Urinary corticosteroid excretion patterns in the okapi (Okapia johnstoni)

Stress is known to alter a variety of biological processes, including behavior and reproduction. It is therefore important to understand the stress levels of animals in captivity, especially those for whom captive breeding is a priority, such as the okapi. Levels of stress hormones can be measured from samples collected noninvasively, such as urine or feces, which are preferable with nondomestic species for whom drawing blood might in itself be a considerable stressor. To understand the excretion of cortisol in urine in the okapi, four (1.3) animals were subject to three injections: saline, 200 IU of an adrenocorticotropic hormone (ACTH) analogue, and 300 IU of the analogue. Their 24‐hr urinary corticosteroid levels were compared with 4 baseline days. Injection with the ACTH analogue significantly increased the urinary corticosteroid levels compared with saline injections and baseline. Eight (3.5) okapi were then observed for 24 hr per day for 5 days to determine their normal patterns of corticosteroid production. The mean corticosteroid levels varied significantly by individual. A significant circadian pattern in urinary corticosteroid was apparent independent of individual or gender, with cortisol rising during the daylight hours and decreasing again at night. Zoo Biol 27:381–393, 2008. © 2008 Wiley‐Liss, Inc.     

Menstrual hut visits by Dogon women: a hormonal test distinguishes deceit from honest signaling

In humans the interests of males and females may conflict withrespect to the attribution of paternity. If a female has conceivedthrough adultery, or changes mates while she is in early pregnancy,she may protect her reproductive investment by misassigningpaternity. In Mali, West Africa, Dogon males attempt to preventfemale deception by mandating honest advertisement of menstruation(Strassmann, 1992). This advertisement takes place at a menstrualhut where women are on display to all the members of their husband'slineage. Knowledge of the timing of menstruation is pivotalbecause no other physiological event is as useful in paternityassessments. In this article I use hormonal data and a censusof menstrual hut visits to quantify female compliance with themenstrual taboos. The sample includes 93 women who providedurine samples twice weekly for 10 weeks. Analysis of urinarysteroid hormone metabolites (pregnanediol-3-glucuronide andestrone-3-glucuronide) demonstrates that the women went to themenstrual huts during 86% of all menses and, with the exceptionof one woman who may have been spotting, they never went tothe menstrual huts during pregnancy or amenorrhea. Thus themenstrual taboos of the Dogon were effective in eliciting honestsignals of female reproductive status (pregnant, amenorrheic,or cycling). This study is the first to use hormonal data totest the honesty of a human behavior in a nonlaboratory setting.It also establishes the feasibility of urinary enzyme immunoassaysas a tool for studying human reproduction in remote populations.[Behav Ecol 7: 304-315 (1996)]     

Rapid determination of Proteus mirabilis susceptibility to antibiotics using infrared spectroscopy in tandem with random forest

Bacterial infections cause serious illnesses that are treated with antibiotics. Currently used methods for detecting bacterial antibiotic susceptibility consume 48–72 h, leading to overuse of antibiotics. Thus, many bacterial species have acquired resistance to a broad range of available antibiotics. There is an urgent need to develop efficient methods for rapid determination of bacterial susceptibility to antibiotics. The combination of machine learning and Fourier-transform infrared (FTIR) spectroscopy has generated a promising diagnostic approach in medicine and biology. Our main goal is to examine the potential of FTIR spectroscopy to determine the susceptibility of urinary tract infection-Proteus mirabilis to a specific range of antibiotics, within about 20 min after 24 h culture and identification. We measured the infrared spectra of 489 different P. mirabilis isolates and used random forest to analyze this spectral database. A classification success rate of ~84% was achieved in differentiating between the resistant and sensitive isolates based on their susceptibility to ceftazidime, ceftriaxone, cefuroxime, cefuroxime axetil, cephalexin, ciprofloxacin, gentamicin, and sulfamethoxazole antibiotics in a time span of 24 h instead of 48 h.     

A temperature-dependent structural change of mitochondrial ATPase

The temperature dependence of the intrinsic tryptophan fluorescence in either bovine heart submitochondrial particles or oligomycin-sensitive ATPase isolated therefrom shows a discontinuity at near 25°C, which coincides with the temperature where a break in the Arrhenius plot of ATPase activity is found. Addition of n-butanol to submitochondrial particles induces a decrease of tryptophan fluorescence in the whole temperature range. The discontinuity is interpreted as a temperature-dependent structural change and related to a viscosity-induced phase separation of the intrinsic mitochondrial proteins.     

Prespawning stress in farmed Atlantic salmon Salmo salar: maternal cortisol exposure and hyperthermia during embryonic development affect offspring survival, growth and incidence of malformations

In the current study, mature female Atlantic salmon Salmo salar were given intraperitoneal cortisol implants with the purpose of elucidating potentially detrimental effects on offspring survival, growth, morphological development and also the ability of prenatally stressed offspring to cope with an environmental stressor, typified by a period of mild hyperthermia. Augmented levels of maternal cortisol inflicted a range of progeny somatic parameters, as reflected in increased mortality, reduced fork length and mass, diminished yolk-sac volume, decelerated yolk-sac utilization and, to some extent, enhanced prevalence of morphological malformations. The most pronounced consequences on offspring performance were demonstrated in specimens exposed to both enhanced prenatal cortisol and a subsequent episode of hyperthermia. This accentuates the importance of knowledge on how the maternal endocrinological state during gametogenesis may impinge on offspring characters in farmed Atlantic salmon, and further substantiates the necessity of incorporating maternal effects when evaluating rearing conditions and animal welfare in commercial aquaculture.     

Variations of Some Physiological and Immunological Parameters in Siberian Sturgeon (Acipenser baerii,Brandt, 1869) Subjected to an Acute Stressor

This study was carried out to investigate the effect of an acute stressor on the variation of some physiological and immunological parameters of Siberian sturgeon (Acipenser baerii) juveniles. Fish, reared in 3 tanks for 10 weeks, were used for this study. The acute stress of fish consisted of 2 min of air exposure stress. Plasma levels of cortisol, glucose, and lactate as well as lysozyme activity in plasma were measured before stress and 1 hr, 3 hr, 6 hr, 9 hr, 12 hr, and 24 hr after stress. The plasma cortisol significantly increased in the highest level 1 hr after stress, yet it gradually declined after 3 hr. The glucose significantly increased only 1 hr after stress. There was no significant difference between plasma lactate prestress and poststress. Moreover, lysozyme activity was enhanced by stress, thus reaching the highest level 9 hr after stress. The results of this study indicate that Siberian sturgeon not only have a rapid response to acute stress, but also a great capacity for recovery from stress, thus returning physiological parameters to prestress levels after 6 hr.