Prescribing in the prehospital environment: a review of the pharmaceutical Module 501 on UK Military Exercise SAIF SAREEA 3. Can such analysis assist with the scaling of healthcare assets?

INTRODUCTION

Module 501 provides core medications which are fundamental to the capability of a prehospital treatment team (PHTT). The quantities of each medication in the module inventory undergo regular review, but these do not correspond to a population at risk (PAR) figure or deployment length for which they intend to be used. This article proposes how the quantities of Module 501 drugs can be scaled for a given deployment, in this example using statistics taken from static PHTTs on Exercise Saif Sareea 3 (SS3).

METHODS

The statistics were gathered using a custom-built search of electronic records from the Deployed Defence Medical Information Capability Programme in addition to written record-keeping, which were aligned to the weekly PAR at each PHTT location throughout their full operational capability periods. A quotient was then derived for each module item using a formula.

RESULTS

Among the 10 most commonly prescribed drugs were four analgesics and three antimicrobials. 42 of the 110 studied drugs were not prescribed during SS3.

DISCUSSION

The data from SS3 reflect the typical scope of disease encountered in the deployed land setting. Employing these data, the use of a formula to estimate the drug quantities needed to sustain a Strike Armoured Infantry Brigade over a 28-day period is demonstrated.

RECOMMENDATIONS

Further study of Module 501 across varied deployment environments would be valuable in evolving this approach to medicinal scaling if proven effective for the warm desert climate. It could then be applied to other modules to further inform future Strike medical planning.

LIMITATIONS

Several considerations when drawing deductions from the data are mentioned, including the inaccuracy of predictor variables taken from the EpiNATO-2 reports.

CONCLUSION

The proposed formula provides an evidence-based framework for scaling drug quantities for a deployment planning. This may improve patient safety and confer logistical, storage and fiscal benefits.

Encephalitis on deployment in Kenya: think beyond the infections

A 34-year-old female soldier presented with fever and behavioural changes while deployed in Kenya and was diagnosed with encephalitis. The patient underwent urgent aeromedical evacuation to the Queen Elizabeth Hospital, Birmingham for further management. Microbiology tests excluded common infectious causes that are endemic in the East Africa region. However, an autoantibody screen was positive for antibodies against the N-methyl-D-aspartate receptor (NMDAR). Full body imaging confirmed the presence of limbic encephalitis and an ovarian mass suggestive of a teratoma. The patient was diagnosed with ovarian teratoma-associated anti-NMDAR encephalitis, a potentially fatal disease. The patient underwent surgery to remove the teratoma and commenced immunotherapy with steroids, plasma exchange and rituximab. This case highlights the diagnostic challenges of fever with behavioural changes in military personnel deployed in a tropical environment.

Acetaldehyde and retinaldehyde-metabolizing enzymes in colon and pancreatic cancers

Colorectal cancer (CRC) and pancreatic cancer are two very significant contributors to cancer-related deaths. Chronic alcohol consumption is an important risk factor for these cancers. Ethanol is oxidized primarily by alcohol dehydrogenases to acetaldehyde, an agent capable of initiating tumors by forming adducts with proteins and DNA. Acetaldehyde is metabolized by ALDH2, ALDH1B1, and ALDH1A1 to acetate. Retinoic acid (RA) is required for cellular differentiation and is known to arrest tumor development. RA is synthesized from retinaldehyde by the retinaldehyde dehydrogenases, specifically ALDH1A1, ALDH1A2, ALDH1A3, and ALDH8A1. By eliminating acetaldehyde and generating RA, ALDHs can play a crucial regulatory role in the initiation and progression of cancers. ALDH1 catalytic activity has been used as a biomarker to identify and isolate normal and cancer stem cells; its presence in a tumor is associated with poor prognosis in colon and pancreatic cancer. In summary, these ALDHs are not only biomarkers for CRC and pancreatic cancer but also play important mechanistic role in cancer initiation, progression, and eventual prognosis.

Influence of nutrient levels in Tamarix on Diorhabda sublineata (Coleoptera: Chrysomelidae) survival and fitness with implications for biological control

Establishment of the saltcedar leaf beetle (Diorhabda spp.) has been unpredictable when caged or released in the field for saltcedar (Tamarix spp.) biocontrol. It has been observed that one caged tree might be voraciously fed upon by beetles while an adjacent tree in the cage is left untouched. We hypothesized that differences in the nutrient content of individual trees may explain this behavior. We evaluated survival, development rate, and egg production of beetles fed in the laboratory on saltcedar foliage from trees that had been grown under a range of fertilizer treatments. Tissue samples from the experimental trees and from the field were analyzed for percent nitrogen, phosphorus, and potassium. There was essentially no survival of beetle larvae fed foliage from saltcedar trees at nitrogen levels below 2.0%. At levels above 2.0% N, beetle larvae had corresponding increased survival rates and shorter development times. Multiple regression analyses indicated that nitrogen and phosphorus are important for larval survival and faster development rates. Higher levels of potassium were important for increased egg cluster production. The plant tissue analysis showed that the percentage of nitrogen in the experimental trees reflected the range of trees in the field and also that there is high variability within trees in the field. Our research indicates that if beetles are released on trees with poor nutrient quality, the larvae will not survive.

Postharvest Decay Management for Stone Fruit Crops in California Using the "Reduced-Risk" Fungicides Fludioxonil and Fenhexamid

In laboratory studies and experimental packingline trials that closely simulated fungicide treatments under commercial conditions, the "reduced-risk" fungicides fenhexamid and fludioxonil were highly effective in managing postharvest brown rot and gray mold decays of peach, nectarine, and plum caused by Monilinia fructicola and Botrytis cinerea, respectively. Tebuconazole was more effective against brown rot than against gray mold. Additionally, fludioxonil and tebuconazole significantly reduced the incidence of Rhizopus rot caused by Rhizopus stolonifer. In laboratory studies, the QoI fungicide azoxystrobin was not consistent in its decay control activity. The high efficacy of fenhexamid and fludioxonil against brown rot and gray mold was substantiated by low effective concentrations necessary (≤0.063 mg/liter)for 50% inhibition of mycelial growth in vitro. In general, fungicides applied 14 to 16 h after wound inoculation were significantly more effective than those applied before inoculation. These results indicate that the fungicides act mainly as protectants that do not penetrate deeply enough into the fruit to prevent decay from wounds that extend below the fruit epidermis. Laboratory treatments of plum fruit generally were less effective than those of peach or nectarine fruit. Comparative studies using either low-volume spray or high-volume, in-line drench applications over a roller bed demonstrated that drench applications were significantly more effective in reducing postharvest decaysof inoculated plum fruit. Decay incidence using fenhexamid or fludioxonil was ≤1.1%, whereas incidence after the spray applications was between 25.2 and 40.4% for brown rot, between 12.0 and 24.3% for gray mold, or 62.6% for Rhizopus rot (fludioxonil only). This research identified effective replacements for iprodione, a fungicide voluntarily canceled by the manufacturer in 1996.

Establishing guidelines to improve identification of fire ants Solenopsis xyloni and Solenopsis invicta

As red imported fire ant, Solenopsis invicta Buren, continues to expand its range into the southwestern United States, it can be easily confused with the native southern fire ant, Solenopsis xyloni McCook. Variability in the morphological characteristics commonly used to differentiate these ant species was quantified by examining the length of the clypeal tooth, striations of the mesopleuron, length of antennal scape, area of the petiolar process, number and size of mandibular teeth, and color by using both scanning electron and light microscopy. Given enough samples, the average values of each of these characteristics is different between the two species; however, significant morphological variability occurs in both S. xyloni and S. invicta populations, creating an area of overlap where either of the two species could exhibit similar characteristics. Better differentiation of these two species is achieved using a combination of characteristics, but morphological techniques are not dependable unless numerous ants from each population are analyzed by a taxonomist familiar with Solenopsis. For situations requiring a more accurate identification, such as before quarantining a county or a portion of a county, a molecular technique using mitochondrial DNA and polymerase chain reaction techniques was developed.

Duloxetine (Cymbalta™), a dual inhibitor of serotonin and norepinephrine reuptake

A series of naphthalenyloxy-arylpropylamines have been prepared and are demonstrated to be inhibitors of both serotonin and norepinephrine reuptake. One member of this series, duloxetine (Cymbalta) has proven to be effective in clinical trials for the treatment of depression.

Research on injury prevention: topics for systematic review

BACKGROUND

Duplication should be avoided in research and only effective intervention programs should be implemented.

OBJECTIVE

To arrive at a consensus among injury control investigators and practitioners on the most important research questions for systematic review in the area of injury prevention.

DESIGN

Delphi survey.

METHODS

A total of 34 injury prevention experts were asked to submit questions for systematic review. These were then collated; experts then ranked these on importance and availability of research.

RESULTS

Twenty one experts generated 79 questions. The prevention areas with the most number of questions generated were fires and burns, motor vehicle, and violence (other than intimate partner), and the least were other interventions (which included Safe Communities), and risk compensation. These were ranked by mean score. There was good agreement between the mean score and the proportion of experts rating questions as important or very important. Nine of the top 24 questions were rated as having some to a substantial amount of research available, and 15 as having little research available.

CONCLUSIONS

The Delphi technique provided a useful means to develop consensus on injury prevention research needs and questions for systematic review.

Comparative metabolism, covalent binding and toxicity of BHT congeners in rat liver slices

The metabolism, covalent binding and hepatotoxicity of butylated hydroxytoluene (BHT, 4-methyl-2,6-di-t-butylphenol) and two congeners (E-BHT, 4-ethyl-2,6-di-t-butylphenol; I-BHT, 4-isopropyl-2,6-di-t-butylphenol) were compared using precision-cut liver slices prepared from phenobarbital (PB)-treated male Sprague-Dawley rats. At equimolar concentrations (1 mM) BHT was the most toxic of the three compounds, causing an 80% decrease in cell viability over a 6 h incubation period. E-BHT was intermediate in toxicity while the isopropyl derivative was relatively nontoxic. Intracellular glutathione levels decreased prior to the onset of cytotoxicity. The cytochrome P450 inhibitor metyrapone completely inhibited the toxicity of all three compounds. The rates of metabolism of the three compounds to glutathione conjugates were compared in both PB-treated microsomes and PB-induced liver slices. In both models, the rate of formation was greatest for BHT, followed by E-BHT and I-BHT. Synthetic quinone methides (QMs) were prepared from each parent phenol and the rates of reactivity with three nucleophiles (water, methanol and glutathione) were compared. With each nucleophile, BHTQM was the most reactive, while I-BHTQM was the least reactive. Finally, covalent binding to protein was assessed in two ways. First, alkylation of an isolated model protein (bovine insulin) was measured in a microsomal enzyme activation system by mass spectrometry. Incubations with BHT produced the greatest extent of protein alkylation, followed by E-BHT, while no alkylation was observed with I-BHT. In the second system, covalent binding to cellular protein was assessed in rat liver PB microsomes and tissue slices by Western blotting using an antibody specific for the tert-butylphenol portion of the compounds. Binding was greatest for BHT, intermediate for E-BHT and could not be detected for I-BHT. The alkylation pattern for E-BHT was strikingly similar to that of BHT, suggesting that both compounds bound similar proteins. In summary, our results suggest that for hindered phenols such as BHT, increasing the length of the 4-alkyl substituent retards the rate of formation of reactive intermediates, significantly reduces the electrophilicity of the reactive intermediate, and greatly reduces the amount but not the selectivity of covalent binding to cellular protein, thereby reducing the toxicity of the parent compound.

Universal newborn hearing screening: summary of evidence

CONTEXT

Each year, approximately 5000 infants are born in the United States with moderate-to-profound, bilateral permanent hearing loss (PHL). Universal newborn hearing screening (UNHS) has been proposed as a means to speed diagnosis and treatment and thereby improve language outcomes in these children.

OBJECTIVES

To identify strengths, weaknesses, and gaps in the evidence supporting UNHS and to compare the additional benefits and harms of UNHS with those of selective screening of high-risk newborns.

DATA SOURCES

We searched the MEDLINE, CINAHL, and PsychINFO databases for relevant articles published from 1994 to August 2001, using terms for hearing disorders, infants or newborns, screening, and relevant treatments. We contacted experts and reviewed reference lists to identify additional articles, including those published before 1994.

STUDY SELECTION

We included controlled and observational studies of (1) the accuracy, yield, and harms of screening using otoacoustic emissions (OAEs), auditory brainstem response (ABR), or both in the general newborn population and (2) the effects of screening or early identification and treatment on language outcomes. Of an original 340 articles identified, 19 articles, including 1 controlled trial, met these inclusion criteria.

DATA EXTRACTION

Data on population, test performance, outcomes, and methodological quality were extracted by 2 authors (D.C.T., H.M.) using prespecified criteria developed by the US Preventive Services Task Force. We queried authors when information needed to assess study quality was missing.

DATA SYNTHESIS

Good-quality studies show that from 2041 to 2794 low-risk and 86 to 208 high-risk newborns were screened to find 1 case of moderate-to-profound PHL. The best estimate of positive predictive value was 6.7%. Six percent to 15% of infants who are missed by the screening tests are subsequently diagnosed with bilateral PHL. In a trial of UNHS vs clinical screening at age 8 months, UNHS increased the proportion of infants with moderate-to-severe hearing loss diagnosed by age 10 months (57% vs 14%) but did not reduce the rate of diagnosis after age 18 months. No good-quality controlled study has compared UNHS with selective screening of high-risk newborns. In fair- to poor-quality cohort studies, intervention before age 6 months was associated with improved language and communication skills by ages 2 to 5 years. These studies had unclear criteria for selecting subjects, and none compared an inception cohort of low-risk newborns identified by screening with those identified in usual care, making it impossible to exclude selection bias as an explanation for the results. In a mathematical model based on the literature review, we estimated that extending screening to low-risk infants would detect 1 additional case before age 10 months for every 1441 low-risk infants screened, and result in treatment before 10 months of 1 additional case for every 2401 low-risk infants screened. With UNHS, 254 newborns would be referred for audiological evaluation because of false-positive second-stage screening test results vs 48 for selective screening.

CONCLUSIONS

Modern screening tests for hearing impairment can improve identification of newborns with PHL, but the efficacy of UNHS to improve long-term language outcomes remains uncertain.

Identification and management of domestic violence: a randomized trial

BACKGROUND

Diagnosis of domestic violence (DV) in primary care is low compared to its prevalence. Care for patients is deficient. Over a 1-year period, we tested the effectiveness of an intensive intervention to improve asking about DV, case finding, and management in primary care. The intervention included skill training for providers, environmental orchestration (posters in clinical areas, DV questions on health questionnaires), and measurement and feedback.

METHODS

We conducted a group-randomized controlled trial in five primary care clinics of a large health maintenance organization (HMO). Outcomes were assessed at baseline and follow-up by survey, medical record review, and qualitative means.

RESULTS

Improved provider self-efficacy, decreased fear of offense and safety concerns, and increased perceived asking about DV were documented at 9 months, and also at 21 months (except for perceived asking) after intervention initiation. Documented asking about DV was increased by 14.3% with a 3.9-fold relative increase at 9 months in intervention clinics compared to controls. Case finding increased 1.3-fold (95%, confidence interval 0.67-2.7).

CONCLUSIONS

The intervention improved documented asking about DV in practice up to 9 months later. This was mainly because of the routine use of health questionnaires containing DV questions at physical examination visits and the placement of DV posters in clinical areas. A small increase in case finding also resulted. System changes appear to be a cost-effective method to increase DV asking and identification.

Development of a health care provider survey for domestic violence: psychometric properties

BACKGROUND

Despite rapid proliferation of descriptive studies of health care providers (HCPs) and protocols for identification and management of domestic violence (DV), few reliable instruments exist for assessing HCPs' attitudes, beliefs, and behaviors regarding this practice. This study describes the development and psychometric properties of a measure of attitudes, beliefs, and self-reported behaviors related to the identification and management of DV.

METHODS

We used a multiphase study design to develop items across eight content domains. We administered an initial pool of 104 items to a pilot sample of 129 primary care providers (physicians, physician assistants, nurse practitioners, and medical assistants) in a large, urban health maintenance organization. Descriptive statistics, principal components, and reliability analyses were performed on each of the eight content domains. The analyses guided the deletion of items and development of additional items, yielding a 56-item pool. The items were then administered and re-analyzed with an independent sample of 246 HCPs.

RESULTS

Six separate and reliable domains were identified: Perceived Self-Efficacy, System Support, Blame Victim, Professional Role Resistance/Fear of Offending Patient, Victim/Provider Safety, and Frequency of DV Inquiry. We found item domain Cronbach alpha to be acceptable, ranging from 0.73 to 0.91. The final overall measure had 39 items and an alpha of 0.88. Data are reviewed that support the measure's sensitivity to change in response to a training intervention.

CONCLUSION

The measure provides a reliable method for assessing provider characteristics and training needs. It may also serve to evaluate training and policy interventions in DV.

Growth inhibition in G(1) and altered expression of cyclin D1 and p27(kip-1 )after forced connexin expression in lung and liver carcinoma cells

Gap junctional intercellular communication (GJIC) and connexin expression are frequently decreased in neoplasia and may contribute to defective growth control and loss of differentiated functions. GJIC, in E9 mouse lung carcinoma cells and WB-aB1 neoplastic rat liver epithelial cells, was elevated by forced expression of the gap junction proteins, connexin43 (Cx43) and connexin32 (Cx32), respectively. Transfection of Cx43 into E9 cells increased fluorescent dye-coupling in the transfected clones, E9-2 and E9-3, to levels comparable to the nontransformed sibling cell line, E10, from which E9 cells originated. Transduction of Cx32 into WB-aB1 cells also increased dye-coupling in the clone, WB-a/32-10, to a level that was comparable to the nontransformed sibling cell line, WB-F344. The cell cycle distribution was also affected as a result of forced connexin expression. The percentage of cells in G(1)-phase increased and the percentage in S-phase decreased in E9-2 and WB-a/32-10 cells as compared to E9 and WB-aB1 cells. Concomitantly, these cells exhibited changes in G(1)-phase cell cycle regulators. E9-2 and WB-a/32-10 cells expressed significantly less cyclin D1 and more p27(kip-1) protein than E9 and WB-aB1 cells. Other growth-related properties (expression of platelet-derived growth factor receptor-beta, epidermal growth factor receptor, protein kinase C-alpha, protein kinase A regulatory subunit-Ialpha, and production of nitric oxide in response to a cocktail of pro-inflammatory cytokines) were minimally altered or unaffected. Thus, enhancement of connexin expression and GJIC in neoplastic mouse lung and rat liver epithelial cells restored G(1) growth control. This was associated with decreased expression of cyclin D1 and increased expression of p27(kip-1), but not with changes in other growth-related functions.

Systematic reviews of injury-prevention strategies for occupational injuries: an overview

BACKGROUND

Information on which strategies have been shown to be effective, which are ineffective, and which strategies have been inadequately evaluated is important for both public policy and future research.

OBJECTIVE

The objective of this study was to provide systematic reviews of the literature on important strategies to prevent occupational, including agricultural, injuries.

METHODS

The Injury Control Research Centers (ICRCs) funded by the National Center for Injury Prevention and Control (NCIPC), Centers for Disease Control and Prevention, and Centers for Agricultural Injury funded by the Division of Safety Research, the National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention, identified 12 important occupational and agricultural injury-prevention strategies or areas of research. Systematic reviews of the literature were conducted to identify relevant controlled trials and studies. These were critically reviewed and summarized.

RESULTS

A total of 12 reviews were conducted on a range of topics in the occupational injury field. Few randomized controlled trials were found; most controlled studies were either comparisons over time and/or across different populations. In several areas we were limited to summarizing the descriptive literature. Nevertheless, summaries of these studies provide meaningful conclusions about the effectiveness of various interventions to decrease morbidity and mortality from selected occupational and agricultural injuries.

CONCLUSIONS

A large body of literature on occupational, public health, or injury prevention interventions exists. The summary of this literature provides a framework to both direct policy and guide future research efforts.

Prevention of falls in the construction industry: evidence for program effectiveness

OBJECTIVE

The objective of this study was to review the evidence for the effectiveness of different strategies to prevent falls from heights in the construction industry.

SEARCH STRATEGY

We used the Cochrane Collaboration search strategy to search the following electronic databases: MEDLINE, EMBASE, NIOSHTIC, PsycINFO and Dissertation Abstracts. The reference lists from each potentially eligible study were checked, and knowledgeable people in the field were contacted for additional leads to published reports.

SELECTION CRITERIA

Studies were included if they (1) examined the effectiveness of an intervention to decrease falls from heights to construction workers, (2) included data on one of the outcomes of interest, and (3) included a comparison group.

MAIN RESULTS

We identified only three studies for review. An ecologic study found some evidence that regulations with enforcement may decrease falls in construction industry. Two studies on educational efforts suggested that educational programs may decrease falls but methodologic limitations restricted the conclusions that could be drawn.

CONCLUSIONS

There are few data to support the effectiveness of current programs to decrease fall-related injuries in the construction industry. Rigorous evaluation of these interventions is indicated.

Spontaneous hydrolysis of 4-trifluoromethylphenol to a quinone methide and subsequent protein alkylation

4-Trifluoromethylphenol (4-TFMP) was cytotoxic to precision-cut rat liver slices as indicated by loss of intracellular potassium. Intracellular glutathione levels decreased and fluoride ion levels increased in a time and concentration-dependent manner. The cytotoxicity of 4-TFMP did not appear to be due to the release of fluoride, however, since equimolar concentrations of sodium fluoride or potassium fluoride were not toxic. The ortho isomer (2-TFMP), which had a threefold slower rate of fluoride release, was much less toxic to liver slices. In incubations without slices, 4-TFMP spontaneously hydrolyzed in aqueous buffer at physiological pH to form 4-hydroxybenzoic acid via a quinone methide intermediate. The quinone methide was trapped by the addition of glutathione. Analysis of the glutathione adduct indicated that all of the fluorine atoms were lost during the hydrolysis, yielding a cresol derivative with the glutathione moiety attached to a benzylic carbonyl group. The glutathione conjugate was the primary product formed at low alkylphenol/glutathione ratios; however, at higher 4-TFMP concentrations additional unidentified products were observed. 4-TFMP also inhibited the in vitro enzyme activity of purlfied glyceraldehyde-3-phosphate dehydrogenase, a sulfhydryl-dependent enzyme, in a time and concentration-dependentmanner. Loss of thiol residues closely paralleled the loss in enzyme activity. The coaddition of glutathione prevented 4-TFMP-induced loss of enzyme activity. The cytotoxicity of 4-TFMP therefore appears to be due to spontaneous quinone methide formation and subsequent alkylation of cellular macromolecules.

Enhancement in extracellular serotonin levels by 5-hydroxytryptophan loading after administration of WAY 100635 and fluoxetine

It has been demonstrated that synthesis of serotonin (5-HT) is dependent on the availability of precursor, as well as the activity of 5-HT neurons. In the present series of experiments, we examined the effects of precursor (5-HTP) loading on extracellular hypothalamic 5-HT after administration of fluoxetine alone or in combination with WAY 100635, a selective 5-HT1A antagonist. In the first experiment, fluoxetine alone (10 mg/kg i.p.) caused 5-HT levels to significantly increase to 150% of basal levels. Subsequent administration of 5-HTP at 10, 20, and 40 mg/kg i.p. caused 5-HT levels to further increase to a maximum value of 254%, 405%, and 618%, respectively. In the second experiment, either vehicle or WAY 100635 (1 mg/kg/hour s.c.) was infused, then fluoxetine (10 mg/kg i.p.) and 5-HTP (10 mg/kg i.p.) were administered. By itself, WAY 100635 led to a slight but significant increase in hypothalamic 5-HT levels one hour after the start of administration (130% of basal levels). In the WAY 100635-treated group, fluoxetine caused an increase to 240% of basal levels after one hour, which rose to 290% of basal levels after two hours. Subsequent administration of 5-HTP further increased 5-HT levels to 580% of basal levels after one hour. In the vehicle-treated group, fluoxetine caused an increase of 160% of basal levels which was stable over two hours, and subsequent administration of 5-HTP led to a slight increase in 5-HT levels of 220% after one hour. These results suggest that combining blockade of 5-HT1A autoreceptors with 5-HT uptake inhibition results in a synergistic increase in synthesis and release of 5-HT when precursor is administered.

Helmets for preventing head and facial injuries in bicyclists

BACKGROUND

Each year, in the United states, approximately 900 persons die from injuries due to bicycle crashes and over 500,000 persons are treated in emergency departments. Head injury is by far the greatest risk posed to bicyclists, comprising one-third of emergency department visits, two-thirds of hospital admissions, and three-fourths of deaths. Facial injuries to cyclists occur at a rate nearly identical to that of head injuries. Although it makes inherent sense that helmets would be protective against head injury, establishing the real-world effectiveness of helmets is important. A number of case-control studies have been conducted demonstrating the effectiveness of bicycle helmets. Because of the magnitude of the problem and the potential effectiveness of bicycle helmets, the objective of this review is to determine whether bicycle helmets reduce head, brain and facial injury for bicyclists of all ages involved in a bicycle crash or fall.

OBJECTIVES

To determine whether bicycle helmets reduce head, brain and facial injury for bicyclists of all ages involved in a bicycle crash or fall.

SEARCH STRATEGY

We searched The Cochrane Controlled Trials Register, MEDLINE, EMBASE, Sport, ERIC, NTIS, Expanded Academic Index, CINAHL, PsycINFO, Occupational Safety and Health, and Dissertations Abstracts. We checked reference lists of past reviews and review articles, studies from government agencies in the United States, Europe and Australia, and contacted colleagues from the International Society for Child and Adolescent Injury Prevention, World Injury Network, CDC funded Injury Control and Research Centers, and staff in injury research agencies around the world.

SELECTION CRITERIA

Controlled studies that evaluated the effect of helmet use in a population of bicyclists who had experienced a crash. We required that studies have complete outcome ascertainment, accurate exposure measurement, appropriate selection of the comparison group and elimination or control of factors such as selection bias, observation bias and confounding.

DATA COLLECTION AND ANALYSIS

Five published studies met the selection criteria. Two abstractors using a standard abstraction form independently abstracted data. Odds ratios with 95% CI were calculated for the protective effect of helmet for head and facial injuries. Study results are presented individually. Head and brain injury results were also summarized using meta-analysis techniques.

MAIN RESULTS

No randomized controlled trials were found. This review identified five well conducted case control studies which met our selection criteria. Helmets provide a 63%-88% reduction in the risk of head, brain and severe brain injury for all ages of bicyclists. Helmets provide equal levels of protection for crashes involving motor vehicles (69%) and crashes from all other causes (68%). Injuries to the upper and mid facial areas are reduced 65%.

REVIEWER'S CONCLUSIONS

Helmets reduce bicycle-related head and facial injuries for bicyclists of all ages involved in all types of crashes including those involving motor vehicles.

Pool fencing for preventing drowning in children

BACKGROUND

In most industrialized countries, drowning ranks second or third behind motor vehicles and fires as a cause of unintentional injury deaths to children under the age of 15. Death rates from drowning are highest in children less than five years old. Pool fencing is a passive environmental intervention designed to reduce unintended access to swimming pools and thus prevent drowning in the preschool age group. Because of the magnitude of the problem and the potential effectiveness of fencing we decided to evaluate the effect of pool fencing as a drowning prevention strategy for young children.

OBJECTIVES

To determine if pool fencing prevents drowning in young children.

SEARCH STRATEGY

We used Cochrane Collaboration search strategy of electronic databases, searched reference lists of past reviews and review articles, Cochrane International Register of RCT's, studies from government agencies in the United States and Australia, and contacted colleagues from International Society for Child and Adolescent Injury Prevention, World Injury Network, and CDC funded Injury Control and Research Centers.

SELECTION CRITERIA

In order to be selected a study had to be designed to evaluate pool fencing in a defined population and provide relevant and interpretable data which objectively measured the risk of drowning or near drowning or provided rates of these outcomes in fenced and unfenced pools. The completed studies meeting selection criteria employed a case-control design. No randomized controlled studies have been identified.

DATA COLLECTION AND ANALYSIS

Three published studies met selection criteria. Data were extracted by two reviewers using standard abstract form. Odds ratios with 95% CI, and incidence rates, were calculated for drowning and near-drowning. Attributable Risk percent (AR%) was calculated to report the reduction in drowning due to pool fencing.

MAIN RESULTS

Case control studies which evaluate pool fencing interventions indicate that pool fencing significantly reduces the risk of drowning. Odds ratio for the risk of drowning or near drowning in a fenced pool compared to an unfenced pool is 0.27 95%CI (0.16, 0.47). Isolation fencing (enclosing pool only) is superior to perimeter fencing (enclosing property and pool) because perimeter fencing allows access to the pool area through the house. Odds ratio for the risk of drowning in a pool with isolation fencing compared to a pool with three sided fencing is 0.17 95%CI (0.07, 0.44)

REVIEWER'S CONCLUSIONS

Pool fences should have a dynamic and secure gate and isolate (i.e., four-sided fencing) the pool from the house. Legislation should require isolation fencing with secure, self-latching gates for all pools, public, semi-public and private.

Fit of bicycle safety helmets and risk of head injuries in children

BACKGROUND

Although bicycle helmets are effective in preventing head and brain injury, some helmeted individuals nevertheless sustain head injury. One of the possible reasons may be poor fit of the helmet on the head. This study was undertaken to examine the relationship between helmet fit and risk of injury.

METHODS

1718 individuals who were helmeted riders in a crash were queried on helmet fit and position. A sample of 28 children 2-14 years of age who sustained a head injury while wearing a bicycle helmet and 98 helmeted individuals of the same age treated in the same hospital emergency departments for injuries other than to the head, underwent anthropometric measurements of helmet fit. Measurements were made of the child's head, the helmet, and on a cast made of the child's head.

RESULTS

Individuals whose helmets were reported to fit poorly had a 1.96-fold increased risk of head injury compared with those whose helmets fit well. Children with head injuries had helmets which were significantly wider than their heads compared with children without head injuries. Helmet fit was poorer among males and among younger children.

CONCLUSIONS

Poor fit of helmets may be associated with an increased risk of head injury in children, especially in males. Helmets may not be designed to provide optimal protection.

Domestic violence and primary care. Attitudes, practices, and beliefs

OBJECTIVE

To assess the attitudes and beliefs of the primary care provider team (physicians, physician assistants, nurses, and medical assistants) toward the identification and management of abused patients and perpetrators of domestic violence (DV).

DESIGN

Survey of the health care team using a confidential questionnaire.

SETTING AND SUBJECTS

Five primary care clinics with 240 providers at a large urban health maintenance organization.

RESULTS

The response rate was 86% (206 respondents). Fifty percent of clinicians and 70% of nurses/assistants believed that the prevalence of DV in their practice was 1% or loss; 1 in 10 clinicians and nearly half of nurses/assistants had never identified an abused person; 45% of clinicians never or seldom asked about DV when examining injured patients; and all participants were much less confident in asking about DV than about smoking or consuming alcohol. Twenty-five percent believed the abused person's personality led to the violence; 28% believed they did not have strategies to help abused persons; and 20% were concerned for their personal safety in discussing DV. Only 10% believed they had management information, but 77% had not attended any educational programs on DV in the past year.

CONCLUSIONS

This study provides important information about current knowledge, attitudes, and beliefs of health care providers toward the diagnosis and management of DV. This information should prove useful to all who attempt to design clinical strategies and educational programs to address this issue.

High-speed random access laser tuning

We have developed a technique for laser tuning at rates of 100 kHz or more using a pair of acousto-optic modulators. In addition to all-electronic wavelength control, the same modulators also can provide electronically variable Q-switching, cavity length and power stabilization, chirp and linewidth control, and variable output coupling, all at rates far beyond what is possible with conventional mechanically tuned components. Tuning rates of 70 kHz have been demonstrated on a radio-frequency-pumped CO2 laser, with random access to over 50 laser lines spanning a 17% range in wavelength and with wavelength discrimination better than 1 part in 1000. A compact tuner and Q-switch has been deployed in a 5-10-kHz pulsed lidar system. The modulators each operate at a fixed Bragg angle, with the acoustic frequency determining the selected wavelength. This arrangement doubles the wavelength resolution without introducing an undesirable frequency shift.

Effectiveness of primary and secondary enforced seat belt laws

OBJECTIVE

The objective of this study was to determine the relative efficacy of primary and secondary enforced motor vehicle occupant restraint laws on the outcomes of restraint use, crash-related mortality, and crash-related injuries.

SEARCH STRATEGY

We used the Cochrane Collaboration search strategy to search the following electronic databases: MEDLINE, EMBASE, National Technical Information Service (NTIS), Psyc-INFO, ERIC, Nursing and Allied Health (CINAHL), Transportation Research Information Service (TRIS), and EI Compendex. The reference lists from each potentially eligible study were checked, and knowledgeable people in the field were contacted, for additional leads to published reports.

SELECTION CRITERIA

Studies had to include a comparison of primary enforcement law to no law, secondary enforcement law to no law, or a primary to a secondary law. Any study design was acceptable. Acceptable outcome measures included observed restraint use, and counts or rates of deaths or serious injuries.

DATA COLLECTION

Data were collected using a standard abstract reporting from. Relative differences in outcomes and absolute differences were calculated when possible.

MAIN RESULTS

We identified 48 studies for the review. When places or time periods with primary enforcement laws were compared to those without such laws, the relative prevalence of seat belt use ranged from 1.5 to 4.5; the prevalence differences ranged from 10 to 50 per 100 observed drivers. Secondary laws had smaller effects. Two studies evaluated a change in law from secondary to primary enforcement; this was associated with an increase in belt use 6 months later of 5.3 per 100 observed drivers in Louisiana and 18 per 100 drivers in California. Primary enforcement laws were associated with a relative risk of death in MV crashes of .54 to .97. The reduction in mortality associated with secondary enforcement laws was much more modest, with relative risks estimates of .81 to 1.025. Primary enforcement laws were associated with a relative risk of severe injuries of .20 to .89; the association of secondary enforcement laws with severe injuries was smaller.

CONCLUSIONS

Our review of existing studies suggests that primary enforcement laws are likely to be more effective than secondary laws. However, few studies are of good quality, and quantitative estimates of the relative effect of primary compared with secondary laws are limited.

Systematic reviews of strategies to prevent motor vehicle injuries

BACKGROUND

Information on which strategies have been shown to be effective, which are ineffective, and which strategies have been inadequately evaluated is important for both public policy and future research.

OBJECTIVE

To provide systematic reviews of the literature on important strategies to prevent motor vehicle injuries.

METHODS

The Injury Control Research Centers (ICRCs) funded by the Centers for Disease Control and Prevention identified 9 important motor vehicle injury prevention strategies. A systematic review of the literature in 9 different computerized databases was conducted to identify relevant controlled trials. These were critically reviewed and summarized.

RESULTS

A total of 54,078 citations were reviewed; 1,111 met initial screening criteria. The reports for these citations were obtained and critically reviewed by the ICRCs. Standard criteria for inclusion of articles in the review and for evaluating the methodological quality of the articles were applied. Few randomized controlled trials were found; most controlled studies were either comparisons over time and/or across different populations. Nevertheless, these studies were able to be summarized to provide meaningful conclusions about the effectiveness of various interventions to decrease morbidity and mortality from motor vehicle crashes.

CONCLUSIONS

A large body of literature on motor vehicle injury interventions exists. The summary of this literature will provide useful information to direct policy and future research efforts.

Does the face protect the brain? A case-control study of traumatic brain injury and facial fractures

BACKGROUND

The relationship between facial fractures and traumatic brain injury is controversial. Some studies show an increased risk of brain injury with the presence of facial fractures while others claim that facial fractures protect against brain injury.

OBJECTIVE

To examine the association between facial fractures and traumatic brain injuries.

DESIGN

Case-control study.

SETTING

Subjects were recruited from the emergency departments of 7 hospitals in the Seattle, Wash, area.

PATIENTS

Three thousand eight hundred forty-nine injured bicyclists and 5 scene deaths were identified from March 1, 1992, to August 31, 1994, with complete data available on 3388 bicyclists.

INTERVENTIONS

None.

RESULTS

The study group was composed of 1602 cases with injuries to the head, face, or brain and 1540 control subjects. There were 203 bicyclists with traumatic brain injuries, of whom 62 had an identifiable intracranial injury and 141 suffered a concussion. A total of 81 patients sustained facial fractures. The odds ratio for the risk of intracranial injury associated with facial fractures after adjustment for significant confounders was 9.9 (95% confidence interval, 5.1-19.3). The effect was less strong but still present when all traumatic brain injuries including concussions were considered (odds ratio, 2; 95% confidence interval, 1.1-3.7). No association was found for concussion only.

CONCLUSIONS

This study demonstrates no evidence that facial fractures help prevent traumatic brain injury. Data indicate that facial fractures are markers for increased risk of brain injury.

Prevention of bicycle-related injuries: helmets, education, and legislation

Efforts to reduce the toll of bicycle-related head injuries illustrate how the basic public health principles of surveillance, epidemiologic study, intervention, and evaluation can have a substantial impact on an injury problem, using a variety of injury-prevention strategies. Head injuries are the leading cause of serious morbidity and mortality from bicycle crashes. Helmets have been shown to reduce bicycle-related head injuries for cyclists of all ages involved in all types of crashes including those with motor vehicles. Helmet use has been promoted using educational campaigns, helmet subsidies, and legislation. Careful evaluation of these strategies has shown that these interventions increase helmet use and decrease the incidence of bicycle injuries. The model developed for the prevention of bicycle injuries is widely applicable to other injury problems.

Cytokine-induced nitric oxide formation in normal but not in neoplastic murine lung epithelial cell lines

Cytomix, a mixture of interferon-gamma, tumor necrosis factor-alpha, and interleukin-1beta, induces nitric oxide (NO) production in lung epithelial cell lines. It is not known whether neoplastic transformation alters a cell's ability to form NO in response to cytokines. The present study investigated NO formation in two murine lines of immortalized "normal" (nontumorigenic) lung epithelial cells of alveolar type II origin, E10 and C10, and their sibling spontaneous transformants, E9 and A5. Nontumorigenic cells elaborated much more NO after cytomix exposure than did their tumorigenic counterparts. NO production was prevented by inhibiting protein synthesis and NO synthase and attenuated by dexamethasone. Northern and Western blot analyses of inducible NO synthase (iNOS) demonstrated cytomix-induced induction of iNOS only in nontumorigenic cells. The deficiency in NO production in tumorigenic cells was not associated with reduced iNOS mRNA stability or with differences in cytomix-induced nuclear factor-kappaB activation. Although cytomix caused a greater production of NO in E10 cells than in E9 cells, the same treatment induced equivalent proliferation in both cell lines. These results indicate a specific deficiency in cytokine-induced NO synthesis in transformed murine lung epithelial cells relative to their normal progenitor cells and provide a model for investigating iNOS regulation.

Synthesis and structure-activity relationships of potent and orally active 5-HT4 receptor antagonists: indazole and benzimidazolone derivatives

A series of indole-3-carboxamides, indazole-3-carboxamides, and benzimidazolone-3-carboxamides was synthesized and evaluated for antagonist affinity at the 5-HT4 receptor in the rat esophagus. The endo-3-tropanamine derivatives in the indazole and benzimidazolone series possessed greater 5-HT4 receptor affinity than the corresponding indole analogues. 5-HT4 receptor antagonist affinity was further increased by alkylation at N-1 of the aromatic heterocycle. In a series of 1-isopropylindazole-3-carboxamides, replacement of the bicyclic tropane ring system with the monocyclic piperidine ring system or an acyclic aminoalkylene chain led to potent 5-HT4 receptor antagonists. In particular, those systems in which the basic amine was substituted with groups capable of forming hydrogen bonds showed increased 5-HT4 receptor antagonist activity. While some of these compounds displayed high affinity for other neurotransmitter receptors (in particular, 5-HT3, alpha1, and 5-HT2A receptors), as the conformational flexibility of the amine moiety increased, the selectivity for the 5-HT4 receptor also increased. From this series of compounds, we identified LY353433 (1-(1-methylethyl)-N-[2-[4-[(tricyclo[3.3.1.1(3, 7)]dec-1-ylcarbonyl)amino]-1-piperidinyl]ethyl]-1H-indazole-3- carboxamide) as a potent and selective 5-HT4 receptor antagonist with clinically suitable pharmacodynamics.

Cycle helmets and the prevention of injuries. Recommendations for competitive sport

The scientific evidence that bicycle helmets protect against head, brain and facial injuries has been well established by 5 well designed case-control studies. Additional evidence of helmet effectiveness has been provided from time series studies in Australia and the US. Bicycle helmets of all types that meet various national and international standards provide substantial protection for cyclists of all ages who are involved in a bicycle crash. This protection extends to crashes from a variety of causes (such as falls and collisions with fixed and moving objects) and includes crashes involving motor vehicles. Helmet use reduces the risk of head injury by 85%, brain injury by 88% and severe brain injury by at least 75%. Helmets should be worn by all riders whether the cyclist is a recreational rider or a serious competitor engaged in training or race competition. The International Cycling Federation (ICF) should make the use of helmets compulsory in all sanctioned races.

Comparative toxicity of eugenol and its quinone methide metabolite in cultured liver cells using kinetic fluorescence bioassays

Comparative kinetic analyses of the mechanisms of toxicity of the alkylphenol eugenol and its putative toxic metabolite (quinone methide, EQM) were carried out in cultured rat liver cells (Clone 9, ATCC) using a variety of vital fluorescence bioassays with a Meridian Ultima laser cytometer. Parameters monitored included intracellular GSH and calcium levels ([Ca2+]i), mitochondrial and plasma membrane potentials (MMP and PMP), intracellular pH, reactive oxygen species (ROS) generation, and gap junction-mediated intercellular communication (GJIC). Cells were exposed to various concentrations of test compounds (1 to 1000 microM) and all parameters monitored directly after addition at 15 s intervals for at least 10 min. Eugenol depleted intracellular GSH, inhibited GJIC and generation of ROS, and had a modest effect on MMP at concentrations of 10 to 100 microM. At high concentrations (1000 microM), eugenol also affected [Ca2+]i, PMP, and pH. Effects of EQM were seen at lower concentrations (1 to 10 microM). The earliest and most potent effects of either eugenol or EQM were seen on GSH levels and GJIC. Coadministration of glutathione ethyl ester enhanced intracellular GSH levels by almost 100% and completely protected cells from cell death caused by eugenol and EQM. These results suggest that eugenol mediates its hepatotoxic effects primarily through depletion of cytoprotective thiols and interference in thiol-dependent processes such as GJIC. Furthermore, our results support the hypothesis that the toxic effects of eugenol are mediated through its quinone methide metabolite.

A training program to improve domestic violence identification and management in primary care: preliminary results

Domestic violence as encountered in day-to-day practice is greatly underidentified. It is estimated that only 3% of cases are presently being identified, and practitioners are uncertain of what to do if a case is discovered. In this paper, a training program to improve identification and management of domestic violence (DV) in primary care and the providers' responses to the program are described. A multimodal training program was undertaken to demonstrate and practice the incorporation of didactic content into practice for the health care teams. Two medical centers from a large staff-model HMO were chosen at random from five volunteering for training. The entire adult health care medical center teams, including physicians, physician assistants, RNs, LPNs, medical assistants, and receptionists, were the recipients of the training. Assessment of provider valuation of the components of the training program was performed by administering a standardized 5-point Likert-scaled questionnaire 9 months after the training. This time interval was chosen because we were interested in lasting program effects. Core didactic content, such as the epidemiology of DV, identification and management of victims and batterers, and legal issues, was highly rated. Delivery of the content through role-playing, start-stop videos and presentations by former victims received lesser but solid support. Follow-up assessment 9 months post training demonstrates solid support for many components of the program: highest for specific information content areas, but strong for techniques and processes. The training program appears to be a promising method to improve provider skills in DV management.

Differential susceptibility of tracheal contraction to nonadrenergic noncholinergic relaxation

Studies of nonadrenergic noncholinergic inhibitory (NANCi) nerve-induced relaxations routinely examine relaxations in airway tissue in which tone has been established. Little is known about the ability of NANCi nerve stimulation to prevent airway smooth muscle contraction. The present study compares the capacity of NANCi nerve stimulation to prevent or reverse airway smooth muscle contraction. NANCi nerves in the trachea from ovalbumin-sensitized guinea pigs were subjected to electrical field stimulation (EFS, 10 Hz, 0.3 ms, 10 V, 35 min) initiated before or after induction of tone with antigen or histamine. In tissues precontracted with histamine or antigen, EFS elicited a rapid relaxation which peaked within the first 5 min and stabilized by 20 to 35 min. The peak relaxation was smaller in tissues precontracted with antigen, an effect that was not prevented by tissue treatment with a nitric oxide synthase inhibitor. In contrast, the stabilized level of NANCi relaxation did not differ between histamine- or antigen-contracted tissues. Activation of NANCi nerves prior to induction of tone also resulted in inhibition of the contractile actions of histamine and antigen. However, the stabilized level of tone induced by a contractile agonist added after initiation of EFS was greater than the stabilized tone caused by EFS in tissues already contracted with the same agonist. Relaxations elicited by S-nitrosoglutathione were reduced in antigen-precontracted tissues whereas vasoactive intestinal peptide-induced relaxant responses were similar in antigen- and histamine-precontracted tissues. Results of this study suggest that NANCi nerve activation is more effective at relaxing established airway smooth muscle tone than at preventing airway smooth muscle contraction. Further, the results suggest that the difference in NANCi activity in antigen-precontracted tissues cannot be ascribed solely to reductions in the nitric oxide-dependent component of the response.

Absence of tachykinin involvement in leukotriene D4 and antigen-induced contraction of guinea pig isolated bronchus

In guinea pig airways, contractions induced by leukotriene D4 or antigen are thought to be mediated primarily by an action of the agonist or of released mast cell-derived mediators directly on the airway smooth muscle cell. An indirect contractile action mediated by endogenous tachykinins also has been described for both of these stimuli. The present study evaluated the contribution of endogenous tachykinins to ovalbumin- and leukotriene D4-induced contractions in the guinea pig bronchus by modulating the concentrations of tachykinins within the tissues and by using neurokinin receptor antagonists. Acute depletion of tachykinins with capsaicin had no effect on responses elicited by either stimulus. Similarly, tetrodotoxin treatment failed to influence leukotriene D4-induced contractions. Inhibitors of neutral endopeptidase (thiorphan) and angiotensin-converting enzyme (lisinopril) enhanced neurally mediated tachykininergic responses and potentiated leukotriene D4. The latter effect persisted in the presence of tetrodotoxin or the neurokinin antagonists CP99994 and SR48968 and in tissues treated acutely with capsaicin. The potentiation was absent, however, from bronchi incubated with L-cysteine. Ovalbumin-induced contractions were unaltered by inhibition of neutral endopeptidase and angiotensin-converting enzyme. These observations suggest that tachykinins are not involved in mediation of leukotriene D4- or antigen-induced contractions of the guinea pig bronchus. The ability of protease inhibitors to potentiate leukotriene D4 but not antigen-induced responses is therefore ascribed to inhibition of bioinactivation of leukotriene D4 to leukotriene E4.

Effect of speckle on lidar pulse-pair ratio statistics

The ratio of temporally adjacent lidar pulse returns is commonly used in differential absorption lidar (DIAL) to reduce correlated noise. These pulses typically are generated at different wavelengths with the assumption that the dominant noise is common to both. This is not the case when the mean number of laser speckle integrated per pulse by the lidar receiver is small (namely, less than 10 speckles at each wavelength). In this case a large increase in the standard deviation of the ratio data results. We demonstrate this effect both theoretically and experimentally. The theoretical value for the expected standard deviation of the pulse-pair ratio data compares well with the measured values that used a dual CO(2) laser-based lidar with a hard target. Pulse averaging statistics of the pulse-pair data obey the expected varsigma(1)/ radicalN reduction in the standard deviation, varsigma(N), for N-pulse averages. We consider the ratio before average, average before ratio, and log of the ratio before average methods for noise reduction in the lidar equation. The implications of our results are discussed in the context of dual-laser versus single-laser lidar configurations.

Immunochemical visualization and identification of rat liver proteins adducted by 2,6-di-tert-butyl-4-methylphenol (BHT)

Several alkylphenols (e.g., 2,6-di-tert-butyl-4-methylphenol, BHT) form reactive quinone methide intermediates (e.g., 2,6-di-tert-butyl-4-methylene-2,5-cyclohexadienone, BHT-QM) upon oxidation by cellular enzymes. In order to pursue the role of protein alkylation in alkylphenol toxicity, we used an immunochemical approach to identify protein targets alkylated by BHT. Synthetic BHT-N-acetylcysteine (BHT-NAC) was coupled to keyhole limpet hemocyanin and used as an antigen from which polyclonal antibodies were raised in New Zealand white rabbits. Rabbit serum contained an antibody which was highly specific for BHT-NAC, as determined by competitive ELISA. The BHT antibody was used as a probe to look for the presence of BHT-protein adducts in in vitro incubations with rat liver microsomes or tissue slices and also in vivo in liver tissue from male Sprague-Dawley rats exposed to BHT. Western blotting of protein gels revealed BHT-dependent protein alkylation over a wide molecular weight range. Prominent recurrent bands were observed at approximately 34.5, 52, 64.5, 74, and 97 kDa. Detection of adducts was inhibited in microsomal incubations by cytochrome P450 inhibitors, deuterated BHT, and the omission of NADPH. Similar protein alkylation patterns were observed in rat liver microsomes exposed to synthetically prepared BHT-QM as in the enzyme-mediated incubations. In rats gavaged with up to 1000 mg/kg BHT, the amount of protein alkylation observed was maximal at 24 h postdosing and was dose-dependent. Two alkylated proteins were isolated and identified by N-terminal sequencing: a mitochondrial beta-oxidation enzyme, enoyl-CoA hydratase, and a plasma membrane/cytoskeletal linker protein from the ezrin/moesin/radixin family.

Damage to bicycle helmets involved with crashes

The objective was to evaluate the relationship between helmet damage and head injuries in helmeted bicyclists in a sub-study of a large case-control study of bicycle injuries and helmet effectiveness. The setting consisted of seven hospital emergency departments in Seattle, WA. Hospitalized patients and medical examiners cases were included. The participants in the study were helmeted bicyclists who suffered a head injury or who damaged or hit their helmet in a crash. The Snell Memorial Foundation laboratory evaluated the helmets, blinded to crash circumstance and injury diagnosis. Damage was scored on a five-point scale (0 = none to 4 = destroyed). The damage location for each helmet was coded into regions (six longitudinal and three latitudinal) and mapped onto a three-dimensional CAD (computer-aided design) model of a helmet. The same procedure was also followed for injury location, which was mapped onto a three-dimensional ISO (International Organization for Standardization) headform for visualization of head-injury distribution. 785 helmeted subjects met the criteria for inclusion in the sub-study, and 527 helmets were purchased and evaluated (67%). 316 (60%) of the helmets had no or minimal damage, and 209 (39.7%) had significant damage (score 2, 3 or 4). Helmet types were 49.7% hard shell, 34.2% thin shell and 16.1% no shell. The risk of head and brain injury increased if the helmet was destroyed: OR = 5.3 (95% CI 2.9, 9.9) and OR = 11.2 (95% CI 3.5, 37.9), respectively. A high proportion of helmet impacts were along the front edge of the helmet, with a preponderance of head injuries in the same region. The large number of impacts to the front rim of the helmet, combined with the substantial number of riders with injuries to the forehead, indicate that some helmets, because of poor fit or wearing style, expose the forehead to injury. In addition, the data indicate that for a small proportion of injuries, the energy to the helmet may exceed design limits.

Epidemiology of bicycle injuries and risk factors for serious injury

OBJECTIVE

To determine the risk factors for serious injury to bicyclists, aside from helmet use.

DESIGN

Prospective case-control study.

SETTING

Seven Seattle area hospital emergency departments and two county medical examiner's offices.

PATIENTS

Individuals treated in the emergency department or dying from bicycle related injuries.

MEASUREMENTS

Information collected from injured bicyclists or their parents by questionnaire on circumstances of the crash; abstract of medical records for injury data. Serious injury defined as an injury severity score > 8.

ANALYSIS

Odd ratios computed using the maximum likelihood method, and adjusted using unconditional logistic regression.

RESULTS

There were 3854 injured cyclists in the three year period; 3390 (88%) completed questionnaires were returned 51% wore helmets at the time of crash. Only 22.3% of patients had head injuries and 34% had facial injuries. Risk of serious injury was increased by collision with a motor vehicle (odds ratio (OR) = 4.6), self reported speed > 15 mph (OR = 1.2), young age (< 6 years), and age > 39 years (OR = 2.1 and 2.2 respectively, compared with adults 20-39 years). Risk for serious injury was not affected by helmet use (OR = 0.9). Risk of neck injury was increased in those struck by motor vehicles (OR = 4.0), hospitalized for any injury (OR = 2.0), and those who died (OR = 15.1), but neck injury was not affected by helmet use.

CONCLUSIONS

Prevention of serious bicycle injuries cannot be accomplished through helmet use alone, and may require separation of cyclists from motor vehicles, and delaying cycling until children are developmentally ready.

Injuries involving off-road cycling

BACKGROUND

Data on injuries due to off-road bicycling are scarce, but do indicate that injuries in this sport are frequent. We examined the pattern of injuries to off-road riders as part of a larger study of bicycle injuries and helmet use.

METHODS

We undertook a prospective study of bicycle-related injuries identified at seven emergency departments in Seattle, Washington, between March 1992 and August 1994. Hospitalized patients and medical examiners' cases were included. Detailed questionnaires and abstraction of all medical records provided information on crash and rider characteristics and injury type and severity.

RESULTS

A total of 3390 injured riders participated, representing an 88% response rate. Of all injured cyclists, 127 (3.7%) were injured riding "off road." Seventy-three percent of off-road cyclists were 20 to 39 years of age, and 86.6% were male. Helmet use was 80.3% for off-road cyclists as compared with 49.5% for other cyclists. The number of head and face injuries for the off-road cyclists was only 40% of the number incurred by other cyclists. Four percent of off-road cyclists had severe injuries (injury Severity Score > 8), and 6.3% were hospitalized, compared with 6.8% and 9.4%, respectively, of other cyclists.

CONCLUSIONS

The majority of off-road bicycling injuries are minor. Off-road cyclists are less likely to have head and face injuries than other cyclists and are more likely to wear helmets.

Bike speed measurements in a recreational population: validity of self reported speed

OBJECTIVE

Speed at the time of a bicycle crash is an important determinant of the amount of energy transmitted. Controlling for speed is thus important in the evaluation of outcomes and effectiveness of intervention strategies. This study was conducted to evaluate the accuracy of self reported speed in a population of recreational cyclists.

METHODS

Children's and adults' bicycle speeds were measured with a radar gun as they rode along a closed road at weekend recreational events. Cyclists were then stopped and asked to estimate their speed. Measured speed, cyclist's estimate of their speed, age, and sex were documented. Parents were also asked to estimate their child's speed.

RESULTS

One hundred and fifty two cyclists from 4 to 80 years of age participated. Seventy per cent were children 13 years of age or younger. The mean (SD) speed of this group was 8.9 (2.5) mph. Cyclists age 14 and older were traveling at a mean speed of 9.7 (2.87) mph. Estimated speeds were significantly higher than measured speeds for this older group, but there was no significant difference between mean measured and estimated speeds for the younger riders. There was also no significant difference between measured and estimated speed for males and females. Parents estimated their child's speed quite accurately.

CONCLUSIONS

Self reported speeds for children were in close agreement with measured speeds and, thus, are sufficiently accurate to be a useful measure of crash severity in evaluating helmet effectiveness.

Effectiveness of bicycle safety helmets in preventing head injuries. A case-control study

OBJECTIVES

To examine the protective effectiveness of bicycle helmets in 4 different age groups of bicyclists, in crashes involving motor vehicles, and by helmet type and certification standards.

RESEARCH DESIGN

Prospective case-control study

SETTING

Emergency departments (EDs) in 7 Seattle, Wash, area hospitals between March 1, 1992, and August 31, 1994.

PARTICIPANTS

Case subjects were all bicyclists treated in EDs for head injuries, all who were hospitalized, and all who died at the scene. Control subjects were bicyclists treated for nonhead injuries.

MAIN RESULTS

There were 3390 injured bicyclists in the study; 29% of cases and 56% of controls were helmeted. Risk of head injury in helmeted vs unhelmeted cyclists adjusted for age and motor vehicle involvement indicate a protective effect of 69% to 74% for helmets for 3 different categories of head injury: any head injury (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.26-0.37), brain injury (OR, 0.35; 95% CI, 0.25-0.48), or severe brain injury (OR, 0.26; 95% CI, 0.14-0.48). Adjusted ORs for each of 4 age groups (<6 y, 6-12 y, 13-19 y, and > or = 20 years) indicate similar levels of helmet protection by age (OR range, 0.27-0.40). Helmets were equally effective in crashes involving motor vehicles (OR, 0.31; 95% CI, 0.20-0.48) and those not involving motor vehicles (OR, 0.32; 95% CI, 0.20-0.39). There was no effect modification by age or motor vehicle involvement (P=.7 and P=.3). No significant differences were found for the protective effect of hard-shell, thin-shell, or no-shell helmets (P=.5).

CONCLUSIONS

Bicycle helmets, regardless of type, provide substantial protection against head injuries for cyclists of all ages involved in crashes, including crashes involving motor vehicles.

Firearm patient education and firearm regulation: health care providers' attitudes and practices

A survey of two large HMOs was conducted to assess health care providers' attitudes and practices regarding firearm patient education, firearm patient counselling, and firearm regulation. Survey results were intended to provide background data on barriers to be addressed and opportunities to be used in developing day-to-day office practice interventions to reduce enrollees' risk of firearm injury.

Metabolism and toxicity of 4-hydroxyphenylacetone in rat liver slices: comparison with acetaminophen

Acetaminophen is oxidized by cytochrome P450 to a reactive quinone imine, N-acetyl-p-benzoquinone imine, which is thought to be responsible for its hepatotoxic effects. 4-Hydroxyphenylacetone (4-HPA) is a structural analog of acetaminophen in which the amine group is replaced by a methylene group. Following a similar metabolic pathway, 4-HPA would be oxidized to form a reactive quinone methide intermediate. We compared the metabolism and toxicity of 4-HPA and acetaminophen in liver microsomes and precision-cut liver slices from male Sprague-Dawley rats. Both 4-HPA and acetaminophen formed glutathione conjugates in microsomal incubations. 4-HPA formed diastereomeric glutathione conjugates, which is consistent with the formation of an intermediate quinone methide. The rate of conjugate formation with 4-HPA was 8.5-fold greater than that with acetaminophen. In rat liver slices a concentration of 5 mM 4-HPA killed approximately 50% of hepatocytes after 6 hr of incubation, whereas acetaminophen was not toxic at concentrations up to 50 mM. N-Acetylcysteine protected slices from 4-HPA-induced toxicity, whereas phenobarbital enhanced metabolism and toxicity. In summary, 4-HPA is more hepatotoxic than acetaminophen, and this may be the result of differences in the metabolic rate and/or the type of reactive intermediate formed.

Studies on the mechanism of hepatotoxicity of 4-methylphenol (p-cresol): effects of deuterium labeling and ring substitution

We recently observed that 4-methylphenol (p-cresol) is toxic to rat liver tissue slices. A possible mechanism involves biotransformation of 4-methylphenol to a reactive quinone methide intermediate which covalently binds to cellular macromolecules and elicits cytotoxicity. In order to obtain further evidence for this proposed mechanism, we studied the effects of deuterium-labeled 4-methylphenol (4-[alpha, alpha, alpha-d3]-methylphenol), and the presence of various ring substituents, on the metabolism and toxicity of 4-methylphenol in precision cut liver slices prepared from male Sprague-Dawley rats. Deuterium-labeled 4-methylphenol was significantly less toxic than the parent compound in rat liver slices (LC50 = 3.36 vs. 1.31 mM, respectively). In addition, the deuterium-labeled compound was metabolized to a reactive intermediate (measured as glutathione conjugate formation) at a slower rate than that of 4-methylphenol in both liver slices and liver microsomal incubations. The presence of electron withdrawing substituents (2-chloro or 2-bromo) markedly enhanced both metabolism and toxicity, with the exception of 2,6-dibromocresol, which was similar to cresol in terms of rate of metabolism and toxicity. Conversely, the presence of electron donating substituents (2-methoxy, 2-methyl or 2,6-dimethyl) diminished metabolism and toxicity. In addition, methylation of the hydroxyl group to form 4-methylanisole, greatly reduced toxicity. These results support the hypothesis that the toxicity of 4-methylphenol is dependent on the formation of a reactive quinone methide intermediate.