Stinging insect hypersensitivity: a practice parameter update 2011.

These parameters were developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma and Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Stinging insect hypersensitivity: a practice parameter update II." Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or the ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma and Immunology. This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. These parameters are not designed for use by pharmaceutical companies in drug promotion. The Joint Task Force understands that the cost of diagnostic tests and therapeutic agents is an important concern that may appropriately influence the work-up and treatment chosen for a given patient. The Joint Task Force recognizes that the emphasis of our primary recommendations regarding a medication may vary, for example, depending on third party payer issues and product patent expiration dates. However, since a given test or agent's cost is so widely variable, and there is a paucity of pharmacoeconomic data, the Joint Task Force generally does not consider cost when formulating Practice Parameter recommendations. In extraordinary circumstances, when the cost benefit of an intervention is prohibitive as supported by pharmacoeconomic data, commentary may be provided.

Sublingual Immunotherapy for Other Indications: Venom Large Local, Latex, Atopic Dermatitis, and Food.

There is some evidence to support the use of sublingual immunotherapy (SLIT) in food allergy, although its role is unclear. One randomized, double-blind, placebo-controlled trial supports the safe and efficacious use of dust mite SLIT in children with mild to moderate atopic dermatitis, but these data have not been confirmed. Although there are several randomized, double-blind, placebo-controlled trials to support the use of SLIT-LATEX, this product is not available in the United States and extrapolation of these effects to latex extracts is unsubstantiated. There is also insufficient evidence to support the use of SLIT for venom hypersensitivity at this time.

ß-Blockers and angiotensin-converting enzyme inhibitors with sublingual immunotherapy: are risks related to individual product safety profile?

PURPOSE OF REVIEW: The objective of this article is to review the available literature regarding the risks associated with sublingual immunotherapy and angiotensin-converting enzyme (ACE) inhibitors or ß-blocker use. It also evaluates for any differences in these risks among the available sublingual immunotherapy (SLIT) tablets. RECENT FINDINGS: A literature search was conducted in PubMed to identify peer-reviewed articles using the following keywords: anaphylaxis, ACE inhibitor, ß-blocker, and sublingual immunotherapy. Minimal data exist regarding their safety of SLIT in patients concomitantly taking ACE inhibitors or ß-blockers. The adverse reaction rates seem similar between SLIT products. SUMMARY: A risk-versus-benefit discussion should be communicated with the patient taking a ß-blocker before beginning SLIT but automatic denial of SLIT to these patients is not warranted.

Analysis of the genome of the Escherichia coli O157:H7 2006 spinach-associated outbreak isolate indicates candidate genes that may enhance virulence.

In addition to causing diarrhea, Escherichia coli O157:H7 infection can lead to hemolytic-uremic syndrome (HUS), a severe disease characterized by hemolysis and renal failure. Differences in HUS frequency among E. coli O157:H7 outbreaks have been noted, but our understanding of bacterial factors that promote HUS is incomplete. In 2006, in an outbreak of E. coli O157:H7 caused by consumption of contaminated spinach, there was a notably high frequency of HUS. We sequenced the genome of the strain responsible (TW14359) with the goal of identifying candidate genetic factors that contribute to an enhanced ability to cause HUS. The TW14359 genome contains 70 kb of DNA segments not present in either of the two reference O157:H7 genomes. We identified seven putative virulence determinants, including two putative type III secretion system effector proteins, candidate genes that could result in increased pathogenicity or, alternatively, adaptation to plants, and an intact anaerobic nitric oxide reductase gene, norV. We surveyed 100 O157:H7 isolates for the presence of these putative virulence determinants. A norV deletion was found in over one-half of the strains surveyed and correlated strikingly with the absence of stx(1). The other putative virulence factors were found in 8 to 35% of the O157:H7 isolates surveyed, and their presence also correlated with the presence of norV and the absence of stx(1), indicating that the presence of norV may serve as a marker of a greater propensity for HUS, similar to the correlation between the absence of stx(1) and a propensity for HUS.

Characterization of protein cross-links via mass spectrometry and an open-modification search strategy.

Protein-protein interactions are key to function and regulation of many biological pathways. To facilitate characterization of protein-protein interactions using mass spectrometry, a new data acquisition/analysis pipeline was designed. The goal for this pipeline was to provide a generic strategy for identifying cross-linked peptides from single LC/MS/MS data sets, without using specialized cross-linkers or custom-written software. To achieve this, each peptide in the pair of cross-linked peptides was considered to be "post-translationally" modified with an unknown mass at an unknown amino acid. This allowed use of an open-modification search engine, Popitam, to interpret the tandem mass spectra of cross-linked peptides. False positives were reduced and database selectivity increased by acquiring precursors and fragments at high mass accuracy. Additionally, a high-charge-state-driven data acquisition scheme was utilized to enrich data sets for cross-linked peptides. This open-modification search based pipeline was shown to be useful for characterizing both chemical as well as native cross-links in proteins. The pipeline was validated by characterizing the known interactions in the chemically cross-linked CYP2E1-b5 complex. Utility of this method in identifying native cross-links was demonstrated by mapping disulfide bridges in RcsF, an outer membrane lipoprotein involved in Rcs phosphorelay.

Are ACE Inhibitors and Beta-blockers Dangerous in Patients at Risk for Anaphylaxis?

The objective of this article is to review the available studies regarding angiotensin converting enzyme (ACE) inhibitors and beta-blockers and their effect on patients at risk for anaphylaxis. A literature search was conducted in PUBMED to identify peer-reviewed articles using the following keywords: anaphylaxis, ACE inhibitor, beta-blocker, food allergy, radiocontrast media, venom allergy, skin testing, and immunotherapy. Some studies show an increased risk of anaphylaxis in patients who are taking ACE inhibitors and beta-blockers, whereas others studies do not show an increased risk. For venom immunotherapy, there are more data supporting the concomitant use of beta-blockers and ACE inhibitors in the build-up and maintenance phases. Most of the medical literature is limited to case reports and retrospective data. Prospective controlled trials are needed on this important topic. For those patients at risk of anaphylaxis who lack cardiovascular disease, it is recommended to avoid beta-blockers and possibly ACE inhibitors. However, for those patients with cardiovascular disease, beta-blockers and ACE inhibitors have been shown to increase life expectancy. Consideration should be given for the concomitant use of these medications while patients are receiving venom immunotherapy.

ABAI's MOC Assessment of Knowledge Program Matures: Adding Value with Continuous Learning and Assessment.

Rapid changes in modern medicine along with advances in the science of learning and memory have necessitated a shift in the way physician knowledge is assessed. Physician recertification beyond initial certification has historically consisted of retaining large amounts of knowledge over a long time span. The adult learning theory has shown that the maintenance and improvement of our knowledge base is more effective by being exposed to new concepts at regular intervals throughout one's career and reinforcing these concepts on an ongoing basis. These philosophies have spurred several American Board of Medical Specialties member boards to embark on a variety of continuous assessment models that are designed to keep physicians up to date with the use of new technologies and innovative and flexible question formats. This article describes the new American Board of Allergy and Immunology (ABAI) Continuous Assessment Program. As the ABAI departs from the traditional secure examination/test center model and embarks on its new pilot, the focus remains firmly rooted in the core competencies that patients and the public demand and deserve. Through surveys, the ABAI has laid the groundwork for initial program design by asking its diplomates to rank the most relevant aspects of a sound clinical assessment. Periodic surveys to follow will enable the ABAI to adjust program design to provide the most pertinent content to practicing physicians to improve patient care, promote professionalism, and ensure public trust.

Deciphering diatom biochemical pathways via whole-cell proteomics.

Diatoms play a critical role in the oceans' carbon and silicon cycles; however, a mechanistic understanding of the biochemical processes that contribute to their ecological success remains elusive. Completion of the Thalassiosira pseudonana genome provided 'blueprints' for the potential biochemical machinery of diatoms, but offers only a limited insight into their biology under various environmental conditions. Using high-throughput shotgun proteomics, we identified a total of 1928 proteins expressed by T. pseudonana cultured under optimal growth conditions, enabling us to analyze this diatom's primary metabolic and biosynthetic pathways. Of the proteins identified, 70% are involved in cellular metabolism, while 11% are involved in the transport of molecules. We identified all of the enzymes involved in the urea cycle, thereby describing the complete pathway to convert ammonia to urea, along with urea transporters, and the urea-degrading enzyme urease. Although metabolic exchange between these pathways remains ambiguous, their constitutive presence suggests complex intracellular nitrogen recycling. In addition, all C(4) related enzymes for carbon fixation have been identified to be in abundance, with high protein sequence coverage. Quantification of mass spectra acquisitions demonstrated that the 20 most abundant proteins included an unexpectedly high expression of clathrin, which is the primary structural protein involved in endocytic transport. This result highlights a previously overlooked mechanism for the inter- and intra-cellular transport of nutrients and macromolecules in diatoms, potentially providing a missing link to organelle communication and metabolite exchange. Our results demonstrate the power of proteomics, and lay the groundwork for future comparative proteomic studies and directed analyses of specifically expressed proteins and biochemical pathways of oceanic diatoms.

Growth phenotypes of Pseudomonas aeruginosa lasR mutants adapted to the airways of cystic fibrosis patients.

The opportunistic pathogen Pseudomonas aeruginosa undergoes genetic change during chronic airway infection of cystic fibrosis (CF) patients. One common change is a mutation inactivating lasR, which encodes a transcriptional regulator that responds to a homoserine lactone signal to activate expression of acute virulence factors. Colonies of lasR mutants visibly accumulated the iridescent intercellular signal 4-hydroxy-2-heptylquinoline. Using this colony phenotype, we identified P. aeruginosa lasR mutants that emerged in the airway of a CF patient early during chronic infection, and during growth in the laboratory on a rich medium. The lasR loss-of-function mutations in these strains conferred a growth advantage with particular carbon and nitrogen sources, including amino acids, in part due to increased expression of the catabolic pathway regulator CbrB. This growth phenotype could contribute to selection of lasR mutants both on rich medium and within the CF airway, supporting a key role for bacterial metabolic adaptation during chronic infection. Inactivation of lasR also resulted in increased beta-lactamase activity that increased tolerance to ceftazidime, a widely used beta-lactam antibiotic. Loss of LasR function may represent a marker of an early stage in chronic infection of the CF airway with clinical implications for antibiotic resistance and disease progression.

Comparison of Francisella tularensis genomes reveals evolutionary events associated with the emergence of human pathogenic strains.

BACKGROUND: Francisella tularensis subspecies tularensis and holarctica are pathogenic to humans, whereas the two other subspecies, novicida and mediasiatica, rarely cause disease. To uncover the factors that allow subspecies tularensis and holarctica to be pathogenic to humans, we compared their genome sequences with the genome sequence of Francisella tularensis subspecies novicida U112, which is nonpathogenic to humans. RESULTS: Comparison of the genomes of human pathogenic Francisella strains with the genome of U112 identifies genes specific to the human pathogenic strains and reveals pseudogenes that previously were unidentified. In addition, this analysis provides a coarse chronology of the evolutionary events that took place during the emergence of the human pathogenic strains. Genomic rearrangements at the level of insertion sequences (IS elements), point mutations, and small indels took place in the human pathogenic strains during and after differentiation from the nonpathogenic strain, resulting in gene inactivation. CONCLUSION: The chronology of events suggests a substantial role for genetic drift in the formation of pseudogenes in Francisella genomes. Mutations that occurred early in the evolution, however, might have been fixed in the population either because of evolutionary bottlenecks or because they were pathoadaptive (beneficial in the context of infection). Because the structure of Francisella genomes is similar to that of the genomes of other emerging or highly pathogenic bacteria, this evolutionary scenario may be shared by pathogens from other species.