Apical bulkheads accumulate as adaptive response to impaired bile flow in liver disease

Hepatocytes form bile canaliculi that dynamically respond to the signalling activity of bile acids and bile flow. Little is known about their responses to intraluminal pressure. During embryonic development, hepatocytes assemble apical bulkheads that increase the canalicular resistance to intraluminal pressure. Here, we investigate whether they also protect bile canaliculi against elevated pressure upon impaired bile flow in adult liver. Apical bulkheads accumulate upon bile flow obstruction in mouse models and patients with primary sclerosing cholangitis (PSC). Their loss under these conditions leads to abnormally dilated canaliculi, resembling liver cell rosettes described in other hepatic diseases. 3D reconstruction reveals that these structures are sections of cysts and tubes formed by hepatocytes. Mathematical modelling establishes that they positively correlate with canalicular pressure and occur in early PSC stages. Using primary hepatocytes and 3D organoids, we demonstrate that excessive canalicular pressure causes the loss of apical bulkheads and formation of rosettes. Our results suggest that apical bulkheads are a protective mechanism of hepatocytes against impaired bile flow, highlighting the role of canalicular pressure in liver diseases.

Prenatal diagnosis of Myhre syndrome with a heterozygous pathogenic variant in SMAD4 gene presented with thick nuchal translucency and cardiac abnormalities

Prenatal testing was performed in a 39-year-old Chinese pregnant woman referred for increased nuchal translucency measuring 5.7 mm. Non-invasive prenatal testing and SNP array study on amniotic fluid samples were normal. Whole exome sequencing (WES) was initiated further as the fetus had pericardial effusion of 1.2 mm, thickened myocardium over the right ventricular lateral wall and aberrant right subclavian artery. A detailed fetal echocardiogram also revealed persistent left superior vena cava and dilated coronary sinus at 20 weeks. From whole exome sequencing of the trio, a de novo heterozygous variant NM_005359.5(SMAD4): c.1499T>C (p.Ile500Thr) was detected. This pathogenic variant has been reported in the postnatal case cohort of Myhre syndrome. This condition is characterized by facial dysmorphism, intellectual disability, hearing loss, skeletal abnormalities and potential life threatening respiratory or cardiovascular manifestations. Termination of pregnancy was performed at 23 weeks. Small chins, pre-axial polydactyly, brachydactyly and clinodactyly were noted in the abortus. Ultrasound findings of increased nuchal translucency, thickened myocardium and pericardial effusion prompted further genetic evaluation for the prenatal diagnosis of Myhre syndrome by whole exome sequencing.

A randomized controlled clinical evaluation of desensitization efficacy of a newly developed toothpaste with highly stabilized SnF₂

PURPOSE

To assess the relief of dentin hypersensitivity of the new toothpaste with stabilized stannous fluoride (SnF₂) versus a marketed standard fluoride toothpaste as a negative control and a marketed anhydrous SnF₂ toothpaste as a positive control.

METHODS

This was a single-centered, randomized, controlled, double blind, clinical trial. 96 participants with hypersensitivity were enrolled in this 4-week clinical study. Electrical stimulation and evaporative air tests were performed to evaluate the desensitization efficacy. Clinical assessments were made at baseline, and after 3 days, 1 week, 2 weeks and 4 weeks of twice-daily brushing. Additionally, the influence of Sn² ⁺ species on desensitization was evaluated using bovine dentin specimens treated with toothpaste.

RESULTS

All 96 enrolled participants were randomized. 96 participants completed all evaluations. Participants had an average age (SD) of 47.0 (10.5) years; 45% of participants were female. Both SnF₂ toothpastes showed superior desensitization efficacy compared to the negative control toothpaste, the conventional sodium monofluorophosphate (SMFP) toothpaste, after a week. The new stabilized SnF₂ toothpaste demonstrated improved electrical stimulation benefits compared to the negative control toothpaste, with increases of 15.1% after 3 days, 34.2% after 1 week, 66.3% after 2 weeks, and 111.6% after 4 weeks. Additionally, it showed relative verbal evaluation scale (VES) benefits of 14.2% after 3 days, 37.6% after 1 week, 28.9% after 2 weeks, and 37.4% after 4 weeks. The stabilized SnF₂ toothpaste exhibited desensitization properties comparable to those of a commercial anhydrous SnF₂ toothpaste, which typically produces undesirable side effects in the mouth. Toothpastes containing 0.454 % SnF₂ exhibited perfect occlusion of dentin tubules.

CLINICAL SIGNIFICANCE

The stabilized 0.454% SnF₂ toothpaste exhibited significantly greater dentin hypersensitivity relief within only a week and comparable property to commercial anhydrous SnF₂ toothpaste.

Proximal Ultrasound-Guided Posterior Tibial Nerve Block for the Removal of Calcaneal Hardware

The anesthetic technique for calcaneal surgery has been reported to include peripheral nerve blocks, such as a sciatic block in the popliteal fossa, followed by intraoperative sedation. Sciatic nerve blocks are associated with limb weakness and fall risk. We present a case of a patient presenting for outpatient calcaneal surgery. The anesthetic plan consisted of a proximal, ultrasound-guided, single-injection selective posterior tibial nerve block followed by intraoperative sedation. The nerve block was performed, surgery concluded, and the patient received six hours of postoperative analgesia. Once the nerve block effects receded, the postoperative pain was managed with only over-the-counter analgesics while the patient was at home. We recommend an ultrasound-guided proximal posterior tibial nerve block for outpatient surgery involving the calcaneus to preserve lower extremity motor strength and provide postoperative analgesia.

Concomitant left atrial appendage closure with left ventricular assist device surgery can reduce ischemic cerebrovascular accidents

Background

It remains unknown if concomitant left atrial appendage closure (LAAC) at the time of left ventricular assist device (LVAD) surgery can reduce ischemic cerebrovascular accidents.

Purpose

The purpose of this study is to assess the impact of LAAC at LVAD surgery on the incidence of ischemic cerebrovascular accidents.

Methods

Between January 2012 and November 2021, 310 patients underwent LVAD surgery with HeartMate II or III. Out of 310 patients, 98 patients (31.6%) underwent concomitant LAAC. The cohort was divided into two groups: patients with LAAC (Group A, n=98) and without LAAC (Group B, n=212). To minimize device bias, LVAD surgery with HeartWare HVAD device was excluded. The ischemic cerebrovascular accident was defined as ischemic stroke, hemorrhagic stroke or transient ischemic attack. We reviewed early and long-term clinical outcomes. The incidence of ischemic cerebrovascular accidents was compared between two groups using the Kaplan-Meier method. We also investigated if LAAC was associated with ischemic cerebrovascular accidents by Cox proportional hazards analysis.

Results

There were no significant differences in baseline characteristics between two groups including age (Group A: 55.0±12.3 years old, Group B: 56.9±14.1 years old, p=0.26), preoperative CHADS2 score (Group A: 2.40±1.1, Group B: 2.58±1.1, p=0.19) and history of atrial fibrillation (Group A: 42.9%, Group B: 42.5%, p=0.95). In-hospital mortality was not significantly different between the two groups (Group A: 7.1%, Group B: 12.3%, p=0.16). In terms of postoperative complications, there were no significant differences between two groups in requiring extracorporeal membrane oxygenation, re-exploration for bleeding and newly required hemodialysis. Median follow up period was 474 days. Thirty-five patients (11.2%) developed ischemic cerebrovascular accidents (5 patients in Group A and 30 patients in Group B). The rate of freedom from ischemic cerebrovascular accidents in Group A (94.1% at 500 days and 94.1% at 1500 days) was significantly higher than that in Group B (88.2% at 500 days and 77.4% at 1500 days; log rank=0.024). In a Cox proportional hazards regression analysis including LAAC, age, history of atrial fibrillation, diabetes mellitus and Heartmate 3 device implantation, LAAC was associated with reducing the incidence of ischemic cerebrovascular accidents (hazard ratio 0.37, 95% CI 0.13–0.89, p=0.02).

Conclusion

Concomitant LAAC at the time of LVAD surgery can reduce ischemic cerebrovascular accidents without increasing perioperative mortality and complications.

Funding Acknowledgement

Type of funding sources: None.

Further delineation of Auriculocondylar syndrome based on 14 novel cases and reassessment of 25 published cases

Auriculocondylar syndrome (ACS) is a rare craniofacial disorder characterized by mandibular hypoplasia and an auricular defect at the junction between the lobe and helix, known as a "Question Mark Ear" (QME). Several additional features, originating from the first and second branchial arches and other tissues, have also been reported. ACS is genetically heterogeneous with autosomal dominant and recessive modes of inheritance. The mutations identified to date are presumed to dysregulate the endothelin 1 signalling pathway. Here we describe 14 novel cases and reassess 25 published cases of ACS through a questionnaire for systematic data collection. All patients harbour mutation(s) in PLCB4, GNAI3 or EDN1. This series of patients contributes to the characterization of additional features occasionally associated with ACS such as respiratory, costal, neurodevelopmental and genital anomalies, and provides management and monitoring recommendations. This article is protected by copyright. All rights reserved.

Metformin is associated with lower hospitalizations, mortality and severe coronavirus infection among elderly medicare minority patients in 8 states in USA

BACKGROUND AND AIMS

Metformin has antiviral and anti-inflammatory effects and several cohort studies have shown that metformin lower mortality in the COVID population in a majority white population. There is no data documenting the effect of metformin taken as an outpatient on COVID-19 related hospitalizations. Our aim was to evaluate if metformin decreases hospitalization and severe COVID-19 among minority Medicare patients who acquired the SARS-CoV2 virus.

METHODS

We conducted a retrospective cohort study including elderly minority Medicare COVID-19 patients across eight states. We collected data from the inpatient and outpatient electronic health records, demographic data, as well as clinical and echocardiographic data. We classified those using metformin as those patients who had a pharmacy claim for metformin and non-metformin users as those who were diabetics and did not use metformin as well as non-diabetic patients. Our primary outcome was hospitalization. Our secondary outcomes were mortality and acute respiratory distress syndrome (ARDS).

RESULTS

We identified 1139 COVID-19 positive patients of whom 392 were metformin users. Metformin users had a higher comorbidity score than non-metformin users (p < 0.01). The adjusted relative hazard (RH) of those hospitalized for metformin users was 0.71; 95% CI 0.52-0.86. The RH of death for metformin users was 0.34; 95% CI 0.19-0.59. The RH of ARDS for metformin users was 0.32; 95% CI 0.22-0.45. Metformin users on 1000 mg daily had lower mortality, but similar hospitalization and ARDS rates when compared to those on 500-850 mg of metformin daily.

CONCLUSIONS

Metformin is associated with lower hospitalization, mortality and ARDS among a minority COVID-19 population. Future randomized trials should confirm this finding and evaluate for a causative effect of the drug preventing disease.

Cost Effective Technique of Shoulder Arthroscopy Without the Use of Epinephrine in Irrigation Solution

Arthroscopic surgery of the shoulder joint and the subacromial space requires adequate visualization to be effectively performed. Visual clarity is essential to perform a safe and successful arthroscopic procedure. The major determinants to provide visualization in the subacromial space and the glenohumeral joint include adequate inflow (dependent on the dimension of the inflow cannula), flow rate versus pressure, pump system versus gravity, the use of electrocautery and radiofrequency devices, blood pressure control and hypotensive anesthesia, and the type of irrigation solution used with or without the use of epinephrine. In 2012, the cost of a 30-mL (30-mg) vial of epinephrine was $6 (adrenalin/epinephrine injection, USP, Par Pharmaceuticals), and approximately 3 to 4 bottles would be used on average for a single shoulder arthroscopy. In 2019, the same 30-mL bottle of epinephrine cost $237, a nearly 40-fold increase. The purpose of our study is to describe the various factors and techniques that can be used to maintain visual clarity in shoulder arthroscopy without the use of epinephrine in the irrigation solution and the cost savings associated without the use of epinephrine.

Prior cardiovascular risk and screening echocardiograms predict hospitalization and severity of coronavirus infection among elderly medicare patients

Background

The COVID-19 pandemic has disproportionally impacted the elderly. In the United States and Europe the mortality rate of elderly patients with COVID-19 is greater than 30%. Our aim is to determine predictors of COVID-19 related hospitalization and severity of disease among elderly Medicare patients in the United States.

Methods

We conducted a retrospective cohort study including elderly Medicare COVID-19 patients across eight states. We collected data from the inpatient and outpatient electronic health record, demographic, clinical and echocardiographic predictors. Our primary outcomes were hospitalization and adult respiratory distress syndrome (ARDS). Our secondary outcome was mortality.

Results

We identified 400 COVID-19 positive patients (incidence 5.2; (95% CI 4.7-5.7) per 1000 patients). The mean age of our patients was 72 ​± ​8, 60% were female, 82% were minorities and had a mean Charlson score of 2.9 ​± ​1.4. Two-hundred and forty-four patients were hospitalized due to COVID-19 (63%) and the mortality rate was 18%; 95% CI 14-22 with 1 patient still in the hospital. Age, socioeconomic status, Charlson score, systolic blood pressure, body mass index, grade 2 or 3 diastolic dysfunction, moderate or severe left ventricular hypertrophy were significant predictors of hospitalization and ARDS (p ​< ​0.05).

Conclusions

Our study reports a lower incidence on a COVID-19 cohort than previously reported. Predictors of poor outcomes included socio-economic, cardiovascular risk and echocardiographic measures. High touch care with early cardiovascular risk factor modification could explain the low risk of events in our population.

Kinetic Modeling of Hyperpolarized Carbon-13 Pyruvate Metabolism in the Human Brain

Kinetic modeling of the in vivo pyruvate-to-lactate conversion is crucial to investigating aberrant cancer metabolism that demonstrates Warburg effect modifications. Non-invasive detection of alterations to metabolic flux might offer prognostic value and improve the monitoring of response to treatment. In this clinical research project, hyperpolarized [1-¹³C] pyruvate was intravenously injected in a total of 10 brain tumor patients to measure its rate of conversion to lactate ( k_PL ) and bicarbonate ( k_PB ) via echo-planar imaging. Our aim was to investigate new methods to provide k_PL and k_PB maps with whole-brain coverage. The approach was data-driven and addressed two main issues: selecting the optimal model for fitting our data and determining an appropriate goodness-of-fit metric. The statistical analysis suggested that an input-less model had the best agreement with the data. It was also found that selecting voxels based on post-fitting error criteria provided improved precision and wider spatial coverage compared to using signal-to-noise cutoffs alone.

Panel-Based Exome Sequencing for Neuromuscular Disorders as a Diagnostic Service

BACKGROUND

Neuromuscular disorders (NMDs) are clinically and genetically heterogeneous. Accurate molecular genetic diagnosis can improve clinical management, provides appropriate genetic counseling and testing of relatives, and allows potential therapeutic trials.

OBJECTIVE

To establish the clinical utility of panel-based whole exome sequencing (WES) in NMDs in a population with children and adults with various neuromuscular symptoms.

METHODS

Clinical exome sequencing, followed by diagnostic interpretation of variants in genes associated with NMDs, was performed in a cohort of 396 patients suspected of having a genetic cause with a variable age of onset, neuromuscular phenotype, and inheritance pattern. Many had previously undergone targeted gene testing without results.

RESULTS

Disease-causing variants were identified in 75/396 patients (19%), with variants in the three COL6-genes (COL6A1, COL6A2 and COL6A3) as the most common cause of the identified muscle disorder, followed by variants in the RYR1 gene. Together, these four genes account for almost 25% of cases in whom a definite genetic cause was identified. Furthermore, likely pathogenic variants and/or variants of uncertain significance were identified in 95 of the patients (24%), in whom functional and/or segregation analysis should be used to confirm or reject the pathogenicity. In 18% of the cases with a disease-causing variant of which we received additional clinical information, we identified a genetic cause in genes of which the associated phenotypes did not match that of the patients. Hence, the advantage of panel-based WES is its unbiased approach.

CONCLUSION

Whole exome sequencing, followed by filtering for NMD genes, offers an unbiased approach for the genetic diagnostics of NMD patients. This approach could be used as a first-tier test in neuromuscular disorders with a high suspicion of a genetic cause. With uncertain results, functional testing and segregation analysis are needed to complete the evidence.

The epileptology of GNB5 encephalopathy

Pathogenic variants in GNB5 cause an autosomal recessive neurodevelopmental disorder with neonatal sinus bradycardia. Seizures or epilepsy occurred in 10 of 22 previously reported cases, including 6 children from one family. We delineate the epileptology of GNB5 encephalopathy. Our nine patients, including five new patients, were from seven families. Epileptic spasms were the most frequent seizure type, occurring in eight of nine patients, and began at a median age of 3 months (2 months to 3 years). Focal seizures preceded spasms in three children, with onset at 7 days, 11 days, and 4 months. One child presented with convulsive status epilepticus at 6 months. Three children had burst suppression on electroencephalography (EEG), three had hypsarrhythmia, and one evolved from burst suppression to hypsarrhythmia. Background slowing was present in all after age 3 years. Magnetic resonance imaging (MRI) showed cerebral atrophy in one child and cerebellar atrophy in another. All nine had abnormal development prior to seizure onset and ultimately had profound impairment without regression. Hypotonia was present in all, with contractures developing in two older patients. All individuals had biallelic pathogenic variants in GNB5, predicted by in silico tools to result in protein truncation and loss-of-function. GNB5 developmental and epileptic encephalopathy is characterized by epileptic spasms, focal seizures, and profound impairment.