Defining the concept of 'tick repellency' in veterinary medicine

Although widely used, the term repellency needs to be employed with care when applied to ticks and other periodic or permanent ectoparasites. Repellency has classically been used to describe the effects of a substance that causes a flying arthropod to make oriented movements away from its source. However, for crawling arthropods such as ticks, the term commonly subsumes a range of effects that include arthropod irritation and consequent avoiding or leaving the host, failing to attach, to bite, or to feed. The objective of the present article is to highlight the need for clarity, to propose consensus descriptions and methods for the evaluation of various effects on ticks caused by chemical substances.

Examination of the impact of airbags on renal injury using a national database

BACKGROUND

Little is known about preventative measures to lessen solid organ injury in motor vehicle collisions (MVCs). To evaluate the efficacy of airbags in reducing renal injuries in MVC, we analyzed renal injury rates in vehicles with and without airbags using the Crash Injury Research and Engineering Network (CIREN) database.

STUDY DESIGN

The CIREN database was queried for MVC and renal injury from 1996 to September 2008. CIREN is weighted toward late model vehicles and selects more severely injured patients. Search fields were primary direction of force (PDOF), presence of airbags, and location of airbags (steering wheel, instrument panel, seat back, door panel, and roof-side curtain). Abdominal Abbreviated Injury Score was converted to AAST renal injury grade. Renal injury rates were compared between vehicles with and without frontal and side airbags.

RESULTS

We reviewed 2,864 records and identified 139 renal injuries (28.9% AAST grade III to V). In MVCs with renal injuries, frontal impact was 54.7% of total (n = 76) and side impact was 45.3% of total (n = 63). Most occupants in frontal impact MVCs had exposure to a steering wheel airbag (74.9%); 16.6% had an instrument panel (passenger) airbags. In side impact MVCs, 32.2% of occupants had a side airbag. Compared with the non-airbags cohort, frontal airbags and side airbags were associated with a 45.3% and 52.8% reduction in renal injury, respectively.

CONCLUSIONS

Passengers in automobiles with frontal and side airbags have a reduced rate of renal injury compared with those without airbags. Our data support further study of the role of airbags in reducing renal injury after MVC.

Mortality and injury patterns associated with roof crush in rollover crashes

BACKGROUND

In the United States, a significant number of spine injuries, traumatic brain injuries (TBI), and deaths result from motor vehicle rollover crashes each year though they make up a small percentage of total crashes. We sought to explore the relationship between these injuries and the degree of roof crush.

METHODS

We searched the NASS CDS database for belted, adult (> or =16), non-middle seat passengers involved in rollover crashes from 1993 to 2006. We also searched the CIREN database for illustrative cases. Logistic regression was used to evaluate the relationship between different levels of roof crush and mortality, severe injury (AIS > or = 3) to the spine, spinal cord, and head injury.

RESULTS

The risk of mortality, TBI, and spine injury all increased as the degree of roof crush increased. For mortality increased risk occurred at >15 cm [15-30 cm: OR 2.089 (95% CI: 1.461-2.987); >30 cm: OR 6.301 (95% CI: 4.369-9.087)]. For TBI, increased risk was seen above 15 cm crush [15-30 cm: OR 1.52 (95% CI: 1.045-2.21); >30 cm: OR 3.672 (95% CI: 2.456-5.490)]. For spine injury increased risk was seen above 8 cm crush [8-15 cm: OR 1.968 (95% CI 1.273-3.043); 15-30 cm: OR 2.530 (95% CI 1.634-3.917); > or =30 cm OR 2.682 (95% CI 1.474, 4.877). Results were similar across the different statistical models.

CONCLUSION

There is an association between the degree of roof crush and mortality, spine injury, and head injury in rollover crashes.

Birth defects in the sons and daughters of women who were exposed in utero to diethylstilbestrol (DES)

Prenatal exposure to diethylstilbestrol (DES) is associated with adverse health outcomes, including anatomic anomalies of the reproductive tract in women and of the genitourinary tract in men. The mouse model, which replicates many DES-related effects seen in humans, suggests that prenatal DES exposure causes alterations that may affect the next generation of offspring. We asked women participating in a large, multi-centre study of prenatal DES exposure to report birth defects occurring among 4029 sons and 3808 daughters (i.e., the third generation). A subcohort of 793 third generation daughters was also queried for birth defects. We used logistic regression models to generate odds ratio and 95% confidence intervals for the association between prenatal DES exposure in the mother and birth defects in the offspring. Based on the mothers' reports, overall birth defects were elevated in the sons (OR = 1.53; 95% CI = 1.04, 2.23) and in the daughters (OR = 2.35; 95% CI = 1.44, 3.82). Most estimates of association were imprecise, but daughters appeared to have an excess of heart conditions (OR = 4.56; 95% CI = 1.27, 16.34). Our data suggest a possible association between the mother's prenatal DES exposure and birth defects in their offspring, particularly in daughters. We cannot, however, rule-out the possible influence of reporting bias. In particular, the exposed daughters' elevated risk of cardiac defects may be as a result of the underreporting of these conditions by unexposed mothers.

Effects of gonadectomy and hormone replacement on a spontaneous novel object recognition task in adult male rats

Recent studies in adult male rats have shown that gonadal hormones influence performance on certain working memory and other types of cognitive tasks that are sensitive to lesions of the medial and/or orbital prefrontal cortices. This study asked whether gonadal hormone modulation of prefrontal cortical function in males also extends to the perirhinal division of the rat prefrontal cortex. Specifically, sham-operated control, gonadectomized, and gonadectomized rats supplemented with testosterone propionate or estradiol were tested on a spontaneous novel object recognition task, a paradigm where performance has been shown to be impaired by perirhinal cortical lesions. Using analyses of variance, regression analyses and post-hoc testing to evaluate group differences, it was found that during both the sample and test trials of the task all four groups spent similar absolute and proportional amounts of time ambulating, rearing, stationary, and exploring the two objects present. All groups also explored each of the two identical objects present during sample trials equally. However, during the test trials, only the control and gonadectomized rats given testosterone showed the expected increase in exploration of the novel objects presented, whereas the gonadectomized and gonadectomized, estradiol-supplemental groups continued to explore the novel and familiar objects equally. That regression analyses also identified significant correlations between low bulbospongiosus muscle weight and impaired novel vs. familiar object discrimination further indicates that gonadectomy in adult male rats adversely affects spontaneous novel object recognition in an androgen-sensitive, estrogen-insensitive manner.

Comparison of mid-block and intersection-related left turn collisions

OBJECTIVES

To evaluate the factors that might influence an occupant's injury severity during a left turn movement.

METHODS

We used the National Automotive Sampling System Crashworthiness Data System (1995-2005) to compare crash characteristics and injury outcome between intersection and midblock left turn collisions.

RESULTS

A total of 7,396 collisions were evaluated. Traffic control devices were present in 82% of intersection and 10% of mid-block collisions. After adjustment for potential confounding variables, drivers' injury severity was not significantly associated with the crash location. However, front seat passengers in mid-block collisions had 72% higher odds of experiencing an injury with injury severity score > or =9 (odds ratio: 1.72, 95% confidence interval: 1.09-2.69). Our analysis did not show that drivers or passengers in larger vehicles, e.g., sport utility vehicles and mini-vans, were at lower risk of more severe injuries in comparison to the car occupants in sedans.

CONCLUSION

We found that in comparison to intersection-related left turn collisions, mid-block crashes are associated with more severe injuries for front seat passengers. Furthermore, size of the turning vehicle was not significantly associated with injury severity for drivers or front seat passengers.

Renal injury mechanisms of motor vehicle collisions: analysis of the crash injury research and engineering network data set

PURPOSE

Injury prevention requires efficient diagnosis and management, and knowledge of collision kinematics may allow first responders to triage victims earlier based on crash scene assessment. We identified possible collision patterns and vehicle interior components that may have a role in kidney injury following motor vehicle collision.

MATERIALS AND METHODS

A total of 115 cases (131 renal injuries) were identified in the multicenter Crash Injury Research and Engineering Network database. For each case a crash investigation was performed, identifying vehicle kinematic characteristics, vehicle damage profile and an assessment of the interior compartment to determine points of occupant contact and restraint system use. A multidisciplinary team reviewed each case to establish a probable mechanism for all injuries sustained. Review of the medical record was performed to identify subject demographics and injury characteristics. Cases were analyzed based on frontal vs side impact.

RESULTS

Of the subjects 52% were male. Mean age was 36.1 years and median injury severity score was 33. Overall injuries were low grade in 72.5% of patients, 30% were unrestrained and 47.6% of collisions were side impact. No difference was observed between frontal and lateral collisions with respect to renal injury severity. For frontal impact the seat belt was the source in 26 of 29 renal injuries (90%) and 12 of 15 unrestrained cases (80%) were due to direct impact with the steering column. Of 131 side impact injuries 62 were attributable to impact with lateral compartment elements. Side impact injuries were associated with lateral door panel impact (41 of 61) with the armrest accounting for 22. The mean lateral compartment intrusion was 29.6 cm. No grade V injuries occurred when vehicle intrusion was less than 30 cm. The mean change in velocity for frontal and lateral collisions was 24.0 and 31.5 mph, respectively (p <0.05). In frontal collisions the change in velocity for kidney injuries sourced to the steering wheel vs seat belt injuries was statistically greater (41.5 vs 28.4 mph, p = 0.05).

CONCLUSIONS

Renal injury in frontal and side impact collisions appears to occur after direct impact from objects in the vehicle compartment. For frontal crashes occupant acceleration into the seat belt or steering wheel seems to result in renal injuries. Side impact injuries occur when the vehicle side panel intrudes into the compartment, striking the occupant. Further collision evaluation in larger data sets is required to substantiate our findings.

Do initial radiographs agree with crash site mechanism of injury in pelvic ring disruptions? A pilot study

OBJECTIVE

Direction of injury force inferred from pelvic radiographs may be used in trauma care to predict associated injuries and guide intervention. Our objective was to compare injury direction determined from anteroposterior (AP) pelvic radiographs with injury forces determined from crash site investigation.

MATERIALS AND METHODS

We studied all 28 subjects from the Crash Injury Research Engineering Network (CIREN) database who met inclusion criteria of pelvic ring disruption, single-event crash, restrained front-seat occupant, diagnostic-quality pelvic radiography, and complete crash investigation data. Assessment of diagnostic quality of pelvic radiography was made by 2 radiologists who were blinded to all other subject information. Crash site investigation data included principal direction of force (PDOF), crash magnitude, and passenger compartment intrusion. An orthopedic trauma surgeon and a fellowship-trained emergency radiologist independently assessed the pelvic radiographs to determine the injury PDOF and the Young-Burgess and Tile fracture classifications, with disputes resolved by an additional emergency radiologist. Agreement between injury forces and pelvic radiographs was assessed using the kappa statistic.

RESULTS

The PDOF was anterior in 9 (32%) and lateral in 19 (68%) subjects. The readers agreed with the crash primary direction of force in 21 (75%) subjects (kappa=0.42). In subjects with lateral PDOF, agreement was 89% (17/19) compared to 44% for anterior PDOF (4/9). Interobserver agreement for the Young and Tile classification schemes was moderate (weighted kappa 0.44 and 0.54, respectively).

CONCLUSION

Crash site investigation and pelvic radiography may provide conflicting information about primary direction of injuring forces. Presumed anterior impact based on PDOF is not in consistent agreement with the pattern of injury evident on the AP pelvic radiograph.

Reducing primary and secondary impact loads on the pelvis during side impact

OBJECTIVE

The objective of the study was to determine which vehicle factors are significantly related to pelvic injury in side impact collisions. Identification of relevant parameters could aid in the reduction of these injuries.

METHOD

Side impact crashes from the CIREN database were separated into those in which the occupant sustained a pelvic fracture and those in which no pelvic fracture occurred, although all occupants had serious injuries. A multibody MADYMO model was created of a USDOT SINCAP (U.S. Department of Transportation Side Impact New Car Assessment Program) test of a vehicle with a large center console.

RESULTS

From a study of 113 side impact crashes in the ciren database, nearside occupants with pelvic fractures (n = 78) had (i) more door intrusion (mean, 37 vs. 32 cm, p = 0.02) than those who had serious injuries, but not pelvic fractures (ii) a greater likelihood that the lower border of the door intruded more than the upper part (40% vs. 18%, p < 0.025); and (iii) a greater likelihood that their vehicle had a center console (47 vs. 17%, p < 0.005). Other parameters such as occupant age, weight, gender, vehicle weight, and struck vehicle speed change were not significantly different. MADYMO modeling showed that with a center console, an initial positive pelvic acceleration occurred at about 30 msec, followed at about 45 msec by a second acceleration peak in the opposite direction. Reducing console stiffness reduced the second acceleration but not the initial peak. Allowing the seat to translate laterally when contacted by the door reduced the initial pelvic acceleration by 50% and eliminated the second acceleration peak.

CONCLUSIONS

Redesigning the center console using less stiff materials and allowing some lateral translation of the seat could aid in reducing pelvic injuries in side impact collisions.

Pain-related activation of leukocyte cellular adhesion molecules: preliminary findings

BACKGROUND/AIMS

Acute adrenergic stressors have been found to activate neuroendocrine pathways that can alter leukocyte migration and activity. Leukocyte migration is known to affect the pathophysiology of inflammatory disease processes. This study examined the effects of acute experimental pain on catecholamine and cortisol levels and leukocyte expression of cellular adhesion molecules.

METHODS

Healthy subjects (n = 10) underwent 45 min of acute experimental pain using earlobe electrical stimulation. Measures included sensory and affective pain responses, perceived stress, circulating levels of catecholamines, cortisol, and expression of integrin (CD11a+) cellular adhesion molecules on leukocyte subsets. Data were collected at baseline, after 22.5 and 45 min of pain, and 180 min after pain cessation.

RESULTS

Experimental pain acutely increased circulating levels of epinephrine, along with increases in the number of CD8+CD11a+ leukocytes and the density of CD11a molecules on CD8+ cells. Positive correlations were found between pain and stress scores, and the number of CD8+CD11a+ leukocytes.

CONCLUSION

Acute pain induces elevated cellular adhesion molecule expression on leukocytes, which has possible implications for increasing leukocyte infiltration and disease exacerbation in patient populations with inflammatory syndromes.

Air Bag-Induced Orbital Blow-Out Fractures

RATIONALE

Although air bags have decreased the risk of serious injury from motor vehicle crashes, their deployment is not innocuous and can result in injury. The force of the deploying air bag can cause orbital blow-out fractures. We investigated the circumstances that predispose a crash occupant to this particular injury.

STUDY DESIGN

The authors conducted a case series.

METHODS

A total of 150 orbital fractures occurred among 2,739 occupants in crashes included in the Crash Injury Research and Engineering Network (CIREN) database from January 1997 to July 2005. Ten orbital blow-out fractures attributed solely to air bag deployment were extracted and four reported in depth. Occupant, vehicle, and crash characteristics were reviewed for predisposing similarities and to investigate the mechanism of injury.

RESULTS

All crashes had air bag deployment and a frontal or near-frontal principle direction of force. Nine of 10 injured occupants were positioned within the air bag's deployment zone at the time of impact as a result of a forward seat track position, falling asleep at the wheel, being unrestrained, or having decelerated before impact. Six of 10 occupants experiencing orbital blow-out fractures were of shorter than average height. Based on rigorous crash reconstructions, the orbital blow-out injuries were felt to be causally related to air bag deployment.

CONCLUSION

Air bag deployment may result in orbital blow-out fractures. Occupants positioned in close proximity to the air bag during its deployment phase appear to be at increased risk for orbital blow-out fractures.

Turning at intersections and pedestrian injuries

OBJECTIVE

To evaluate if precrash vehicle movement is associated with the severity of pedestrian injury.

METHODS

We used comprehensive information on pedestrian, vehicle, and injury-related characteristics gathered in the Pedestrian Crash Data Study (PCDS), conducted by the National Highway Traffic Safety Administration (NHTSA) (1994-1998). The odds ratio of severe injuries (injury severity score >/= 15) and crash fatality rate for right- and left-turn collisions at intersection compared with straight vehicle movement were compared using a logistic regression model and taking into consideration the type of vehicle and age of the pedestrians as potential effect modifiers. Later we evaluated the intermediate effect of impact speed on the association by adding it to the logistic regression model.

RESULTS

Of 255 collisions eligible for this analysis, the proportion of pedestrian hit during straight movement, right turns, and left turns were 48%, 32%, and 10%, respectively. Sixty percent of the pedestrians in left-turn crashes and 67% of them in right-turn collisions were hit from their left side. For straight movements the pedestrians were equally likely to be struck beginning from the left or right side of the street. After adjustment for pedestrian's age, vehicle movement was a significant predictor of severe injuries (p < 0.0001) and case fatality (p = 0.003). The association between vehicle precrash movement and severe injuries (p = 0.551) and case fatality (p = 0.912) vanished after adjusting for impact speed. This indicated that the observed association was probably the result of the difference in impact speed and not the precrash movement of the vehicle.

CONCLUSION

Pedestrian safety interventions that aim at environmental modifications, such as crosswalk repositioning, might be the most efficient means in reducing right- or left-turn collisions at intersection, while pedestrians' behavioral modifications should be the priority for alleviating the magnitude of the collisions that happen in vehicles' straight movements.

Crash Analysis of Lower Extremity Injuries in Children Restrained in Forward-facing Car Seats During Front and Rear Impacts

BACKGROUND

The mechanism, crash characteristics, and spectrum of lower extremity injuries in children restrained in forward-facing car seats during front and rear impacts have not been described.

METHODS

We identified in two databases children who sustained lower extremity injuries while restrained in forward-facing car seats. To identify the mechanism, we analyzed crash reconstructions from three frontal-impact cases from the Crash Injury Research and Engineering Network. To further describe the crash and injury characteristics we evaluated children between 1 and 4 years of age with lower extremity injuries from front or rear impacts in the National Automotive Sampling System (NASS) Crashworthiness Data System (CDS) database.

RESULTS

Crash reconstruction data demonstrated that the likely mechanism of lower extremity injury was contact between the legs and the front seatbacks. In the CDS database, we identified 15 children with lower extremity injuries in a forward-facing child seat, usually (13 out of 15) placed in the rear seat, incurred in frontal impacts (11 out of 15). Several (5 out of 15) children were in unbelted or improperly secured forward-facing car seats. Injury Severity Scores varied widely (5-50).

CONCLUSIONS

Children in forward-facing car seats involved in severe front or rear crashes may incur a range of lower extremity injury from impact with the car interior component in front of them. Crash scene photography can provide useful information about anatomic sites at risk for injury and alert emergency department providers to possible subtle injury.

Birth weight and breast cancer risk

Exploring whether the positive association between birth weight and breast cancer risk differs by other breast cancer risk factors may help inform speculation about biological mechanism. In these data, high birth weight was associated with breast cancer risk in younger and in more educated women, but was not associated overall.

Cultural aspects related to the health of Andean women in Latin America: a key issue for progress toward the attainment of the Millennium Development Goals

International declarations have affirmed that health is a universal right. In order for people to exercise their right to health, their social and cultural contexts need to be acknowledged. However, due to a number of barriers encountered at different levels of society and geographically this right is not yet fully exercised by a considerable number of women in Latin America. During the last decade progress has been made in the development of public health policies and programs that integrate and recognize the differences in culture that should be considered when addressing indigenous women's health issues. However, a biomedical health model, which discounts cultural influences, prevails globally over a more integrated approach. This leads to a lack of access and use of quality reproductive health services and care among indigenous people and is one of several important factors contributing to high levels of maternal mortality and poor reproductive health among indigenous women. It is important to ensure that an intercultural approach is included in health policies, programs and services. An intercultural strategy fosters dialogue and respect among women, men, and decision-makers and can contribute to the realization of reproductive health rights and improvement of health outcomes. The debate continues on how to accelerate progress in public policies, health programs and health services. An intercultural approach to assure the health of indigenous women should be a key part of this discussion. Specific efforts are critical for obtaining better health outcomes for indigenous women and other vulnerable populations, if not progress will stagnate in the middle of the 21st century, jeopardizing the attainment of the Millennium Development Goal (MDGs).

Melanin pattern morphs do not differ in metabolic rate: implications for the evolutionary maintenance of a melanophore polymorphism in the green swordtail, Xiphophorus helleri

Variation in melanin patterns among individuals, populations, and species is common in fishes of the genus Xiphophorus. In the variable platyfish, Xiphophorus variatus, variation in metabolic rate is associated with melanin coloration and the color morphs appear to be physiological specialists adapted to particular environmental conditions. This study investigates whether a melanin polymorphism in the green swordtail, Xiphophorus helleri, is likewise associated with variation in metabolic rate. We measured metabolic rate as oxygen consumption rate of both adult male and juvenile X. helleri in static respirometers. The oxygen consumption rate does not differ significantly between the spotted and nonspotted morphs in either group, suggesting that-unlike in X. variatus-selection on metabolic rate is not involved in maintaining the polymorphism in X. helleri. We suggest that explanations need to be sought for the evolution of melanophore diversity in Xiphophorus that are pertinent to each melanin pattern polymorphism or groups of similar polymorphisms.