99 research outputs found
Limited risk of Zika virus transmission by five Aedes albopictus populations from Spain
Background: Aedes albopictus, the Asian tiger mosquito, is an exotic invasive species in Europe. It has substantial
public health relevance due to its potential role in transmitting several human pathogens. Out of the European coun‑
tries, Spain has one of the highest risk levels of autochthonous arbovirus transmission due to both the high density of
Ae. albopictus and the extensive tourist infux from vector-endemic areas. This study aims to investigate the suscep‑
tibility of fve Ae. albopictus populations from mainland Spain and the Balearic Islands to a Brazilian Zika virus (ZIKV)
strain.
Methods: The F1 generation of each Ae. albopictus population was orally challenged with a ZIKV-infected blood meal
(1.8×106 PFU/ml). At 7 and 14 days post-infection (dpi), mosquito bodies (thorax and abdomen) and heads were
individually analysed through RT-qPCR to determine the infection rate (IR) and dissemination rate (DR), respectively.
The saliva of infected mosquitoes was inoculated in Vero cells and the transmission rate was assessed by plaque assay
or RT-qPCR on ~33 individuals per population.
Results: The IR and DR ranged between 12–88%, and 0–60%, respectively, suggesting that ZIKV is capable of cross‑
ing the midgut barrier. Remarkably, no infectious viral particle was found in saliva samples, indicating a low ability of
ZIKV to overcome the salivary gland barrier. A subsequent assay revealed that a second non-infective blood meal 48 h
after ZIKV exposure did not infuence Ae. albopictus vector competence.
Conclusions: The oral experimental ZIKV infections performed here indicate that Ae. albopictus from Spain become
infected and disseminate the virus through the body but has a limited ability to transmit the Brazilian ZIKV strain
through biting. Therefore, the results suggest a limited risk of autochthonous ZIKV transmission in Spain by Ae.
albopictusinfo:eu-repo/semantics/publishedVersio
Lack of association between the 5-HTTLPR and positive screening for mental disorders among children exposed to urban violence and maltreatment
Objective: To ascertain whether genetic variations in the serotonin transporter gene (5-HTTLPR 44-bp insertion/deletion polymorphism) influence an increase in depressive and anxiety symptoms in children and adolescents exposed to high levels of violence. Methods: Saliva samples were collected from a group of children who were working on the streets and from their siblings who did not work on the streets. DNA was extracted from the saliva samples and analyzed for 5-HTTLPR polymorphism genotypes. Results: One hundred and seventy-seven children between the ages of 7 and 14 years were analyzed (114 child workers and 63 siblings). Data on socioeconomic conditions, mental symptoms, and presence and severity of maltreatment and urban violence were collected using a sociodemographic inventory and clinical instruments. There was no positive correlation between the 5-HTTLPR polymorphism and presence of mental symptoms in our sample, although the children were exposed to high levels of abuse, neglect, and urban violence. Conclusions: Despite previous studies that associated adult psychiatric disorders with the 5-HTTLPR polymorphism and a history of childhood maltreatment, no such association was found in this sample of children at risk.Universidade Federal de São Paulo (UNIFESP) Department of PsychiatryOcular Genetic InstituteCollege of Public Health, USPUniversidade de São Paulo (USP) Institute of Mathematics and StatisticsKing's College London Institute of Psychiatry Health Service and Population Research DepartmentUNIFESP, Department of PsychiatrySciEL
Bionomics of Culex quinquefasciatus within urban areas of Rio de Janeiro, Southeastern Brazil
OBJECTIVE: To evaluate density, parity rates, daily survival and longevity of natural populations of Culex quinquefasciatus in three neighborhoods with distinct socio-economic and infrastructure profiles. METHODS: Mosquito collections of the Culex quinquefasciatus species were performed weekly during two four month periods, from August to November 2008 (spring) and March to June 2009 (fall), in a favela (slum), a suburban area and a middle class area of Rio de Janeiro, Southeastern Brazil. Collections were performed with backpack aspirators, in 20 randomly selected houses in each area per week, during 15-20 minutes per house. Ovaries were removed from captured females and classified as initial, intermediary or final stage. Furthermore, females were dissected for determination of parity based on the condition of the tracheal system. Mosquito survival rate and longevity were estimated on a per month basis for each neighborhood. RESULTS: We collected a total of 2,062 Culex quinquefasciatus, but monthly vector density was not correlated with temperature and rainfall. We dissected the ovaries of 625 Culex quinquefasciatus, and overall, there was a higher proportion of nulliparous females during the dryer months, while gravid females were more frequent in rainy months. In the middle class neighborhood, the parity rate reached up to 93.75% with survivorship of 0.979. Lower parity and survival rates were obtained in the suburban area (as low as 36.4% parity and 0.711 daily survival). Up to 84.7% of Culex quinquefasciatus females could survive the eight day period needed to complete West Nile Virus incubation. CONCLUSIONS: The survival rate of Culex quinquefasciatus varied significantly between the neighborhoods. This suggests that vectorial capacity and disease transmission risk may vary greatly between different urban areas, which is potentially useful information for vector control programs
Exposure to maltreatment and urban violence in children working on the streets in São Paulo, Brazil: factors associated with street work
Objective: To quantitatively study the exposure to childhood maltreatment and urban violence in children from families with at least one child working on the streets and to investigate the relationship between these factors and street work. Methods: Families who participated in a nongovernmental organization (NGO) program to eliminate child labor were included. Data concerning sociodemographic characteristics, punishment methods used in the family environment against the children, five types of abuse and neglect perpetrated by the caregivers, urban violence exposure and family functioning were collected. Results: The sample included 126 children who were working on the streets and 65 siblings who were not working on the streets. Caregivers reported high levels of severe physical punishment. The children reported high levels of abuse and neglect, and high levels of urban violence exposure. The families showed a predominance of dysfunctional and unsatisfactory relationships. A multiple logistic regression model showed that age older than 12 years and severe physical punishment at home were associated with street work. Conclusion: Interventions to decrease the risk of child street work should be family-focused and should aim to reduce violence in the family environment.Universidade Federal de São Paulo (UNIFESP) Department of PsychiatryUniversidade Estadual de São Paulo (UNESP) Mathematics and Statistics InstituteUniversidade Presbiteriana Mackenzie Graduate Program in Developmental DisordersPontifÃcia Universidade Católica do Rio Grande do Sul (PUCRS) Graduate Department of PsychologyRUKHA Institute and Center for Studies and Research in Neuropsychoanalysis (CEINP)UNIFESP, Department of PsychiatrySciEL
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Aedes aegypti oviposition-sites choice under semi-field conditions
Vector control is still the recommended approach to avoid arbovirus outbreaks. Herein, we investigate oviposition preferences of Aedes aegypti (Diptera: Culicidae) females under a semi-field structure Rio de Janeiro, Brazil. For that, in Experiment 1, we used two settings: ‘Single items’, which included as containers drain, beer bottle, bucket, car tyre, water tank, and a potted Peace Lily (Spathiphyllum wallisii) in a saucer with water, or ‘Multiple containers’, as an urban simulation, in which one drain, two additional beer bottles, and an extra plant pot saucer were added. Experiment 2 (sensory cues) used five variations of potted plant, each one varying in the range of sensory cues known to attract gravid females to oviposition containers. Our results indicate that gravid Ae. aegypti prefer to oviposit close to the ground and in open water containers with organic compounds from plant watering. Domestic large artificial containers containing tap water received significantly fewer eggs, except for the car tyre, which exhibited as many eggs as the potted plant. We also show that visual (potted plant shape) and olfactory clues (odour of the plant or from water containing organic matter) were equally attractive separately as were these stimuli together
Parámetros de calidad en sueros controles utilizados en Laboratorios ClÃnicos del estado Zulia, Venezuela |Quality parameters in control sera used in Clinical Laboratories of Zulia state, Venezuela
El aseguramiento de la calidad constituye un aspecto esencial que garantiza resultados fiables en los análisis clÃnicos. Por tal motivo, este estudio, descriptivo y transversal, tiene como propósito evaluar los parámetros de calidad en materiales de control empleados en laboratorios clÃnicos del estado Zulia, Venezuela. Se valoraron sueros controles de cinco casas comerciales, a los cuales se les determinaron variables fisicoquÃmicas, calidad bacteriológica e inmunológica. Para ésta última se evaluó la presencia de anticuerpos contra HIV, Hepatitis B y C. Finalmente, se estableció asociación entre los datos bioquÃmicos obtenidos y los aportados por el fabricante. Siguiendo los lineamientos de la Confederación Latinoamericana de BioquÃmica ClÃnica; al considerar aspectos fisicoquÃmicos, todos los resultados mostraron ser satisfactorios para tiempo de reconstitución. En cuanto a turbidez, un nivel de suero control (7,14%) reflejó valores elevados y tres presentaron un pH inferior al intervalo establecido (21,42%). La totalidad de los materiales de control mostraron ser negativos desde el punto de vista bacteriológico e inmunológico. Al asociar las medias aportadas por el fabricante y las obtenidas en esta investigación, se empleó el Porcentaje de Desviación o DesvÃo Relativo Porcentual (DRP); resultando que 35,7% de los lotes superan el lÃmite de aceptabilidad del 10%, lo cual sugiere al fabricante la realización de estudios que consideren la reasignación de los lÃmites permisibles de error. Estos resultados constituyen un punto de partida para futuras investigaciones que permitan verificar que los materiales de control en los laboratorios clÃnicos cumplan con los estándares de calidad para asà asegurar la confiabilidad de los análisis clÃnicos. Palabras clave: QuÃmica clÃnica. ABSTRACT The quality assurance is an essential aspect that ensures reliable results in the clinical analysis. For this reason, this study, descriptive and transverse, is aimed at evaluating the quality parameters in control materials employed in clinical laboratories of Zulia State, Venezuela. Control sera of five commercial houses were evaluated, through physico chemical variables and bacteriological and immunological quality. The latter involved the determination of antibodies for HIV, Hepatitis B and C. Finally, an association was established between the biochemical data obtained with those provided by the manufacturer. Following the guidelines of the Latin American Confederation of Clinical Biochemistry; when considering physical and chemical aspects, all the results were satisfactory for reconstitution time. With regard to turbidity, one level of control sera (7,14%) reflected high values and three (21,4%) presented a pH lower than the set range. All control materials were negative from bacteriological and immunological point of view By associating the means provided by the manufacturer and those obtained in this research, we use the percentage of deviation or Percentage Relative Deviation, resulting that 35.7% of the lots exceed the limit of acceptability of 10%, which suggests that the manufacturer should study the reallocation of the permissible limits of error. These results are a starting point for future research that enable the verification that the control materials in clinical laboratories comply with quality standards to ensure the reliability of the clinical analysis. Key words: Clinical chemistry
Impairment of the Plasmodium falciparum Erythrocytic Cycle Induced by Angiotensin Peptides
Plasmodium falciparum causes the most serious complications of malaria and is a public health problem worldwide with over 2 million deaths each year. The erythrocyte invasion mechanisms by Plasmodium sp. have been well described, however the physiological aspects involving host components in this process are still poorly understood. Here, we provide evidence for the role of renin-angiotensin system (RAS) components in reducing erythrocyte invasion by P. falciparum. Angiotensin II (Ang II) reduced erythrocyte invasion in an enriched schizont culture of P. falciparum in a dose-dependent manner. Using mass spectroscopy, we showed that Ang II was metabolized by erythrocytes to Ang IV and Ang-(1–7). Parasite infection decreased Ang-(1–7) and completely abolished Ang IV formation. Similar to Ang II, Ang-(1–7) decreased the level of infection in an A779 (specific antagonist of Ang-(1–7) receptor, MAS)-sensitive manner. 10−7 M PD123319, an AT2 receptor antagonist, partially reversed the effects of Ang-(1–7) and Ang II. However, 10−6 M losartan, an antagonist of the AT1 receptor, had no effect. Gs protein is a crucial player in the Plasmodium falciparum blood cycle and angiotensin peptides can modulate protein kinase A (PKA) activity; 10−8 M Ang II or 10−8 M Ang-(1–7) inhibited this activity in erythrocytes by 60% and this effect was reversed by 10−7 M A779. 10−6 M dibutyryl-cAMP increased the level of infection and 10−7 M PKA inhibitor decreased the level of infection by 30%. These results indicate that the effect of Ang-(1–7) on P. falciparum blood stage involves a MAS-mediated PKA inhibition. Our results indicate a crucial role for Ang II conversion into Ang-(1–7) in controlling the erythrocytic cycle of the malaria parasite, adding new functions to peptides initially described to be involved in the regulation of vascular tonus
Impairment of the Plasmodium falciparum Erythrocytic Cycle Induced by Angiotensin Peptides
Plasmodium falciparum causes the most serious complications of malaria and is a public health problem worldwide with over 2 million deaths each year. The erythrocyte invasion mechanisms by Plasmodium sp. have been well described, however the physiological aspects involving host components in this process are still poorly understood. Here, we provide evidence for the role of renin-angiotensin system (RAS) components in reducing erythrocyte invasion by P. falciparum. Angiotensin II (Ang II) reduced erythrocyte invasion in an enriched schizont culture of P. falciparum in a dose-dependent manner. Using mass spectroscopy, we showed that Ang II was metabolized by erythrocytes to Ang IV and Ang-(1–7). Parasite infection decreased Ang-(1–7) and completely abolished Ang IV formation. Similar to Ang II, Ang-(1–7) decreased the level of infection in an A779 (specific antagonist of Ang-(1–7) receptor, MAS)-sensitive manner. 10−7 M PD123319, an AT2 receptor antagonist, partially reversed the effects of Ang-(1–7) and Ang II. However, 10−6 M losartan, an antagonist of the AT1 receptor, had no effect. Gs protein is a crucial player in the Plasmodium falciparum blood cycle and angiotensin peptides can modulate protein kinase A (PKA) activity; 10−8 M Ang II or 10−8 M Ang-(1–7) inhibited this activity in erythrocytes by 60% and this effect was reversed by 10−7 M A779. 10−6 M dibutyryl-cAMP increased the level of infection and 10−7 M PKA inhibitor decreased the level of infection by 30%. These results indicate that the effect of Ang-(1–7) on P. falciparum blood stage involves a MAS-mediated PKA inhibition. Our results indicate a crucial role for Ang II conversion into Ang-(1–7) in controlling the erythrocytic cycle of the malaria parasite, adding new functions to peptides initially described to be involved in the regulation of vascular tonus
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