Effect of salbutamol on neuromuscular junction function and structure in a mouse model of DOK7 congenital myasthenia.

Congenital myasthenic syndromes (CMS) are characterized by fatigable muscle weakness resulting from impaired neuromuscular transmission. β2-adrenergic agonists are an effective treatment for DOK7-CMS. DOK7 is a component within the AGRN-LRP4-MUSK-DOK7 signalling pathway that is key for the formation and maintenance of the synaptic structure of the neuromuscular junction (NMJ). The precise mechanism of action of β2-adrenergic agonists at the NMJ is not fully understood. In this study, we investigated whether β2-adrenergic agonists improve both neurotransmission and structural integrity of the NMJ in a mouse model of DOK7-CMS. Ex-vivo electrophysiological techniques and microscopy of the NMJ were used to study the effect of salbutamol, a β2-adrenergic agonist, on synaptic structure and function. DOK7-CMS model mice displayed a severe phenotype with reduced weight gain and perinatal lethality. Salbutamol treatment improved weight gain and survival in DOK7 myasthenic mice. Model animals had fewer active NMJs, detectable by endplate recordings, compared with age-matched wild-type littermates. Salbutamol treatment increased the number of detectable NMJs during endplate recording. Correspondingly, model mice had fewer acetylcholine receptor-stained NMJs detected by fluorescent labelling, but following salbutamol treatment an increased number were detectable. The data demonstrate that salbutamol can prolong survival and increase NMJ number in a severe model of DOK7-CMS

Superconductivity and its enhancement under high pressure in “F-free” single crystals of CeOBiS2

“F-free” CeOBiS2 single crystals have successfully grown, thoroughly eliminating a concern about F-contamination by using a high-purity CsCl flux. The obtained crystals have a plate-like shape with a size of 1.0–3.0 mm in the well-developed plane. Single crystal X-ray structural analysis clearly revealed that the CeOBiS2 crystallizes with a space group P4/nmm (with lattice parameters of a = 4.0189 (6) Å, c = 13.573 (2) Å). The bond valence sum estimation and X-ray photoelectron spectroscopy analysis showed that the chemical state of Ce was in the mixed valence of Ce3+ and Ce4+. The single crystals show superconductivity with zero resistivity at ∼1.3 K. This is the first conclusive evidence of superconductivity driven by Ce valence fluctuation in surely non-doped CeOBiS2. The superconducting transition temperature was enhanced up to ∼3.8 K by applying hydrostatic pressure

Citizen science: a new approach to advance ecology, education, and conservation

Citizen science has a long history in the ecological sciences and has made substantial contributions to science, education, and society. Developments in information technology during the last few decades have created new opportunities for citizen science to engage ever larger audiences of volunteers to help address some of ecology’s most pressing issues, such as global environmental change. Using online tools, volunteers can find projects that match their interests and learn the skills and protocols required to develop questions, collect data, submit data, and help process and analyze data online. Citizen science has become increasingly important for its ability to engage large numbers of volunteers to generate observations at scales or resolutions unattainable by individual researchers. As a coupled natural and human approach, citizen science can also help researchers access local knowledge and implement conservation projects that might be impossible otherwise. In Japan, however, the value of citizen science to science and society is still underappreciated. Here we present case studies of citizen science in Japan, the United States, and the United Kingdom, and describe how citizen science is used to tackle key questions in ecology and conservation, including spatial and macro-ecology, management of threatened and invasive species, and monitoring of biodiversity. We also discuss the importance of data quality, volunteer recruitment, program evaluation, and the integration of science and human systems in citizen science projects. Finally, we outline some of the primary challenges facing citizen science and its future.Dr. Janis L. Dickinson was the keynote speaker at the international symposium at the 61th annual meeting of the Ecological Society of Japan. We appreciate the Ministry of Education, Culture, Sports, Science and Technology in Japan for providing grant to Hiromi Kobori (25282044). Tatsuya Amano is financially supported by the European Commission’s Marie Curie International Incoming Fellowship Programme (PIIF-GA-2011- 303221). The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the funding agencies or the Department of the Interior or the US Government.This is the final version of the article. It was first available from Springer via http://dx.doi.org/10.1007/s11284-015-1314-

Iron-induced dissociation of the Aft1p transcriptional regulator from target gene promoters is an initial event in iron-dependent gene suppression.

Aft1p is an iron-responsive transcriptional activator that plays a central role in the regulation of iron metabolism in Saccharomyces cerevisiae. Aft1p is regulated by accelerated nuclear export in the presence of iron, mediated by Msn5p. However, the transcriptional activity of Aft1p is suppressed under iron-replete conditions in the Δmsn5 strain, although Aft1p remains in the nucleus. Aft1p dissociates from its target promoters under iron-replete conditions due to an interaction between Aft1p and the monothiol glutaredoxin Grx3p or Grx4p (Grx3/4p). The binding of Grx3/4p to Aft1p is induced by iron repletion and requires binding of an iron-sulfur cluster to Grx3/4p. The mitochondrial transporter Atm1p, which has been implicated in the export of iron-sulfur clusters and related molecules, is required not only for iron binding to Grx3p but also for dissociation of Aft1p from its target promoters. These results suggest that iron binding to Grx3p (and presumably Grx4p) is a prerequisite for the suppression of Aft1p. Since Atm1p plays crucial roles in the delivery of iron-sulfur clusters from the mitochondria to the cytoplasm and nucleus, these results support the previous observations that the mitochondrial iron-sulfur cluster assembly machinery is involved in cellular iron sensing

Successful recovery without any neurological complication after intraoperative cardiopulmonary resuscitation for an extended period of time in the lateral position: a case report

Abstract No successful resuscitation has ever been reported about intraoperative cardiopulmonary resuscitation (CPR) for an extended period of time in the lateral position. Here we report a case of successful resuscitation without any neurological complication after cardiac arrest due to massive hemorrhage and 25 min of CPR in the lateral position. The patient was a 65-year-old man. During open hemostasis for the postoperative hemorrhage, the patient’s rhythm changed sinus to ventricular fibrillation (VF), followed by asystole. We started CPR immediately with the patient in the left lateral position. Chest compression was performed by two practitioners, one pressing patient’s sternum and the other pressing simultaneously patient’s mid-thoracic spine from his back. During CPR, though the value of end-tidal CO2 (EtCO2) was significantly low (around 5–20 mmHg), the value of systolic arterial pressure was kept about 35–50 mmHg, and diastolic pressure about 20–30 mmHg. After the 25 min of lateral CPR, he achieved the return of spontaneous circulation (ROSC). He was hemodynamically stable after ROSC. He regained his consciousness at the next postoperative day. He was discharged from our hospital on the 60th day of operation without any cardiac and neurological complication. Successful neurological outcome suggests that we may expect satisfactory neurological outcome even in the case of lateral position and prolonged CPR if we perform effective CPR with the feedback of arterial blood pressure and EtCO2 and with the immediate intervention to culprit injuries

The MuSK activator agrin has a separate role essential for postnatal maintenance of neuromuscular synapses.

The motoneural control of skeletal muscle contraction requires the neuromuscular junction (NMJ), a midmuscle synapse between the motor nerve and myotube. The formation and maintenance of NMJs are orchestrated by the muscle-specific receptor tyrosine kinase (MuSK). Motor neuron-derived agrin activates MuSK via binding to MuSK\u27s coreceptor Lrp4, and genetic defects in agrin underlie a congenital myasthenic syndrome (an NMJ disorder). However, MuSK-dependent postsynaptic differentiation of NMJs occurs in the absence of a motor neuron, indicating a need for nerve/agrin-independent MuSK activation. We previously identified the muscle protein Dok-7 as an essential activator of MuSK. Although NMJ formation requires agrin under physiological conditions, it is dispensable for NMJ formation experimentally in the absence of the neurotransmitter acetylcholine, which inhibits postsynaptic specialization. Thus, it was hypothesized that MuSK needs agrin together with Lrp4 and Dok-7 to achieve sufficient activation to surmount inhibition by acetylcholine. Here, we show that forced expression of Dok-7 in muscle enhanced MuSK activation in mice lacking agrin or Lrp4 and restored midmuscle NMJ formation in agrin-deficient mice, but not in Lrp4-deficient mice, probably due to the loss of Lrp4-dependent presynaptic differentiation. However, these NMJs in agrin-deficient mice rapidly disappeared after birth, and postsynaptic specializations emerged ectopically throughout myotubes whereas exogenous Dok-7-mediated MuSK activation was maintained. These findings demonstrate that the MuSK activator agrin plays another role essential for the postnatal maintenance, but not for embryonic formation, of NMJs and also for the postnatal, but not prenatal, midmuscle localization of postsynaptic specializations, providing physiological and pathophysiological insight into NMJ homeostasis. Proc Natl Acad Sci U S A 2014 Nov 18; 111(46):16556-16561