It takes two to tRNAgo.

In this issue of Structure, Sievers et al. gain important insights into the human tRNA guanine transglycosylase QTRT1/2. The study presents a cryo-EM reconstruction of the inhibited human heterodimer in complex with human tRNA, which represents the first snapshot of a eukaryotic TGT in complex with its full-length tRNA substrate.

Modulation of translational decoding by mA modification of mRNA.

N-methyladenosine (mA) is an abundant, dynamic mRNA modification that regulates key steps of cellular mRNA metabolism. mA in the mRNA coding regions inhibits translation elongation. Here, we show how mA modulates decoding in the bacterial translation system using a combination of rapid kinetics, smFRET and single-particle cryo-EM.

The diverse structural modes of tRNA binding and recognition.

tRNAs are short noncoding RNAs responsible for decoding mRNA codon triplets, delivering correct amino acids to the ribosome, and mediating polypeptide chain formation. Due to their key roles during translation, tRNAs have a highly conserved shape and large sets of tRNAs are present in all living organisms. Regardless of sequence variability, all tRNAs fold into a relatively rigid three-dimensional L-shaped structure.

Rhodopsin-bestrophin fusion proteins from unicellular algae form gigantic pentameric ion channels.

Many organisms sense light using rhodopsins, photoreceptive proteins containing a retinal chromophore. Here we report the discovery, structure and biophysical characterization of bestrhodopsins, a microbial rhodopsin subfamily from marine unicellular algae, in which one rhodopsin domain of eight transmembrane helices or, more often, two such domains in tandem, are C-terminally fused to a bestrophin channel. Cryo-EM analysis of a rhodopsin-rhodopsin-bestrophin fusion revealed that it forms a pentameric megacomplex (~700 kDa) with five rhodopsin pseudodimers surrounding the channel in the center.

Preconditioning Stimulus Intensity Alters Paired-Pulse TMS Evoked Potentials.

Motor cortex (M1) paired-pulse TMS (ppTMS) probes excitatory and inhibitory intracortical dynamics by measurement of motor-evoked potentials (MEPs). However, MEPs reflect cortical and spinal excitabilities and therefore cannot isolate cortical function. Concurrent TMS-EEG has the ability to measure cortical function, while limiting peripheral confounds; TMS stimulates M1, whilst EEG acts as the readout: the TMS-evoked potential (TEP).

Comparison between surface electrodes and ultrasound monitoring to measure TMS evoked muscle contraction.

Introduction: Transcranial magnetic stimulation (TMS) is widely used to explore cortical physiology in health and disease. Surface electromyography (sEMG) is appropriate for superficial muscles, but cannot be applied easily to less accessible muscles. Muscle ultrasound (mUS) may provide an elegant solution to this problem, but fundamental questions remain.

[Lithium nephropathy].

Lithium salts are the first-line drug therapy in the treatment of uni- and bipolar disorder since the sixties of the twentieth century. In the mid-70s, the first information about their nephrotoxicity appeared. Lithium salts have a narrow therapeutic index.

[Rapidly progressive ANCA-negative glomerulonephritis in the course of pauci immune microscopic vasculitis with hemolytic anemia probable in the course of Wilson's disease].

Pauci-immune glomerulonephritis, i.e., with no evidence of immune deposits in the blood vessel, is the most prevalent form of rapidly progressive glomerulonephritis (RPGN).

The influence of sodium profiling on blood volume and intradialytic hypotension in patients on maintenance hemodialysis.

An accurate evaluation of water content in the body of hemodialyzed patients seems to be an important problem in chronic dialysotherapy. Acute intradialytic hypotension observed in 20-33% of hemodialysis patients is a very common complication of this kind of renal replacement therapy. The study was performed in 40 uremic patients, treated with hemodialysis at the Nephrology Clinic of the University Hospital in Cracow.

The evaluation of the effectiveness of multiple dose intradermal hepatitis B re-vaccination in hemodialyzed patients not responding to standard method of immunization.

Hepatitis B is a serious epidemiological problem in uremic patients treated with renal replacement therapy. A high proportion of hemodialyzed patients do not respond to the standard method of intramuscular (i.m.

[Use of Cyclosporine A and new immunosuppressive drugs in the therapy of glomerulonephritis].

Multiple clinical trials have been undertaken during last years to assess indications, efficiency and safety of glomerulonephritis treatment with new immunosuppressive drugs as cyclosporine (CsA, Mycophenolate Mophetil (MMF) and Tacrolimus (FK 506). The main indication for cyclosporine is nephrotic syndrome resistance to steroids and cytotoxic agents, steroid-dependent and multi-relapsing cases with serious toxic side effects or with contraindications for steroids and cytotoxic drugs. CsA was administered at the dose of 4-5 mg/kg/day in adults and 5-6 mg/kg/day in children.

[Renal osteodystrophy in dialysis patients as estimated by three-point bone densitometry].

The aim of a study was to estimate the renal osteodystrophy status using bone densitometry in relation to selected biochemical parameters of calcium-phosphate metabolism. The study population consisted of 123 patients with end-stage renal disease, including 24 patients treated with continuous ambulatory peritoneal dialysis (CAPD), aged between 22 and 73 years (mean 49.9 years), on dialysis program for mean period of 14.