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M Contreras

Publications and source records attributed to M Contreras.

At least 271 records · Page 15Linked to original sources
PubMedDate not supplied

Seroepidemiology of human toxoplasmosis in Chile.

A series of already published and unpublished seroepidemiological surveys for toxoplasmosis, carried out in Chile in 1982-1994, is reviewed, expanded and analyzed. The surveys included 76,317 apparently healthy individuals of different ages (0.57% of the country's total population), from 309 urban and rural-periurban localities. Urban groups were integrated by blood donors, delivering mothers and middle grade schoolchildren, while rural-periurban individuals corresponded to unselected family groups. Blood samples were collected in filter paper. The presence of antibodies to Toxoplasma gondii was determined by the indirect hemagglutination test (IHAT), titers > or = 16 were considered positive. The test resulted positive in 28,124 (36.9%) of the surveyed people. Two hundred and six (0.3%) individuals presented IHAT titers > or = 1000, probably corresponding to acute or reactivated infections. A progressive increase of positive IHAT from northern to southern regions of the country was noted, phenomenon probably related to geographical conditions and to a higher production and consumption of different types of meat in the latter regions. It is postulated that ingestion of T gondii cysts by humans is epidemiologically as important as ingestion of oocysts. The result presented stress the epidemiological importance of toxoplasmosis in humans, and warn about eventual implications in immunocompromised patients and in transplacental transmission, organ transplants and transfusions.

Adult↗
PubMedDate not supplied

Hospital control and multidrug-resistant pulmonary tuberculosis in female patients, Lima, Peru.

We examined the prevalence of tuberculosis (TB), rate of multidrug-resistant (MDR) TB, and characteristics of TB on a female general medicine ward in Peru. Of 250 patients, 40 (16%) were positive by sputum culture and 27 (11%) by smear, and 8 (3%) had MDRTB. Thirteen (33%) of 40 culture-positive patients had not been suspected of having TB on admission. Six (46%) of 13 patients whose TB was unsuspected on admission had MDRTB, compared with 2 (7%) of 27 suspected cases (p = 0.009). Five (63%) of 8 MDRTB patients were smear positive and therefore highly infective. In developing countries, hospital control, a simple method of reducing the spread of MDRTB, is neglected.

Adolescent↗
PubMedDate not supplied

Determination of imidacloprid and benzimidazole residues in fruits and vegetables by liquid chromatography-mass spectrometry after ethyl acetate multiresidue extraction.

A simple and sensitive method based on liquid chromatography-atmospheric pressure ionization-mass spectrometry is described for the determination of 4 benzimidazole pesticides (carbendazim, thiabendazole, benomyl, and thiophanate-methyl) and imidacloprid in vegetables and fruits. Food samples were typically extracted with ethyl acetate to draw the analytes into the organic phase. No cleanup step was necessary before injection into the liquid chromatographic (LC) system with electrospray mass spectrometric detection. The analytes were separated on a reversed-phase C8LC column. Limits of detection for the compounds were in the microg/L range. Results are reported for validation studies with fortified pear and tomato samples and for residues of the target compounds found in the pesticide residue monitoring program during 1998.

Acetates↗
PubMedDate not supplied

[Electrocardiographic alterations in persons with a positive serology for toxoplasmosis].

To each of 11,161 randomly taken people from urban and peri-urban localities of the first seven regions of Chile (geographic area of distribution of Chagas' disease in the country), with negative serology for Chagas' disease, an indirect hemagglutination test (IHAT) for toxoplasmosis and an EKG were practiced. The IHAT for toxoplasmosis resulted positive in 3,519 individuals (31.5%). The EKG showed alterations in 10.9% of the IHAT positive individuals and in 7.9% of the IHAT negative ones. This difference between the proportion of altered EKG in IHAT positive people and altered EKG in those with negative IHAT is statistically significative with p < 0.001. These results suggest the convenience of considering toxoplasmosis as a cause of chronic myocardiopathy in epidemiological studies on Chagas' disease, since not discard the presence of Toxoplasma gondii infection should overvaluete the magnitude of the impact of Trypanosoma cruzi in the genesis of such a myocardiopathy.

Adolescent↗
PubMedDate not supplied

[Nonspecific aorto-arteritis. Anatomo-pathological study of 18 cases].

The present study comprises a pathological review of 18 necropsy cases with nonspecific aorto-arteritis (Takayasu's disease), autopsied at the Instituto Nacional de Cardiología of Mexico up to 1976. There were 11 females and 7 males with an average age at the time of death of 21.5 years. A comparison according to the distribution and extention of arterial lesions disclosed that our cases are often less classical than those described from Japan. The principal arterial changes were stenosis, occlusion, dilatation and aneurysm formation in the aorta, its branches and main pulmonary artery. More often than not the aorta was extensively involved. The aortic arch syndrome and renovascular hypertension were almost equally present in this serie and an unusual high incidence of coronary artery involvement (33%) leading to myocardial infarction (50%) also was observed. The significance of the intrapulmonary vascular changes in Takayasu's arteritis is discussed.

Adolescent↗
PubMedDate not supplied

[Hygroma colli].

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Female↗
PubMedDate not supplied

[Takayasu disease].

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Aortic Arch Syndromes↗