The National Children's Study Archive Model: A 3-Tier Framework for Dissemination of Data and Specimens for General Use and Secondary Analysis.

The National Children's Study (NCS) Archive was created as a repository of samples, data, and information from the NCS Vanguard Study-a longitudinal pregnancy and birth cohort evaluating approaches to study influence of environmental exposures on child health and development-to provide qualified researchers with access to NCS materials for use in secondary research. The National Children's Study Archive (NCSA) model is a 3-tiered access model designed to make the wealth of information and materials gathered during the NCS Vanguard Study available at a user appropriate level. The NCSA model was developed as a 3-tier framework, for users of varying access levels, providing intuitive data exploration and visualization tools, an end-to-end data and sample request management system, and a restricted portal for participant-level data access with a team of experts available to assist users. This platform provides a model to accelerate transformation of information and materials from existing studies into new scientific discoveries. Trial Registration: ClinicalTrials.gov Identifier: NCT00852904 (first posted February 27, 2009).

Smartphone-Enhanced Training, QA, Monitoring, and Evaluation of a Platform for Secondary Prevention of Cervical Cancer: Opportunities and Challenges to Implementation in Tanzania.

PURPOSE: Until human papillomavirus (HPV)-based cervical screening is more affordable and widely available, visual inspection with acetic acid (VIA) is recommended by the WHO for screening in lower-resource settings. Visual inspection will still be required to assess the cervix for women whose screening is positive for high-risk HPV. However, the quality of VIA can vary widely, and it is difficult to maintain a well-trained cadre of providers. We developed a smartphone-enhanced VIA platform (SEVIA) for real-time secure sharing of cervical images for remote supportive supervision, data monitoring, and evaluation. METHODS: We assessed programmatic outcomes so that findings could be translated into routine care in the Tanzania National Cervical Cancer Prevention Program. We compared VIA positivity rates (for HIV-positive and HIV-negative women) before and after implementation. We collected demographic, diagnostic, treatment, and loss-to-follow-up data. RESULTS: From July 2016 to June 2017, 10,545 women were screened using SEVIA at 24 health facilities across 5 regions of Tanzania. In the first 6 months of implementation, screening quality increased significantly from the baseline rate in the prior year, with a well-trained cadre of more than 50 health providers who "graduated" from the supportive-supervision training model. However, losses to follow-up for women referred for further evaluation or to a higher level of care were considerable. CONCLUSION: The SEVIA platform is a feasible, quality improvement, mobile health intervention that can be integrated into a national cervical screening program. Our model demonstrates potential for scalability. As HPV screening becomes more affordable, the platform can be used for visual assessment of the cervix to determine amenability for same-day ablative therapy and/or as a secondary triage step, if needed.

Long-Term Depuration of Crassostrea virginica Oysters at Different Salinities and Temperatures Changes Vibrio vulnificus Counts and Microbiological Profile.

Previous short-duration depuration studies with the eastern oyster ( Crassostrea virginica) demonstrated difficulty in achieving significant naturally incurred Vibrio vulnificus population count reductions. The present study used long-duration depuration (14 days) at controlled temperatures (10 or 22°C) and salinities (12, 16, or 20 mg/g). All depuration temperature-salinity combinations significantly reduced V. vulnificus counts, with greatest reductions seen in 12 mg/g, 10°C seawater (2.7-log CFU/g reduction) and in 20 mg/g, 22°C seawater (2.8-log reduction). Mesophilic vibrios dominated the overall microflora of freshly harvested oysters, whereas refrigerated storage selected for psychrotrophic bacteria ( Pseudomonas spp., Aeromonas spp., Shewanella spp., Psychrobacter spp.) as well as did depuration at 10°C ( Pseudoalteromonas spp., Shewanella spp., Vibrio spp.). Depuration at 22°C retained dominance of mesophilic vibrios, including pathogenic species, followed by Shewanella spp., Pseudoalteromonas spp., and Photobacterium spp. Although aerobic plate counts were lower in 22°C depurated oysters (5.0 log versus 6.0 log) compared with 10°C, depuration at 10°C offered greater V. vulnificus population reductions than depuration at 22°C. This advantage was only seen at 12 mg/g salinity, with no impact at 16 and 20 mg/g salinities. No depuration treatment reduced V. vulnificus counts to nondetectable levels. Use of prolonged depuration may be a helpful intervention to control V. vulnificus populations in oysters.

Comparison of Recruitment Strategy Outcomes in the National Children's Study.

BACKGROUND AND OBJECTIVES: In 2000, the US Congress authorized the National Institutes of Health to conduct a prospective national longitudinal study of environmental influences on children's health and development from birth through 21 years. Several recruitment methodologies were piloted to determine the optimal strategy for a main National Children's Study. METHODS: After an initial pilot recruitment that used a household enumeration strategy performed poorly, the National Children's Study Vanguard Study developed and evaluated the feasibility, acceptability, and cost of 4 alternate strategies to recruit a large prospective national probability sample of pregnant women and their newborn children. We compare household-based recruitment, provider-based recruitment, direct outreach, and provider-based sampling (PBS) strategies with respect to overall recruitment success, efficiency, cost, and fulfillment of scientific requirements. RESULTS: Although all 5 strategies achieved similar enrollment rates (63%-81%) among eligible women, PBS achieved the highest recruitment success as measured by the ratio of observed-to-expected newborn enrollees per year of 0.99, exceeding those of the other strategies (range: 0.35-0.48). Because PBS could reach the enrollment target through sampling of high volume obstetric provider offices and birth hospitals, it achieved the lowest ratio of women screened to women enrolled and was also the least costly strategy. With the exception of direct outreach, all strategies enrolled a cohort of women whose demographics were similar to county natality data. CONCLUSIONS: PBS demonstrated the optimal combination of recruitment success, efficiency, cost, and population representativeness and serves as a model for the assembly of future prospective probability-based birth cohorts.

Evaluation of a Smartphone-Based Training Strategy Among Health Care Workers Screening for Cervical Cancer in Northern Tanzania: The Kilimanjaro Method.

PURPOSE: Almost nine of 10 deaths resulting from cervical cancer occur in low-income countries. Visual inspection under acetic acid (VIA) is an evidence-based, cost-effective approach to cervical cancer screening (CCS), but challenges to effective implementation include health provider training costs, provider turnover, and skills retention. We hypothesized that a smartphone camera and use of cervical image transfer for real-time mentorship by experts located distantly across a closed user group through a commercially available smartphone application would be both feasible and effective in enhancing VIA skills among CCS providers in Tanzania. METHODS: We trained five nonphysician providers in semirural Tanzania to perform VIA enhanced by smartphone cervicography with real-time trainee support from regional experts. Deidentified images were sent through a free smartphone application on the available mobile telephone networks. Our primary outcomes were feasibility of using a smartphone camera to perform smartphone-enhanced VIA and level of agreement in diagnosis between the trainee and expert reviewer over time. RESULTS: Trainees screened 1,072 eligible women using our methodology. Within 1 month of training, the agreement rate between trainees and expert reviewers was 96.8%. Providers received a response from expert reviewers within 1 to 5 minutes 48.4% of the time, and more than 60% of the time, feedback was provided by regional expert reviewers in less than 10 minutes. CONCLUSION: Our method was found to be feasible and effective in increasing health care workers' skills and accuracy. This method holds promise for improved quality of VIA-based CCS programs among health care providers in low-income countries.

Postthrombotic morbidity correlates with residual thrombus following catheter-directed thrombolysis for iliofemoral deep vein thrombosis.

BACKGROUND: Iliofemoral deep vein thrombosis (DVT) is associated with severe postthrombotic morbidity when treated with anticoagulation alone. Catheter-directed thrombolysis (CDT), with or without the addition of mechanical techniques, is increasingly recommended for patients with iliofemoral DVT, although its effect on postthrombotic syndrome is not established. This study examined the correlation of residual thrombus with postthrombotic syndrome after catheter-based attempts at thrombus removal in patients with iliofemoral DVT. METHODS: Seventy-one consecutive patients with iliofemoral DVT were treated with CDT. Pretreatment and posttreatment phlebograms were evaluated for quantity of residual thrombus by physicians blinded to clinical patient outcomes. Postthrombotic syndrome was assessed using CEAP and Villalta scores by examiners blinded to phlebographic results. Patients were grouped by the amount of residual thrombus in treated vein segments (group 1, ≤50%; group 2, >50%). Clinical score and postthrombotic outcomes were plotted vs residual thrombus. RESULTS: Sixty-three of 71 patients completed CEAP and Villalta analyses. Groups 1 and 2 had median CEAP scores of 1 and 4 (P = .025) and mean Villalta scores of 2.21 and 7.13, respectively (P = .011). There was a direct and significant correlation of clinical class of CEAP with residual thrombus (R(2) = .74; P = .004) and a direct linear correlation of Villalta score with residual thrombus (R(2) = .61; P = .0014). CONCLUSIONS: In patients with iliofemoral DVT treated with catheter-based techniques of thrombus removal, postthrombotic morbidity is related to residual thrombus. When thrombus clearance was complete, the postthrombotic syndrome was avoided. Residual thrombus is associated with an increasing risk of postthrombotic syndrome.

What can medical education learn from the neurobiology of learning?

The last several decades have seen a large increase in knowledge of the underlying biological mechanisms that serve learning and memory. The insights gleaned from neurobiological and cognitive neuroscientific experimentation in humans and in animal models have identified many of the processes at the molecular, cellular, and systems levels that occur during learning and the formation, storage, and recall of memories. Moreover, with the advent of noninvasive technologies to monitor patterns of neural activity during various forms of human cognition, the efficacy of different strategies for effective teaching can be compared. Considerable insight has also been developed as to how to most effectively engage these processes to facilitate learning, retention, recall, and effective use and application of the learned information. However, this knowledge has not systematically found its way into the medical education process. Thus, there are considerable opportunities for the integration of current knowledge about the biology of learning with educational strategies and curricular design. By teaching medical students in ways that use this knowledge, there is an opportunity to make medical education easier and more effective. The authors present 10 key aspects of learning that they believe can be incorporated into effective teaching paradigms in multiple ways. They also present recommendations for applying the current knowledge of the neurobiology of learning throughout the medical education continuum.

Quantity of clot lysed after catheter-directed thrombolysis for iliofemoral deep venous thrombosis correlates with postthrombotic morbidity.

BACKGROUND: International treatment guidelines now recognize the importance of thrombus removal to reduce postthrombotic morbidity when treating patients with extensive acute deep venous thrombosis (DVT). Studies have shown that thrombus resolution with catheter-directed thrombolysis in patients with iliofemoral DVT reduces postthrombotic morbidity, although patients unsuccessfully treated with catheter-directed thrombolysis (CDT) do not enjoy the same long-term benefit. The purpose of this study is to objectively assess whether the amount of clot reduction at the time of acute therapy correlates with long-term postthrombotic morbidity. METHODS: Forty-two patients who underwent catheter-directed and/or pharmacomechanical lysis of iliofemoral DVT were quantitatively evaluated. Patients had their degree of clot lysis quantified and were divided into two main groups for comparison. Group I (n = 33) had >50% clot lysis (mean, 84%) and group II (n = 9) had < or =50% lysis (mean, 42%). At a mean follow-up interval of 14 months, the degree of chronic venous disease was assessed by evaluators blinded to the degree of clot lysis. Evaluation of postthrombotic morbidity was performed using the Villalta scale, and the clinical class of CEAP, and quality-of-life (QOL) was assessed using the Short Form Health Survey (SF-36). RESULTS: Mean CEAP scores were 0.85 and 3.13 (P = .005), and Villalta scores were 2.38 and 6.25 (P = .009) in group I and group II, respectively. Patient QOL in group I was higher than group II in all parameters. Physical functioning (P = .035), role physical (P = .012), general health (P = .014), vitality (P < .001), and social functioning (P = .012) were all significantly better in group I. Bodily pain (P = .117), role emotional (P = .624), and mental health (P = .096) strongly favored group I patients but did not reach statistical significance. CONCLUSION: Patients with extensive DVT treated with catheter-based interventions to eliminate thrombus suffer relatively little postthrombotic morbidity. The degree of clot lysis directly correlates with long-term outcome. Improved QOL, the Villalta scale, and clinical class of CEAP are linearly correlated with the amount of clot resolution.

How sensitive are multilevel regression findings to defined area of context?: a case study of mammography use in California.

The authors develop a hybrid model of health care use that blends features of the traditional Aday-Andersen behavioral model with the socioecological modeling perspective. They use the model to conceptualize the various levels of influence expected from socioecological variables in individuals' mammography use decisions, build contextual variables from fine-grained data into four different types of geographic areas, and then use two- and three-level modeling of personal and area-level contextual factors to explain observed behavior. The central focus is on whether differentiating the conceptualized levels of influence seems to materially affect regression findings. The test could conceivably be confounded by the modifiable areal unit problem, but little evidence for this is found. Findings for California women suggest that distinctions do matter in how the levels of influence are defined for local neighborhood contextual factors. Studies using only county-level contextual factors will miss some meaningful associations related to interpersonal/proximate-level factors.

Combined effect of packaging atmosphere and storage temperature on growth of Listeria monocytogenes on ready-to-eat shrimp.

Cooked, peeled, and deveined shrimp were inoculated with a 5 strain mixture of Listeria monocytogenes and packaged in air, vacuum, and a 100% carbon dioxide modified atmosphere. The packaged shrimp were then stored at 3, 7, and 12 degrees C for 15 days to monitor the growth of L. monocytogenes and psychrotrophic bacteria. Uninoculated shrimp were also subjected to sensory evaluation by a trained panel to measure odor and appearance over the storage period. Results demonstrated that shrimp packaged in CO(2) and stored at 3 degrees C did not permit growth of L. monocytogenes during the 15-day storage period, while all other packaging/temperature combinations allowed for multiplication of the bacterium. Carbon dioxide packaging also resulted in the slowest growth of psychrotrophic bacteria and resulted in shrimp having acceptable sensory odor and appearance scores at the end of storage. When strict temperature control is difficult, such as during processing, transportation, retail display, or home use, additional antimicrobial hurdles may be necessary to ensure safety.

Comparison of kinetic models to describe high pressure and gamma irradiation used to inactivate Vibrio vulnificus and Vibrio parahaemolyticus prepared in buffer solution and in whole oysters.

Comparisons of different models in inactivation kinetics were conducted on data obtained from high-pressure and gamma-irradiation processing. Vibrio vulnificus (MO-624) and Vibrio parahaemolyticus (O3:K6 TX-2103) suspended in phosphate-buffered saline (pH 7.4, 10(7) CFU/ml) were exposed to pressures from 207 to 379 MPa for 1 to 20 min. Inoculated whole oysters (106 CFU/g) were exposed to pressure from 276 to 379 MPa for 1 to 15 min. Pure cultures and inoculated oysters (10(6) CFU/g) also were irradiated (gamma irradiation) at doses of less than 3 kGy. Four mathematical models, the Bigelow model, Arrhenius equation, Fermi equation, and Weibull frequency distributions, were applied to microbial survival data, and performances of the different kinetic models were compared. Weibull frequency distributions can predict the high-pressure inactivation of Vibrio spp. with more accuracy in both pure cultures and inoculated oyster samples. The Fermi model provided a better description of gamma-irradiation inactivation kinetics compared with the traditional Bigelow model.

Linking field-based ecological data with remotely sensed data using a geographic information system in two malaria endemic urban areas of Kenya.

BACKGROUND: Remote sensing technology provides detailed spectral and thermal images of the earth's surface from which surrogate ecological indicators of complex processes can be measured. METHODS: Remote sensing data were overlaid onto georeferenced entomological and human ecological data randomly sampled during April and May 2001 in the cities of Kisumu (population asymptotically equal to 320,000) and Malindi (population asymptotically equal to 81,000), Kenya. Grid cells of 270 meters x 270 meters were used to generate spatial sampling units for each city for the collection of entomological and human ecological field-based data. Multispectral Thermal Imager (MTI) satellite data in the visible spectrum at five meter resolution were acquired for Kisumu and Malindi during February and March 2001, respectively. The MTI data were fit and aggregated to the 270 meter x 270 meter grid cells used in field-based sampling using a geographic information system. The normalized difference vegetation index (NDVI) was calculated and scaled from MTI data for selected grid cells. Regression analysis was used to assess associations between NDVI values and entomological and human ecological variables at the grid cell level. RESULTS: Multivariate linear regression showed that as household density increased, mean grid cell NDVI decreased (global F-test = 9.81, df 3,72, P-value = <0.01; adjusted R2 = 0.26). Given household density, the number of potential anopheline larval habitats per grid cell also increased with increasing values of mean grid cell NDVI (global F-test = 14.29, df 3,36, P-value = <0.01; adjusted R2 = 0.51). CONCLUSIONS: NDVI values obtained from MTI data were successfully overlaid onto georeferenced entomological and human ecological data spatially sampled at a scale of 270 meters x 270 meters. Results demonstrate that NDVI at such a scale was sufficient to describe variations in entomological and human ecological parameters across both cities.

Radiosensitivity of Listeria monocytogenes at Various Temperatures and Cell Concentrations.

Among food-borne pathogens, Listeria monocytogenes is more radiation resistant than gram-negative bacteria of the genera Salmonella and Vibrio . This study was designed to determine if initial cell concentration and/or temperature at the time of irradiation influences the radiosensitivity of L. monocytogenes . Concentrations of 103, 106, and 109 CFU (colony-forming units)/ml of L. monocytogenes Scott A were suspended in tryptic soy broth and exposed to 0 to 5 kGy of gamma radiation (1.25 MeV) at 20, 4, and -80°C. Survivors were enumerated and irradiation D-values were calculated using regression analysis and total-dose methods. A 103 CFU/ml population was destroyed with a <2 kGy dose. The irradiation D-value of 0.43 kGy when calculated by regression analysis for frozen (-80°C) cultures of 106 CFU/ml was significantly lower (P < 0.05) than those (0.58 and 0.62 kGy) at 20° and 4°C, respectively. However, the -80°C D-value was not significantly different (0.61 kGy) when calculated by the total dose required to eliminate all recovery. At 109 CFU/ml, a D-value (calculated by both methods) of 0.42 kGy was obtained at both 4° and -80°C, which was significantly lower (P < 0.05) than 0.50 kGy for 20°C suspensions. The temperature of irradiation only influenced the radiosensitivity of L. monocytogenes at 109 CFU/ml.