Cutting stress off at the pass: Reducing vigilance and responsiveness to social threat by manipulating attention.

Personality processes relating to social perception have been shown to play a significant role in the experience of stress. In 5 studies, the authors demonstrate that early stage attentional processes influence the perception of social threat and modify the human stress response. The authors first show that cortisol release in response to a stressful situation correlates with selective attention toward social threat. Second, the authors show in 2 laboratory studies that this attentional pattern, most evident among individuals with low self-esteem, can be modified with a repetitive training task. Next, in a field study, students trained to modify their attentional pattern to reduce vigilance for social threat showed lower self-reported stress related to their final exam. In a final field study with telemarketers, the attentional training task led to increased self-esteem, decreased cortisol and perceived stress responses, higher confidence, and greater work performance. Taken together, these results demonstrate the impact of antecedent-focused strategies on the late-stage consequences of social stress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Obesity: Prevalence,Theories, Medical Consequences,Management, and Research Directions

Obesity and its associated disorders are a growing epidemic across the world. Many genetic, physiological, and behavioral factors play a role in the etiology of obesity. Diet and exercise are known to play a valuable role in the treatment and prevention of obesity and associated disorders such as hypertension, heart disease, and diabetes. Therefore, the purpose of this review is to examine the prevalence, etiology, consequences, and treatment of obesity.     

Biological and psychological responses to two rapid shiftwork schedules

This study presents the biological responses to shiftwork in two groups of workers with different shiftwork rotas. Biological responses were studied by recording the heart rate and the changes in the circadian profile of salivary cortisol over 24?h (RIA assays). Various items were recorded through questionnaires aimed at determining self appreciation of sleep quantity, stress, health, satisfaction at work and in private lives. Thirty two male subjects aged from 23 to 56, working for the same company, having given their informed consent, took part in the study. The study was carried out under realistic conditions (at the work place) under the control of an occupational physician. Sixteen day-workers (8 am?–?6?pm) served as a reference group. Eight shiftworkers included in alternate schedules (morning M 4 am?–?12 am, evening E 12 am?–?8?pm, night N 8?pm?–?4 am) according to a system M, S, N 3/2, (3 work, 2 rest) and eight according to a system 7/5 (3M/2S/2N/5R, 2/3/2/5, 2/2/3/5) constituted the groups of shiftworkers respectively named 3/2 and 7/5. All subjects had comparable ages and BMIs. Shiftworkers expressed a higher stress level and frequency of health problems and a lower satisfaction at work than the control. Among the three groups, the 7/5 group had the best health and fitness score and was in need of less sleep. Heart rate was not affected by shift work. Conversely, consistent changes appeared in cortisol circadian profiles, the greatest changes appearing for the night shift and among the two groups of shiftworkers, more particularly for the 7/5 group. These changes correlated with self-perceived constraints of work and showed the difficulties of adaptation to shiftwork.     

Heat stress affects the expression of key genes in the placenta,placental characteristics,and efficiency of Saanen goats and the survival and growth of their kids

Heat stress is detrimental during gestation; however, the effects of heat stress on goat placental characteristics and kid survival remain unclear. The objective of this study was to evaluate the effects of heat stress at final gestation on cortisol concentration, placenta characteristics, and the expression of genes related to placenta. Forty-six primiparous and multiparous Saanen goats were subjected to control (CT; under a thermoneutral environment: air temperature between 12°C and 25°C and the relative humidity from 45 to 73%, n = 23) or heat stress (HS; under a climatic chamber: air temperature at 37°C and the relative humidity at 60 to 70% from 0800 to 1600 h, n = 23) from the last 60 d of pregnancy until the first colostrum suckling. The heat challenge imposed on HS goats during the prepartum period increased their rectal temperature, respiratory frequency, and cortisol levels in plasma and amniotic fluid versus CT goats. In the placenta, HS treatment also increased the expression of the HSPA1A gene. Heat-stressed goats also showed significantly lower expression of HSD11B2 and greater expression of MC2R and NR3C1 than CT goats, suggesting that heat stress decreased the effectiveness by which the HSD11B2 enzyme converts cortisol to cortisone and increased placental responsiveness to cortisol. The HS goats took longer to release the placenta with lighter placental cotyledons, and HS goats had a lower ratio between the kid's weight at birth and placenta weight than CT goats. There was no treatment effect on the kids' survival or weights at birth, but the kids from goats subjected to HS presented lesser cortisol concentration and greater mortality rates at weaning than kids from CT goats. Finally, the overexpression of HSPA1A by HS goats suggests a protective response of placenta. However, the heat stress negatively affected the placenta's expulsion length, placental cotyledons number, weight and area, the ratio between kid's weight and placenta weight, and cortisol signaling. Indeed, the upregulation of MC2R and NR3C1 and downregulation of HSD11B2 on placenta caused by heat stress were associated with greater cortisol concentrations in the amniotic fluid of HS goats. Although HS and CT kids had adequate weights and survival rate during the first weeks of life, the heat stress increased the mortality at weaning of HS kids versus CT kids, suggesting that the heat stress effect persists and can change the ability of kids to respond to weaning challenge.     

Virtual fencing technology to intensively graze lactating dairy cattle. II: Effects on cow welfare and behavior

Virtual fencing technology uses a neckband-mounted device to deliver an audio cue when an animal nears a virtual boundary that is set via a global positioning system, followed by an electrical stimulus if it crosses the boundary. The flexibility offered by this technology could revolutionize grazing management on dairy farms, but its application and effects on lactating dairy cattle have not been assessed. This experiment reports on the effects of an electric or a virtual front-fence on dairy cow behavior and welfare. Two temporally separated treatments were applied to a herd of 30 multiparous cows. Cows were provided an estimated 14 to 15 kg of dry matter/cow of fresh pasture in a new paddock every 24 h. From d 1 to 10 cows were grazed using a conventional electric front-fence (control treatment) and from d 14 to 23 they were grazed using a virtual front-fence (eShepherd, Agersens Pty Ltd.). Cows were trained to the technology from d 11 to 13. The milk production and live weight of individual cows were recorded daily. Cortisol concentrations were obtained from milk samples collected from individual cows on 3 d during each of the control and the virtual fence grazing periods, plus the first day of training. From d 6 of the experiment, 6 focal cows were fitted with a RumiWatch (Itin + Hoch GmbH) noseband sensor to monitor grazing and ruminating time, and 8 focal cows were fitted with an IceTag (IceRobotics Ltd.) sensors to monitor activity. Milk production, live weight, and the time cows spent standing and lying did not differ between the electric and virtual fence periods. Milk cortisol concentrations, activity, and the times spent ruminating and grazing were comparable between the electric and early virtual fence periods (i.e., d 1–3 with a virtual fence). However, at d 4 to 6 with a virtual fence, activity (steps taken and motion index) and time spent grazing were lower, and time spent ruminating was greater, compared with an electric fence. Further, least significant difference tests suggest milk cortisol concentrations were higher at d 5 with a virtual fence than at d 8 with an electric fence and d 1 with a virtual fence. We conclude there is no evidence of behavioral and welfare effects of virtual fencing on dairy cows in the days immediately following implementation of the technology in a simple intensive grazing regimen, but a longer study is required to fully elucidate effects beyond this period.     

牛肉、牛奶中可的松和氢化可的松含量分析

采用液相色谱-串联质谱技术分析我国部分地区市售牛肉、牛奶中可的松和氢化可的松的含量水平。均质的牛肉或牛奶样品在乙酸-乙酸钠缓冲液中酶解后用甲醇提取，提取液用石墨化碳黑固相萃取小柱和氨基固相萃取小柱净化，洗脱液氮吹至干并用甲醇溶液定容，液相色谱-串联质谱测定。采用SPSS?21.0软件进行数据分析。对采自我国9?省市的346?份牛肉和牛奶样品进行检测，分析牛肉和牛奶中可的松和氢化可的松的存在水平。牛肉和牛奶中均检出可的松和氢化可的松，检出率在86.1%～100.0%之间，检出含量范围为0.02～74.88?μg/kg。牛肉中可的松和氢化可的松的含量平均值（中位数）分别为1.69（1.14）?μg/kg和12.16（8.14）?μg/kg，牛奶中可的松和氢化可的松的含量平均值（中位数）分别为0.23（0.23）?μg/kg和0.72（0.72）?μg/kg。牛肉和牛奶中氢化可的松与可的松的含量均呈显著正相关。     

Study of progesterone and cortisol concentrations in the Italian Friesian claw

The present research was conducted to study progesterone and cortisol concentrations in the claw of cattle and to verify whether the cattle claw could be considered an efficient matrix to provide retrospective information regarding progesterone and cortisol concentrations related to pregnancy and peripartum periods. These 2 steroids are involved in hoof growth. The study was performed on 32 calves and 24 pregnant milking cows of the Holstein breed, which were clinically healthy and lacking any claw disorders. Samples of at least 0.5 cm in thickness were taken from the sole. Progesterone and cortisol concentrations were determined by RIA. The cortisol concentration in the horny shoe of calves from 0 to 30 d of age was significantly higher than the concentration at 31 to 60 and 61 to 120 d of age. Conversely, the progesterone concentration showed no statistically significant difference in relation to age. The horn progesterone concentrations recorded in the milking dairy cows at 7 mo of pregnancy showed high variability in the horizontal sections of the sole (the individual coefficient of variation ranged between 0.09 and 1.11). In 6 cows, genuine extreme values (genuine outliers) of the progesterone level were found. Moreover, significant differences existed among the progesterone concentrations of the sole's transverse sections. We detected a significant positive correlation between the weight of the horn samples after freeze-drying and their weight after hydration. The cortisol and progesterone levels in soaked horn samples were found to be significantly lower than in the same dry samples. These results show that cortisol and progesterone can be measured in the cattle claw horn. The claws of mature dairy cows could not be used as a matrix to provide a retrospective measure of cumulative hormone secretion, whereas the analysis of the calves’ claw horns showed retrospective hormonal information similar to hair samples.     

Salivary cortisol and cardiovascular reactivity to a public speaking task in a virtual and real-life environment

Public speaking is a well-known psychosocial stress to occur in social-evaluative situations. This study examined self-reported, autonomic and endocrine stress responses to a 5-min public speaking task. Participants were asked to present either in front of i) a real audience, or ii) a virtual audience or iii) an empty virtual lecture hall. Thus, the main objective of this study was to examine the influence of real or virtual social stimuli on stress reactivity. Additionally, possible sex differences in stress responses were evaluated. Sixty-six women and men (20–33 years) underwent a multidimensional assessment of stress including self-reported state anxiety, heart rate, heart rate variability and saliva cortisol secretion. Results showed comparable increases in all stress responses in both the real and the virtual public speaking group. These findings indicate that the Self Preservation Theory is not limited to physically present social entities, but may also be extended to virtual social stimuli; as such this observation is also in line with the so called Media Equation Concept. Implications of the current results for therapy and research are subsequently discussed.     

The Association of Cholesterol Uptake and Synthesis with Histology and Genotype in Cortisol-Producing Adenoma (CPA)

Cortisol-producing adenoma (CPA) is composed of clear and compact cells. Clear cells are lipid abundant, and compact ones lipid poor but associated with higher production of steroid hormones. PRKACA mutation (PRKACA mt) in CPA patients was reported to be associated with more pronounced clinical manifestation of Cushing’s syndrome. In this study, we examined the association of histological features and genotypes with cholesterol uptake receptors and synthetic enzymes in 40 CPA cases, and with the quantitative results obtained by gas chromatography-mass spectrometry (GC-MS) analysis in 33 cases to explore their biological and clinical significance. Both cholesterol uptake receptors and synthetic enzymes were more abundant in compact cells. GC-MS analysis demonstrated that the percentage of compact cells was inversely correlated with the concentrations of cholesterol and cholesterol esters, and positively with the activity of cholesterol biosynthesis from cholesterol esters. In addition, hormone-sensitive lipase (HSL), which catalyzes cholesterol biosynthesis from cholesterol esters, tended to be more abundant in compact cells of PRKACA mt CPAs. These results demonstrated that both cholesterol uptake and biosynthesis were more pronounced in compact cells in CPA. In addition, more pronounced HSL expression in compact cells of PRKACA mt CPA could contribute to their more pronounced clinical manifestation.     

皮质醇激素和血液生化指标变化对猪肉劣质肉的指示作用

为寻找猪肉劣质肉的指示指标,比较了不同质量猪肉对应皮质醇激素和血液生化指标的变化。结果表明,劣质肉中白肌肉(PSE)对应生猪血糖浓度显著高于正常肉(RFN)(P<0.05),劣质肉中黑干肉(DFD)对应生猪皮质醇浓度显著高于RFN肉(P<0.05)。说明血糖可作为劣质肉中PSE肉的重要指示指标,当宰前血糖浓度达到(17.21±3.12)mol/L时,可能产PSE肉;皮质醇可作为劣质肉中DFD肉的重要指示指标,当宰前皮质醇浓度达到(512.70±49.9)nmol/L时,可能产生DFD肉。