Road-traffic deaths in China, 1985-2005: threat and opportunity.

OBJECTIVE: To examine recent trends and geographic variations in road-traffic deaths in China. DESIGN: A longitudinal descriptive analysis of national and provincial data on road-traffic deaths, examining recent trends and geographic variations. SETTING: China, 1985-2005. DATA SOURCES: The Transportation and communications yearbook of China (1986-2006) and the National statistics yearbook of China (1996-2006). MAIN OUTCOME MEASURES: The percentage change in death rates per 100,000 population was used to examine the trend. Epi Info was used to map the geographic distribution of road-traffic death rates and the increases in rates. Correlation coefficients were calculated between per capita gross regional product, road quality, and the number of motor vehicles in the 31 provinces, to help understand the geographic variations in road-traffic mortality at the provincial level in China. RESULTS: The road-traffic death rate increased by 95%, from 3.9/100,000 persons in 1985 to 7.6/100,000 persons in 2005. High death rates and the greatest increases in death rates occurred in both developed provinces in the southeast and underdeveloped northern and western provinces. Xizang/Tibet, Qinghai, and Xinjiang, with the lowest population density, had the highest death rates per 100 vehicles. CONCLUSIONS: China's government should introduce and support measures to prevent road-traffic injuries. Developed and underdeveloped provinces in China should both be considered when road-traffic policy and interventions are developed.

Reducing black/white disparity: changes in injury mortality in the 15-24 year age group, United States, 1999-2005.

In 1999, the injury death rate for black males aged 15-24 in the USA was 80% greater than for white males: 148.5 vs 82.5/100,000, a difference of 66/100,000. Injury-specific changes between 1999 and 2005 in death rates for the 15-24 age group and in racial disparity were analysed using data from CDC's WISQARS. The gap between black and white all-injury death rates in males was reduced by 24%, to a difference of 50/100,000, largely because of greater decreases in the rates for motor vehicle crashes and firearm suicide in young black men than young white men, and large increases in suicide by suffocation and unintentional poisoning in the latter. Among females, despite a reduction in the black/white gap in firearm homicide rates, the gap between the races in total injury rates changed from a small black excess to a higher rate in young white women, which was due primarily to greater increases in these white women than black women in unintentional poisoning and suicide by suffocation, and greater decreases in black women than white women in firearm suicide.

MDCT of 220 consecutive patients with suspected acute pulmonary embolism: incidence of pulmonary embolism and of other acute or non-acute thoracic findings.

PURPOSE: This study was undertaken to evaluate the incidence of pulmonary embolism (PE) and other clinically relevant thoracic findings discovered on contrast-enhanced multidetector computed tomography (MDCT) examination in patients with a suspicion of acute PE. MATERIALS AND METHODS: We retrospectively reviewed 220 reports of 40-row MDCT exams in consecutive patients (101 men, 119 women; mean age 55 years+/-18) suspected for acute PE. Presenting symptoms and risk factors were recorded. Image quality and incidence of PE and other clinically relevant thoracic findings were evaluated. RESULTS: MDCT were diagnostic in 96.8% of patients. Nineteen patients (8.6%) were positive for PE. Signs and symptoms were present in 82.7% (182) and risk factors in 38.2% (84) of the population. Clinically relevant thoracic findings were detected in 45.9% (101) of the patients. Ten patients had PE and other thoracic findings. Half of the patients (110) had neither PE nor other clinically relevant thoracic findings. CONCLUSIONS: Chest MDCT, with an excellent overall image quality, provided an explanation for the clinical presentation in about 50% of emergency department patients studied and was useful in detecting PE and other thoracic diseases with symptoms mimicking PE. However, half of the exams were negative.

Injury control: an opportunity for China.

Injury control is an important health issue in China, but has been less well explored than in other countries. To encourage health policy makers to give greater attention to injury control, this report highlights the great damage caused by injuries and the neglected status of injury control in China. China's situation and the experiences and lessons from industrialized countries, especially the USA, are summarized. Finally, two opportunities to improve injury control in China are identified: establishment of a mechanism for multi-department coordination and collaboration; and improvement of injury data surveillance.

The SAGA continues: expanding the cellular role of a transcriptional co-activator complex.

Throughout the last decade, great advances have been made in our understanding of how DNA-templated cellular processes occur in the native chromatin environment. Proteins that regulate transcription, replication, DNA repair, mitosis and other processes must be targeted to specific regions of the genome and granted access to DNA, which is normally tightly packaged in the higher-order chromatin structure of eukaryotic nuclei. Massive multiprotein complexes have been discovered, which facilitate access to DNA and recruitment of downstream effectors through three distinct mechanisms: chemical modification of histone amino-acid residues, ATP-dependent chromatin remodeling and histone exchange. The yeast Spt-Ada-Gcn5-Acetyl transferase (SAGA) transcriptional co-activator complex regulates numerous cellular processes through coordination of multiple histone post-translational modifications. SAGA is known to generate and interact with a number of histone modifications, including acetylation, methylation, ubiquitylation and phosphorylation. Although best characterized for its role in regulating transcriptional activation, SAGA is also required for optimal transcription elongation, mRNA export and perhaps nucleotide excision repair. Here, we discuss findings from recent years that have elucidated the function of this 1.8-MDa complex in multiple cellular processes, and how misregulation of the homologous complexes in humans may ultimately play a role in development of disease.

Inmate-made weapons in prison facilities: assessing the injury risk.

More than 2400 correctional workers in the United States required medical attention in 1999 following assaults by inmates, often with unconventional "homemade" weapons. Little information is available about these weapons. The authors surveyed 101 state prisons for a 12 month period within 2002-03, and 70 responded. A total of 1326 weapons were either confiscated (1086) or used to injure inmates (203) or staff (37). Staff were most often attacked with clubs. The prison store was the most common source of materials used to make confiscated weapons. Issued items were the most common source of materials used to make weapons to injure staff. The injury rate for staff was 1.0/1000 workers per year. The annual cost of injuries for time lost and medical care for staff was estimated at $1,125,000 in these 70 prisons. Results identify materials that should be redesigned to prevent modifications to make weapons. Prison stores and issued items deserve special attention.

Interventions to prevent softball related injuries: a review of the literature.

OBJECTIVES: To examine the published evidence on interventions to prevent softball related injuries among adults, and to encourage more epidemiologic research as a foundation for future softball injury prevention efforts. METHODS: The authors reviewed literature identified from six electronic databases for studies on softball related injuries. The search was limited to studies written in the English language, published between 1970 and 2002, and involving adult populations. Research was excluded that evaluated baseball ("hard ball") related injuries or was aimed at injury treatment. Identified studies were categorized by study design. Intervention/prevention papers were evaluated further and described in detail. RESULTS: The search strategy identified 39 studies specifically related to softball. Most studies were case reports/case series (n=13) or descriptive studies (n=11); only four were analytic or intervention/prevention studies. Studies collected data in a variety of ways, often without denominator data to permit calculation of injury rates. Studies also did not differentiate between slow or fast pitch softball activities and most did not mention the type of softball that was used. CONCLUSIONS: Surprisingly few studies exist on interventions to reduce injuries during softball, one of the most popular recreational sports in the US. Of the existing literature, much attention has been on sliding related injuries, which comprise only a segment of softball injuries. Basic epidemiologic studies describing the nature, severity, and risk factors for softball injuries in a variety of populations are needed, followed by additional intervention evaluation studies aimed at modifiable risk factors.

Long-term changes in glutamatergic synaptic transmission in phenylketonuria.

The cellular mechanisms that underlie impaired brain function during phenylketonuria (PKU), the most common biochemical cause of mental retardation in humans, remain unclear. Acute application of L-Phe at concentrations observed in the PKU brain depresses glutamatergic synaptic transmission but does not affect GABA receptor activity in cultured neurons. If these depressant effects of L-Phe take place in the PKU brain, then chronic impairment of the glutamate system, which may contribute to impaired brain function, could be detected as changes in postsynaptic glutamate receptors. This hypothesis was tested by using a combination of liquid chromatography-mass spectrometry, patch-clamp, radioligand binding and western blot approaches in forebrain tissue from heterozygous and homozygous (PKU) Pah(enu2) mice. Brain concentrations of L-Phe were nearly six-fold greater in PKU mice (863.12 +/- 17.96 micromol/kg) than in their heterozygous counterparts (149.32 +/- 10.23 micromol/kg). This concentration is significantly higher than the K(B) of 573 microM for L-Phe to compete for N-methyl-D-aspartate (NMDA) receptors. Receptor binding experiments with [3H]MK-801 showed significant up-regulation of NMDA receptor density in PKU mice. Consistent with the depressant effects of L-Phe, expression of NMDA receptor NR2A and (RS)-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor Glu1 and Glu2/3 subunits was significantly increased, whereas expression of the NR2B subunit was decreased. There was no change in GABA alpha1 subunit expression. Given the role of the glutamatergic system in brain development and function, these changes may, at least in part, explain the brain disorders associated with PKU.

Independent predictors of morbidity and mortality in blunt colon trauma.

We sought to determine the impact of (1) grade of the colon injury, (2) the formation of an ostomy, and (3) associated injuries on outcomes such as morbidity and mortality after blunt colon injuries. We retrospectively reviewed 16,814 cases of blunt abdominal trauma. Patients with colonic injuries were selected and charts reviewed for demographic, clinical, and outcomes data. Injuries were grouped by the Colon Injury Scale (grades I-V). Independent risk factors of morbidity included spine and lung injuries, as well as increased age. A higher grade of colon injury trended toward a significant association with intra-abdominal complications. Independent risk factors of mortality included liver, heart, and lung injuries, as well as intracerebral blood and female gender. The grade of colon injury, the formation of an ostomy, and management of the colon trauma did not independently predict increased intra-abdominal complications, morbidity, or mortality. These results indicate that patients afflicted with blunt colon trauma experience a high rate of morbidity and mortality from associated injuries and or increased age. Treatment regimens directed at these factors will be most helpful in reducing the high morbidity and mortality after blunt colon trauma. Factors such as ostomy formation and management strategy are not associated with increased morbidity or mortality after blunt colon trauma.

Using multiple information sources to identify opportunities for ergonomic interventions in automotive parts distribution: a case study.

An essential activity in any ergonomics program is determining specific work locations and activities where physical demands place workers at increased risk of sustaining an overexertion injury. To do this, safety and health professionals rely on a variety of information sources to identify and prioritize opportunities for ergonomic interventions. As part of a 4-year project to reduce overexertion injuries in the service parts division of a major auto maker, a study was performed in 19 parts distribution centers to evaluate the contributions of the following information sources in identifying specific high-risk work locations and activities: (1) archival medical/injury records, (2) identification of "problem tasks" by plant-based ergonomic committees, (3) facility walk-throughs by experienced ergonomists, and (4) detailed ergonomic job analyses. Archival records were not particularly useful in identifying high-risk activities because essential exposure information (e.g., task, work location) was not documented. Walk-throughs and detailed ergonomic analyses were partially effective in identifying high-risk activities; however, in some cases the observation time was too short to observe peak exposures. Ergonomic committees were generally effective in identifying specific high-risk tasks and work locations. Rankings of "problem tasks" from multiple sites identified consensus division-wide ergonomic concerns. Detailed ergonomic job analyses confirmed that these tasks had high exposure to ergonomic risk factors. This study demonstrated potential pitfalls in relying on a single information source to identify work locations and activities that place workers at increased risk of overexertion injury.

Changes in injury patterns in frontal crashes: preliminary comparisons of drivers of vehicles model years 1993-1997 to drivers of vehicles 1998-2001.

Injury severity among drivers of vehicles model year 1993-1997 was compared to that of drivers of vehicles 1998-2001. Data from the National Automotive Sampling System Crashworthiness Data Sets 1993-2000 were used. Differences in injury patterns by model year and gender, type of vehicle, single- or multiple-car crash, severity of crash, safety belt use and airbag deployment were investigated. The 1206 eligible drivers in newer vehicles presented significantly fewer and less severe injuries than their 3827 pre-1998 model year counterparts. This is true for men and women, across severity of crash, and even when confounders are accounted for. The re-design of frontal airbags that occurred around 1998 could be partly responsible for these improvements.

Drinking histories of fatally injured drivers.

CONTEXT: About 30% of drivers killed in crashes have high blood alcohol concentrations (BACs) of 0.10+ g/dl. There is a question about whether these drivers primarily are problem drinkers who chronically drink and drive-the so-called hard core drinking drivers. OBJECTIVE: To investigate drinking histories of fatally injured drivers in relation to their BACs. DESIGN AND PARTICIPANTS: Retrospective cohort study of 818 fatally injured drivers who were included in the 1993 National Mortality Followback Survey (a national sample of US deaths in which next of kin were interviewed) and whose BACs were recorded by the Fatality Analysis Reporting System, a census of US traffic deaths. MAIN OUTCOME MEASURE: Problem drinking indicators. RESULTS: At least one indicator of potential problem drinking, primarily heavy drinking, was reported for 68% of drivers with very high BACs (0.15+ g/dl), 41% with BACs of 0.10-0.14 g/dl, 32% with BACs of 0.01-0.09 g/dl, and 7% with zero BACs. Spouses provided more credible responses than other relatives: they were more likely to report at least occasional drinking and driving among deceased drivers with high BACs. For the most direct signs of problem drinking (described as a problem drinker during the last month of life or frequently driving after having five or more drinks), spousal reports suggested the prevalence of problem drinking among drivers with very high BACs was 22% (having both indicators), 32% (frequently driving after having five or more drinks), 44% (described as problem drinker), or 57% (having either indicator). CONCLUSIONS: Drivers with BACs of 0.10+ g/dl were far more likely than sober drivers to be described as having markers of problem drinking. However, many did not have indicators suggestive of problem drinking. In addition to programs focused on repeat offenders or problem drinkers, countermeasures such as sobriety checkpoints that target a broader spectrum of drinking drivers are appropriate.

General aviation crashes involving military personnel as pilots.

BACKGROUND: Injuries sustained in off-duty activities are a major cause of mortality and morbidity among military personnel. Reducing these off-duty fatalities is a continuing priority of the military. METHODS: General aviation crashes recorded by the National Transportation Safety Board between 1983 and 1998 were analyzed for military pilots (n = 205) and other military personnel (n = 185), and compared with all other general aviation crashes (n = 32,807) to identify differences in the crash circumstances and sustained injury severities. RESULTS: During the 16-yr study period, a total of 45 military pilots and 52 other military personnel were fatally injured while flying general aviation flights. Military pilots who were involved in general aviation crashes were more likely to have advanced licenses and higher total flight times when compared with other military personnel and civilian pilots (p < 0.05). Among the three groups of pilots, other military personnel had the least flying time and the largest percentage of student/private licenses. Military personnel had significantly less time in type in the 90-d and 30-d periods preceding the crash compared with civilians (p < 0.05). Shoulder restraint usage was associated with less severe injuries for all groups. We estimate that general aviation deaths have cost the military at least $405 million since 1983. CONCLUSIONS: General aviation crashes are a costly source of mortality and morbidity for military personnel, particularly military pilots. Interventions aimed at improving safety of military personnel in the general aviation setting warrant special consideration.

Mersilene mesh sling: short- and long-term clinical and urodynamic outcomes.

OBJECTIVE: We sought to determine the long-term efficacy, safety, and urodynamic effects of the Mersilene mesh suburethral sling in treating complicated forms of genuine stress incontinence. STUDY DESIGN: Two hundred women diagnosed with genuine stress incontinence, complicated by recurrence, intrinsic sphincter deficiency, or chronically increased intraabdominal pressure underwent a suburethral mesh sling procedure (Mersilene; Ethicon Inc, Somerville, NJ). They were monitored with yearly clinical examinations plus short- and long-term postoperative urodynamic evaluations; statistical analysis was carried out by use of the Friedman 2-way analysis by rank, Fischer-Freeman-Halton exact testing, analysis of variance for repeated measures, Wilcoxon, exact Mann-Whitney U test, and Bonferroni paired t test. Of 176 patients who were 5 months or more postop, 127 (72%) had preoperative and short-term postoperative urodynamic evaluations (range 5 to 23 months, mean 12.6 months). Fifty-two of 117 women who were more than 19 months postop (44%) completed preoperative and long-term postoperative urodynamic evaluations at a mean of 63 months (range 20 to 107). One hundred thirty-six of 176 patients (77%) who were more than 4 months postop had a short- and/or long- term postoperative urodynamic evaluation (range 5 to 107 months, mean 30 months). RESULTS: Objective cure rate by stress test was 93% (126 of 136 patients) at a mean of 30 months follow-up. The long-term objective cure rate was 94% (49 of 52). Subjectively, the short- and long-term cure rates were 95.3% and 90.4%, respectively. The cotton swab angle deflection decreased by a mean of 54 degrees at 1 year and 50 degrees at 5 years. Of the 10 failures, the mean preoperative cotton swab straining angle was 19.6 degrees, with 6 being < 30 degrees. Nineteen patients had a negative preoperative cotton swab angle test result (mean straining angle 15 degrees before operation, -6 degrees after operation) and a long-term cure rate of 67%. The objective cure rate in patients with positive cotton swab angle results monitored long term (mean 62 months) was 100% (41 of 41). The postvoid residual increased by a mean of 25 mL short term and 10 mL long term. Thirty-eight patients (19%) had a total of 43 complications. Seven patients (3.5%) had long-term retention. De novo detrusor instability occurred in 12 patients (8.8%), although it was cured in 6 (4.4%). Eight patients (4%) had vaginal or inguinal sling erosion and were healed after revision. Delayed healing at the vaginal sling site responded completely to estrogen cream in two (1%) patients. Five women had treatable vaginal stenosis, 5 had a local inguinal collection/infection unrelated to the mesh, and 3 required a 2-unit transfusion of packed red blood cells. One patient each had an entrapped nerve released, a cystotomy repaired, or experienced thigh numbness or groin pain. CONCLUSIONS: The suburethral Mersilene mesh sling has a very high long-term objective and subjective cure rate in the treatment of complicated forms of genuine stress incontinence. Frequent complications do occur but are remediable. The 33% failure rate among patients with a preoperative negative cotton swab angle test result and the very low cotton swab straining angle among the 7% who had sling failures further confirms the widely held belief that sling urethropexy in the absence of hypermobility lacks efficacy.

Potential benefits of restrictions on the transport of teenage passengers by 16 and 17 year old drivers.

OBJECTIVES: The presence of passengers is associated with fatal motor vehicle crashes of teenage drivers. A restriction against newly licensed teenage drivers carrying passengers has been included in some, but not all, graduated licensing systems. The purpose of this study was to predict the net effects on all types of road users, including vehicle occupants and non-occupants, of possible prohibitions against 16-17 year old drivers carrying passengers. METHODS: Two national datasets, a census of fatal crashes and a sample of trips in the United States, were used to compute 1995 road user death rates. Potential effects of restrictions on drivers ages 16-17 carrying passengers younger than 20 were estimated, based on road user death rates and potential choices made by passengers who would have traveled with 16-17 year old drivers if there were no restrictions. RESULTS: There were 1,181 road user deaths in 1995 involving drivers ages 16-17 whose passengers were all younger than age 20. The predicted number of lives in the United States that would be saved annually ranges from 83 to 493 (corresponding to reductions of 7-42% in road user deaths) for drivers ages 16 and 17 combined. Similar percentages of reductions (8-44%) were predicted solely for 16 year old drivers. Assuming passenger restrictions would apply to all 16 year old drivers and at least one third of 17 year old drivers, an estimated 60-344 fewer deaths per year may occur if restrictions are mandated. CONCLUSIONS: Restrictions on carrying passengers younger than 20 should be considered for inclusion in graduated licensing systems. Even if fewer than half the drivers obey the restrictions, a substantial reduction in road user deaths would be expected. Further evaluation based on real world experience is needed to confirm their efficacy.

Novel short-acting A2A adenosine receptor agonists for coronary vasodilation: inverse relationship between affinity and duration of action of A2A agonists.

Several potent and selective A2A adenosine receptor agonists are currently available. These compounds have a high affinity for the A2A receptor and a long duration of action. However, in situations where a short duration of action is desired, currently available A2A receptor agonists are less than ideal. From a series of recently synthesized A2A receptor agonists, two agonists (CVT-3146 and CVT-3033) with low affinity were selected for further characterization as selective and short-acting coronary vasodilators. Both compounds were selective for the A2A adenosine receptor (AdoR) versus the A1, A2B, and A3AdoR in binding and functional studies. CVT-3146 and CVT-3033 appeared to be weak partial agonists to cause cAMP accumulation in PC12 cells, but were full and potent agonists to cause coronary vasodilation, a response that has a very large A2A receptor reserve. However, the durations of action of CVT-3146 and CVT-3033 were remarkably shorter than those of the high-affinity agonists CGS21680 or WRC0470, presumably due to the relative lower affinity of CVT-3146 and CVT-3033 for the A2A receptor. Indeed, an inverse relationship was found between the affinity of the various agonists for the A2A receptor and the duration of their actions. These data indicate that low-affinity agonists can produce a response that is of equivalent magnitude but more rapid in termination than that caused by a high-affinity agonist. Hence, the low-affinity A2A agonists CVT-3146 and CVT-3033 may prove to be superior to currently available high-affinity agonists as coronary vasodilators during myocardial imaging with radionuclide agents.

Characteristics of general aviation crashes involving mature male and female pilots.

BACKGROUND: General aviation crashes in the United States were analyzed to identify differences between male and female pilots in the circumstances of their crashes and the types of pilot errors involved. METHODS: All 144 female pilots who were born between 1933 and 1942 and who were involved in general aviation crashes between 1983 and 1997 were matched 1:2 with 287 male pilots by age within 2 yr, medical certificate and pilot certificate, state or region of crash, and year of crash. RESULTS: Mechanical failure, gear up landings, improper IFR approaches, and collisions with wires or poles were more common in crashes of male pilots. Loss of control on landing/takeoff was more common in crashes of female pilots. Mishandling aircraft kinetics was the most common error of pilots of both genders and was noted more often in female pilots' crashes (81% vs. 48%) (p < 0.001). Males' crashes were more likely to involve flawed decisions (29% vs. 19% of females' crashes) (p = 0.027) or inattention (32% vs. 19%) (p = 0.004). Older pilots made fewer errors: among males age 55-63, 26% of crashes were without obvious pilot error compared with only 7% at age 40-49 (p = 0.003). CONCLUSION: There are large gender differences in the types of pilot error involved in general aviation crashes. Mishandling aircraft kinetics, poor decision making, and inattention are the most common pilot errors and merit increased attention in pilot training.

Use of alcohol as a risk factor for bicycling injury.

CONTEXT: Bicycling is one of the leading causes of recreational injuries. Elevated blood alcohol concentrations (BACs) are found in about one third of fatally injured bicyclists aged 15 years or older. OBJECTIVE: To assess the relative risk of fatal and serious bicycling injury according to BAC. DESIGN: Matched case-control study. SETTING AND SUBJECTS: Bicyclists aged 15 years or older who were fatally or seriously injured while riding a bicycle during the day in Maryland in 1985-1997 (cases, n = 124) and bicyclists aged 15 years or older who were interviewed and given a breath test for estimated BAC during roadside surveys that took place in June 1996 through May 1998 at the same site, time of day, day of week, and month of year in which a case bicyclist was injured (controls, n = 342). MAIN OUTCOME MEASURE: Odds ratio of bicycling injury according to estimated BAC. RESULTS: An estimated positive BAC (>/=0.02 g/dL) was detected in 12.9% of the case bicyclists (23.5% of the 34 fatally injured and 8.9% of the 90 seriously injured) compared with 2.9% of the control bicyclists (P<.001). Relative to an estimated BAC of less than 0.02 g/dL, the adjusted odds ratio of bicycling injury was 5.6 (95% confidence interval [CI], 2.2-14.0) for a BAC of 0.02 g/dL or higher and was 20.2 (95% CI, 4.2-96.3) for a BAC of 0.08 g/dL or higher. Rates of helmet use at the time of injury or interview were 5% and 35%, respectively, for those with and without a positive BAC (P =.007). CONCLUSION: Alcohol use while bicycle riding is associated with a substantially increased risk of fatal or serious injury.

Evaluation of linear and nonlinear tomosynthetic reconstruction methods in digital mammography.

RATIONALE AND OBJECTIVES: The purpose of this study was to comparatively evaluate digital planar mammography and both linear and nonlinear tomosynthetic reconstruction methods. MATERIALS AND METHODS: A "disk" (ie, target) identification study was conducted to compare planar and reconstruction methods. Projective data using a composite phantom with circular disks were acquired in both planar and tomographic modes by using a full-field, digital mammographic system. Two-dimensional projections were reconstructed with both linear (ie, backprojection) and nonlinear (ie, maximization and minimization) tuned-aperture computed tomographic (TACT) methods to produce three-dimensional data sets. Four board-certified radiologists and one 4th-year radiology resident participated as observers. All images were compared by these observers in terms of the number of disks identified. RESULTS: Significant differences (P < .05, Bonferroni adjusted) were observed between all reconstruction and planar methods. No significant difference, however, was observed between the planar methods, and only a marginally significant difference (P < .054, Bonferroni adjusted) was observed between TACT-backprojection and TACT-minimization. CONCLUSION: A combination of linear and nonlinear reconstruction schemes may have potential implications in terms of enhancing image visualization to provide radiologists with valuable diagnostic information.

Secular trends of motor vehicle mortality in the United States, 1910-1994.

To examine the secular trends of mortality from motor vehicle crashes, the authors compiled annual population and mortality data for the United States from 1910 to 1994 and performed an age-period-cohort analysis through graphical presentation, median polish, and Poisson regression modeling. During the 85-year study period, death rates from motor vehicle crashes showed two peaks, first in 1935-39 and then in 1965-69. Age and period effects accounted for 94% of the variation in motor vehicle mortality in men and 84% of the variation in women. Age patterns of motor vehicle mortality varied greatly with birth cohorts: for those who were born before 1910, death rates increased with age; for those born after 1910, death rates peaked at age 20-24 years for men and at age 15-19 years for women. A crossover characterized by a downward trend in death rates among the elderly and an upward trend among adolescents and young adults was observed in both sexes. The complex age, period, and cohort patterns of motor vehicle mortality are likely to have been shaped by changes in traffic patterns and driver behavior, and by improvements in safety design and emergency medical service systems.