Anesthesia Management Using Remimazolam for Lower Limb Amputation in a Patient With Septic Shock Due to Necrotizing Fasciitis.

We report a case of a patient with necrotizing fasciitis and septic shock caused by streptococcal toxic shock syndrome, who was anesthetized and managed with remimazolam. The patient, a woman in her 40s, was admitted to the ICU with a diagnosis of necrotizing fasciitis of the right lower extremity and septic shock and was scheduled for above-the-knee amputation under general anesthesia. She was anesthetized with remimazolam for sedation and fentanyl and remifentanil for analgesia. Intraoperatively, we were able to maintain hemodynamic stability with similar or only slightly higher doses of circulatory agonists during admission. In the present case, remimazolam, an ultrashort-acting benzodiazepine, was safely used to provide anesthesia to a patient in septic shock due to necrotizing fasciitis, who was receiving high doses of vasopressor agents for cardiovascular support, as it was necessary to select an anesthetic drug that would cause minimal circulatory depression.

The CGA codon decoding through tRNAArg (ICG) supply governed by Tad2/Tad3 in Saccharomyces cerevisiae.

The CGA codon is a rare codon in Saccharomyces cerevisiae and is known to be inefficiently decoded by wobble pairing with Arg-tRNA(ICG). The tRNAArg (ICG) is post-transcriptionally edited from tRNAArg (ACG) by the anticodon first adenosine deamination enzyme Tad2/Tad3 complex. Experimental consecutive CGA codons cause ribosome stalling to result in the reduction of the encoding protein product. In this study, the additional supply of tRNAArg (ACG) genes that produce decoding Arg-tRNA(ICG) promoted the product level from the CGA12-luc reporter, revealing that the product reduction is essentially due to inefficient decoding and deficiency in the tRNA supply. The mature tRNAArg (ICG) and the precursor tRNAArg (ACG) ratios examined for cellular tRNA fraction revealed that the tRNAArg (ICG) ratio is maintained at less than 30% and is responsive to the Tad2/Tad3 expression level.

Human ABCE1 exhibits temperature-dependent heterologous co-functionality in S. cerevisiae.

ABCE1 protein (Rli1 in Saccharomyces cerevisiae) is a unique ribosome recycling factor that is composed of an N-terminal FeS cluster domain and two ATPase domains. Here, we report that heterologous expression of human ABCE1 in S. cerevisiae is unable to complement conditional knockout of ABCE1 (Rli1), at a typical experimental temperature of 30 °C. However, low but significant growth was observed at high temperature, 37 °C. Considering the close interaction of ABCE1 with translation factors and ribosomal components, the observed temperature-dependent complementation may be attributed to heterologous co-functionality of ABCE1 with S. cerevisiae factor(s), and might reflect functional upregulation of human ABCE1 at its functional temperature.

Improving Skin cancer Management with ARTificial Intelligence (SMARTI): protocol for a preintervention/postintervention trial of an artificial intelligence system used as a diagnostic aid for skin cancer management in a specialist dermatology setting.

INTRODUCTION: Convolutional neural networks (CNNs) can diagnose skin cancers with impressive accuracy in experimental settings, however, their performance in the real-world clinical setting, including comparison to teledermatology services, has not been validated in prospective clinical studies. METHODS AND ANALYSIS: Participants will be recruited from dermatology clinics at the Alfred Hospital and Skin Health Institute, Melbourne. Skin lesions will be imaged using a proprietary dermoscopic camera. The artificial intelligence (AI) algorithm, a CNN developed by MoleMap Ltd and Monash eResearch, classifies lesions as benign, malignant or uncertain. This is a preintervention/postintervention study. In the preintervention period, treating doctors are blinded to AI lesion assessment. In the postintervention period, treating doctors review the AI lesion assessment in real time, and have the opportunity to then change their diagnosis and management. Any skin lesions of concern and at least two benign lesions will be selected for imaging. Each participant's lesions will be examined by a registrar, the treating consultant dermatologist and later by a teledermatologist. At the conclusion of the preintervention period, the safety of the AI algorithm will be evaluated in a primary analysis by measuring its sensitivity, specificity and agreement with histopathology where available, or the treating consultant dermatologists' classification. At trial completion, AI classifications will be compared with those of the teledermatologist, registrar, treating dermatologist and histopathology. The impact of the AI algorithm on diagnostic and management decisions will be evaluated by: (1) comparing the initial management decision of the registrar with their AI-assisted decision and (2) comparing the benign to malignant ratio (for lesions biopsied) between the preintervention and postintervention periods. ETHICS AND DISSEMINATION: Human Research Ethics Committee (HREC) approval received from the Alfred Hospital Ethics Committee on 14 February 2019 (HREC/48865/Alfred-2018). Findings from this study will be disseminated through peer-reviewed publications, non-peer reviewed media and conferences. TRIAL REGISTRATION NUMBER: NCT04040114.

Crystal structure of plant vacuolar iron transporter VIT1.

The iron ion is an essential cofactor in several vital enzymatic reactions, such as DNA replication, oxygen transport, and respiratory and photosynthetic electron transfer chains, but its excess accumulation induces oxidative stress in cells. Vacuolar iron transporter 1 (VIT1) is important for iron homeostasis in plants, by transporting cytoplasmic ferrous ions into vacuoles. Modification of the VIT1 gene leads to increased iron content in crops, which could be used for the treatment of human iron deficiency diseases. Furthermore, a VIT1 from the malaria-causing parasite Plasmodium is considered as a potential drug target for malaria. Here we report the crystal structure of VIT1 from rose gum Eucalyptus grandis, which probably functions as a H+-dependent antiporter for Fe2+ and other transition metal ions. VIT1 adopts a novel protein fold forming a dimer of five membrane-spanning domains, with an ion-translocating pathway constituted by the conserved methionine and carboxylate residues at the dimer interface. The second transmembrane helix protrudes from the lipid membrane by about 40 Å and connects to a three-helical bundle, triangular cytoplasmic domain, which binds to the substrate metal ions and stabilizes their soluble form, thus playing an essential role in their transport. These mechanistic insights will provide useful information for the further design of genetically modified crops and the development of anti-malaria drugs.

Misdecoding of rare CGA codon by translation termination factors, eRF1/eRF3, suggests novel class of ribosome rescue pathway in S. cerevisiae.

The CGA arginine codon is a rare codon in Saccharomyces cerevisiae. Thus, full-length mature protein synthesis from reporter genes with internal CGA codon repeats are markedly reduced, and the reporters, instead, produce short-sized polypeptides via an unknown mechanism. Considering the product size and similar properties between CGA sense and UGA stop codons, we hypothesized that eukaryote polypeptide-chain release factor complex eRF1/eRF3 catalyses polypeptide release at CGA repeats. Herein, we performed a series of analyses and report that the CGA codon can be, to a certain extent, decoded as a stop codon in yeast. This also raises an intriguing possibility that translation termination factors eRF1/eRF3 rescue ribosomes stalled at CGA codons, releasing premature polypeptides, and competing with canonical tRNAICG to the CGA codon. Our results suggest an alternative ribosomal rescue pathway in eukaryotes. The present results suggest that misdecoding of low efficient codons may play a novel role in global translation regulation in S. cerevisiae.

Mutations in the G-domain of Ski7 cause specific dysfunction in non-stop decay.

Ski7 functions as a cofactor in both normal mRNA turnover and non-stop mRNA decay (NSD) mRNA surveillance in budding yeast. The N-terminal region of Ski7 (Ski7N) interacts with the ski-complex and the exosome. The C-terminal region of Ski7 (Ski7C) binds guanine nucleotides and shares overall sequence and structural homology with the proteins of the translational GTPase superfamily, especially the tRNA/tRNA-mimic carrier protein subfamilies such as EF1α, eRF3, and Hbs1. Previous reports showed that Ski7N polypeptide functions adequately in vivo, while Ski7C, if any, only slightly. Furthermore, Ski7C does not exhibit GTP-hydrolysing activities under normal conditions. Therefore, the physiological and functional significance of the conserved Ski7C is unclear. Here, we report strong genetic evidence suggesting differential roles for Ski7N and Ski7C in normal and specific mRNA turnover pathways by creating/isolating mutations in both Ski7N and Ski7C conserved motifs using indicator yeast strains. We concluded that Ski7C participates in mRNA surveillance as a regulatory module competitively with the Hbs1/Dom34 complex. Our results provide insights into the molecular regulatory mechanisms underlying mRNA surveillance.

Remifentanil-induced alterations in neutrophil numbers after surgery.

BACKGROUND: Neutrophils are the first line of defense against invasive microorganisms during and after surgery. There is a possibility that different opioid analgesics used during surgery have different effects on the leucocyte count. We retrospectively analyzed the numbers of leucocytes, neutrophils, and lymphocytes just after surgery in patients who received remifentanil-based anesthesia and those who received fentanyl-based anesthesia.In female patients who underwent modified mastectomy or simple mastectomy with resection of a lymph node(s) or with biopsy of a sentinel lymph node(s) between January 2010 and December 2013 (n = 83), propensity score pairwise matching was performed according to the patient's age and procedure, and forty patients (Remifentanil group and Fentanyl group; n = 20 each) were analyzed. FINDINGS: Postoperative numbers of leucocytes and neutrophils were significantly lower in patients who received remifentanil-based anesthesia than in those who received fentanyl-based anesthesia (p = 0.03, p = 0.014; leucocytes and neutrophils, respectively). The increases in the numbers of leucocytes and neutrophils were significantly lower in the patients in the remifentanil group (p = 0.009, p = 0.0046; increase in leucocytes and neutrophils, respectively). CONCLUSIONS: In conclusion, remifentanil-based anesthesia attenuates postoperative leucocyte and neutrophil counts. It is unknown whether this phenomenon indicates the possibility of immunosuppression. Further studies are required.

Structural insights into eRF3 and stop codon recognition by eRF1.

Eukaryotic translation termination is mediated by two interacting release factors, eRF1 and eRF3, which act cooperatively to ensure efficient stop codon recognition and fast polypeptide release. The crystal structures of human and Schizosaccharomyces pombe full-length eRF1 in complex with eRF3 lacking the GTPase domain revealed details of the interaction between these two factors and marked conformational changes in eRF1 that occur upon binding to eRF3, leading eRF1 to resemble a tRNA molecule. Small-angle X-ray scattering analysis of the eRF1/eRF3/GTP complex suggested that eRF1's M domain contacts eRF3's GTPase domain. Consistently, mutation of Arg192, which is predicted to come in close contact with the switch regions of eRF3, revealed its important role for eRF1's stimulatory effect on eRF3's GTPase activity. An ATP molecule used as a crystallization additive was bound in eRF1's putative decoding area. Mutational analysis of the ATP-binding site shed light on the mechanism of stop codon recognition by eRF1.