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.     

Protective effect of immunization with nonviral antigens against Friend leukemia virus in mice

DBA/2 mice immunized with poly(A).poly(U) complexed with methylated bovine serum albumin and emulsified in Freund's complete adjuvant were protected against challenge with Friend leukemia virus. There was no correlation between the level of antibody to the immunogen in the prechallenge serum and induced resistance to the virus. Although prechallenge sera of mice given the same amount of the duplex in a single inoculum bound 9.7% of poly(A).poly([(3)H]U) input, as compared to 45.3% bound by the prechallenge sera of mice given the immunogen in divided doses, both groups of mice were equally resistant to infection. Immunization with two other nonviral agents, bovine serum albumin fraction V or dinitrophenylated keyhole limpet hemocyanin, induced the same level of protection. A sparing effect of approximately 10(1.5) in infectivity was afforded the immunized mice. Immunization with either poly(A).poly(U) alone or with the carrier methylated bovine serum albumin was ineffective.In addition to antibodies to the respective immunogens, the prechallenge sera of the immunized mice also contained antibody to Friend leukemia virus gp71. The presence of such viral antibodies was not always related to resistance to infection by Friend virus. Some immunized mice that survived infection did not have gp71 antibody in their serum before challenge, and mice immunized with poly(A).poly(U) alone were susceptible to infection, although their prechallenge sera contained antibody to gp71. The mechanism involved in the induction of resistance to infection is not known. The effect may be mediated through a modification of the expression of both endogenous and exogenous type C viruses and affect immunological mechanisms controlling cellular responses.     

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.     

Interleukin 6 in Intact and Injured Mouse Peripheral Nerves

The multifunctional cytokine interleukin 6 (IL-6) has direct growth, survival and differentiation effects on peripheral and central neurons. Furthermore, it can modulate the production by non-neuronal cells of other cytokines and growth factors, and thereby affect nerve cells indirectly. We have studied IL-6 expression and production in intact and injured peripheral nerves of C57/BL/6NHSD mice, which display the normal rapid progression of Wallerian degeneration. The IL-6 mRNA was detected in nerves degenerating in vitro or in vivo , but not in intact nerves. In vitro - and in vivo -degenerating nerve segments and neuroma nerve segments synthesized and secreted IL-6. The onset of IL-6 production was rapid and prolonged. It was detected as early as 2 h after injury and persisted for the entire period of 21 days tested after the injury. Of the non-neuronal cells that reside in intact and injured nerves, macrophages and fibroblasts were the major contributors to IL-6 production. We also studied IL-6 production in intact and injured nerves of mutant C57BL/6-WLD/OLA/NHSD mice, which display very slow progression of Wallerian degeneration. Injured nerves of C57BL/6-WLD/OLA/NHSD mice produced significantly lower amounts of IL-6 than did rapidly degenerating nerves of C57/BL/6NHSD mice.