Rural participants raised in the presence of farm animals show less immune activation following acute psychosocial stress

Urbanization is on the rise, although the urban environment is linked to an increased prevalence of both physical and mental disorders. Human and animal studies suggest that an over-reactive immune system not only accompanies stress-associated disorders, but might even be causally involved in their pathogenesis. Here we show in young (mean age, years, (SD): rural, 25.1 (0.78); urban, 24.5 (0.88)) healthy human volunteers that urban upbringing in the absence of pets (n=20), relative to rural upbringing in the presence of farm animals (n=20), was associated with an exaggerated systemic immune activation following psychosocial stress. Questionnaires, plasma cortisol, and salivary alpha-amylase, however, indicated that the experimental protocol was more stressful and anxiogenic for rural participants. In detail, in response to the Trier Social Stress Test (TSST), participants with an urban versus rural upbringing showed a more pronounced increase in the number of peripheral blood mononuclear cells (PBMCs) and plasma interleukin (IL)-6 concentrations. Moreover, ex vivo cultured PBMCs from urban versus rural participants secreted more IL-6 in response to the T cell-specific mitogen concanavalin A (ConA). In turn, anti-inflammatory IL-10 secretion was suppressed following TSST in urban versus rural participants, suggesting immunoregulatory deficits in urban participants following social stress. Together, our findings support the hypothesis that urban upbringing in the absence of pets, in contrast to rural upbringing in the presence of farm animals, increases the vulnerability for stress-associated physical and mental disorders by compromising adequate resolution of systemic immune activation following social stress and, in turn, aggravating stress-associated systemic immune activation

Association of the Salivary Microbiome With Animal Contact During Early Life and Stress-Induced Immune Activation in Healthy Participants

The prevalence of stress-associated somatic and psychiatric disorders is increased in environments offering a narrow relative to a wide range of microbial exposure. Moreover, different animal and human studies suggest that an overreactive immune system not only accompanies stress-associated disorders, but might even be causally involved in their pathogenesis. In support of this hypothesis, we recently showed that urban upbringing in the absence of daily contact with pets, compared to rural upbringing in the presence of daily contact with farm animals, is associated with a more pronounced immune activation following acute psychosocial stressor exposure induced by the Trier Social Stress Test (TSST). Here we employed 16S rRNA gene sequencing to test whether this difference in TSST-induced immune activation between urban upbringing in the absence of daily contact with pets (n = 20) compared with rural upbringing in the presence of daily contact with farm animals (n = 20) is associated with differences in the composition of the salivary microbiome. Although we did not detect any differences in alpha or beta diversity measures of the salivary microbiome between the two experimental groups, statistical analysis revealed that the salivary microbial beta diversity was significantly higher in participants with absolutely no animal contact (n = 5, urban participants) until the age of 15 compared to all other participants (n = 35) reporting either daily contact with farm animals (n = 20, rural participants) or occasional pet contact (n = 15, urban participants). Interestingly, when comparing these urban participants with absolutely no pet contact to the remaining urban participants with occasional pet contact, the former also displayed a significantly higher immune, but not hypothalamic-pituitary-adrenal (HPA) axis or sympathetic nervous system (SNS) activation, following TSST exposure. In summary, we conclude that only urban upbringing with absolutely no animal contact had long-lasting effects on the composition of the salivary microbiome and potentiates the negative consequences of urban upbringing on stress-induced immune activation.</p

Biomechanical comparison of different fixation methods in metatarsal shaft fractures: A cadaver study

Background: Various fixation methods are available for the operative treatment of metatarsal shaft fractures: Kirschner wire, Titanium elastic nail, plate, or an intramedullary bone stabilization system within a balloon catheter. The aim of this study was to compare the stability of these techniques. Methods: 72 metatarsals II to V from fresh frozen human cadaver feet were used. A shaft fracture was performed and fixed with a 1.6-mm Kirschner wire, a 1.5-mm Titanium elastic nail, a locking 6-hole-plate, or an intramedullary bone stabilization system. In a cantilever configuration, the head of the metatarsals was loaded statically (2 mm/min until failure; all groups) or cyclically (0 to 20 N for 1000 cycles with 10 mm/s, after 1000 cycles 2 mm/min until failure; plate and bone stabilization system). Findings: The mean failure strength for static loading was 17 N for Kirschner wire, 13 N for Titanium elastic nail, 73 N for plate and 34 N for the bone stabilization system (P < .01). For cyclic loading, the mean cycle of failure was 1000 for plate and 961 for the bone stabilization system (P = .76). The mean failure strength after cyclic loading was 73 N for plate and 48 N for the bone stabilization system (P = .03). Interpretation: Stability differs depending on the fixation method, with a plate showing the greatest stability and Kirschner wire or Titanium elastic nail the least. The stability of the bone stabilization system for fixing metatarsal shaft fractures is intermediate

Detection of a Toxic Methylated Derivative of Phomopsin A Produced by the Legume-Infesting Fungus <i>Diaporthe toxica</i>

Phomopsin A (PHO-A), produced by the fungus <i>Diaporthe toxica</i>, is a mycotoxin known to be responsible for fatal liver disease of lupin-fed sheep. The full spectrum of the toxic secondary metabolites produced by <i>D. toxica</i> is still unknown. PHO-A and the naturally occurring derivatives B–E have been subject to several studies to reveal their structures as well as chemical and toxicological properties. In this work, a methylated derivative (<b>1</b>) of PHO-A isolated from lupin seeds inoculated with <i>D. toxica</i> is described. It was characterized by high-resolution mass and NMR data and shown to be the <i>N</i>-methylated derivative of PHO-A. <b>1</b> is cytotoxic against HepG2 cells

Association of the Salivary Microbiome With Animal Contact During Early Life and Stress-Induced Immune Activation in Healthy Participants

The prevalence of stress-associated somatic and psychiatric disorders is increased in environments offering a narrow relative to a wide range of microbial exposure. Moreover, different animal and human studies suggest that an overreactive immune system not only accompanies stress-associated disorders, but might even be causally involved in their pathogenesis. In support of this hypothesis, we recently showed that urban upbringing in the absence of daily contact with pets, compared to rural upbringing in the presence of daily contact with farm animals, is associated with a more pronounced immune activation following acute psychosocial stressor exposure induced by the Trier Social Stress Test (TSST). Here we employed 16S rRNA gene sequencing to test whether this difference in TSST-induced immune activation between urban upbringing in the absence of daily contact with pets (n = 20) compared with rural upbringing in the presence of daily contact with farm animals (n = 20) is associated with differences in the composition of the salivary microbiome. Although we did not detect any differences in alpha or beta diversity measures of the salivary microbiome between the two experimental groups, statistical analysis revealed that the salivary microbial beta diversity was significantly higher in participants with absolutely no animal contact (n = 5, urban participants) until the age of 15 compared to all other participants (n = 35) reporting either daily contact with farm animals (n = 20, rural participants) or occasional pet contact (n = 15, urban participants). Interestingly, when comparing these urban participants with absolutely no pet contact to the remaining urban participants with occasional pet contact, the former also displayed a significantly higher immune, but not hypothalamic-pituitary-adrenal (HPA) axis or sympathetic nervous system (SNS) activation, following TSST exposure. In summary, we conclude that only urban upbringing with absolutely no animal contact had long-lasting effects on the composition of the salivary microbiome and potentiates the negative consequences of urban upbringing on stress-induced immune activation

Volunteering and Income - The Fallacy of the Good Samaritan?

This paper explores individual motives for volunteering. The analysis is based on the interpretation of volunteering as a consumption good (consumption model) or as a mean to increase individual's own human capital (investment model). We present an econometric framework taking into account self selection into volunteering and simultaneity between the volunteering decision and the determination of income in order to test these two models and to identify the underlying motives. Copyright 2007 Blackwell Publishing Ltd..