A systematic review and meta-analysis of salivary cortisol measurement in domestic canines.

Salivary cortisol is widely used as an indicator of stress and welfare in canine research. However, much remains unclear about the basic features of this hormone marker in domestic dogs. This systematic review and meta-analysis aimed to determine a reference range for cortisol concentration in the saliva of dogs and examine how canine characteristics, environmental effects and experimental considerations relate to salivary cortisol concentrations. A systematic review of literature databases and conference proceedings from 1992 to 2012 identified 61 peer-reviewed studies using domestic dog salivary cortisol. Researchers were contacted via email, and 31 raw data sets representing a total of 5,153 samples from 1,205 dogs were shared. Meta-analysis provided a cortisol concentration range of 0 to 33.79 µg/dL (mean 0.45 µg/dL, SEM 0.13). Significant effects (P < 0.05) were found for sex and neuter status, age, regular living environment, time in environment before testing, testing environment, owner presence during testing, and collection media. Significant effects were not found for dog breed, body weight, dog type, coat color, assay type, exercise, eating, or use of salivary stimulant. Care should be taken when using cortisol studies for dogs at a group or population level as there is a large amount of intraindividual and interindividual variability and external variables could influence salivary cortisol concentration. This analysis highlights the importance of carefully controlling experimental design to compare samples within and between individual dogs, as well as establishing and using best practices for saliva collection. Caution should be exercised in comparing different studies, as the results could be the reflection of a plethora of factors.

An extremely compensatible cigarette by design: documentary evidence on industry awareness and reactions to the Barclay filter design cheating the tar testing system.

BACKGROUND: The Barclay cigarette (Brown & Williamson) was introduced in 1980 in the USA in the most expensive launch in history. In the USA and around the world, Barclay was later determined to have a grooved filter design that was compromised by human smokers in the normal act of smoking, but that was measured as ultra-low tar using the standard tar testing protocol. OBJECTIVES: To evaluate whether Brown & Williamson knew of the compensatability of Barclay during the design process and before it was released; to evaluate initial responses of competing tobacco companies to Barclay, before complaints were made to the Federal Trade Commission in 1981. METHODS: Internet databases of industry documents (Tobacco Documents Online, Legacy Tobacco Documents Library, Brown & Williamson Litigation discovery website, Guildford and major company websites) were searched using key words, key dates, and targeted searches. Documents related specifically to the development, evaluation and release of the Barclay cigarette and related to the responses by competing tobacco companies were examined. RESULTS: Documents indicate the manufacturer was aware of Barclay design problems and was planning, before release, to respond to criticism. Competing companies quickly detected the filter groove stratagem and considered developing their own similar filter, but eventually backed off. CONCLUSION: The design problems with Barclay were readily understood by cigarette manufacturers, including the maker of Barclay, before official governmental evaluations occurred. Testing involving measured exposures to human smokers may in the end be crucial to identifying problems with novel cigarette designs.

Developmental effects of early immune stress on aggressive, socially reactive, and inhibited behaviors.

The origins of individual differences in social development are examined in relation to early stress (immune challenge) and social milieu (maternal behavior) in a genetic-developmental analysis using an animal model. Neonatal male mice (5 or 6 days of age) from two lines of mice selectively bred for high versus low levels of inter-male aggressive behavior received a standard immune challenge (i.p. injections of 0.05 mg/kg endotoxin or saline). Animals were reared by their line-specific biological dam or by a foster dam from a line bred without selection. Adult levels of social behaviors were assessed in a dyadic test (age 45-50 days). Mice from the high-aggressive line show more developmental sensitivity to immune challenge than mice from the low-aggressive line, and line differences persist regardless of the early maternal environment. As adults, endotoxin-treated mice from the high-aggressive line have lower levels of aggressive behavior, longer latency to attack, and higher rates of socially reactive and inhibited behaviors compared to saline controls. Developmental effects of endotoxin in the low-aggressive line are minimal: endotoxin increases socially reactive behaviors, compared to saline controls, but only for mice reared by their biological dams. Rearing by foster dams increases social exploration in the low-aggressive line. The findings raise novel questions regarding the openness of behavioral systems to effects of nonobvious but omnipresent features of the environment, such as antigenic load, how these effects are integrated to affect social development and psychopathology, and the nature of intrinsic factors that contribute to individual differences in sensitivity to early stressors.