Publications

Zinc-finger nucleases (ZFNs) allow targeted gene inactivation in a wide range of model organisms. However, construction of target-specific ZFNs is technically challenging. Here, we evaluate a straightforward modular assembly-based approach for ZFN construction and gene inactivation in zebrafish. From an archive of 27 different zinc-finger modules, we assembled more than 70 different zinc-finger cassettes and evaluated their specificity using a bacterial one-hybrid assay. In parallel, we constructed ZFNs from these cassettes and tested their ability to induce lesions in zebrafish embryos. We found that the majority of zinc-finger proteins assembled from these modules have favorable specificities and nearly one-third of modular ZFNs generated lesions at their targets in the zebrafish genome. To facilitate the application of ZFNs within the zebrafish community we constructed a public database of sites in the zebrafish genome that can be targeted using this archive. Importantly, we generated new germline mutations in eight different genes, confirming that this is a viable platform for heritable gene inactivation in vertebrates. Characterization of one of these mutants, gata2a, revealed an unexpected role for this transcription factor in vascular development. This work provides a resource to allow targeted germline gene inactivation in zebrafish and highlights the benefit of a definitive reverse genetic strategy to reveal gene function.

BACKGROUND

Studies suggest that advancing age is an independent risk factor for experiencing adverse events during colonoscopy. Yet many of these studies are limited by small sample sizes and/or marked variation in reported outcomes.

OBJECTIVE

To determine the incidence rates for specific adverse events in elderly patients undergoing colonoscopy and calculate incidence rate ratios for selected comparison groups.

SETTING AND PATIENTS

Elderly patients undergoing colonoscopy.

DESIGN

Systematic review and meta-analysis.

MAIN OUTCOME MEASUREMENTS

Perforation, bleeding, cardiovascular (CV)/pulmonary complications, and mortality.

RESULTS

Our literature search yielded 3328 articles, of which 20 studies met our inclusion criteria. Pooled incidence rates for adverse events (per 1000 colonoscopies) in patients 65 years of age and older were 26.0 (95% CI, 25.0-27.0) for cumulative GI adverse events, 1.0 (95% CI, 0.9-1.5) for perforation, 6.3 (95% CI, 5.7-7.0) for GI bleeding, 19.1 (95% CI, 18.0-20.3) for CV/pulmonary complications, and 1.0 (95% CI, 0.7-2.2) for mortality. Among octogenarians, adverse events (per 1000 colonoscopies) were as follows: cumulative GI adverse event rate of 34.9 (95% CI, 31.9-38.0), perforation rate of 1.5 (95% CI, 1.1-1.9), GI bleeding rate of 2.4 (95% CI, 1.1-4.6), CV/pulmonary complication rate of 28.9 (95% CI, 26.2-31.8), and mortality rate of 0.5 (95% CI, 0.06-1.9). Patients 80 years of age and older experienced higher rates of cumulative GI adverse events (incidence rate ratio 1.7; 95% CI, 1.5-1.9) and had a greater risk of perforation (incidence rate ratio 1.6, 95% CI, 1.2-2.1) compared with younger patients (younger than 80 years of age). There was an increased trend toward higher rates of GI bleeding and CV/pulmonary complications in octogenarians but neither was statistically significant.

LIMITATIONS

Heterogeneity of studies included and not all complications related to colonoscopy were captured.

CONCLUSIONS

Elderly patients, especially octogenarians, appear to have a higher risk of complications during and after colonoscopy. These data should inform clinical decision making, the consent process, public health policy, and comparative effectiveness analyses.

Food insecurity has been linked to high-risk sexual behavior in sub-Saharan Africa, but there are limited data on these links among people living with HIV/AIDS, and on the mechanisms for how food insecurity predisposes individuals to risky sexual practices. We undertook a series of in-depth open-ended interviews with 41 individuals living with HIV/AIDS to understand the impact of food insecurity on sexual-risk behaviors. Participants were recruited from the Immune Suppression Clinic at the Mbarara University of Science and Technology in Mbarara, Uganda. Interviews were recorded, transcribed verbatim, translated, and coded following the strategy of grounded theory. Four major themes emerged from the interview data: the relationship between food insecurity and transactional sex for women; the impact of a husband's death from HIV on worsening food insecurity among women and children; the impact of food insecurity on control over condom use, and the relationship between food insecurity and staying in violent/abusive relationships. Food insecurity led to increased sexual vulnerability among women. Women were often compelled to engage in transactional sex or remain in violent or abusive relationships due to their reliance on men in their communities to provide food for themselves and their children. There is an urgent need to prioritize food security programs for women living with HIV/AIDS and address broader gender-based inequities that are propelling women to engage in risky sexual behaviors based on hunger. Such interventions will play an important role in improving the health and well-being of people living with HIV/AIDS, and preventing HIV transmission.

Hematologic changes in acute and convalescent uncomplicated Plasmodium falciparum malaria have not been well studied, particularly in young children in Africa. Hematologic data were obtained for 3,044 children less than five years of age in seven randomized controlled trials at 14 sites. Using paired analysis between day 28 and baseline in patients without parasitologic failure as a proxy for malaria-induced effects, we found a statistically significant but clinically modest increase in leukocyte counts (5%) resulting from a larger increase in neutrophils (43%) than the decrease in lymphocytes counts (-16%); levels of hemoglobin and platelets decreased (-13% and -49%, respectively). Multivariate random effects analysis showed trends during follow-up (increased levels of hemoglobin, platelets and lymphocytes, and decreased levels of leukocytes and neutrophils) and identified explanatory variables. The risk of neutropenia increased with follow-up time independent of treatment outcome, and was lower with age, higher baseline parasitemia, and artemisinin combination treatment. These analyses provides information on hematologic variations caused by malaria.

Recent advances in understanding the epidemiology, genetics, diagnosis, clinical presentations, skeletal involvement, and therapeutic approaches to hypoparathyroidism led to the First International Workshop on Hypoparathyroidism that was held in 2009. At this conference, a group of experts convened to discuss these issues with a view towards a future research agenda for this disease. This review, which focuses primarily on hypoparathyroidism in the adult, provides a comprehensive summary of the latest information on this disease.

OBJECTIVE

Obesity is associated with high rates of disability in the general population. The nature of the relationship between obesity and disability in systemic lupus erythematosus (SLE), a condition with a high background rate of disability, is unknown.

METHODS

Data were from 2 interviews, 4 years apart, of a longitudinal cohort of individuals with SLE (n = 716 women). Body mass index (BMI) was calculated from self-reported height and weight; obesity was classified by usual (BMI ≥30) and revised (BMI ≥26.8) definitions. Three measures of functioning were examined: the Short Form 36 (SF-36) Health Survey physical function (PF) subscale, Valued Life Activities (VLA) Disability Questionnaire, and employment. Multivariate analyses controlled for demographics, SLE duration and disease activity, glucocorticoid use, depression, and comorbidities. Prospective analyses also controlled for baseline function.

RESULTS

At a BMI of ≥30, 27.8% of the subjects were obese; at a BMI of ≥26.8, 40.6% of the subjects were obese. Regardless of obesity definition, obese women exhibited poorer baseline function, with decrements ranging from 20-33% depending on the functional measure and obesity definition. With a BMI of ≥26.8, the adjusted SF-36 PF scores were 4.3 points lower for obese women (P < 0.0001), VLA difficulty was 0.09 higher (P = 0.01), and odds of employment were 80% of nonobese women (odds ratio 0.8, 95% confidence interval 0.5-1.1). At the 4-year followup, women who were obese at baseline had poorer function and experienced greater functional declines.

CONCLUSION

Obesity was associated with clinically significant negative effects on function, both concurrently and prospectively. This negative impact occurred at a lower BMI than is often considered problematic clinically. Because of the high rate of SLE-related disability, addressing preventable risk factors such as obesity may improve long-term SLE outcomes.

In Israel, Yemenite Jews and other populations including Ethiopian Jews and Bedouins have a low neutrophil count. This phenomenon has been called "benign neutropenia" since it has not been associated with any increased risk of infection and has also been described in other populations around the world including Africans, African Americans and Afro-Carribeans. Here we describe the recent success in mapping the gene that underlies benign neutropenia in African American populations. We discuss the known function of the gene and consider potential mechanisms for the effect on neutropenia. We also consider the possibility that this gene underlies the same effect observed in Yemenite Jews, Ethiopian Jews and Bedouins in Israel.

Scientific advances have improved our ability to target cancer interventions to individuals who will benefit most and spare the risks and costs to those who will derive little benefit or even be harmed. Several approaches are currently used for targeting interventions for cancer risk reduction, screening, and treatment, including risk prediction algorithms for identifying high-risk subgroups and diagnostic tests for tumor markers and germline genetic mutations. Economic evaluation can inform decisions about the use of targeted interventions, which may be more costly than traditional strategies. However, assessing the impact of a targeted intervention on costs and health outcomes requires explicit consideration of the method of targeting. In this study, we describe the importance of this principle by reviewing published cost-effectiveness analyses of targeted interventions in breast cancer. Few studies we identified explicitly evaluated the relationships among the method of targeting, the accuracy of the targeting test, and outcomes of the targeted intervention. Those that did found that characteristics of targeting tests had a substantial impact on outcomes. We posit that the method of targeting and the outcomes of a targeted intervention are inextricably linked and recommend that cost-effectiveness analyses of targeted interventions explicitly consider costs and outcomes of the method of targeting.