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1.
Ecotoxicol Environ Saf ; 148: 693-701, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29172150

RESUMO

The increasing presence of pharmaceuticals in aquatic environments in the last decades, derived from human and veterinary use, has become an important environmental problem. Previous studies have shown that ibuprofen (IB) and carbamazepine (CBZ) modify physiological and biochemical processes in Senegalese sole (Solea senegalensis) in a temperature-dependent manner. In other vertebrates, there is evidence that both of these pharmaceuticals interfere with the 'arachidonic acid (AA) cascade', which is responsible for the biosynthesis of numerous enzymes that are involved in the osmoregulatory process. The present work aims to study the temperature-dependent effects of these two pharmaceuticals on several biochemical and molecular parameters in Senegalese sole. Regarding osmoregulation, Na+, K+ -ATPase enzyme activity was determined in the gills, kidney and intestine, and the expressions of both Na+, K+ -ATPase 1α-subunit isoforms (ATP1A1a and ATP1A1b) were quantified in gills. Gill prostaglandin-endoperoxide synthase-2 (PTGS2) gene expression and fatty acid composition were selected to determine the interference of both pharmaceuticals with the AA cascade. Senegalese sole juveniles, acclimatised at 15°C or 20°C, were exposed through intraperitoneal injection to IB (10mg/kg) and CBZ (1mg/kg) for 48h. Non-injected fish (Control) and those injected with the carrier (sunflower oil; S.O.), acclimated at each of the two temperatures, were used for comparison. The results show that IB directly affected the osmoregulatory mechanisms that alter gill and intestine Na+, K+ -ATPase activities. In addition, the copy number of ATP1A1a was higher at 20°C than at 15°C, which could be a direct response to the temperature variation. The gene expression of PTGS2 was affected by neither drug administration nor acclimation temperature. Nevertheless, detailed analysis of AA and eicosapentaenoic acid (EPA) percentages revealed a CBZ-derived effect in the fatty acid composition of the gills.


Assuntos
Aclimatação , Carbamazepina/toxicidade , Ácidos Graxos/metabolismo , Ibuprofeno/toxicidade , Transporte de Íons/efeitos dos fármacos , Temperatura , Poluentes Químicos da Água/toxicidade , Animais , Fenômenos Bioquímicos , Linguados/metabolismo , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Osmorregulação , Prostaglandina-Endoperóxido Sintases/metabolismo , Isoformas de Proteínas , ATPase Trocadora de Sódio-Potássio/metabolismo , Equilíbrio Hidroeletrolítico
2.
Geophys Res Lett ; 44(10): 5167-5177, 2017 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-28781391

RESUMO

A large fraction of atmospheric organic aerosol (OA) originates from natural emissions that are oxidized in the atmosphere to form secondary organic aerosol (SOA). Isoprene (IP) and monoterpenes (MT) are the most important precursors of SOA originating from forests. The climate impacts from OA are currently estimated through parameterizations of water uptake that drastically simplify the complexity of OA. We combine laboratory experiments, thermodynamic modeling, field observations, and climate modeling to (1) explain the molecular mechanisms behind RH-dependent SOA water-uptake with solubility and phase separation; (2) show that laboratory data on IP- and MT-SOA hygroscopicity are representative of ambient data with corresponding OA source profiles; and (3) demonstrate the sensitivity of the modeled aerosol climate effect to assumed OA water affinity. We conclude that the commonly used single-parameter hygroscopicity framework can introduce significant error when quantifying the climate effects of organic aerosol. The results highlight the need for better constraints on the overall global OA mass loadings and its molecular composition, including currently underexplored anthropogenic and marine OA sources.

3.
Vet Res Commun ; 48(3): 1891-1898, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38369611

RESUMO

Trypanosomosis is a tropical disease caused by various protozoan haemoparasites, which affects wild and domestic animals, the latter ones related to worldwide livestock production systems. Species such as Trypanosoma vivax and Trypanosoma evansi have been described using serological and molecular tools in several countries from South and Central America. However, Ecuador presents a relevant knowledge gap in the associated general epidemiology and risk factors of the disease. Therefore, the objective of this study was to determine the seroprevalence of trypanosomosis in cattle from different regions of Ecuador. 745 serum samples from 7 Coastal and 3 Amazon provinces were screened for IgG anti-Trypanosoma spp. antibodies, using an in-house indirect ELISA. The seropositivity was explored and associated with several variables such as sex, age, breed, region, management, and province, using statistical tools. The general seroprevalence of trypanosomosis was 19.1% (95% CI: 16.30-22.1%). The Amazonian provinces of Sucumbíos and Napo and the Coastal province of Esmeraldas presented the highest seroprevalence values of 36.7% (95% CI: 27.67-46.47%), 23.64% (95% CI: 16.06-32.68%) and 25% (95% CI: 15.99-35.94%), respectively. Statistical significance was found for the region, province, and management variables, indicating as relevant risk factors the extensive management and Amazon location of the cattle analyzed. Specific actions should be taken to identify the exact species on reservoirs and susceptible hosts, evaluate the implication of farm management and cattle movement as risk factors, and implement surveillance and treatment plans for affected herds.


Assuntos
Trypanosoma , Animais , Bovinos , Estudos Soroepidemiológicos , Equador/epidemiologia , Fatores de Risco , Feminino , Masculino , Trypanosoma/isolamento & purificação , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/sangue , Tripanossomíase Bovina/epidemiologia , Tripanossomíase Bovina/sangue , Tripanossomíase/veterinária , Tripanossomíase/epidemiologia , Tripanossomíase/parasitologia , Anticorpos Antiprotozoários/sangue , Ensaio de Imunoadsorção Enzimática/veterinária
4.
Vet Parasitol Reg Stud Reports ; 37: 100824, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36623904

RESUMO

Trypanosoma theileri is a cosmopolitan opportunistic haemoparasite described in wild and domestic ruminants, and also in arthropod vectors. The presence of this parasite has been reported in several South American countries, including Amazonian regions. Despite the importance of livestock production, Ecuador possesses scarce studies about trypanosomosis and no T. theileri reports in its territory. Here, we showed molecular evidences of the presence of T. theileri in cattle from a province located in the Ecuadorian Amazon. Bovine blood samples were collected from 2014 to 2019, during campaigns to detect haemoparasites in the Ecuadorian provinces of Orellana and Sucumbíos. DNA was extracted from the buffy coat and used in PCR assays with three different molecular markers, ITS1, 18S and Cathepsin L-like. T. theileri was detected only in the Sucumbíos province, with a specific molecular prevalence of 8.6% (3/35) using the three primers and an additional animal detected as positive (11.4% prevalence) only by the ITS1 marker. DNA sequences derived from the generated amplicons were subjected to phylogenetics maximum parsimony and maximum likelihood analysis, which indicate the presence of TthI and TthII genotypes circulating in the evaluated animals. Molecular surveillance should be continually implemented in Ecuador in order to deepen the epidemiological and evolutionary knowledge about T. theileri as well other haemoparasites in the amazon parts of the country.


Assuntos
Doenças dos Bovinos , Trypanosoma , Tripanossomíase , Bovinos , Animais , Equador/epidemiologia , Doenças dos Bovinos/parasitologia , Trypanosoma/genética , Tripanossomíase/epidemiologia , Tripanossomíase/veterinária , Tripanossomíase/parasitologia , Ruminantes
5.
Eur Psychiatry ; 24(5): 287-96, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19195847

RESUMO

BACKGROUND: The electronic Schizophrenia Treatment Adherence Registry (e-STAR) is a prospective, observational study of patients with schizophrenia designed to evaluate long-term treatment outcomes in routine clinical practice. METHODS: Parameters were assessed at baseline and at 3 month intervals for 2 years in patients initiated on risperidone long-acting injection (RLAI) (n=1345) or a new oral antipsychotic (AP) (n=277; 35.7% and 36.5% on risperidone and olanzapine, respectively) in Spain. Hospitalization prior to therapy was assessed by a retrospective chart review. RESULTS: At 24 months, treatment retention (81.8% for RLAI versus 63.4% for oral APs, p<0.0001) and reduction in Clinical Global Impression Severity scores (-1.14 for RLAI versus -0.94 for APs, p=0.0165) were significantly higher with RLAI. Compared to the pre-switch period, RLAI patients had greater reductions in the number (reduction of 0.37 stays per patient versus 0.2, p<0.05) and days (18.74 versus 13.02, p<0.01) of hospitalizations at 24 months than oral AP patients. CONCLUSIONS: This 2 year, prospective, observational study showed that, compared to oral antipsychotics, RLAI was associated with better treatment retention, greater improvement in clinical symptoms and functioning, and greater reduction in hospital stays and days in hospital in patients with schizophrenia. Improved treatment adherence, increased efficacy and reduced hospitalization with RLAI offer the opportunity of substantial therapeutic improvement in schizophrenia.


Assuntos
Antipsicóticos/administração & dosagem , Adesão à Medicação , Risperidona/administração & dosagem , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Administração Oral , Adulto , Antipsicóticos/efeitos adversos , Benzodiazepinas/administração & dosagem , Benzodiazepinas/efeitos adversos , Preparações de Ação Retardada , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Injeções Intramusculares , Assistência de Longa Duração , Masculino , Pessoa de Meia-Idade , Olanzapina , Readmissão do Paciente/estatística & dados numéricos , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Sistema de Registros , Risperidona/efeitos adversos
6.
Anal Chim Acta ; 1051: 103-109, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30661606

RESUMO

Gas chromatography coupled to a quadrupole time-of-flight mass analyzer (QTOF) with an atmospheric pressure chemical ionization (APCI) source has been tested to study the ionization and mass spectrometric behavior of long-chain and very long-chain polyunsaturated fatty acids (LC-PUFAs, C18-24; VLC-PUFAs, >C24). The protonated molecule ([M+H]+), measured at accurate mass, became the base peak of the spectrum for all the studied compounds and was promoted by the addition of water into the source. This fact overcame the existing difficulties for the identification of VLC-PUFAs when using an electron ionization source (EI). The extensive fragmentation of PUFAs in this source is the main drawback due to the fact that since reference standards are not commercially available, final identification relies on retention time estimation. The application of GC-APCI-QTOF to the screening of lipid extracts from the eyes of different fish species added confidence to the identification of several VLC-PUFAs. Further investigation of ion ratios allowed to predict the position of key double bonds enabling the classification of VLC-PUFAs as ω3 or ω6 compounds. VLC-PUFAs spectra found in biological samples were compared to those obtained from corresponding peaks found in heterologous expression experiments of fish's Elovl4.


Assuntos
Pressão Atmosférica , Ésteres/química , Ácidos Graxos/análise , Ácidos Graxos/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Animais , Ácidos Graxos/isolamento & purificação , Peixes , Reprodutibilidade dos Testes
7.
Environ Sci Process Impacts ; 21(4): 635-649, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30888351

RESUMO

Perfluoroalkyl acids (PFAAs) are persistent organic pollutants found throughout the world's oceans. Previous research suggests that long-range atmospheric transport of these substances may be substantial. However, it remains unclear what the main sources of PFAAs to the atmosphere are. We have used a laboratory sea spray chamber to study water-to-air transfer of 11 PFAAs via sea spray aerosol (SSA). We observed significant enrichment of all PFAAs relative to sodium in the SSA generated. The highest enrichment was observed in aerosols with aerodynamic diameter < 1.6 µm, which had aerosol PFAA concentrations up to ∼62 000 times higher than the PFAA water concentrations in the chamber. In surface microlayer samples collected from the sea spray chamber, the enrichment of the substances investigated was orders of magnitude smaller than the enrichment observed in the aerosols. In experiments with mixtures of structural isomers, a lower contribution of branched PFAA isomers was observed in the surface microlayer compared to the bulk water. However, no clear trend was observed in the comparison of structural isomers in SSA and bulk water. Using the measured enrichment factors of perfluorooctanoic acid and perfluorooctane sulfonic acid versus sodium we have estimated global annual emissions of these substances to the atmosphere via SSA as well as their global annual deposition to land areas. Our experiments suggest that SSA may currently be an important source of these substances to the atmosphere and, over certain areas, to terrestrial environments.


Assuntos
Aerossóis/análise , Monitoramento Ambiental/métodos , Fluorocarbonos/análise , Água do Mar/química , Poluentes Químicos da Água/análise
8.
Aquat Toxicol ; 88(1): 53-61, 2008 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-18433895

RESUMO

This study evaluates the toxic effects of the organophosphate pesticide (OP) dichlorvos to the endangered Iberian toothcarp (Aphanius iberus). To this end, the lethal toxicity of dichlorvos based on 96h-LC50 bioassays was determined in saline water (50g/L), and in vivo effects of dichlorvos on cholinesterase (ChE) activity were investigated in adult female and male specimens. The 96h-LC50 value determined by probit analysis was 3.17mg/L (95% confidence limits: 1.34-3.97). The characterisation of the ChE using different substrates and specific inhibitors was also carried out in head and muscle tissues. Acetylthiocholine was the substrate preferred by both head and muscle ChE in males and females. Eserine sulphate and BW284C51 significantly inhibited both head and muscle enzyme activity at low concentrations (muM range), and iso-OMPA had no significant effect. These results indicate that in the head and muscle the predominant ChE form is acetylcholinesterase (AChE) for both sexes. The kinetic parameters for ChE activity (Km and Vmax) were similar in both sexes. The 96h-LC50 value obtained for adult specimens of Iberian toothcarp was 3.17mg/L. ChE activity in head and body tissues of both sexes was significantly inhibited in all concentrations tested (0.5, 1, 2 and 4mg/L) after "in vivo" dichlorvos exposure. However, Iberian toothcarp was able to tolerate high concentrations of dichlorvos, and resist high levels of brain and muscle ChE inhibition without mortality. Both ChE inhibition and recovery followed a similar time-course pattern in response to sub-lethal exposure to dichlorvos (1mg/L), and the enzyme activity did not return to control levels after 96h in clean water. The results of this study show that ChE activity is a good biomarker of exposure to OP in the Iberian toothcarp adults.


Assuntos
Inibidores da Colinesterase/toxicidade , Colinesterases/metabolismo , Diclorvós/toxicidade , Peixes Listrados/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Feminino , Masculino , Músculos/efeitos dos fármacos , Músculos/enzimologia , Análise de Sobrevida
12.
Rev Esp Anestesiol Reanim (Engl Ed) ; 65(4): 204-208, 2018 Apr.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-29336785

RESUMO

Multimodal anaesthesia, combining epidural catheter and general anaesthesia, is a common technique in thoracic surgery, however, epidural catheter placement is not always possible. Recently, erector spinae plane block has been described, which provides analgesia like that of the epidural block, although unilateral, and which has been used in various procedures at thoracic level. At present, there are no studies comparing the efficacy or safety of this block with those commonly used in thoracic surgery. However, its safety profile and contraindications seem different from those of the epidural catheter, since its placement is done under ultrasound view, the needle introduction is done in plane and the ultrasound target, the transverse process, is easily identifiable and is relatively remote from major neural or vascular structures and the pleura. Unlike other blockages made by anatomical references, erector spinae plane block can be done with the patient in different positions. We describe our experience with erector spinae plane block as part of a multimodal anaesthetic approach in thoracic surgery.


Assuntos
Bloqueio Nervoso/métodos , Dor Pós-Operatória/prevenção & controle , Cirurgia Torácica Vídeoassistida , Adulto , Idoso , Analgesia Epidural , Carcinoma Adenoide Cístico/cirurgia , Carcinoma Broncogênico/cirurgia , Carcinoma de Células Escamosas/cirurgia , Contraindicações de Procedimentos , Feminino , Humanos , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Ultrassonografia de Intervenção
13.
Neotrop Entomol ; 46(6): 622-630, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28258352

RESUMO

Blood-feeding status, gonotrophic cycle, and survival rates of Aedes (Stegmyia) aegypti (L.) was investigated in catholic churches from Merida, Yucatan. Female Ae. aegypti were caught using backpack aspirator during 25 consecutive days in rainy (2015) and dry season (2016). Blood-feeding status was determined by external examination of the abdomen and classified as unfed, fed, and gravid. Daily changes in the parous-nulliparous ratio were recorded, and the gonotrophic cycle length was estimated by a time series analysis. Also, was observed the vitellogenesis to monitoring egg maturity. In total, 408 females Ae. aegypti were caught, and there was a significant difference in the number of females collected per season (Z = -6.729, P ≤ 0.05). A great number was caught in the rainy season (n = 329). In the dry season, 79 females were caught, which the fed females were twice greatest than the unfed. The length of gonotrophic cycle was estimated on the base of a high correlation coefficient value appearing every 4 days in rainy at 26.7 ± 1.22°C, and 3 days in dry season at 29.8 ± 1.47°C. The daily survival rate of the Ae. aegypti population was higher in both seasons, 0.94 and 0.93 for the rainy and dry season, respectively. The minimum time estimated for developing mature eggs after blood feeding was similar in both seasons (3.5 days in rainy versus 3.25 days in dry). The measurement of the vectorial capacity of Ae. aegypti in catholic churches could help to understand the dynamics of transmission of arboviruses in sites with high human aggregation.


Assuntos
Aedes/fisiologia , Mosquitos Vetores/fisiologia , Animais , Comportamento Alimentar , Feminino , Humanos , Mordeduras e Picadas de Insetos/sangue , México , Reprodução
14.
Sci Total Environ ; 366(1): 148-53, 2006 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-16797674

RESUMO

In order to reveal the efficacy of the Artemia cysts chorion as barrier to the organophosphorus pesticide chlorpyrifos, whole and decapsulated cysts have been exposed to 10 mg L(-1) chlorpyrifos in sea water during hydration and hatching phase, separately. The concentration of chlorpyrifos in capsulated and decapsulated cysts after exposure has been determined in order to elucidate the efficacy of chorion as protection to the embryo. The results obtained demonstrate the ability of the cysts chorion to obstruct the pass of chlorpyrifos molecules through this protection structure. Thus, the concentration of chlorpyrifos in exposed decapsulated cysts is higher than in exposed whole cysts. Moreover, after removing the chorion of exposed cysts, the concentration of chlorpyrifos in the embryo was lower than that of cysts exposed, what would demonstrate the retention of chlorpyrifos molecules by the shell. Hatching was not severely affected by exposure to the insecticide whereas survival at 44 h of the nauplii exposed to chlorpyrifos was significantly different from the controls. Survival of nauplii hatched from exposed decapsulated cysts was higher than that from those hatched from exposed whole cysts, probably because of the lower vitality of the latter, due to depletion of energy reserves during hatching.


Assuntos
Clorpirifos/toxicidade , Crustáceos/efeitos dos fármacos , Praguicidas/toxicidade , Taxa de Sobrevida , Poluentes Químicos da Água/toxicidade , Animais , Clorpirifos/farmacocinética , Crustáceos/embriologia , Crustáceos/fisiologia , Monitoramento Ambiental , Peixes , Cadeia Alimentar , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Compostos Organofosforados/farmacocinética , Compostos Organofosforados/toxicidade , Praguicidas/farmacocinética , Água do Mar , Fatores de Tempo , Poluentes Químicos da Água/farmacocinética
15.
Infect Genet Evol ; 36: 456-461, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26296606

RESUMO

Aedes aegypti and Aedes albopictus, two important vectors of the dengue and chikungunya viruses to humans, often come in contact in their invasive ranges. In these circumstances, a number of factors are thought to influence their population dynamics, including resource competition among the larval stages, prevailing environmental conditions and reproductive interference in the form of satyrization. As the distribution and abundance of Ae. aegypti and Ae. albopictus have profound epidemiological implications, understanding the competitive interactions that influence these patterns in nature is important. While evidence for resource competition and environmental factors had been gathered from the field, the evidence for reproductive interference, though strongly inferred through laboratory trials, remained sparse (one small-scale field trial). In this paper we demonstrate that low rates (1.12-3.73%) of interspecific mating occur in nature among populations of these species that have co-existed sympatrically from 3 to 150yrs. Finally this report contributes a new species-specific primer set for identifying the paternity of sperm extracted from field collected specimens.


Assuntos
Aedes/fisiologia , Reprodução , Comportamento Sexual Animal , Aedes/classificação , Animais , Feminino , Aptidão Genética , Masculino , Especificidade da Espécie
16.
Aquat Toxicol ; 161: 208-20, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25723047

RESUMO

The genus Artemia consists of several bisexual and parthenogenetic sibling species. One of them, A. franciscana, originally restricted to the New World, becomes invasive when introduced into ecosystems out of its natural range of distribution. Invasiveness is anthropically favored by the use of cryptobiotic eggs in the aquaculture and pet trade. The mechanisms of out-competition of the autochthonous Artemia by the invader are still poorly understood. Ecological fitness may play a pivotal role, but other underlying biotic and abiotic factors may contribute. Since the presence of toxicants in hypersaline aquatic ecosystems has been documented, our aim here is to study the potential role of an organophosphate pesticide, chlorpyrifos, in a congeneric mechanism of competition between the bisexual A. franciscana (AF), and one of the Old World parthenogenetic siblings, A. parthenogenetica (PD). For this purpose we carried out life table experiments with both species, under different concentrations of the toxicant (0.1, 1 and 5µg/l), and analyzed the cholinesterase inhibition at different developmental stages. The results evidence that both, AF and PD, showed an elevated tolerance to high ranges of chlorpyrifos, but AF survived better and its fecundity was less affected by the exposure to the pesticide than that of PD. The higher fecundity of AF is a selective advantage in colonization processes leading to its establishment as NIS. Besides, under the potential selective pressure of abiotic factors, such as the presence of toxicants, its higher resistance in terms of survival and biological fitness also indicates out-competitive advantages.


Assuntos
Artemia/efeitos dos fármacos , Espécies Introduzidas , Poluentes Químicos da Água/toxicidade , Animais , Clorpirifos/toxicidade , Resistência a Medicamentos/fisiologia , Especificidade da Espécie
17.
Am J Trop Med Hyg ; 64(1-2): 84-92, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11425168

RESUMO

From 1997-1998, we investigated the possible continuous circulation of epizootic Venezuelan equine encephalitis (VEE) virus suggested by a 1983 subtype IC interepizootic mosquito isolate made in Panaquire, Miranda State, Venezuela. The study area was originally covered by lowland tropical rainforest but has been converted into cacao plantations. Sentinel hamsters, small mammal trapping, mosquito collections, and human serosurveys were used to detect active or recent virus circulation. Six strains of subtype ID VEE virus were isolated from hamsters that displayed no apparent disease. Four other arboviruses belonging to group A (Togaviridae: Alphavirus), two Bunyamwera group (Bunyaviridae), and three Gamboa group (Bunyaviridae) arboviruses were also isolated from hamsters, as well as 8 unidentified viruses. Venezuelan equine encephalitis-specific antibodies were detected in 5 small mammal species: Proechimys guairae, Marmosa spp., and Didelphis marsupialis. Mosquito collections comprised of 38 different species, including 8 members of the subgenus Culex (Melanoconion), did not yield any virus isolates. Sera from 195 humans, either workers in the cacao plantation or nearby residents, were all negative for VEE virus antibodies. Sequences of 1,677 nucleotides from the P62 gene of 2 virus isolates indicated that they represent a subtype ID lineage that is distinct from all others characterized previously, and are unrelated to epizootic VEE emergence.


Assuntos
Culicidae , Vírus da Encefalite Equina Venezuelana/isolamento & purificação , Encefalomielite Equina Venezuelana/epidemiologia , Encefalomielite Equina Venezuelana/prevenção & controle , Mamíferos , Vigilância de Evento Sentinela , Zoonoses/epidemiologia , Animais , Cricetinae , Humanos , Clima Tropical , Venezuela/epidemiologia
18.
Am J Trop Med Hyg ; 65(6): 738-46, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11791968

RESUMO

During field studies of enzootic Venezuelan equine encephalitis (VEE) viruses associated with epizootic emergence, a large number of virus isolates were made in sylvatic foci of Venezuela and Colombia. To rapidly characterize these isolates, antigenic subtypes were determined by means of immunofluorescence and by single-strand conformational polymorphism (SSCP) analysis by use of an 856-bp fragment from the P62 gene, which we used to distinguish genetic variants. Representative isolates were sequenced to assess the sensitivity of SSCP to detect genetic differences. The SSCP analysis distinguished isolates differing by as little as 1 nucleotide; overall, differences of > or = 1 nucleotide were recognized 89% of the time, and the sensitivity to distinguish strains that differed by only 1 or 4 nucleotides was 17 and 57%, respectively. Phylogenetic analyses of representative sequences showed that all recent isolates from the Catatumbo region of western Venezuela and the middle Magdalena Valley of Colombia were closely related to epizootic subtype IAB and IC strains; strains from Yaracuy and Miranda States were more distantly related. Cocirculation of the same virus genotype in both Colombian and Venezuelan foci indicated that these viruses are readily transported between enzootic regions separated by > 300 km. The SSCP analysis appears to be a simple, fast, and relatively efficient method of screening VEE virus isolates to identify meaningful genetic variants.


Assuntos
Vírus da Encefalite Equina Venezuelana/genética , Encefalomielite Equina Venezuelana/epidemiologia , Polimorfismo Conformacional de Fita Simples , Aedes , Animais , Colômbia/epidemiologia , Cricetinae , Culex , Primers do DNA , Vírus da Encefalite Equina Venezuelana/classificação , Imunofluorescência , Humanos , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Venezuela/epidemiologia
19.
Behav Brain Res ; 72(1-2): 189-96, 1995 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-8788871

RESUMO

The possibility that endogenous serotonin (5-hydroxytryptamine, 5-HT) participates in alteration of the blood-brain barrier (BBB) following short-term forced swimming (FS) exercise was examined in a rat model. Subjection of conscious young (age 8-9 weeks, 80-90 g) animals to continuous FS (at a water temperature of 30 +/- 1 degrees C) for 30 min, increased the permeability of the BBB to Evans blue albumin (EBA) and 131I-sodium in six and nine brain regions, respectively. The EBA staining was noted in posterior cingulate cortex, parietal, occipital cortices, cerebellar vermis, medial lateral cerebellar cortices and dorsal surface of hippocampus. In addition to these brain regions, the BBB permeability to 131I-sodium was further extended to caudate nucleus, thalamus and hypothalamus. This effect of FS on the BBB permeability was absent in adult (age 24-30 weeks, 300-400 g) animals. Measurement of 5-HT showed a profound increase of plasma and brain in young rats by 180% and 250%, respectively, from the control group. Adult animals showed only a minor increase in brain and plasma 5-HT levels. In young animals, pretreatment with p-CPA (a 5-HT synthesis inhibitor) and indomethacin (a prostaglandin synthesis inhibitor) prevented the FS induced increase in BBB permeability and 5-HT levels. Destruction of serotonergic neurons with 5,7-dihydroxytryptamine (5,7-DHT) reduced the breakdown of the BBB and attenuated the brain 5-HT level without affecting the plasma 5-HT. Cyproheptadine, ketanserin (5-HT2 receptor antagonists) and vinblastine (a vesicular transport inhibitor) prevented the increased permeability of the BBB alone. The plasma and brain 5-HT continued to remain high. These observations suggest that (i) 5-HT plays an important role in the breakdown of BBB permeability in FS, (ii) this effect of 5-HT on BBB permeability is mediated by 5-HT2 receptors, and (iii) FS induced increase in BBB permeability is age dependent.


Assuntos
Barreira Hematoencefálica/fisiologia , Serotonina/fisiologia , Estresse Psicológico/fisiopatologia , 5,7-Di-Hidroxitriptamina/farmacologia , Envelhecimento/fisiologia , Animais , Antineoplásicos Fitogênicos/farmacologia , Pressão Sanguínea/fisiologia , Química Encefálica/fisiologia , Ciproeptadina/farmacologia , Azul Evans , Feminino , Fenclonina/farmacologia , Indometacina/farmacologia , Radioisótopos do Iodo , Ketanserina/farmacologia , Masculino , Ratos , Serotonina/metabolismo , Serotoninérgicos/farmacologia , Antagonistas da Serotonina/farmacologia , Estresse Psicológico/psicologia , Natação , Vimblastina/farmacologia
20.
Vector Borne Zoonotic Dis ; 1(3): 219-30, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12653150

RESUMO

The distribution of the sylvatic subtype ID Venezuelan equine encephalitis (VEE) viruses in the lowland tropical forests of western Venezuela was investigated using remote sensing and geographic information system technologies. Landsat 5 Thematic Mapper satellite imagery was used to study the reflectance patterns of VEE endemic foci and to identify other locations with similar reflectance patterns. Enzootic VEE virus variants isolated during this study are the closest genetic relatives of the epizootic viruses that emerged in western Venezuela during 1992-1993. VEE virus surveillance was conducted by exposing sentinel hamsters to mosquito bites and trapping wild vertebrates in seven forests identified and located by means of the satellite image. We isolated VEE viruses from 48 of a total of 1,363 sentinel hamsters in two of the forests on six occasions, in both dry and wet seasons. None of the 12 small vertebrates captured in 8,190 trap-nights showed signs of previous VEE virus infection. The satellite image was classified into 13 validated classes of land use/vegetation using unsupervised and supervised techniques. Data derived from the image consisted of the raw digital values of near- and mid-infrared bands 4, 5, and 7, derived Tasseled Cap indices of wetness, greenness, and brightness, and the Normalized Difference Vegetation Index. Digitized maps provided ancillary data of elevation and soil geomorphology. Image enhancement was applied using Principal Component Analysis. A digital layer of roads together with georeferenced images was used to locate the study sites. A cluster analysis using the above data revealed two main groups of dense forests separated by spectral properties, altitude, and soil geomorphology. Virus was isolated more frequently from the forest type identified on flat flood plains of main rivers rather than the forest type found on the rolling hills of the study area. The spatial analysis suggests that mosquitoes carrying the enzootic viruses would reach 82-97% of the total land area by flying only 1-3 km from forests. We hypothesize that humans within that area are at risk of severe disease caused by enzootic ID VEE viruses. By contrast, equines could actually become naturally vaccinated, thus preventing the local emergence of epizootic IC VEE virus strains and protecting humans indirectly.


Assuntos
Culicidae/virologia , Reservatórios de Doenças/veterinária , Vírus da Encefalite Equina Venezuelana/isolamento & purificação , Encefalomielite Equina Venezuelana/epidemiologia , Insetos Vetores/virologia , Animais , Análise por Conglomerados , Cricetinae , Culicidae/fisiologia , Sistemas de Informação Geográfica , Humanos , Insetos Vetores/fisiologia , Mesocricetus , Vigilância da População , Estações do Ano , Árvores , Venezuela/epidemiologia , Zoonoses
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