Efficient ΦC31 integrase-mediated site-specific germline transformation of Anopheles gambiae.

Current transgenic methodology developed for mosquitoes has not been applied widely to the major malaria vector Anopheles gambiae, which has proved more difficult to genetically manipulate than other mosquito species and dipteran insects. In this protocol, we describe ΦC31-mediated site-specific integration of transgenes into the genome of A. gambiae.

Transgenic Anopheles gambiae expressing an antimalarial peptide suffer no significant fitness cost.

Mosquito-borne diseases present some of the greatest health challenges faced by the world today. In many cases, existing control measures are compromised by insecticide resistance, pathogen tolerance to drugs and the lack of effective vaccines. In light of these difficulties, new genetic tools for disease control programmes, based on the deployment of genetically modified mosquitoes, are seen as having great promise.

Killer bee molecules: antimicrobial peptides as effector molecules to target sporogonic stages of Plasmodium.

A new generation of strategies is evolving that aim to block malaria transmission by employing genetically modified vectors or mosquito pathogens or symbionts that express anti-parasite molecules. Whilst transgenic technologies have advanced rapidly, there is still a paucity of effector molecules with potent anti-malaria activity whose expression does not cause detrimental effects on mosquito fitness. Our objective was to examine a wide range of antimicrobial peptides (AMPs) for their toxic effects on Plasmodium and anopheline mosquitoes.

Contrasted Fitness Costs of Docking and Antibacterial Constructs in the EE and EVida3 Strains Validates Two-Phase Anopheles gambiae Genetic Transformation System.

The deployment of transgenic mosquitoes carrying genes for refractoriness to malaria has long been seen as a futuristic scenario riddled with technical difficulties. The integration of anti-malarial effector genes and a gene-drive system into the mosquito genome without affecting mosquito fitness is recognized as critical to the success of this malaria control strategy. Here we conducted detailed fitness studies of two Anopheles gambiae s.

Next-generation site-directed transgenesis in the malaria vector mosquito Anopheles gambiae: self-docking strains expressing germline-specific phiC31 integrase.

Diseases transmitted by mosquitoes have a devastating impact on global health and the situation is complicated due to difficulties with both existing control measures and the impact of climate change. Genetically modified mosquitoes that are refractory to disease transmission are seen as having great potential in the delivery of novel control strategies. The Streptomyces phage phiC31 integrase system has been successfully adapted for site-directed transgene integration in a range of insects, thus overcoming many limitations due to size constraints and random integration associated with transposon-mediated transformation.

A randomized trial of air cleaners and a health coach to improve indoor air quality for inner-city children with asthma and secondhand smoke exposure.

Objective: To test an air cleaner and health coach intervention to reduce secondhand smoke exposure compared with air cleaners alone or no air cleaners in reducing particulate matter (PM), air nicotine, and urine cotinine concentrations and increasing symptom-free days in children with asthma residing with a smoker.

Design: Randomized controlled trial, with randomization embedded in study database.

Settings: The Johns Hopkins Hospital Children's Center and homes of children.

Both the variability and level of mouse allergen exposure influence the phenotype of the immune response in workers at a mouse facility.

Background: The role of natural aeroallergen exposure in modulating allergen-specific immune responses is not well understood.

Objective: We sought to examine relationships between mouse allergen exposure and mouse-specific immune responses.

Methods: New employees (n = 179) at a mouse facility underwent repeated assessment of mouse allergen exposure, skin prick tests (SPTs), and measurement of mouse-specific IgG levels.

Site-specific integration and expression of an anti-malarial gene in transgenic Anopheles gambiae significantly reduces Plasmodium infections.

Diseases transmitted by mosquitoes have a devastating impact on global health and this is worsening due to difficulties with existing control measures and climate change. Genetically modified mosquitoes that are refractory to disease transmission are seen as having great potential in the delivery of novel control strategies. Historically the genetic modification of insects has relied upon transposable elements which have many limitations despite their successful use.

Occupational mouse allergen exposure among non-mouse handlers.

This study assessed mouse allergen exposure across a range of jobs, including non-mouse handling jobs, at a mouse facility. Baseline data from 220 new employees enrolled in the Jackson Laboratory (JAXCohort) were analyzed. The baseline assessment included a questionnaire, allergy skin testing, and spirometry.

Household smoking behavior: effects on indoor air quality and health of urban children with asthma.

The goal of the study was to examine the association between biomarkers and environmental measures of second hand smoke (SHS) with caregiver, i.e. parent or legal guardian, report of household smoking behavior and morbidity measures among children with asthma.

Childhood asthma and environmental exposures at swimming pools: state of the science and research recommendations.

Objectives: Recent studies have explored the potential for swimming pool disinfection by-products (DBPs), which are respiratory irritants, to cause asthma in young children. Here we describe the state of the science on methods for understanding children's exposure to DBPs and biologics at swimming pools and associations with new-onset childhood asthma and recommend a research agenda to improve our understanding of this issue.

Data Sources: A workshop was held in Leuven, Belgium, 21-23 August 2007, to evaluate the literature and to develop a research agenda to better understand children's exposures in the swimming pool environment and their potential associations with new-onset asthma.

Complex interactions of pollutant and allergen exposures and their impact on people with asthma.

Pediatric asthma has many causes and can manifest differently in different children and at different times. Understanding the many factors related to the development and exacerbation of asthma is complicated by the complexity of the many environmental exposures related to asthma development and morbidity. Furthermore, the same environmental exposures that may cause increased symptoms at 1 point in time may be protective when the exposure occurs earlier or at high enough levels.

Mediator release assay for assessment of biological potency of German cockroach allergen extracts.

Background: Cockroach is an important allergen in inner-city asthma. The diagnosis and treatment of cockroach allergy has been impeded by the lack of standardized cockroach extracts.

Objective: We investigated the utility of a mediator release assay based on rat basophil leukemia (RBL) cells for comparing the potency of German cockroach extracts.

In-home particle concentrations and childhood asthma morbidity.

Background: Although outdoor particulate matter (PM) has been linked to mortality and asthma morbidity, the impact of indoor PM on asthma has not been well established.

Objective: This study was designed to investigate the effect of in-home PM on asthma morbidity.

Methods: For a cohort of 150 asthmatic children (2-6 years of age) from Baltimore, Maryland, a technician deployed environmental monitoring equipment in the children's bedrooms for 3-day intervals at baseline and at 3 and 6 months.

Parent report of pests and pets and indoor allergen levels in inner-city homes.

Background: Guidelines recommend allergen avoidance for patients with allergic asthma, but direct measurements of home allergen levels are not available to most physicians. Parent report of indoor allergen exposure is a potentially convenient and inexpensive surrogate measure of exposure, although validity of parent report to estimate indoor allergen levels is not well established.

Objective: To determine if parent-reported pest and pet exposures can identify patients with clinically relevant allergen exposure.

Management of asthma based on exhaled nitric oxide in addition to guideline-based treatment for inner-city adolescents and young adults: a randomised controlled trial.

Background: Preliminary evidence is equivocal about the role of exhaled nitric oxide (NO) in clinical asthma management. We aimed to assess whether measurement of exhaled NO, as a biomarker of airway inflammation, could increase the effectiveness of asthma treatment, when used as an adjunct to clinical care based on asthma guidelines for inner-city adolescents and young adults.

Methods: We did a randomised, double-blind, parallel-group trial at ten centres in the USA.

Effects of dog ownership in early childhood on immune development and atopic diseases.

Background: Exposure to pets in childhood has been associated with a reduced risk of wheezing and atopy.

Objective: Our objective was to determine whether the effects of pet exposure on immune development and atopy in early childhood can be explained by alterations in exposure to innate immune stimuli in settled dust.

Methods: Two hundred and seventy-five children at increased risk of developing allergic diseases were evaluated to age 3 years for pet ownership, blood cell cytokine responses, and atopy.

Does neighborhood violence lead to depression among caregivers of children with asthma?

Prior studies have related community violence to depression among children, but few studies have examined this relationship among adults. We hypothesized that victimization, awareness, and fear of neighborhood violence would increase the odds of depression among adult caregivers of children with asthma. We surveyed caregivers in the Baltimore Indoor Environment Study of Asthma in Kids (BIESAK), USA.

The malaria vector mosquito Anopheles gambiae expresses a suite of larval-specific defensin genes.

cDNAs of Anopheles gambiae Defensin 2 (AgDef2), Defensin 3 (AgDef3) and Defensin 4 (AgDef4), identified in the genome sequence, have been characterized and their expression profiles investigated. In contrast to both typical defensins and insect antimicrobial peptides generally, the newly identified defensins were not upregulated with acute-phase kinetics following immune challenge in insects or cell culture. However, mRNA abundance of AgDef2, AgDef3 and AgDef4 increased significantly during the larval stages.

The environment and asthma in US inner cities.

Poor, minority children living in US inner cities have increased rates of asthma morbidity and mortality. Factors that contribute to these increased rates are varied and complex, with current evidence suggesting that the environment is an important causative factor. Respiratory morbidity is often the result of allergens and air pollutants.