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The oxytocinergic system is involved in a range of functions, from attachment and social bonding to aggression and stress responses. Whether oxytocin is released in response to a stressor, shows contradictory results across species and potential contexts-dependent differences. To avoid unintended contextual changes due to experimental procedures, we tested this question non-invasively in wild chimpanzees in an ecologically valid context. We collected endogenous hormonal measures during exposure to a known natural stressor, intergroup conflict. Specifically, we tested for potential synchronous activation patterns between urinary oxytocin and cortisol in male and female chimpanzees during stressor exposure. Oxytocinergic system reactivity during chimpanzee intergroup conflict has already been established in this study population. Thus, we first investigated urinary cortisol levels during border patrol and intergroup encounter days, in comparison to another potential stressor, hunting, and control days. We found higher urinary cortisol levels during intergroup encounter days compared with control and hunting days. We then compared secretion patterns of oxytocin and cortisol in relation to increased levels of out-group contact and hostility ('out-group risk') during intergroup conflict. We found that increased 'out-group risk' was associated with higher cortisol levels, especially when involving direct visual or physical contact with rival groups. Although urinary oxytocin levels were high across intergroup conflict contexts, increasing levels of out-group risk showed no significant variation. Taken together, results indicate independent secretion of oxytocin and cortisol during chimpanzee intergroup conflict, emphasizing that stressor exposure in this context is not the main trigger of oxytocin secretion., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Many animals living in social groups have evolved behaviors to resolve conflicts between group members, behaviors thought crucial for maintaining stable group life. Several hypotheses, based mainly on observational data, aim to explain how post-conflict (PC) affiliations, such as reconciliation and consolation, resolve conflicts by restoring relationships and/or alleviating anxiety. To examine a potential endocrinological mechanism of PC affiliations, we used an experimental-like procedure to investigate whether the oxytocinergic system is activated during naturally observed reconciliations, receiving bystander PC affiliations and aggressions not followed by PC affiliations in wild male chimpanzees. We compared urinary oxytocin (uOT) levels after reconciliations, receiving bystander PC affiliations or aggressions without affiliations with two control conditions: affiliations without previous aggression and after time periods without social interactions. We furthermore tested the 'valuable relationship' hypothesis of reconciliation, as well as the influence of relationship quality between individuals engaged in each of the three behavioral conditions involving aggression on uOT levels. We found that the probability to reconcile a conflict increased with increasing relationship quality between opponents, thus our results support the 'valuable relationship' hypothesis. However, relationship quality did not influence uOT levels, while behavioral condition had a significant effect on uOT levels. uOT levels after reconciliations, receiving bystander PC affiliations and affiliations not related to conflicts were higher than after aggressions alone and time periods without social interactions. Overall, our results indicate that the oxytocinergic system is activated during affiliative interactions, whether occurring as reconciliation, bystander PC affiliation or affiliation alone. We conclude that the oxytocinergic system, in addition to building and maintaining social relationships, also takes part in repairing them., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Treponema pallidum infections causing yaws disease and venereal syphilis are globally widespread in human populations, infecting hundreds of thousands and millions annually respectively; endemic syphilis is much less common, and pinta has not been observed in decades. We discuss controversy surrounding the origin, evolution and history of these pathogens in light of available molecular and anthropological evidence. These bacteria (or close relatives) seem to affect many wild African nonhuman primate (NHP) species, though to date only a single NHP Treponema pallidum genome has been published, hindering detection of spillover events and our understanding of potential wildlife reservoirs. Similarly, only ten genomes of Treponema pallidum infecting humans have been published, impeding a full understanding of their diversity and evolutionary history. Research efforts have been hampered by the difficulty of culturing and propagating Treponema pallidum. Here we highlight avenues of research recently opened by the coupling of hybridization capture and next-generation sequencing. We present data generated with such an approach suggesting that asymptomatic bones from NHP occasionally contain enough treponemal DNA to recover large fractions of their genomes. We expect that these methods, which naturally can be applied to modern biopsy samples and ancient human bones, will soon considerably improve our understanding of these enigmatic pathogens and lay rest to old yet unresolved controversies., (Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

The reasons for the well-known significantly different behaviour of the anaerobic, gram-negative, ethanologenic bacterium Zymomonas mobilis during growth on fructose (i.e. decreased growth and ethanol yields, increased by-product formation) as compared to that on its second natural substrate, glucose, have remained unexplained. A xylose-fermenting recombinant strain of Z. mobilis that was recently constructed in our laboratory also unexpectedly displayed an increased formation of by-products and a strongly reduced growth rate as compared to the parent strain. Therefore, a comprehensive study employing recently developed NMR-based methods for the in vivo analysis of intracellular phosphorylated pool sizes and metabolic fluxes was undertaken to enable a global characterization of the intracellular metabolic state of Z. mobilis during growth on 13C-labelled glucose, fructose and xylose in defined continuous cultures. The 13C-NMR flux analysis indicated that ribose 5-phosphate is synthesized via the nonoxidative pentose phosphate pathway in Z. mobilis, and it identified a metabolic bottleneck in the recombinant xylose-fermenting Z. mobilis strain at the level of heterologous xylulokinase. The 31P-NMR analyses revealed a global alteration of the levels of intracellular phosphorylated metabolites during growth on fructose as compared to that on glucose. The results suggest that this is primarily caused by an elevated concentration of intracellular fructose 6-phosphate.

To determine the association of HLA DR2 in patients with narcolepsy without cataplexy, a case-control study was performed. Patients receiving the diagnosis of narcolepsy without cataplexy had excessive daytime sleepiness (EDS) and polysomnographic findings consistent with narcolepsy but no clinical evidence of cataplexy. Of 28 patients identified, 12 agreed to return for HLA typing. Respondents did not differ from nonrespondents in demographic, clinical, or sleep laboratory data. The comparison group was 503 individuals, those 30 years and older, on the Michigan Kidney Transplant Registry. The odds ratio obtained from logistic regression indicated a strong association between narcolepsy without cataplexy and HLA DR2. To control for potential confounding variables, multivariate models were constructed to explore the joint effects of HLA DR2 and each one of the covariates (age, sex, and race), their possible combinations, and the effect of all three covariates. The odds ratios decreased minimally and the association between the disease and HLA DR2 remained significant.

In order to better characterize the subjective and polysomnographic findings in patients with narcolepsy, a follow-up questionnaire was mailed to all patients diagnosed with the disorder at the Henry Ford Hospital Sleep Disorders and Research Center. The questionnaire inquired regarding the present, previous, and change in status for the constellation of narcolepsy symptoms. Memory problems, problems of daytime function, and nocturnal sleep disturbance were included among the questions related to the symptomatic constellation. By definition, all patients were symptomatic of daytime sleepiness and were diagnosed with narcolepsy only if there were two or more rapid eye movement (REM) onsets documented on the polysomnographic evaluation. A high percentage of patients reported nocturnal sleep disturbance, which was one of the symptoms with the latest reported onset. Retrospective comparison of questionnaire responses to the clinical polysomnography revealed significantly more sleep maintenance difficulties in the group of patients reporting this symptom on the questionnaire. Patients with disturbed nocturnal sleep reported taking more naps during the day, although the Multiple Sleep Latency Test (MSLT) failed to show differences in sleep latency. Interestingly, this group of patients was found to have a significantly higher number of sleep onset REM episodes on the MSLT. Finally, the findings are discussed as they compare to studies that required the presence of cataplexy as part of their inclusion criteria.

A new surgical procedure to treat obstructive sleep apnea by uvulopalatopharyngoplasty (UPPP) was evaluated in 66 patients, 63 men and 3 women, with objectively documented sleep apnea syndrome. Removal of redundant tissue in the oropharynx (UPPP) significantly improved excessive daytime sleepiness, reduced by half the frequency of apneas and hypoxia occurring during sleep, and improved the quality of sleep. Closer analysis indicated that all 66 patients did not benefit to the same degree. Among patients classified as responders, the frequency of apnea was reduced to a level seen in healthy adults of the same age, measures of sleep approached normal, and excessive daytime sleepiness was eliminated. In nonresponders, frequency of apnea and consequent disruption of sleep was not reduced, but nocturnal hypoxia was improved.

The consistency of apneas from night to night was examined in 2 groups of patients. The first group had more than 100 apneas per night (frequent apnea) and the second group had less than 100 apneas per night (infrequent apnea). All patients underwent clinical polysomnography for 2 nights, with no significant weight change or treatment occurring between recordings. The frequent apnea group showed a consistent number of apneas on the 2 nights (r = 0.92, p less than 0.01), whereas the infrequent apnea group showed a highly variable number of apneas (r = 0.35, p greater than 0.10). The correlations on apnea index (apneas per hours of sleep) showed a similar result. Apnea duration and type were consistent in both groups of patients.

This study examined whether narcoleptics experience an age-related increase in nocturnal sleep disturbance and, if so, what impact that disturbance has on daytime sleepiness. To evaluate these questions, the records of 228 patients diagnosed as narcoleptic were assessed. Total sleep time (TST) and sleep efficiency (SE) significantly decreased, and wake during sleep (WDS), number of awakenings, and percentage of stage one significantly increased across the decades. This indicates an age-related elevation in sleep fragmentation. Daytime sleepiness, however, did not exhibit age effects. These data further support the theory that narcolepsy is a basic neural defect not confounded by excessive daytime sleepiness secondary to sleep fragmentation.

A polysomnographic assessment in healthy normal sleepers of possible dose relations for rebound insomnia was conducted. As an additional measure of rebound the study included a direct test of sleep/wake tendency during the night of drug discontinuation. Twelve, healthy men (21-30 years) each received placebo, 0.25 mg and 0.50 mg triazolam for 6 consecutive nights followed by a discontinuation night and 14 nights of recovery at home. The three conditions were presented, double-blind, in a latin square design. On night 6 of drug administration both doses increased total sleep time compared to placebo, but 0.50 mg did not improve sleep beyond 0.25 mg. On drug discontinuation (night 7) wake time over the 8 h recording and sleep latency after an experimental awakening (02.30 h) were increased with 0.50 mg compared to placebo and 0.25 mg. On these measures of rebound 0.25 mg did not differ from placebo. Thus rebound insomnia occurred only at a dose (0.50 mg) which produced no additional hypnotic efficacy in these normal sleepers. Whether tests of sleep/wake tendency make a useful measure of rebound insomnia needs further clarification.