PubMed Health⌕ Search

Biomedical subjects

L Muñoz

Publications and source records attributed to L Muñoz.

At least 73 records · Page 4Linked to original sources
PubMed1998

[Prospective and comparative study between cefuroxime, ceftriaxone and amoxicillin-clavulanic acid in the treatment of community-acquired pneumonia].

Among community-acquired infections, pneumonia is still a large health problem which is of great interest mainly due its high mortality and morbidity. From 1991 to 1997, 409 patients who had been diagnosed with community-acquired pneumonia and had been admitted to the internal medicine service of a university hospital were prospectively studied. The patients were classified into three groups according to the random antibiotic treatment they had received (ceftriaxone, cefuroxime or amoxicillin-clavulanic acid). The initial characteristics of the patients with regard to epidemiology, clinical description and critical situation were similar in all the groups studied. A total of 36.9% of the cases were documented microbiologically, with the most frequently isolated pathogens being Streptococcus pneumoniae and Haemophilus influenzae. The recovery rate was 92.2% and three patients had a recurrence of pneumonia. Global mortality was 5.8%. No statistically significant differences were found in the evolution of patients treated with cefuroxime, ceftriaxone or amoxicillin-clavulanic acid, with the latter representing an empirical treatment of choice for community-acquired pneumonia.

Adolescent↗
PubMed1996

Prospective study of epidemiology and prognostic factors in community-acquired pneumonia.

Of 342 patients with community-acquired pneumonia, 100 were diagnosed etiologically. In these patients, disease epidemiology, prognostic factors, and influence of antibiotic treatment were analyzed prospectively. Fifty-two patients were treated with a broad-spectrum antibiotic (ceftriaxone), and 48 received a medium-spectrum antibiotic (cefuroxime); some patients in each group also received erythromycin. Streptococcus pneumoniae was the most frequently isolated microorganism (43%), followed by Chlamydia pneumoniae (21%), Haemophilus influenzae (19%), and Mycoplasma pneumoniae (11%). Factors significantly associated with increased mortality were initially critical or poor clinical condition, involvement of two or more lobules, and complications. Prior administration of antibiotics was predictive of penicillin and erythromycin resistance in Streptococcus pneumoniae, but had no effect on the course of the disease. Eight patients died, 89 were cured, and three had recurrences; there was no significant difference in outcome between treatment groups, regardless of whether patients also received erythromycin. Increased knowledge of epidemiological, predictive, and prognostic factors can significantly improve early diagnosis of community-acquired pneumonia and facilitate the choice of appropriate antibiotic treatment, thereby helping to reduce morbidity and mortality.

Adolescent↗
PubMed1996

Variability of cadmium, copper and zinc levels in molluscs and associated sediments from Chile.

The concentrations of cadmium, copper and zinc in mussel and sediment samples collected together from eight different geographical coastal areas of Chile were determined. The mussels studied were 'Chorito Maico', 'Almejas' and 'Navajuelas Chilenas' (Perumytilus purpuratus, Semelle solida and Tagellus dombeii, respectively). Sampling was carried out in July and September 1992 and January and April 1993 (winter, spring, summer and autumn seasons in Chile, respectively). The metal levels in these mussels varied among species; there were several sites where the metal concentrations in molluscs approached or exceeded the criteria levels for Cd, Cu and Zn in shellfish products: 1, 10 and 50 ppm ww respectively, which are regarded as safe levels for human consumption. The results of metal levels in sediments showed two areas clearly polluted with Cu. Strong relationships between Cu concentrations in the three molluscs and sediments were found; weak correlations were observed for Zn in S. solida.

Journal Article↗
PubMed1996

Increased frequency of HLA-DR3 and complotype SCO1 in Mexican mestizo children with amoebic abscess of the liver.

The increase of HLA-DR3 and complotype SCO1 previously found in Mexican mestizo adults with E. histolytica amoebic abscess of the liver, was also found in Mexican mestizo children of either sex with the same disease, when compared to the healthy control population (adults and/or children) of the same ethnic and socioeconomic background. This HLA and complotype pattern was not found in Mexican Mestizo patients with amoebic rectocolitis. No linkage disequilibrium was found between these and the other MHC determinants tested in this survey. Thus, HLA-DR3 and SCO1 may constitute primary, independent risk factors, not for any kind of amoebic tissue invasion (i.e. amoebic rectocolitis), but specifically for amoebic liver abscess, irrespective of age or sex. The possibility of linkage disequilibrium with other factors (i.e. the TNF family) within or close to the MHC that were not tested in this study, is discussed. Children with amoebic liver abscess revealed a significant increase in HLA-DR5, and the absence of HLA-DR6 when compared to adults with amoebic liver abscess, suggesting that at least in this ethnic group these class II HLA traits may contribute to some of the peculiarities of pediatric amoebic liver abscess as opposed to the adult version of this disease. HLA-DR3, SCO1, but also HLA-DR5 and HLA-DR6 have all been associated with certain forms of immune-dysfunction, and may thus contribute to some of the clinical and immunological features of this parasitic disease.

Adolescent↗
PubMed1995

Heterologous expression of Escherichia coli porin genes in Salmonella typhi Ty2: regulation by medium osmolarity, temperature and oxygen availability.

Electrophoretic analysis of outer membrane proteins showed that Salmonella typhi OmpC expression is not reciprocally regulated relative to OmpF as described for Escherichia coli and S. typhimurium. When bacteria were grown in minimal media, both OmpC and OmpF were repressed as the osmolarity increased. However, in Luria broth, expression of OmpC was slightly induced by osmolarity up to 0.3 osmM. Plasmids bearing E. coli ompC-lacZ or ompF-lacZ gene fusions were studied for their expression in S. typhi and E. coli. Under anaerobic growth conditions, expression of ompC-lacZ in S. typhi was maximal at 0.16 osmM, while in E. coli expression was maximal at 0.7 osmM. ompF-lacZ expression was similarly repressed by medium osmolarity and anaerobiosis in both species. In contrast, a drastic difference in the regulation of OmpF by temperature was observed; at 37 degrees C ompF-lacZ expression was repressed in E. coli, while in S. typhi it was induced.

Bacterial Outer Membrane Proteins↗
PubMed1995

Characterization of the regional distribution of selenium in Chile using selenium in hens' eggs as a monitor.

Regional distribution of selenium (Se) in Chile was investigated by using the concentration of Se in hens' eggs as a monitor. Forty-one locations along the entire length of the country were sampled. Average (+/- SD) egg-white Se content (mg/kg dry) was 0.79 +/- 0.41, range 0.22-2.23. Corresponding yolk Se values were, mean 0.81 +/- 0.43, (mg/kg dry) range 0.26-2.23. Locations grouped in five main areas, according to their geographic-climatic characteristics, showed significant differences regarding both egg-white Se and yolk Se. Analyzed dietary Se intake from two distinct areas reflected the trends observed in the Se content of egg fractions from such regions. These data support the utilization of the concentration of Se in hens' eggs as a useful monitor of dietary selenium consumed by selected populations.

Animals↗
PubMed1995

Factors associated with chronic renal failure in 121 patients with diffuse proliferative lupus nephritis: a case-control study.

Lupus nephritis remains an important problem in patients with systemic lupus erythematosus (SLE). Some patients with diffuse proliferative lupus nephritis (DPLN) develop chronic renal failure (CRF). A case-control study was designed to determine the variables associated with CRF in patients with DPLN. We studied 121 patients with biopsy-proven DPLN seen in our institution from 1970 to 1988. There were 34 patients who developed CRF, the remaining were their controls. Clinical charts were reviewed and a pathologist re-scored blindly both activity and chronicity indices. The mean of age at SLE onset was 24.1 +/- 7.9 years; the mean disease duration was 9.2 +/- 6.1 years for controls and 6.1 +/- 5 years for patients. The main variables associated with CRF were male sex. HR (hazard ratio): 12.6 (95% CI 1.6-98.2); activity index, HR 2.59 (1.07-6.3); severe infections, HR 2.9 (1.2-7.3): number of antihypertensive drugs, HR 2.5 (1.4-4.7); cellular crescents, HR 1.6 (1.2-2): and interstitial inflammation, HR 2.7 (1.5-5.1). A protective effect was observed with longer use of < or = 20 mg of prednisone, HR 0.53 (95% CI 0.34-08): azathioprine, HR 0.6 (0.4-0.8); and length of formal education. HR 0.3 (0.09-0.94). Our results indicate that maleness, activity index, extracapillary proliferation and interstitial inflammation, as well as hypertension and severe infections associate with CRF in patients with DPLN, and treatment and higher education, perhaps through better therapeutic compliance, may be protective.

Adolescent↗
PubMed1995

MR imaging and CT of central nervous system tuberculosis in the patient with AIDS.

CNS TB represents a disease that complicates AIDS with an increasing incidence in endemic areas as well as in developed countries in those patients who have some risk factors such as intravenous drug abuse. Although TB infection of the CNS in AIDS patients may follow a rapidly progressive course, the imaging findings otherwise are similar to those of the nonimmunosuppressed population. Meningeal enhancement, hydrocephalus, parenchymal granulomata, and infarcts are seen frequently and are often observed in combination with one another. Nevertheless, the differential diagnosis in AIDS patients must include other opportunistic infections and primary or metastatic lymphoma of the CNS. Spinal TB usually is seen in the form of epidural abscess secondary to tuberculous spondylitis, although it may be seen in isolation of spinal column involvement. The differential diagnosis includes spinal lymphoma or pyogenic abscess formation. Radiculomyelitis or isolated spinal cord tuberculomata are much less frequently observed and can be suspected on imaging only if there is concomitant evidence of the classic findings of intracranial TB.

AIDS-Related Opportunistic Infections↗
PubMed1994

Cadmium, lead, copper and mercury levels in fresh and canned bivalve mussels Tagelus dombeii (Navajuela) and Semelle sólida (Almeja) from the Chilean coast.

Samples of bivalve mussels Tagelus dombeii and Semelle sólida (Navajuelas and Almejas chilenas, respectively) caught at different sites along the coast of Chile were analysed for Cu, Cd, Hg and Pb content. The analyses were performed on samples of fresh and canned products, classified according to their length. Each Navajuela sample was divided into two subsamples. One was dissected and the visceral tissue, branchial tissue and gonads were removed, while the other sample consisted of the whole tissues. The heavy metal concentration of fresh mussel samples was compared with the same samples as canned products. The data show that for both species there are no significant differences in the metal concentration with the mollusc size in fresh samples and canned products. It has been shown that there is no contribution to the trace metal content (Cd, Pb and Hg) in canned Navajuelas and Almejas mussels as a consequence of the industrial process. A clear and significant reduction in the Cd and Cu content was observed in Navajuelas without visceral tissue and Almejas without mantle tissue for both the fresh and canned products. This is consistent and is corroborated with the high metal concentrations found in the visceral and mantle tissue.

Animals↗