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Histochemical and ultrastructural studies of the mosquito Aedes aegypti fat body: effects of aging and diet type.

Aedes aegypti is the principal vector of dengue world wide and a major vector of urban yellow fever. Despite its epidemiological importance, not much is known regarding cellular and structural changes in the fat body in this mosquito. Here, we applied light and transmission electron microscopies to investigate structural changes in the fat body of three groups of A. aegypti females: newly emerged, 18-day-old sugar-fed, and 18-day-old blood-fed. The fat body consists of a layer of cells attached to the abdomen integument, formed by trophocytes and oenocytes. Trophocytes are strongly positive fo…

Vaccination of patients with diabetes mellitus--a retrospective study.

402 subjects with diabetes mellitus have been vaccinated of the total of 34,000 vaccinees immunized during the study period of 9 and half mo … ve been given to 6 patients with diabetes (1.49%)--- 5 travellers to endemic countries received the yellow fever vaccine Stamaril (1 female, 4 male) and one male patient varicella vaccine Varilrix. Among the least common vaccines in diabetic patients were those against invasive pneumococcal and meningococcal infections. Not a single unexpected side effect has …

[Clinical manifestation and EEG characteristics of Angelman syndrome].

OBJECTIVE: To investigate the clinical manifestations and EEG characteristics of Angelman syndrome in children, and to strengthen the recognition of this disease. METHOD: Fourteen children with Angelman syndrome received video EEG monitoring, head MRI/CT and gene test, 11 patients received the metabolic investigations (e.g., lactic acid, ammonia, GC/MS and MS/MS). Eight patients received Gesell test. The patients were followed up for 1-3 years. RESULT: Of the 14 cases, 4 were male and 10 female, their age was from 8 months to 3 years and 7 months. The clinical characteristics included promin

Recent progress on sanofi pasteur's dengue vaccine candidate.

The sanofi pasteur candidate dengue tetravalent vaccine (TV) is a recombinant live attenuated vaccine. It is based on a backbone of yellow fever vaccine (YF 17D) replication genes and incorporates the envelope genes of the four dengue virus serotypes. Pre-clinical studies have demonstrated that dengue TV is genetically stable, non-hepatotropic, less neurovirulent than YF 17D and does not infect mosquitoes by the oral route. Dengue TV reactogenicity, viraemia induction and antibody responses were investigated in three Phase II trials in the USA, the Philippines and Mexico. Participants were ran…

Macaque models of human infectious disease.

Macaques have served as models for more than 70 human infectious diseases of diverse etiologies, including a multitude of agents-bacteria, viruses, fungi, parasites, prions. The remarkable diversity of human infectious diseases that have been modeled in the macaque includes global, childhood, and tropical diseases as well as newly emergent, sexually transmitted, oncogenic, degenerative neurologic, potential bioterrorism, and miscellaneous other diseases. Historically, macaques played a major role in establishing the etiology of yellow fever, polio, and prion diseases. With rare exceptions (Cha…

Mosquito larval habitats and public health implications in Abeokuta, Ogun State, Nigeria.

The larval habitats of mosquitoes were investigated in Abeokuta, Nigeria in order to determine the breeding sites of the existing mosquito f … he habitats to support the breeding of Aedes, Culex and Anopheles, which are known vectors of urban yellow fever, lymphatic filariasis and malaria suggest that the residents ofAbeokuta City are at risk of mosquito-borne diseases. It is important that residents of the City are enlighten on the environmental factors that contribute to mosquito breeding and that …

Synthesis and biological evaluation of benzo[d]isothiazole, benzothiazole and thiazole Schiff bases.

Three new series of benzo[d]isothiazole, benzothiazole and thiazole Schiff bases were synthesized and tested in vitro with the aim of identi … classes, such as a HIV-1 (Retrovirus), a HBV (Hepadnavirus) and the single-stranded RNA(+) viruses Yellow fever virus (YFV) and Bovine viral diarrhoea virus (BVDV), both belonging to Flaviviridae. Title compounds were also tested against representatives of Gram-positive and Gram-negative bacteria (Staphylococcus aureus, Salmonella spp.), various atypic mycoba …

Limited potential for transmission of live dengue virus vaccine candidates by Aedes aegypti and Aedes albopictus.

To evaluate the transmission risk of four live dengue (DEN) vaccine candidates developed by the U.S. Army (DEN-1, 45AZ5 PDK 20; DEN-2, S16803 PDK 50; DEN-3, CH53489 PDK 20; and DEN-4, 341750 PDK 20), we tested 3,010 Aedes aegypti and 1,576 Aedes albopictus mosquitoes blood-fed on 21 volunteers who had been administered one of the four vaccine candidates or the licensed yellow fever (YF) vaccine (17D). We used an indirect immunofluorescence assay (IFA) to detect DEN or YF viral antigen in the heads of mosquitoes. Corresponding to the lack of a detectable viremia among volunteers inoculated 8-13…

The concentration-dependence of CRF-like diuretic peptide: mechanisms of action.

The mechanism of action of synthetic CCRF-DP, the corticotropin-releasing factor (CRF)-related diuretic peptide of the salt marsh mosquito Culex salinarius, was investigated in isolated Malpighian tubules of the yellow fever mosquito Aedes aegypti. A low concentration of CCRF-DP (10(-9)mol l-1) caused a small but insignificant increase in transepithelial secretion of NaCl and fluid, but significantly reduced transepithelial voltage and resistance without a change in short-circuit current, pointing to the stimulation of passive Cl- transport through the paracellular pathway as the principal mec…

Identification of Brazilian flaviviruses by a simplified reverse transcription-polymerase chain reaction method using Flavivirus universal primers.

We report a simplified reverse transcription-polymerase chain reaction (RT-PCR) method for identification of Brazilian flaviviruses based on … results and three distinct amplicon patterns were observed. Cacipacoré (800-850 basepairs [bp]) and yellow fever viruses (600 bp) yielded a single amplicon; dengue virus types 1 and 2 (650 and 550 bp), dengue virus type 4 (550 and 450 bp), Iguape (650-600 bp and 750-700 bp), St. Louis encephalitis (700 and 650-600 bp), and Rocio viruses (600 and 500-550 bp) yi …

Diversity of Gut Bacteria of Field-Collected Aedes aegypti Larvae and Females, Resistant to Temephos and Deltamethrin.

The Aedes aegypti mosquito serves as a vector for several diseases, including dengue, Zika, chikungunya, and yellow fever. This species is well adapted to urban environments and poses a significant threat to public health. Some studies suggest that the gut bacteria of insect vectors may play a crucial role in developing resistance to insecticides. This study assessed the resistance of Ae. aegypti from Florencia, Caquetá, to temephos and deltamethrin and analyzed the diversity of gut bacteria in resistant larvae and adult females. Larvae exhibited resistance to temephos at a lethal concentratio…

Evolution and adaptation of dengue virus in response to high-temperature passaging in mosquito cells.

The incidence of arboviral diseases like dengue, chikungunya, and yellow fever continues to rise in association with the expanding geographic ranges of their vectors, Aedes aegypti and Aedes albopictus. The distribution of these vectors is believed to be driven in part by climate change and increasing urbanization. Arboviruses navigate a wide range of temperatures as they transition from ectothermic vectors (from 15°C to 35°C) to humans (37°C) and back again, but the role that temperature plays in driving the evolution of arboviruses remains largely unknown. Here, we passaged replicate dengue …

Epidemiological situation of hepatitis E in Africa.

Hepatitis E virus (HEV) belongs to the Hepeviridae family, Orthohepevirinae subfamily, Paslahepevirus genus which includes eight genotypes. … incriminated in symptoms without etiology or falsely attributed to other hepatic viruses or to the yellow fever virus. This review updates studies on the epidemiology of HEV in Africa, a crucial step to better understand the virus and develop surveillance strategies to prevent and better control epidemics.

Transposable elements in the transcriptome of Aedes (Stegomyia) aegypti (Linnaeus, 1762).

The Aedes (Stegomyia) aegypti mosquito is the main vector of arboviruses such as dengue, urban yellow fever, chikungunya and Zika. The extensive use of insecticides to control this vector has led to the selection of resistant populations, compromising the effectiveness of control programmes. Insecticide resistance is often related to the integration of transposable elements (TEs) in specific genes. TEs can also contribute to the regulation of gene expression in response to insecticides. In this paper, we performed transcriptome analysis of the mosquito Ae. aegypti using bioinformatics tools to…

Inferring Geographic Spread of Flaviviruses Through Analysis of Hypervariable Genomic Regions.

The Flaviviruses Dengue virus (DENV), West Nile virus (WNV), Zika virus (ZIKV), and Yellow Fever virus (YFV), are mosquito-borne viruses that represent a persistent challenge to global health due to the emergence and re-emergence of outbreaks of significant magnitudes. Their positive-sense RNA genome, about 11,000 nucleotides long, encodes structural and nonstructural proteins. These viruses evolve rapidly through mutations and genetic recombination, which can lead to more virulent and transmissible strains. Although whole-genome sequencing is ideal for studying their evolution and geographic …

Potential effects of brown howler monkey extinction on dispersal services in fragmented forests void of large dispersers.

The dispersal of large-seeded species strongly depends on medium-sized and large frugivores, such as primates, which are highly susceptible to population declines. In the Atlantic Forest, brown howler monkeys Alouatta guariba are medium-sized folivorous-frugivorous species that are likely to occur in small to large fragments where the largest frugivores are extinct. However, populations of this primate have been suffering from forest fragmentation, habitat loss, hunting, and the direct and indirect effects of yellow fever outbreaks, which increase the importance of understanding their role as …

First report of V1016I, F1534C and V410L kdr mutations associated with pyrethroid resistance in Aedes aegypti populations from Niamey, Niger.

BACKGROUND: Ae. aegypti is the vector of important μ arboviruses, including dengue, Zika, chikungunya and yellow fever. Despite not being specifically targeted by insecticide-based control programs in West Africa, resistance to insecticides in Ae. aegypti has been reported in countries within this region. In this study, we investigated the status and mechanisms of Ae. aegypti resistance in Niamey, the capital of Niger. This research aims to provide baseline data necessary for arbovirus outbreak prevention and preparedness in the country. METHODS: Ovitraps were used to collect Ae. aegypti eggs…

То, как борьба с насекомыми-вредителями регулируется зависимостью плотности населения: перспектива генетического биоконтроля.

Регулирование видов вредителей в решающей степени зависит от механизмов, регулирующих динамику населения, особенно от тех факторов, которые меняются в зависимости от численности населения. Эти факторы, зависящие от плотности, могут способствовать или препятствовать усилиям по контролю и особенно актуальны с учетом последних достижений в области генетических методов, позволяющих точно манипулировать сроками и спецификой контроля по признаку пола. Несмотря на это важное значение, зависимость от плотности населения зачастую является слабой из-за ограниченности данных и неполного понимания экологи

Совпадение в аннотации оригинала
Managing pest species relies critically on mechanisms that regulate population dynamics, particularly those factors that change with populat … rength of density dependence. While the model is parameterized using the life history traits of the yellow fever mosquito, Aedes aegypti, the principles developed here apply to many pest species. We conclude by discussing what this means for pest population suppression moving forward.

Conflict and fragmented public health emergency management system in Tigray region of Northern Ethiopia: A double burden to accommodate resilient and advanced public health emergency management. A commentary review for policy-makers and a call to action.

An estimated 2.5 million people have been internally and externally displaced in the Tigray region of northern Ethiopia in conflict and post … th, for instance, zoonotic diseases (anthrax and rabies), acute watery diarrhoea, measles, malaria, yellow fever, and coronavirus disease 2019 (COVID-19) approaching to their level of epidemic. Moreover, they will spike as an epidemic in the future. All these circumstances made it evident that the system need reform to adhere with legal global, national, and r …

Characterizing Physical Interactions between Male and Female Mosquitoes (Aedes aegypti) in Relation to Female Receptivity and Insemination Outcomes Using a Hydrophobic Fluorescent Dye.

Aedes aegypti, the yellow fever mosquito, presents a major threat to human health across the globe as a vector of disease-causing pathogens. Females of this species generally mate only once. From this single mating event, the female stores sufficient sperm to fertilize the multiple clutches of eggs produced during her lifetime. Mating causes dramatic changes in the female's behavior and physiology, including a lifetime suppression of her mating receptivity. Female rejection behaviors include male avoidance, abdominal twisting, wing-flicking, kicking, and not opening vaginal plates or extruding…