Metabolic consequences of chronic sleep restriction in rats:Changes in body weight regulation and energy expenditure

Epidemiological studies have shown an association between short or disrupted sleep and an increased risk to develop obesity. In animal studies, however, sleep restriction leads to an attenuation of weight gain that cannot be explained by changes in energy intake. In the present study, we assessed whether the attenuated weight gain under conditions of restricted sleep is a consequence of an overall increase in energy expenditure. Adult male rats were subjected to a schedule of chronic sleep restriction (SR) for 8 days with a 4 h window of unrestricted rest per day. Electroencephalogram and electromyogram recordings were performed to quantify the effect of the sleep restriction schedule on sleep-wake patterns. In a separate experiment, we measured sleep restriction-induced changes in body weight, food intake, and regulatory hormones such as glucose, insulin, leptin and corticosterone. To investigate whether a change in energy expenditure underlies the attenuation of weight gain, energy expenditure was measured by the doubly labeled water method from day 5 until day 8 of the SR protocol. Results show a clear attenuation of weight gain during sleep restriction but no change in food intake. Baseline plasma glucose, insulin and leptin levels are decreased after sleep restriction which presumably reflects the nutritional status of the rats. The daily energy expenditure during SR was significantly increased compared to control rats. Together, we conclude that the attenuation of body weight gain in sleep restricted rats is explained by an overall increase in energy expenditure together with an unaltered energy intake. Published by Elsevier Inc

Evidence for the existence of a new genus Chlamydiifrater gen. nov. inside the family Chlamydiaceae with two new species isolated from flamingo (Phoenicopterus roseus): Chlamydiifrater phoenicopteri sp. nov. and Chlamydiifrater volucris sp. nov.

The family Chlamydiaceae currently comprises a single genus Chlamydia, with 11 validly published species and seven more taxa. It includes the human pathogens Chlamydia (C.) trachomatis, C. pneumoniae and C. psittaci, a zoonotic agent causing avian chlamydiosis and human psittacosis, as well as other proven or potential pathogens in ruminants, birds, snakes, reptiles and turtles. During routine testing of 15 apparently healthy captive flamingos in a zoo in 2011, an atypical strain of Chlamydiaceae was detected by real-time PCR of cloacal swab samples. Sequence analysis of the 16S rRNA gene revealed high similarity to the uncultured Chlamydiales bacterium clone 122, which previously had been found in gulls. As more samples were collected during annual campaigns of the flamingo ringing program in southern France from 2012 to 2015, Chlamydiaceae-specific DNA was detected by PCR in 30.9% of wild birds. From these samples, three strains were successfully grown in cell culture. Ultrastructural analysis, comparison of 16S and 23S rRNA gene sequences, whole-genome analysis based on de novo hybrid-assembled sequences of the new strains as well as subsequent calculation of taxonomic parameters revealed that the relatedness of the flamingo isolates to established members of the family Chlamydiaceae was sufficiently distant to indicate that the three strains belong to two distinct species within a new genus. Based on these data, we propose the introduction of Chlamydiifrater gen. nov., as a new genus, and Chlamydiifrater phoenicopteri sp. nov. and Chlamydiifrater volucris sp. nov., as two new species of the genus.Martin Hölzer appreciates the support of the Joachim Herz Foundation by the add-on fellowship for interdisciplinary life science.Peer reviewe

Deliberate termination of life of newborns with spina bifida, a critical reappraisal

Objects: Deliberate termination of life of newborns (involuntary euthanasia) with meningomyelocele (MMC) is practiced openly only in the Netherlands. 'Unbearable and hopeless suffering' is the single most cited criterion for this termination, together with the notion that 'there are no other proper medical means to alleviate this suffering'. In this paper, both (and other) statements are questioned, also by putting them in a broader perspective. Methods: First, a historical overview of the treatment of newborns with MMC is presented, concentrating on the question of selection for treatment. Second, a thorough analysis is made of the criteria used for life termination. Third, a case of a newborn with a very severe MMC is presented as a 'reference case'. Conclusion: 'Unbearable and hopeless suffering' cannot be applied to newborns with MMC. They are not 'terminally ill' and do have 'prospects of a future'. In these end-of-life decisions, 'quality of life judgments' should not be applied. When such a newborn is not treated, modern palliative care always will suffice in eliminating possible discomfort. There is no reason whatsoever for active life-termination of these newborns

Circadian Time-Place Learning in Mice Depends on Cry Genes

Endogenous biological clocks allow organisms to anticipate daily environmental cycles. The ability to achieve time-place associations is key to the survival and reproductive success of animals. The ability to link the location of a stimulus (usually food) with time of day has been coined time-place learning, but its circadian nature was only shown in honeybees and birds. So far, an unambiguous circadian time-place-learning paradigm for mammals is lacking. We studied whether expression of the clock gene Cryptochrome (Cry), crucial for circadian timing, is a prerequisite for time-place learning. Time-place learning in mice was achieved by developing a novel paradigm in which food reward at specific times of day was counterbalanced by the penalty of receiving a mild footshock. Mice lacking the core clock genes Cry1 and Cry2 (Cry double knockout mice; Cry1-/-Cry2-/-) learned to avoid unpleasant sensory experiences (mild footshock) and could locate a food reward in a spatial learning task (place preference). These mice failed, however, to learn time-place associations. This specific learning and memory deficit shows that a Cry-gene dependent circadian timing system underlies the utilization of time of day information. These results reveal a new functional role of the mammalian circadian timing system.