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The phytoplankton of Guanabara Bay, Brazil: I. historical account of its biodiversity
Villac, Maria Célia;Tenenbaum, Denise Rivera;
Biota Neotropica , 2010, DOI: 10.1590/S1676-06032010000200030
Abstract: this is a historical account of the biodiversity of phytoplankton in guanabara bay, brazil. it is based on 57 publications that refer to sampling carried out between 1913 and 2004. the publications included are those with direct microscopic identification. although 80% of the studies focus on ecological issues that tend to mention only the most abundant species, 24 publications provide comprehensive check-lists at the species level, especially of taxa > 20 μm. the inventory of species includes, to date, 308 taxa among 199 diatoms, 90 dinoflagellates, 9 cyanobacteria, 5 euglenophyceans, 1 chlorophycean, 1 prasinophycean, 1 silicoflagellate, and 2 ebriids. the most conspicuous species were the dinoflagellate scrippsiella trochoidea and diatoms from the skeletonema costatum complex. the first was the theme of the very first publication in the area (faria 1914) that reported on its bloom associated with the mass mortality of fish due to oxygen depletion; it is still often found in high abundances (106 cell.l-1) in more protected areas. the second was long considered in the literature as a cosmopolitan and opportunistic species, until the recent discovery of cryptic species within the genus; taxonomic re-evaluation of local populations is, therefore, needed. besides these two species, only other 25 species stood out in terms of frequency of occurrence and widespread distribution in the bay, some known to be implicated in harmful blooms elsewhere. the biodiversity of dinoflagellates, especially within the gymnodiniales, and that of other unidentified flagellates (haptophyceae, cryptophyceae, prasinophyceae, raphidophyceae) is largely underestimated because of the use of fixatives that distort/destroy diagnostic characters. from the initial inventory of 124 taxa published in 1917 and the subsequent additions in species numbers, one can have a false perception that the phytoplankton biodiversity has increased throughout the years, despite the overall increase in eutrophicat
Criptosporidiosis intestinal en ni os con HIV/SIDA Intestinal cryptosporidiosis in HIV infected children
Graciela Barboni,Marcela Candi,María Inés Villacé,Araceli Leonardelli
Medicina (Buenos Aires) , 2008,
Abstract: El Cryptosporidium parvum, protozoo parásito intracelular, infecta el epitelio gastrointestinal produciendo diarrea autolimitada en individuos inmunocompetentes pero potencialmente grave en pacientes inmunocomprometidos, especialmente en aquellos con Sida. En este trabajo se evaluó, durante un lap-so de 6 a os, la incidencia de infección intestinal por C. parvum en una población pediátrica con HIV/Sida analizando las características clínicas e inmunológicas de la coinfección. Todos los pacientes iniciaron o continuaron el tratamiento antirretroviral de alta eficacia HAART durante el período de estudio, mientras que la infección intestinal fue tratada con azitromicina. La incidencia de criptosporidiosis fue de 13.7%. 33 de los 240 ni os en seguimiento presentaron diarrea crónica de más de 14 días de evolución o recurrente, sin complicaciones hidroelectrolíticas. Los pacientes evaluados presentaron niveles porcentuales variables de células T CD4+ en sangre periférica, y la presencia del parásito no estuvo en relación con el compromiso inmunitario. Al momento del cuadro entérico 31 de los 33 pacientes tuvieron niveles plasmáticos de carga viral que superaban el límite de detección. Se observó eosinofilia leve o moderada en el 23% de los pacientes y la coinfección con otros parásitos fue detectada en 11 ni os. No se obtuvieron diferencias significativas al relacionar el número de episodios intestinales con los estadios clínico-inmunológicos de los pacientes. La correcta implementación del HAART con la subsecuente restauración de la función inmune se relacionaría con la ausencia de cuadros diarreicos agudos y de las complicaciones hidroelectrolíticas derivadas de la coinfección con C. parvum. Cryptosporydium parvum is an intracellular parasite that infects gastrointestinal epithelium and produces diarrhea that is self-limited in immunocompetent persons but potentially life-threatening in immunocompromised, especially those with the acquired immunodeficiency syndrome (AIDS). C. parvum enteric infection's incidence in a pediatric HIV/AIDS cohort, during a 6 years period, was studied. Clinical and immunologic characteristics of the dual infection were also recorded. Highly active antiretroviral therapy (HAART) was started or continued by all the patients during follow-up. Azithromicyn was used as antiparasitic drug. Cryptosporidiosis incidence was 13.7%; 33 out 240 children showed chronic diarrhea lasting 14 days at least, or recurrent, without dehydration and electrolytic disturbance. Peripheral blood T CD4+ percentage levels of the patients were variable and
Criptosporidiosis intestinal en ni?os con HIV/SIDA
Barboni,Graciela; Candi,Marcela; Villacé,María Inés; Leonardelli,Araceli; Balbaryski,Jeanette; Gaddi,Eduardo;
Medicina (Buenos Aires) , 2008,
Abstract: cryptosporydium parvum is an intracellular parasite that infects gastrointestinal epithelium and produces diarrhea that is self-limited in immunocompetent persons but potentially life-threatening in immunocompromised, especially those with the acquired immunodeficiency syndrome (aids). c. parvum enteric infection's incidence in a pediatric hiv/aids cohort, during a 6 years period, was studied. clinical and immunologic characteristics of the dual infection were also recorded. highly active antiretroviral therapy (haart) was started or continued by all the patients during follow-up. azithromicyn was used as antiparasitic drug. cryptosporidiosis incidence was 13.7%; 33 out 240 children showed chronic diarrhea lasting 14 days at least, or recurrent, without dehydration and electrolytic disturbance. peripheral blood t cd4+ percentage levels of the patients were variable and without relationship with c. parvum presence. viral load levels in 31 out 33 patients were over cut-off at the enteric episode time. mild or moderate eosinophilia were recorded in 23% of the patients and other intestinal parasites were present in 11 children. when the number of enteric episodes were compared with the clinical and immunological patient's status, not significant differences were recorded. haart is the best treatment to improve immune function in hiv patients avoiding potentially fatal complications that accompany acute diarrhea during concomitant infection with c. parvum.
Enfermedad celíaca: diagnóstico a partir de una paciente con clínica de dolor lumbar
González-Tarrío Polo,L.; Rodríguez Villacé,C.; Alonso Val,A.;
Medifam , 2001, DOI: 10.4321/S1131-57682001000200007
Abstract: primary health care plays an important role in the diagnosis of oligosymptomatic celiac disease (cd) witch normaly exhibits symptoms that are frecuent in our daily practice. we present the case of a 41 year-old woman who was diagnosed 15 years ago an irritable bowel syndrome. she presents low back pain that gradually got worse in spite of the treatment prescribed. the blood test shows a severe osteomalacia. the reserch done along with her background point to a malabsorptive problem, leading to a cd diagnosis after the compatible duodenal biopsy and the clinical and histological improvement after gluten suppresion in the diet.
Life cycle, feeding and defecation patterns of Rhodnius ecuadoriensis (Lent & León 1958) (Hemiptera: Reduviidae: Triatominae) under laboratory conditions
Villacís, Anita G;Arcos-Terán, Laura;Grijalva, Mario J;
Memórias do Instituto Oswaldo Cruz , 2008, DOI: 10.1590/S0074-02762008000700011
Abstract: rhodnius ecuadoriensis is the second most important vector of chagas disease (cd) in ecuador. the objective of this study was to describe (and compare) the life cycle, the feeding and defecation patterns under laboratory conditions of two populations of this specie [from the provinces of manabí (coastal region) and loja (andean region)]. egg-to-adult (n = 57) development took an average of 189.9 ± 20 (manabí) and 181.3 ± 6.4 days (loja). mortality rates were high among lojan nymphs. pre-feeding time (from contact with host to feeding initiation) ranged from 4 min 42 s [nymph i (ni)] to 8 min 30 s (male); feeding time ranged from 14 min 45 s (ni)-28 min 25 s (male) (manabí) and from 15 min 25 s (ni)-28 min 57 s (nymph v) (loja). the amount of blood ingested increased significantly with instar and was larger for manabí specimens (p < 0.001). defecation while feeding was observed in manabí specimens from stage nymph iii and in lojan bugs from stage nymph iv. there was a gradual, age-related increase in the frequency of this behaviour in both populations. our results suggest that r. ecuadoriensis has the bionomic traits of an efficient vector of trypanosoma cruzi. together with previous data on the capacity of this species to infest rural households, these results indicate that control of synanthropic r. ecuadoriensis populations in the coastal and andean regions may have a significant impact for cd control in ecuador and northern peru.
The phytoplankton biodiversity of the coast of the state of S?o Paulo, Brazil
Villac, Maria Célia;Cabral-Noronha, Valéria Aparecida de Paula;Pinto, Thatiana de Oliveira;
Biota Neotropica , 2008, DOI: 10.1590/S1676-06032008000300015
Abstract: the objective of this study is to compile the inventory of nearly 100 years of research about the phytoplankton species cited for the coast of the state of s?o paulo, brazil. a state-of-the-art study on the local biodiversity has long been needed to provide a baseline for future comparisons. this type of data is scattered in old scientific journals and in the so-called "grey literature", and are in need of nomenclature updating. twenty-six publications are considered. the earliest sampling record is from 1913 (?) and the most recent from 2002. this checklist compiled from the literature was complemented with primary data collected between august 2004 and july 2006, recent surveys of the surf-zone of 20 beaches located along the coast and of a mariculture farm at the cocanha beach, caraguatatuba. the complete species list includes 572 taxa: most are diatoms (82%), seconded by dinoflagellates (16%), with a minor contribution of silicoflagellates, coccolithophorids, ebriideans and cyanobacteria. the most investigated areas were: ubatuba, s?o sebasti?o, santos and cananéia. the recent surveys have a broader spatial coverage. the objectives of the studies have changed over the years from purely taxonomic to process-oriented investigations. therefore, the longest species lists and most first records for the area were published before the 1980's and later publications, even those in which cell counts were performed, mention only the most abundant/frequent species. electron microscopy was used for the first time in the present surveys, and new records include 38 diatoms, 42 dinoflagellates, 1 silicoflagellate, 1 ebriidean and 2 cyanobacteria. the use and interpretation of this species list require the perception of some constraints. it is not our role to question the identification made by other researchers. on the other hand, the ability to sample, analyze and identify species has evolved over the years and some considerations in this regard are presented.
Auto- and heterotrophic nanoplankton and filamentous bacteria of Guanabara Bay (RJ, Brazil): estimates of cell/filament numbers versus carbon content
Santos, Viviane Severiano;Villac, Maria Célia;Tenenbaum, Denise Rivera;Paranhos, Rodolfo;
Brazilian Journal of Oceanography , 2007, DOI: 10.1590/S1679-87592007000200006
Abstract: variations of nanoplankton (2-20 μm) and filamentous bacteria (diameter: 0.5-2.0 μm) of guanabara bay (rj, brazil) are presented, considering cell density and carbon content of auto- and heterotrophs. our goal is to contribute to future modeling of local trophic dynamics. subsurface water samples were taken weekly during the year 2000 at two sites: urca (close to the entrance, more saline, eutrophic) and ramos (inner area, less saline, hypertrophic). microscopic analysis was done by epifluorescence and cell density was converted to biomass through cell biovolume. total nanoplankton was about 108 cells.l-1 in most samples (>57%), and total filamentous bacteria densities varied from 105 to 108 fil.l-1. autotroph density was one order of magnitude higher at ramos, both for nanoplankton (md: 108cells.l-1 at ramos and 107cells.l-1 at urca) and for filamentous bacteria (md: 106 fil.l-1 at ramos and 105 fil.l-1 at urca). the same was observed for autotrophic biomass (md: 103μgc.l-1 at ramos and 101μgc.l-1 at urca for nanoplankton; md: 28μgc.l-1 at ramos and 1.4μgc.l-1 at urca for filamentous bacteria). the relative contribution of autotrophs increased after conversion to biomass. seasonal variation was conspicuous for filamentous bacteria at both sites and for nanoplankton only at ramos, with maximum autotrophic abundances during the rainy period (spring-summer).
Protozooplankton characterization of two contrasting sites in a tropical coastal ecosystem (Guanabara Bay, RJ)
Gomes, Eli Ana Traversim;Santos, Viviane Severiano dos;Tenenbaum, Denise Rivera;Villac, Maria Célia;
Brazilian Journal of Oceanography , 2007, DOI: 10.1590/S1679-87592007000100004
Abstract: much time and resources have been invested in understanding plankton dynamics in guanabara bay (brazil), but no attention has been devoted to the protozooplankton. to fulfill this lacuna, abundance and composition of protozooplankton were investigated from january to december - 2000 in fortnightly surface water samplings at two distinct water quality sites (urca - closer to the bay entrance, more saline and cleaner waters; ramos - inner reaches, hypereutrophic waters). the density at urca (103 - 105 cell.l-1) was one to three orders of magnitude lower than at ramos (104 - 105 cell.l-1). a seasonal trend for nanoplankton and protozooplankton was more evident at urca, but both sites had lower densities during the colder period. small heterotrophic dinoflagellates (20-30 mm) were dominant in over 50% of the samples. the protozooplankton abundance and composition reflected the distinct trophic conditions states found at the bay. during the wet-warm season, non-oligotrich ciliates were representative of ramos site with gymnodiniaceae dinoflagellates, while tintinnids and heterotrophic dinoflagellates were predominantly found at urca mainly during the dry-cold season. this first descriptive study towards the understanding of the intricate relationships among the microbial food web components reveals that protozooplankton can be a good indicator of water quality conditions at the bay.
Shwachman-Kulczycki score still useful to monitor cystic fibrosis severity
Stollar, Fabíola;Adde, Fabíola Villac;Cunha, Maristela T.;Leone, Claudio;Rodrigues, Joaquim C.;
Clinics , 2011, DOI: 10.1590/S1807-59322011000600010
Abstract: introduction: the shwachman-kulczycki score was the first scoring system used in cystic fibrosis to assess disease severity. despite its subjectivity, it is still widely used. objective: to study correlations among forced expiratory volume in one second (fev1), chest radiography, chest computed tomography, 6-minute walk test, and shwachman-kulczycki score in patients with cystic fibrosis and to test whether the shwachman-kulczycki score is still useful in monitoring the severity of the disease. methods: a cross-sectional prospective study was performed to analyze the correlations (spearman). patients with clinically stable cystic fibrosis, aged 3-21 years, were included. results: 43 patients, 19f/24m, mean age 10.5 + 4.7 years, with a median shwachman-kulczycki score of 70 were studied. the median brasfield and bhalla scores were 17 and 10, respectively. the mean z score for the 6-minute walk test was -1.1 + 1.106 and the mean fev1 was 59 + 26 (as percentage of predicted values). the following significant correlations versus the shwachman-kulczycki score were found: fev1 (r = 0.76), 6-minute walk test (r = 0.71), chest radiography (r = 0.71) and chest computed tomography (r = -0.78). when patients were divided according to fev1, a statistically significantly correlation with the shwachman-kulczycki score was found only in patients with fev1 <70% (r = 0.67). conclusions: the shwachman-kulczycki score remains an useful tool for monitoring the severity of cystic fibrosis, adequately reflecting the functional impairment and chest radiography and tomography changes, especially in patients with greater impairment of lung function. when assessing patients with mild lung disease its limitations should be considered and its usefulness in such patients should be evaluated in larger populations.
Limitations of selective deltamethrin application for triatomine control in central coastal Ecuador
Mario J Grijalva, Anita G Villacís, Sofía Oca?a-Mayorga, César A Yumiseva, Esteban G Baus
Parasites & Vectors , 2011, DOI: 10.1186/1756-3305-4-20
Abstract: Surveys for triatomines revealed peridomestic infestation with Rhodnius ecuadoriensis and Panstrongylus howardi, with infestation indices remaining high during the study (13%, 17%, and 10%, at initial, 6-month, and 12-month visits, respectively), which indicates a limitation of this strategy for triatomine population control. Infestation was found 6 and 12 months after spraying with deltamethrin. In addition, a large number of previously vector-free domestic units also were found infested at the 6- and 12-month surveys, which indicates new infestations by sylvatic triatomines. The predominance of young nymphs and adults suggests new infestation events, likely from sylvatic foci. In addition, infection with Trypanosoma cruzi was found in 65%, 21% and 29% at initial, 6-month and 12-month visits, respectively. All parasites isolated (n = 20) were identified as TcI.New vector control strategies need to be devised and evaluated for reduction of T. cruzi transmission in this region.Chagas disease in Ecuador affects approximately 230,000 people, and 6.2 million people are at risk of infection by Trypanosoma cruzi, its causative agent [1]. In the absence of satisfactory therapy or vaccines against Chagas disease, control of the disease relies primarily on interrupting transmission by eliminating domestic populations of triatomines. Triatomines Rhodnius ecuadoriensis and Panstrongylus howardi are important vectors of Chagas disease in the Manabí province, located on the central coast of Ecuador, and there is evidence of host (vectors and reservoirs) infected with T. cruzi, circulating in the area [2-6].R. ecuadoriensis is widely distributed in Ecuador's central and southern coast [7], its southern Andean region, and in northern Perú [3]. In the coastal region, R. ecuadoriensis is usually found in association with Phytelephas aequatorialis, an endemic palm species, [5,8] and in nests of squirrel (Sciurus stramineus) and bird (Campylorhynchus fasciatus) [6]. In this region, th
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