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M Arango

Publications and source records attributed to M Arango.

14 recordsLinked to original sources
PubMed1997

Distribution of capsular types and antimicrobial susceptibility of invasive isolates of Streptococcus pneumoniae in Colombian children. Pneumococcal Study Group in Colombia.

Streptococcus pneumoniae is the leading bacterial cause of childhood pneumonia in the developing world. This study describes the type distribution and antimicrobial susceptibility of invasive pneumococcal isolates from Colombian children and is part of the Sistema Regional de Vacunas (SIREVA), a PAHO regional initiative designed to determine the ideal serotype composition of a protein polysaccharide pneumococcal conjugate vaccine for use in children less than 5 years old in Latin America. In Colombia, during the study period, centres in Bogota, Medellin, and Cali collected 324 S. pneumoniae isolates from invasive diseases, 238 (73.5%) from children under the age of 2. Pneumonia was the clinical diagnosis in 41.3% cases, meningitis in 41%, and sepsis in 11.2%. The seven most frequent types included 14(21.9%), 5(10.5%), 23F(9.6%), 1(9%), 6B(9%), 19F(7.1%), and 6A(6.2%). The frequency of diminished susceptibility to penicillin (DSP) was 12%, with 8.9% of isolates showing intermediate level resistance and 3.1% showing high level resistance. Among DSP isolates, 23% were also resistant to cefotaxime, 33.3% to erythromycin, 48.7% to chloramphenicol, and 74.3% to trimethoprim/sulfamethoxazole. Multiple resistance was detected in 59% of the isolates that have DSP. Penicillin resistance was associated with types 23F (53.8%) and 14 (25.6%). These data provides information on capsular types prevalent in Colombia that will not only allow the formulation of an ideal vaccine for the region but also reinforce the need for ongoing regional surveillance.

Anti-Bacterial Agents↗
PubMed1997

[The value of immunological assays in the diagnosis of meningeal histoplasmosis].

INTRODUCTION: Between 1985 and 1995, 3,860 cerebrospinal fluid (CSF) samples from patients with mycotic meningitis were analyzed. METHODS: Direct examination, cultures, complement fixation (CF) and immunodiffusion (ID) with Histoplasma capsulatum were carried out. RESULTS: Seventy four samples from 31 patients (three of them with AIDS) were reactive at the immunological assays. Cultures were positive in five patients. In 26 patients the clinical diagnosis together with positive CSF assays gave indirect evidence of meningeal histoplasmosis. ID and CF reactivity were 93.5% and 100% respectively. For 23 patients who had simultaneous examination of blood and CSF the double positivity was 78.2%. CONCLUSIONS: Because of the direct isolation of Histoplasma capsulatum is a difficult one, the diagnosis of subacute or chronic meningeal histoplasmosis may be confirmed by indirect immunological assays.

Adolescent↗
PubMed1996

Disseminated histoplasmosis in children: the role of itraconazole therapy.

OBJECTIVES: To describe the clinical characteristics and laboratory diagnosis of seven children with disseminated histoplasmosis and evaluate the effectiveness of itraconazole therapy in this severe form of the mycosis as well as to determine the long term results of such treatment. METHODS: The diagnosis of histoplasmosis was based on the direct observation of Histoplasma capsulatum var. capsulatum and/or on the isolation of the fungus from pathologic materials; the results of the serologic tests were taken into consideration. Chest roentgenograms also contributed to the diagnosis. PATIENTS: The patients were seven rural children, five girls and two boys, ages 1 to 14 years (mean, 4.6), with a confirmed diagnosis of disseminated histoplasmosis and who had no underlying disease other than malnourishment. RESULTS: The seven children experienced a subacute febrile syndrome for 4 months accompanied by anorexia, weight loss and signs of reticuloendothelial involvement such as lymph node hypertrophy, hepatomegaly and/or splenomegaly. The lung revealed roentgenographic alterations consisting mainly of nodular infiltrates. All patients received itraconazole orally in a mean dosage of 7.2 mg/kg/day, for variable periods (3 to 12 months), depending on the individual response and the toxic effects of the medication. One of the patients who was improving after 1 month of treatment was taken from the hospital by his guardian against medical advice and died shortly afterward. The remaining six patients responded to the treatment with marked clinical improvement and showed negative cultures and decreases in anti-H. capsulatum antibody titers after 3 months of treatment. Only one patient, the youngest and most severely affected child, exhibited hepatotoxicity, which subsided when itraconazole was discontinued. Extended follow-up studies revealed no relapses. CONCLUSION: The results of this study indicate that itraconazole is effective for treatment of disseminated childhood histoplasmosis. More studies should be performed to determine the most appropriate dosage and the optimal duration of itraconazole treatment in children.

Adolescent↗
PubMed1988

Morphological differences between Venezuelan and African microfilariae of Onchocerca volvulus.

Comparative morphological and biometric characteristics of microfilariae of Onchocerca gutturosa and O. volvulus from different geographical areas (Upper Orinoco, Venezuela; Togo; Liberia) were assessed. "Stepwise" discriminant analysis and Mahalanobis estimators were applied to measure distance between populations. The results indicate a strong similarity between the two strains from the Upper Orinoco (Venezuela) and the Togo strain, as well as a clear separation between these strains and that of O. gutturosa. The Liberian strain was easily distinguishable from microfilariae from Togo and Venezuela. Discriminant analysis showed the Liberian deme to be as different from the Venezuelan and Togo demes as these demes were from microfilariae of the reference species, O. gutturosa. Although it is necessary to confirm these data using formalin-fixed specimens obtained from the skin, the present findings suggest the existence of geographically-different strains of O. volvulus in America and Africa.

Animals↗
PubMed1988

Treatment of chromoblastomycosis with itraconazole.

The results of long-term itraconazole therapy in 10 patients with active chromoblastomycosis due to F. pedrosoi were reported. Therapy consisted of 100 or 200 mg/day of itraconazole, the length of therapy depending on the patient's response (12 to 24 months). This new triazole proved effective in reducing the number, size, and severity of the lesions in nine of the patients. Those patients with minor involvement profited more from therapy and were cured; patients with moderate involvement achieved either minor or major improvement. In most cases, signs and symptoms began to improve after 6 months of therapy. Mycological tests (in which tissue samples were treated with potassium hydroxide and cultured) became negative in six patients, but the fungus was eradicated in only three patients. Itraconazole produced no side effects. In spite of the need for long-term therapy, this new azole derivative effectively controls the disease.

Antifungal Agents↗
PubMed1987

Reduction of malaria prevalence after introduction of Romanomermis culicivorax (Mermithidae: Nematoda) in larval Anopheles habitats in Colombia.

The worldwide resurgence of malaria has become a major public health problem. New methods of controlling the vectors of the disease are required, and we therefore studied the biological control of Anopheles albimanus by Romanomermis culicivorax in Colombia. The investigation was carried out in El Valle and Nuquí, two towns on the northern Pacific coast of the country. All of the mosquito larval habitats surrounding El Valle were seeded with the eggs and adults of R. culicivorax. The nematode established itself in the new habitat and recycled over 27 months. The larval population of A. albimanus, the only malarial vector detected in the two towns, decreased in El Valle. In contrast, no change in the larval populations of the vector was detected in ponds located near Nuquí, the untreated control town. A rapid and progressive decrease of the prevalence of malaria among schoolchildren in El Valle was observed during the 2-year evaluation period.

Animals↗
PubMed1985

Characteristics of the conidia produced by the mycelial form of Paracoccidioides brasiliensis.

The sporulation capacities of the mycelial form of Paracoccidioides brasiliensis were determined. Five different culture media were used and four human isolates studied. Conidia were produced in three agar media, namely water-agar, glucose-salts and yeast-extract. Corn meal and Sabouraud dextrose agars failed to induce sporulation. Various types of spores were characterized with peculiar bulging arthroconidia and single-celled, pear-shaped conidia predominating. The size of these conidia varied from 3.6 to 4.6 micron in length. It is concluded that the mycelial form of P. brasiliensis produces characteristic spores if the proper culture media are employed.

Mitosporic Fungi↗
PubMed1984

Onchocerciasis in Venezuela: prevalence of microfilaraemia in Amerindians and morphological characteristics of the microfilariae from the Upper Orinoco Focus.

Data are presented on microfilaraemia in 191 Yanomami Amerindians from two areas of Venezuela's Upper Orinoco Basin, where an endemic focus of onchocerciasis has been recently detected. Onchocerca microfilariae were found in the blood of 12.6% of the persons examined. In the village with the higher number of examined individuals (N = 162), the prevalence of microfilaraemia in the age groups covaried with the prevalence of microfilariae in the skin and with the parasite load (mf/mg of skin). A positive correlation was found between age and these three variables. The prevalence of Onchocerca microfilaraemia in the Upper Orinoco focus is high, and may be related to the ability of the strain to invade the blood stream. Morphobiometric characteristics of the Onchocerca microfilariae isolated from human blood are similar to those of O. volvulus fixed in formalin from skin and from the uterus of female O. volvulus worms. All have a very short cephalic space. Comparisons with the entity from the Upper Caura river designated as Microfilaria bolivarensis were also made. It was concluded that there are no valid biometric differences in thick blood smears between microfilaria bolivarensis and microfilaria of O. volvulus from the Upper Orinoco deme. A more striking difference may be in the concentration of microfilariae observed in the blood, which in one case of mf. bolivarensis was more than forty times the highest number recorded for microfilaria O. volvulus in Parima.

Adolescent↗
PubMed1983

Acid phosphatase patterns in microfilariae of Onchocerca volvulus s.l. from the Upper Orinoco Basin, Venezuela.

The patterns of acid phosphatase in strains of Onchocerca volvulus s.l. which parasitize an Amerindian population (Yanomami) in Venezuela's Upper Orinoco Basin were examined by using the naphthol AS-TR phosphate method. The study sample consisted of 40 Yanomami inhabiting a savannah area at 950 m above sea level and 21 Yanomami residents of a tropical rainforest area at an altitude of 250 m. Stained intrauterine microfilariae, still within the egg case, exhibited a diffuse distribution of the enzyme in the early stages of embryonic development and a negative reaction at a more developed stage. Four of the five enzyme staining patterns described by Omar (1978) were found in the 3157 microfilariae examined from skin snips. Their distribution was: Type I--17.2%, Type III--0.5%, Type IV--75.6% and Type V--6.6%. No examples of Type II were observed. The results indicate that acid phosphatase patterns of the Upper Orinoco Onchocerca strain most resemble those of strains from Guatemala and Yemen, and are different from the African strains found in Upper Volta and Liberia. The relative frequency of acid phosphatase patterns was modified by cryopreservation of microfilariae.

Acid Phosphatase↗
PubMed1982

T-cell dysfunction and hyperimmunoglobulinemia E in paracoccidioidomycosis.

Various aspects of T and B cell mediated immunity were investigated in 20 well documented cases of active (10) or inactive (10) paracoccidioidomycosis (Pcm), as well as in 8 healthy individuals living in the endemic area of the disease. The results confirm previous reports that active Pcm produces diverse grades of depression of T cell mediated immunity. Such T cell dysfunction is not associated with a reduction in the number of peripheral E rosette-forming cells, and the immunodepression is reversed by chemotherapy. Sera from Pcm (active or inactive) patients have significantly increased levels of total IgE, but the actual proportion of IgE antibodies against P. brasiliensis was very low (0.4-0.6%). The highest levels of total IgE were found in active patients with disease-related immune depression, suggesting that T cell dysfunction might contribute to the excessive IgE production.

Adolescent↗
PubMed1980

Demonstration and quantification oomycosis.

Using a radioimmunoassay technique, we have determined the total IgE concentration and specific IgE antibody level against Paracoccidioides brasiliensis in the sera of patients with mycologically confirmed active paracoccidioidcosis. Patients with aspergilloma, or individuals with antibodies against Cadida albicans, and sera of apparently healthy individuals from the endemic area were also examined. The level of total IgE was significantly elevated in 9 out of 10 cases of paracoccidioidomycosis. The mean level of specific IgE against P. brasiliensis was significantly higher in the serum of the patients in comparison with control individuals. The percentage of specific IgE relative to the total varied from 0.38 to 2.28%. The differences between IgE levels in pare other mycoses were statistically significant. Our results suggest a possible involvement of specific IgE antibodies against P. brasiliensis in the immune response of patients with paracoccidioidomycosis. The hyperimmunoglobulinemia E may be related to the T-cell defect that characterizes the severe forms of the disease.

Adolescent↗
PubMed1976

Determination of the growth curves of the mycelial and yeast forms of Paracoccidiodes brasiliensis.

The growth curves of 2 different strains of P. brasiliensis were determined. Cultures were made in a dialyzed trypticase soy broth and the growth assesed at selected intervals by means of viable cell counts. In the yeast form, both strains exhibited un uniform pattern of growth; the mycelial forms were also similar although one of the strains survived for a longer period of time. When the 2 yeast curves were compared with the mycelial ones, large differences were noticed. Thus, the mean survival time for the yeasts was 13.5 days while it was 50.25 days for the mycelia. During the exponential phase, the mean rate of growth was accelerated for the yeasts (0.110) in comparison with the one exhibited by the mycelia (0.0265). Irrespective of the form of growth and for both strains, death occurred abruptly, a few hours after a period when colony counts were high, indicating that the fugus was viable at the preceeding interval.

Fungi↗
PubMed1976

The isolation of Botryodiplodia theobromae from a nail lesion.

Botryodiplodia theobromae not known to produce onychomycosis was repeatedly recovered from a healthy woman with evident lesions in a toe nail. Mycelial fragments were observed in the scales and the fungus was isolated in cycloheximide-free culture media. The report indicates that many fungi, hitherto considered non-pathogens, may still be able to colonize a vaiety of human tissues.

Adult↗