A lentiviral toolkit to monitor airway epithelial cell differentiation using bioluminescence.

Basal cells are adult stem cells in the airway epithelium and regenerate differentiated cell populations, including the mucosecretory and ciliated cells that enact mucociliary clearance. Human basal cells can proliferate and produce differentiated epithelium in vitro. However, studies of airway epithelial differentiation mostly rely on immunohistochemical or immunofluorescence-based staining approaches, meaning that a dynamic approach is lacking, and quantitative data is limited. Here, we use a lentiviral reporter gene approach to transduce primary human basal cells with bioluminescence reporter constructs to monitor airway epithelial differentiation longitudinally. We generated three constructs driven by promoter sequences from the TP63, MUC5AC and FOXJ1 genes to quantitatively assess basal cell, mucosecretory cell and ciliated cell abundance, respectively. We validated these constructs by tracking differentiation of basal cells in air-liquid interface and organoid ('bronchosphere') cultures. Transduced cells also responded appropriately to stimulation with interleukin 13 (IL-13; to increase mucosecretory differentiation and mucus production) and IL-6 (to increase ciliated cell differentiation). These constructs represent a new tool for monitoring airway epithelial cell differentiation in primary epithelial and/or induced pluripotent stem cell (iPSC) cell cultures.

Structure and elevator mechanism of the mammalian sodium/proton exchanger NHE9.

Na+ /H+ exchangers (NHEs) are ancient membrane-bound nanomachines that work to regulate intracellular pH, sodium levels and cell volume. NHE activities contribute to the control of the cell cycle, cell proliferation, cell migration and vesicle trafficking. NHE dysfunction has been linked to many diseases, and they are targets of pharmaceutical drugs. Despite their fundamental importance to cell homeostasis and human physiology, structural information for the mammalian NHE was lacking. Here, we report the cryogenic electron microscopy structure of NHE isoform 9 (SLC9A9) from Equus caballus at 3.2 Å resolution, an endosomal isoform highly expressed in the brain and associated with autism spectrum (ASD) and attention deficit hyperactivity (ADHD) disorders. Despite low sequence identity, the NHE9 architecture and ion-binding site are remarkably similar to distantly related bacterial Na+ /H+  antiporters with 13 transmembrane segments. Collectively, we reveal the conserved architecture of the NHE ion-binding site, their elevator-like structural transitions, the functional implications of autism disease mutations and the role of phosphoinositide lipids to promote homodimerization that, together, have important physiological ramifications.

Malaria parasite translocon structure and mechanism of effector export.

The putative Plasmodium translocon of exported proteins (PTEX) is essential for transport of malarial effector proteins across a parasite-encasing vacuolar membrane into host erythrocytes, but the mechanism of this process remains unknown. Here we show that PTEX is a bona fide translocon by determining structures of the PTEX core complex at near-atomic resolution using cryo-electron microscopy. We isolated the endogenous PTEX core complex containing EXP2, PTEX150 and HSP101 from Plasmodium falciparum in the 'engaged' and 'resetting' states of endogenous cargo translocation using epitope tags inserted using the CRISPR-Cas9 system. In the structures, EXP2 and PTEX150 interdigitate to form a static, funnel-shaped pseudo-seven-fold-symmetric protein-conducting channel spanning the vacuolar membrane. The spiral-shaped AAA+ HSP101 hexamer is tethered above this funnel, and undergoes pronounced compaction that allows three of six tyrosine-bearing pore loops lining the HSP101 channel to dissociate from the cargo, resetting the translocon for the next threading cycle. Our work reveals the mechanism of P. falciparum effector export, and will inform structure-based design of drugs targeting this unique translocon.

Patient reported and functional outcome measures after surgical salvage procedures for posttraumatic radiocarpal osteoarthritis - a systematic review.

BACKGROUND: Posttraumatic wrist osteoarthritis is an irreversible and often progressive condition. Many surgical treatments, used in (daily) practice, aim to relieve symptoms like pain and restore function. The aim of this systematic review is to assess the patient reported and functional outcomes of the most common surgical interventions in patients with posttraumatic wrist osteoarthritis. This overview can help clinicians select the best treatment and manage patient's expectations. METHODS: A literature search was performed in Pubmed, Embase and Cochrane for articles published between 1990 and November 2022 according to the PRISMA guidelines. The study protocol has been registered in the PROSPERO database (CRD42017080427). Studies that describe patient reported outcomes (pain and Disability of Arm, Shoulder and Hand (DASH) -score) and functional outcomes (range of motion (ROM) and grip strength) after surgical intervention with a minimal follow-up of 1 year were included. The identified surgical procedures included denervation, proximal row carpectomy, interpositional- and total arthroplasty, and midcarpal-, radiocarpal- and total arthrodesis. The pre-and postoperative outcomes were pooled and presented per salvage procedure. RESULTS: Data from 50 studies was included. Pain score improved after all surgeries except denervation. Flexion/extension decreased after radiocarpal arthrodesis, did not show significant changes after proximal row carpectomy, and improved for all other surgeries. DASH score improved after arthroplasty, proximal row carpectomy and midcarpal arthrodesis. Grip strength improved after interposition arthroplasty and partial arthrodesis. CONCLUSION: Evidence from this review did not support the indication for denervation in this particular patient population. In patients with SLAC/SNAC II, proximal row carpectomy might be favourable to a midcarpal arthrodesis solely based on better FE ROM of the radiocarpal joint after proximal row carpectomy. In terms of radiocarpal mobility, total wrist arthroplasty might be preferred to radiocarpal arthrodesis in patients with osteoarthritis after a distal radius fracture. More uniform measurements of outcomes would improve the understanding of the effect of surgical treatments of the posttraumatic osteoarthritic wrist.

Percutaneous left stellate ganglion block for refractory ventricular tachycardia in structural heart disease: our single-centre experience.

INTRODUCTION: When electrical storm (ES) is amenable to neither antiarrhythmic drugs, nor deep sedation or catheter ablation, autonomic modulation may be considered. We report our experience with percutaneous left stellate ganglion block (PSGB) to temporarily suppress refractory ventricular arrhythmia (VA) in patients with structural heart disease. METHODS: A retrospective analysis was performed at our institution of patients with structural heart disease and an implantable cardioverter defibrillator (ICD) who had undergone PSGB for refractory VA between January 2018 and October 2021. The number of times antitachycardia pacing (ATP) was delivered and the number of ICD shocks/external cardioversions performed in the week before and after PSGB were evaluated. Charts were checked for potential complications. RESULTS: Twelve patients were identified who underwent a combined total of 15 PSGB and 5 surgical left cardiac sympathetic denervation procedures. Mean age was 73 ± 5.8 years and all patients were male. Nine of 12 (75%) had ischaemic cardiomyopathy, with the remainder having non-ischaemic dilated cardiomyopathy. Mean left ventricular ejection fraction was 35% (±â€¯12.2%). Eight of 12 (66.7%) patients were already being treated with both amiodarone and beta-blockers. The reduction in ATP did not reach statistical significance (p = 0.066); however, ICD shocks (p = 0.028) and ATP/shocks combined were significantly reduced (p = 0.04). At our follow-up electrophysiology meetings PSGB was deemed ineffective in 4 of 12 patients (33%). Temporary anisocoria was seen in 2 of 12 (17%) patients, and temporary hypotension and hoarseness were reported in a single patient. DISCUSSION: In this limited series, PSGB showed promise as a method for temporarily stabilising refractory VA and ES in a cohort of male patients with structural heart disease. The side effects observed were mild and temporary.

What Is the Diagnostic Performance of Conventional Radiographs and Clinical Reassessment Compared With HR-pQCT Scaphoid Fracture Diagnosis?

BACKGROUND: Conventional radiographs and clinical reassessment are considered guides in managing clinically suspected scaphoid fractures. This is a unique study as it assessed the value of conventional radiographs and clinical reassessment in a cohort of patients, all of whom underwent additional imaging, regardless of the outcome of conventional radiographs and clinical reassessment. QUESTIONS/PURPOSES: (1) What is the diagnostic performance of conventional radiographs in patients with a clinically suspected scaphoid fracture compared with high-resolution peripheral quantitative CT (HR-pQCT)? (2) What is the diagnostic performance of clinical reassessment in patients with a clinically suspected scaphoid fracture compared with HR-pQCT? (3) What is the diagnostic performance of conventional radiographs and clinical reassessment combined compared with HR-pQCT? METHODS: Between December 2017 and October 2018, 162 patients with a clinically suspected scaphoid fracture presented to the emergency department (ED). Forty-six patients were excluded and another 25 were not willing or able to participate, which resulted in 91 included patients. All patients underwent conventional radiography in the ED and clinical reassessment 7 to 14 days later, together with CT and HR-pQCT. The diagnostic performance characteristics and accuracy of conventional radiographs and clinical reassessment were compared with those of HR-pQCT for the diagnosis of fractures since this was proven to be superior to CT scaphoid fracture detection. The cohort included 45 men and 46 women with a median (IQR) age of 52 years (29 to 67). Twenty-four patients with a median age of 44 years (35 to 65) were diagnosed with a scaphoid fracture on HR-pQCT. RESULTS: When compared with HR-pQCT, conventional radiographs alone had a sensitivity of 67% (95% CI 45% to 84%), specificity of 85% (95% CI 74% to 93%), positive predictive value (PPV) of 62% (95% CI 46% to 75%), negative predictive value (NPV) of 88% (95% CI 80% to 93%), and a positive and negative likelihood ratio (LR) of 4.5 (95% CI 2.4 to 8.5) and 0.4 (95% CI 0.2 to 0.7), respectively. Compared with HR-pQCT, clinical reassessment alone resulted in a sensitivity of 58% (95% CI 37% to 78%), specificity of 42% (95% CI 30% to 54%), PPV of 26% (95% CI 19% to 35%), NPV of 74% (95% CI 62% to 83%), as well as a positive and negative LR of 1.0 (95% CI 0.7 to 1.5) and 1.0 (95% CI 0.6 to 1.7), respectively. Combining clinical examination with conventional radiography produced a sensitivity of 50% (95% CI 29% to 71%), specificity of 91% (95% CI 82% to 97%), PPV of 67% (95% CI 46% to 83%), NPV of 84% (95% CI 77% to 88%), as well as a positive and negative LR of 5.6 (95% CI 2.4 to 13.2) and 0.6 (95% CI 0.4 to 0.8), respectively. CONCLUSION: The accuracy of conventional radiographs (80% compared with HR-pQCT) and clinical reassessment (46% compared with HR-pQCT) indicate that the value of clinical reassessment is limited in diagnosing scaphoid fractures and cannot be considered directive in managing scaphoid fractures. The combination of conventional radiographs and clinical reassessment does not increase the accuracy of these diagnostic tests compared with the accuracy of conventional radiographs alone and is therefore also limited in diagnosing scaphoid fractures. LEVEL OF EVIDENCE: Level II, diagnostic study.

Highlighting membrane protein structure and function: A celebration of the Protein Data Bank.

Biological membranes define the boundaries of cells and compartmentalize the chemical and physical processes required for life. Many biological processes are carried out by proteins embedded in or associated with such membranes. Determination of membrane protein (MP) structures at atomic or near-atomic resolution plays a vital role in elucidating their structural and functional impact in biology. This endeavor has determined 1198 unique MP structures as of early 2021. The value of these structures is expanded greatly by deposition of their three-dimensional (3D) coordinates into the Protein Data Bank (PDB) after the first atomic MP structure was elucidated in 1985. Since then, free access to MP structures facilitates broader and deeper understanding of MPs, which provides crucial new insights into their biological functions. Here we highlight the structural and functional biology of representative MPs and landmarks in the evolution of new technologies, with insights into key developments influenced by the PDB in magnifying their impact.

Cell signaling stabilizes morphogenesis against noise.

Embryonic development involves gene networks, extracellular signaling, cell behaviors (cell division, adhesion, etc.) and mechanical interactions. How should these be coordinated to lead to complex and robust morphologies? To explore this question, we randomly wired genes and cell behaviors into a huge number of networks in EmbryoMaker. EmbryoMaker is a computational model of animal development that simulates how the 3D positions of cells, i.e. morphology, change over time due to such networks. We found that any gene network can lead to complex morphologies if this activates cell behaviors over large regions of the embryo. Importantly, however, for such complex morphologies to be robust to noise, gene networks should include cell signaling that compartmentalizes the embryo into small regions where cell behaviors are regulated differently. If, instead, cell behaviors are equally regulated over large regions, complex but non-robust morphologies arise. We explain how compartmentalization enhances robustness and why it is a general feature of animal development. Our results are consistent with theories proposing that robustness evolved by the co-option of gene networks and extracellular cell signaling in early animal evolution.

Structure of the human ClC-1 chloride channel.

ClC-1 protein channels facilitate rapid passage of chloride ions across cellular membranes, thereby orchestrating skeletal muscle excitability. Malfunction of ClC-1 is associated with myotonia congenita, a disease impairing muscle relaxation. Here, we present the cryo-electron microscopy (cryo-EM) structure of human ClC-1, uncovering an architecture reminiscent of that of bovine ClC-K and CLC transporters. The chloride conducting pathway exhibits distinct features, including a central glutamate residue ("fast gate") known to confer voltage-dependence (a mechanistic feature not present in ClC-K), linked to a somewhat rearranged central tyrosine and a narrower aperture of the pore toward the extracellular vestibule. These characteristics agree with the lower chloride flux of ClC-1 compared with ClC-K and enable us to propose a model for chloride passage in voltage-dependent CLC channels. Comparison of structures derived from protein studied in different experimental conditions supports the notion that pH and adenine nucleotides regulate ClC-1 through interactions between the so-called cystathionine-ß-synthase (CBS) domains and the intracellular vestibule ("slow gating"). The structure also provides a framework for analysis of mutations causing myotonia congenita and reveals a striking correlation between mutated residues and the phenotypic effect on voltage gating, opening avenues for rational design of therapies against ClC-1-related diseases.

Correction: On the evolution and development of morphological complexity: A view from gene regulatory networks.

[This corrects the article DOI: 10.1371/journal.pcbi.1008570.].

On the evolution and development of morphological complexity: A view from gene regulatory networks.

How does morphological complexity evolve? This study suggests that the likelihood of mutations increasing phenotypic complexity becomes smaller when the phenotype itself is complex. In addition, the complexity of the genotype-phenotype map (GPM) also increases with the phenotypic complexity. We show that complex GPMs and the above mutational asymmetry are inevitable consequences of how genes need to be wired in order to build complex and robust phenotypes during development. We randomly wired genes and cell behaviors into networks in EmbryoMaker. EmbryoMaker is a mathematical model of development that can simulate any gene network, all animal cell behaviors (division, adhesion, apoptosis, etc.), cell signaling, cell and tissues biophysics, and the regulation of those behaviors by gene products. Through EmbryoMaker we simulated how each random network regulates development and the resulting morphology (i.e. a specific distribution of cells and gene expression in 3D). This way we obtained a zoo of possible 3D morphologies. Real gene networks are not random, but a random search allows a relatively unbiased exploration of what is needed to develop complex robust morphologies. Compared to the networks leading to simple morphologies, the networks leading to complex morphologies have the following in common: 1) They are rarer; 2) They need to be finely tuned; 3) Mutations in them tend to decrease morphological complexity; 4) They are less robust to noise; and 5) They have more complex GPMs. These results imply that, when complexity evolves, it does so at a progressively decreasing rate over generations. This is because as morphological complexity increases, the likelihood of mutations increasing complexity decreases, morphologies become less robust to noise, and the GPM becomes more complex. We find some properties in common, but also some important differences, with non-developmental GPM models (e.g. RNA, protein and gene networks in single cells).

Topical rapamycin versus betamethasone dipropionate ointment for treating oral erosive lichen planus: a randomized, double-blind, controlled study.

BACKGROUND: Although superpotent topical corticosteroids are the first-line treatment for oral erosive lichen planus (OELP), topical rapamycin was found efficient in a previous case series. OBJECTIVES: To compare the efficacy and safety of topical rapamycin and betamethasone dipropionate ointment for OELP in a randomized, double-blind trial. METHODS: Patients were randomized to receive treatment with betamethasone dipropionate ointment 0.05% in Orabase® or topical rapamycin solution (1 mg/mL) on lesions twice daily for 3 months, followed by 3 months of observation. The primary outcome was clinical remission after 3 months of treatment. Secondary outcomes were clinical remission after 1 and 2 months, reduced oral pain and reduced impact on food intake after 3 months, clinical recurrence after treatment withdrawal, and adverse events. RESULTS: During a 4-year period, 76 patients were randomized and 75 received treatment (rapamycin, n = 39; betamethasone, n = 36). At 3 months, 39.4% of patients with betamethasone and 27.3% with rapamycin showed clinical remission (odds ratio 0.68, 95% CI [0.24; 1.89]; P = 0.46). Rates of remission after 1 and 2 months, reduction in pain and impact on food intake after 3 months, were higher with betamethasone than rapamycin. Recurrence of oral erosions was similar between groups. Adverse events occurred in 43.6% of patients with rapamycin (mostly burning sensation, impaired taste) and 27.8% with betamethasone (mostly oral candidiasis). CONCLUSION: Although the study was limited by insufficient recruitment, we did not find any superiority of topical rapamycin over betamethasone dipropionate ointment for OELP. Given the rapid remission and pain improvement in the betamethasone group, it appears that superpotent topical corticosteroids should remain the first-line treatment for OELP.

Native and Denaturing MS Protein Deconvolution for Biopharma: Monoclonal Antibodies and Antibody-Drug Conjugates to Polydisperse Membrane Proteins and Beyond.

Electrospray ionization mass spectrometry (ESI-MS) is a ubiquitously used analytical method applied across multiple departments in biopharma, ranging from early research discovery to process development. Accurate, efficient, and consistent protein MS spectral deconvolution across multiple instrument and detector platforms (time-of-flight, Orbitrap, Fourier-transform ion cyclotron resonance) is essential. When proteins are ionized during the ESI process, a distribution of consecutive multiply charged ions are observed on the m/z scale, either positive [M + nH]n+ or negative [M - nH]n- depending on the ionization polarity. The manual calculation of the neutral molecular weight (MW) of single proteins measured by ESI-MS is simple; however, algorithmic deconvolution is required for more complex protein mixtures to derive accurate MWs. Multiple deconvolution algorithms have evolved over the past two decades, all of which have their advantages and disadvantages, in terms of speed, user-input parameters (or ideally lack thereof), and whether they perform optimally on proteins analyzed under denatured or native-MS and solution conditions. Herein, we describe the utility of a parsimonious deconvolution algorithm (explaining the observed spectra with a minimum number of masses) to process a wide range of highly diverse biopharma relevant and research grade proteins and complexes (PEG-GCSF; an IgG1k; IgG1- and IgG2-biotin covalent conjugates; the membrane protein complex AqpZ; a highly polydisperse empty MSP1D1 nanodisc and the tetradecameric chaperone protein complex GroEL) analyzed under native-MS, denaturing LC-MS, and positive and negative modes of ionization, using multiple instruments and therefore multiple data formats. The implementation of a comb filter and peak sharpening option is also demonstrated to be highly effective for deconvolution of highly polydisperse and enhanced separation of a low level lysine glycation post-translational modification (+162.1 Da), partially processed heavy chain lysine residues (+128.1 Da), and loss of N-acetylglucosamine (GlcNAc; -203.1 Da).

Pyridyl Radical Cation for C-H Amination of Arenes.

Electron-transfer photocatalysis provides access to the elusive and unprecedented N-pyridyl radical cation from selected N-substituted pyridinium reagents. The resulting C(sp2 )-H functionalization of (hetero)arenes furnishes versatile intermediates for the development of valuable aminated aryl scaffolds. Mechanistic studies that include the first spectroscopic evidence of a spin-trapped N-pyridyl radical adduct implicate SET-triggered, pseudo-mesolytic cleavage of the N-X pyridinium reagents mediated by visible light.

Rapid LC-MS Method for Accurate Molecular Weight Determination of Membrane and Hydrophobic Proteins.

Therapeutic target characterization involves many components, including accurate molecular weight (MW) determination. Knowledge of the accurate MW allows one to detect the presence of post-translational modifications, proteolytic cleavages, and importantly, if the correct construct has been generated and purified. Denaturing liquid chromatography-mass spectrometry (LC-MS) can be an attractive method for obtaining this information. However, membrane protein LC-MS methodology has remained relatively under-explored and under-incorporated in comparison to methods for soluble proteins. Here, systematic investigation of multiple gradients and column chemistries has led to the development of a 5 min denaturing LC-MS method for acquiring membrane protein accurate MW measurements. Conditions were interrogated with membrane proteins, such as GPCRs and ion channels, as well as bispecific antibody constructs of variable sizes with the aim to provide the community with rapid LC-MS methods necessary to obtain chromatographic and accurate MW measurements in a medium- to high-throughput manner. The 5 min method detailed has successfully produced MW measurements for hydrophobic proteins with a wide MW range (17.5 to 105.3 kDa) and provided evidence that some constructs indeed contain unexpected modifications or sequence clipping. This rapid LC-MS method is also capable of baseline separating formylated and nonformylated aquaporinZ membrane protein.

Conserved SMP domains of the ERMES complex bind phospholipids and mediate tether assembly.

Membrane contact sites (MCS) between organelles are proposed as nexuses for the exchange of lipids, small molecules, and other signals crucial to cellular function and homeostasis. Various protein complexes, such as the endoplasmic reticulum-mitochondrial encounter structure (ERMES), function as dynamic molecular tethers between organelles. Here, we report the reconstitution and characterization of subcomplexes formed by the cytoplasm-exposed synaptotagmin-like mitochondrial lipid-binding protein (SMP) domains present in three of the five ERMES subunits--the soluble protein Mdm12, the endoplasmic reticulum (ER)-resident membrane protein Mmm1, and the mitochondrial membrane protein Mdm34. SMP domains are conserved lipid-binding domains found exclusively in proteins at MCS. We show that the SMP domains of Mdm12 and Mmm1 associate into a tight heterotetramer with equimolecular stoichiometry. Our 17-Å-resolution EM structure of the complex reveals an elongated crescent-shaped particle in which two Mdm12 subunits occupy symmetric but distal positions at the opposite ends of a central ER-anchored Mmm1 homodimer. Rigid body fitting of homology models of these SMP domains in the density maps reveals a distinctive extended tubular structure likely traversed by a hydrophobic tunnel. Furthermore, these two SMP domains bind phospholipids and display a strong preference for phosphatidylcholines, a class of phospholipids whose exchange between the ER and mitochondria is essential. Last, we show that the three SMP-containing ERMES subunits form a ternary complex in which Mdm12 bridges Mmm1 to Mdm34. Our findings highlight roles for SMP domains in ERMES assembly and phospholipid binding and suggest a structure-based mechanism for the facilitated transport of phospholipids between organelles.

Radical Trifluoromethoxylation of Arenes Triggered by a Visible-Light-Mediated N-O Bond Redox Fragmentation.

A simple trifluoromethoxylation method enables non-directed functionalization of C-H bonds on a range of substrates, providing access to aryl trifluoromethyl ethers. This light-driven process is distinctly different from conventional procedures and occurs through an OCF3 radical mechanism mediated by a photoredox catalyst, which triggers an N-O bond fragmentation. The pyridinium-based trifluoromethoxylation reagent is bench-stable and provides access to synthetic diversity in lead compounds in an operationally simple manner.

Crystal structure of Mdm12 and combinatorial reconstitution of Mdm12/Mmm1 ERMES complexes for structural studies.

Membrane contact sites between organelles serve as molecular hubs for the exchange of metabolites and signals. In yeast, the Endoplasmic Reticulum - Mitochondrion Encounter Structure (ERMES) tethers these two organelles likely to facilitate the non-vesicular exchange of essential phospholipids. Present in Fungi and Amoebas but not in Metazoans, ERMES is composed of five distinct subunits; among those, Mdm12, Mmm1 and Mdm34 each contain an SMP domain functioning as a lipid transfer module. We previously showed that the SMP domains of Mdm12 and Mmm1 form a hetero-tetramer. Here we describe our strategy to diversify the number of Mdm12/Mmm1 complexes suited for structural studies. We use sequence analysis of orthologues combined to protein engineering of disordered regions to guide the design of protein constructs and expand the repertoire of Mdm12/Mmm1 complexes more likely to crystallize. Using this combinatorial approach we report crystals of Mdm12/Mmm1 ERMES complexes currently diffracting to 4.5 Å resolution and a new structure of Mdm12 solved at 4.1 Å resolution. Our structure reveals a monomeric form of Mdm12 with a conformationally dynamic N-terminal ß-strand; it differs from a previously reported homodimeric structure where the N-terminal ß strands where swapped to promote dimerization. Based on our electron microscopy data, we propose a refined pseudo-atomic model of the Mdm12/Mmm1 complex that agrees with our crystallographic and small-angle X-ray scattering (SAXS) solution data.

Oesophageal involvement in 26 consecutive patients with mucous membrane pemphigoid.

BACKGROUND: Oesophageal involvement of mucous membrane pemphigoid (MMP) has not yet been thoroughly described. OBJECTIVES: To characterize systematically the endoscopic lesions of a series of patients with oesophageal symptoms seen at a referral centre for autoimmune bullous diseases. METHODS: Clinical, endoscopic and immunological findings of consecutively referred patients with MMP with oesophageal involvement, systemic and endoscopic treatments, and follow-up are described. RESULTS: Of 477 consecutive patients with MMP consulting between 2002 and 2012, 26 (5·4%) had symptomatic oesophageal involvement. Dysphagia, observed in 23 (88%) patients, was the most frequent symptom. Oesophageal symptoms could be the first sign of MMP. Patients with oesophageal involvement had a mean of three other involved sites. At initial oesophageal endoscopy, 17 of 26 patients had active lesions (intact bullae, erosions and/or erythema), 15 had stricture(s) and 12 had other cicatricial lesions. Systemic therapy alone achieved oesophageal symptom relief for five patients. Dilatation was combined with systemic therapy for 12 patients and was successful in nine; one perforation occurred. CONCLUSIONS: Symptomatic oesophageal involvement affected 5·4% of patients with MMP. Dermatologists and gastroenterologists should be aware of these mucocutaneous diseases and their oesophageal involvement, as it could lead to earlier diagnosis and better care. Oesophageal dilatation could be a therapeutic option for symptomatic stricture not relieved by optimized systemic therapy alone.

Rare Lateral Dislocation of the First Metatarsophalangeal Joint: A Case Report and Review of the Literature.

Traumatic lateral dislocations of the first metatarsophalangeal (MTP) joint are very rare. A 44-year-old male was referred after a motorcycle to car accident because of an exposed head of the left first metatarsal through a laceration on the medial aspect of the first MTP joint. Radiographs showed a lateral dislocation of the first MTP joint, with concomitant fractures of the neck of the second metatarsal and the base of the third and fourth metatarsal bones. The dislocation was reduced in the emergency department with the patient under conscious sedation after thorough irrigation. At the 1-year postoperative visit, the patient had full painless range of motion of the first and second MTP joints without any complaints. Lateral dislocation of the first MTP joint is an injury usually associated with fracture of the adjacent metatarsals and/or ligamentous injuries. It is easily reducible, with acceptable midterm outcomes.