The wildland firefighter exposure and health effect (WFFEHE) study: cohort characteristics and health behavior changes in context

OBJECTIVES

Work is an under-recognized social determinant of health. There is limited research describing US wildland firefighter (WFF) workforce demographics or how to work associates with WFF health behaviors. In this study researchers characterized a WFF cohort and tested hypotheses that WFFs used tobacco, alcohol, and sugar-sweetened beverages (SSBs) differently over the course of the fire season and that different fire crews may exhibit different behavior patterns.

METHODS

Researchers collected data in the field with 6 WFF crews during 2 consecutive fire seasons (2018 and 2019). WFF crews completed questionnaires before and after each season. WFFs with an initial preseason questionnaire and at least 1 follow-up questionnaire were included (n = 138). Descriptive statistics summarized WFFs' baseline demographic, employment, and health characteristics. Linear mixed models were used to test for changes in WFFs' substance use over time and assess crew-level differences. A meta-analysis of WFF longitudinal studies' population characteristics was attempted to contextualize baseline findings.

RESULTS

WFFs were predominately male, less than 35 yr of age, non-Hispanic White, and had healthy weight. Smokeless tobacco use and binge drinking were prevalent in this cohort (52% and 78%, respectively, among respondents). Longitudinal analyses revealed that during the fire season WFFs' use of tobacco and SSBs increased and the number of days they consumed alcohol decreased. Crew-level associations varied by substance. The meta-analysis was not completed due to cross-study heterogeneity and inconsistent reporting.

DISCUSSION

WFF agencies can promote evidence-based substance use prevention and management programs and modify working conditions that may influence WFF stress or substance use.

Suicide Rates by Industry and Occupation - National Vital Statistics System, United States, 2021

The suicide rate among the U.S. working-age population has increased approximately 33% during the last 2 decades. To guide suicide prevention strategies, CDC analyzed suicide deaths by industry and occupation in 49 states, using data from the 2021 National Vital Statistics System. Industry (the business activity of a person's employer or, if self-employed, their own business) and occupation (a person's job or the type of work they do) are distinct ways to categorize employment. The overall suicide rates by sex in the civilian noninstitutionalized working population were 32.0 per 100,000 among males and 8.0 per 100,000 among females. Major industry groups with the highest suicide rates included Mining (males = 72.0); Construction (males = 56.0; females = 10.4); Other Services (e.g., automotive repair; males = 50.6; females = 10.4); Arts, Entertainment, and Recreation (males = 47.9; females = 15.0); and Agriculture, Forestry, Fishing, and Hunting (males = 47.9). Major occupation groups with the highest suicide rates included Construction and Extraction (males = 65.6; females = 25.3); Farming, Fishing, and Forestry (e.g., agricultural workers; males = 49.9); Personal Care and Service (males = 47.1; females = 15.9); Installation, Maintenance, and Repair (males = 46.0; females = 26.6); and Arts, Design, Entertainment, Sports, and Media (males = 44.5; females = 14.1). By integrating recommended programs, practices, and training into existing policies, workplaces can be important settings for suicide prevention. CDC provides evidence-based suicide prevention strategies in its Suicide Prevention Resource for Action and Critical Steps Your Workplace Can Take Today to Prevent Suicide, NIOSH Science Blog.

Fatalities Involving Substance Use Among US Oil and Gas Extraction Workers Identified Through an Industry Specific Surveillance System (2014-2019)

OBJECTIVE

Characteristics of oil and gas extraction (OGE) work, including long hours, shiftwork, fatigue, physically demanding work, and job insecurity are risk factors for substance use among workers. Limited information exists examining worker fatalities involving substance use among OGE workers.

METHODS

The National Institute for Occupational Safety and Health's Fatalities in Oil and Gas Extraction database was screened for fatalities involving substance use from 2014 through 2019.

RESULTS

Twenty-six worker deaths were identified as involving substance use. Methamphetamine or amphetamine was the most common substances (61.5%) identified. Other contributing factors were lack of seatbelt use (85.7%), working in high temperatures (19.2%), and workers' first day with the company (11.5%).

CONCLUSIONS

Employer recommendations to mitigate substance use-related risks in OGE workers include training, medical screening, drug testing, and workplace supported recovery programs.

Working Alone and/or in Remote Locations: Opportunities to Prevent the Risk of Fatality From Cardiovascular Events in Oil and Gas Extraction Workers

OBJECTIVE

The aim of the study is to explore personal and work factors related to fatal cardiac events among oil and gas extraction (OGE) workers.

METHODS

The National Institute for Occupational Safety and Health Fatalities in Oil and Gas Extraction database was reviewed to identify fatal cardiac events among OGE workers from 2014 through 2019. A case series design was used to review case files, provide descriptive statistics, and summarize the findings.

RESULTS

There were 75 fatalities identified, including 55 (73%) with sufficient information for review. Of the 55 workers, 18 (33%) worked alone. Thirty-six fatal cardiac events (66%) were unwitnessed by a coworker. Toxicology findings suggested some possible exposures to hydrogen sulfide or hydrocarbon gases or vapors. Missing data were common.

CONCLUSIONS

This study identified the need for cardiovascular disease prevention and treatment, emergency preparedness, lone worker programs, medical screening, and enhanced exposure control in the OGE industry.

Association of falls and fear of falling with objectively-measured driving habits among older drivers: LongROAD study

OBJECTIVE

Falls in older adults are associated with increased motor vehicle crash risk, possibly mediated by driving behavior. We examined the relationship of falls and fear of falling (FOF) with subsequent objectively measured driving habits.

METHODS

This multi-site, prospective cohort study enrolled 2990 active drivers aged 65-79 (53% female). At enrollment, we assessed falls in the past year and FOF (Short Falls Efficacy Scale-International). Driving outcomes included exposure, avoidance of difficult conditions, and unsafe driving during one-year follow-up, using in-vehicle Global Positioning System devices.

RESULTS

Past-year falls were associated with more hard braking events (HBE). High FOF was associated with driving fewer days, miles, and trips, driving nearer home and more HBE. Differences were attenuated and not significant after accounting for health, function, medications and sociodemographics.

DISCUSSION

Differences in objectively measured driving habits according to past-year fall history and FOF were largely accounted for by differences in health and medications. Rather than directly affecting driving, falls and FOF may serve as markers for crash risk and reduced community mobility due to age-related changes and poor health.

Self-reported exposure to hazards and mitigation strategies among oil and gas extraction workers in three U.S. states

Numerous health and safety hazards exist at U.S. onshore oil and gas extraction worksites. Higher fatal injury rates have been reported among drilling and servicing companies, which are more likely to employ workers in construction and extraction occupations, compared to operators that employ more workers in management and office and administrative support roles. However, there is little information describing the extent to which workers encounter these hazards, are provided hazard mitigation strategies by their employers, or use personal protective equipment (PPE). A cross-sectional survey of 472 U.S. oil and gas extraction workers was conducted to identify and characterize factors related to on-the-job fatalities, injuries, and illnesses and determine workers' health and safety concerns. Workers were employed by servicing companies (271/472, 57.4%), drilling contractors (106/472, 22.5%), and operators (95/472, 20.1%). The likelihood of contact with hazardous substances varied by substance and company type. Drilling and servicing employees had significantly higher odds of self-reported contact with pipe dope (ORdrilling = 10.07, 95% CI: 1.74-63.64; ORservicing = 5.95, 95% CI: 2.18-18.34), diesel exhaust (ORdrilling = 2.28, 95% CI: 1.15-5.05; ORservicing = 4.93, 95% CI: 2.73-10.32), and drilling mud (ORdrilling = 24.36, 95% CI: 4.45-144.69; ORservicing = 3.48, 95% CI: 1.24-12.20), compared to operators. Safety policies, programs, and trainings were commonly reported by workers, although substance-specific training (e.g., respirable crystalline silica hazards) was less common. Differences in self-reported employer PPE requirements and worker use of PPE when needed or required for safety highlight a need for novel strategies to improve the use of PPE. Overall, this study highlights differences in work conditions by company type and uncovers gaps in employer administrative controls and PPE use.

The Childhood Obesity Data Initiative: A Case Study in Implementing Clinical-Community Infrastructure Enhancements to Support Health Services Research and Public Health

CONTEXT

We describe a participatory framework that enhanced and implemented innovative changes to an existing distributed health data network (DHDN) infrastructure to support linkage across sectors and systems. Our processes and lessons learned provide a potential framework for other multidisciplinary infrastructure development projects that engage in a participatory decision-making process.

PROGRAM

The Childhood Obesity Data Initiative (CODI) provides a potential framework for local and national stakeholders with public health, clinical, health services research, community intervention, and information technology expertise to collaboratively develop a DHDN infrastructure that enhances data capacity for patient-centered outcomes research and public health surveillance. CODI utilizes a participatory approach to guide decision making among clinical and community partners.

IMPLEMENTATION

CODI's multidisciplinary group of public health and clinical scientists and information technology experts collectively defined key components of CODI's infrastructure and selected and enhanced existing tools and data models. We conducted a pilot implementation with 3 health care systems and 2 community partners in the greater Denver Metro Area during 2018-2020.

EVALUATION

We developed an evaluation plan based primarily on the Good Evaluation Practice in Health Informatics guideline. An independent third party implemented the evaluation plan for the CODI development phase by conducting interviews to identify lessons learned from the participatory decision-making processes.

DISCUSSION

We demonstrate the feasibility of rapid innovation based upon an iterative and collaborative process and existing infrastructure. Collaborative engagement of stakeholders early and iteratively was critical to ensure a common understanding of the research and project objectives, current state of technological capacity, intended use, and the desired future state of CODI architecture. Integration of community partners' data with clinical data may require the use of a trusted third party's infrastructure. Lessons learned from our process may help others develop or improve similar DHDNs.

A Governance Framework to Integrate Longitudinal Clinical and Community Data in a Distributed Data Network: The Childhood Obesity Data Initiative

CONTEXT

Integrating longitudinal data from community-based organizations (eg, physical activity programs) with electronic health record information can improve capacity for childhood obesity research.

OBJECTIVE

A governance framework that protects individual privacy, accommodates organizational data stewardship requirements, and complies with laws and regulations was developed and implemented to support the harmonization of data from disparate clinical and community information systems.

PARTICIPANTS AND SETTING

Through the Childhood Obesity Data Initiative (CODI), 5 Colorado-based organizations collaborated to expand an existing distributed health data network (DHDN) to include community-generated data and assemble longitudinal patient records for research.

DESIGN

A governance work group expanded an existing DHDN governance infrastructure with CODI-specific data use and exchange policies and procedures that were codified in a governance plan and a delegated-authority, multiparty, reciprocal agreement.

RESULTS

A CODI governance work group met from January 2019 to March 2020 to conceive an approach, develop documentation, and coordinate activities. Governance requirements were synthesized from the CODI use case, and a customized governance approach was constructed to address governance gaps in record linkage, a procedure to request data, and harmonizing community and clinical data. A Master Sharing and Use Agreement (MSUA) and Memorandum of Understanding were drafted and executed to support creation of linked longitudinal records of clinical- and community-derived childhood obesity data. Furthermore, a multiparty infrastructure protocol was approved by the local institutional review board (IRB) to expedite future CODI research by simplifying IRB research applications.

CONCLUSION

CODI implemented a clinical-community governance strategy that built trust between organizations and allowed efficient data exchange within a DHDN. A thorough discovery process allowed CODI stakeholders to assess governance capacity and reveal regulatory and organizational obstacles so that the governance infrastructure could effectively leverage existing knowledge and address challenges. The MSUA and complementary governance documents can inform similar efforts.

A process to deduplicate individuals for regional chronic disease prevalence estimates using a distributed data network of electronic health records

Introduction

Learning health systems can help estimate chronic disease prevalence through distributed data networks (DDNs). Concerns remain about bias introduced to DDN prevalence estimates when individuals seeking care across systems are counted multiple times. This paper describes a process to deduplicate individuals for DDN prevalence estimates.

Methods

We operationalized a two‐step deduplication process, leveraging health information exchange (HIE)‐assigned network identifiers, within the Colorado Health Observation Regional Data Service (CHORDS) DDN. We generated prevalence estimates for type 1 and type 2 diabetes among pediatric patients (0‐17 years) with at least one 2017 encounter in one of two geographically‐proximate DDN partners. We assessed the extent of cross‐system duplication and its effect on prevalence estimates.

Results

We identified 218 437 unique pediatric patients seen across systems during 2017, including 7628 (3.5%) seen in both. We found no measurable difference in prevalence after deduplication. The number of cases we identified differed slightly by data reconciliation strategy. Concordance of linked patients' demographic attributes varied by attribute.

Conclusions

We implemented an HIE‐dependent, extensible process that deduplicates individuals for less biased prevalence estimates in a DDN. Our null pilot findings have limited generalizability. Overlap was small and likely insufficient to influence prevalence estimates. Other factors, including the number and size of partners, the matching algorithm, and the electronic phenotype may influence the degree of deduplication bias. Additional use cases may help improve understanding of duplication bias and reveal other principles and insights. This study informed how DDNs could support learning health systems' response to public health challenges and improve regional health.

Associations Between Socioeconomic Context and Congenital Heart Disease Related Outcomes in Adolescents and Adults

Little is known about the relation between socioeconomic factors and health outcomes in adults and adolescents with congenital heart defects (CHD). Population-level data from the Colorado CHD surveillance system from 2011 to 2013 was used to examine the association between area deprivation and outcomes including hospitalizations, emergency department visits, cardiac procedures, all-cause and cardiac-related mortality, and major adverse cardiac events. Socioeconomic context was measured by the Area Deprivation Index at census tract level. Missing race/ethnicity was imputed using the Bayesian Improved Surname Geocoding algorithm. Generalized linear models were utilized to examine health disparities across deprivation quintiles after adjusting for insurance type, race/ethnicity, age, gender, urbanicity, and CHD severity in 5,748 patients. Cases residing in the most deprived quintile had 51% higher odds of inpatient admission, 74% higher odds of emergency department visit, 41% higher odds of cardiac surgeries, and 45% higher odds of major adverse cardiac events compared with cases in the least deprived quintile. Further, rates of hospitalizations, emergency department admissions, and cardiac surgeries were elevated in the most deprived compared with the least deprived quintile. Mortality was not significantly different across quintiles. In conclusion, findings suggest significant health equity issues for adolescent and adults with CHD based on area-based deprivation.

Evaluating Population Coverage in a Regional Distributed Data Network: Implications for Electronic Health Record-Based Public Health Surveillance

OBJECTIVE

Electronic health records (EHRs) hold promise as a public health surveillance tool, but questions remain about how EHR patients compare with populations in health and demographic surveys. We compared population characteristics from a regional distributed data network (DDN), which securely and confidentially aggregates EHR data from multiple health care organizations in the same geographic region, with population characteristics from health and demographic surveys.

METHODS

Ten health care organizations participating in a Colorado DDN contributed data for coverage estimation. We aggregated demographic and geographic data from 2017 for patients aged ≥18 residing in 7 counties. We used a cross-sectional design to compare DDN population size, by county, with the following survey-estimated populations: the county population, estimated by the American Community Survey (ACS); residents seeking any health care, estimated by the Colorado Health Access Survey; and residents seeking routine (eg, primary) health care, estimated by the Behavioral Risk Factor Surveillance System. We also compared data on the DDN and survey populations by sex, age group, race/ethnicity, and poverty level to assess surveillance system representativeness.

RESULTS

The DDN population included 609 840 people in 7 counties, corresponding to 25% coverage of the general adult population. Population coverage ranged from 15% to 35% across counties. Demographic distributions generated by DDN and surveys were similar for many groups. Overall, the DDN and surveys assessing care-seeking populations had a higher proportion of women and older adults than the ACS population. The DDN included higher proportions of Hispanic people and people living in high-poverty neighborhoods compared with the surveys.

CONCLUSION

The DDN population is not a random sample of the regional adult population; it is influenced by health care use patterns and organizations participating in the DDN. Strengths and limitations of DDNs complement those of survey-based approaches. The regional DDN is a promising public health surveillance tool.

Same-Day HIV Pre-Exposure Prophylaxis (PrEP) Initiation During Drop-in Sexually Transmitted Diseases Clinic Appointments Is a Highly Acceptable, Feasible, and Safe Model that Engages Individuals at Risk for HIV into PrEP Care

Objective

Strategies to increase pre-exposure prophylaxis (PrEP) uptake are needed. We hypothesized that same-day PrEP initiation in a sexually transmitted diseases (STD) clinic would be acceptable, feasible, and safe, and that individuals would engage in ongoing PrEP care.

Method

Individuals aged ≥ 18 years were evaluated for PrEP. Exclusion criteria were HIV, history of renal dysfunction or chronic hepatitis B infection, pregnancy, indications for HIV post-exposure prophylaxis, or positive screen for acute HIV symptoms. One hundred individuals received a free 30-day PrEP starter pack and met with a patient navigator to establish ongoing care. Bivariate analysis and multivariable logistic regression were used to compare individuals who did and did not attend at least 1 PrEP follow-up appointment within 180 days of enrollment. Client satisfaction surveys were given 3 months after enrollment.

Results

The majority (78%) of participants completed at least 1 PrEP follow-up appointment, and 57% attended at least 2 follow-up appointments. After adjusting for race and ethnicity, age, health insurance status, and annual income, only income was associated with follow-up appointment attendance. Each additional $10,000 increase in income was associated with a 1.7-fold increase in the odds of attending a PrEP follow-up appointment (95% confidence interval, 1.07–2.66, P = .02). The majority (54%) of individuals completed the satisfaction survey and all respondents liked the option of same-day PrEP initiation.

Conclusions

Our study suggests STD clinic-based, same-day PrEP initiation is acceptable, feasible, safe, and links a high proportion of individuals into ongoing PrEP care. Additional resources may be needed to support low-income individuals’ retention in care.

Early labor force exit subsequent to permanently impairing occupational injury or illness among workers 50-64 years of age

BACKGROUND

Severity of workplace injury tends to increase with age. Whether older workers who experience a workplace injury or illness exit the labor force sooner than comparable peers is not established.

METHODS

A case-cohort study design and complementary log-log model were used to identify factors associated with average time to early substantial labor force exit among workers' compensation claimants 50-64 years of age with permanent impairment from an occupational injury or illness. Analysis was based on Ontario's workers' compensation claimant data from 1998 to 2006 linked with Canadian tax files.

RESULTS

Workers with permanent impairment left the labor force earlier, on average, than peers without claims. Early retirement was associated with older age in the injury/illness year, greater impairment, lower pre-claim income, physically demanding jobs, and soft-tissue injuries.

CONCLUSIONS

Policies aiming to extend older adults' working lives should account for the potentially disparate impacts on older workers of occupational injury and illness.

Same-level fall injuries in US workplaces by age group, gender, and industry

BACKGROUND

As the workforce ages, occupational injuries from falls on the same level will increase. Some industries may be more affected than others.

METHODS

We conducted a cross-sectional study using data from the Bureau of Labor Statistics to estimate same-level fall injury incidence rates by age group, gender, and industry for four sectors: 1) healthcare and social assistance; 2) manufacturing; 3) retail; and 4) transportation and warehousing. We calculated rate ratios and rate differences by age group and gender.

RESULTS

Same-level fall injury incidence rates increase with age in all four sectors. However, patterns of rate ratios and rate differences vary by age group, gender, and industry. Younger workers, men, and manufacturing workers generally have lower rates.

CONCLUSIONS

Variation in incidence rates suggests there are unrealized opportunities to prevent same-level fall injuries. Interventions should be evaluated for their effectiveness at reducing injuries, avoiding gender- or age-discrimination and improving work ability.

Associations Between Falls and Driving Outcomes in Older Adults: Systematic Review and Meta-Analysis

OBJECTIVES

To examine associations between falls and subsequent motor vehicle crashes (MVCs), crash-related injuries, driving performance, and driving behavior.

DESIGN

Systematic review and metaanalysis.

PARTICIPANTS

Observational studies including drivers aged 55 and older or with a mean age of 65 and older.

MEASUREMENTS

Two authors independently extracted study and participant characteristics, exposures, and outcomes and assessed risk of bias. Pooled risk estimates for MVCs and MVC-related injuries were calculated using random-effects models. Other results were synthesized narratively.

RESULTS

From 3,286 potentially eligible records, 15 studies (N = 27-17,349 subjects) met inclusion criteria. Risk of bias was low to moderate, except for cross-sectional studies (n = 3), which all had a high potential for bias. A fall history was associated with a significantly greater risk of subsequent MVC (summary risk estimate = 1.40, 95% confidence interval (CI) = 1.20-1.63; I²  = 28%, N = 5 studies). One study found a significantly greater risk of MVC-related hospitalizations and deaths after a fall (hazard ratio = 3.12, 95% CI = 1.71-5.69). Evidence was inconclusive regarding an association between falls and driving cessation and showed no association between falls and driving performance or behavior.

CONCLUSION

Falls in older adults appear to be a risk marker for subsequent MVCs and MVC-related injury. Given the nature of the evidence, which is limited to observational studies, the identified associations may also result at least partly from confounding or bias. Further research is needed to clarify the mechanisms linking falls to crash risk and to develop effective interventions to ensure driving safety in older adults with a history of falls.

The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

Occupational physical activity assessment for chronic disease prevention and management: A review of methods for both occupational health practitioners and researchers

Occupational physical activity (OPA) is an occupational exposure that impacts worker health. OPA is amenable to measurement and modification through the hierarchy of controls. Occupational exposure scientists have roles in addressing inadequate physical activity, as well as excessive or harmful physical activity. Occupational health researchers can contribute to the development of novel OPA exposure assessment techniques and to epidemiologic studies examining the health impacts of physical activity at work. Occupational health practitioners stand to benefit from understanding the strengths and limitations of physical activity measurement approaches, such as accelerometers in smartphones, which are already ubiquitous in many workplaces and in some worksite health programs. This comprehensive review of the literature provides an overview of physical activity monitoring for occupational exposure scientists. This article summarizes data on the public health implications of physical activity at work, highlighting complex relationships with common chronic diseases. This article includes descriptions of several techniques that have been used to measure physical activity at work and elsewhere, focusing in detail on pedometers, accelerometers, and Global Positioning System technology. Additional subjective and objective measurement strategies are described as well.

Characterization of the feeding inhibition and neural activation produced by dorsomedial hypothalamic cholecystokinin administration

Within the dorsomedial hypothalamus (DMH), cholecystokinin (CCK) has been proposed to modulate neuropeptide Y (NPY) signaling to affect food intake. However, the neural circuitry underlying the actions of this CCK-NPY signaling system in the controls of food intake has yet to be determined. We sought to characterize the feeding inhibition and brain neural activation produced by CCK administration into the DMH of rats. We determined the time course of feeding inhibitory effects of exogenous DMH CCK, assessed NPY gene expression in the DMH in response to DMH CCK administration, and characterized c-Fos activation in the entire brain induced by CCK injection into the DMH using c-Fos like immunohistochemistry. We found that parenchymal injection of CCK into the DMH decreased food intake during the entire 22 h observation period, with a primary effect in the first 4 h, and down-regulated NPY gene expression in the DMH. c-Fos immunohistochemistry revealed that DMH CCK increased the number of c-Fos positive cells in the paraventricular nucleus (PVN), arcuate nucleus, suprachiasmatic nucleus and retrochiasmatic area as well as in the contralateral DMH. This pattern of activity is different from that produced by peripherally administered CCK which is short acting and primarily activates neurons in the nucleus of the solitary tract and area postrema, as well as the PVN and DMH. Together, these data suggest that DMH CCK plays an important role in the control of food intake, and does so by activating different pathways from those activated by peripheral CCK.

Postnatal behavioral and physiological responses of piglets from gilts housed individually or in groups during gestation

Gestational housing of sows remains a controversial issue that may affect the well-being of both sows and piglets. Therefore, 2 types of gestational housing were used to evaluate the stress imposed on pregnant gilts by each system and the effects on the offspring by comparing production, physiology, and behavioral measures of the piglets. Forty-eight Landrace x Yorkshire gilts were randomly assigned to groups (G) of 4 per pen (n = 8 pens; 3.9 m x 2.4 m) or to individual stalls (S; n = 16 stalls; 2.21 m x 0.61 m). Gilts were moved into individual farrowing crates 5 d before the expected farrowing date. Piglets were weighed at birth, d 14, and d 35. Two barrows from each litter were weaned at d 14 (early weaning) and housed together in pens. Maintenance behaviors (head in feeder, drinking, lying, eating mash) were videotaped and observed for the first 3 d after weaning using a 10-min interval scan sampling. Belly nosing and play/fight interactions were recorded from video observations for 3 d postweaning. An isolation test (30-min duration) was performed on one piglet from each pen of barrows on d 35. Time spent lying, the number of jumps against test box walls, and grunts and squeals were recorded in real time. Salivary cortisol was collected at 30-min intervals from baseline, and 0, 30, 60, and 90 min posttest. Jugular blood was collected from 2 barrows from each litter on d 1, 7, 14, 17, 21, and 28. Plasma TNF-alpha was analyzed by ELISA, and haptoglobin, alpha1-acid glycoprotein, and immunoglobulin G were analyzed by radial immunodiffusion. More piglets from the S treatment needed to be fed a liquid feed at weaning and drank more frequently on d 2 postweaning (P < 0.05). Additionally, by d 35 piglets from S gilts had a lighter BW (10.3 kg) than G piglets (12.8 kg; P < 0.01). Piglets from S gilts also grunted more during the 30-min isolation test (number of grunts = 356) than G piglets (number of grunts = 138; P < 0.01). Salivary cortisol and immune measures were not different. These data show some behavioral and production differences between piglets from individually stalled gilts and group-housed gilts. Therefore, there may be production advantages to housing first parity gilts in groups.

Neural Probes for Concurrent Detection of Neurochemical and Electrophysiological Signals in vivo

Electrochemical sensing with microelectrode arrays provides a means for monitoring neurotransmitter dynamics across multiple locations within a micro-scale region of brain tissue. Here we present a multi-modal neural probe design for concurrent recording of neurochemical and electrophysiological signals in vivo. Prior to implantation, platinum sites on each array underwent platinum-black electroplating and Nafion electropolymerization, which increased sensitivity to dopamine by 74% and decreased sensitivity to common interferents by at least 89%. In a series of three rats, we applied various electrochemical waveforms to platinum sites and monitored neural activity on adjacent iridium sites. We found that chronoamperometry and constant-potential amperometry did not alter firing rates at +0.25, +0.50, and +0.75 V. In addition, we have demonstrated multi-modal recordings of striatal neurons in response to medial forebrain bundle stimulation.

Exploiting changes in the tumour microenvironment with sequential cytokine and matrix metalloprotease inhibitor treatment in a murine breast cancer model

The study of treatment-induced changes in the tumour microenvironment might lead to effective combinations of biological therapy. IL-12 induced tumour regression and cure of an experimental murine breast cancer, HTH-K, but only after long-term treatment that was associated with chronic toxicity. During IL-12 therapy, tumour levels of the matrix metalloprotease MMP-9 declined and its inhibitor TIMP-1 was strongly induced. We therefore administered alternate cycles of IL-12 and the MMP inhibitor Batimastat (BB94) to mice. Therapeutic efficacy was increased compared with short-term IL-12 therapy but without the chronic toxicity associated with long-term IL-12 treatment. Image analysis of treated tumours revealed that BB94 prevented regeneration of tumour and stromal compartments that normally occurred after short-term IL-12 therapy.

A matrix metalloproteinase inhibitor which prevents fibroblast-mediated collagen lattice contraction

Matrix metalloproteinases (MMPs) and the specific tissue inhibitors of metalloproteinases (TIMPs) are involved in tissue turnover in normal and pathological processes including wound healing. Marimastat, a potent inhibitor of MMPs, was used to investigate the role of MMPs in an in vitro wound contraction model, the dermal equivalent, in which fibroblasts are grown in a collagen matrix. Marimastat inhibited fibroblast-mediated lattice contraction and this inhibition was reversible upon removal of the inhibitor, indicating that MMPs play an important role in fibroblast-mediated collagen lattice contraction, modelling what may happen when granulation tissue contracts in a healing wound.

Lack of cyclin E immunoreactivity in non-malignant breast and association with proliferation in breast cancer

Cyclin E is a G1 cyclin that is essential for the transition from G1 to S phase in the cell cycle. Alterations to cyclin E expression or regulation could be important in tumorigenesis. Previous immunohistochemical and immunoblotting studies have investigated the expression of cyclin E in breast carcinomas. In this study, cyclin E has been investigated in a range of non-malignant and malignant breast using immunohistochemistry. Normal and benign tissue from pre- and post-menopausal women (39 cases), non-involved tissue from cancer-containing breasts (47 cases), ductal carcinoma in situ (22 cases) and invasive breast carcinomas (109 cases) have been examined. There was no reactivity in any of the non-malignant breast. Only one ductal carcinoma in situ contained more than 5% reactive cells. A total of 28% of invasive carcinomas had > 5% of reactive cells (range 0-88% positive cells, mean 12.59%, median 1.0%). A significant association was found with poorer differentiation (P < 0.001), high MIB1 index (P < 0.001), lack of oestrogen receptor (0.05 > P > 0.025) and the presence of p53 protein (0.05 > P > 0.025). Virtually all cases with cyclin E and p53 were poorly differentiated. The presence of cyclin E is therefore only found in breast malignancies and is associated with more aggressive features, including high proliferation.

Hepatic adenosine triphosphate-dependent Ca2+ transport is mediated by distinct carriers on rat basolateral and canalicular membranes

To characterize and localize hepatic plasma membrane ATP-dependent Ca2+ transport and Na+/Ca2+ exchange, studies were performed using highly purified rat basolateral and canalicular membrane vesicles. ATP-dependent Ca2+ transport activity was present in vesicles from both domains, insensitive to azide, oligomycin, oxalate, calmodulin, and calmidazolium, and virtually abolished at pH 6.8. However, basolateral and canalicular transport differed significantly. While basolateral transport was markedly stimulated by 1 mM Mg2+, canalicular transport was Mg2+ independent. Basolateral transport was similar at pH 7.4 and 8.0 but canalicular activity was stimulated fourfold at pH 8.0. Both Ca2+ Km [1.4 +/- 0.1 (SE).10(-8) vs. 4.8 +/- 0.7.10(-8) M] and Vmax (3.6 +/- 0.1 vs. 9.0 +/- 0.6 nmol mg-1 protein min-1) were lower in basolateral than in canalicular vesicles. Basolateral transport was somewhat more nucleotide specific (for ATP) and sensitive to vanadate (IC50 130 vs. 500 microM, respectively) than was canalicular transport. Na+/Ca2+ exchange activity was not detected in membranes from either domain. These studies suggest that hepatic ATP-dependent Ca2+ transport is mediated by domain-specific carriers on the basolateral and canalicular membranes.

Estrogenic potencies of resorcylic acid lactones and 17 beta-estradiol in female rats

Uterotrophic response in sexually immature female rats has been used to rank the relative estrogenic potencies of six resorcylic acid lactones (RALs) and to compare their activities with that of 17 beta-estradiol. On oral administration, the estrogenic potency relative to 17 beta-estradiol is as follows: 7 alpha-zearalenol, 10 times less; zeranol, 150 times less; taleranol, 350 times less; zearalanone, 400 times less; zearalenone, 650 times less; 7 beta-zearalenol, 3500 times less. On subcutaneous administration, zeranol is 500 times less estrogenic than 17 beta-estradiol.

Hydroxyl/bile acid exchange. A new mechanism for the uphill transport of cholate by basolateral liver plasma membrane vesicles

In order to characterize the driving forces for the concentrative uptake of unconjugated bile acids by the hepatocyte, the effects of pH gradients on the uptake of [3H]cholate by rat basolateral liver plasma membrane vesicles were studied. In the presence of an outwardly directed hydroxyl gradient (pH 6.0 outside and pH 7.5 inside the vesicle), cholate uptake was markedly stimulated and the bile acid was transiently accumulated at a concentration 1.5- to 2-fold higher than at equilibrium ("overshoot"). In the absence of a pH gradient (pH 6.0 or 7.5 both inside and outside the vesicle), uptake was relatively slower and no overshoot was seen. Reductions in the magnitude of the transmembrane pH gradient were associated with slower initial uptake rates and smaller overshoots. Cholate uptake under pH gradient conditions was inhibited by furosemide and bumetanide but not by 4, 4'-diisothiocyano-2,2'-disulfonic stilbene (SITS), 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (DIDS), or probenecid. In the absence of a pH gradient, an inside-positive valinomycin-induced K+ diffusion potential caused a slight increase in cholate uptake which was insensitive to furosemide. Moreover, in the presence of an outwardly directed hydroxyl gradient, uphill cholate transport was observed even under voltage clamped conditions. These findings suggest that pH gradient-driven cholate uptake was not due to associated electrical potentials. Despite an identical pKa to that of cholate, an outwardly directed hydroxyl gradient did not drive uphill transport of three other unconjugated bile acids (deoxycholate, chenodeoxycholate, ursodeoxycholate), suggesting that a non-ionic diffusion mechanism cannot account for uphill cholate transport. In canalicular vesicles, although cholate uptake was relatively faster in the presence of a pH gradient than in the absence of a gradient, peak uptake was only slightly above that found at equilibrium under voltage clamped conditions. These findings suggest a specific carrier on the basolateral membrane of the hepatocyte which mediates hydroxyl/cholate exchange (or H+-cholate co-transport). A model for uphill cholate transport is discussed in which the Na+ pump would ultimately drive Na+/H+ exchange which in turn would drive hydroxyl/cholate exchange.