Pesticide assessment: Protecting public health on the home turf

Pesticide regulation is examined in the context of Health Canada’s Pest Management Regulatory Agency’s assessment of the chlorophenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) for turf. 2,4-D is the most common herbicide used to kill weeds in grass.The medical literature does not uniformly indicate harms from herbicides. However, the balance of epidemiological research suggests that 2,4-D can be persuasively linked to cancers, neurological impairment and reproductive problems. These may arise from 2,4-D itself, from breakdown products or dioxin contamination, or from a combination of chemicals.Regulators rely largely on toxicology, but experiments may not replicate exposures from 2,4-D application to lawns because environmental breakdown products (eg, 2,4-dichlorophenol) may not accumulate and selected herbicides are possibly less contaminated. Dioxins are bioaccumulative chemicals that may cause cancer, harm neurological development, impair reproduction, disrupt the endocrine system and alter immune function. No dioxin analyses were submitted to the Pest Management Regulatory Agency, and the principal contaminants of 2,4-D are not among the 17 congeners covered in pesticide regulation. Independent assessment of all dioxins is needed, in tissues and in the environment.The 2,4-D assessment does not approach standards for ethics, rigour or transparency in medical research. Canada needs a stronger regulator for pesticides. Potentially toxic chemicals should not be registered when more benign solutions exist, risks are not clearly quantifiable or potential risks outweigh benefits. Until landscaping pesticides are curtailed nationally, local bylaws and Quebec’s Pesticide Code are prudent measures to protect public health. Physicians have a role in public education regarding pesticides.     

Test-retest reliability of audio-taped phallometric stimuli with adolescent sexual offenders

Twenty adolescent male sexual offenders were evaluated by penile plethysmography on two separate occasions. Stimuli consisted of 19, two-minute audiotaped cues. Test-retest reliability was demonstrated for 15 of the 19 audiotaped vignettes. The highest correlations were found for those sexual behaviors in which the adolescents had engaged.     

The effect of central corneal thickness on estimates of the anterior chamber depth

Background: The slitlamp can be used to estimate the anterior chamber depth (ACD). The length of a slit object is increased until the corneal and iris/lens images appear to just touch. Multiplying the just‐touching‐slit‐length (JTSL) by a conversion factor gives an estimate of the ACD as measured by ultrasonography. The purpose of this study was to determine if central corneal thickness (CCT) affects the accuracy of this technique. Methods: The ACD of 50 subjects was measured by A‐scan ultrasonography and estimated by the slitlamp technique. CCT was measured by ultrasonic pachometry. The refractive error was determined subjectively. Results: The average ultrasonographic ACD for all subjects was 3.32 ± 0.65 mm. The average JTSL was 2.46 ± 0.38 mm. The conversion ratio between the ultrasonographic ACD and the average JTSL was 1.35. The predicted ACD using the regression equation of JTSL on the ultrasound anterior chamber depth (USACD) was 3.32 ± 0.54 mm. The corresponding value using the regression equation of JTSL and CCT on USACD was exactly the same, that is, 3.32 ± 0.54 mm. Conclusion: Incorporation of CCT into a regression equation does not improve the accuracy of the Smith technique.     

Brief report: child-rearing practices of caregivers with and without a child with juvenile rheumatoid arthritis: perspectives of caregivers and professionals

OBJECTIVE: To evaluate predictions from professionals in pediatric rheumatology regarding the child-rearing practices of caregivers of children with juvenile rheumatoid arthritis (JRA) and healthy classmates. METHODS: Sixteen professionals identified items from the Child-Rearing Practices Report (CRPR) that were expected to differentiate between caregivers of children with JRA (64 mothers, 45 fathers) and caregivers of healthy classmates (64 mothers, 40 fathers). Families were interviewed, and physician ratings of disease severity were obtained. RESULTS: Experts predicted difficulties in protectiveness, discipline, and worry. Ratings from parents of children with JRA showed modest agreement with the professionals, surprising similarity to controls, and a limited association with disease factors. CONCLUSIONS: Contrary to expert opinion, JRA has only a modest influence on some child-rearing practices. Educating health care providers may minimize misperceptions about caring for children with JRA, and screening parents of children with more severe disease may assist in allocating education and services for families.     

Competency-based evaluation tools for integrative medicine training in family medicine residency: a pilot study

Background  

As more integrative medicine educational content is integrated into conventional family medicine teaching, the need for effective evaluation strategies grows. Through the Integrative Family Medicine program, a six site pilot program of a four year residency training model combining integrative medicine and family medicine training, we have developed and tested a set of competency-based evaluation tools to assess residents' skills in integrative medicine history-taking and treatment planning. This paper presents the results from the implementation of direct observation and treatment plan evaluation tools, as well as the results of two Objective Structured Clinical Examinations (OSCEs) developed for the program.     

The history of contraction of the wrist flexors can change cortical excitability

Many freshwater turtles in temperate climates may experience winter periods trapped under ice unable to breathe, in anoxic mud, or in water depleted of O₂. To survive, these animals must not only retain function while anoxic, but they must do so for extended periods of time. Two general physiological adaptive responses appear to underlie this capacity for long-term survival. The first is a coordinated depression of metabolic processes within the cells, both the glycolytic pathway that produces ATP and the cellular processes, such as ion pumping, that consume ATP. As a result, both the rate of substrate depletion and the rate of lactic acid production are slowed greatly. The second is an exploitation of the extensive buffering capacity of the turtle's shell and skeleton to neutralize the large amount of lactic acid that eventually accumulates. Two separate shell mechanisms are involved: release of carbonate buffers from the shell and uptake of lactic acid into the shell where it is buffered and sequestered. Together, the metabolic and buffering mechanisms permit animals to survive for 3–4 months at 3 °C with no O₂ and with circulating lactate levels of 150 mmol l⁻¹ or more.