Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

The cause and consequence of fiber cell compaction in the vertebrate lens

Fiber cells of the ocular lens are arranged in a series of concentric shells. New growth shells are added continuously to the lens surface and, as a consequence, the preexisting shells are buried. To focus light, the refractive index of the lens cytoplasm must exceed that of the surrounding aqueous and vitreous humors, and to that end, lens cells synthesize high concentrations of soluble proteins, the crystallins. To correct for spherical aberration, it is necessary that the crystallin concentration varies from shell-to-shell, such that cellular protein content is greatest in the center of the lens. The radial variation in protein content underlies the critical gradient index (GRIN) structure of the lens. Only the outermost shells of lens fibers contain the cellular machinery necessary for protein synthesis. It is likely, therefore, that the GRIN (which spans the synthetically inactive, organelle-free zone of the lens) does not result from increased levels of protein synthesis in the core of the lens but is instead generated through loss of volume by inner fiber cells. Because volume is lost primarily in the form of cell water, the residual proteins in the central lens fibers can be concentrated to levels of >500 mg/ml. In this short review, we describe the process of fiber cell compaction, its relationship to lens growth and GRIN formation, and offer some thoughts on the likely nature of the underlying mechanism

Peptide analysis by capillary (zone) electrophoresis

In this review various aspects concerning the application of capillary (zone) electrophoresis for peptide analysis will be critically examined. First, the basic instrumental requirements of CE apparatus and the strategies employed to enhance sensitivity in the analysis of underivatized sample are described. Multidimensional separative techniques of complex peptide mixtures that use CE as final step and the coupling of CE with mass spectrometry are subsequently discussed. A theoretical section describes the relationships existing between peptide mobility and the pH of the separation buffer. These relationships evidence that proton dissociation constants and Stokes radius at different protonation stages can be calculated by measuring the electrophoretic mobility at different pH values. Investigation of peptide mobility dependence on pH allows us to establish the optimum conditions, in terms of resolution, for peptide separation. Subsequently, a critical discussion about semiempirical models predicting peptide mobility as a function of chemico-physical peptide properties is presented. A. section is devoted to the description of principles of peptide affinity capillary electrophoresis, underlining the similarity with peptide-proton interaction. CE separations performed in aquo-organic solvents are also critically discussed, showing the good performance obtained by using water-2,2,2-trifluoroethanol solutions. Finally, selected CE applications far the determination of peptide chemico-physical properties and conventional analysis, like peptide mapping, are reported. (C) 1997 Elsevier Science B.V

Age-related compaction of lens fibers affects the structure and optical properties of rabbit lenses

<p>Abstract</p> <p>Background</p> <p>The goal of this investigation was to correlate particular age-related structural changes (compaction) to the amount of scatter in rabbit lenses and to determine if significant fiber compaction occurred in the nuclear and inner cortical regions.</p> <p>Methods</p> <p>New Zealand White rabbits at 16–20 months old (adult; n = 10) and at 3.5–4 years old (aged; n = 10) were utilized for this study. Immediately after euthanising, scatter was assessed in fresh lenses by low power helium-neon laser scan analysis. Scatter data was analyzed both for whole lenses and regionally, to facilitate correlation with morphometric data. After functional analysis, lenses were fixed and processed for scanning electron microcopy (SEM; right eyes) and light microscopy (LM; left eyes). Morphometric analysis of SEM images was utilized to evaluate compaction of nuclear fibers. Similarly, measurements from LM images were used to assess compaction of inner cortical fibers.</p> <p>Results</p> <p>Scatter was significantly greater in aged lenses as compared to adult lenses in all regions analyzed, however the difference in the mean was slightly more pronounced in the inner cortical region. The anterior and posterior elliptical angles at 1 mm (inner fetal nucleus) were significantly decreased in aged vs. adult lenses (anterior, p = 0.040; posterior, p = 0.036). However, the average elliptical angles at 2.5 mm (outer fetal nucleus) were not significantly different in adult and aged lenses since all lenses examined had comparable angles to inner fetal fibers of aged lenses, i.e. they were all compacted. In cortical fibers, measures of average cross-sectional fiber area were significantly different at diameters of both 6 and 7 mm as a function of age (p = 0.011 and p = 0.005, respectively). Accordingly, the estimated fiber volume was significantly decreased in aged as compared to adult lenses at both 6 mm diameter (p = 0.016) and 7 mm diameter (p = 0.010).</p> <p>Conclusion</p> <p>Morphometric data indicates that inner cortical fibers undergo a greater degree of age-related compaction than nuclear fibers. Increased scatter appears to be only tentatively correlated with regions of fiber compaction, suggesting that it is simply one of an array of factors that contribute to the overall decreased transparency in aged rabbit lenses.</p

An external matrix assisted laser desorption ionization source for flexible FT-ICR mass spectrometry imaging with internal calibration on adjacent samples

We describe the construction and application of a new MALDI source for FT-ICR mass spectrometry imaging. The source includes a translational X-Y positioning stage with a 10×10 cm range of motion for analysis of large sample areas, a quadrupole for mass selection, and an external octopole ion trap with electrodes for the application of an axial potential gradient for controlled ion ejection. An off-line LC MALDI MS/MS run demonstrates the utility of the new source for data- and position-dependent experiments. A FT-ICR MS imaging experiment of a coronal rat brain section yields ∼200 unique peaks from m/z 400-1100 with corresponding mass-selected images. Mass spectra from every pixel are internally calibrated with respect to polymer calibrants collected from an adjacent slide