Demonstrating paths for unlocking the value of cloud genomics through cross cohort analysis

Recently, large scale genomic projects such as All of Us and the UK Biobank have introduced a new research paradigm where data are stored centrally in cloud-based Trusted Research Environments (TREs). To characterize the advantages and drawbacks of different TRE attributes in facilitating cross-cohort analysis, we conduct a Genome-Wide Association Study of standard lipid measures using two approaches: meta-analysis and pooled analysis. Comparison of full summary data from both approaches with an external study shows strong correlation of known loci with lipid levels (R2 ~ 83-97%). Importantly, 90 variants meet the significance threshold only in the meta-analysis and 64 variants are significant only in pooled analysis, with approximately 20% of variants in each of those groups being most prevalent in non-European, non-Asian ancestry individuals. These findings have important implications, as technical and policy choices lead to cross-cohort analyses generating similar, but not identical results, particularly for non-European ancestral populations.

Examining sociodemographic correlates of opioid use, misuse, and use disorders in the All of Us Research Program

BACKGROUND

The All of Us Research Program enrolls diverse US participants which provide a unique opportunity to better understand the problem of opioid use. This study aims to estimate the prevalence of opioid use and its association with sociodemographic characteristics from survey data and electronic health record (EHR).

METHODS

A total of 214,206 participants were included in this study who competed survey modules and shared EHR data. Adjusted logistic regressions were used to explore the associations between sociodemographic characteristics and opioid use.

RESULTS

The lifetime prevalence of street opioids was 4%, and the nonmedical use of prescription opioids was 9%. Men had higher odds of lifetime opioid use (aOR: 1.4 to 3.1) but reduced odds of current nonmedical use of prescription opioids (aOR: 0.6). Participants from other racial and ethnic groups were at reduced odds of lifetime use (aOR: 0.2 to 0.9) but increased odds of current use (aOR: 1.9 to 9.9) compared with non-Hispanic White participants. Foreign-born participants were at reduced risks of opioid use and diagnosed with opioid use disorders (OUD) compared with US-born participants (aOR: 0.36 to 0.67). Men, Younger, White, and US-born participants are more likely to have OUD.

CONCLUSIONS

All of Us research data can be used as an indicator of national trends for monitoring the prevalence of receiving prescription opioids, diagnosis of OUD, and non-medical use of opioids in the US. The program employs a longitudinal design for routinely collecting health-related data including EHR data, that will contribute to the literature by providing important clinical information related to opioids over time. Additionally, this data will enhance the estimates of the prevalence of OUD among diverse populations, including groups that are underrepresented in the national survey data.

Achieving a Representative Sample of Asian Americans in Biomedical Research Through Community-Based Approaches: Comparing Demographic Data in the All of Us Research Program With the American Community Survey

BACKGROUND

Underrepresented persons are often not included in biomedical research. It is unknown if the general Asian American population is being represented in All of Us. The purpose of this study was to compare the Asian demographic data in the All of Us cohort with the Asian nationally representative data from the American Community Survey.

METHOD

Demographic characteristics and health literacy of Asians in All of Us were examined. Findings were qualitatively compared with the Asian data in the 2019 American Community Survey 1-year estimate.

RESULTS

Compared with the national composition of Asians, less All of Us participants were born outside the United States (64% vs 79%), were younger, and had higher levels of education (76% vs 52%). Over 60% of All of Us participants reported high levels of health literacy.

CONCLUSION

This study had implications for the development of strategies that ensure diverse populations are represented in biomedical research.

Investigation of hypertension and type 2 diabetes as risk factors for dementia in the All of Us cohort

The World Health Organization recently defined hypertension and type 2 diabetes (T2D) as modifiable comorbidities leading to dementia and Alzheimer's disease. In the United States (US), hypertension and T2D are health disparities, with higher prevalence seen for Black and Hispanic minority groups compared to the majority White population. We hypothesized that elevated prevalence of hypertension and T2D risk factors in Black and Hispanic groups may be associated with dementia disparities. We interrogated this hypothesis using a cross-sectional analysis of participant data from the All of Us (AoU) Research Program, a large observational cohort study of US residents. The specific objectives of our study were: (1) to compare the prevalence of dementia, hypertension, and T2D in the AoU cohort to previously reported prevalence values for the US population, (2) to investigate the association of hypertension, T2D, and race/ethnicity with dementia, and (3) to investigate whether race/ethnicity modify the association of hypertension and T2D with dementia. AoU participants were recruited from 2018 to 2019 as part of the initial project cohort (R2019Q4R3). Participants aged 40-80 with electronic health records and demographic data (age, sex, race, and ethnicity) were included for analysis, yielding a final cohort of 125,637 individuals. AoU participants show similar prevalence of hypertension (32.1%) and T2D (13.9%) compared to the US population (32.0% and 10.5%, respectively); however, the prevalence of dementia for AoU participants (0.44%) is an order of magnitude lower than seen for the US population (5%). AoU participants with dementia show a higher prevalence of hypertension (81.6% vs. 31.9%) and T2D (45.9% vs. 11.4%) compared to non-dementia participants. Dominance analysis of a multivariable logistic regression model with dementia as the outcome shows that hypertension, age, and T2D have the strongest associations with dementia. Hispanic was the only race/ethnicity group that showed a significant association with dementia, and the association of sex with dementia was non-significant. The association of T2D with dementia is likely explained by concurrent hypertension, since > 90% of participants with T2D also had hypertension. Black race and Hispanic ethnicity interact with hypertension, but not T2D, to increase the odds of dementia. This study underscores the utility of the AoU participant cohort to study disease prevalence and risk factors. We do notice a lower participation of aged minorities and participants with dementia, revealing an opportunity for targeted engagement. Our results indicate that targeting hypertension should be a priority for risk factor modifications to reduce dementia incidence.

An Overview of Cancer in the First 315,000 All of Us Participants

Introduction

The NIH All of Us Research Program will have the scale and scope to enable research for a wide range of diseases, including cancer. The program’s focus on diversity and inclusion promises a better understanding of the unequal burden of cancer. Preliminary cancer ascertainment in the All of Us cohort from two data sources (self-reported versus electronic health records (EHR)) is considered.

Materials and methods

This work was performed on data collected from the All of Us Research Program’s 315,297 enrolled participants to date using the Researcher Workbench, where approved researchers can access and analyze All of Us data on cancer and other diseases. Cancer case ascertainment was performed using data from EHR and self-reported surveys across key factors. Distribution of cancer types and concordance of data sources by cancer site and demographics is analyzed.

Results and discussion

Data collected from 315,297 participants resulted in 13,298 cancer cases detected in the survey (in 89,261 participants), 23,520 cancer cases detected in the EHR (in 203,813 participants), and 7,123 cancer cases detected across both sources (in 62,497 participants). Key differences in survey completion by race/ethnicity impacted the makeup of cohorts when compared to cancer in the EHR and national NCI SEER data.

Conclusions

This study provides key insight into cancer detection in the All of Us Research Program and points to the existing strengths and limitations of All of Us as a platform for cancer research now and in the future.

The All of Us Research Program: Data quality, utility, and diversity

The All of Us Research Program seeks to engage at least one million diverse participants to advance precision medicine and improve human health. We describe here the cloud-based Researcher Workbench that uses a data passport model to democratize access to analytical tools and participant information including survey, physical measurement, and electronic health record (EHR) data. We also present validation study findings for several common complex diseases to demonstrate use of this novel platform in 315,000 participants, 78% of whom are from groups historically underrepresented in biomedical research, including 49% self-reporting non-White races. Replication findings include medication usage pattern differences by race in depression and type 2 diabetes, validation of known cancer associations with smoking, and calculation of cardiovascular risk scores by reported race effects. The cloud-based Researcher Workbench represents an important advance in enabling secure access for a broad range of researchers to this large resource and analytical tools.

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The All of Us Research Program has released data for over 315,000 participants

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Demonstration projects support the utility and validity of the All of Us dataset

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The cloud-based Researcher Workbench provides secure, low-cost compute power

The engagement of participants in the research process and broad availability of data to diverse researchers are essential elements in building precision medicine equitably available for all. The NIH has established the ambitious All of Us Research Program to build one of the most diverse health databases in history with tools to support research to improve human health. Here, we present the initial launch of the Researcher Workbench with data types including surveys, physical measurements, and electronic health record data with validation studies to support researcher use of this novel platform. Broad access for researchers to data like these is a critical step in returning value to participants seeking to support the advancement of precision medicine and improved health for all.

Geographic Variation in Obesity at the State Level in the All of Us Research Program

INTRODUCTION

National obesity prevention strategies may benefit from precision health approaches involving diverse participants in population health studies. We used cohort data from the National Institutes of Health All of Us Research Program (All of Us) Researcher Workbench to estimate population-level obesity prevalence.

METHODS

To estimate state-level obesity prevalence we used data from physical measurements made during All of Us enrollment visits and data from participant electronic health records (EHRs) where available. Prevalence estimates were calculated and mapped by state for 2 categories of body mass index (BMI) (kg/m2): obesity (BMI >30) and severe obesity (BMI >35). We calculated and mapped prevalence by state, excluding states with fewer than 100 All of Us participants.

RESULTS

Data on height and weight were available for 244,504 All of Us participants from 33 states, and corresponding EHR data were available for 88,840 of these participants. The median and IQR of BMI taken from physical measurements data was 28.4 (24.4- 33.7) and 28.5 (24.5-33.6) from EHR data, where available. Overall obesity prevalence based on physical measurements data was 41.5% (95% CI, 41.3%-41.7%); prevalence of severe obesity was 20.7% (95% CI, 20.6-20.9), with large geographic variations observed across states. Prevalence estimates from states with greater numbers of All of Us participants were more similar to national population-based estimates than states with fewer participants.

CONCLUSION

All of Us participants had a high prevalence of obesity, with state-level geographic variation mirroring national trends. The diversity among All of Us participants may support future investigations on obesity prevention and treatment in diverse populations.

Pediatric data from the All of Us research program: demonstration of pediatric obesity over time

OBJECTIVE

To describe and demonstrate use of pediatric data collected by the All of Us Research Program.

MATERIALS AND METHODS

All of Us participant physical measurements and electronic health record (EHR) data were analyzed including investigation of trends in childhood obesity and correlation with adult body mass index (BMI).

RESULTS

We identified 19 729 participants with legacy pediatric EHR data including diagnoses, prescriptions, visits, procedures, and measurements gathered since 1980. We found an increase in pediatric obesity diagnosis over time that correlates with BMI measurements recorded in participants' adult EHRs and those physical measurements taken at enrollment in the research program.

DISCUSSION

We highlight the availability of retrospective pediatric EHR data for nearly 20 000 All of Us participants. These data are relevant to current issues such as the rise in pediatric obesity.

CONCLUSION

All of Us contains a rich resource of retrospective pediatric EHR data to accelerate pediatric research studies.

Predictive Analytics for Glaucoma Using Data From the All of Us Research Program

PURPOSE

To (1) use All of Us (AoU) data to validate a previously published single-center model predicting the need for surgery among individuals with glaucoma, (2) train new models using AoU data, and (3) share insights regarding this novel data source for ophthalmic research.

DESIGN

Development and evaluation of machine learning models.

METHODS

Electronic health record data were extracted from AoU for 1,231 adults diagnosed with primary open-angle glaucoma. The single-center model was applied to AoU data for external validation. AoU data were then used to train new models for predicting the need for glaucoma surgery using multivariable logistic regression, artificial neural networks, and random forests. Five-fold cross-validation was performed. Model performance was evaluated based on area under the receiver operating characteristic curve (AUC), accuracy, precision, and recall.

RESULTS

The mean (standard deviation) age of the AoU cohort was 69.1 (10.5) years, with 57.3% women and 33.5% black, significantly exceeding representation in the single-center cohort (P = .04 and P < .001, respectively). Of 1,231 participants, 286 (23.2%) needed glaucoma surgery. When applying the single-center model to AoU data, accuracy was 0.69 and AUC was only 0.49. Using AoU data to train new models resulted in superior performance: AUCs ranged from 0.80 (logistic regression) to 0.99 (random forests).

CONCLUSIONS

Models trained with national AoU data achieved superior performance compared with using single-center data. Although AoU does not currently include ophthalmic imaging, it offers several strengths over similar big-data sources such as claims data. AoU is a promising new data source for ophthalmic research.

Hypertension prevalence in the All of Us Research Program among groups traditionally underrepresented in medical research

The All of Us Research Program was designed to enable broad-based precision medicine research in a cohort of unprecedented scale and diversity. Hypertension (HTN) is a major public health concern. The validity of HTN data and definition of hypertension cases in the All of Us (AoU) Research Program for use in rule-based algorithms is unknown. In this cross-sectional, population-based study, we compare HTN prevalence in the AoU Research Program to HTN prevalence in the 2015-2016 National Health and Nutrition Examination Survey (NHANES). We used AoU baseline data from patient (age ≥ 18) measurements (PM), surveys, and electronic health record (EHR) blood pressure measurements. We retrospectively examined the prevalence of HTN in the EHR cohort using Systemized Nomenclature of Medicine (SNOMED) codes and blood pressure medications recorded in the EHR. We defined HTN as the participant having at least 2 HTN diagnosis/billing codes on separate dates in the EHR data AND at least one HTN medication. We calculated an age-standardized HTN prevalence according to the age distribution of the U.S. Census, using 3 groups (18-39, 40-59, and ≥ 60). Among the 185,770 participants enrolled in the AoU Cohort (mean age at enrollment = 51.2 years) available in a Researcher Workbench as of October 2019, EHR data was available for at least one SNOMED code from 112,805 participants, medications for 104,230 participants, and 103,490 participants had both medication and SNOMED data. The total number of persons with SNOMED codes on at least two distinct dates and at least one antihypertensive medication was 33,310 for a crude prevalence of HTN of 32.2%. AoU age-adjusted HTN prevalence was 27.9% using 3 groups compared to 29.6% in NHANES. The AoU cohort is a growing source of diverse longitudinal data to study hypertension nationwide and develop precision rule-based algorithms for use in hypertension treatment and prevention research. The prevalence of hypertension in this cohort is similar to that in prior population-based surveys.

Comparison of family health history in surveys vs electronic health record data mapped to the observational medical outcomes partnership data model in the All of Us Research Program

OBJECTIVE

Family health history is important to clinical care and precision medicine. Prior studies show gaps in data collected from patient surveys and electronic health records (EHRs). The All of Us Research Program collects family history from participants via surveys and EHRs. This Demonstration Project aims to evaluate availability of family health history information within the publicly available data from All of Us and to characterize the data from both sources.

MATERIALS AND METHODS

Surveys were completed by participants on an electronic portal. EHR data was mapped to the Observational Medical Outcomes Partnership data model. We used descriptive statistics to perform exploratory analysis of the data, including evaluating a list of medically actionable genetic disorders. We performed a subanalysis on participants who had both survey and EHR data.

RESULTS

There were 54 872 participants with family history data. Of those, 26% had EHR data only, 63% had survey only, and 10.5% had data from both sources. There were 35 217 participants with reported family history of a medically actionable genetic disorder (9% from EHR only, 89% from surveys, and 2% from both). In the subanalysis, we found inconsistencies between the surveys and EHRs. More details came from surveys. When both mentioned a similar disease, the source of truth was unclear.

CONCLUSIONS

Compiling data from both surveys and EHR can provide a more comprehensive source for family health history, but informatics challenges and opportunities exist. Access to more complete understanding of a person's family health history may provide opportunities for precision medicine.

Suggestive synergy between genetic variants in TF and HFE as risk factors for Alzheimer's disease

Alzheimer's disease (AD) is a complex disease that is likely influenced by many genetic and environmental factors. Citing evidence that iron may play a role in AD pathology, Robson et al. [Robson et al. (2004); J Med Genet 41:261-265] reported that epistatic interaction between rs1049296 (P589S) in the transferrin gene (TF) and rs1800562 (C282Y) in the hemochromatosis gene (HFE) results in significant association with risk for AD. In this study we attempted to replicate their findings in a total of 1,166 cases and 1,404 controls from three European and European American populations. Allele and genotype frequencies were consistent across the three populations. Using synergy factor analysis (SFA) and Logistic Regression analysis we tested each population and the combined sample for interactions between these two SNPs and risk for AD. We observed significant association between bi-carriers of the minor alleles of rs1049296 and rs1800562 in the combined sample using SFA (P = 0.0016, synergy factor = 2.71) and adjusted SFA adjusting for age and presence of the APOE epsilon 4 allele (P = 0.002, OR = 2.4). These results validate those of the previous report and support the hypothesis that iron transport and regulation play a role in AD pathology.

Immunolocalization of inhibin and activin alpha and betaB subunits and expression of corresponding messenger RNAs in the human adult testis

Inhibin B is a testicular peptide hormone that regulates FSH secretion in a negative feedback loop. Inhibin B is a dimer of an alpha and a beta(B) subunit. In adult testes, the cellular site of production is still controversial, and it was hypothesized that germ cells contribute to inhibin B production. To determine which cell types in the testes may produce inhibin B, the immunohistochemical localization of the two subunits of inhibin B were examined in adult testicular biopsies with normal spermatogenesis, spermatogenic arrest, or Sertoli cell only (SCO) tubules. Moreover, using in situ hybridization with mRNA probes, the mRNA expression patterns of inhibin alpha and inhibin/activin beta(B) subunits have been investigated. In all testes, Sertoli cells and Leydig cells showed positive immunostaining for inhibin alpha subunit and expressed inhibin alpha subunit mRNA. Using inhibin beta(B) subunit immunoserum on testes with normal spermatogenesis and with spermatogenic arrest, intense labeling was located in germ cells from pachytene spermatocytes to round spermatids but not in Sertoli cells. Inhibin beta(B) subunit mRNA expression was intense in germ cells from spermatogonia to round spermatids and in Sertoli cells in these testes. In testes with SCO, high inhibin beta(B) subunit mRNA labeling density was observed in both Sertoli cells and Leydig cells, whereas beta(B) subunit immunostaining was negative for Sertoli cells and faintly positive for Leydig cells. These results agree with the recent opinion that inhibin B in adult men is possibly a joint product of Sertoli cells and germ cells.

Increase of arterial thrombosis parameters in chronic Helicobacter pylori infection in mice

An animal model was developed to study arterial thrombosis and determine if animals infected with Helicobacter pylori behave differently after induction of direct damage to blood vessels. Twenty-one C56/BL6 mice inoculated with the "Sydney strain" of H. pylori and 19 uninfected animals were kept for 1 year before testing. Vascular lesions were induced to mesenteric arterioles (15-25 microm diameter) by Argon laser. The dynamic course of thrombus formation was continuously monitored by a video camera for 10 min. Three parameters were assessed: (1) the number of laser pulses required to induce thrombus formation, (2) the number of platelet emboli removed by the blood flow and, (3) the duration of embolization. Additionally, blood was tested for platelet aggregation, fibrinogen, and cell count. Of the parameters measured, statistical differences between infected and uninfected mice concerned the number of emboli formed (6.00+/-2.18 infected vs. 3.89+/-1.37 non-infected, p=.0006) and the duration of embolization (2.41+/-0.73 min infected vs. 1.47+/-0.61 min non-infected p>.0001). A significant difference was also found in the fibrinogen levels between infected and uninfected mice. Chronic infection of mice with H. pylori leads to increased platelet embolization after damage to arterioles. These results are in favor of the possible involvement of H. pylori infection in the acute phase of coronary heart disease (CHD).

Three-dimensional organization of retroviral capsid proteins on a lipid monolayer

We have used a method for the two-dimensional crystallization of retroviral structural proteins to obtain a three-dimensional structure of negatively stained, membrane-bound, histidine-tagged Moloney murine leukemia virus (M-MuLV) capsid protein (his-MoCA) arrays. Tilted and untilted micrographs from crystals formed by purified his-MoCA proteins incubated beneath lipid monolayers containing nickel-chelating lipids were used in 3D reconstructions. The 2D crystals had unit cell dimensions of a=72.6 A, b=72.5 A and gamma=119.5 degrees, but appeared to have no intrinsic symmetry (p1) in 3D, in contrast to the trigonal or hexagonal appearance of their 2D projections. Membrane-bound his-MoCA proteins showed a strand-like organization, apparently with dimer building blocks. Membrane-proximal regions, or putative N-terminal domains (NTDs), dimerized with different partners than the membrane-distal putative C-terminal domains (CTDs). Evidence also suggests that CTDs can adopt alternate orientations relative to their NTDs, forming interstrand connections. Our results are consistent with helical-spiral models for retrovirus particle assembly, but are not easily reconcilable with icosahedral models.

Cytoskeletal rearrangements induced by Helicobacter pylori strains in epithelial cell culture: possible role of the cytotoxin

The relationship between Helicobacter pylori adherence, cytotoxin production, and modification of the cytoskeletal structure was investigated by studying the effects of 12 H. pylori strains cocultured with Hep-2 epithelial cells. Bacterial strains were isolated from patients with peptic ulcer disease or nonulcer dyspepsia. Presence of the cag pathogenicity island and vacA subtypes of the strains were determined as was the production of vacuolating cytotoxin. We found that cytoskeletal rearrangements, as observed by confocal microscopy after double staining of the bacteria and the cell actin with Texas red and fluorescein-conjugated phalloidin, respectively, occurred essentially when the strains were cytotoxin producers and that the supernatants alone could also lead to these modifications.

Positive effect of rebamipide on gastric permeability in mice after eradication of Helicobacter felis

BACKGROUND

Despite Helicobacter pylori eradication, gastric inflammation persists for months or years. Preliminary results have indicated that an increase in gastric permeability could be one reason. Our aim was to evaluate the effect of a mucosal protective drug, rebamipide, on gastric permeability in a model of H. felis-infected mice.

METHODS

Thirty-three C57/BL6 mice were inoculated with H. felis, and seven controls were kept non-inoculated. After 2 months 20 infected mice were treated with omeprazole, amoxicillin, and clarithromycin for 1 week and then for 4 weeks with either rebamipide (n = 9) or placebo (n = 11). The 13 remaining mice were kept untreated. After cessation of treatment, a fragment of antrum obtained from each mouse was mounted in a small Ussing chamber to study the electric resistance of the tissue (R) and antral permeability.

RESULTS

No modification of the paracellular permeability (R, JNa, JMan) was observed in either group. However, the transcellular permeability to horseradish peroxidase (HRP) was significantly increased in H. felis-infected non-treated mice (1131 +/- 463, 948 +/- 339, and 182 +/- 312 ng/h x cm2) as compared with non-infected controls (469 +/- 262, 458 +/- 261, and 10 +/- 6 ng/ h x cm2, for J3H-HRP, JD, and JHRPi, respectively) (P < 0.003). Eradication of the bacteria by antibiotics without subsequent treatment with rebamipide led to a non-significant decrease in the HRP fluxes. However, when rebamipide was used after the antibiotic treatment, a significant (P < 0.01) decrease in HRP fluxes as compared with non-treated mice was observed.

CONCLUSIONS

These results confirm that gastric permeability to macromolecules remains increased despite H. felis eradication and show that rebamipide can facilitate the normalization of gastric permeability to macromolecules after bacterial eradication.

Measuring physical activity in midlife, older, and minority women: issues from an expert panel

This article summarizes the findings of an exploratory meeting of 53 experts brought together under the aegis of the Women's Health Initiative to identify important issues related to measuring physical activity in minority women, women in midlife (aged 40-75), and older women (aged > 75). The findings address five areas, three dealing with measurement and two concerning the design of surveys: (1) population characteristics to consider when measuring the physical activity of women and minority populations, (2) activity dimensions relevant to physical activity surveys, (3) measuring moderate and intermittent activities, (4) designing and administering physical activity surveys for older and minority women, and (5) establishing the reliability and validity of such physical activity surveys. Although the focus of the expert panel meeting was on identifying issues related to the measurement of physical activity in women, many issues summarized here can be generalized to children and men. The panel's findings concerning measuring physical activity are timely, as they directly bear on the challenges associated with the physical activity guidelines jointly issued by the Centers for Disease Control and Prevention and the American College of Sports Medicine and the recommendations made in the Surgeon General's 1996 report, Physical Activity and Health.

Heterogeneity of immunoglobulin G response to Helicobacter pylori measured by the unweighted pair group method with averages

The heterogeneity of the immune response to Helicobacter pylori has always been noticed but has never been evaluated by obtaining a quantitative measure. For this purpose, sera were tested by enzyme-linked immunosorbent assay, and 207 positive serum specimens were subsequently tested by immunoblotting. The presence or absence of six specific bands was noted. The homology of the different profiles of bands was measured by calculating the Dice coefficient, and a dendrogram was constructed. Thirty-four profiles were found, with each profile containing from 1 to 43 serum specimens. At a level of 72% similarity, 115 of the serum specimens studied fell into eight profiles. At a level of 48% similarity, 186 of the serum specimens studied fell into 22 profiles. The difference in immunoblot profiles was probably linked to the host immune response, but infection with strains carrying different antigens cannot be ruled out.

Association of CagA-positive and CagA-negative Helicobacter pylori strains with patients' symptoms and gastritis in primary care patients with functional upper abdominal complaints

BACKGROUND

CagA-positive Helicobacter pylori strains have been reported to be associated with peptic ulcer or malignancy more often than cagA-negative strains. Less is known about the relation of H. pylori serology (CagA-negative or CagA-positive) to histologic changes in the stomach of patients with functional upper abdominal complaints. The association of H. pylori status with patient symptoms or with different subgroups of non-organic dyspepsia is also obscure. In the present study patients' symptoms and their relation to H. pylori serology (H. pylori-negative, H. pylori-positive but CagA-negative, and H. pylori-positive and CagA-positive) were evaluated in general practice patients who had functional upper abdominal complaints. The association of H. pylori serology with different symptom-based subgroups of functional upper abdominal complaints was also assessed. The severity and activity of inflammation and the presence of atrophy and intestinal metaplasia in the antrum and body were evaluated and compared with H. pylori status.

METHODS

Four hundred consecutive unselected dyspeptic patients in primary care were investigated by means of gastroscopy, upper abdominal ultrasound, laboratory screening including H. pylori and CagA serology, and other examinations if needed. Of these patients 193 with functional upper abdominal complaints were enrolled in this study.

RESULTS

Of the study patients 87 (45%) were H. pylori-negative, 70 (36%) were H. pylori- and CagA-positive, and 36 (19%) were H. pylori-positive but CagA-negative. There were no differences in the occurrence of any dyspeptic symptoms between H. pylori-related subgroups. Nor was there an association between H. pylori status and symptom-based subgroups in our study patients. Inflammation of the stomach was related to H. pylori infection, but CagA-seropositive patients did not have moderate or severe inflammation more often than CagA-seronegative ones. CagA-seropositive patients with functional upper abdominal complaints did not have atrophic changes or intestinal metaplasia in the stomach more often than those who were CagA-negative.

CONCLUSIONS

H. pylori or more specific CagA serology is not associated with any specific symptom profile of dyspepsia or with any symptom-based subgroups in patients with functional upper abdominal complaints in primary care. The study patients with CagA seropositivity did not have more severe histologic changes in the stomach than the patients who were H. pylori-seropositive but CagA-seronegative.

Usefulness of anti-Helicobacter pylori and anti-CagA antibodies in the selection of patients for gastroscopy

OBJECTIVES

Screening of dyspeptic patients with serological tests for Helicobacter pylori before open-access gastroscopy has been suggested to be worthwhile. CagA-positive H. pylori strains may be associated with major pathology more often than CagA-negative strains. The usefulness of anti-H. pylori and anti-CagA antibodies in screening for gastroscopy was evaluated in unselected dyspeptic patients.

METHODS

Four hundred consecutive, unselected dyspeptic patients (mean age, 56.8 yr) in primary care were investigated with gastroscopy, ultrasonography of the upper abdomen, laboratory tests (including serological tests for H. pylori and CagA), and other examinations if needed. The patients were followed for 1 yr.

RESULTS

Results of serological tests were positive for H. pylori in 56.2% of patients, of whom 64.4% also had results positive for CagA. Use of H. pylori and CagA serology-based screening combined with a history of nonsteroidal anti-inflammatory drug use would have detected only 80 and 70% of the major pathologies (peptic ulcer, moderate or severe esophagitis, celiac disease, or malignancy), respectively, in these patients. Gastroscopy would have been avoided in 30 and 41%, respectively, if only patients who had positive results on serological tests or who were nonsteroidal anti-inflammatory drug users would have been referred. In patients younger than 45 yr of age (n = 87), 60-74% of gastroscopies would have been avoided, but 50-60% of major pathologies would have been missed, by using the screening strategy studied. One of the nine malignancies (all in patients >45 yr of age) was H. pylori-negative, and two were CagA-negative.

CONCLUSIONS

Anti-CagA antibodies do not offer advantages compared with anti-H. pylori antibodies in screening patients for gastroscopy. A remarkable share of major pathologies are missed by both of these screening methods. Therefore, the results of these screening tests are not recommended as selective criteria for gastroscopy.

Exploring the use of explanatory models in nursing research and practice

PURPOSE

To address the lack of information in nursing for delivering culturally appropriate care and provide a framework for nurses to incorporate diverse beliefs and health needs into research and practice. People interpret and react to health and illness events within a cultural system. However, the nursing literature contains little about how to elicit cultural beliefs.

ORGANIZING FRAMEWORK

Use of Kleinman's (1980) concept of explanatory models (EMs) is explored first, by describing the concept as it was developed by Kleinman, and second, by illustrating how it was used in three research studies conducted between 1990 and 1994.

METHOD

Individual in-depth interviews were conducted with community-based convenience samples. Data were analyzed using content analysis. Explanatory models were explored with health people following illness, and with people having a condition with potential health risks, to illustrate their usefulness in nursing research and practice.

CONCLUSIONS

The findings provide a beginning understanding of the complex linkages between beliefs and actions and demonstrate the versatility and usefulness of EMs for nursing research and practice. Assessing models offers one means for researchers and clinicians to explore health beliefs and the linkages between beliefs and behaviors.

Helicobacter pylori-human polymorphonuclear leucocyte interaction in the presence of ammonia

OBJECTIVE

To determine if the ammonia produced by Helicobacter pylori affects the phagocytic ability of human polymorphonuclear leucocytes as measured by the oxidative burst.

METHODS

Interactions between opsonized urease-positive and -negative strains of H. pylori with polymorphonuclear leucocytes were studied in two series of experiments. In the first series of experiments, concentrations from 0 to 50 mM of NH4Cl were added to polymorphonuclear leucocytes. In the second series of experiments, bacteria were pre-incubated for 1 h with urea (0 to 50 mM) before addition of phagocytes. Luminol-dependent chemiluminescence was measured every 5 min over a 50-min period. The pH was verified in each treatment.

RESULTS

Inhibition of chemiluminescence, increasing with concentration, was noted in all treatments when NH4Cl was added. When urea was added to urease-positive strains, chemiluminescence was significantly reduced when compared to the urease-negative strain and the zymosan control. This effect could not be attributed to a change in pH in the experiments using NH4Cl or urea at a concentration of 5 mM and 10 mM.

CONCLUSION

Ammonia generated by H. pylori may contribute to the decreased activity of polymorphonuclear leucocytes in vivo.

Community collaboration: prevention and control of tuberculosis in a homeless shelter

An urban shelter in Charleston, South Carolina developed and began a tuberculosis (TB) prevention and control plan that addressed the priorities recommended by the Centers for Disease Control and Prevention. After an increase in TB in the shelter in 1992, the local health department, the homeless clinic nurse practitioners, and Medical University of South Carolina College of Nursing faculty and students collaborated with the shelter staff to provide initial mass screenings for contact investigation. They also developed and implemented new policies and procedures for an ongoing TB prevention and control program. The new policies required that guests obtain screening for TB within 7 days of arrival at the shelter and every 6 months thereafter. Also, a public health nurse began providing directly observed therapy twice weekly at the shelter. Of the initial 22 persons who started TB preventive therapy in 1993, 17 (77%) completed therapy. The clinic nurse practitioners, nursing students, and public health nurses had important and defined roles in the mass-screening process, case identification and treatment, policy development and implementation, health education, and establishing methods of communication between the shelter, clinic, and health department. An ongoing health care community collaborative effort may successfully reduce tuberculosis disease in a homeless shelter population.

Social responsibility in nursing education

Nurses will be key participants in health care reform as health care shifts from a hospital-based disease orientation to a community-centered health promotion focus. Nursing in communities, the environmental context of clients' everyday lives, requires attention to social, economic, and political circumstances that influence health status and access to health care. Therefore, nursing educators have the responsibility to prepare future nurses for community-based practice by instilling moral and professional practice obligations, cultural sensitivity, and other facets of social responsibility. In this article, social responsibility and journaling, a teaching/learning strategy suggested by the new paradigm approach of the curriculum revolution, are explored. A qualitative research study of more than 100 nursing student journal entries illustrates the concept of social responsibility and how it developed in a group of baccalaureate nursing students during a clinical practicum in a large urban homeless shelter.

A population based study of Helicobacter pylori infection in a European country: the San Marino Study. Relations with gastrointestinal diseases

Helicobacter pylori is present worldwide but few large population studies exist on the epidemiology of the infection. A random cross sectional study was performed of H pylori infection in the adult population of San Marino, a European country with high gastric cancer rate, to assess its prevalence and to evaluate its relations with gastrointestinal disease. In 2237 subjects (77% of the initial sample) H pylori IgG antibodies were detected with enzyme linked immunosorbent assay (ELISA) and immunoblotting. A questionnaire including questions about occupation, place of birth, and smoking was given to all subjects. Dyspepsia, peptic ulcer, and gastric cancer in the subjects, relatives, and partners as well as use of drug, dental treatment/prostheses, and gastrointestinal endoscopies, were evaluated by multivariate analysis. H pylori prevalence was of 51%, increased with age from 23% (20-29 years) to 68% (> or = 70 years), and was higher among manual workers. H pylori was independently associated with ulcer (OR = 1.63, 95% confidence intervals (CI) = 1.16 to 2.27), H2 antagonists (OR = 1.94, 95% CI = 1.21 to 3.10), and benzodiazepines (OR = 1.57, 95% CI = 1.02 to 2.42), dental prostheses (OR = 1.25, 95% CI = 1.05 to 1.49), gastroscopy in the past five years (OR = 1.50, 95% CI = 1.05 to 2.14), peptic ulcer in siblings (OR = 1.52, 95% CI = 1.09 to 2.12), gastric cancer in father (OR = 1.61, 95% CI = 1.02 to 2.52). The association of seropositivity with history of ulcer, gastric cancer in family, gastroscopy, and H2 antagonists suggests that H pylori is an epidemiological key factor in the pathogenesis of gastroduodenal diseases in this area.

Body size values of white and black women

The purpose of this naturalistic study was to compare values held by 36 white and 31 black women related to body size, and to identify factors that influence these values and linkages between body size values and weight management activities. Black women of lower SES were significantly different from black women of higher SES and white women, regardless of SES, in that they were heavier, viewed themselves as heavier, and perceived attractive body size as heavier. Black lower status women had to become a great deal heavier than the other groups before they defined themselves as overweight. We suggest that black lower social status women have a wider range of "normal" and attractive body size and that this wider range is developed from comparisons of other women in their social milieu and influences the initiation of weight loss activities.

The cohort effect and Helicobacter pylori

A total of 631 serum samples collected in 1969, 1979, and 1989 from adults and children were screened for Helicobacter pylori by Western blot analysis. Results showed that H. pylori seroprevalence has become less frequent over the 20-year period. By studying seropositivity by year of birth, the magnitude of a cohort effect of H. pylori seropositivity was estimated. The odds of being seropositive decreased by 26% per decade, P = .008 (95% confidence interval, 8%-41%). Estimates of seroprevalence adjusted for both age-specific variation and the cohort effect suggest that most seropositivity in adults occurs by the age of 15 years. The implication of these findings is that H. pylori infection is becoming less frequent and is predominantly acquired in childhood.

Measles virus-specific cellular immunity in patients with vaccine failure

The cytotoxic T-lymphocyte (CTL) response to measles virus (MV) was studied in blood samples from 13 acute- and early convalescent-phase patients with measles infection despite previous vaccination with the live-MV vaccine. MV CTL responses were also measured in six healthy peer controls who had live-MV vaccination during childhood and in five healthy adults who had a remote history of natural measles. All patients recovered from illness without complication. Acute MV infection was diagnosed on the basis of the Centers for Disease Control criteria and by measuring MV-specific immunoglobulin G (IgG) and IgM antibodies. Elevated IgG titers occurred in 80% of the patients at 1 to 2 weeks and in 100% at 4 weeks postinfection. IgM antibodies were detectable in all patient tested and were elevated in 60% of the patients at 1 to 2 weeks postinfection. The MV-specific CTL response was enhanced in 10 of the 13 patients tested, with a mean maximal lysis of 48.5% +/- 13.3%, compared with that of healthy peer controls who had had live-MV vaccinations during childhood (mean lysis, 14.6% +/- 12.9%; n = 6) and healthy adults with a remote history of natural measles (mean, 30.8% +/- 12.2%; n = 5). Three patients had low MV CTL levels at two time points following measles, with a mean lysis of 12% +/- 1.7%. It is concluded that while there is no evidence for a deficiency in the generation of cellular immunity to MV in the majority of patients with MV vaccine failure, a small number of individuals may fail to develop an enhanced T-cell response following infection.

cis and trans regulation of tissue-specific transcription

Analysis of both the cis-regulatory sequences which control globin gene switching as well as the trans-acting factors which bind to these sequences to elicit a differential, developmentally regulated response has lent insight into the general mechanisms responsible for tissue-specific gene regulation. We show here that the chicken adult beta-globin gene promoter sequences are intimately involved in competitive interaction with the beta/epsilon-globin enhancer to regulate differentially epsilon- versus beta-globin gene transcription. Secondly, we show that the family of GATA transcription factors directs gene regulation in a variety of discrete cell types, and describe potential cellular target genes for each member of the GATA factor family, as well as potential mechanisms whereby multiple GATA factors expressed in a single cell might be used to elicit differential transcriptional activities.

Transferrin- and albumin-directed expression of growth-related peptides in transgenic sheep

Chimeric genes containing either the mouse transferrin (Trf) enhancer/promoter fused to the structural sequences encoding bovine growth hormone (GH) or the mouse albumin (Alb) enhancer/promoter fused to the gene for human growth hormone-releasing factor (GRF) were microinjected into sheep zygotes. A low percentage of resulting transgenic sheep chronically expressed the respective genes, resulting in elevated plasma concentrations of circulating GH or GRF, respectively. Growth hormone-releasing factor expression induced elevated plasma levels of endogenous GH production. In addition, elevated levels of circulating insulin-like growth factor-I were observed in the bovine GH-expressing Trf transgenic sheep. Growth of these founder transgenic sheep relative to controls were not enhanced. In part, this may be due to the development of the diabetic condition exhibited by both transgenic groups. These results demonstrate that the mouse Trf and Alb enhancer/promoters are active in sheep and suggest that alternate strategies for expressing growth-related genes may be required to modulate growth in sheep.

[Thromboxane A2 and granulocyte elastase after severe trauma--relationship to complications and survival rates]

Of 64 polytraumatized patients with a mean injury severity score of 33.1, 42 showed marked systemic release of thromboxane B2 and granulocyte elastase during the initial 18 hours after trauma, reaching peak arterial levels of greater than 1,000 pg/ml and ng/ml, respectively. If those patients ("responders": plasma TXB2 greater than 250 pg/ml) were compared with the remaining 22 ("non-responders": TXB2 less than 250 pg/ml) the following became obvious: "Late" mortality (greater than 3 d) was 31% in responders, which is significantly higher than in non-responders (9%). No correlation was observed between "early" mortality (less than 3 d) and mediator release. There was no difference in the incidence of the adult respiratory distress syndrome (ARDS) (38% versus 32%) or the late sepsis syndrome (17% versus 18%) between responders and non-responders. Morbidity, however, differed markedly in that ARDS in responders was associated with significantly higher elastase levels, a higher mortality and 10 times higher incidence of sepsis as compared to responders without ARDS. ARDS in non-responders, by contrast, did not change elastase maxima or the mortality rate as compared to non-responders without ARDS. It is concluded that TXB2 is not a predictor of posttraumatic ARDS, but is related to a complicated course, in particular to sepsis and mortality. Elastase with high probability predicts ARDS and/or the late sepsis syndrome. Simultaneous determination of TXB2 further enhances the predictive value of elastase.

Persistent cemento-ossifying fibroma of the mandible: report of a case and review of literature

This case report describes an unusual recurrence of a cemento-ossifying fibroma and illustrates the diagnostic difficulties that may be encountered when treating fibro-osseous lesions.

Growth hormone releasing hormone and growth hormone: genetic studies in familial growth hormone deficiency

Four families with growth hormone (GH) deficiency, either isolated or with other pituitary hormonal deficits are described. Members of each underwent pharmacological testing for GH secretion and infusions of GH releasing hormone (GHRH) to determine the locus of the defect in GH secretion. In addition, we have extracted DNA from white blood cells to characterize the GHRH and GH genes. All members tested had the normal complement of GH and GHRH genes. Four generations of one family with isolated GH deficiency, autosomal dominant were studied. The younger members showed minimal GH responsiveness to a single infusion of GHRH. However, the older members did not respond even after 30 doses of GHRH given intravenously every 3 h. Two members of a family with the autosomal recessive type of isolated GH deficiency had large GH increases after GHRH infusion. Thus in these families the GH secretory defect lies within the hypothalamus. Members of two families with pituitary deficiency (GH and other tropic hormones) of the autosomal recessive type had variable responses to GHRH and varying amounts of pituitary tissue seen on high resolution CT scans. Although it is not possible to delineate the precise location of the secretory defects in these latter two families, a hypothalamic defect is probable based on the responses to multiple trophic stimuli. Heterogeneity of structure and function exists within and between families with isolated GH deficiency and within and among families with pituitary deficiency. It is from the study of such families in which all members presumably have the same underlying defect that one can more readily decide on a pathogenetic mechanism.