Circadian Disruption: comparing humans with mice

Disruption of the 24-h light-dark cycle has been implicated as an endocrine disruptor and linked to increased morbidity and mortality in animal studies. Previously reported measurements of circadian disruption in day-shift and rotating-shift nurses were compared with new mouse data where the light-dark patterns simulated shiftwork. Phasor magnitudes, a measure of circadian entrainment, were shown to be similar for humans and for mice when exposed to similar patterns of light and dark. Phasor analyses may be a useful method for quantitatively bridging ecological measurements of circadian disruption in human with parametric studies of health outcomes in a mouse model.     

Rapid evolution of a young L1 (LINE-1) clade in recently speciated rattus taxa

L1 elements are retrotransposons that have been replicating and evolving in mammalian genomes since before the mammalian radiation. Rattus norvegicus shares the young L1_mlvi2 clade only with its sister taxon, Rattus cf moluccarius. Here we compared the L1_mlvi2 clade in these recently diverged species and found that it evolved rapidly into closely related but distinct clades: the L1_mlvi2-rm clade (or subfamily), characterized here from R. cf moluccarius, and the L1_mlvi2-rn clade, originally described in R. norvegicus. In addition to other differences, these clades are distinguished by a cluster of amino acid replacement substitutions in ORF I. Both rat species contain the L1_mlvi2-rm clade, but the L1_mlvi2-rn clade is restricted to R. norvegicus. Therefore, the L1_mlvi2-rm clade arose prior to the divergence of R. norvegicus and R. cf moluccarius, and the L1_mlvi2-rn clade amplified after their divergence. The total number of L1_mlvi2-rm elements in R. cf moluccarius is about the same as the sum of the L1_mlvi2-rm and L1_mlvi2-rn elements in R. norvegicus. The possibility that L1 amplification is in some way limited so that the two clades compete for replicative supremacy as well as the implications of the other distinguishing characteristic of the L1_mlvi2-rn and L1_mlvi2-rm clades are discussed. Received: 6 November 1996 / Accepted: 12 April 1997     

Use of a vaginal probiotic suppository and antibiotics to influence the composition of the endometrial microbiota

The aim of the present study was to determine the status of the endometrial microbiota in patients with repeated implantation failure (RIF) and to assess treatment strategies for nondominant Lactobacillus (NLD) cases. A total of 392 patients with RIF were enrolled in this prospective cohort study (UMIN-CTR 000038582) and underwent endometrial microbiota analysis. Patients diagnosed with NLD were treated with a combination of oral and vaginal probiotics or oral prebiotics and antibiotics. The outcome was evaluated through re-analysis of the endometrial microbiota following treatment, and the results are presented as cure rates. NLD represented 44.9 % of the total endometrial microbiota in patients with RIF. The most commonly detected bacterium was Gardnerella vaginalis. The cure rates in the oral probiotics + oral prebiotics, antibiotics, oral probiotics + oral prebiotics + antibiotics, vaginal probiotic suppository, and vaginal probiotic suppository + antibiotics groups were 29.5, 33.33, 33.33, 43.6, and 78.6 %, respectively. Significant improvements were noted in the vaginal probiotic suppository + antibiotics group. Moreover, we revealed that approximately half of patients with RIF had NLD. Thus, the combination of a vaginal probiotic suppository and antibiotics may represent an effective treatment for NLD cases.     

Exocytosis from chromaffin cells: hydrostatic pressure slows vesicle fusion

Pressure affects reaction kinetics because chemical transitions involve changes in volume, and therefore pressure is a standard thermodynamic parameter to measure these volume changes. Many organisms live in environments at external pressures other than one atmosphere (0.1 MPa). Marine animals have adapted to live at depths of over 7000 m (at pressures over 70 MPa), and microorganisms living in trenches at over 110 MPa have been retrieved. Here, kinetic changes in secretion from chromaffin cells, measured as capacitance changes using the patch-clamp technique at pressures of up to 20 MPa are presented. It is known that these high pressures drastically slow down physiological functions. High hydrostatic pressure also affects the kinetics of ion channel gating and the amount of current carried by them, and it drastically slows down synaptic transmission. The results presented here indicate a similar change in volume (activation volume) of 390 ± 57 ų for large dense-core vesicles undergoing fusion in chromaffin cells and for degranulation of mast cells. It is significantly larger than activation volumes of voltage-gated ion channels in chromaffin cells. This information will be useful in finding possible protein conformational changes during the reactions involved in vesicle fusion and in testing possible molecular dynamic models of secretory processes.     

Analysis of Oxidative Stress in Zebrafish Embryos

High levels of reactive oxygen species (ROS) may cause a change of cellular redox state towards oxidative stress condition. This situation causes oxidation of molecules (lipid, DNA, protein) and leads to cell death. Oxidative stress also impacts the progression of several pathological conditions such as diabetes, retinopathies, neurodegeneration, and cancer. Thus, it is important to define tools to investigate oxidative stress conditions not only at the level of single cells but also in the context of whole organisms. Here, we consider the zebrafish embryo as a useful in vivo system to perform such studies and present a protocol to measure in vivo oxidative stress. Taking advantage of fluorescent ROS probes and zebrafish transgenic fluorescent lines, we develop two different methods to measure oxidative stress in vivo: i) a “whole embryo ROS-detection method” for qualitative measurement of oxidative stress and ii) a “single-cell ROS detection method” for quantitative measurements of oxidative stress. Herein, we demonstrate the efficacy of these procedures by increasing oxidative stress in tissues by oxidant agents and physiological or genetic methods. This protocol is amenable for forward genetic screens and it will help address cause-effect relationships of ROS in animal models of oxidative stress-related pathologies such as neurological disorders and cancer.     

Dissecting apple tree architecture into genetic, ontogenetic and environmental effects: QTL mapping

The present study aimed to dissect tree architectural plasticity into genetic, ontogenetic and environmental effects over the first 4 years of growth of an apple F1 progeny by means of quantitative traits loci (QTL) mapping. Both growth and branching processes were phenotyped on the consecutive annual shoots of different axes within a tree. For each studied trait, predicted values (best linear unbiased predictors, BLUPs) of the genotypic (G) effect or its interaction with tree age (G×A) and climatic year (G×Y) were extracted from mixed linear models of repeated data. These BLUPs, which are independent from autocorrelations between repeated measurements, were used for QTL mapping. QTL detection power was improved by this two-step approach. For each architectural process, numerous QTLs were detected and some particularly interesting co-localised in common genomic regions, for internode lengthening, top diameter, and number and percentage of axillary shoots. When several QTLs were detected for a given trait, global models were estimated, which explained a maximum of 40% of the total variance for both internode length and top diameter and 28% for branching. QTLs detected for BLUPs of G×Y effects were interpreted as resulting from the interaction between genetic maximal potential of growth and climatic factors, while those for G×A effects were interpreted in relation to tree ontogeny. Most of the latter ones were found to be concomitant with key development stages during which the trait average started to decrease, but with different magnitudes depending on genotype. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Fully automatic input function determination program for simple noninvasive 123I-IMP microsphere cerebral blood flow quantification method

We recently developed a simple noninvasive ¹²³I-IMP microsphere (SIMS) method using chest dynamic planar images and brain single photon emission computed tomography. The SIMS method is an automatic analysis method, except for the process of setting the region of interest (ROI) of the input function. If a fully automatic ROI setting algorithm can be developed to determine the input function for the SIMS method, repeatability and reproducibility of the analysis of regional cerebral blood flow (rCBF) of the SIMS method can be guaranteed. The purpose of this study is to develop a fully automatic input function determination program for the SIMS method and to confirm the clinical usefulness of this program.The automatic input function determination program consists of two ROI setting programs for the PA and lung regions, and it is developed using the image phase analysis of a chest RI angiogram. To confirm the clinical usefulness of this program, the rCBF in 34 patients measured using the automatic method were compared with the values obtained through the manual setting method.Input functions by the automatic and manual methods were approximately equal. A good correlation was observed between the rCBF values obtained by the automatic method and those obtained by the manual setting method (r = 0.96, p < 0.01).Further, the total time taken for the automatic SIMS analysis is 1–2 min as compared to 20–30 min for the current analysis, and therefore, this technique contributes to the improvement of the throughput of nuclear medical examinations.     

A fully implantable multi-channel biotelemetry system for measurement of blood flow and temperature: a first evaluation in the green sturgeon

The objective of this study was to evaluate a novel fully implantable radio-based blood flow biotelemetry system which allows simultaneously measurement of blood flow on two channels and temperature on one channel, in fish. These are the first recordings of blood flow from free-swimming fish, showing that the system is capable of recording blood flow in the ventral aorta (cardiac output) and celiacomesenteric artery (gastrointestinal blood flow) in green sturgeon Acipenser medirostris exposed to a series of different stimuli for up to 7 days after implantation. The results showed stable base line recordings and blood flow was used to calculated heart rate (f _H) and stroke volume (V _s). It was possible to reproduce the same type of responses as has previously been reported during exposure to hypoxia, temperature, stress and feeding. The mass of our implant was less than 2% of the body mass which is well within the recommended sizes for surgically implanted telemetry transmitters and it fitted easily within the abdominal cavity of the sturgeon. A fully implantable system minimizes the risk of infection/expulsion and maximizes the likelihood that the studied fish will behave naturally and be treated normally by surrounding fish. The use of biotelemetry in basic comparative physiology and applied animal ecology could help scientists to collect information that has previously been challenging to obtain and to open the possibility for new types of physiological and ecophysiological studies. Handling editor: K. Martens     

甲状腺自身免疫状态及细胞毒性对不孕妇女反复植入失败的影响

为了探讨RIF患者的甲状腺功能、自身免疫状态、免疫细胞及其相关性,从72名RIF妇女中抽取血样,以评估TAI的患病率、甲状腺功能、免疫细胞绝对数量和百分比。TAI患者甲状腺功能异常的患病率与无TAI患者相比无显著差异(χ^2=0.484,p>0.05)。与无TAI患者比较,TAI患者的T细胞、B细胞和自然杀伤(NK)细胞的绝对数量和百分比没有显著差异(所有p>0.05)。与无TAI的患者相比,TAI患者的细胞毒性T细胞(Tc)百分比显著降低(p<0.05);同时,Th/Tc比率显著增加(p<0.05)。RIF患者的TAI可能是由于伴侣之间潜在的密切组织相容性引起,降低的Tc百分比和增加的Th/Tc比率可能是RIF女性不良妊娠结果的另一个影响因素。     

Development of the embryonic heat shock response and the impact of repeated thermal stress in early stage lake whitefish (Coregonus clupeaformis) embryos

Lake whitefish (Coregonus clupeaformis) embryos were exposed to thermal stress (TS) at different developmental stages to determine when the heat shock response (HSR) can be initiated and if it is altered by exposure to repeated TS. First, embryos were subject to one of three different TS temperatures (6, 9, or 12 °C above control) at 4 points in development (21, 38, 60 and 70 days post-fertilisation (dpf)) for 2 h followed by a 2 h recovery to understand the ontogeny of the HSR. A second experiment explored the effects of repeated TS on the HSR in embryos from 15 to 75 dpf. Embryos were subjected to one of two TS regimes; +6 °C TS for 1 h every 6 days or +9 °C TS for 1 h every 6 days. Following a 2 h recovery, a subset of embryos was sampled. Our results show that embryos could initiate a HSR via upregulation of heat shock protein 70 (hsp70) mRNA at all developmental ages studied, but that this response varied with age and was only observed with a TS of +9 or +12 °C. In comparison, when embryos received multiple TS treatments, hsp70 was not induced in response to the 1 h TS and 2 h recovery, and a downregulation was observed at 39 dpf. Downregulation of hsp47 and hsp90α mRNA was also observed in early age embryos. Collectively, these data suggest that embryos are capable of initiating a HSR at early age and throughout embryogenesis, but that repeated TS can alter the HSR, and may result in either reduced responsiveness or a downregulation of inducible hsps. Our findings warrant further investigation into both the short- and long-term effects of repeated TS on lake whitefish development.