Soil surface colonization by phototrophic indigenous organisms,in two contrasted soils treated by formulated maize herbicide mixtures

Soil phototrophic microorganisms, contributors to soil health and food webs, share their particular metabolism with plants. Current agricultural practices employ mixtures of pesticides to ensure the crops yields and can potentially impair these non-target organisms. However despite this environmental reality, studies dealing the susceptibility of phototrophic microorganisms to pesticide mixtures are scarce. We designed a 3 months microcosm study to assess the ecotoxicity of realistic herbicide mixtures of formulated S-metolachlor (Dual Gold Safeneur^®), mesotrione (Callisto^®) and nicosulfuron (Milagro^®) on phototrophic communities of two soils (Limagne vertisol and Versailles luvisol). The soils presented different colonizing communities, with diatoms and chlorophyceae dominating communities in Limagne soil and cyanobacteria and bryophyta communities in Versailles soil. The results highlighted the strong impairment of Dual Gold Safeneur^® treated microcosms on the biomass and the composition of both soil phototrophic communities, with no resilience after a delay of 3 months. This study also excluded any significant mixture effect on these organisms for Callisto^® and Milagro^® herbicides. We strongly recommend carrying on extensive soil studies on S-metolachlor and its commercial formulations, in order to reconsider its use from an ecotoxicological point of view.     

Participating in an exercise group after anterior cruciate ligament reconstruction (ACLR) is perceived to influence psychosocial factors and successful recovery: a focus group qualitative study

ObjectivesTo explore the patients’ experiences of participating in an exercise group following anterior cruciate ligament reconstruction (ACLR).DesignHermaneutic phenomenological qualitative study of two focus groups.SettingOutpatient care, private rehabilitation centre.ParticipantsNine adults who had participated in an exercise group led by a physiotherapist following ACLR.ResultsThree major themes emerged from the data: psychosocial factors, physical outcomes and identity of the exercise group. The most significant perception of engaging in an exercise group following ACLR was its influence on psychosocial factors, especially motivation, self-confidence and social support. The group influenced the participants’ motivation, enjoyment and commitment to exercise during their rehabilitation. Social support, self-confidence and reassurance were mostly gained. The participants taking part in sport experienced the ACLR group as a substitute for sport trainings. The group was perceived to help enhance speed of recovery and facilitate the return to normal life, especially for participants with lower reported motivation and adherence to home-exercises. The authors interpreted that the subjective physical outcomes’ improvements described by all the participants was potentially an increased level of self-efficacy.The challenging role of the physiotherapist was highlighted as well as the promotion of shared accountability between patients and the group’s leader. The exercise group’s identity was questioned within the rehabilitation process, and the need for more knowledge of its existence in order to promote exercise group therapy was suggested.ConclusionParticipating in an exercise group therapy influences psychosocial factors such as motivation, self-confidence, social support, potentially self-efficacy and helps enhance a faster successful recovery following ACLR. Our findings indicate that participants with a lower reported adherence to home-exercises may especially benefit from it.     

Immunodetection of Tau microtubule-associated protein in human sperm and testis

Dear Editor,
The cytosolic protein Tau is naturally present in human neurons, where it has a pivotal role in controlling microtubule stability. Hyperphosphorylation of Tau （observed during neurodegenerative diseases, such as Alzheimer＇s disease） impairs the protein＇s ability to bind microtubules. This results in microtubule disassembly and the formation of Tau aggregates, Tau protein is also widely expressed in peripheral tissues. In the male reproductive system, screening for Tau has focused solely on the rodent and bovine testis. In the present study, we used immunofluorescence and immunoenzymatic techniques （with a Tau-specific antibody） to investigate the presence of Tau protein in human ejaculated sperm and testicular tissue.     

Impaired brain energy metabolism in the BACHD mouse model of Huntington's disease: critical role of astrocyte–neuron interactions

Huntington''s disease (HD) is caused by cytosine-adenine-guanine (CAG) repeat expansions in the huntingtin (Htt) gene. Although early energy metabolic alterations in HD are likely to contribute to later neurodegenerative processes, the cellular and molecular mechanisms responsible for these metabolic alterations are not well characterized. Using the BACHD mice that express the full-length mutant huntingtin (mHtt) protein with 97 glutamine repeats, we first demonstrated localized in vivo changes in brain glucose use reminiscent of what is observed in premanifest HD carriers. Using biochemical, molecular, and functional analyses on different primary cell culture models from BACHD mice, we observed that mHtt does not directly affect metabolic activity in a cell autonomous manner. However, coculture of neurons with astrocytes from wild-type or BACHD mice identified mutant astrocytes as a source of adverse non-cell autonomous effects on neuron energy metabolism possibly by increasing oxidative stress. These results suggest that astrocyte-to-neuron signaling is involved in early energy metabolic alterations in HD.     

Effects of vitamin D in the elderly population: current status and perspectives

Besides its well-known effect on bone metabolism, recent researches suggest that vitamin D may also play a role in the muscular, immune, endocrine, and central nervous systems. Double-blind RCTs support vitamin D supplementation at a dose of 800 IU per day for the prevention of falls and fractures in the senior population. Ecological, case–control and cohort studies have suggested that high vitamin D levels were associated with a reduced risk of autoimmune diseases, type 2 diabetes, cardio-vascular diseases and cancer but large clinical trials are lacking today to provide solid evidence of a vitamin D benefit beyond bone health. At last, the optimal dose, route of administration, dosing interval and duration of vitamin D supplementation at a specific target dose beyond the prevention of vitamin D deficiency need to be further investigated.     

Improving the Quality of EDTA-treated Blood Specimens from Mice

Nonterminal blood sampling in laboratory mice is a very common procedure. With the goal of improving animal welfare, different sampling sites and methods have been compared but have not achieved a consensus. Moreover, most of these studies overlooked the quality of blood specimens collected. The main preanalytical concern with EDTA-treated blood specimens for hematology analyses is platelet aggregation, which is known to cause analytical errors. Our objective was to find a nonterminal blood sampling method with minimal adverse effects on mice and few or no platelet aggregates. We tested and compared 2 collection sites, 4 sampling methods, and 3 antithrombotic drugs in 80 C57BL6/j male and female mice by evaluating platelet aggregates on blood smears and platelet, WBC, and RBC counts. In addition, the blood collection process was carefully evaluated, and adverse effects were recorded. Platelet aggregation was lower in specimens collected from the jugular vein than from the facial vein, with no effect of the sampling device or the presence of an antithrombotic additive. Highly aggregated specimens were significantly associated with lower platelet counts, whereas aggregation had no effect on WBC or RBC counts. Adverse events during sampling were significantly associated with more numerous platelet aggregates. The jugular vein is thus a satisfactory sampling site in mice in terms of both animal welfare and low platelet aggregation. Using antithrombotic agents appears to be unnecessary, whereas improving sampling conditions remains a key requirement to ensure the quality of EDTA-treated blood specimens from mice.

Industrial and academic research often require hematology analyses of mouse blood. Consequently, many terminal and nonterminal techniques have become available for blood sampling in mice.^{12,21,27,40,42,53} Preanalytical variation in clinical pathology is known to be a major issue.^5,45,49 Although the effects of the blood sampling method on animal welfare have been the subject of many preanalytical hematology and biochemical analyses,^{1,6,8,9,15,16,18,24-26,36,47,50-52,54} no agreement has been reached regarding the optimal method for nonterminal blood collection in mice and, to our knowledge, only a few investigations^1,8,15,16,18 have addressed the quality of the resulting blood specimens.Our own experience of hematology measurements from nonterminal mouse EDTA-blood specimens is that some specimens show both visible clots and platelet aggregation, the latter being detected only from microscopic examination of blood smears.³³ Whereas specimens with visible clots can be eliminated, microscopic platelet aggregates can also interfere with hematology analyses or cause analytical errors, as has been reported in other species including cats.^13,22,31,39 These abnormalities require repeat sampling when possible; otherwise, the number of validated results is decreased. EDTA-treated mouse blood is especially prone to platelet aggregation and clotting.^14,28,43 This characteristic leads to errors in platelet counts (pseudothrombocytopenia) and possible misidentification of platelet aggregates as eosinophils, resulting in false leukocytosis and eosinophilia.¹⁴ In vitro platelet aggregation in mice is due to high platelet counts^34,43 and is influenced by numerous preanalytical factors including the sampling method, collection site, specimen processing, anticoagulant used, the blood:anticoagulant ratio, the mouse strain and genetic alterations.^19,28,30,43 The literature on the influence of preanalytical factors on the quality of CBC analyses in mice is scant,⁴³ and no agreement has yet been reached regarding the optimal method for nonterminal blood collection in mice. In humans and various animal species, platelet aggregation can be reduced by adding platelet aggregation inhibitors that act at different steps of aggregation. To our knowledge, the addition of such inhibitors to mouse whole blood has not been tested as a means to improve the quality of mice EDTA-treated blood specimens.The aim of this study was therefore to identify the best preanalytical conditions for nonterminal blood collection in mice, based on animal welfare, scores of platelet aggregation, and platelet, RBC, and WBC counts. The hypotheses we tested were that 1) adding an antithrombotic drug (or multiple such drugs) to the EDTA-treated blood specimen would prevent or at least significantly lower platelet aggregation, 2) the site and the method of collection influence in vitro platelet aggregation, and 3) high-quality blood sampling is a key to reducing platelet aggregation in blood specimens.     

Toll-like receptor 9 signaling mediates the anti-inflammatory effects of probiotics in murine experimental colitis

BACKGROUND & AIMS: We tested whether the attenuation of experimental colitis by live probiotic bacteria is due to their immunostimulatory DNA, whether toll-like receptor (TLR) signaling is required, and whether nonviable probiotics are effective. METHODS: Methylated and unmethylated genomic DNA isolated from probiotics (VSL-3), DNAse-treated probiotics and Escherichia coli (DH5 alpha) genomic DNA were administered intragastrically (i.g.) or subcutaneously (s.c.) to mice prior to the induction of colitis. Viable or gamma-irradiated probiotics were administered i.g. to wild-type mice and mice deficient in different TLR or in the adaptor protein MyD88, 10 days prior to administration of dextran sodium sulfate (DSS) to their drinking water and for 7 days thereafter. RESULTS: Intragastric and s.c. administration of probiotic and E. coli DNA ameliorated the severity of DSS-induced colitis, whereas methylated probiotic DNA, calf thymus DNA, and DNase-treated probiotics had no effect. The colitis severity was attenuated to the same extent by i.g. delivery of nonviable gamma-irradiated or viable probiotics. Mice deficient in MyD88 did not respond to gamma-irradiated probiotics. The severity of DSS-induced colitis in TLR2 and TLR4 deficient mice was significantly decreased by i.g. administration of gamma-irradiated probiotics, whereas, in TLR9-deficient mice, gamma-irradiated probiotics had no effect. CONCLUSIONS: The protective effects of probiotics are mediated by their own DNA rather than by their metabolites or ability to colonize the colon. TLR9 signaling is essential in mediating the anti-inflammatory effect of probiotics, and live microorganisms are not required to attenuate experimental colitis because nonviable probiotics are equally effective.