractions, which are frequently recognized by sera of amoebic liver abscess patients (136, 132, 93, 70 and 62 kDa), or preferentially associated with past invasive events (144, 140 and 49 kDa), or related to the E. histolytica cyst passer condition (62 and 136 kDa), are important improvements in the use of serology for diagnosis and epidemiological studies in endemic areas of amoebiasis.

Adult↗
PubMed1993

Production of cytotoxins and enterotoxins by strains of Shigella and Salmonella isolated from children with bloody diarrhea.

The role of toxins in the pathogenesis of bloody diarrhea caused by Shigella and Salmonella isolated from children with bloody diarrhea was studied for production of toxins active on cells in culture and in rat intestinal loops. Human epithelial cells from colon carcinoma (HT-29), Chinese hamster ovary cells (CHO) and kidney fibroblast from rhesus monkey (Vero) were used to detect cytotoxins. On HT-29 almost 50% of the Shigella and about 20% of the Salmonella strains caused rounding of cells; on CHO over 50% of Salmonella and 20% of Shigella strains caused elongation of cells, some strains caused also rounding of these cells whereas on Vero over 60% of Salmonella and 40% of Shigella strains caused rounding of cells. Cytotoxicity on Vero and CHO cells was strongly inhibited with cholera toxin antiserum, whereas that on HT-29 was inhibited with C. difficile toxin B antiserum. Cytotonic activity on CHO cells and rounding on Vero cells seem to be suitable models to detect toxins cross-reacting with cholera toxin. Both species, Shigella and Salmonella, produce cytotoxins and enterotoxins which could play a role in intestinal disease.

Animals↗
PubMed1993

Antisecretory activity in a lectin fraction of plasma from patients with acute diarrhea.

The present study describes the first attempt to detect antisecretory activity in a lectin fraction of plasma from patients with acute diarrhea. The plasma antisecretory protein (ASP) was purified by affinity chromatography in agarose, and its antisecretory activity tested in rats subjected to intestinal challenge with cholera toxin. During the first 24 h of the diarrheal episode, antisecretory activity in patients (median 0, range 0-25%) was lower than that seen in the asymptomatic group (median 10, range 0-30%); 3 days later, when diarrhea ceased in most of the patients, the ASP activity increased significantly (median 30, range 0-75%). However, 5 days later the activity decreased again (median 0, range 0-55%). No differences in ASP levels were found between cases associated with an enteropathogen and those where no pathogen was identified. These findings reveal an inverse relationship between the increase in ASP and the patient's intestinal secretion; suggesting that ASP plays a role in the compensatory mechanisms that occur in diarrhea in humans.

Acute Disease↗
PubMed1992

Antitumor effect and toxicity of two new active-site-directed irreversible ornithine decarboxylase and extrahepatic arginase inhibitors.

The irreversible ornithine decarboxylase and extrahepatic arginase inhibitors (+)-S-2-amino-5-iodoacetamidopentanoic acid (2-AIPA) and (+)-S-2-amino-6-iodoacetamidohexanoic acid (2-AIHA) were evaluated. The LD50 tests were made in rats and mice using both compounds. Rats and mice were treated with either 2-AIPA or 2-AIHA i.p. for a period of 180 days. The treated animals showed a decrease of total serum proteins and increased ALT and AST levels. CK was also modified but inversely related to dose. Protection tests were carried out using L5178Y mouse lymphosarcoma. The mean survival time for each treated group was calculated and the percentage T/C was determined. For 2-AIPA it was 170 and for 2-AIHA it was 210 at 15 mg/kg.

Amino Acids↗
PubMed1992

Sensitivity in culture of epithelial cells from rhesus monkey kidney and human colon carcinoma to toxins A and B from Clostridium difficile.

The effect of toxins A and B from Clostridium difficile on human colon carcinoma cells (HT-29, epithelial), rhesus monkey kidney cells (MA-104, epithelial) and green monkey kidney cells (VERO, fibroblast) was studied. Both toxins caused rounding of HT-29 cells and rounding with projections remaining attached to the substrate in MA-104 and VERO cells; however, the sensitivity to each toxin varies considerably. Toxin A was detected in ng by VERO, pg by HT-29 and fractions of pg by MA-104 cells; for toxin B, pg were detected by VERO, ng by MA-104 and micrograms by HT-29 cells. HT-29 cells were grown with galactose to allow their differentiation to enterocytes, and their sensitivity to the toxins during the process was studied. At early stages, the sensitivity to both toxins was similar, and as the differentiation proceeded, the response to both toxins decreased continuously, and after 16 days no evident morphological effect was observed, even with micrograms amounts of either toxin. In contrast to all cell lines reported to date, HT-29 and MA-104 epithelial cells are exquisitely sensitive to toxin A and less responsive to toxin B. The rounding of HT-29 by these toxins depends on the degree of differentiation of the cell.

Animals↗
PubMed1992

In-vitro susceptibility of Giardia lamblia to albendazole, mebendazole and other chemotherapeutic agents.

The susceptibility of a strain of Giardia lamblia to benzimidazole carbamates, 5-nitroimidazoles, nitrofurans and other drugs was studied in vitro. Albendazole was the most active compound, with a 50% inhibitory concentration (IC50) of 0.01 mg/L and a minimal lethal concentration (MLC) of less than 0.04 mg/L; the IC50 of mebendazole was 0.06 mg/L and the MLC less than 0.5 mg/L. Among the 5-nitroimidazoles tested, ornidazole was the most effective (IC50 0.12 mg/L); tinidazole, metronidazole, secnidazole and hemezole were less active. Nifuroxazide, etofamide and nalidixic acid exhibited modest anti-giardial activity; quinfamide did not inhibit the growth of the parasite at a concentration of 200 mg/L. Albendazole and mebendazole are promising candidates for clinical use and should be further evaluated.

Albendazole↗
PubMed1992

A rapid colorimetric assay with the tetrazolium salt MTT and phenazine methosulfate (PMS) for viability of Entamoeba histolytica.

A rapid colorimetric assay for viability of E. histolytica trophozoites using the tetrazolium salt MTT and phenazine methosulfate (PMS) was developed. The MTT is normally reduced by dehydrogenases of viable cells and transformed to formazan, a colored compound; the reaction is catalyzed by PMS. Trophozoites of E. histolytica were incubated in the presence of MTT and PMS during 15, 30, 45, 60 and 75 min, at 37 degrees C. Trophozoites killed by heat or cold were used as controls. The formazan produced into the cells was extracted with isopropanol-HCl and the optical density (OD) was measured at 570 nm. There was a linear relation between the number of viable trophozoites and the OD570 (r2 = 0.98). The trophozoites killed by cold or heat did not reduce MTT. The optimal time of incubation with MTT/PMS was 45 min. The MTT/PMS assay for determining viability of E. histolytica trophozoites is reproducible, rapid and easy to perform and it could be useful to study cytotoxicity and susceptibility to drugs.

Animals↗
PubMed1992

Lack of in vitro interference between SA-11 rotavirus and attenuated poliovirus type 1.

To determine if rotavirus interferes with the multiplication of poliovirus, and hence the efficiency of the polio vaccine, the effect of timing and concentration of Simian rotavirus (SSA-11) on polio-1 infection in MA-104 cells was studied in vitro by evaluating the cytopathic effect, the reduction of the infectivity titers and the visualization of viral particles by electron microscopy. We found that poliovirus 1 was able to replicate when the challenge dose was administered within the first 8 h following SA-11 infection and with titers ten times lower than those of rotavirus. Hence, non-interference effect was observed in this in vitro model.

Animals↗
PubMed1992

[Protection of health personnel against hepatitis B by DNA recombinant vaccine].

Hepatitis B (HVB) is a worldwide spread health problem. It has been assessed that there are more than 300 millions of carriers. HVB has a special concern for health care workers (HCW's) due to the high risk among them of getting the infection in clinic-setting areas. According to some estimation, the risk for hepatitis B among HCW's is 2 to 10 times higher than the risk for general population. The risk is related to the degree of direct contact with blood and body fluids, as well as, with the frequency of traumatic exposure in the work place. The control of this infection is based on the observance of universal precautions and the vaccination, since there is not treatment against this disease. The results of an efficacy-evaluation of DNA recombinant vaccine against hepatitis B are reported; 174 HCW's were studied; three dosages of vaccine were administered (0.1st and 6th month) by I.M. via. In addition, three serum samples were collected at 0, 1st and 9th month after vaccine administration. We did not find carriers of surface antigen of hepatitis B. With regards to seroconverted individuals we observed the following results: there were a satisfactory response to the vaccine in 163 individuals (93.7%); however, 8 (4.6%) persons did not reach titles of protective antibodies and 3 (1.7%) did not show seroconversion at all. Therefore, 11 persons (6.3% of the total) did not result immunized. The secondary reactions to the vaccines were low in frequency and mainly of local presentation. Among the study population we did not find chronic carries of hepatitis B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗