Frailty and poor physical functioning as risk factors for driving cessation

Introduction

Frailty and low physical performance are modifiable factors and, therefore, targets for interventions aimed at delaying driving cessation (DC). The objective was to determine the impact of frailty and physical performance on DC.

Methods

Multisite prospective cohort of older drivers. The key inclusion criteria are as follows: active driver age 65-79 years, possessing a valid driver's license, without significant cognitive impairment, and driving a 1996 car or a newer model car. Of the 2,990 enrolled participants, 2,986 (99.9%) had at least one frailty or Short Physical Performance Battery (SPPB) measure and were included in this study. In total, 42% of participants were aged 65-69 years, 86% were non-Hispanic white, 53% were female, 63% were married, and 41% had a high degree of education. The Fried Frailty Phenotype and the Expanded Short Physical Performance Battery (SPPB) from the National Health and Aging Trends Study were utilized. At each annual visit, DC was assessed by the participant notifying the study team or self-reporting after no driving activity for at least 30 days, verified via GPS. Cox proportional hazard models, including time-varying covariates, were used to examine the impact of the SPPB and frailty scores on time to DC. This assessment included examining interactions by sex.

Results

Seventy-three participants (2.4%) stopped driving by the end of year 5. Among women with a fair SPPB score, the adjusted hazard ratio (HR) of DC was 0.26 (95% confidence interval (CI) 0.10-0.65) compared to those with a poor SPPB score. For those with a good SPPB score, the adjusted HR of DC had a p-value of <0.001. Among men with a fair SPPB score, the adjusted hazard ratio (HR) of DC was 0.45 (95% CI 0.25-0.81) compared to those with a poor SPPB score. For men with a good SPPB score, the adjusted HR of DC was 0.19 (95% CI 0.10-0.36). Sex was not an effect modifier between frailty and DC. For those who were categorized into pre-frail or frail, the adjusted ratio of HR to DC was 6.1 (95% CI 2.7-13.8) compared to those who were not frail.

Conclusion and relevance

Frailty and poor physical functioning are major risk factors for driving cessation. Staying physically active may help older adults to extend their driving life expectancy and mobility.

Migraine headaches are associated with motor vehicle crashes and driving habits among older drivers: Prospective cohort study

BACKGROUND

Migraine headache is common in older adults, often causing symptoms that may affect driving safety. This study examined associations of migraine with motor vehicle crashes (MVCs) and driving habits in older drivers and assessed modification of associations by medication use.

METHODS

In a multi-site, prospective cohort study of active drivers aged 65-79 (53% female), we assessed prevalent migraine (i.e., ever had migraine, reported at enrollment), incident migraine (diagnosis first reported at a follow-up visit), and medications typically used for migraine prophylaxis and treatment. During 2-year follow-up, we recorded self-reported MVCs and measured driving habits using in-vehicle GPS devices. Associations of prevalent migraine with driving outcomes were estimated in multivariable mixed models. Using a matched design, associations of incident migraine with MVCs in the subsequent year were estimated with conditional logistic regression. Interactions between migraine and medications were tested in all models.

RESULTS

Of 2589 drivers, 324 (12.5%) reported prevalent migraine and 34 (1.3%) incident migraine. Interactions between migraine and medications were not statistically significant in any models. Prevalent migraine was not associated with MVCs in the subsequent 2 years (adjusted OR [aOR] = 0.98; 95% CI: 0.72, 1.35), whereas incident migraine significantly increased the odds of having an MVC within 1 year (aOR = 3.27; 1.21, 8.82). Prevalent migraine was associated with small reductions in driving days and trips per month and increases in hard braking events in adjusted models.

CONCLUSION

Our results suggest substantially increased likelihood of MVCs in the year after newly diagnosed migraine, indicating a potential need for driving safety interventions in these patients. We found little evidence for MVC risk or substantial changes in driving habits associated with prevalent migraine. Future research should examine timing, frequency, and severity of migraine diagnosis and symptoms, and use of medications specifically prescribed for migraine, in relation to driving outcomes.

A border health crisis at the United States-Mexico border: an urgent call to action

In this Viewpoint, we provide an overview of the worsening trend of traumatic injuries across the United States-Mexico border after its recent fortification and height extension to 30-feet. We further characterize the international factors driving migration and the current U.S. policies and political climate that will allow this public health crisis to progress. Finally, we provide recommendations involving prevention efforts, effective resource allocation, and advocacy that will start addressing the humanitarian and economic consequences of current U.S. border policies and infrastructure.

Impact of driving cessation on health-related quality of life trajectories

BACKGROUND

Trajectories of health-related quality of life (HRQoL) after driving cessation (DC) are thought to decline steeply, but for some, HRQoL may improve after DC. Our objective is to examine trajectories of HRQoL for individuals before and after DC. We hypothesize that for urban drivers, volunteers and those who access alternative transportation participants' health may remain unchanged or improve.

METHODS

This study uses data from the AAA Longitudinal Research on Aging Drivers (LongROAD) study, a prospective cohort of 2,990 older drivers (ages 65-79 at enrollment). The LongROAD study is a five-year multisite study and data collection ended October 31, 2022. Participants were recruited using a convenience sample from the health centers roster. The number of participants approached were 40,806 with 7.3% enrolling in the study. Sixty-one participants stopped driving permanently by year five and had data before and after DC. The PROMIS®-29 Adult Profile was utilized and includes: 1) Depression, 2) Anxiety, 3) Ability to Participate in Social Roles and Activities, 4) Physical Function, 5) Fatigue, 6) Pain Interference, 7) Sleep Disturbance, and 8) Numeric Pain Rating Scale. Adjusted (age, education and gender) individual growth models with 2989 participants with up to six observations from baseline to year 5 in the models (ranging from n = 15,041 to 15,300) were utilized.

RESULTS

Ability to participate in social roles and activities after DC improved overall. For those who volunteered, social roles and activities declined not supporting our hypothesis. For those who accessed alternative transportation, fatigue had an initial large increase immediately following DC thus not supporting our hypothesis. Urban residents had worse function and more symptoms after DC compared to rural residents (not supporting our hypothesis) except for social roles and activities that declined steeply (supporting our hypothesis).

CONCLUSIONS

Educating older adults that utilizing alternative transportation may cause initial fatigue after DC is recommended. Accessing alternative transportation to maintain social roles and activities is paramount for rural older adults after DC especially for older adults who like to volunteer.

Interaction between benzodiazepines and prescription opioids on incidence of hard braking events in older drivers

BACKGROUND

Polypharmacy use among older adults is of increasing concern for driving safety. This study assesses the individual and joint effects of benzodiazepines and prescription opioids on the incidence of hard braking events in older drivers.

METHODS

Data for this study came from the Longitudinal Research on Aging Drivers project-a multisite, prospective cohort study of 2990 drivers aged 65-79 years at enrollment (2015-2017). Adjusted incidence rate ratios (aIRRs) and 95% confidence intervals (CIs) of hard braking events (defined as maneuvers with deceleration rates ≥0.4 g and commonly known as near-crashes) were estimated through multivariable negative binominal modeling.

RESULTS

Of the 2929 drivers studied, 167 (5.7%) were taking benzodiazepines,  163 (5.6%) prescription opioids, and 23 (0.8%) both drugs at baseline. The incidence rates of hard braking events per 1000 miles driven were 1.14 (95% CI 1.10-1.18) for drivers using neither benzodiazepines nor prescription opioids, 1.25 (95% CI 1.07-1.43) for those using benzodiazepines only, 1.55 (95% CI 1.35-1.76) for those using prescription opioids only, and 1.63 (95% CI 1.11-2.16) for those using both medications. Multivariable modeling revealed that the use of prescription opioids was associated with a 19% increased risk of hard braking events (aIRR 1.19, 95% CI 1.03-1.36). There existed a positive interaction between the two drugs on the additive scale but not on the multiplicative scale.

CONCLUSION

Concurrent use of benzodiazepines and prescription opioids by older drivers appears to affect driving safety through increased incidence of hard braking events.

Motor Vehicle Crash Risk in Older Adult Drivers With Attention-Deficit/Hyperactivity Disorder

Importance

Symptoms of attention-deficit/hyperactivity disorder (ADHD), such as inattentiveness and impulsivity, could affect daily functioning and driving performance throughout the life span. Previous research on ADHD and driving safety is largely limited to adolescents and young adults.

Objective

To examine the prevalence of ADHD and the association between ADHD and crash risk among older adult drivers.

Design, Setting, and Participants

This prospective cohort study collected data from primary care clinics and residential communities in 5 US sites (Ann Arbor, Michigan; Baltimore, Maryland; Cooperstown, New York; Denver, Colorado; and San Diego, California) between July 6, 2015, and March 31, 2019. Participants were active drivers aged 65 to 79 years at baseline enrolled in the Longitudinal Research on Aging Drivers project who were studied for up to 44 months through in-vehicle data recording devices and annual assessments. The data analysis was performed between July 15, 2022, and August 14, 2023.

Exposure

Lifetime ADHD based on an affirmative response to the question of whether the participant had ever had ADHD or had ever been told by a physician or other health professional that he or she had ADHD.

Main Outcomes and Measures

The main outcomes were hard-braking events defined as maneuvers with deceleration rates of 0.4g or greater, self-reported traffic ticket events, and self-reported vehicular crashes. Multivariable negative binomial modeling was used to estimate adjusted incidence rate ratios (aIRRs) and 95% CIs of outcomes according to exposure status.

Results

Of the 2832 drivers studied, 1500 (53.0%) were women and 1332 (47.0%) were men with a mean (SD) age of 71 (4) years. The lifetime prevalence of ADHD in the study sample was 2.6%. Older adult drivers with ADHD had significantly higher incidence rates of hard-braking events per 1000 miles than those without ADHD (1.35 [95% CI, 1.30-1.41] vs 1.15 [95% CI, 1.14-1.16]), as well as self-reported traffic ticket events per 1 million miles (22.47 [95% CI, 16.06-31.45] vs 9.74 [95% CI, 8.99-10.55]) and self-reported vehicular crashes per 1 million miles (27.10 [95% CI, 19.95-36.80] vs 13.50 [95% CI, 12.61-14.46]). With adjustment for baseline characteristics, ADHD was associated with a significant 7% increased risk of hard-braking events (aIRR, 1.07; 95% CI, 1.02-1.12), a 102% increased risk of self-reported traffic ticket events (aIRR, 2.02; 95% CI, 1.42-2.88), and a 74% increased risk of self-reported vehicular crashes (aIRR, 1.74; 95% CI, 1.26-2.40).

Conclusions and Relevance

As observed in this prospective cohort study, older adult drivers with ADHD may be at a significantly elevated crash risk compared with their counterparts without ADHD. These findings suggest that effective interventions to improve the diagnosis and clinical management of ADHD among older adults are warranted to promote safe mobility and healthy aging.

Associations of cannabis use with motor vehicle crashes and traffic stops among older drivers: AAA LongROAD study

BACKGROUND

Acute cannabis use is associated with a higher risk of motor vehicle crashes (MVC). This study aimed to determine if self-reported past-year cannabis use is associated with MVC or traffic stops among older drivers.

METHODS

This cross-sectional analysis used data from a multi-center study enrolling active drivers aged 65-79 years. Data regarding cannabis use, MVC, and traffic stops (i.e., being pulled over by police, whether ticketed or not) within the previous 12 months were collected through participant interviews. Log-binomial regression models examined associations of past-year cannabis use with MVC and traffic stops, adjusting for site and sociodemographic and mental health characteristics.

RESULTS

Of 2,095 participating older drivers, 186 (8.88%) used cannabis in the past year but only 10 (<0.5%) within an hour before driving in the last 30 days; 11.41% reported an MVC and 9.45% reported a traffic stop. Past-year cannabis users had a higher prevalence of MVC (adjusted prevalence ratio [aPR] = 1.38; 95%CI: 0.96, 2.00; p = 0.086) and traffic stops (aPR = 1.58; 1.06, 2.35; p = 0.024).

CONCLUSIONS

Past-year cannabis use was associated with increased traffic stops, which are correlated modestly with increased MVC in past studies and may indicate impaired driving performance. We did not find a statistically significant association of past-year cannabis use with MVC, which may indicate limited sustained effects on driving performance from periodic use among older adults, who report rarely driving immediately after use.

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.

Impact of the COVID-19 Pandemic on Older Adult Driving in the United States

OBJECTIVES

To examine how the COVID-19 pandemic affected driving and health outcomes in older adults.

METHODS

We compared Advancing Understanding of Transportation Options (AUTO) study participants enrolled before (December 2019 to March 2020) versus during the pandemic (May 2020 to June 2021). Participants were English-speaking, licensed drivers (≥70 years) who drove weekly and had a primary care provider at a study site and ≥1 medical condition potentially associated with driving cessation. We used baseline self-reported measures on mobility and health.

RESULTS

Compared to those enrolled pre-COVID-19 (n = 61), more participants enrolled during COVID-19 (n = 240) reported driving reductions (26% vs. 70%, p < .001) and more often for personal preference (vs. medical/emotional reasons). While mean social isolation was higher during than pre-COVID-19, self-reported depression, stress, and overall health PROMIS scores did not differ significantly.

DISCUSSION

Our findings highlight the resiliency of some older adults and have implications for mitigating the negative effects of driving cessation.

"Is it time to stop driving?": A randomized clinical trial of an online decision aid for older drivers

BACKGROUND

Many older adults face the difficult decision of when to stop driving. We sought to test whether an online driving decision aid (DDA) would improve decision quality.

METHODS

This prospective two-arm randomized trial enrolled English-speaking licensed drivers (age ≥70 years) without significant cognitive impairment but with ≥1 diagnosis associated with increased likelihood of driving cessation; all participants received primary care in clinics associated with study sites in three states. The intervention was the online Healthwise® DDA for older adults addressing "Is it time to stop driving?"; control was web-based information for older drivers only. The primary outcome was decision conflict as estimated by the Decisional Conflict Scale (DCS; lower scores indicate higher quality). Secondary outcomes were knowledge and decision self-efficacy about driving decisions. We examined postrandomization differences in primary and secondary outcomes by study arm using generalized linear mixed-effects models with adjustment for site and prerandomization scores.

RESULTS

Among 301 participants (mean age: 77.1 years), 51.2% identified as female and the majority as non-Hispanic (99.0%) and white (95.3%); 98.0% lived in an urban area. Participant characteristics were similar by study arm but differed across sites. Intervention participants had a lower mean DCS score (12.3 DDA vs 15.2 control; adjusted mean ratio [AMR] 0.76, 95%CI 0.61-0.95; p = 0.017). Intervention participants had higher mean knowledge scores (88.9 DDA vs. 79.9 control; OR 1.13, 95%CI 1.01-1.27, p = 0.038); there was no difference between groups in self-efficacy scores. The DDA had high acceptability; 86.9% of those who viewed it said they would recommend it to others in similar situations.

CONCLUSIONS

The online Healthwise® DDA decreased decision conflict and increased knowledge in this sample of English-speaking, older adults without significant cognitive impairment, although most chose to continue driving. Use of such resources in clinical or community settings may support older adults as they transition from driving to other forms of mobility.

TRIAL REGISTRATION

ClinicalTrials.gov identifier "Advancing Understanding of Transportation Options (AUTO)" NCT04141891.

Rate of Social Isolation by Geographic Location Among Older Adults: AAA LongROAD Study

Introduction: Social isolation is a modifiable risk factor for negative health outcomes among older adults. This work assessed the relationship between geography (i.e., urban vs. non-urban residence) and social isolation in a cohort of older drivers.

Methods: The AAA LongROAD cohort with 2,989 older adult drivers from across the country were included. Social isolation was measured at baseline and at two subsequent annual follow-ups using PROMIS v2.0 Social Isolation 4a. The effect of geographic location with social isolation was assessed through with multivariable regression using a generalized estimating equation model.

Results: The rate of social isolation in urban areas was 21% lower (adjusted RR 0.79, 95% CI 0.46, 1.36) compared to non-urban areas after adjusting for covariates, though not significant.

Discussion: Social isolation is a predictor of poor health outcomes and geographic considerations have been lacking in the literature. The panel data in this analysis provides more evidence for causality though the under-representation of non-urban areas potentially reduces the power for the results.

Conclusions: It is important to understand the needs and risk of social isolation in various geographic settings to ensure resources and interventions are appropriately modified for a greater public health impact.

Potentially Inappropriate Medication Use and Hard Braking Events in Older Drivers

Potentially inappropriate medications (PIMs) identified by the American Geriatrics Society should generally be avoided by older adults because of ineffectiveness or excess risk of adverse effects. Few studies have examined the effects of PIMs on driving safety measured by prospectively and objectively collected driving data. Data for this study came from the Longitudinal Research on Aging Drivers study, a multisite naturalistic driving study of older adults. Multivariable negative binominal modeling was used to estimate incidence rate ratios and 95% confidence intervals of hard braking events (proxies for unsafe driving behavior defined as events with a deceleration rate ≥0.4 g) associated with PIM use among older drivers. The study sample consisted of 2932 drivers aged 65-79 years at baseline, including 542 (18.5%) who used at least one PIM. These drivers were followed through an in-vehicle recording device for up to 44 months. The overall incidence of hard braking events was 1.16 per 1000 miles. Use of PIMs was associated with a 10% increased risk of hard braking events. Compared to drivers who were not using PIMs, the risk of hard braking events increased 6% for those using one PIM, and 24% for those using two or more PIMs. Use of PIMs by older adult drivers is associated in a dose-response fashion with elevated risks of hard braking events. Reducing PIM use in older adults might help improve driving safety as well as health outcomes.

Medication use and driving patterns in older drivers: preliminary findings from the LongROAD study

Background

The potential for impaired driving due to medication use can occur at any age, though older adults are more likely to take multiple prescribed medications and experience side effects that may affect driving ability. The purpose of this study was to characterize the relationship between medications and driving safety behaviors.

Methods

Data for this study came from the five-site Longitudinal Research on Aging Drivers (LongROAD) project. Participants were active drivers, age 65–79 years at enrollment, and patients at one of the 5 participating sites. Medication names and doses were obtained at baseline based on the “brown-bag review” method. Medications were coded using the American Hospital Formulary Service system. Driving data were collected by a GPS accelerometer installed in the study participants’ main vehicles.

Results

Medication data were available for 2949 (98.6%) of the 2990 participants, and 2898 (96.9% of all participants) had both medication data and at least 30 recorded days of driving. The median number of medications taken per study participant was seven, with a range of 0–51. Total number of medications was significantly associated with a higher rapid deceleration rate. Certain medication classes were significantly associated with other driving outcomes, including central nervous system agents (more speeding events), hormones and gastrointestinal medications (more rapid decelerations), electrolytes (fewer rapid decelerations), and antihistamines (greater right to left turn ratio).

Conclusions

Older adult drivers are taking large quantities of prescription and non-prescription medications that may affect their driving safety. Certain medication classes are associated with potentially adverse driving patterns, such as speeding and rapid decelerations, while others are associated with potentially protective maneuvers, such as right hand turning. Further research is warranted to identify and mitigate potential adverse effects of such medications on driving safety in older adults.

Prevalence of Potentially Inappropriate Medication use in older drivers

Background

Potentially Inappropriate Medication (PIM) use has been studied in a variety of older adult populations across the world. We sought to examine the prevalence and correlates of PIM use in older drivers.

Methods

We applied the American Geriatrics Society 2015 Beers Criteria to baseline data collected from the “brown-bag” review of medications for participants of the Longitudinal Research on Aging Drivers (LongROAD) study to examine the prevalence and correlates of PIM use in a geographically diverse, community-dwelling sample of older drivers (n = 2949). Proportions of participants who used one or more PIMs according to the American Geriatrics Society 2015 Beers Criteria, and estimated odds ratios (ORs) and 95% confidence intervals (CIs) of PIM use associated with participant characteristics were calculated.

Results

Overall, 18.5% of the older drivers studied used one or more PIM. The most commonly used therapeutic category of PIM was benzodiazepines (accounting for 16.6% of the total PIMs identified), followed by nonbenzodiazepine hypnotics (15.2%), antidepressants (15.2%), and first-generation antihistamines (10.5%). Compared to older drivers on four or fewer medications, the adjusted ORs of PIM use were 2.43 (95% CI 1.68–3.51) for those on 5–7 medications, 4.19 (95% CI 2.95–5.93) for those on 8–11 medications, and 8.01 (95% CI 5.71–11.23) for those on ≥12 medications. Older drivers who were female, white, or living in urban areas were at significantly heightened risk of PIM use.

Conclusion

About one in five older drivers uses PIMs. Commonly used PIMs are medications known to impair driving ability and increase crash risk. Implementation of evidence-based interventions to reduce PIM use in older drivers may confer both health and safety benefits.

Trial registration

Not applicable.

Relationship Between Physical Activity and Motor Vehicle Crashes Among Older Adult Drivers

Background: There are approximately 42 million licensed drivers aged 65 years or older in the United States, who face unique age-related risks while driving. While physical activity affects several chronic conditions thought to be associated with motor vehicle crashes (MVCs), it is unclear if increased physical activity leads to fewer MVCs. This study explores whether self-reported vigorous and moderate physical activity is associated with MVCs in the previous year. Methods: Using cross-sectional data from the LongROAD study, a large multisite prospective cohort study of 2990 older adult drivers, we examined variables related to physical activity and performed a multivariate regression analysis to examine the association of physical activity health behaviors with self-reported MVCs. Results: Overall, 41.2% of participants reported vigorous and 69.6% of participants reported moderate exercise at least once per week. Eleven percent of participants reported at least 1 MVC in the previous year. Neither vigorous nor moderate physical activity was significantly associated with self-reported MVCs in the previous year. Select variables that were significantly associated with self-reported MVC included self-reported unsafe driving practices (odds ratio [OR] 1.55, confidence interval [CI] 1.05-2.29), and fall in the past 12 months (OR 1.46, CI 1.14-1.85). Conclusions: We were unable to detect a significant association between self-reported physical activity and MVCs in the past year among this group of older drivers. Use of objective measures of activity may better clarify this relationship.

Patterns of Self-Reported Driving While Intoxicated Among Older Adults

Objective: This study examines the prevalence of self-reported driving while intoxicated (DWI) among drivers aged 65 and older. Method: This cross-sectional study was based on baseline data from the AAA Longitudinal Research on Aging Drivers (LongROAD) study, a multisite prospective cohort study of 2,990 older adult drivers. Alcohol-related variables from the baseline questionnaire were examined in relation to demographics, health status, and driving behaviors. A logistic regression model assessed variables associated with DWI. Results: Of the 2,990 participants, 72.7% reported consuming alcohol, 15.0% reported high-risk drinking, and 3.3% reported DWI. High-risk drinking (OR = 12.01) and risky driving behaviors (OR = 13.34) were significantly associated with at least occasional DWI. Avoidance of hazardous driving conditions (OR = 0.71) and higher level of comfort during challenging driving scenarios (OR = 0.65) were less likely to be associated with DWI. Conclusion: A large number of older adults engage in high-risk drinking and DWI. Public health education and DWI-related interventions should include older adults.

Mobile Telephone Use and Reaction Time in Drivers With Glaucoma

IMPORTANCE

Combining mobile telephone use with driving is not unusual. However, distracted driving limits driving performance because of limited capacity for persons to divide attention.

OBJECTIVES

To investigate the frequency of mobile telephone use while driving and to assess whether patients with glaucoma had a disproportionate decrease in driving performance while conversing on a mobile telephone compared with healthy participants.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of surveys collected from 112 patients with glaucoma and 70 control participants investigating mobile telephone use while driving. A randomly selected subgroup of 37 patients with glaucoma and 28 controls drove in a driving simulator to investigate peripheral event detection performance during distracted driving at the Visual Performance Laboratory, Duke University, Durham, North Carolina. Data collection was performed from December 1, 2016, through April 30, 2017.

EXPOSURES

Participants answered a survey and submitted to a driving simulation test with and without mobile telephone use.

MAIN OUTCOMES AND MEASURES

Survey answers were collected, and distracted driving performance, assessed by reaction time to peripheral stimuli, was analyzed.

RESULTS

Of the 182 participants who answered the survey, the 112 participants with glaucoma included 56 women (50.0%) and had a mean (SD) age of 73.6 (9.6) years. The 70 controls included 49 women (70.0%) and had a mean (SD) age of 68.4 (10.9) years. When asked about mobile telephone use while driving, 30 patients with glaucoma (26.8%) admitted rarely using and 2 (1.8%) sometimes using it. In the control group, 20 participants (28.6%) admitted rarely using and 2 (2.9%) sometimes using the telephone while driving (P = .80). Reaction times to peripheral stimuli were significantly longer among patients with glaucoma compared with controls during mobile telephone use (median [interquartile range], 1.86 [1.42-2.29] seconds vs 1.14 [0.98-1.59] seconds; P = .02). Compared with driving performance while not using a mobile telephone, the mean (SD) increase of 0.85 (0.60) second in reaction time while conversing on the mobile telephone among patients with glaucoma was significantly greater than the mean (SD) increase of 0.68 (0.83) second for controls (P = .03).

CONCLUSIONS AND RELEVANCE

This study's findings indicate that patients with glaucoma use mobile telephones while driving as frequently as healthy participants. However, the findings also suggest that patients with glaucoma may experience a greater decline than healthy participants in their ability to detect peripheral events while driving when also talking on a mobile telephone. Patients with glaucoma should be informed that they may have a higher driving risk that may be worsened by distractions, such as mobile telephone use.

Longitudinal Research on Aging Drivers (LongROAD): study design and methods

BACKGROUND

As an important indicator of mobility, driving confers a host of social and health benefits to older adults. Despite the importance of safe mobility as the population ages, longitudinal data are lacking about the natural history and determinants of driving safety in older adults.

METHODS

The Longitudinal Research on Aging Drivers (LongROAD) project is a multisite prospective cohort study designed to generate empirical data for understanding the role of medical, behavioral, environmental and technological factors in driving safety during the process of aging.

RESULTS

A total of 2990 active drivers aged 65-79 years at baseline have been recruited through primary care clinics or health care systems in five study sites located in California, Colorado, Maryland, Michigan, and New York. Consented participants were assessed at baseline with standardized research protocols and instruments, including vehicle inspection, functional performance tests, and "brown-bag review" of medications. The primary vehicle of each participant was instrumented with a small data collection device that records detailed driving data whenever the vehicle is operating and detects when a participant is driving. Annual follow-up is being conducted for up to three years with a telephone questionnaire at 12 and 36 months and in-person assessment at 24 months. Medical records are reviewed annually to collect information on clinical diagnoses and healthcare utilization. Driving records, including crashes and violations, are collected annually from state motor vehicle departments. Pilot testing was conducted on 56 volunteers during March-May 2015. Recruitment and enrollment were completed between July 2015 and March 2017.

CONCLUSIONS

Results of the LongROAD project will generate much-needed evidence for formulating public policy and developing intervention programs to maintain safe mobility while ensuring well-being for older adults.

Depression, antidepressants and driving safety

BACKGROUND

The purpose of this study was to review to review the reported associations of depression and antidepressants with motor vehicle crashes.

PURPOSE

A literature search for material published in the English language between January, 1995, and October, 2015, in bibliographic databases was combined with a search for other relevant material referenced in the retrieved articles.

METHODS

Retrieved articles were systematically reviewed for inclusion criteria: 19 epidemiological studies (17 case-control and 2 cohort studies) fulfilled the inclusion criteria by estimating the crash risk associated with depression and/or psychotropic medications in naturalistic settings.

RESULTS

The estimates of the odds ratio (OR) of crash involvement associated with depression ranged from 1.78 to 3.99. All classes of antidepressants were reported to have side effects with the potential to affect driving safety. The majority of studies of antidepressant effects on driving reported an elevated crash risk, and ORs ranged from 1.19 to 2.03 for all crashes, and 3.19 for fatal crashes. In meta-analysis, depression was associated with approximately 2-fold increased crash risk (summary OR = 1.90; 95% CI, 1.06 to 3.39), and antidepressants were associated with approximately 40% increased crash risk (summary OR = 1.40; 95%CI, 1.18 to 1.66).

CONCLUSION

Based on the findings of the studies reviewed, depression, antidepressants or the combination of depression and antidepressants may pose a potential hazard to driving safety. More research is needed to understand the individual contributions of depression and the medications used to treat depression.

Associations Between Health and Driving in an Older Adult Cohort in Rancho Bernardo

OBJECTIVE

The purpose of this study was to identify the associations between health and health care utilization with driving patterns in a cohort of older adults.

METHOD

In 2012, a total of 1,826 surviving participants in the Rancho Bernardo cohort were sent a health and driving pattern survey; 1,277 were returned.

RESULTS

The majority of the respondents (1,151, 91%) were still driving. Older age, female sex, hospitalizations, emergency department (ED) visits and physical therapy visits, neurological disease, depression, limited vision, and limited hearing were associated with non-driving status. A total of 809 (71%) of drivers reported no citations or crashes in the last 5 years.

DISCUSSION

The vast majority of older drivers in this cohort continued to drive, and did so safely. Health care utilization, medications, medical conditions, and self-assessment of health were associated with non-driving status. Prospective studies are needed to clarify the temporal relationships between these factors.

Development of a curriculum and roadside screening tool for Law enforcement identification of medical impairment in aging drivers

Background

An estimated one in five drivers will be over 65 by 2030. Compared with their younger counterparts, older adults are more likely to experience health and functional impairments, including cognitive dysfunction, which may interfere with their ability to drive safely. Law enforcement officers, as part of the public safety community, need help in developing the necessary skills to identify and manage these medically affected drivers.

Methods

To address this need, in partnership with the California Highway Patrol (CHP), Training, Research and Education for Driving Safety (TREDS) at the University of California, San Diego, developed a certified two-hour training curriculum. To complement the training, the TREDS team also developed a roadside screening tool to assess for disorientation related to person, place, and time. The tool was developed, validated with a sample of persons with dementia compared to cognitively normal controls, and deployed in the training. A total of 2,018 police officers received instruction at 103 training sessions.

Results

At baseline, prior to training, only 26 % of officers had reported drivers to the Department of Motor Vehicles in the previous 6 months. After training, 96 % stated they were likely to use their standard reporting forms, and 90 % reported they were likely to use the roadside screening tool.

Conclusions

The certified training and tool were well received and resulted in changes to knowledge, attitudes, and intention to incorporate their new knowledge and tools into roadside screening.

Training on Exercise is Medicine® Within an Integrative Medicine Curriculum

Physicians are increasingly approached by individuals seeking integrative approaches to health care and well-being. Many integrative modalities include a physical activity component. Patients seek guidance from primary and specialty care providers on the safe and effective incorporation of these modalities into their lifestyle. Physicians and other health professionals receive very limited training in the clinical applications of exercise science. This paper reports on a curriculum designed to teach health professionals key exercise constructs for application to clinical practice for prevention and management of lifestyle-related disease, and incorporating the curriculum into a preventive medicine residency training program. The course was developed in 2012-2013, data collected in 2013-2015, and analysis was done in 2015. Six modules were developed as part of a 24-hour course. Each module included didactic, laboratory, and case examples. The modules included energetics, exercise and cardiorespiratory health, bone health, obesity and sarcopenia, balance and fall prevention, and behavior change and the use of technologies. The delivery was found feasible for all three components, delivered in 2-4-hour segments. The incorporation into the residency curriculum was feasible, efficacious, well received, and easily incorporated into the existing curriculum. This comprehensive curriculum has the potential to close the gap in medical school, residency, graduate, nursing, and integrative curricula on this important topic. Current practitioners would benefit in primary care and geriatric settings. This curriculum would also be useful for cross-disciplinary researchers, including public health, health behaviors, and integrative medicine practitioners.

Evaluation of curriculum to improve health professionals' ability to manage age-related driving impairments

As our elderly population increases in proportion with respect to the rest of society, age-related driving impairments are increasing in importance as a public health concern. In this context, health professionals play an important role in identifying impaired drivers. This situation is complicated for two reasons: discussion of driving cessation is a sensitive topic for both health professionals and the elderly, and physicians have limited familiarity with the current American Medical Association (AMA) screening guidelines or mandated reporting laws. To assess curriculum that trains health professionals to increase their awareness, screening, management, and reporting of age-related driving impairments. Between 2009 and September 2011, 47 trainings were delivered to 1202 health professionals. The majority of trainings were seminars or lectures lasting 1h; all were conducted in southern California. The training curriculum was divided into four sections: introduction and background; screening and interpretation; managing outcomes and reporting; and referrals and resources. Videos addressed broaching the topic with patients and counseling on driving cessation. The curriculum was delivered by physicians with the support of public health-trained program staff. Pre- and post-testing was done with 641 of the participants; the majority were physicians. Post-training, participants' confidence in ability to screen increased to 72% and intent to screen increased to 55%. Fully 92% stated they had developed a better understanding of California's mandated reporting laws. Similarly, 92% said they had developed a better understanding of the medical conditions and medications that may impair older adults' ability to drive safely. Furthermore, 91% said mandated-reporting laws helped protect the safety of patients and others, and 59% said it was easier to discuss and justify driving cessation with patients. In-person training of health professionals on age-related driving impairments was well received and resulted in increased self-reported knowledge, confidence to screen, and intent to screen. Physicians were supportive of mandatory reporting laws.

Gaps between Adolescent Risk Behaviors and Disclosure during Outpatient Visits

Objective. The purpose of this study was to determine the gaps between disclosed high-risk behaviors in low-income, mainly Hispanic youth and the identification of these risks by health care providers. Methods. This cross-sectional study included youth 13-19 years old who participated in a study on latent tuberculosis treatment. Youth were interviewed at baseline by bilingual research assistants; the provider visit was assessed by the chart review. Results. Of 221 youth, the majority (96%) were identified as Hispanic, 45% were foreign-born, and 46% were male. A total of 399 risk behaviors were revealed to research staff by the participants; only 24 risk behaviors were revealed to providers. Conclusions. The majority of risk behaviors based on the chart review were neither queried nor disclosed to the physicians. Physicians providing care to adolescents should consider strategies to improve disclosure as a necessary precursor to interventions.

The U.S.-Mexico border: a time-trend analysis of border-crossing injuries

BACKGROUND

Policies over the past 15 years have resulted in changes to the physical border between the U.S. and Mexico, as well as increases in the number of border patrol agents.

PURPOSE

The purpose of this study is to characterize the trends and epidemiology of physically traumatic border-crossing injuries sustained over an 8-year period in San Diego County.

METHODS

This is a time-series study using existing data collected by the University of California, San Diego Level 1 Trauma Center between 2000 and 2007. This study includes data for individuals traumatically injured owing to a jump or fall in an attempt to cross over the border fence. Time-trend analysis was conducted using Poisson regression. A multiple linear regression was conducted to determine whether there was an increase in the severity of injuries to border crossers between 2000 and 2007.

RESULTS

Analysis demonstrated a significant increase in the number of those injured each year specifically as a result of jumping or falling from the border fence, from 13 in 2000 to 52 in 2007, even though there was a decrease in the number of apprehensions for illegal entry into the U.S. On average, each year, the injury severity decreased by 0.38 between the years 2000 and 2007.

CONCLUSIONS

Jumping and falling injuries at the San Diego-Mexico border increased during a time when apprehensions were decreasing. Further studies are needed to identify strategies to mitigate this problem.

Improving physician involvement in care management programs

Care management delivered by interdisciplinary teams has been demonstrated to be a successful method for treating diseases such as asthma, hypertension, diabetes, and heart failure. Two models have emerged: (1) office-based programs, in which most services are delivered directly from the practice; and (2) insurer-run or purchased (external) programs delivered by third parties. Physician involvement and coordination of patient care with both programs is felt to be advantageous, yet physician involvement has been found to be sporadic. The issues surrounding physician noninvolvement have not been delineated, as the few studies conducted have tended to be descriptive, and they have not provided a model that could inform policy makers how to improve collaborative relationships. The purpose of this study was to construct such a model.

Significant injury in cruise ship passengers a case series

BACKGROUND

The attention placed on cruise ship infectious epidemics has helped create important preventive strategies in improving food handling, sanitation, and overall cruise ship medical care. However, the incidence of serious injury in cruise ship passengers has never been fully described. In 2006, there was an increase in the number of cruise ship passengers receiving medical care at a Level I trauma center. This report provides a case series analysis of eight patients identified as suffering from significant cruise ship-related injuries.

METHODS

A retrospective, descriptive study design was used. Data on trauma patients transported directly from cruise ships and admitted to a university Level I trauma center in 2003-2006 were reviewed.

RESULTS

A total of 2,132 patients were admitted as major trauma resuscitations in 2006. Eight were identified as being injured on a major cruise ship compared to an average of 1.7 patients/year in the preceding 3 years. All but one patient was female. Three patients had significant medical comorbidities. All eight patients suffered injuries from falls, five of which were in stairwells. Concussions were the most common injury. Five patients were discharged to home, two to extended rehabilitation facilities, and one died.

CONCLUSIONS

In this case series, falls were the sole cause of major injury among cruise ship passengers. Improved surveillance and characterization of injuries among cruise ship passengers is needed to inform safety policies and develop programs to prevent passenger injury.

Echinacea purpurea supplementation stimulates select groups of human gastrointestinal tract microbiota

BACKGROUND AND OBJECTIVE

The objective of this research was to determine the effects of the dietary supplement Echinacea purpurea on aerobic and anaerobic bacteria common to the human gastrointestinal (GI) tract. Botanical extracts have shown in vitro antimicrobial effects against certain pathogenic bacteria. It is uncertain if medicinal herbs have any effect against pathogenic bacteria or on the native GI microbiota.

METHODS

Fifteen human subjects consumed 1000 mg of standardized E. purpurea for 10 days. Faecal samples were collected at baseline, 10 days and 17-18 days following supplementation. Samples were tested for select aerobic and anaerobic bacteria using plate culture microbiological methods.

RESULTS AND DISCUSSION

Significant increases were found for total aerobic bacteria, Bacteroides group and Bacteroides fragilis after E. purpurea exposure. Supplementation did not significantly alter the number of enteric bacteria, enterococci, lactobacilli, bifidobacteria or total anaerobic bacteria.

CONCLUSION

Echinacea supplementation has altered the GI microbiota. The health consequences associated with this change are unknown but previous research has shown increased Bacteroides concentrations associated with diarrhoea, inflammatory bowel disease and increased risk of colon cancer. Additional research should delineate the role of Echinacea in the stimulation of Bacteroides and describe the effects of other botanical supplements to the GI microbiota.

The journey to wellness: stages of refugee health promotion and disease prevention

Refugees experience a threefold challenge to their health and well-being: 1) psychiatric disorders precipitated by the refugee experience, 2) infectious and parasitic diseases endemic to countries of origin, and 3) chronic diseases endemic to host countries. This paper documents the "journey to wellness" in which these challenges are faced in stages by the refugees themselves and by the array of health and social service agencies committed to providing refugee assistance. Using the experience of a consortium of agencies in San Diego as an example, we examine the interaction between these challenges and the mobilization of organizations to develop a program of health promotion and disease prevention for Somali and other East African refugees. This mobilization involves a series of steps designed to facilitate refugee confidence, comprehension, and compliance with prevention efforts through community-provider partnerships and negotiation between refugee and organizational explanatory models of disease causation and prevention.

Loss of Fas-ligand expression in mouse keratinocytes during UV carcinogenesis

Skin cells containing excessive ultraviolet (UV) radiation-induced DNA damage are eliminated by apoptosis that involves the p53 pathway and Fas/Fas-Ligand (Fas-L) interactions. To determine whether dysregulation of apoptosis plays a role in skin cancer development through disruption of Fas/Fas-L interactions, hairless SKH-hr1 mice were exposed to chronic UV irradiation from Kodacel-filtered FS40 lamps for 30 weeks. Their skin was analyzed for the presence of sunburn cells (apoptotic keratinocytes) and for Fas and Fas-L expression at various time points. A dramatic decrease in the numbers of morphologically identified sunburn cells and TUNEL-positive cells was detected as early as 1 week after chronic UV exposure began. After 4 weeks of chronic UV exposure, these cells were barely detectable. This defect in apoptosis was paralleled by an initial decrease in Fas-L expression during the first week of chronic UV irradiation and a complete loss of expression after 4 weeks. Fas expression, however, increased during the course of chronic UV exposure. p53 mutations were detected in the UV-irradiated epidermis as early as 1 week after irradiation began and continued to accumulate with further UV exposure. Mice exposed to chronic UV began to develop skin tumors after approximately 8 weeks, and all mice had multiple skin tumors by 24 weeks. Most of the tumors expressed Fas but not Fas-L. We conclude that chronic UV exposure may induce a loss of Fas-L expression and a gain in p53 mutations, leading to dysregulation of apoptosis, expansion of mutated keratinocytes, and initiation of skin cancer.

Fas and Fas ligand interactions in malignant disease

Apoptosis has been implicated in tumor development and progression. Fas (CD95) and Fas ligand (FasL) are an interacting receptor ligand pair that elicits apoptosis in many cell types. Although originally described as proteins regulating peripheral immune tolerance, accumulating evidence suggests that Fas/FasL may play an important role in carcinogenesis, tumor outgrowth, and metastasis. This review summarizes our current knowledge about the regulation of Fas and FasL expression, Fas signaling, soluble Fas production, the role(s) of Fas and FasL in hematopoietic and non-hematopoietic tumorigenesis and progression, and the potential application of Fas-induced apoptosis in cancer therapy.

Combined therapy with zaprinast and inhaled nitric oxide abolishes hypoxic pulmonary hypertension

OBJECTIVE

To determine whether the combination of the phosphodiesterase 5 inhibitor zaprinast and inhaled nitric oxide (NO) decreases hypoxic pulmonary hypertension in the rat.

DESIGN

Prospective, experimental study.

SETTING

Animal laboratory of a university medical center.

SUBJECTS

Male Sprague-Dawley rats.

INTERVENTIONS

Anesthetized rats were mechanically ventilated and instrumented for measurement of mean systemic arterial pressure, pulmonary arterial pressure, and cardiac output. In group 1, four acute hypoxic challenges (FIO2 = 0.17 for 5 mins) were performed: initial, during 40 ppm inhaled NO, immediately after discontinuation of 5 mins of inhaled NO, and final. In group 2 rats, an initial hypoxic challenge was performed and rats then received zaprinast (3 mg/kg bolus followed by 0.3 mg/kg/min infusion). Four hypoxic challenges analogous to group 1 were then performed during zaprinast administration.

MEASUREMENTS AND MAIN RESULTS

Initial hypoxic challenge produced similar increases in pulmonary arterial pressure in both groups. In group 1, inhaled NO either only before or only during hypoxia decreased the pulmonary hypertensive response to hypoxia. In group 2, zaprinast administration did not alter hemodynamics. Zaprinast alone decreased the pulmonary hypertensive response to hypoxia. The combination of zaprinast and inhaled NO (either before or during hypoxia) abolished the pulmonary hypertensive response to hypoxia.

CONCLUSIONS

Treatment with inhaled NO for 5 mins before but not during hypoxia is as effective as inhaled NO during hypoxia. Inhaled NO and zaprinast both decrease the pulmonary hypertensive response to hypoxia, and the combination abolishes the response. The combination of a phosphodiesterase 5 inhibitor and inhaled NO may have clinical applicability in the treatment of pulmonary hypertension.

Apoptosis in mycobacterium tuberculosis infection in mice exhibiting varied immunopathology

This study examined mechanisms contributing to pulmonary immunopathology following acute Mycobacterium tuberculosis (MTB) infection in vivo in a murine model. A/J and C57BL/6 mice were intravenously infected with MTB (Erdman). Pathological differences were found between strains, unrelated to pulmonary load of bacilli. A/J mice developed progressive interstitial pneumonitis, while C57BL/6 mice maintained granuloma formation. The contribution of FAS and FAS ligand-mediated apoptosis was assessed via bioluminescent reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemical staining, and TUNEL assessment of DNA fragmentation. Cytokine messages for pulmonary tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), as well as for the lytic molecules perforin and granzyme B, were quantified. Immunohistochemical staining for CD3 receptor was performed to monitor lymphocytic lung infiltration. Soon after infection, A/J mice exhibited increased pulmonary IFN-gamma message, concurrent with the appearance of CD3+ lymphocytes distributed throughout the lung. C57BL/6 mice exhibited perivascular cuffing, with no accompanying increase in IFN-gamma message. A/J mice also had elevated levels of FAS and FAS ligand message and protein early after infection, while the C57BL/6 mice had no increased expression of these molecules. Both strains exhibited qualitatively similar numbers of TUNEL-positive cells throughout infection, with a marked increase on day 7. Apoptotic cells appeared to co-localize with acid fast bacilli. It is therefore proposed that apoptosis during initial granuloma formation following MTB infection may occur through a FAS/FAS ligand-independent pathway. Moreover, a failure of completion of the FAS/FAS ligand-mediated apoptosis pathway in the A/J mice may contribute to inefficient elimination of lymphocytes, thus further aggravating pulmonary pathology.

Fas ligand: a sensor for DNA damage critical in skin cancer etiology

DNA-damaged cells can either repair the DNA or be eliminated through a homeostatic control mechanism termed "cellular proofreading." Elimination of DNA-damaged cells after ultraviolet radiation (UVR) through sunburn cell (apoptotic keratinocyte) formation is thought to be pivotal for the removal of precancerous skin cells. Sunburn cell formation was found to be dependent on Fas ligand (FasL), a pro-apoptotic protein induced by DNA damage. Chronic exposure to UVR caused 14 of 20 (70 percent) FasL-deficient mice and 1 of 20 (5 percent) wild-type mice to accumulate p53 mutations in the epidermis. Thus, FasL-mediated apoptosis is important for skin homeostasis, suggesting that the dysregulation of Fas-FasL interactions may be central to the development of skin cancer.

A critical role for Fas ligand in the active suppression of systemic immune responses by ultraviolet radiation

Induction of antigen-specific suppression elicited by environmental insults, such as ultraviolet (UV)-B radiation in sunlight, can inhibit an effective immune response in vivo and may contribute to the outgrowth of UV-induced skin cancer. Although UV-induced DNA damage is known to be an initiating event in the immune suppression of most antigen responses, the underlying mechanism(s) of such suppression remain undefined. In this report, we document that Fas ligand (FasL) is critical for UV-induced systemic immune suppression. Normal mice acutely exposed to UV exhibit a profound suppression of both contact hypersensitivity and delayed type hypersensitivity (DTH) reactions and the development of transferable antigen-specific suppressor cells. FasL-deficient mice exposed to UV lack both transferable suppressor cell activity and primary suppression to all antigens tested, with the exception of the DTH response to allogeneic spleen cells. Interestingly, suppression of this response is also known to occur independently of UV-induced DNA damage. Delivery of alloantigen as protein, rather than intact cells, restored the requirement for FasL in UV-induced immune suppression of this response. These results substantiate that FasL/Fas interactions are essential for systemic UV-induced suppression of immune responses that involve host antigen presentation and suggest an interrelationship between UV-induced DNA damage and FasL in this phenomenon. Collectively, our results suggest a model whereby UV-induced DNA damage disarms the immune system in a manner similar to that observed in immunologically privileged sites.

Combined inhaled nitric oxide and inhaled prostacyclin during experimental chronic pulmonary hypertension

Inhaled nitric oxide (NO) and inhaled prostacyclin (PGI2) produce selective reductions in pulmonary vascular resistance (PVR) through differing mechanisms. NO decreases PVR via cGMP, and PGI2 produces pulmonary vasodilation via cAMP. As a general pharmacological principle, two drugs that produce similar effects via different mechanisms should have additive or synergistic effects when combined. We designed this study to investigate whether combined inhaled NO and PGI2 therapy results in additive effects during chronic pulmonary hypertension in the rat. Monocrotaline injected 4 wk before study produced pulmonary hypertension in all animals. Inhaled NO (20 parts/million) reversibly and selectively decreased pulmonary artery pressure (Ppa) with a mean reduction of 18%. Four concentrations of PGI2 were administered via inhalation (5, 10, 20, and 80 microg/ml), both alone and combined with inhaled NO. Inhaled PGI2 alone decreased Ppa in a dose-dependent manner with no change in mean systemic arterial pressure. Combined inhaled NO and PGI2 selectively and significantly decreased Ppa more did than either drug alone. The effects were additive at the lower concentrations of PGI2 (5, 10, and 20 microg/ml). The combination of inhaled NO and inhaled PGI2 may be useful in the management of pulmonary hypertension.

Fas and Fas ligand interactions suppress melanoma lung metastasis

Apoptosis induced by Fas (CD95) ligation is frequently lost during tumor progression; however, there is no direct evidence to support an association of Fas loss-of-function with metastatic tumor behavior. To determine whether Fas loss-of-function is critical for acquisition of the metastatic phenotype, we have compared the ability of Fas-sensitive K1735 murine melanomas to form spontaneous lung metastases in wild-type and Fas ligand-deficient mice. Fas-sensitive melanoma clones are highly tumorigenic but rarely metastatic in wild-type syngeneic mice. However, in Fas ligand-deficient mice, both the incidence and number of metastases are increased. These findings provide the first evidence that Fas-Fas ligand interactions can suppress metastasis and that tumor Fas loss-of-function may be causally linked to metastatic progression.