Clinically relevant mouse models of Charcot-Marie-Tooth type 2S.

Charcot-Marie-Tooth disease is an inherited peripheral neuropathy that is clinically and genetically heterogenous. Mutations in IGHMBP2, a ubiquitously expressed DNA/RNA helicase, have been shown to cause the infantile motor neuron disease spinal muscular atrophy with respiratory distress type 1 (SMARD1), and, more recently, juvenile-onset Charcot-Marie-Tooth disease type 2S (CMT2S). Using CRISPR-cas9 mutagenesis, we developed the first mouse models of CMT2S [p.Glu365del (E365del) and p.Tyr918Cys (Y918C)]. E365del is the first CMT2S mouse model to be discovered and Y918C is the first human CMT2S allele knock-in model. Phenotypic characterization of the homozygous models found progressive peripheral motor and sensory axonal degeneration. Neuromuscular and locomotor assays indicate that both E365del and Y918C mice have motor deficits, while neurobehavioral characterization of sensory function found that E365del mutants have mechanical allodynia. Analysis of femoral motor and sensory nerves identified axonal degeneration, which does not impact nerve conduction velocities in E365del mice, but it does so in the Y918C model. Based on these results, the E365del mutant mouse, and the human allele knock-in, Y918C, represent mouse models with the hallmark phenotypes of CMT2S, which will be critical for understanding the pathogenic mechanisms of IGHMBP2. These mice will complement existing Ighmbp2 alleles modeling SMARD1 to help understand the complex phenotypic and genotypic heterogeneity that is observed in patients with IGHMBP2 variants.

The non-specific lethal complex regulates genes and pathways genetically linked to Parkinson's disease.

Genetic variants conferring risks for Parkinson's disease have been highlighted through genome-wide association studies, yet exploration of their specific disease mechanisms is lacking. Two Parkinson's disease candidate genes, KAT8 and KANSL1, identified through genome-wide studies and a PINK1-mitophagy screen, encode part of the histone acetylating non-specific lethal complex. This complex localizes to the nucleus, where it plays a role in transcriptional activation, and to mitochondria, where it has been suggested to have a role in mitochondrial transcription. In this study, we sought to identify whether the non-specific lethal complex has potential regulatory relationships with other genes associated with Parkinson's disease in human brain. Correlation in the expression of non-specific lethal genes and Parkinson's disease-associated genes was investigated in primary gene co-expression networks using publicly-available transcriptomic data from multiple brain regions (provided by the Genotype-Tissue Expression Consortium and UK Brain Expression Consortium), whilst secondary networks were used to examine cell type specificity. Reverse engineering of gene regulatory networks generated regulons of the complex, which were tested for heritability using stratified linkage disequilibrium score regression. Prioritized gene targets were then validated in vitro using a QuantiGene multiplex assay and publicly-available chromatin immunoprecipitation-sequencing data. Significant clustering of non-specific lethal genes was revealed alongside Parkinson's disease-associated genes in frontal cortex primary co-expression modules, amongst other brain regions. Both primary and secondary co-expression modules containing these genes were enriched for mainly neuronal cell types. Regulons of the complex contained Parkinson's disease-associated genes and were enriched for biological pathways genetically linked to disease. When examined in a neuroblastoma cell line, 41% of prioritized gene targets showed significant changes in mRNA expression following KANSL1 or KAT8 perturbation. KANSL1 and H4K8 chromatin immunoprecipitation-sequencing data demonstrated non-specific lethal complex activity at many of these genes. In conclusion, genes encoding the non-specific lethal complex are highly correlated with and regulate genes associated with Parkinson's disease. Overall, these findings reveal a potentially wider role for this protein complex in regulating genes and pathways implicated in Parkinson's disease.

Novel treatment of acute and acute-on-chronic liver failure: Interleukin-22.

Acute liver failure (ALF) is a life-threatening medical condition, characterized by rapidly progressive hepatic dysfunction, coagulopathy and hepatic encephalopathy in patients without chronic liver disease, while acute-on-chronic liver failure (ACLF) occurs in patients with existing chronic liver disease. ALF and ACLF are often associated with multiple organ failure and a high short-term mortality. In this review, we briefly discuss the causes and pathogenesis of ALF and ACLF, the current options available for the treatment of both deadly maladies and interleukin-22 (IL-22), a novel promising drug that may have great therapeutic potential for ALF and ACLF treatment. IL-22 is a cytokine produced by immune cells but mainly targets epithelial cells including hepatocytes. IL-22 has been shown to protect against organ damage and reduce bacterial infection in many preclinical models and several clinical trials including alcohol-associated hepatitis. The potential application of IL-22 for the treatment of ALF and ACLF is also elaborated.

Investigation of USP30 inhibition to enhance Parkin-mediated mitophagy: tools and approaches.

Mitochondrial dysfunction is implicated in Parkinson disease (PD). Mutations in Parkin, an E3 ubiquitin ligase, can cause juvenile-onset Parkinsonism, probably through impairment of mitophagy. Inhibition of the de-ubiquitinating enzyme USP30 may counter this effect to enhance mitophagy. Using different tools and cellular approaches, we wanted to independently confirm this claimed role for USP30. Pharmacological characterisation of additional tool compounds that selectively inhibit USP30 are reported. The consequence of USP30 inhibition by these compounds, siRNA knockdown and overexpression of dominant-negative USP30 on the mitophagy pathway in different disease-relevant cellular models was explored. Knockdown and inhibition of USP30 showed increased p-Ser65-ubiquitin levels and mitophagy in neuronal cell models. Furthermore, patient-derived fibroblasts carrying pathogenic mutations in Parkin showed reduced p-Ser65-ubiquitin levels compared with wild-type cells, levels that could be restored using either USP30 inhibitor or dominant-negative USP30 expression. Our data provide additional support for USP30 inhibition as a regulator of the mitophagy pathway.

Fibrosis progression rate in a systematic review of placebo-treated nonalcoholic steatohepatitis.

BACKGROUND & AIMS: Liver fibrosis is the critical determinant of liver-related outcomes in persons with nonalcoholic fatty liver disease. The rate that fibrosis develops determines the time taken to reach cirrhosis and consequent clinical outcomes. Estimates of the fibrosis progression rate (FPR) are uncertain having been defined in small observational series that rely largely on nonstandardised repeat biopsy in selected patients. The aim of this study was to evaluate the FPR in placebo-treated participants with nonalcoholic steatohepatitis (NASH) in randomised controlled trials (RCTs). METHODS: Systematic review and meta-analysis of RCTs in NASH with data on fibrosis change extracted. Calculated fibrosis progression rates were pooled in meta-analysis. The pooled estimate was then used to model the proportion of hypothetical cohorts starting with no fibrosis at the age of 30 who develop cirrhosis. RESULTS: A total of 35 trials including 1419 placebo-treated participants who underwent repeat liver biopsy were evaluated. Considering all trials, the overall FPR was 0.00 stages per year, increasing to 0.03 stages per year in both trials at low risk of bias and trials including >50 placebo-treated participants. This estimate was markedly lower than the value derived from previously pooled analyses of observational data. Using a FPR of 0.03 resulted in a substantial reduction in the proportion of patients developing cirrhosis compared with the FPR derived from observational studies (13% vs 28%). CONCLUSIONS: The FPR in placebo-treated participants in RCTs is lower than that described from observational data. Slower fibrosis progression predicts fewer persons with NASH will progress to cirrhosis than previously estimated.

Mitochondrial dysfunction and neurodegenerative proteinopathies: mechanisms and prospects for therapeutic intervention.

Neurodegenerative proteinopathies are a group of pathologically similar, progressive disorders of the nervous system, characterised by structural alterations within and toxic misfolding of susceptible proteins. Oligomerisation of Aß, tau, α-synuclein and TDP-43 leads to a toxin gain- or loss-of-function contributing to the phenotype observed in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and frontotemporal dementia. Misfolded proteins can adversely affect mitochondria, and post-mitotic neurones are especially sensitive to metabolic dysfunction. Misfolded proteins impair mitochondrial dynamics (morphology and trafficking), preventing functional mitochondria reaching the synapse, the primary site of ATP utilisation. Furthermore, a direct association of misfolded proteins with mitochondria may precipitate or augment dysfunctional oxidative phosphorylation and mitochondrial quality control, causing redox dyshomeostasis observed in disease. As such, a significant interest lies in understanding mechanisms of mitochondrial toxicity in neurodegenerative disorders and in dissecting these mechanisms with a view of maintaining mitochondrial homeostasis in disease. Recent advances in understanding mitochondrially controlled cell death pathways and elucidating the mitochondrial permeability pore bioarchitecture are beginning to present new avenues to target neurodegeneration. Novel mitochondrial roles of deubiquitinating enzymes are coming to light and present an opportunity for a new class of proteins to target therapeutically with the aim of promoting mitophagy and the ubiquitin-proteasome system. The brain is enormously metabolically active, placing a large emphasis on maintaining ATP supply. Therefore, identifying mechanisms to sustain mitochondrial function may represent a common intervention point across all proteinopathies.

BET bromodomain ligands: Probing the WPF shelf to improve BRD4 bromodomain affinity and metabolic stability.

Ligands for the bromodomain and extra-terminal domain (BET) family of bromodomains have shown promise as useful therapeutic agents for treating a range of cancers and inflammation. Here we report that our previously developed 3,5-dimethylisoxazole-based BET bromodomain ligand (OXFBD02) inhibits interactions of BRD4(1) with the RelA subunit of NF-κB, in addition to histone H4. This ligand shows a promising profile in a screen of the NCI-60 panel but was rapidly metabolised (t½â€¯= 39.8 min). Structure-guided optimisation of compound properties led to the development of the 3-pyridyl-derived OXFBD04. Molecular dynamics simulations assisted our understanding of the role played by an internal hydrogen bond in altering the affinity of this series of molecules for BRD4(1). OXFBD04 shows improved BRD4(1) affinity (IC50 = 166 nM), optimised physicochemical properties (LE = 0.43; LLE = 5.74; SFI = 5.96), and greater metabolic stability (t½â€¯= 388 min).

Amniotic fluid stem cells improve survival and enhance repair of damaged intestine in necrotising enterocolitis via a COX-2 dependent mechanism.

OBJECTIVE: Necrotising enterocolitis (NEC) remains one of the primary causes of morbidity and mortality in neonates and alternative strategies are needed. Stem cells have become a therapeutic option for other intestinal diseases, which share some features with NEC. We tested the hypothesis that amniotic fluid stem (AFS) cells exerted a beneficial effect in a neonatal rat model of NEC. DESIGN: Rats intraperitoneally injected with AFS cells and their controls (bone marrow mesenchymal stem cells, myoblast) were analysed for survival, behaviour, bowel imaging (MRI scan), histology, bowel absorption and motility, immunofluorescence for AFS cell detection, degree of gut inflammation (myeloperoxidase and malondialdehyde), and enterocyte apoptosis and proliferation. RESULTS: AFS cells integrated in the bowel wall and improved rat survival and clinical conditions, decreased NEC incidence and macroscopic gut damage, improved intestinal function, decreased bowel inflammation, increased enterocyte proliferation and reduced apoptosis. The beneficial effect was achieved via modulation of stromal cells expressing cyclooxygenase 2 in the lamina propria, as shown by survival studies using selective and non-selective cyclooxygenase 2 inhibitors. Interestingly, AFS cells differentially expressed genes of the Wnt/ß-catenin pathway, which regulate intestinal epithelial stem cell function and cell migration and growth factors known to maintain gut epithelial integrity and reduce mucosal injury. CONCLUSIONS: We demonstrated here for the first time that AFS cells injected in an established model of NEC improve survival, clinical status, gut structure and function. Understanding the mechanism of this effect may help us to develop new cellular or pharmacological therapies for infants with NEC.

Increased delivery stride length places greater loads on the ankle joint in elite male cricket fast bowlers.

The purpose of this study was to investigate the effect stride length has on ankle biomechanics of the leading leg with reference to the potential risk of injury in cricket fast bowlers. Ankle joint kinematic and kinetic data were collected from 51 male fast bowlers during the stance phase of the final delivery stride. The bowling cohort comprised national under-19, first class and international-level athletes. Bowlers were placed into either Short, Average or Long groups based on final stride length, allowing statistical differences to be measured. A multivariate analysis of variance with a Bonferroni post-hoc correction (α = 0.05) revealed significant differences between peak plantarflexion angles (Short-Long P = 0.005, Average and Long P = 0.04) and negative joint work (Average-Long P = 0.026). This study highlighted that during fast bowling the ankle joint of the leading leg experiences high forces under wide ranges of movement. As stride length increases, greater amounts of negative work and plantarflexion are experienced. These increases place greater loads on the ankle joint and move the foot into positions that make it more susceptible to injuries such as posterior impingement syndrome.

Lack of nicotinamide mononucleotide adenylyltransferase 2 (Nmnat2): consequences for mouse bladder development and function.

AIMS: To describe the morphological and functional consequences for bladder development and function when nicotinamide mononucleotide adenylyltransferase 2 (Nmnat2) is lacking or reduced. METHODS: The Bloated Bladder (Blad) mouse, lacking Nmnat2, and heterozygotes were utilized for this investigation. Morphology and development of the bladder were studied using immunohistochemistry against urothelial, smooth muscle, and nerve markers. Functional effects were assessed by organ bath experiments and cystometry. RESULTS: Homozygote mutants were malformed and died at birth, whereas heterozygotes survived and morphologically did not differ from wild-type controls. Morphological bladder changes appeared in the Blad mutants as early as embryonic day 15.5 (E15.5) with an extremely distended bladder at E18.5. Staining revealed that all the bladder layers were present and expressed mature markers in all three genotypes. No nerves could be demonstrated by immunohistochemistry in the Blad mutant bladder at E18.5. Organ bath analysis showed that bladders from Blad mutant showed signs of denervation supersensitivity in response to carbachol, and no response to electrical stimulation of nerves at E18.5. Adult heterozygotes, which have a reduced expression of Nmnat2 at E18.5, showed decreased responses to carbachol and electrical stimulation compared to wild-type controls. The latter also retained their ability to empty their bladders, but showed increased micturition pressures compared to controls. CONCLUSIONS: Complete loss of Nmnat2 leads to a mature but distended bladder in utero and is not compatible with survival. Moderate loss of Nmnat2 has no effect on bladder development, survival, and has only modest effects on bladder function later in life.

Running in a minimalist and lightweight shoe is not the same as running barefoot: a biomechanical study.

AIM: The purpose of this study was to determine the changes in running mechanics that occur when highly trained runners run barefoot and in a minimalist shoe, and specifically if running in a minimalist shoe replicates barefoot running. METHODS: Ground reaction force data and kinematics were collected from 22 highly trained runners during overground running while barefoot and in three shod conditions (minimalist shoe, racing flat and the athlete's regular shoe). Three-dimensional net joint moments and subsequent net powers and work were computed using Newton-Euler inverse dynamics. Joint kinematic and kinetic variables were statistically compared between barefoot and shod conditions using a multivariate analysis of variance for repeated measures and standardised mean differences calculated. RESULTS: There were significant differences between barefoot and shod conditions for kinematic and kinetic variables at the knee and ankle, with no differences between shod conditions. Barefoot running demonstrated less knee flexion during midstance, an 11% decrease in the peak internal knee extension and abduction moments and a 24% decrease in negative work done at the knee compared with shod conditions. The ankle demonstrated less dorsiflexion at initial contact, a 14% increase in peak power generation and a 19% increase in the positive work done during barefoot running compared with shod conditions. CONCLUSIONS: Barefoot running was different to all shod conditions. Barefoot running changes the amount of work done at the knee and ankle joints and this may have therapeutic and performance implications for runners.

Left bundle area pacing: Guiding implant depth by ring measurements.

BACKGROUND: Criteria for successful left bundle area pacing (LBAP) are in flux and currently guided by lead tip measurements. Lead ring measurements during LBAP have not been well studied. OBJECTIVE: The purpose of this study was to investigate dynamics in pacing parameters during successful and unsuccessful lead implant attempts. METHODS: SelectSecure 3830 pacing leads (Medtronic, Inc) guided by C315 sheaths for LBAP were placed for standard pacing indications in 73 patients. Retrospective review of procedural, echocardiographic, and standard pacing data were performed. Depth and lead-septal angle of implanted electrodes were determined from fluoroscopy with septal contrast delineation. Depth was graded in 4 categories according to the degree of ring penetration into the septum. Successful implant was defined by the ability to advance the lead deep into the septum and achieve LBAP criteria (ventricular activation time, QRS width/shape). RESULTS: Ring impedance increased stepwise during successful attempts as opposed to unsuccessful attempts (P = .039). A wider lead-septal angle at implant position correlated with higher ring impedance (P = .036), whereas no association was found with tip impedance. Unipolar ring threshold correlated with depth of lead implant (P = .029). Tip impedance measurements at implant position were less predictive of lead depth and did not correlate with septal thickness. CONCLUSION: Ring pacing parameters are more predictive of lead progress than tip measurements. Lead depth and lead-septal angle can be determined from ring impedance measurements. These measurements may provide determination of lead depth and could obviate the need for contrast injection.

USAFSAM Aeromedical Consultation Service Medical Risk Assessment and Airworthiness Matrix.

INTRODUCTION: The 1% rule has long been a standard threshold for aerospace medical risk acceptance, but medical literature has noted multiple shortcomings with this threshold. Previous studies have suggested a risk matrix approach in aeromedical decision-making. General use of risk matrices for risk assessment is already codified in the U.S. Air Force (USAF). Based on this, the USAF School of Aerospace Medicine (USAFSAM) Aeromedical Consultation Service (ACS) generated and evaluated the ACS Medical Risk Assessment and Airworthiness Matrix (AMRAAM).METHODS: The ACS adapted existing USAF standards to build the AMRAAM, gathered expert feedback, and sampled 100 previously adjudicated cases to compare legacy case dispositions to AMRAAM dispositions using polychoric correlation.RESULTS: The AMRAAM disposition showed strong agreement with legacy dispositions (ρ* = 0.9424). One case was discarded as it did not meet inclusion criteria. Of the 99 remaining cases, 88 had perfect agreement between legacy and AMRAAM dispositions. With the AMRAAM, eight cases were less restrictive and three were more restrictive (two due to an erroneous omission in the legacy disposition).DISCUSSION: The AMRAAM produces disposition recommendations that are highly consistent with the legacy approach informed by the 1% rule, with discordant AMRAAM dispositions tending to be more permissive. The USAFSAM AMRAAM allows a more dimensional risk evaluation than the 1% rule, communicates aeromedical risk consistent with nonmedical USAF organizations, and harmonizes aeromedical risk with the level of risk the USAF has defined for all flying systems. The ACS will use the AMRAAM as standard practice in future aeromedical risk assessments.Mayes RS, Keirns CJ, Hicks AG, Menner LD, Lee MS, Wagner JH, Baltzer RL. USAFSAM Aeromedical Consultation Service Medical Risk Assessment and Airworthiness Matrix. Aerosp Med Hum Perform. 2023; 94(7):514-522.

Incidence, risk factors and outcomes of checkpoint inhibitor-induced liver injury: A 10-year real-world retrospective cohort study.

Background & Aims: Checkpoint inhibitors (CPI) account for increasing numbers of drug-induced liver injury (DILI) cases. We aimed to determine the incidence rate and risk factors associated with checkpoint inhibitor-induced liver injury (ChILI). Methods: Prescription event monitoring was performed on all melanoma and renal cancer patients who received CPI at a tertiary centre between 2011 and 2021. ChILI cases were identified using the definitions, grading, and causality assessment methods validated for DILI. We assessed risk factors associated with ChILI in CPI-naive patients using multivariable logistic regression model. Consecutive patients with suspected ChILI from two other tertiary centres were adjudicated and combined for case characterisation and outcomes of ChILI. Results: Out of 432 patients who received CPI over 10 years, ChILI occurred in 38 (8.8%) with an overall incidence rate of 11.5 per 1,000 person-months (95% CI 8.2-15.8). Probability of ChILI was highest in combination therapy (32%) and no new events occurred beyond 135 days of treatment. Risk factor analysis showed that combination therapy, female sex, higher baseline alanine transferase level and lower baseline alkaline phosphatase level were independently associated with higher risk of ChILI. In total, 99 patients were adjudicated to have ChILI from three centres. Although Common Terminology Criteria for Adverse Events classified 20 patients (20.2%) to have 'life-threatening' grade 4 hepatitis, ChILI severity was graded as mild in 45 (45.5%) and moderate in the remaining 54 (54.5%) cases. Conclusions: The real-world risk of ChILI is higher than previously reported. Among patients receiving dual CPI, this risk falls markedly after 4.5 months. As Common Terminology Criteria for Adverse Events overestimates its clinical severity, case-definition, evaluation and management of ChILI should be revised to harmonise care. Impact and implications: Using prescription event monitoring over a 10-year period, the incidence rate of checkpoint inhibitor induced liver injury (ChILI) based on established case definitions for drug-induced liver injury (DILI) is 11.5 per 1,000 person-months. Formal causality assessment identified an alternative cause in 19% of patients with suspected ChILI highlighting the importance of systematic evaluation by clinicians to minimise unnecessary immunosuppression. Intensity of monitoring in patients receiving combination therapy regime after 4.5 months of therapy can be reduced as the risk of new onset ChILI beyond this point is minimal. Current Common Terminology Criteria for Adverse Events (CTCAE) grading overestimates clinical severity of ChILI and hence contributes to avoidable hospitalisation.

Rare disease gene association discovery from burden analysis of the 100,000 Genomes Project data.

To discover rare disease-gene associations, we developed a gene burden analytical framework and applied it to rare, protein-coding variants from whole genome sequencing of 35,008 cases with rare diseases and their family members recruited to the 100,000 Genomes Project (100KGP). Following in silico triaging of the results, 88 novel associations were identified including 38 with existing experimental evidence. We have published the confirmation of one of these associations, hereditary ataxia with UCHL1 , and independent confirmatory evidence has recently been published for four more. We highlight a further seven compelling associations: hypertrophic cardiomyopathy with DYSF and SLC4A3 where both genes show high/specific heart expression and existing associations to skeletal dystrophies or short QT syndrome respectively; monogenic diabetes with UNC13A with a known role in the regulation of ß cells and a mouse model with impaired glucose tolerance; epilepsy with KCNQ1 where a mouse model shows seizures and the existing long QT syndrome association may be linked; early onset Parkinson's disease with RYR1 with existing links to tremor pathophysiology and a mouse model with neurological phenotypes; anterior segment ocular abnormalities associated with POMK showing expression in corneal cells and with a zebrafish model with developmental ocular abnormalities; and cystic kidney disease with COL4A3 showing high renal expression and prior evidence for a digenic or modifying role in renal disease. Confirmation of all 88 associations would lead to potential diagnoses in 456 molecularly undiagnosed cases within the 100KGP, as well as other rare disease patients worldwide, highlighting the clinical impact of a large-scale statistical approach to rare disease gene discovery.

Fetal spine findings on MRI and associated outcomes in children with open neural tube defects.

OBJECTIVE: The purpose of this study is to determine the relationship between abnormal fetal spine findings on MRI and adverse outcomes in children with open neural tube defects. MATERIALS AND METHODS: This was a review of pregnancies complicated by myelomeningocele referred for fetal MRI from 2001 to 2007 and followed postnatally at a spina bifida treatment center. MRI scans were reviewed to determine lesion level (T-L2, L3-4, or L5-S), interpediculate distance (≤ 10 or > 10 mm), vertebral segment span, and presence or absence of covering membrane. Ambulation was assessed in children 3 years old or older. Bladder dysfunction was termed as high-risk if renal damage was present or if urodynamic studies indicated increased risk for renal damage. Statistical analyses included chi-square, Mantel-Haenszel test for trend, and logistic regression. RESULTS: MRI was performed in 36 pregnancies with fetal myelomeningocele at a mean (± SD) of 27 ± 6 weeks, with subsequent delivery at 38 ± 1 week. Outcomes were assessed at 3.2 years (range, 2.4-5.1 years), and 23 children were 3 years old or older. Higher lesion level was associated with dysphagia: T-L2, 50%; L3-4, 45%; and L5-S, 13% (p < 0.05). The absence of covering membrane was associated with scoliosis (36% vs 0% with membrane present) and with high-risk bladder dysfunction (71% vs 36%; both p < 0.05). Higher lesion level, larger segment span, and interpediculate distance greater than 10 mm were associated with full-time wheelchair use (all p < 0.05). CONCLUSION: In fetuses with myelomeningoceles, higher and larger lesions on MRI were significantly associated with full-time wheelchair use. High lesion level was associated with dysphagia. The absence of a covering membrane was associated with scoliosis and high-risk bladder dysfunction.

Implementation, adherence, and results of systematic SARS-CoV-2 testing for asymptomatic patients treated at a tertiary care regional radiation oncology network.

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus is a current pandemic. We initiated a program of systematic SARS-CoV-2 polymerase chain reaction (PCR) testing in all asymptomatic patients receiving radiotherapy (RT) at a large radiation oncology network in the Charlotte, NC metropolitan region and report adherence and results of the testing program. METHODS: Patients undergoing simulation for RT between May 18, 2020 and July 10, 2020 within the Levine Cancer Institute radiation oncology network who were asymptomatic for COVID-19 associated symptoms, without previous positive SARS-CoV-2 testing, and without recent high-risk contacts were included. PCR testing was performed on nasal cavity or nasopharyngeal swab samples. Testing was performed within 2 weeks of RT start (pre-RT) and at least every 4 weeks during RT for patients with prolonged RT courses (intra-RT). An automated task based process using the oncology electronic medical record (EMR) was developed specifically for this purpose. RESULTS: A total of 604 unique patients were included in the cohort. Details on testing workflow and implementation are described herein. Pre-RT PCR testing was performed in 573 (94.9%) patients, of which 4 (0.7%) were positive. The adherence rate to intra-RT testing overall was 91.6%. Four additional patients (0.7%) tested positive during their RT course, of whom 3 were tested due to symptom development and 1 was asymptomatic and identified via systematic testing. A total of 8 (1.3%) patients tested positive overall. There were no known cases of SARS-CoV-2 transmission from infected patients to clinic staff and/or other patients. CONCLUSIONS: We detailed the workflows used to implement systematic SARS-CoV-2 for asymptomatic patients at a large radiation oncology network. Adherence rates for pre-RT and intra-RT testing were high using this process. This information allowed for appropriate delay in initiating RT, minimizing the occurrence of RT treatment interruptions, and no known cases of transmission from infected patients to clinic staff and/or other patients.

Incidence of new onset metabolic acidosis following enteroplasty for myelomeningocele.

PURPOSE: Extant literature is mixed regarding risk of metabolic acidosis after enteroplasty for myelomeningocele. This study is the first known attempt to describe the pattern of developing metabolic acidosis in a group of children who underwent enteroplasty and served as their own controls. Multiple preoperative and postoperative laboratory measures for each child were obtained for comparison. MATERIALS AND METHODS: This retrospective cohort study allowed participants to serve as their own controls for pre-intervention and post-intervention analysis. The setting was a tertiary, university affiliated, interdisciplinary spina bifida program. All patients followed in the spina bifida program who had undergone ileal or colonic enteroplasty were included for review (total 113). Strict exclusion criteria were preoperatively diagnosed renal insufficiency, preexisting metabolic acidosis consistent with renal tubular acidosis (pH less than 7.35, bicarbonate 20 mmol/l or less) and history of augmentation using gastric or ureteral tissue. Final analysis included 71 children who met inclusion criteria. Children in our spina bifida program periodically undergo routine laboratory evaluation of electrolytes, blood urea nitrogen, creatinine, blood count, and venous blood gases including pH, bicarbonate and partial pressure of carbon dioxide. Primary outcome measures were comparative shifts in blood gases and electrolytes that would confirm the new onset of metabolic acidosis after enteroplasty. Changes in electrolytes and serum creatinine were secondary outcome measures to identify potential markers for postoperative effects. With each child as his/her own control, analysis included paired t tests. RESULTS: No statistically significant differences (p <0.05) were found when comparing laboratory values before and after bladder augmentation, including pH, bicarbonate, partial pressure of carbon dioxide and electrolytes. No child had metabolic acidosis based on the aforementioned criteria. Followup ranged from 1 to 138 months after enteroplasty (mean 46.8). Respiratory compensation was considered in the analysis, and no difference in partial pressure of carbon dioxide following surgery was noted (p = 0.65). CONCLUSIONS: To our knowledge no previous study has examined the matched paired results of before and after development of metabolic acidosis among children (serving as their own controls) with myelomeningocele undergoing ileal or colonic enteroplasty. The negative statistical results in this controlled cohort are clinically significant. If a child with myelomeningocele has metabolic acidosis after enteroplasty, other clinical reasons beyond the effects of surgery warrant careful consideration.

The spectrum of resistance in SR/CR mice: the critical role of chemoattraction in the cancer/leukocyte interaction.

BACKGROUND: Spontaneous regression/complete resistance (SR/CR) mice are a unique colony of mice that possess an inheritable, natural cancer resistance mediated primarily by innate cellular immunity. This resistance is effective against sarcoma 180 (S180) at exceptionally high doses and these mice remain healthy. METHODS: In this study, we challenged SR/CR mice with additional lethal transplantable mouse cancer cell lines to determine their resistance spectrum. The ability of these transplantable cancer cell lines to induce leukocyte infiltration was quantified and the percentage of different populations of responding immune cells was determined using flow cytometry. RESULTS: In comparison to wild type (WT) mice, SR/CR mice showed significantly higher resistance to all cancer cell lines tested. However, SR/CR mice were more sensitive to MethA sarcoma (MethA), B16 melanoma (B16), LL/2 lung carcinoma (LL/2) and J774 lymphoma (J774) than to sarcoma 180 (S180) and EL-4 lymphoma (EL-4). Further mechanistic studies revealed that this lower resistance to MethA and LL/2 was due to the inability of these cancer cells to attract SR/CR leukocytes, leading to tumor cell escape from resistance mechanism. This escape mechanism was overcome by co-injection with S180, which could attract SR/CR leukocytes allowing the mice to resist higher doses of MethA and LL/2. S180-induced cell-free ascites fluid (CFAF) co-injection recapitulated the results obtained with live S180 cells, suggesting that this chemoattraction by cancer cells is mediated by diffusible molecules. We also tested for the first time whether SR/CR mice were able to resist additional cancer cell lines prior to S180 exposure. We found that SR/CR mice had an innate resistance against EL-4 and J774. CONCLUSIONS: Our results suggest that the cancer resistance in SR/CR mice is based on at least two separate processes: leukocyte migration/infiltration to the site of cancer cells and recognition of common surface properties on cancer cells. The infiltration of SR/CR leukocytes was based on both the innate ability of leukocytes to respond to chemotactic signals produced by cancer cells and on whether cancer cells produced these chemotactic signals. We found that some cancer cells could escape from SR/CR resistance because they did not induce infiltration of SR/CR leukocytes. However, if infiltration of leukocytes was induced by co-injection with chemotactic factors, these same cancer cells could be effectively recognized and killed by SR/CR leukocytes.

The Association of Introducing a Faecal Calprotectin Testing Pathway for Suspected Inflammatory Bowel Disease in Primary Care and Time to Diagnosis or Treatment.

BACKGROUND: Primary care faecal calprotectin (FC) was introduced in Leeds in 2014 to distinguish inflammatory bowel disease (IBD) from irritable bowel syndrome and with the hope that it may reduce time to IBD diagnosis and treatment. This study examines the association of FC with referral routes, time to diagnosis, and time to treatment. METHODS: All patients newly referred to IBD clinics in 2013 and 2016 were studied. Data on referral routes and dates, FC, date of first treatment, and proxy outcomes for disease severity were collected. RESULTS: In 248 patients, there were no differences between 2013 and 2016 cohorts regarding baseline data and disease severity. The number of direct referrals to gastroenterology rose from 3% (2013) to 17% (2016), whilst 10% were diagnosed during emergency admissions. Referrals via suspected cancer pathways remained high (38% in 2013, 28% in 2016), whilst many had initial investigations at independent centres (16% in 2013, 24% in 2016). Time from referral to diagnosis was similar between 2013 (0.77 month) and 2016 (1.10 months, p = 0.2). A total of 48 (33.3%) patients had FC checked prior to referral, and 37.5% of these were referred directly to gastroenterology. Time from diagnosis to treatment reduced from 1.37 months (2013) to 0.72 month (2016, p = 0.01). CONCLUSION: Patients present via a multitude of referral pathways, but FC was associated with increased direct referrals to gastroenterology. We found a variation in time to diagnosis and treatment depending on referral routes. Further work is required to ensure patients with suspected IBD get referred to IBD services in a timely manner.