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Search Results: 1 - 10 of 76573 matches for " Paz Maria Salazar-Schettino "
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Evaluación de la función y sincronía de la contracción ventricular en pacientes con enfermedad de Chagas en estadio de latencia
Nivardo Sobrino, Ayax;Jiménez-ángeles, Luis;Bialostozky, David;Vázquez, Clara;Martínez, Irma;Salazar-Schettino, Paz Maria;Bucio-Torres, Martha;Ruiz-Hernández, Adela;Cabrera-Bravo, Margarita;
Archivos de cardiología de México , 2009,
Abstract: objective: to compare the left ventricular function and the ventricular synchrony in patients with chagas disease in latency stage respect to a control group. methods: we analyze a prospective, comparative, transversal and non randomized study of the left ventricular function (lvf) and the ventricular contraction synchronicity (vcs) in 36 subjects with positive serology for chagas disease (18 males and 18 females), with mean of 15 ± 5 years old. the findings were compared with respect to 23 control volunteers (11 males and 12 females) with mean of 28 ± 5 years old. lvf and vcs were evaluated using equilibrium radionuclide angiography images (erna). the comparison of both chagas and control populations was carried out by t student test for independent samples, considering a statistically significant value of p < 0.05. results: the parameters of the ventricular function and the ventricular synchronicity in subjects with positive serology for chagas disease were not statistically different with respect to the parameters of the control group. however, although they have a homogeneous contraction, the mean time of contraction for the right and the left ventricle is statistically smaller with respect to the control group. conclusions: in clinically incipient stages of chagas disease we do not found abnormalities in the ventricular function and the ventricular synchronicity. it's necessary to consider the follow up of the studied populations using indices for the identification of abnormalities of the autonomic nervous system.
Phylogeographic Pattern and Extensive Mitochondrial DNA Divergence Disclose a Species Complex within the Chagas Disease Vector Triatoma dimidiata
Fernando A. Monteiro, Tatiana Peretolchina, Cristiano Lazoski, Kecia Harris, Ellen M. Dotson, Fernando Abad-Franch, Elsa Tamayo, Pamela M. Pennington, Carlota Monroy, Celia Cordon-Rosales, Paz Maria Salazar-Schettino, Andrés Gómez-Palacio, Mario J. Grijalva, Charles B. Beard, Paula L. Marcet
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0070974
Abstract: Background Triatoma dimidiata is among the main vectors of Chagas disease in Latin America. However, and despite important advances, there is no consensus about the taxonomic status of phenotypically divergent T. dimidiata populations, which in most recent papers are regarded as subspecies. Methodology and Findings A total of 126 cyt b sequences (621 bp long) were produced for specimens from across the species range. Forty-seven selected specimens representing the main cyt b clades observed (after a preliminary phylogenetic analysis) were also sequenced for an ND4 fragment (554 bp long) and concatenated with their respective cyt b sequences to produce a combined data set totalling 1175 bp/individual. Bayesian and Maximum-Likelihood phylogenetic analyses of both data sets (cyt b, and cyt b+ND4) disclosed four strongly divergent (all pairwise Kimura 2-parameter distances >0.08), monophyletic groups: Group I occurs from Southern Mexico through Central America into Colombia, with Ecuadorian specimens resembling Nicaraguan material; Group II includes samples from Western-Southwestern Mexico; Group III comprises specimens from the Yucatán peninsula; and Group IV consists of sylvatic samples from Belize. The closely-related, yet formally recognized species T. hegneri from the island of Cozumel falls within the divergence range of the T. dimidiata populations studied. Conclusions We propose that Groups I–IV, as well as T. hegneri, should be regarded as separate species. In the Petén of Guatemala, representatives of Groups I, II, and III occur in sympatry; the absence of haplotypes with intermediate genetic distances, as shown by multimodal mismatch distribution plots, clearly indicates that reproductive barriers actively promote within-group cohesion. Some sylvatic specimens from Belize belong to a different species – likely the basal lineage of the T. dimidiata complex, originated ~8.25 Mya. The evidence presented here strongly supports the proposition that T. dimidiata is a complex of five cryptic species (Groups I–IV plus T. hegneri) that play different roles as vectors of Chagas disease in the region.
First Case of Natural Infection in Pigs: Review of Trypanosoma cruzi Reservoirs in Mexico
Salazar-Schettino Paz María,Bucio Martha Irene,Cabrera Margarita,Bautista Jacobo
Memórias do Instituto Oswaldo Cruz , 1997,
Abstract: An epidemiological research project was performed in the State of Morelos including collection of samples for blood smears and culture, serological tests, and xenodiagnoses from a total of 76 domestic and peridomestic mammals. Two strains of Trypanosoma cruzi were isolated by haemocultures; one from a pig (Sus scrofa), the first case of natural infection reported in Mexico, and the other from a dog (Canis familiaris). This study summarizes current information in Mexico concerning confirmed reservoirs of T. cruzi
Enteroparasitosis en poblaciones indígenas y mestizas de la Sierra de Nayarit, México
Parasitología latinoamericana , 2003, DOI: 10.4067/S0717-77122003000100005
Abstract: we compared the prevalences of enteroparasitoses from 420 individuals, 306 of them were indigenous and 114 were mestizo persons, without gender differentiation, and of all ages from the nayarit mountain range. six field trips were made to the region during one year to collect the stool samples, some individuals provided only one sample and other even five. stool samples were suspended 1:5 with 10% formalin for their transportation to mexico city, where they were processed by direct parasitoscopic analysis with lugol solution we found entamoeba histolytica, 59.8%; giardia lamblia, 22.2%; enterobius vermicularis, 22.2%; hymenolepis nana, 15.4%; 2 cases of taeniosis (0.7%), 21 of ascariosis (6.9%), 2 of strongyloidosis (0.7%) and 7 of trichuriosis (2.3%) among the huichol population. for the mestizo population, we found 43.9% of entamoebosis, 14.0% giardiosis, 9.6% hymenolepiosis, 5 cases of ascariosis, 2 of taeniosis, 1 of strongyloidosis and 1 of enterobiosis. chi-square test revealed statistically significant differences between the two populations for some of the calculated prevalences
Influence of temperature and humidity on the biology of Triatoma mexicana (Hemiptera: Reduviidae: Triatominae) under laboratory conditions
Martínez-Ibarra, José Alejandro;Salazar-Schettino, Paz María;Solorio-Cibrián, Miriam;Cabrera Bravo, Margarita;Novelo-López, Mónica;Vences, Mauro Omar;Montes-Ochoa, Jazmín Yesenia;Nogueda-Torres, Benjamín;
Memórias do Instituto Oswaldo Cruz , 2008, DOI: 10.1590/S0074-02762008000700015
Abstract: several biological parameters related to the triatoma mexicana life-cycle were evaluated in this study. three cohorts were maintained under different combinations of temperature and relative humidity (rh): 25oc/50% rh; 25oc/75% rh; and 30oc/75% rh. observed hatching rates varied from 49-57.5% whereas the average time of hatching varied from 19.5-22.7 days. in the three cohorts studied, the mean time-lapse between presentation of the blood meal and the beginning of feeding was less than 5 min in all instars; the mean feeding time was longer than 10 min in all the instars; the post-feed defecation delay was over 10 min in all the instars. less than 50% of nymphs in each cohort completed the cycle and the average time from 1st instar nymph to adult was more than 255 days for the three cohorts. the number of blood meals before molt at each nymphal instar varied from 1-9. our results appear to indicate a lack of influence of temperature and rh on the biological parameters of t. mexicana that were studied, which could reflect the adaptation capacity of this species. we also conclude that t. mexicana can not be considered an effective transmitter of trypanosoma cruzi to human populations in areas where this species is currently present.
Occurrence of hybrids and laboratory evidence of fertility among three species of the Phyllosoma complex (Hemiptera: Reduviidae) in Mexico
Martínez-Ibarra, José Alejandro;Salazar-Schettino, Paz María;Nogueda-Torres, Benjamín;Vences, Mauro Omar;Tapia-González, José María;Espinoza-Gutiérrez, Bertha;
Memórias do Instituto Oswaldo Cruz , 2009, DOI: 10.1590/S0074-02762009000800009
Abstract: in seven studied communities of western mexico, triatomine specimens were sympatrically collected, some with atypical morphological characteristics in contrast to pure specimens, which were presumed to be hybrids. more than 200 specimens of meccus pallidipennis and meccus longipennis with brown-yellow markings on dorsal connexival segments were collected in ahuacapán and quitupan. in la mesa, more than 60 specimens similar to meccus picturatus in most morphological characteristics (including size) were collected, although they presented a largely yellowish corium like m. pallidipennis. interfertility was proven between all of the studied wild hybrid specimens, as well as between all the experimental laboratory hybrids. two different phenotypes (m. picturatus and m. longipennis) were obtained from crosses between m. picturatus x m. picturatus and m. longipennis x m. longipennis from the three studied localities in state of nayarit as from la mesita. results support the hypothesis that the subspecific ranking of those triatomines may, therefore, be more appropriate because reproductive isolation has not been developed and complete interbreeding was recorded.
Phylogeography and Genetic Variation of Triatoma dimidiata, the Main Chagas Disease Vector in Central America, and Its Position within the Genus Triatoma
María Dolores Bargues ,Debora R. Klisiowicz,Fernando Gonzalez-Candelas,Janine M. Ramsey,Carlota Monroy,Carlos Ponce,Paz María Salazar-Schettino,Francisco Panzera,Fernando Abad-Franch,Octavio E. Sousa,Christopher J. Schofield,Jean Pierre Dujardin,Felipe Guhl,Santiago Mas-Coma
PLOS Neglected Tropical Diseases , 2008, DOI: 10.1371/journal.pntd.0000233
Abstract: Background Among Chagas disease triatomine vectors, the largest genus, Triatoma, includes species of high public health interest. Triatoma dimidiata, the main vector throughout Central America and up to Ecuador, presents extensive phenotypic, genotypic, and behavioral diversity in sylvatic, peridomestic and domestic habitats, and non-domiciliated populations acting as reinfestation sources. DNA sequence analyses, phylogenetic reconstruction methods, and genetic variation approaches are combined to investigate the haplotype profiling, genetic polymorphism, phylogeography, and evolutionary trends of T. dimidiata and its closest relatives within Triatoma. This is the largest interpopulational analysis performed on a triatomine species so far. Methodology and Findings Triatomines from Mexico, Guatemala, Honduras, Nicaragua, Panama, Cuba, Colombia, Ecuador, and Brazil were used. Triatoma dimidiata populations follow different evolutionary divergences in which geographical isolation appears to have had an important influence. A southern Mexican–northern Guatemalan ancestral form gave rise to two main clades. One clade remained confined to the Yucatan peninsula and northern parts of Chiapas State, Guatemala, and Honduras, with extant descendants deserving specific status. Within the second clade, extant subspecies diversity was shaped by adaptive radiation derived from Guatemalan ancestral populations. Central American populations correspond to subspecies T. d. dimidiata. A southern spread into Panama and Colombia gave the T. d. capitata forms, and a northwestern spread rising from Guatemala into Mexico gave the T. d. maculipennis forms. Triatoma hegneri appears as a subspecific insular form. Conclusions The comparison with very numerous Triatoma species allows us to reach highly supported conclusions not only about T. dimidiata, but also on different, important Triatoma species groupings and their evolution. The very large intraspecific genetic variability found in T. dimidiata sensu lato has never been detected in a triatomine species before. The distinction between the five different taxa furnishes a new frame for future analyses of the different vector transmission capacities and epidemiological characteristics of Chagas disease. Results indicate that T. dimidiata will offer problems for control, although dwelling insecticide spraying might be successful against introduced populations in Ecuador.
Analysis of Variability of Clones and Subclones of Trypanosoma cruzi Derived from Mexican Strains by the Behavior in Mice and Culture Cells
Marco Antonio Becerril Flores,Salazar Schettino Paz Maria,Ramirez Zamudio Lina
Research Journal of Medical Sciences , 2012,
Abstract: To better understand the biological heterogeneity of behavior of Trypanosoma cruzi strains isolated from Mexico, 6 strains of T. cruzi were cloned by the Miles method (drops of suspension with parasites were diluted in phosphate-buffered saline solution and inoculated to mice).Virulence and infectivity of 10 or 11 clones derived from each strain were determined in female Balb/c mice and Vero culture cells, respectively. Variability of clones was determined by Tukey F statistic test. Only 1 strain, T5, showed interclonal variability and its clones were subcloned by the same method; they showed similar behavior as their parental clones. Clones increased the virulence or had the same behavior after maintaining them for 1 year in mice. Seven clones were eliminated and the virulence of the 4 remaining clones was attenuated when they were maintained in LIT axenic culture for 1 year. The study showed that the strains of T. cruzi in Mexico are either monoclonal or polyclonal and the clones could be eliminated or selected from the environment along time; therefore it is possible to observe that the behavior of T. cruzi strains can change when they are maintained in laboratory for several years.
Tres especies de triatominos y su importancia como vectores de Trypanosoma Cruzi en México
Salazar Schettino,Paz M.; de Haro Arteaga,Irene; Cabrera Bravo,Margarita;
Medicina (Buenos Aires) , 2005,
Abstract: observations made in the field and in the laboratory on three vectors of trypanosoma cruzi: triatoma barberi, t. pallidipennis and t. dimidiata are here presented. results are compared in relation with their ecotopes, vectorial capacity, biological characteristic, entomological indexes and capture places. in relation with their ecotopos t. barberi has preference for the interior of the human home, in walls, directly in contact with beds; t. pallidipennis, when it is inside the houses, prefers floors and among clothes, although their main ecotope is wild; t. dimidiata has localization in floors, specially under the beds, in the angle between wall and floor; t. barberi and t. dimidiata are attracted by the light. the cycles of life were of 523, 171 and 510 days, respectively for triatoma barberi, t. pallidipennis and t. dimidiata. the vectorial capacity was determined according to the time taken in defecating during or after its sucking blood: t. barberi defecates during its feeding, while t. pallidipennis and t. dimidiata make it from 10 to 20 and of 20 to 30 minutes after starting the process, respectively. the indexes of natural infection were of 56.6 for t.barberi, 29 for t.pallidipennis and 15.6 for t. dimidiata, the metacyclogenics indexes that indicate percentages of metacyclics trypomastigotes in later intestine of vectors was in t. barberi 76.6, t. pallidipennis 15 and t. dimidiata 26, with what it can be concluded that the first species is the best transmitter of t. cruzi in mexico.
Cuticular hydrocarbons of Chagas disease vectors in Mexico
Juárez, M Patricia;Carlson, David A;Salazar Schettino, Paz María;Mijailovsky, Sergio;Rojas, Gloria;
Memórias do Instituto Oswaldo Cruz , 2002, DOI: 10.1590/S0074-02762002000600012
Abstract: capillary gas-liquid chromatography was used to analyse the cuticular hydrocarbons of three triatomine species, triatoma dimidiata, t. barberi and dipetalogaster maxima, domestic vectors of chagas disease in mexico. mixtures of saturated hydrocarbons of straight and methyl-branched chains were characteristic of the three species, but quantitatively different. major methylbranched components mostly corresponded to different saturated isomers of monomethyl, dimethyl and trimethyl branched hydrocarbons ranging from 29 to 39 carbon backbones. sex-dependant, quantitative differences in certain hydrocarbons were apparent in t. dimidiata.
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