Exploring the relationship between falls, fall-related psychological concerns, and personality traits in adults: A scoping review protocol

Background and Aims

Personality traits, such as neuroticism and extraversion, are emerging as important predictors of falls. Despite their significance, existing fall prevention programs often overlook these traits, creating a notable research gap. This study aims to conduct a comprehensive scoping review to explore the existing literature on the relationships among personality traits, falls, and fall-related psychological concerns (FrPCs).

Methods

This scoping review will adhere to the framework established by Arksey and O'Malley, incorporating extensions recommended by the Joanna Briggs Institute and using the PRISMA-ScR checklist. A thorough search strategy will be employed, aligning with the population, concept, and context (PCC) selection criteria. Electronic databases, including MEDLINE, APA PsycINFO, Web of Science, CINAHL, and SPORTDiscus, will be searched from their inception to the present. Additionally, a manual search of the reference lists of identified and relevant full-text articles will be conducted. Two independent reviewers will screen titles and abstracts, perform full-text reviews, and extract data from pertinent articles.

Discussion

Personality traits are increasingly recognized as influential predictors of falls and related psychological concerns. This review aims to make a substantial contribution to the existing literature by being the first to comprehensively explore and provide a descriptive synthesis of the relationship between personality traits and falls, as well as FrPCs in adults. It is hoped that the outcomes of this review will enhance our comprehension of the role of personality traits in falls, potentially informing future research and strategies for this critical area of study.

Scoping Review Registration

This scoping review protocol was registered with Open Science Framework (https://doi.org/10.17605/OSF.IO/KR74X).

A luminous fast radio burst that probes the Universe at redshift 1

Fast radio bursts (FRBs) are millisecond-duration pulses of radio emission originating from extragalactic distances. Radio dispersion is imparted on each burst by intervening plasma, mostly located in the intergalactic medium. In this work, we observe the burst FRB 20220610A and localize it to a morphologically complex host galaxy system at redshift 1.016 ± 0.002. The burst redshift and dispersion measure are consistent with passage through a substantial column of plasma in the intergalactic medium and extend the relationship between those quantities measured at lower redshift. The burst shows evidence for passage through additional turbulent magnetized plasma, potentially associated with the host galaxy. We use the burst energy of 2 × 1042 erg to revise the empirical maximum energy of an FRB.

Association between sociodemographic factors and mobility limitation among older adults: a systematic review and meta-analysis protocol

BACKGROUND

Mobility is an independent predictor of physical functionality, healthy ageing, and quality of life. Various literatures have associated mobility limitation in older adulthood with demographic and socioeconomic factors. Hence, we propose a systematic review and meta-analysis to synthesise the association between sociodemographic factors and mobility limitations in older adults.

METHODS AND ANALYSES

This protocol was written according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines. We will perform a comprehensive search of all observational studies that assessed the relationship between age, gender, race, place, education, income, occupation, social status, and walking distance, time, or speed. Electronic databases (MEDLINE, Web of Science, EMBASE, CINAHL, AgeLine, and SPORTDiscus) will be searched from inception to 28 February 2023. We will supplement the database search by manually searching the reference lists of all identified and relevant full-text articles. Two independent reviewers will be responsible for screening articles, data extraction, and assessment of bias. We will appraise the study quality and risk of bias using the Prediction Model Risk of Bias Assessment Tool (PROBAST). A meta-analysis will be considered if data from the selected studies are homogeneous, otherwise, a narrative synthesis of the extracted data will be presented.

DISCUSSION

Mobility limitation leads to frequent falls, dependency, morbidity, and death among older adults. This review is necessary, to identify and prioritise important sociodemographic factors during older adults' clinical assessment and policy development. It is the first phase of a multi-methods study seeking to develop a prognostic mobility trajectory for community-dwelling older adults.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022298570.

Determinants of Outdoor Time in Children and Youth: A Systematic Review of Longitudinal and Intervention Studies

Spending more time outdoors can improve children's social and cognitive development, physical activity, and vision. Our systematic review summarized the determinants of outdoor time (OT) based on the social-ecological model. We searched nine databases: MEDLINE, APA PsycINFO, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, SPORTDiscus, ERIC, SocINDEX, and ProQuest Dissertations and Theses. To be included, studies needed to be quantitative and longitudinal, include ≥1 potential determinant of OT among 0- to 17-year-olds, and be published in English, French, Japanese, or Spanish. We extracted the authors, publication year, country, design, sample size, OT measures, follow-up period, potential determinants, main results, and potential moderators or mediators. Fifty-five studies examining 119 potential determinants met the inclusion criteria. OT was consistently higher in warmer seasons and among participants reporting more OT at baseline. All three interventions that included both parent sessions and additional resources to promote OT (e.g., specific advice and community guides) were effective. COVID-19 restrictions and sun safety interventions discouraging midday outdoor activities led to less OT. The quality of evidence was rated as weak for 46 studies. Most potential determinants were examined in ≤3 studies; thus, more longitudinal studies are needed to enable stronger conclusions about the consistency of evidence and meta-analyses.

Data-sharing practices in publications funded by the Canadian Institutes of Health Research: a descriptive analysis

BACKGROUND

As Canada increases requirements for research data management and sharing, there is value in identifying how research data are shared and what has been done to make them findable and reusable. This study aimed to understand Canada's data-sharing landscape by reviewing how data funded by the Canadian Institutes of Health Research (CIHR) are shared and comparing researchers' data-sharing practices to best practices for research data management and sharing.

METHODS

We performed a descriptive analysis of CIHR-funded publications from PubMed and PubMed Central published between 1946 and Dec. 31, 2019, that indicated that the research data underlying the results of the publication were shared. We analyzed each publication to identify how and where data were shared, who shared data and what documentation was included to support data reuse.

RESULTS

Of 4144 CIHR-funded publications identified, 1876 (45.2%) included accessible data, 935 (22.6%) stated that data were available via request or application, and 300 (7.2%) stated that data sharing was not applicable or possible; we found no evidence of data sharing in 1558 publications (37.6%). Frequent data-sharing methods included via a repository (1549 [37.4%]), within supplementary files (1048 [25.3%]) and via request or application (935 [22.6%]). Overall, 554 publications (13.4%) included documentation that would facilitate data reuse.

INTERPRETATION

Publications funded by the CIHR largely lack the metadata, access instructions and documentation to facilitate data discovery and reuse. Without measures to address these concerns and enhanced support for researchers seeking to implement best practices for research data management and sharing, much CIHR-funded research data will remain hidden, inaccessible and unusable.

Celiac disease gene expression data can be used to classify biopsies along the Marsh score severity scale

BACKGROUND AND AIM

The diagnosis of celiac disease autoimmune pathology relies on the subjective histological assignment of biopsies into Marsh score categories. It is hypothesized that Marsh score categories have unique gene expression signatures. The aims were as follows: first, to develop a celiac disease quantitative reverse transcription-polymerase chain reaction (RT-PCR) array; second, define gene expression signatures associated with Marsh score categories; and third, develop equations that classify biopsies into Marsh score categories and to monitor the efficacy of patient treatment.

METHODS

Gene targets for inclusion in the celiac RT-PCR (qRT-PCR) array were identified using systematic analysis of published celiac transcriptomic data. The array was used to assess the gene expression associated with histological changes in duodenal biopsies obtained from adult patients. Finally, Marsh score classification equations were defined using discriminant analysis.

RESULTS

The array contained 87 genes. The expression of 26 genes were significantly (p < 0.06) associated with the discrete Marsh score categories. As the Marsh score pathology of biopsies increased, there was a progression of innate immune gene expression through adaptive Th1-specific gene expression with a concurrent decrease in intestinal structural gene expression in high Marsh score samples. These 26 genes were used to define classification equations that accounted for 99% of the observed experimental variation and which could classify biopsies into Marsh score categories and monitor patient treatment progression.

CONCLUSIONS

This proof-of-concept study successfully developed a celiac RT-PCR array and has provided evidence that discriminant equations defined using gene expression data can objectively and accurately classify duodenal biopsies into Marsh score categories.

Equations defined using gene expression and histological data resolve coeliac disease biopsies within the Marsh score continuum

BACKGROUND/AIM

The gold standard diagnostic for coeliac disease (CD) is subjective histological assignment of biopsies into the Marsh score categories. It is hypothesized that discrete Marsh score categories can be quantitatively resolved into a continuum using discriminant equations defined using histological and gene expression data. Therefore, the aim of this study was to use a combination of histological and gene expression data to develop equations that classify CD patient biopsies into a quantitative Marsh score continuum which could be used by clinicians to monitor CD treatment efficacy.

METHODS

Both empirical and simulated gene expression and histological data were used to define predictive Marsh score equations. The distances of treated sample biopsies from the Marsh score standards were determined using the Mahalanobis distance calculation.

RESULTS

Three function, high resolution discriminant equations derived from simulated data were used to accurately classify 99.6% of simulated and empirically derived biopsy data. The first function resolved active (Marsh type 3) CD from mild (Marsh type 1) CD. The second function resolved normal (no specific pathology) biopsies from mild CD. The third function resolved active Marsh score 3 into a and b subcategories. Finally, measuring the Mahalanobis distance enabled the conversion of discrete Marsh score categories into a continuum.

CONCLUSIONS

This proof-of-concept study successfully demonstrated that the discrete Marsh score scale can be converted into a quantitative continuum capable of high resolution monitoring of patient treatment efficacy using equations defined by gene expression and histology data.

Acid-regulated gene expression of Helicobacter pylori: Insight into acid protection and gastric colonization

BACKGROUND

The pathogen Helicobacter pylori encounters many stressors as it transits to and infects the gastric epithelium. Gastric acidity is the predominate stressor encountered by the bacterium during initial infection and establishment of persistent infection. H. pylori initiates a rapid response to acid to maintain intracellular pH and proton motive force appropriate for a neutralophile. However, acid sensing by H. pylori may also serve as a transcriptional trigger to increase the levels of other pathogenic factors needed to subvert host defenses such as acid acclimation, antioxidants, flagellar synthesis and assembly, and CagA secretion.

MATERIALS AND METHODS

Helicobacter pylori were acid challenged at pH 3.0, 4.5, 6.0 vs nonacidic pH for 4 hours in the presence of urea, followed by RNA-seq analysis and qPCR. Cytoplasmic pH was monitored under the same conditions.

RESULTS

About 250 genes were induced, and an equal number were repressed at acidic pHs. Genes encoding for antioxidant proteins, flagellar structural proteins, particularly class 2 genes, T4SS/Cag-PAI, F_o F₁ -ATPase, and proteins involved in acid acclimation were highly expressed at acidic pH. Cytoplasmic pH decreased from 7.8 at pH_out of 8.0 to 6.0 at pH_out of 3.0.

CONCLUSIONS

These results suggest that increasing extracellular or intracellular acidity or both are detected by the bacterium and serve as a signal to initiate increased production of protective and pathogenic factors needed to counter host defenses for persistent infection. These changes are dependent on degree of acidity and time of acid exposure, triggering a coordinated response to the environment required for colonization.

Nonpharmacological Management of Behavioral and Psychological Symptoms of Dementia: What Works, in What Circumstances, and Why?

Objective

Behavioral and psychological symptoms of dementia (BPSD) refer to the often distressing, noncognitive symptoms of dementia. BPSD appear in up to 90% of persons with dementia and can cause serious complications. Reducing the use of antipsychotic medications to treat BPSD is an international priority. This review addresses the following questions: What nonpharmacological interventions work to manage BPSD? And, in what circumstances do they work and why?

Method

A realist review was conducted to identify and explain the interactions among context, mechanism, and outcome. We searched electronic databases for empirical studies that reported a formal evaluation of nonpharmacological interventions to decrease BPSD.

Results

Seventy-four articles met the inclusion criteria. Three mechanisms emerged as necessary for sustained effective outcomes: the caring environment, care skill development and maintenance, and individualization of care. We offer hypotheses about how different contexts account for the success, failure, or partial success of these mechanisms within the interventions.

Discussion

Nonpharmacological interventions for BPSD should include consideration of both the physical and the social environment, ongoing education/training and support for care providers, and individualized approaches that promote self-determination and continued opportunities for meaning and purpose for persons with dementia.

Can the sensitivity of the histopathological diagnosis of coeliac disease be increased and can treatment progression be monitored using mathematical modelling of histological sections? - A pilot study

PURPOSE

The aim of this pilot study was to attempt to define a set of equations from histological observations of tissue affected with coeliac disease (CD) to predict Marsh score.

MATERIAL/METHODS

Tissue from 15 patients with untreated CD, 6 patients with treated CD and 9 healthy control patients were stained using the standard H&E, Giemsa's staining for tissue sections and Alcian Blue protocols. A number of histological measures were then taken from each section and the data was used to ultimately design a set of linear predictive algorithms to calculate Marsh score.

RESULTS

Using MANOVA and discriminant analysis, two linear functions were defined which could accurately predict the Marsh score of patients 62.5% (full Marsh score) to 79.2% (simplified Marsh score) of the time.

CONCLUSIONS

This pilot study has shown that a set of objective histological measures can be used to define algorithms to predict Marsh score in CD patients and also monitor treatment compliance and progression.

The Canadian Dollar versus the Collection: How Canadian Academic Libraries are Coping

Through 2015 and into 2016, Canadian academic libraries’ collections budgets were severely strained due to the steady decline of the CAD/USD exchange rate. As most subscription fees for electronic resources (e-resources) are billed in US dollars, the falling value of the Canadian dollar significantly reduced libraries’ purchasing power. This study is based on a survey of the English-speaking member institutions of the Canadian Research Knowledge Network (CRKN), a Canadian collections consortium, carried out to determine the impact of the poor exchange rate on collections development and how libraries are coping with new budgetary pressures. Librarians from 33 universities provided survey responses. Of these, 22 participated in telephone interviews to further discuss concerns and ideas regarding the current crisis. The study finds that all participant libraries have taken actions to address the budgetary shortfall, including cancelling serial and database subscriptions, negotiating lower costs with vendors, purchasing fewer monographs, and soliciting additional funding from their institutions. While the financial strain resulting from exchange rate fluctuations is indeed a significant problem for which solutions should be sought, several respondents stressed that it only exacerbates the ongoing inflation of e-resource subscriptions. This deeper and enduring issue, which is expected to outlast the present exchange rate crisis, is enabled by an inherently flawed scholarly publishing system. Thus, librarians engaged in discussions with their wider academic communities concerning collections budgets should not focus exclusively on the exchange rate but should leverage the opportunity to explore alternatives to the current scholarly communication model. If solutions exist, they will likely only be achieved through the support of faculty and university administrators, as well as cooperation among post-secondary institutions and library consortia. Au cours de l’année 2015 et au début 2016, les budgets des collections des bibliothèques universitaires canadiennes ont connu d’importantes restrictions en partie causées par la baisse du dollar canadien face au dollar américain. La plupart des frais d’abonnements aux ressources électroniques sont en dollar américain ce qui signifie que le pouvoir d’achat des bibliothèques a été significativement réduit face à la dévalorisation du dollar canadien. Cette étude utilise un sondage auprès des établissements anglophones qui sont membres du Réseau canadien de documentation pour la recherche (RCDR), un consortium canadien pour les collections, afin de mieux connaître l’impact du faible taux de change sur le développement des collections et sur la façon dont les bibliothèques s’adaptent à de nouvelles pressions budgétaires. Des bibliothécaires de 33 universités ont répondu au sondage. Parmi ceux-ci, 22 ont participé à des entrevues téléphoniques pour discuter davantage de préoccupations et d’idées concernant la crise actuelle. L’étude montre que toutes les bibliothèques participantes ont pris des mesures pour contrer l’insuffisance budgétaire incluant l’annulation d’abonnements de périodiques et de bases de données, la négociation de coûts inférieurs avec les fournisseurs, l’achat de moins de livres ainsi que la sollicitation de financement additionnel auprès de leur institution. Quoique ce stress financier causé par les fluctuations du taux de change représente un sérieux problème pour lequel il faut trouver des solutions, plusieurs répondants ont réitéré que cette réalité ne fait qu’aggraver l’inflation continue des abonnements aux ressources électroniques. Cet enjeu sérieux et persistant, qui risque de perdurer au-delà la crise du taux d’échange actuel, est le résultat d’un système de communication savante défaillant. Les bibliothécaires qui discutent avec leur communauté universitaire au sujet des budgets de collections ne devraient pas se concentrer uniquement sur le taux de change mais devraient en profiter pour explorer des alternatives au modèle de communication savante actuel. Si des solutions existent, elles se réaliseront seulement avec l’appui des professeurs et des administrateurs ainsi qu’avec la coopération entre les établissements postsecondaires et les consortiums des bibliothèques.

A Synthesis of Exiguaquinol Dessulfate

A concise and stereoselective synthesis of exiguaquinol dessulfate is described. Sequential application of a Diels-Alder cycloaddition, a desymmetrizing aldol addition, and a reductive Heck cyclization established most of the architecture of exiguaquinol, and a carefully choreographed introduction of the polar substituents afforded the title compound; unfortunately, naphthoquinol sulfation could not be achieved to deliver exiguaquinol. Our hypothesis regarding the configurational preference of the N-acyl hemiaminal, which was based upon an analysis of internal hydrogen-bonding interactions with polar functional groups, was proven correct. A late-stage intermediate did not demonstrate bactericidal activity against H. pylori cultures.

The role of acid inhibition in Helicobacter pylori eradication

Infection of the stomach by the gastric pathogen Helicobacter pylori results in chronic active gastritis and leads to the development of gastric and duodenal ulcer disease and gastric adenocarcinoma. Eradication of H. pylori infection improves or resolves the associated pathology. Current treatments of H. pylori infection rely on acid suppression in combination with at least two antibiotics. The role of acid suppression in eradication therapy has been variously attributed to antibacterial activity of proton pump inhibitors directly or through inhibition of urease activity or increased stability and activity of antibiotics. Here we discuss the effect of acid suppression on enhanced replicative capacity of H. pylori to permit the bactericidal activity of growth-dependent antibiotics. The future of eradication therapy will rely on improvement of acid inhibition along with current antibiotics or the development of novel compounds targeting the organism's ability to survive in acid.

Eradication of Helicobacter pylori Infection

Helicobacter pylori infects about 50 % of the world's population, causing at a minimum chronic gastritis. A subset of infected patients will ultimately develop gastric or duodenal ulcer disease, gastric adenocarcinoma, or MALT (mucosa-associated lymphoid tissue) lymphoma. Eradication of H. pylori requires complex regimens that include acid suppression and multiple antibiotics. The efficacy of treatment using what were once considered standard regimens have declined in recent years, mainly due to widespread development of antibiotic resistance. Addition of bismuth to standard triple therapy regimens, use of alternate antibiotics, or development of alternative regimens using known therapies in novel combinations have improved treatment efficacy in specific populations, but overall success of eradication remains less than ideal. Novel regimens under investigation either in vivo or in vitro, involving increased acid suppression ideally with fewer antibiotics or development of non-antibiotic treatment targets, show promise for future therapy.

Phosphorylation-dependent and Phosphorylation-independent Regulation of Helicobacter pylori Acid Acclimation by the ArsRS Two-component System

BACKGROUND

The pH-sensitive Helicobacter pylori ArsRS two-component system (TCS) aids survival of this neutralophile in the gastric environment by directly sensing and responding to environmental acidity. ArsS is required for acid-induced trafficking of urease and its accessory proteins to the inner membrane, allowing rapid, urea-dependent cytoplasmic and periplasmic buffering. Expression of ArsR, but not its phosphorylation, is essential for bacterial viability. The aim of this study was to characterize the roles of ArsS and ArsR in the response of H. pylori to acid.

MATERIALS AND METHODS

Wild-type H. pylori and an arsR(D52N) phosphorylation-deficient strain were incubated at acidic or neutral pH. Gene and protein expression, survival, membrane trafficking of urease proteins, urease activity, and internal pH were studied.

RESULTS

Phosphorylation of ArsR is not required for acid survival. ArsS-driven trafficking of urease proteins to the membrane in acid, required for recovery of internal pH, is independent of ArsR phosphorylation. ArsR phosphorylation increases expression of the urease gene cluster, and the loss of negative feedback in a phosphorylation-deficient mutant leads to an increase in total urease activity.

CONCLUSIONS

ArsRS has a dual function in acid acclimation: regulation of urease trafficking to UreI at the cytoplasmic membrane, driven by ArsS, and regulation of urease gene cluster expression, driven by phosphorylation of ArsR. ArsS and ArsR work through phosphorylation-dependent and phosphorylation-independent regulatory mechanisms to impact acid acclimation and allow gastric colonization. Furthering understanding of the intricacies of acid acclimation will impact the future development of targeted, nonantibiotic treatment regimens.

The binding selectivity of vonoprazan (TAK-438) to the gastric H+, K+ -ATPase

BACKGROUND

The gastric H(+) ,K(+) -ATPase is the preferred target for acid suppression. Until recently, the only drugs that effectively inhibited this ATPase were the proton pump inhibitors (PPIs). PPIs are acid-activated prodrugs that require acid protection. Once acid-activated, PPIs bind to cysteines of the ATPase, resulting in covalent, long-lasting inhibition. The short plasma half-life of PPIs and continual de novo synthesis of the H(+) ,K(+) -ATPase result in difficulty controlling night-time acid secretion. A new alternative to PPIs is the pyrrolo-pyridine, vonoprazan (TAK-438), a potassium-competitive acid blocker (PCAB) that does not require acid protection. In contrast to other PCABs, vonoprazan has a long duration of action, resulting in 24-h control of acid secretion, a high pKa of 9.37 and high affinity (Ki = 3.0 ηmol/L).

AIM

To determine binding selectivity of vonoprazan for the gastric H(+) ,K(+) -ATPase and to explain its slow dissociation.

METHODS

Gastric gland and parietal cell binding of vonoprazan was determined radiometrically. Molecular modelling explained the slow dissociation of vonoprazan from the H(+) ,K(+) -ATPase.

RESULTS

Vonoprazan binds selectively to the parietal cell, independent of acid secretion. Vonoprazan binds in a luminal vestibule between the surfaces of membrane helices 4, 5 and 6. Exit of the drug to the lumen is hindered by asp137 and asn138 in the loop between TM1 and TM2, which presents an electrostatic barrier to movement of the sulfonyl group of vonoprazan. This may explain its slow dissociation from the H(+) ,K(+) -ATPase and long-lasting inhibition.

CONCLUSION

The binding model provides a template for design of novel potassium-competitive acid blockers.

Colloidal bismuth subcitrate impedes proton entry into Helicobacter pylori and increases the efficacy of growth-dependent antibiotics

BACKGROUND

Successful eradication of Helicobacter pylori is becoming more difficult, mainly due to emerging antibiotic resistance. Treatment regimens containing bismuth have increased efficacy, but the mechanism is unknown. Helicobacter pylori is a neutralophile adapted to survive the acidic gastric environment via acid acclimation, but demonstrates more robust growth at neutral pH. Many antibiotics used to treat H. pylori rely on bacterial growth.

AIM

To investigate the mechanism of increased efficacy of bismuth-containing H. pylori treatment regimens.

METHODS

RNAseq and qPCR, urease activity in permeabilised and intact bacteria, internal pH and membrane potential were measured with and without colloidal bismuth subcitrate (CBS). Bacterial survival was assessed with CBS and/or ampicillin.

RESULTS

Genes involved with metabolism and growth were upregulated in the presence of CBS at acidic pH. Urease activity of permeabilised H. pylori at pH 7.4 and 4.5 decreased in the presence of CBS, but intact urease activity decreased only at acidic pH. The fall in cytoplasmic pH with external acidification was diminished by CBS. The increase in membrane potential in response to urea addition at acidic medium pH was unaffected by CBS. The impact of CBS and ampicillin on H. pylori survival was greater than either agent alone.

CONCLUSIONS

Bismuth is not acting directly on urease or the urea channel. Colloidal bismuth subcitrate impedes proton entry into the bacteria, leading to a decrease in the expected fall in cytoplasmic pH. With cytoplasmic pH remaining within range for increased metabolic activity of a neutralophile, the efficacy of growth-dependent antibiotics is augmented.

Differential skin test reactivity to pollens in pollen food allergy syndrome versus allergic rhinitis

BACKGROUND

Pollen food allergy syndrome (PFAS), also called oral allergy syndrome, is a form of food allergy in which uncooked foods cause allergic symptoms generally limited to the oral mucosa. It occurs in a subset of patients with pollen allergy, although not all patients have prominent rhinitis symptoms. PFAS is related to antigenic similarity between the pollen and food allergen.

OBJECTIVE

The size of skin test reactions in a group of subjects with pollen sensitivity with PFAS was compared with a group of subjects who were pollen sensitive and without PFAS. Self-reported rhinitis symptoms between the two groups were compared to identify if symptom severity differed.

METHODS

Twenty subjects with PFAS and 20 subjects with seasonal allergic rhinitis without PFAS were enrolled in the study. All the subjects underwent standard skin-prick testing to a panel of common allergens, including select fresh fruits and vegetables. The subjects completed a Mini Rhinoconjunctivitis Quality of Life Questionnaire as part of their clinical evaluation. The subjects with PFAS and those without PFAS were compared statistically.

RESULTS

The subjects with PFAS had significantly larger-sized skin-prick test results specific to pollens (p < 0.05). Despite the larger-sized skin-prick test results, the subjects with allergic rhinitis and PFAS reported milder nasal symptoms in relation to pollen skin test result size when compared with allergic rhinitis controls without PFAS.

CONCLUSIONS

Our study outlined basic differences between two seemingly similar patient groups with a particularly striking discordance between skin test result sizes and rhinitis symptoms. This discordance should be explored further to increase mechanistic understanding of allergen cross-reactivity in PFAS.

Supraesophageal Reflux: Correlation of Position and Occurrence of Acid Reflux-Effect of Head-of-Bed Elevation on Supine Reflux

BACKGROUND

Supraesophageal reflux of gastric contents can contribute to perennial nasopharyngitis, cough, and asthma. However, effective treatment strategies for supraesophageal reflux disease (SERD) remain inadequately defined.

OBJECTIVE

The purpose of this study is to assess the prevalence and timing of SERD and to investigate the efficacy of head-of-bed elevation in its treatment.

METHODS

A retrospective chart review of patients seen at Scripps Clinic Division of Allergy, Asthma and Immunology was performed who had undergone overnight nasopharyngeal pH monitoring with a commercially available nasopharyngeal pH-monitoring device, Dx-pH Measurement System from Restech, San Diego, Calif. Subjects with reflux were classified based on the position of reflux as either supine only, upright only, or both supine and upright. In a subset of subjects with supine-only reflux, pH monitoring was compared before and after elevating the head of bed 6 inches.

RESULTS

Adequate nasopharyngeal pH-monitoring data were obtained for 235 patients. Reflux was detected in 113 (48%) patients. The pattern of reflux observed was 62 (55%) supine only, 4 (4%) upright only, and 47 (42%) upright and supine. Sequential overnight nasopharyngeal pH monitoring before and after head-of-bed elevation was obtained in 13 individuals with supine-only reflux. Ten subjects demonstrated significant improvement, 8 of whom demonstrated complete resolution of supine reflux with 6 inches of head-of-bed elevation.

CONCLUSION

This study provides new evidence that SERD frequently occurs in the supine position and that 6 inches of head-of-bed elevation is effective in reducing supine SERD.

Increased ILC2s in the eosinophilic nasal polyp endotype are associated with corticosteroid responsiveness

Group 2 innate lymphoid cells (ILC2s) have recently been identified in human nasal polyps, but whether numbers of ILC2s differ by polyp endotype or are influenced by corticosteroid use is unknown. Here, we show that eosinophilic nasal polyps contained double the number of ILC2s vs. non-eosinophilic polyps. Polyp ILC2s were also reduced by 50% in patients treated with systemic corticosteroids. Further, using a fungal allergen challenge mouse model, we detected greatly reduced Th2 cytokine-producing and Ki-67+ proliferating lung ILC2s in mice receiving dexamethasone. Finally, ILC2 Annexin V staining revealed extensive apoptosis after corticosteroid treatment in vivo and in vitro. Thus, ILC2s are elevated in the eosinophilic nasal polyp endotype and systemic corticosteroid treatment correlated with reduced polyp ILC2s. Finally, allergen-challenged mice showed reduced ILC2s and increased ILC2 apoptosis after corticosteroid treatment suggesting that ILC2 may be responsive to corticosteroids in eosinophilic respiratory disease.

Supraesophageal reflux disease: a review of the literature

Supraesophageal reflux disease (SERD), defined as reflux proximal to the upper esophageal sphincter, is a common cause of morbidity of the upper aerodigestive tract, including rhinitis, laryngitis, cough, postnasal drip, and throat clearing. Although SERD has a high prevalence, the ideal means of diagnosing and treating the disease remain poorly defined. Evolving pH monitoring technology and a body of literature with conflicting reports regarding the best means for measuring and interpreting supraesophageal acidic reflux complicates the diagnosis of SERD. Treatment options include empiric acid suppression therapy, lifestyle modification, and surgery. However, limited data regarding the effectiveness of these strategies vary between studies and patient populations. It is the goal of this article to summarize the presentation and pathogenesis of SERD and to integrate the evolving body of literature pertaining to diagnostic and treatment strategies.

Helicobacter pylori impedes acid-induced tightening of gastric epithelial junctions

Gastric infection by Helicobacter pylori is the most common cause of ulcer disease and gastric cancer. The mechanism of progression from gastritis and inflammation to ulcers and cancer in a fraction of those infected is not definitively known. Significant acidity is unique to the gastric environment and is required for ulcer development. The interplay between gastric acidity and H. pylori pathogenesis is important in progression to advanced disease. The aim of this study was to characterize the impact of acid on gastric epithelial integrity and cytokine release and how H. pylori infection alters these responses. Human gastric epithelial (HGE-20) cells were grown on porous inserts, and survival, barrier function, and cytokine release were studied at various apical pH levels in the presence and absence of H. pylori. With apical acidity, gastric epithelial cells demonstrate increased barrier function, as evidenced by increased transepithelial electrical resistance (TEER) and decreased paracellular permeability. This effect is reduced in the presence of wild-type, but not urease knockout, H. pylori. The epithelial inflammatory response is also modulated by acidity and H. pylori infection. Without H. pylori, epithelial IL-8 release decreases in acid, while IL-6 release increases. In the presence of H. pylori, acidic pH diminishes the magnitude of the previously reported increase in IL-8 and IL-6 release. H. pylori interferes with the gastric epithelial response to acid, contributing to altered barrier function and inflammatory response. H. pylori diminishes acid-induced tightening of cell junctions in a urease-dependent manner, suggesting that local pH elevation promotes barrier compromise and progression to mucosal damage.

The role of ExbD in periplasmic pH homeostasis in Helicobacter pylori

BACKGROUND

Helicobacter pylori, a neutralophile, colonizes the acidic environment of the human stomach by employing acid acclimation mechanisms that regulate periplasmic and cytoplasmic pH. The regulation of urease activity is central to acid acclimation. Inactive urease apoenzyme, UreA/B, requires nickel for activation. Accessory proteins UreE, F, G, and H are required for nickel insertion into apoenzyme. The ExbB/ExbD/TonB complex transfers energy from the inner to outer membrane, providing the driving force for nickel uptake. Therefore, the aim of this study was to determine the contribution of ExbD to pH homeostasis.

MATERIALS AND METHODS

A nonpolar exbD knockout was constructed and survival, growth, urease activity, and membrane potential were determined in comparison with wildtype.

RESULTS

Survival of the ΔexbD strain was significantly reduced at pH 3.0. Urease activity as a function of pH and UreI activation was similar to the wildtype strain, showing normal function of the proton-gated urea channel, UreI. The increase in total urease activity over time in acid seen in the wildtype strain was abolished in the ΔexbD strain, but recovered in the presence of supraphysiologic nickel concentrations, demonstrating that the effect of the ΔexbD mutant is due to loss of a necessary constant supply of nickel. In acid, ΔexbD also decreased its ability to maintain membrane potential and periplasmic buffering in the presence of urea.

CONCLUSIONS

ExbD is essential for maintenance of periplasmic buffering and membrane potential by transferring energy required for nickel uptake, making it a potential nonantibiotic target for H. pylori eradication.

Recurrent fevers and failure to thrive in an infant

We describe a 2-year old boy with consanguineous parents who recently emigrated from India and presented with oral ulcers and lymphadenopathy. He also had a history of recurrent fevers, polyarticular arthritis, chronic diarrhea, failure to thrive, and developmental delay. Infectious workup revealed herpes simplex virus 1 viremia and radiological evaluation revealed osteopenia and erosions involving multiple joints. We describe the immunologic and genetic evaluation of this patient and discuss the diagnostic and therapeutic approach to an infant with recurrent fevers.

Acid stress increases gene expression of proinflammatory cytokines in Madin-Darby canine kidney cells

Metabolic acidosis is thought to exacerbate chronic kidney disease in part by stimulating the release of potentially injurious substances. To define the genes whose expression is affected by exposure to an acidic milieus, we examined the effect of exposure of MDCK cells to pH 7.4 and pH 7.0 for 24 h on gene expression using a canine derived microarray. Exposure to this pH stress for 24 h led to increased expression of 278 genes (2.2% of the transcriptome) by at least 2-fold and 60 of these (21%) were upregulated by >3-fold. On the other hand, 186 genes (1.5% of the transcriptome) were downregulated by at least 2-fold and 16 of these (9%) were downregulated by 3-fold or more. Ten percent of the genes upregulated by at least threefold encode proinflammatory cytokine proteins, including colony stimulating factor 2, chemokine ligand 7, chemokine ligand 20, chemokine ligand 8, and interleukin-1α. Two others encode metallopeptidases. The most highly upregulated gene encodes a protein, lubricin, shown to be important in preventing cartilage damage and in tissue injury or repair. Upregulation of four genes was confirmed by quantitative PCR. Housekeeping genes were not increased. To examine the effect of decreasing medium pH, we measured intracellular pH (pHi) using 2,7-bis (2-carboxyethyl)5-carboxyfluorescein. With extracellular pH (pHo) of 7.0, pHi fell and remained depressed. These findings suggest that a pH stress alone can increase renal expression of proinflammatory and other genes that contribute to renal injury.

The effects of varying acidity on Helicobacter pylori growth and the bactericidal efficacy of ampicillin

BACKGROUND

Penicillins inhibit cell wall synthesis; therefore, Helicobacter pylori must be dividing for this class of antibiotics to be effective in eradication therapy. Identifying growth responses to varying medium pH may allow design of more effective treatment regimens.

AIM

To determine the effects of acidity on bacterial growth and the bactericidal efficacy of ampicillin.

METHODS

H. pylori were incubated in dialysis chambers suspended in 1.5-L of media at various pHs with 5 mM urea, with or without ampicillin, for 4, 8 or 16 h, thus mimicking unbuffered gastric juice. Changes in gene expression, viability and survival were determined.

RESULTS

At pH 3.0, but not at pH 4.5 or 7.4, there was decreased expression of ~400 genes, including many cell envelope biosynthesis, cell division and penicillin-binding protein genes. Ampicillin was bactericidal at pH 4.5 and 7.4, but not at pH 3.0.

CONCLUSIONS

Ampicillin is bactericidal at pH 4.5 and 7.4, but not at pH 3.0, due to decreased expression of cell envelope and division genes with loss of cell division at pH 3.0. Therefore, at pH 3.0, the likely pH at the gastric surface, the bacteria are nondividing and persist with ampicillin treatment. A more effective inhibitor of acid secretion that maintains gastric pH near neutrality for 24 h/day should enhance the efficacy of amoxicillin, improving triple therapy and likely even allowing dual amoxicillin-based therapy for H. pylori eradication.

Clinical human papillomavirus detection forecasts cervical cancer risk in women over 18 years of follow-up

PURPOSE

To describe the long-term (≥ 10 years) benefits of clinical human papillomavirus (HPV) DNA testing for cervical precancer and cancer risk prediction.

METHODS

Cervicovaginal lavages collected from 19,512 women attending a health maintenance program were retrospectively tested for HPV using a clinical test. HPV positives were tested for HPV16 and HPV18 individually using a research test. A Papanicolaou (Pap) result classified as atypical squamous cells of undetermined significance (ASC-US) or more severe was considered abnormal. Women underwent follow-up prospectively with routine annual Pap testing up to 18 years. Cumulative incidence rates (CIRs) of ≥ grade 3 cervical intraepithelial neoplasia (CIN3+) or cancer for enrollment test results were calculated.

RESULTS

A baseline negative HPV test provided greater reassurance against CIN3+ over the 18-year follow-up than a normal Pap (CIR, 0.90% v 1.27%). Although both baseline Pap and HPV tests predicted who would develop CIN3+ within the first 2 years of follow-up, only HPV testing predicted who would develop CIN3+ 10 to 18 years later (P = .004). HPV16- and HPV18-positive women with normal Pap were at elevated risk of CIN3+ compared with other HPV-positive women with normal Pap and were at similar risk of CIN3+ compared with women with a low-grade squamous intraepithelial Pap.

CONCLUSION

HPV testing to rule out cervical disease followed by Pap testing and possibly combined with the detection of HPV16 and HPV18 among HPV positives to identify those at immediate risk of CIN3+ would be an efficient algorithm for cervical cancer screening, especially in women age 30 years or older.

Helicobacter pylori: Eradication or Preservation

Helicobacter pylori infects about 50% of the world's population and inevitably results in the development of gastritis. Of those infected, about 10% develop peptic ulcer disease and roughly 1% develop gastric cancer. Conversely, some take the view that H. pylori infection provides some protection against gastro-esophageal reflux disease and possibly asthma. This review aims to explore the case for and against eradication of the bacterium using a "test and treat" approach amongst the general population.

A novel approach to increase residents' involvement in reporting adverse events

PURPOSE

In the wake of the Patient Safety and Quality Improvement Act of 2005, national attention has increasingly focused on adverse-event reporting as a means of identifying systems changes to improve patient safety. However, physicians and residents have demonstrated meager involvement in this effort.

METHOD

In 2008-2009, the authors measured participation in adverse-event reporting by 680 residents at Oregon Health & Science University before and after implementing a quality improvement initiative, which consisted of a financial incentive and multifaceted educational campaign. The primary measure of success was an increase in the average monthly adverse-event reports submitted by residents to greater than 5% of the institution's overall report submissions.

RESULTS

The average number of adverse events reported by residents increased from 1.6% to 9.0% of the institution's overall event reports, representing a 5.6-fold increase during the initiative (P < .001). The relative percentage of resident-submitted reports defined as "near-misses" increased from 6% to 27% during the initiative (P < .001).

CONCLUSIONS

The novel approach of integrating a retirement benefit and educational campaign to increase residents' involvement in adverse-event reporting was successful. In addition to increasing residents' contributions to adverse-event reporting to levels higher than any documented in the current literature, there was also a remarkable increase in the relative frequency of near-miss reporting by residents.

A long-term prospective study of type-specific human papillomavirus infection and risk of cervical neoplasia among 20,000 women in the Portland Kaiser Cohort Study

BACKGROUND

Human papillomavirus (HPV) DNA testing is more sensitive than cytology for detection of cervical intraepithelial neoplasia grade 3 and cancer (≥CIN3). Adding HPV testing to cytology is recommended for women ≥30 but long-term prospective studies of HPV testing are rare.

METHODS

Beginning in 1989-1990, ~20,000 women in a prepaid health maintenance organization (median age = 34) were followed passively by recommended annual cytology. We tested archived cervicovaginal lavage specimens collected at enrollment, primarily by MY09-MY11 PCR-based methods, for carcinogenic HPV types. We calculated positive and negative predictive values for the entire study period, and Kaplan-Meier estimates of cumulative probability for ≥CIN3, up to 18 years of follow-up.

RESULTS

We observed 47 cases of invasive cervical cancer during the study period, and 156 cases of CIN3. Predictive values and Kaplan-Meier analyses yielded the same conclusions. In women 30 and older, the reassurance against ≥CIN3 following a single negative HPV test was long-lasting (cumulative probability = 0.7% during follow-up). In this age group, a single HPV test (positive vs. negative, hazard ratio of 8.5, 95% CI = 4.8-15.1) provided greater long-term risk stratification than a single cytologic result (abnormal vs. normal, HR = 2.9, 95% CI = 1.2-6.6). The risk for ≥CIN3 was higher for HPV16 than for the average of the other carcinogenic types (hazard ratio = 2.7).

CONCLUSION AND IMPACT

The data from this cohort study show the long-term predictive value of HPV testing, particularly in women ≥30, and a possible role for distinguishing particularly carcinogenic types like HPV16.

Liver transient elastography (Fibroscan): a place in the management algorithms of chronic viral hepatitis

Treatment guidelines are continuously evolving in chronic viral hepatitis, taking into consideration our greater understanding of natural history and therapeutic efficacy and safety. Key in the decision making process is an assessment of liver injury. Traditionally, liver biopsy has provided this information; however, this is an invasive procedure and not completely reliable. Liver transient elastography (Fibroscan) is exciting new technology that allows estimation of hepatic fibrosis through measurement of liver stiffness. It is acceptably accurate, safe, cheap, quick and widely applicable, and can reduce the need for liver biopsy in chronic hepatitis. In chronic hepatitis C, it can identify those most likely to benefit from treatment, as well as those with cirrhosis who require more specific care. In chronic hepatitis B, it could screen groups previously excluded from treatment (normal alanine aminotransferase and low DNA) to identify the subgroup that would benefit from therapy. It cannot replace biopsy in all settings, but it will narrow the group who do require biopsy, and provide information on liver damage in patients for whom biopsy would probably not have been considered.

Access and care issues in urban urgent care clinic patients

Background

Although primary care should be the cornerstone of medical practice, inappropriate use of urgent care for non-urgent patients is a growing problem that has significant economic and healthcare consequences. The characteristics of patients who choose the urgent care setting, as well as the reasoning behind their decisions, is not well established. The purpose of this study was to determine the motivation behind, and characteristics of, adult patients who choose to access health care in our urgent care clinic. The relevance of understanding the motivation driving this patient population is especially pertinent given recent trends towards universal healthcare and the unclear impact it may have on the demands of urgent care.

Methods

We conducted a cross-sectional survey of patients seeking care at an urgent care clinic (UCC) within a large acute care safety-net urban hospital over a six-week period. Survey data included demographics, social and economic information, reasons that patients chose a UCC, previous primary care exposure, reasons for delaying care, and preventive care needs.

Results

A total of 1, 006 patients were randomly surveyed. Twenty-five percent of patients identified Spanish as their preferred language. Fifty-four percent of patients reported choosing the UCC due to not having to make an appointment, 51.2% because it was convenient, 43.9% because of same day test results, 42.7% because of ability to get same-day medications and 15.1% because co-payment was not mandatory. Lack of a regular physician was reported by 67.9% of patients and 57.2% lacked a regular source of care. Patients reported delaying access to care for a variety of reasons.

Conclusion

Despite a common belief that patients seek care in the urgent care setting primarily for economic reasons, this study suggests that patients choose the urgent care setting based largely on convenience and more timely care. This information is especially applicable to the potential increase in urgent care volume in a universal healthcare system. Additionally, this study adds to the body of literature supporting the important role of timely primary care in healthcare maintenance.

Polycyclic aromatic hydrocarbon-DNA adducts in cervix of women infected with carcinogenic human papillomavirus types: an immunohistochemistry study

Among women infected with carcinogenic human papillomavirus (HPV), there is a two- to five-fold increased risk of cervical precancer and cancer in women who smoke compared to those who do not smoke. Because tobacco smoke contains carcinogenic polycyclic aromatic hydrocarbons (PAHs), it was of interest to examine human cervical tissue for PAH-DNA adduct formation. Here, we measured PAH-DNA adduct formation in cervical biopsies collected in follow-up among women who tested positive for carcinogenic HPV at baseline. A semi-quantitative immunohistochemistry (IHC) method using antiserum elicited against DNA modified with r7,t8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE) was used to measure nuclear PAH-DNA adduct formation. Cultured human cervical keratinocytes exposed to 0, 0.153, or 0.331microM BPDE showed dose-dependent increases in r7,t8,t9-trihydroxy-c-10-(N(2)deoxyguanosyl)-7,8,9,10-tetrahydro-benzo[a]pyrene (BPdG) adducts. For BPdG adduct analysis, paraffin-embedded keratinocytes were stained by IHC with analysis of nuclear color intensity by Automated Cellular Imaging System (ACIS) and, in parallel cultures, extracted DNA was assayed by quantitative BPDE-DNA chemiluminescence immunoassay (CIA). For paraffin-embedded samples from carcinogenic HPV-infected women, normal-appearing cervical squamous epithelium suitable for scoring was found in samples from 75 of the 114 individuals, including 29 cases of cervical precancer or cancer and 46 controls. With a lower limit of detection of 20 adducts/10(8) nucleotides, detectable PAH-DNA adduct values ranged from 25 to 191/10(8) nucleotides, with a median of 75/10(8) nucleotides. PAH-DNA adduct values above 150/10(8) nucleotides were found in eight samples, and in three samples adducts were non-detectable. There was no correlation between PAH-DNA adduct formation and either smoking or case status. Therefore, PAH-DNA adduct formation as measured by this methodology did not appear related to the increased risk of cervical precancer and cancer among carcinogenic HPV-infected smokers.

Gene expression in vivo shows that Helicobacter pylori colonizes an acidic niche on the gastric surface

Helicobacter pylori is a gastric-dwelling pathogen responsible, with acid secretion, for peptic ulcer and a 20-fold increase in the risk of gastric cancer. Several transcriptomes have been described after short-term exposure to acidity in vitro, but there are no data identifying the effects of chronic gastric exposure on bacterial gene expression. Comparison of the in vivo to the in vitro transcriptome at pH 7.4 identified several groups of genes of known function that increased expression >2-fold, and three of these respond both to acidity in vitro and to gastric infection. Almost all known acid acclimation genes are highly up-regulated. These include ureA, ureB, and rocF and the pH-gated urea channel, ureI. There is also up-regulation of two groups of motility and chemotaxis genes and for pathogenicity island genes, especially cagA, a predictor for pathogenicity. Most of these genes interact with HP0166, the response element of the pH-sensing two-component histidine kinase, HP0165/HP0166, ArsRS. Based on the pH profile of survival of ureI deletion mutants in vitro and their inability to survive in gastric acidity, the habitat of the organism at the gastric surface is acidic with a pH < or = 4.0. Hence, the pH of the habitat of H. pylori on the surface of the stomach largely determines the regulation of these specific groups of genes.

Urea transport in bacteria: acid acclimation by gastric Helicobacter spp

Urea transporters in bacteria are relatively rare. There are three classes, the ABC transporters such as those expressed by cyanobacteria and Corynebacterium glutamicum, the Yut protein expressed by Yersinia spp and the UreI expressed by gastric Helicobacter spp. This review focuses largely on the UreI proton-gated channel that is part of the acid acclimation mechanism essential for gastric colonization by the latter. UreI is a six-transmembrane polytopic integral membrane protein, N and C termini periplasmic, and is expressed in all gastric Helicobacter spp that have been studied but also in Helicobacter hepaticus and Streptococcus salivarius. The first two are proton-gated, the latter is pH insensitive. Site-directed mutagenesis and chimeric constructs have identified histidines and dicarboxylic amino acids in the second periplasmic loop of H. pylori and the first loop of H. hepaticus UreI and the C terminus of both as involved in a hydrogen-bonding dependence of proton gating, with the membrane domain in these but not in the UreI of S. salivarius responding to the periplasmic conformational changes. UreI and urease are essential for gastric colonization and urease associates with UreI during acid exposure, facilitating activation of the UreA and UreB apoenzyme complex by Ni2+ insertion by the UreF-UreH and UreE-UreG assembly proteins. Transcriptome analysis of acid responses of H. pylori also identified a cytoplasmic and periplasmic carbonic anhydrase as responding specifically to changes in periplasmic pH and these have been shown to be essential also for acid acclimation. The finding also of upregulation of the two-component histidine kinase HP0165 and its response element HP0166, illustrates the complexity of the acid acclimation processes involved in gastric colonization by this pathogen.

The HP0165-HP0166 two-component system (ArsRS) regulates acid-induced expression of HP1186 alpha-carbonic anhydrase in Helicobacter pylori by activating the pH-dependent promoter

The periplasmic alpha-carbonic anhydrase of Helicobacter pylori is essential for buffering the periplasm at acidic pH. This enzyme is an integral component of the acid acclimation response that allows this neutralophile to colonize the stomach. Transcription of the HP1186 alpha-carbonic anhydrase gene is upregulated in response to low environmental pH. A binding site for the HP0166 response regulator (ArsR) has been identified in the promoter region of the HP1186 gene. To investigate the mechanism that regulates the expression of HP1186 in response to low pH and the role of the HP0165-HP0166 two-component system (ArsRS) in this acid-inducible regulation, Northern blot analysis was performed with RNAs isolated from two different wild-type H. pylori strains (26695 and 43504) and mutants with HP0165 histidine kinase (ArsS) deletions, after exposure to either neutral pH or low pH (pH 4.5). ArsS-dependent upregulation of HP1186 alpha-carbonic anhydrase in response to low pH was found in both strains. Western blot analysis of H. pylori membrane proteins confirmed the regulatory role of ArsS in HP1186 expression in response to low pH. Analysis of the HP1186 promoter region revealed two possible transcription start points (TSP1 and TSP2) located 43 and 11 bp 5' of the ATG start codon, respectively, suggesting that there are two promoters transcribing the HP1186 gene. Quantitative primer extension analysis showed that the promoter from TSP1 (43 bp 5' of the ATG start codon) is a pH-dependent promoter and is regulated by ArsRS in combating environmental acidity, whereas the promoter from TSP2 may be responsible for control of the basal transcription of HP1186 alpha-carbonic anhydrase.

Human papillomavirus prevalence in women who have and have not undergone hysterectomies

We compared human papillomavirus (HPV) prevalence in an age-stratified random sample of women who have undergone a hysterectomy (WH) (n=573) with the HPV prevalence in age-matched women with intact cervices (women who have not undergone a hysterectomy [WNH]) (n=581) participating in a study at Kaiser Permanente in Portland, Oregon. Testing cervicovaginal lavage fluids for >40 HPV genotypes using an MY09/11 L1 consensus primer polymerase chain reaction method, we found no statistical differences in the prevalence of HPV (16% for WNH vs. 13.9% for WH) or carcinogenic HPV (6.5% for WNH vs. 4.5% for WH) between the 2 groups of women. Although WH have a similar prevalence of carcinogenic HPV infection, compared with WNH without a cervix, they have minimal risk of HPV-induced cancer and are unlikely to benefit from HPV testing.

Cervical HPV DNA detection as a predictor of a recurrent SIL diagnosis among untreated women

OBJECTIVES

This study was conducted to test whether patient history of untreated cervical intraepithelial neoplasia (CIN) 1 or low-grade squamous intraepithelial lesions (LGSIL) modifies the interpretation of a positive HPV DNA result with regards to subsequent squamous intraepithelial lesions (SIL).

METHODS

Seventy-three women with recurrent SIL were compared to 105 controls who remain cytologically normal during follow up. Cervical samples collected at enrollment were assayed for HPV DNA in the subject and control groups.

RESULTS

Women with and without a history of LGSIL who tested positive for HPV DNA were at a similarly increased risk of having (recurrent) LGSIL as compared to controls. However, in women with a history of LGSIL, HPV DNA appeared to be less predictive for high-grade squamous intraepithelial lesions (HGSIL) than in women without a history of disease.

CONCLUSIONS

Past history of untreated CIN1 or LGSIL does not modify the predictive value of a positive HPV DNA test for subsequent LGSIL. The observed difference of the predictive value of a positive HPV DNA test for the risk of recurrent HSIL compared to incident HSIL should be pursued.

Involvement of the HP0165-HP0166 two-component system in expression of some acidic-pH-upregulated genes of Helicobacter pylori

About 200 genes of the gastric pathogen Helicobacter pylori increase expression at medium pHs of 6.2, 5.5, and 4.5, an increase that is abolished or much reduced by the buffering action of urease. Genes up-regulated by a low pH include the two-component system HP0165-HP0166, suggesting a role in the regulation of some of the pH-sensitive genes. To identify targets of HP0165-HP0166, the promoter regions of genes up-regulated by a low pH were grouped based on sequence similarity. Probes for promoter sequences representing each group were subjected to electrophoretic mobility shift assays (EMSA) with recombinant HP0166-His(6) or a mutated response regulator, HP0166-D52N-His(6), that can specifically determine the role of phosphorylation of HP0166 in binding (including a control EMSA with in-vitro-phosphorylated HP0166-His(6)). Nineteen of 45 promoter-regulatory regions were found to interact with HP0166-His(6). Seven promoters for genes encoding alpha-carbonic anhydrase, omp11, fecD, lpp20, hypA, and two with unknown function (pHP1397-1396 and pHP0654-0675) were clustered in gene group A, which may respond to changes in the periplasmic pH at a constant cytoplasmic pH and showed phosphorylation-dependent binding in EMSA with HP0166-D52N-His(6). Twelve promoters were clustered in groups B and C whose up-regulation likely also depends on a reduction of the cytoplasmic pH at a medium pH of 5.5 or 4.5. Most of the target promoters in groups B and C showed phosphorylation-dependent binding with HP0166-D52N-His(6), but promoters for ompR (pHP0166-0162), pHP0682-0681, and pHP1288-1289 showed phosphorylation-independent binding. These findings, combined with DNase I footprinting, suggest that HP0165-0166 is an acid-responsive signaling system affecting the expression of pH-sensitive genes. Regulation of these genes responds either to a decrease in the periplasmic pH alone (HP0165 dependent) or also to a decrease in the cytoplasmic pH (HP0165 independent).

Acid acclimation by Helicobacter pylori

Helicobacter pylori is a Gram-negative neutralophile associated with peptic ulcers and gastric cancer. It has a unique ability to colonize the human stomach by acid acclimation. It uses the pH-gated urea channel, UreI, to enhance urea access to intrabacterial urease and a membrane-anchored periplasmic carbonic anhydrase to regulate periplasmic pH to approximately 6.1 in acidic media, whereas other neutralophiles cannot regulate periplasmic pH and thus only transit the stomach.