Probiotics supplementation reduces cigarette smoke-induced damage in the respiratory micro-architecture of mice / Suplementação com probióticos reduz os danos causados pela fumaça de cigarro na microarquitetura respiratória de camundongos

This study evaluated the protective efficacy of probiotics supplementation against cigarette smoke-induced lung emphysema, inflammation, and loss of cilia in mice. Probiotics are known to promote mucosal tolerance and mitigate respiratory injuries. Twenty-four adult mice were randomly divided into three groups: control (Ctr), cigarette smoke (CS), and cigarette smoke + probiotics (CS+P). Probiotics were given for 7 days before exposure to smoke in the CS+P group. Tissue samples of the trachea (goblet cell count and index, loss of cilia), lungs (airspace distention), and bronchoalveolar lavage fluid (BALF) were collected and processed. The results showed a significant increase in acidic and neutral goblet cells in the CS group compared to the Ctr and CS+P groups (P < 0.05). Overall, goblet cell number and index were lower in the CS+P group (41.71 ± 5.76, 0.67 ± 0.073) than CS group (56.28 ± 5.34, 1.31 ± 0.28). Inflammatory cells and loss of cilia significantly decreased in mice fed probiotics before exposure to cigarette smoke (P < 0.05). Lung emphysema was also significantly reduced in the CS+P group compared to the CS group (P < 0.05). In conclusion, dietary supplementation of probiotics reduced lung emphysema, inflammatory cells, goblet cell index, and loss of cilia under conditions of cigarette smoke exposure in mice.(AU)

O presente trabalho avaliou a eficácia da suplementação com probióticos contra a indução de enfisema, inflamação e perda de cílios por fumaça de cigarro em camundongos. Sabe-se que os probióticos promovem a tolerância da mucosa e mitigam as injúrias respiratórias. Vinte e quatro camundongos foram divididos, ao acaso, em três grupos: controle (CTR), fumaça de cigarro (CS) e fumaça de cigarro + probióticos (CS+P). Os probióticos foram fornecidos por sete dias antes da exposição à fumaça no grupo CS+P. Foram colhidas e processadas amostras de tecidos da traqueia (contagem de células caliciformes e index, perda de cílios), pulmões (distensão do espaço aéreo) e fluido de lavagem broncoalveolar. Os resultados obtidos revelaram um aumento significativo em células caliciformes acidificadas e neutralizadas no grupo CS quando comparado aos grupos Ctr e CS+P (P<0,05). Os números global e o índice de células caliciformes foram menores no grupo CS+P (41,71+ 5,76; 0,67+ 0,073) que no grupo CS (56,28+ 5,34 e 1,131+ 0,28). As células inflamatórias e a perda de cílios decresceram em camundongos alimentados com probióticos antes da exposição à fumaça de cigarro (P<0,05). O enfisema pulmonar também foi significativamente reduzido no grupo CS+P quando comparado ao grupo CS (P<0,05). A conclusão obtida foi que o fornecimento de dieta suplementada com probióticos reduziu o enfisema pulmonar, as células inflamatórias, o índice de células caliciformes e a perda de cílios nos camundongos expostos à fumaça de cigarro.(AU)

Aurora A Kinase (AURKA) is required for male germline maintenance and regulates sperm motility in the mouse.

Aurora A kinase (AURKA) is an important regulator of cell division and is required for assembly of the mitotic spindle. We recently reported the unusual finding that this mitotic kinase is also found on the sperm flagellum. To determine its requirement in spermatogenesis, we generated conditional knockout animals with deletion of the Aurka gene in either spermatogonia or spermatocytes to assess its role in mitotic and postmitotic cells, respectively. Deletion of Aurka in spermatogonia resulted in disappearance of all developing germ cells in the testis, as expected, given its vital role in mitotic cell division. Deletion of Aurka in spermatocytes reduced testis size, sperm count, and fertility, indicating disruption of meiosis or an effect on spermiogenesis in developing mice. Interestingly, deletion of Aurka in spermatocytes increased apoptosis in spermatocytes along with an increase in the percentage of sperm with abnormal morphology. Despite the increase in abnormal sperm, sperm from spermatocyte Aurka knockout mice displayed increased progressive motility. In addition, sperm lysate prepared from Aurka knockout animals had decreased protein phosphatase 1 (PP1) activity. Together, our results show that AURKA plays multiple roles in spermatogenesis, from mitotic divisions of spermatogonia to sperm morphology and motility.

Single-cell analysis of ploidy and the transcriptome reveals functional and spatial divergency in murine megakaryopoiesis.

Megakaryocytes (MKs), the platelet progenitor cells, play important roles in hematopoietic stem cell (HSC) maintenance and immunity. However, it is not known whether these diverse programs are executed by a single population or by distinct subsets of cells. Here, we manually isolated primary CD41+ MKs from the bone marrow (BM) of mice and human donors based on ploidy (2N-32N) and performed single-cell RNA sequencing analysis. We found that cellular heterogeneity existed within 3 distinct subpopulations that possess gene signatures related to platelet generation, HSC niche interaction, and inflammatory responses. In situ immunostaining of mouse BM demonstrated that platelet generation and the HSC niche-related MKs were in close physical proximity to blood vessels and HSCs, respectively. Proplatelets, which could give rise to platelets under blood shear forces, were predominantly formed on a platelet generation subset. Remarkably, the inflammatory responses subpopulation, consisting generally of low-ploidy LSP1+ and CD53+ MKs (≤8N), represented ∼5% of total MKs in the BM. These MKs could specifically respond to pathogenic infections in mice. Rapid expansion of this population was accompanied by strong upregulation of a preexisting PU.1- and IRF-8-associated monocytic-like transcriptional program involved in pathogen recognition and clearance as well as antigen presentation. Consistently, isolated primary CD53+ cells were capable of engulfing and digesting bacteria and stimulating T cells in vitro. Together, our findings uncover new molecular, spatial, and functional heterogeneity within MKs in vivo and demonstrate the existence of a specialized MK subpopulation that may act as a new type of immune cell.

Waking experience modulates sleep need in mice.

BACKGROUND: Homeostatic regulation of sleep is reflected in the maintenance of a daily balance between sleep and wakefulness. Although numerous internal and external factors can influence sleep, it is unclear whether and to what extent the process that keeps track of time spent awake is determined by the content of the waking experience. We hypothesised that alterations in environmental conditions may elicit different types of wakefulness, which will in turn influence both the capacity to sustain continuous wakefulness as well as the rates of accumulating sleep pressure. To address this, we compared the effects of repetitive behaviours such as voluntary wheel running or performing a simple touchscreen task, with wakefulness dominated by novel object exploration, on sleep timing and EEG slow-wave activity (SWA) during subsequent NREM sleep. RESULTS: We find that voluntary wheel running is associated with higher wake EEG theta-frequency activity and results in longer wake episodes, as compared with exploratory behaviour; yet, it does not lead to higher levels of EEG SWA during subsequent NREM sleep in either the frontal or occipital derivation. Furthermore, engagement in a touchscreen task, motivated by food reward, results in lower SWA during subsequent NREM sleep in both derivations, as compared to exploratory wakefulness, even though the total duration of wakefulness is similar. CONCLUSION: Overall, our study suggests that sleep-wake behaviour is highly flexible within an individual and that the homeostatic processes that keep track of time spent awake are sensitive to the nature of the waking experience. We therefore conclude that sleep dynamics are determined, to a large degree, by the interaction between the organism and the environment.

Effect of Cetrorelix administration on ovarian stimulation in aged mice.

In mice, ovarian stimulation via hormone administration is an effective method for obtaining many ova simultaneously, but its effect is reduced by the influence of aging. In this study, we demonstrate that this problem can be improved by administering the gonadotropin-releasing hormone antagonist Cetrorelix prior to ovarian stimulation. Before 12-month-old female mice were injected with 5 IU pregnant mare serum gonadotropin and 5 IU human chorionic gonadotropin, we administered 5 µg/kg Cetrorelix for 7 consecutive days (7 times) or 3 times once every 3 days. As a result, 8.7 ± 1.9 (mean ± SEM, n=10) and 9.8 ± 1.3 (n=10) oocytes were obtained, respectively, as opposed to 4.7 ± 1.2 oocytes (n=9) in the case of no administration. Collagen staining of ovarian tissue showed that Cetrorelix administration reduced the degree of fibrosis, which improved ovarian function. In addition, equivalent fertilization and fetal development rates between control and Cetrorelix-treated aged mouse-derived oocytes were confirmed by in vitro fertilization and embryo transfer (Fertilization rate; control: 92.2% vs. 3 times: 96.9%/7 times: 88.5%, Birth rate; control: 56.4% vs. 3 times: 58.3%/7 times: 51.8%), indicating the normality of the obtained oocytes. It is concluded that Cetrorelix improved the effect of superovulation in aged mice without reducing oocyte quality. This procedure will contribute to animal welfare by extending the effective utilization of aged female breeding mice.

Antinociceptive and anti-inflammatory effects of cellular and extracellular extracts from microalga Chlamydomonas pumilioniformis on mice

Microalga species have attracted interest as a source of bioactive compounds with several pharmacological activities. Previous studies reported that microalgae from the genus Chlamydomonas have anti-inflammatory and antioxidant properties. In this study, antinociceptive and anti-inflammatory activities of two extracts from microalga Chlamydomonas pumilioniformis were investigated. Cellular and extracellular extracts were prepared from a 14 day-batch culture in WC medium at the end of exponential growth and their carbohydrate contents were determined. Antinociceptive effects of extracts were evaluated by writhing and formalin-induced nociception tests, while the anti-inflammatory activity was analyzed by formalin-induced paw edema in mice. The analysis of dissolved carbohydrates detected amounts of 90 and 20 µg mL-1 of total carbohydrate in cellular and extracellular extracts, respectively. Cellular extract was mainly composed of glucose, but with significant proportions of arabinose, galactose and mannose and/or xylose and minor ones of fucose, rhamnose, amino sugars and uronic acids. Extracellular extract was composed of a similar proportion of glucose, galactose and mannose/xylose, besides significant ones of arabinose, fucose and galacturonic acid. Intraperitoneal administration of extracts significantly reduced writhing response in mice. In the formalin test, the extracellular extract inhibited both formalin phases, while the cellular extract was only effective in the late phase. Furthermore, extracts reduced the formalin-induced paw edema. In sum, we showed, for the first time, that C. pumilioniformis can be an important source of polysaccharides with anti-inflammatory and antinociceptive effects.

Associação de arcabouço de polipropileno e células tronco mesenqimais para uso em engenharia de tecido / Association of polypropylene scaffolds and mesenchymal stem cells for use in tissue engineering

A engenharia de tecidos tem como objetivo substituir tecidos danificados, manipulando células, confecção de arcabouços e a utilização de moléculas que estimulem o tecido. A proposta deste estudo foi avaliar duas técnicas de cultivo de células-tronco mesenquimais (MSC) em diferentes placas de cultura, utilizando dois tipos de telas de polipropileno (macroporoso e microporoso), para obter as melhores condições de interação entre a tela e as células, e definir uma proposta de protético para engenharia de tecidos. As telas de polipropileno foram cultivadas com células-tronco mesenquimais de tecido adiposo (ADSCs) isoladas de camundongos C57B1/6 GFP+ durante quinze dias em placas revestidas com metacrilato ou não revestidas com metacrilato. A quantidade de ADSCs aderidas foram verificadas diariamente em Câmara de Neubauer e através de uma curva de crescimento realizada pelo ensaio MTT. As ADSCs aderidas às malhas foram visualizadas com marcação de DAPI, panóticas, hematoxilina e eosina imuno-histoquímica e imunofluorescência. O melhor protocolo foi na tela microporosa, no o período de sete dias de cultivo e em placas sem metacrilato. Conclui-se que a tela de polipropileno fornece um bom suporte para as ADSCs se aderirem podendo ser utilizada na engenharia de tecidos.

Tissue engineering replaces injured tissues by manipulating cells, making scaffolds, and using molecules that stimulate the tissue. Mesenchymal stem cells (MSCs) are good candidates for tissue engineering, as this is one of the cell types which are recruited to repair injured tissues. Scaffolds are structural devices that allow cell fixation and migration, with polypropylene meshes being an example. This study aims to evaluate the culture of adipose tissue-derived mesenchymal stem cells (ADSCs), isolated from C57Bl/6 GFP + mice, in two types of polypropylene meshes (macroporous and microporous) in conventional culture plates and plates coated with methacrylate, over a period of fifteen days. The objective was to obtain the best interaction protocol between the mesh and the cells. The choice of the best method was based on adherence, maintenance of adherence and viability during culture. The amount of ADSCs adhering was checked daily by counting in a Neubauer Chamber and by using a growth curve performed with the MTT assay. The ADSCs adhering to the meshes were visualized with DAPI, panotic, hematoxylin and eosin, immunohistochemistry (integrin), and immunofluorescence (actin). ADSCs adhere to all forms of culture and to the two types of polypropylene mesh. ADSCs adhered more to the microporous mesh, within the seven day period of culture and in the plates without methacrylate. Thus, polypropylene meshes offer a good scaffold for ADSCs to adhere to.

Towards a fully automated surveillance of well-being status in laboratory mice using deep learning: Starting with facial expression analysis.

Assessing the well-being of an animal is hindered by the limitations of efficient communication between humans and animals. Instead of direct communication, a variety of parameters are employed to evaluate the well-being of an animal. Especially in the field of biomedical research, scientifically sound tools to assess pain, suffering, and distress for experimental animals are highly demanded due to ethical and legal reasons. For mice, the most commonly used laboratory animals, a valuable tool is the Mouse Grimace Scale (MGS), a coding system for facial expressions of pain in mice. We aim to develop a fully automated system for the surveillance of post-surgical and post-anesthetic effects in mice. Our work introduces a semi-automated pipeline as a first step towards this goal. A new data set of images of black-furred laboratory mice that were moving freely is used and provided. Images were obtained after anesthesia (with isoflurane or ketamine/xylazine combination) and surgery (castration). We deploy two pre-trained state of the art deep convolutional neural network (CNN) architectures (ResNet50 and InceptionV3) and compare to a third CNN architecture without pre-training. Depending on the particular treatment, we achieve an accuracy of up to 99% for the recognition of the absence or presence of post-surgical and/or post-anesthetic effects on the facial expression.

Dynamic changes in cytoskeleton proteins of olfactory ensheathing cells induced by radiofrequency electromagnetic fields.

Several evidences have suggested the ability of radiofrequency electromagnetic fields to influence biological systems, even if the action mechanisms are not well understood. There are few data on the effect of radiofrequency electromagnetic fields on self-renewal of neural progenitor cells. A particular glial type that shows characteristics of stem cells is olfactory ensheathing cells (OECs). Herein, we assessed the non-thermal effects induced on OECs through radiofrequency electromagnetic fields changing the envelope of the electromagnetic wave. Primary OEC cultures were exposed to continuous or amplitude-modulated 900 MHz electromagnetic fields, in the far-field condition and at different exposure times (10, 15, 20 min). The expression of OEC markers (S-100 and nestin), cytoskeletal proteins (GFAP and vimentin), apoptotic pathway activation by caspase-3 cleavage and cell viability were evaluated. Our results highlight that 20 min of exposure to continuous or amplitude-modulated 900 MHz electromagnetic fields induced a different and significant decrease in cell viability. In addition, according to the electromagnetic field waveform, diverse dynamic changes in the expression of the analysed markers in OECs and activation of the apoptotic pathway were observed. The data suggest that radiofrequency electromagnetic fields might play different and important roles in the self-renewal of OEC stem cells, which are involved in nervous system repair.

Defining body-weight reduction as a humane endpoint: a critical appraisal.

In many animal experiments scientists and local authorities define a body-weight reduction of 20% or more as severe suffering and thereby as a potential parameter for humane endpoint decisions. In this study, we evaluated distinct animal experiments in multiple research facilities, and assessed whether 20% body-weight reduction is a valid humane endpoint criterion in rodents. In most experiments (restraint stress, distinct models for epilepsy, pancreatic resection, liver resection, caloric restrictive feeding and a mouse model for Dravet syndrome) the animals lost less than 20% of their original body weight. In a glioma model, a fast deterioration in body weight of less than 20% was observed as a reliable predictor for clinical deterioration. In contrast, after induction of chronic diabetes or acute colitis some animals lost more than 20% of their body weight without exhibiting major signs of distress. In these two animal models an exclusive application of the 20% weight loss criterion for euthanasia might therefore result in an unnecessary loss of animals. However, we also confirmed that this criterion can be a valid parameter for defining the humane endpoint in other animal models, especially when it is combined with additional criteria for evaluating distress. In conclusion, our findings strongly suggest that experiment and model specific considerations are necessary for the rational integration of the parameter 'weight loss' in severity assessment schemes and humane endpoint criteria. A flexible implementation tailored to the experiment or intervention by scientists and authorities is therefore highly recommended.

Tamoxifen administration in pregnant mice can be deleterious to both mother and embryo.

Since it was introduced 20 years ago, tamoxifen-inducible genetic recombination in vivo has become a standard tool in many fields. This technique has great utility, allowing precise temporal and spatial gene recombination mediated by expression of a Cre recombinase-oestrogen receptor hormone binding domain fusion protein. It is frequently used in developmental biology, either for accurate spatio-temporal gene deletion or for lineage-labelling. Administration of high doses of tamoxifen can rapidly induce abortion in pregnant mice but this can be partially overcome by progesterone co-administration. However, administration of tamoxifen to pregnant mice early in pregnancy may have potentially lethal effects on the mother independently of abortion, and can also severely perturb embryonic development. Despite this, only a few published studies mention this fact in passing, and standard parameters for successful or unsuccessful use of tamoxifen in pregnant mice have not been reported. Therefore, in the interests of providing a framework for more humane animal research, we describe our experiences of tamoxifen administration during early gestation in mice. These observations should assist the design of future studies in accordance with the principles of the three Rs (Replacement, Reduction and Refinement of Animals in Research).

Physiological and pathological impact of AQP1 knockout in mice.

Aquaporin 1 (AQP1) is a glycoprotein responsible for water passive transport quickly across biological membrane. Here, we reviewed the structural and functional impacts of AQP1 knockout (AQP1-KO) in animal or cell culture models. AQP1 gene deletion can cause a large number of abnormalities including the disturbance in epithelial fluid secretion, polyhydramnios, deficiency of urinary concentrating function, and impairment of pain perception. AQP1-KO mice also displayed aberrations of cardiovascular, gastrointestinal and hepatobiliary, and kidney functions as well as placenta and embryo development. Moreover, AQP1-KO perturbed tumor angiogenesis and led to reduced brain injury upon trauma. On the cellular level, AQP1-KO caused neuroinflammation, aberrant cell proliferation and migration, and macrophages infiltration. Mechanistic studies confirmed that AQP1 gene products regulate the secretory function and participated in balancing the osmotic water flux across the peritoneal membrane. The available data indicated that AQP1 might serve as a potential target for developing novel therapeutic approaches against diverse human diseases.

Effect of Predator Stress on the Reproductive Performance of Female Mice After Nonsurgical Embryo Transfer.

Predator Stress Can Exert Detrimental Effects on Female Mammals, Leading to Disrupted Reproduction. Although Many Studies Have Addressed the Effects of Predator Stress on Reproductive Output in Rodents, Few Studies Have Focused on the Effect of Visual or Auditory Stress on Pregnant Females. in This Study, We Investigated the Possible Effect of Predator Stress, Either Visual Only or Combined Visual and Auditory (visual+auditory), on the Reproductive Performance of Female Mice After Nonsurgical Embryo Transfer. Reproductive Performance Was Assessed As Pregnancy Rate, Implantation Rate, Gestation Length, Live Pup Rate, and Neonatal Birth Weight. Moreover, Serum Cortisol and Progesterone Levels in Dams Were Measured by Using Electrochemiluminescence Immunoassay. Exposure to Predator (cat) Stress Did Not Lead to a Significant Change in Pregnancy Rates in the Tested Mice. However, the Stressed Mice Showed Significantly Decreased Implantation Rates Compared with the Control Group. Similarly, the Live Pup Rate and Neonatal Birth Weight Were Significantly Lower in the Group Exposed to Preda- Tor Stress Than in the Control Group. Furthermore, Mice Exposed to Visual+auditory Stress Showed a Significant Reduction in Gestation Length Compared with the Control Mice. Our Data Showed That Predator Visual+auditory Stress As Combined Stimuli Significantly Increased Serum Cortisol Level. in Contrast, Progesterone Levels Did Not Significantly Vary Among the Experimental Groups. Taken Together, Our Findings Imply That Predator Stress Adversely Affects the Reproductive Efficiency of Pregnant Mice By Decreasing the Implantation Rate, Live Birth Rate, and Neonatal Birth Weight and by Prolonging Gestation Length.

Effects of different odours on the reproductive success of Mus musculus as an alternative method of control.

BACKGROUND: The house mouse (Mus musculus) is a cosmopolitan rodent that has become adapted to living in close association with humans and is considered a serious pest because it poses a risk to human health, and causes economic losses due to food and crop consumption and damage to buildings. Its control in livestock farms is achieved mainly through the application of anticoagulant rodenticides, but the effect of these compounds is limited due to the presence of resistant individuals and aversive behaviours. A potential alternative method is the use of chemical signals to reduce rodent reproductive success. In this study, we assessed the effects of odours from an unfamiliar male, 17ß-oestradiol, overcrowding, cat urine and 2,5-dihydro-2,4,5-trimethylthiazoline (TMT) on the reproductive success of laboratory Mus musculus females. RESULTS: According to the generalized linear mixed models, cat urine odour increased the proportion of abortions per female, unfamiliar male odour decreased the mean number of offspring born per female, and TMT had an overall negative effect on mean offspring production at birth and at weaning. The other odours had no significant effects on reproductive success. CONCLUSIONS: TMT seems to be the best candidate for population control because it caused a decrease in the mean number of offspring born and the mean number of live offspring at weaning. TMT also has the advantage of being available in commercial forms. To be useful for rodent management in field conditions, these results should be confirmed using wild house mice females. © 2019 Society of Chemical Industry.

Identification and Field Testing of Volatile Components in the Sex Attractant Pheromone Blend of Female House Mice.

Recently, it was reported (i) that the sex pheromone blend of male house mice, Mus musculus, comprises not only volatile components (3,4-dehydro-exo-brevicomin; 2-sec-butyl-4,5-dihydrothiazole) but also a component of low volatility (the sex steroid testosterone), and (ii) that the sex steroids progesterone and estradiol are sex pheromone components of female house mice. Here we tested the hypothesis that the sex attractant pheromone blend of female mice, analogous to that of male mice, also comprises volatile pheromone components. Analyzing by GC-MS the head space volatiles of bedding soiled with urine and feces of laboratory-kept females and males revealed three candidate pheromone components (CPCs) that were adult female-specific: butyric acid, 2-methyl butyric acid and 4-heptanone. In a two-choice laboratory experiment, adult males spent significantly more time in the treatment chamber baited with both the synthetic steroids (progesterone, estradiol) and the synthetic CPCs than in the paired control chamber baited only with the synthetic steroids. In field experiments, trap boxes baited with both the CPCs and the steroids captured 6.7-times more adult males and 4.7-times more juvenile males than trap boxes baited with the steroids alone. Conversely, trap boxes baited with both the CPCs and the steroids captured 4.3-times more adult males and 2.7-fold fewer adult females than trap boxes baited with the CPCs alone. In combination, these data support the conclusion that butyric acid, 2-methyl butyric acid and 4-heptanone are part of the sex attractant pheromone of female house mice. With progesterone and estradiol being pheromone components of both female brown rats, Rattus norvegicus, and female house mice, these three volatile components could impart specificity to the sexual communication system of house mice, brown rats and possibly other rodent species.

Identifying and Implementing Endpoints for Geriatric Mice.

The types of changes in physical appearance and behavior that occur in elderly people similarly develop in elderly animals. Signs and symptoms that might cause concern in younger people or mice may be normal in their elderly but generally healthy counterparts. Although numerous scoring methods have been developed to assess rodent health, these systems were often designed for young adults used in specific types of research, such as cancer or neurologic studies, and therefore may be suboptimal for assessing aging rodents. Approaches known as frailty assessments provide a global evaluation of the health of aged mice, rats, and people, and mouse frailty scores correlate well with the likelihood of death. Complementing frailty assessment, prediction of imminent death in aged mice can often be accomplished by focusing on 2 objective parameters-body weight and temperature. Before they die, many (but not all) mice develop marked reductions in body weight and temperature, thus providing signs that close monitoring, intervention, or preemptive euthanasia may be necessary. Timely preemptive euthanasia allows antemortem collection of data and samples that would be lost if spontaneous death occurred; preemptive euthanasia also limits terminal suffering. These approaches to monitoring declining health and predicting death in elderly research mice can aid in establishing and implementing timely interventions that both benefit the research and reduce antemortem suffering.

A comparative study on effects of static electric field and power frequency electric field on hematology in mice.

With the development of the ultra high voltage transmission technology, the voltage level of transmission line rised. Accordingly, the strength of electric field in the vicinity of transmission line increased, thus possible health effects from electric field have caused many public attentions. In this study, in order to compare effects induced by static electric field (SEF) and power frequency electric field (PFEF) on immune function, Institute of Cancer Research (ICR) mice were exposed to 35 kV/m SEF (0 Hz) and PFEF (50 Hz),respectively. Several indicators of white blood cell, red blood cell as well as hemoglobin in peripheral blood were tested after exposure of 7, 14 and 21 days, respectively. There was no significant difference in any indicators under SEF exposure of 35 kV/m for 7d, 14d and 21d between experimental group and control group. Under the PFEF exposure of 35 kV/m, white blood cell count significantly reduced after exposure of 7d, 14d and 21d. Meanwhile, red blood cell count significantly reduced after exposure of 7d, and returned to normal level through the compensatory response of organism after exposure of 14d and 21d. Hemoglobin concentration significantly decreased only after exposure of 21d. Based on tested results of hematological indicators, SEF exposure of 35 kV/m did not affect immune functions in mice but PFEF exposure of 35 kV/m could cause a decline of immune function. This difference of effects from SEF and PFEF on immune function was possibly caused by the difference of the degree of molecular polarization and ion migration in organism under exposure of two kinds of electric fields.

Perfect chronic skeletal muscle regeneration in adult spiny mice, Acomys cahirinus.

The spiny mouse, Acomys cahirinus, is an adult mammal capable of remarkable feats of scar-free tissue regeneration after damage to several organs including the skin and the heart. Here we investigate the regenerative properties of the skeletal muscle of A. cahirinus tibialis anterior in comparison to the lab mouse, Mus musculus. The A. cahirinus TA showed a similar distribution of myosin heavy chain fibre types and a reduced proportion of oxidative fibres compared to M. musculus. There were differences in the matrix components of the TA with regard to collagen VI and the biomechanical properties. A. cahirinus TA regenerated faster with a more rapid induction of embryonic myosin and higher levels of dystrophin than in M. musculus fibres. There were lower levels of inflammation (NF-kB), fibrosis (TGFß-1, collagens) and higher levels of the anti-inflammatory cytokine Cxcl12. There was a difference in macrophage profile between the two species. After multiple rounds of muscle regeneration the M. musculus TA failed to regenerate muscle fibres and instead produced a large numbers of adipocytes whereas the A. cahirinus TA regenerated perfectly. This clearly improved regeneration performance can be explained by differing levels of growth factors such as adiponectin between the two species.

Cohousing Male Mice with and without Segmental Bone Defects.

Spaceflight results in bone loss like that associated with osteoporosis or decreased weight-bearing (for example, high-energy trauma such as explosive injuries and automobile accidents). Thus, the unique spaceflight laboratory on the International Space Station presents the opportunity to test bone healing agents during weightlessness. We are collaborating with NASA and the US Army to study bone healing in spaceflight. Given the unique constraints of spaceflight, study design optimization was required. Male mice were selected primarily because their femur is larger than females', allowing for more reproducible surgical outcomes. However, concern was raised regarding male mouse aggression. In addition, the original spaceflight study design included cohousing nonoperated control mice with mice that had undergone surgery to create a segmental bone defect. This strategy prompted the concern that nonoperated mice would exhibit aggressive behavior toward vulnerable operated mice. We hypothesized that operated and nonoperated male mice could be cohoused successfully when they were cagemates since birth and underwent identical anesthetic, analgesic, preoperative, and postoperative conditions. Using quantitative behavioral scoring, body weight, and organ weight analyses (Student t test and ANOVA), we found that nonoperated and operated C57BL/6 male mice could successfully be housed together. The male mice did not exhibit aggressive behavior toward cagemates, whether operated or nonoperated, and the mice did not show evidence of stress, as indicated by veterinary assessment, or change in body or proportional organ weights. These findings allowed our mission to proceed (launched February 2017) and may inform future surgical study designs, potentially increasing housing flexibility.