A GIS-based method for household recruitment in a prospective pesticide exposure study

<p>Abstract</p> <p>Background</p> <p>Recent advances in GIS technology and remote sensing have provided new opportunities to collect ecologic data on agricultural pesticide exposure. Many pesticide studies have used historical or records-based data on crops and their associated pesticide applications to estimate exposure by measuring residential proximity to agricultural fields. Very few of these studies collected environmental and biological samples from study participants. One of the reasons for this is the cost of identifying participants who reside near study fields and analyzing samples obtained from them. In this paper, we present a cost-effective, GIS-based method for crop field selection and household recruitment in a prospective pesticide exposure study in a remote location. For the most part, our multi-phased approach was carried out in a research facility, but involved two brief episodes of fieldwork for ground truthing purposes. This method was developed for a larger study designed to examine the validity of indirect pesticide exposure estimates by comparing measured exposures in household dust, water and urine with records-based estimates that use crop location, residential proximity and pesticide application data. The study focused on the pesticide atrazine, a broadleaf herbicide used in corn production and one of the most widely-used pesticides in the U.S.</p> <p>Results</p> <p>We successfully used a combination of remotely-sensed data, GIS-based methods and fieldwork to select study fields and recruit participants in Illinois, a state with high corn production and heavy atrazine use. Our several-step process consisted of the identification of potential study fields and residential areas using aerial photography; verification of crop patterns and land use via site visits; development of a GIS-based algorithm to define recruitment areas around crop fields; acquisition of geocoded household-level data within each recruitment area from a commercial vendor; and confirmation of final participant household locations via ground truthing. The use of these procedures resulted in a sufficient sample of participants from 14 recruitment areas in seven Illinois counties.</p> <p>Conclusion</p> <p>One of the challenges in pesticide research is the identification and recruitment of study participants, which is time consuming and costly, especially when the study site is in a remote location. We have demonstrated how GIS-based processes can be used to recruit participants, increase efficiency and enhance accuracy. The method that we used ultimately made it possible to collect biological samples from a specific demographic group within strictly defined exposure areas, with little advance knowledge of the location or population.</p

Association of Cardiac Baroreflex Sensitivity with Blood Pressure Transients: Influence of Sex and Menopausal Status

The magnitude of decrease in blood pressure (BP) during a vasoactive drug bolus may be associated with the calculated baroreflex sensitivity (BRS). The purpose of the present study was to evaluate whether sympathetic and/or cardiac BRS relates to the extent of change in BP and whether this was altered by sex hormones. Fifty-one young women (27 ± 1 years), 14 older women (58 ± 1 years), and 36 young men (27 ± 1 years) were studied. Heart rate, BP, and muscle sympathetic nerve activity (MSNA) were monitored. Sympathetic BRS was analyzed using the slope of the MSNA-diastolic blood pressure (DBP) relationship and cardiac BRS was analyzed using the R–R interval-systolic blood pressure (SBP) relationship. Young women and men had similar mean arterial pressures (MAP, 91 ± 1 vs. 90 ± 1 mmHg), cardiac BRS (19 ± 1 vs. 21 ± 2 ms/mmHg), and sympathetic BRS (−6 ± 1 vs. −7 ± 1 AU/beat/mmHg), respectively. Older women had higher MAP (104 ± 4 mmHg, p < 0.05) and lower cardiac BRS (7 ± 1 ms/mmHg, p < 0.05), but similar sympathetic BRS (−8 ± 1 AU/beat/mmHg). There was no association between BP transients with either cardiac or sympathetic BRS in young women. In the older women, the drop in SBP, DBP, and MAP were associated with cardiac BRS (r = 0.60, r = 0.59, and r = 0.70, respectively; p < 0.05), but not sympathetic BRS. The decrease in SBP was positively related to cardiac BRS in young men (r = 0.41; p < 0.05). However, there was no relationship between the decrease in BP and sympathetic BRS. This indicates that older women and young men with low cardiac BRS have larger transients in BP during nitroprusside. This suggests a more prominent role for cardiac (as opposed to sympathetic) BRS in responding to acute BP changes in young men and older women. The fact that these relationships do not exist in young women suggest that the female sex hormones influence baroreflex responses

Pharmacological assessment of the contribution of the arterial baroreflex to sympathetic discharge patterns in healthy humans

To study how changes in baroreceptor afferent activity affect patterns of sympathetic neural activation, we manipulated arterial blood pressure with intravenous nitroprusside (NTP) and phenylephrine (PE) and measured action potential (AP) patterns with wavelet-based methodology. We hypothesized that 1) baroreflex unloading (NTP) would increase firing of low-threshold axons and recruitment of latent axons and 2) baroreflex loading (PE) would decrease firing of low-threshold axons. Heart rate (HR, ECG), arterial blood pressure (BP, brachial catheter), and muscle sympathetic nerve activity (MSNA, microneurography of peroneal nerve) were measured at baseline and during steady-state systemic, intravenous NTP (0.5-1.2 µg·kg -1 ·min -1 , n = 13) or PE (0.2-1.0 µg·kg -1 ·min -1 , n = 9) infusion. BP decreased and HR and integrated MSNA increased with NTP (P \u3c 0.01). AP incidence (326 ± 66 to 579 ± 129 APs/100 heartbeats) and AP content per integrated burst (8 ± 1 to 11 ± 2 APs/burst) increased with NTP (P \u3c 0.05). The firing probability of low-threshold axons increased with NTP, and recruitment of high-threshold axons was observed (22 ± 3 to 24 ± 3 max cluster number, 9 ± 1 to 11 ± 1 clusters/burst; P \u3c 0.05). BP increased and HR and integrated MSNA decreased with PE (P \u3c 0.05). PE decreased AP incidence (406 ± 128 to 166 ± 42 APs/100 heartbeats) and resulted in fewer unique clusters (15 ± 2 to 9 ± 1 max cluster number, P \u3c 0.05); components of an integrated burst (APs or clusters per burst) were not altered (P \u3e 0.05). These data support a hierarchical pattern of sympathetic neural activation during manipulation of baroreceptor afferent activity, with rate coding of active neurons playing the predominant role and recruitment/derecruitment of higher-threshold units occurring with steady-state hypotensive stress. NEW & NOTEWORTHY To study how changes in baroreceptor afferent activity affect patterns of sympathetic neural activation, we manipulated arterial blood pressure with intravenous nitroprusside and phenylephrine and measured sympathetic outflow with wavelet-based methodology. Baroreflex unloading increased sympathetic activity by increasing firing probability of low-threshold axons (rate coding) and recruiting new populations of high-threshold axons. Baroreflex loading decreased sympathetic activity by decreasing the firing probability of larger axons (derecruitment); however, the components of an integrated burst were unaffected

Developing a National Implementation Strategy to accelerate Uptake of Evidence-Based Family Caregiver Support in Us Cancer Centers

OBJECTIVE: Characterize key factors and training needs of U.S. cancer centers in implementing family caregiver support services. METHODS: Sequential explanatory mixed methods design consisting of: (1) a national survey of clinicians and administrators from Commission-on-Cancer-accredited cancer centers (N = 238) on factors and training needed for establishing new caregiver programs and (2) qualitative interviews with a subsample of survey respondents (N = 30) to elicit feedback on survey findings and the outline of an implementation strategy to facilitate implementation of evidence-based family caregiver support (the Caregiver Support Accelerator). Survey data was tabulated using descriptive statistics and transcribed interviews were analyzed using thematic analysis. RESULTS: top factors for developing new caregiver programs were that the program be: consistent with the cancer center\u27s mission and strategic plan (87%), supported by clinic leadership (86.5%) and providers and staff (85.7%), and low cost or cost effective (84.9%). top training needs were how to: train staff to implement programs (72.3%), obtain program materials (63.0%), and evaluate program outcomes (62.6%). Only 3.8% reported that no training was needed. Qualitative interviews yielded four main themes: (1) gaining leadership, clinician, and staff buy-in and support is essential; (2) cost and clinician burden are major factors to program implementation; (3) training should help with adapting and marketing programs to local context and culture; and (4) the Accelerator strategy is comprehensive and would benefit from key organizational partnerships and policy standards. CONCLUSION: Findings will be used to inform and refine the Accelerator implementation strategy to facilitate the adoption and growth of evidence-based cancer caregiver support in U.S. cancer centers

Availability of Family Caregiver Programs in Us Cancer Centers

IMPORTANCE: Family caregivers provide the majority of health care to the 18 million patients with cancer in the US. Yet despite providing complex medical and nursing care, a large proportion of caregivers report no formal support or training. In recognition of this gap, many interventions to support cancer caregivers have been developed and tested over the past 2 decades. However, there are few system-level data on whether US cancer centers have adopted and implemented these interventions. OBJECTIVE: to describe and characterize the availability of family caregiver support programs in US cancer centers. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional national survey study was conducted between September 1, 2021, and April 30, 2023. Participants comprised clinical and administrative staff of Commission on Cancer-accredited US cancer centers. Data analysis was performed in May and June 2023. MAIN OUTCOMES AND MEASURES: Survey questions about the availability of 11 types of family caregiver programs (eg, peer mentoring, education classes, and psychosocial programs) were developed after literature review, assessment of similar program evaluation surveys, and discussions among a 13-member national expert advisory committee. Family caregiver programs were defined as structured, planned, and coordinated groups of activities and procedures aimed at specifically supporting family caregivers as part of usual care. Survey responses were tabulated using standard descriptive statistics, including means, proportions, and frequencies. RESULTS: Of the surveys sent to potential respondents at 971 adult cancer centers, 238 were completed (response rate, 24.5%). After nonresponse weight adjustment, most cancer centers (75.4%) had at least 1 family caregiver program; 24.6% had none. The most common program type was information and referral services (53.6%). Cancer centers with no programs were more likely to have smaller annual outpatient volumes (χ2 = 11.10; P = .011). Few centers had caregiver programs on training in medical and/or nursing tasks (21.7%), caregiver self-care (20.2%), caregiver-specific distress screening (19.3%), peer mentoring (18.9%), and children caregiving for parents (8.3%). Very few programs were developed from published evidence in a journal (8.1%). The top reason why cancer centers selected their programs was community members requesting the program (26.3%); only 12.3% of centers selected their programs based on scientific evidence. Most programs were funded by the cancer center or hospital (58.6%) or by philanthropy (42.4%). CONCLUSIONS AND RELEVANCE: In this survey study, most cancer centers had family caregiver programs; however, a quarter had none. Furthermore, the scope of programming was limited and rarely evidence based, with few centers offering caregiving education and training. These findings suggest that implementation strategies are critically needed to foster uptake of evidence-based caregiver interventions

Aging in females is associated with changes in respiratory modulation of sympathetic nerve activity and blood pressure

Sympathetic nerve activity (SNA) is tightly coupled with the respiratory cycle. In healthy human males, respiratory modulation of SNA does not change with age. However, it is unclear how this modulation is affected by age in females. We investigated whether respiratory sympathetic modulation is altered in healthy postmenopausal (PMF) versus premenopausal female (YF), and younger male (YM) adults, and determined its relationship to resting blood pressure. Muscle SNA (MSNA; microneurography), respiration (transducer belt), ECG, and continuous blood pressure were measured in 12 YF, 13 PMF, and 12 YM healthy volunteers. Respiratory modulation of MSNA was quantified during two phases of the respiratory cycle: mid-late expiration and inspiration/postinspiration. All groups showed respiratory modulation of MSNA (P < 0.0005). There was an interaction between the respiratory phase and group for MSNA [bursts/100 heartbeats (HB) (P ¼ 0.004) and bursts/min (P ¼ 0.029)], with smaller reductions in MSNA during inspiration observed in PMF versus the other groups. Respiratory modulation of blood pressure was also reduced in PMF versus YF (6 [2] vs. 12 [9] mmHg, P ¼ 0.008) and YM (13 [13] mmHg, P ¼ 0.001, median [interquartile range]). The magnitude of respiratory sympathetic modulation was related to resting blood pressure in PMF only, such that individuals with less modulation had greater resting blood pressure. The data indicate that aging in postmenopausal females is associated with less inspiratory inhibition of MSNA. This correlated with a higher resting blood pressure in PMF only. Thus, the reduced modulation of MSNA could contribute to the age-related rise in blood pressure that occurs in females. NEW & NOTEWORTHY The current study demonstrates that respiratory modulation of sympathetic nerve activity (SNA) is reduced in healthy postmenopausal (PMF) versus premenopausal females (YF). Furthermore, respiratory sympathetic modulation was negatively related to resting blood pressure in postmenopausal females, such that blood pressure was greater in individual with less modulation. Reduced respiratory sympathetic modulation may have implications for the autonomic control of blood pressure in aging postmenopausal females, by contributing to age-related sympathetic activation and reducing acute, respiratory-linked blood pressure variation

16th Annual Environmental Law Institute

Materials from the 16th Annual Environmental Law Institute held by UK/CLE in May 2000

Caenorhabditis elegans Genomic Response to Soil Bacteria Predicts Environment-Specific Genetic Effects on Life History Traits

With the post-genomic era came a dramatic increase in high-throughput technologies, of which transcriptional profiling by microarrays was one of the most popular. One application of this technology is to identify genes that are differentially expressed in response to different environmental conditions. These experiments are constructed under the assumption that the differentially expressed genes are functionally important in the environment where they are induced. However, whether differential expression is predictive of functional importance has yet to be tested. Here we have addressed this expectation by employing Caenorhabditis elegans as a model for the interaction of native soil nematode taxa and soil bacteria. Using transcriptional profiling, we identified candidate genes regulated in response to different bacteria isolated in association with grassland nematodes or from grassland soils. Many of the regulated candidate genes are predicted to affect metabolism and innate immunity suggesting similar genes could influence nematode community dynamics in natural systems. Using mutations that inactivate 21 of the identified genes, we showed that most contribute to lifespan and/or fitness in a given bacterial environment. Although these bacteria may not be natural food sources for C. elegans, we show that changes in food source, as can occur in environmental disturbance, can have a large effect on gene expression, with important consequences for fitness. Moreover, we used regression analysis to demonstrate that for many genes the degree of differential gene expression between two bacterial environments predicted the magnitude of the effect of the loss of gene function on life history traits in those environments

Necator americanus and Helminth Co-Infections: Further Down-Modulation of Hookworm-Specific Type 1 Immune Responses

Parasitic infections in humans are common in tropical regions and under bad housing and sanitation conditions multiple parasitic infections are the rule rather than the exception. For helminth infections, which are thought to affect almost a quarter of the world's population, most common combinations include soil-transmitted helminths, such as hookworm, roundworm, and whipworm, as well as extra-intestinal infections by schistosomes. In order to develop and test a hookworm vaccine in endemic areas, the understanding of the impact of multiple helminth infections (co-infection) on the immune response against hookworm in infected individuals is crucial. The authors report in their article, that several parameters of the cellular (T cell markers, cytokines, chemokines) and humoral immune response (e.g. IgG4 and IgE antibodies) against hookworm are significantly affected or modulated in individuals co-infected with hookworm, roundworm and/or schistosomes. These results imply that the immune response against components of a hookworm vaccine might be altered by previous contact with other helminth species in endemic areas