J.R.R. Tolkien\u27s Calendars, or The Saga of Hador The Incompetent

Finds inconsistencies in The Lord of the Rings appendix relating Middle-earth’s calendars to the Gregorian

Songbird organotypic culture as an in vitro model for interrogating sparse sequencing networks

Sparse sequences of neuronal activity are fundamental features of neural circuit computation; however, the underlying homeostatic mechanisms remain poorly understood. To approach these questions, we have developed a method for cellular-resolution imaging in organotypic cultures of the adult zebra finch brain, including portions of the intact song circuit. These in vitro networks can survive for weeks, and display mature neuron morphologies. Neurons within the organotypic slices exhibit a diversity of spontaneous and pharmacologically induced activity that can be easily monitored using the genetically encoded calcium indicator GCaMP6. In this study, we primarily focus on the classic song sequence generator HVC and the surrounding areas. We describe proof of concept experiments including physiological, optical, and pharmacological manipulation of these exposed networks. This method may allow the cellular rules underlying sparse, stereotyped neural sequencing to be examined with new degrees of experimental control

Clinical practice guidelines on hemochromatosis: Asian Pacific Association for the Study of the Liver

Hereditary hemochromatosis is the result of pathogenic variants in multiple genes that can result in increased body iron stores with excess iron deposited in various organs, including the liver, pancreas, and heart. The two most important advances in the field over the past 30 years have been the identification of the HFE gene (and the associated p.Cys282Tyr substitution), and the discovery of the hormone hepcidin, which is inappropriately low in this condition and is the pathophysiological basis of the increased iron absorption. The identification of mutations in the HFE gene and subsequent studies have reshaped diagnostic algorithms resulting in a marked reduction in the need for liver biopsy. The discovery of hepcidin has resulted in many studies that have dramatically improved our understanding of iron metabolism with clear potential therapeutic implications. The variable clinical expression of hemochromatosis has puzzled clinicians and scientists, and our understanding of the factors that influence the phenotype has increased over recent years. Nevertheless, increased clinician and patient awareness, early diagnosis, and therapeutic phlebotomy to restore normal life expectancy are still the cornerstones of management. The classic triad of cirrhosis, diabetes, and skin pigmentation is now uncommon, and many patients are diagnosed with minimal or no symptoms

Human pluripotent stem cell modeling of alveolar type 2 cell dysfunction caused by ABCA3 mutations

Mutations in ATP-binding cassette A3 (ABCA3), a phospholipid transporter critical for surfactant homeostasis in pulmonary alveolar type II epithelial cells (AEC2s), are the most common genetic causes of childhood interstitial lung disease (chILD). Treatments for patients with pathological variants of ABCA3 mutations are limited, in part due to a lack of understanding of disease pathogenesis resulting from an inability to access primary AEC2s from affected children. Here, we report the generation of AEC2s from affected patient induced pluripotent stem cells (iPSCs) carrying homozygous versions of multiple ABCA3 mutations. We generated syngeneic CRISPR/Cas9 gene-corrected and uncorrected iPSCs and ABCA3-mutant knockin ABCA3:GFP fusion reporter lines for in vitro disease modeling. We observed an expected decreased capacity for surfactant secretion in ABCA3-mutant iPSC-derived AEC2s (iAEC2s), but we also found an unexpected epithelial-intrinsic aberrant phenotype in mutant iAEC2s, presenting as diminished progenitor potential, increased NFκB signaling, and the production of pro-inflammatory cytokines. The ABCA3:GFP fusion reporter permitted mutant-specific, quantifiable characterization of lamellar body size and ABCA3 protein trafficking, functional features that are perturbed depending on ABCA3 mutation type. Our disease model provides a platform for understanding ABCA3 mutation-mediated mechanisms of alveolar epithelial cell dysfunction that may trigger chILD pathogenesis

Influence of tobacco use on postoperative opiate analgesia requirements in patients undergoing coronary artery bypass graft surgery

Introduction. The objective of this study was to test the hypothesis that tobacco use status is independently associated with postoperative opioid requirements in patients undergoing coronary artery bypass grafting (CABG) when important demographic variables such as age and gender are taken into account. Methods. A retrospective chart review of patients who underwent CABG surgery over a one year period at Mayo Clinic in Rochester, MN was performed. Tobacco users (N=69) were compared to nonusers (N=345) with regards to opiate requirements and the occurrence of severe pain during the first 48 hours postoperatively. For comparison, all postoperative opiates were converted to oral morphine equivalents (OME). Adjusted analysis for age and gender was also performed. Results. Tobacco users were younger than nonusers (P < 0.001), and a greater proportion of former users were male compared to never users (P = 0.003). Tobacco users had greater mean opiate requirements 401 ± 284 than nonusers 314 ± 240 mg OME, (P = 0.009). However, the association between tobacco use and greater postoperative opiate requirements lost significance after adjustment for age and gender. Tobacco use was not associated with increased risk of the development of severe pain (P = 0.51). Conclusions. Although current tobacco users undergoing CABG surgery utilize more opioid analgesics in the first 48 hours following extubation than nonusers of tobacco, when adjusted for age and gender, tobacco use was not independently associated with differences in postoperative opioid use

Immunization expands B cells specific to HIV-1 V3 glycan in mice and macaques.

Broadly neutralizing monoclonal antibodies protect against infection with HIV-1 in animal models, suggesting that a vaccine that elicits these antibodies would be protective in humans. However, it has not yet been possible to induce adequate serological responses by vaccination. Here, to activate B cells that express precursors of broadly neutralizing antibodies within polyclonal repertoires, we developed an immunogen, RC1, that facilitates the recognition of the variable loop 3 (V3)-glycan patch on the envelope protein of HIV-1. RC1 conceals non-conserved immunodominant regions by the addition of glycans and/or multimerization on virus-like particles. Immunization of mice, rabbits and rhesus macaques with RC1 elicited serological responses that targeted the V3-glycan patch. Antibody cloning and cryo-electron microscopy structures of antibody-envelope complexes confirmed that immunization with RC1 expands clones of B cells that carry the anti-V3-glycan patch antibodies, which resemble precursors of human broadly neutralizing antibodies. Thus, RC1 may be a suitable priming immunogen for sequential vaccination strategies in the context of polyclonal repertoires

CRISPR interference interrogation of COPD GWAS genes reveals the functional significance of desmoplakin in iPSC-derived alveolar epithelial cells

Genome-wide association studies (GWAS) have identified dozens of loci associated with chronic obstructive pulmonary disease (COPD) susceptibility; however, the function of associated genes in the cell type(s) affected in disease remains poorly understood, partly due to a lack of cell models that recapitulate human alveolar biology. Here, we apply CRISPR interference to interrogate the function of nine genes implicated in COPD by GWAS in induced pluripotent stem cell–derived type 2 alveolar epithelial cells (iAT2s). We find that multiple genes implicated by GWAS affect iAT2 function, including differentiation potential, maturation, and/or proliferation. Detailed characterization of the GWAS gene DSP demonstrates that it regulates iAT2 cell-cell junctions, proliferation, mitochondrial function, and response to cigarette smoke–induced injury. Our approach thus elucidates the biological function, as well as disease-relevant consequences of dysfunction, of genes implicated in COPD by GWAS in type 2 alveolar epithelial cells.This work was supported by a CJ Martin Early Career Fellowship from the Australian National Health and Medical Research Council awarded to R.B.W.; NIH grant F30HL147426 awarded to K.M.A.; NIH grants U01TR001810, R01DK101501, and R01DK117940 awarded to A.A.W.; NIH grants R01HL135142, R01HL137927, and R01HL147148 awarded to M.H.C.; and NIH grants R01HL127200 and R01HL148667 awarded to X.Z