Immune biomarker evaluation of sequential tyrosine kinase inhibitor and nivolumab monotherapies in renal cell carcinoma: the phase I TRIBE trial

Background

Predictive biomarkers for immune checkpoint blockade in the second-line treatment of metastatic renal cell carcinoma (mRCC) are lacking.

Materials and methods

Patients with histologically confirmed RCC who started nivolumab after at least 4 months of tyrosine kinase inhibitors (TKIs) were recruited for this study. Serial tissue and blood samples were collected for immune biomarker evaluation. The primary endpoint was to determine the association of specific T-cell subsets with clinical outcomes tested using Wilcoxon rank sum for clinical benefit rate (CBR) and log-rank test for progression-free survival (PFS).

Results

Twenty patients were included in this trial with a median age of 64 years and followed-up for a median of 12 months. The median PFS for patients who received TKI was 13.8 months, while for those subsequently treated with nivolumab following TKI therapy, the median PFS was 2.6 months. CBR of nivolumab was 20% with two partial responses. Functionally active programmed cell death protein 1+ CD4+ T cells were enriched in non-responders (q = 0.003) and associated with worse PFS on nivolumab (P = 0.04). Responders showed a significant reduction in the effector CD4+T-cell (TEF) fraction compared to non-responders at 3 months on nivolumab (0.40 versus 0.80, P = 0.0005). CD127+CD4+ T cells were enriched in patients who developed immune-related adverse effects (q = 0.003). Using in-house validated multiplex immunohistochemistry for six markers, we measured tumour-associated immune cell densities in tissue samples. Responders to nivolumab showed a significantly higher mean of immune cell densities in tissue samples compared to non-responders (346 versus 87 cells/mm2, P = 0.04).

Conclusions

In this small study, analysis of tissue-based and peripheral blood immune cell subsets predicted clinical outcomes of nivolumab. Further studies are warranted with larger populations to validate these observations.

Investigating the Role of MK2 in Head and Neck Squamous Cell Carcinoma Growth, Metastasis and STING Pathway Activation

PURPOSE/OBJECTIVE(S)

Our prior work demonstrated that inhibition of MAPKAPK2 (MK2) can enhance radiation (RT)-mediated in vivo head and neck squamous cell carcinoma (HNSCC) tumor control and survival in preclinical immune incompetent models. The cytosolic DNA sensor cyclic GMP-AMP synthetase (cGAS) and its downstream adaptor protein, stimulator of interferon genes (STING), are conserved proteins within the innate immune signaling pathways and are important for mediating host defense against microbial infection and can play a role in anti-cancer immunity. We hypothesized that loss of MK2 enhances radiation-induced cGAS-STING pathway activation leading to improved tumor control and survival.

MATERIALS/METHODS

MK2 shRNA knockdown human (Tu167, CAL27) and MK2 Cas9/CRISPR knockout (KO) syngeneic murine (Ly2, MLM3) HNSCC cell lines were treated with 10 Gy irradiation. Micronuclei were quantitated by DAPI-immunofluorescence (IF). Protein changes in cGAS-STING were evaluated by immunoblot. Inflammatory cytokine production including Type I IFNβ1 were evaluated by RT-qPCR. Ly2 and MLM3 cells were orthotopically or flank engrafted into immune competent mice (Balb/c, C57Bl/6, respectively) for animal tumor control-survival studies. Tumor immune cell infiltrate was examined using FACS and immunohistochemistry. Selected drug studies using the MK2 inhibitor, ATI-450, were performed with RT.

RESULTS

Loss of MK2 in HNSCC (Tu167, CAL27, Ly2, MLM3) treated with RT led to a significant increase in micronuclei formation compared to control cells. MK2-enhanced micronuclei generation following RT could be inhibited with the actin filament polymerization inhibitor, cytochalasin B. RT treatment of MK2 shRNA cells led to increased cGAS and phospho-STING levels compared to either treatment alone. IFNβ1 levels were significantly higher in HNSCC cell lines treated with RT and with MK2 inhibited by an MK2 inhibitor (ATI-450) or genetic reduction compared to either treatment alone. In-vivo implantation of MLM3 cells into C57Bl/6 comparing control vs MK2 KO tumors treated with ±8 Gy RT demonstrated improved mouse survival favoring RT+MK2 KO over RT, MK2 KO or parental (63, 58, 58.5, 35 days, respectively). FACS analysis of MLM3 WT v KO tumors 3 days post RT showed an overall increase in the number of CD3/CD8 T-cells infiltrating into the tumor in all groups except for parental tumors. Further analysis demonstrated that loss of MK2 reversed CD8 T-cell exhaustion and when combined with radiotherapy led to increased CD8 T-cell activation. Furthermore, activated CD4 and CD8 T cells were reduced in WT+RT cells compared to WT tumors whereas no reduction was seen in the KO or KO+RT.

CONCLUSION

HNSCC tumor MK2 inhibition enhances RT-mediated micronuclei formation and subsequent cGAS-STING-IFNβ1 levels. Loss of HNSCC MK2 leads to increased CD4-CD8 T-cell infiltration into the tumor and this effect is enhanced following RT. Targeting tumor MK2 may facilitate improved tumor control.

Concentration and proteolysis of CX3CL1 may regulate the microglial response to CX3CL1

Fractalkine (FKN) is a membrane-bound chemokine that can be cleaved by proteases such as ADAM 10, ADAM 17, and cathepsin S to generate soluble fragments. Studies using different forms of the soluble FKN yield conflicting results in vivo. These observations prompted us to investigate the function and pharmacology of two commonly used isoforms of FKN, a human full-length soluble FKN (sFKN), and a human chemokine domain only FKN (cdFKN). Both are prevalent in the literature and are often assumed to be functionally equivalent. We observed that recombinant sFKN and cdFKN exhibit similar potencies in a cell-based cAMP assay, but binding affinity for CX3CR1 was modestly different. There was a 10-fold difference in potency between sFKN and cdFKN when assessing their ability to stimulate β-arrestin recruitment. Interestingly, high concentrations of FKN, regardless of cleavage variant, were ineffective at reducing pro-inflammatory microglial activation and may induce a pro-inflammatory response. This effect was observed in mouse and rat primary microglial cells as well as microglial cell lines. The inflammatory response was exacerbated in aged microglia, which is known to exhibit age-related inflammatory phenotypes. We observed the same effects in Cx3cr1-/- primary microglia and therefore speculate that an alternative FKN receptor may exist. Collectively, these data provide greater insights into the function and pharmacology of these common FKN reagents, which may clarify conflicting reports and urge greater caution in the selection of FKN peptides for use in in vitro and in vivo studies and the interpretation of results obtained using these differing peptides.

Accumulation of C-terminal cleaved tau is distinctly associated with cognitive deficits, synaptic plasticity impairment, and neurodegeneration in aged mice

C-terminal cleaved tau at D421 (∆D421-tau) accumulates in the brains of Alzheimer's disease (AD) patients. However, it is unclear how tau truncation, an understudied tau post-translational modification, contributes to AD pathology and progression. Utilizing an adeno-associated virus (AAV) gene delivery-based approach, we overexpressed full-length tau (FL-tau) and ∆D421-tau in 4- and 12-month-old mice for 4 months to study the neuropathological impact of accumulation in young adult (8-month) and middle-aged (16-month) mice. Overall, we show that independent of the tau species, age was an important factor facilitating tau phosphorylation, oligomer formation, and deposition into silver-positive tangles. However, mice overexpressing ∆D421-tau exhibited a distinct phosphorylation profile to those overexpressing FL-tau and increased tau oligomerization in the middle-age group. Importantly, overexpression of ∆D421-tau, but not FL-tau in middle-aged mice, resulted in pronounced cognitive impairments and hippocampal long-term potentiation deficits. While both FL-tau and ∆D421-tau induced neuronal loss in mice with age, ∆D421-tau led to significant neuronal loss in the CA3 area of the hippocampus and medial entorhinal cortex compared to FL-tau. Based on our data, we conclude that age increases the susceptibility to neuronal degeneration associated with ΔD421-tau accumulation. Our findings suggest that ΔD421-tau accumulation contributes to synaptic plasticity and cognitive deficits, thus representing a potential target for tau-associated pathologies.

A functional hiPSC-cortical neuron differentiation and maturation model and its application to neurological disorders

The maturation and functional characteristics of human induced pluripotent stem cell (hiPSC)-cortical neurons has not been fully documented. This study developed a phenotypic model of hiPSC-derived cortical neurons, characterized their maturation process, and investigated its application for disease modeling with the integration of multi-electrode array (MEA) technology. Immunocytochemistry analysis indicated early-stage neurons (day 21) were simultaneously positive for both excitatory (vesicular glutamate transporter 1 [VGlut1]) and inhibitory (GABA) markers, while late-stage cultures (day 40) expressed solely VGlut1, indicating a purely excitatory phenotype without containing glial cells. This maturation process was further validated utilizing patch clamp and MEA analysis. Particularly, induced long-term potentiation (LTP) successfully persisted for 1 h in day 40 cultures, but only achieved LTP in the presence of the GABA_A receptor antagonist picrotoxin in day 21 cultures. This system was also applied to epilepsy modeling utilizing bicuculline and its correction utilizing the anti-epileptic drug valproic acid.

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Characterization of human cortical neuronal differentiation to a mature phenotype

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Microelectrode evaluation of development from a mixed to pure excitatory population

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Utilization of defined culture stage to create an epilepsy model

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Manipulation of immaturity with inhibitors for maintaining long-term potentiation

940 Neck of Femur Fracture Management and Outcomes during COVID-19: Overview of the Results from a District General Hospital in Wales

Introduction

The COVID-19 pandemic has delivered significant challenges to the Orthopaedic community. Our study aims to assess the impact of COVID-19 on the management and outcomes of patient’s presenting with Hip Fractures to our DGH.

Method

Retrospective data analysis was performed on a cohort of hip fracture patients who presented to our DGH before the COVID-19 pandemic (23/03/2019 to 05/05/2019) and were compared to those who presented during the COVID-19 pandemic (23/03/2020 to 05/05/2020). Minimum follow up was 30 days postoperatively.

Results

38 patients with hip fractures presented to our unit in the pre-COVID-19 period compared to 27 patients in the COVID-19 period. Total time from presentation to discharge, during COVID-19, demonstrated a 70.23% decrease when compared to the pre-COVID cohort. 30-day Mortality rates were higher in the COVID-19 cohort.

Conclusions

During the COVID-19 pandemic our time to theatre and discharge of hip fractures has seen an improvement, with time to discharge decreasing by 70.23%. Comparison of our mortality rates has seen a fourfold increase likely influenced by the detrimental effects of COVID-19. Further work and larger numbers are required to see the true impact of COVID-19 on the management and outcomes of hip fractures in our DGH.

Myeloid Arginase 1 Insufficiency Exacerbates Amyloid-β Associated Neurodegenerative Pathways and Glial Signatures in a Mouse Model of Alzheimer's Disease: A Targeted Transcriptome Analysis

Brain myeloid cells, include infiltrating macrophages and resident microglia, play an essential role in responding to and inducing neurodegenerative diseases, such as Alzheimer's disease (AD). Genome-wide association studies (GWAS) implicate many AD casual and risk genes enriched in brain myeloid cells. Coordinated arginine metabolism through arginase 1 (Arg1) is critical for brain myeloid cells to perform biological functions, whereas dysregulated arginine metabolism disrupts them. Altered arginine metabolism is proposed as a new biomarker pathway for AD. We previously reported Arg1 deficiency in myeloid biased cells using lysozyme M (LysM) promoter-driven deletion worsened amyloidosis-related neuropathology and behavioral impairment. However, it remains unclear how Arg1 deficiency in these cells impacts the whole brain to promote amyloidosis. Herein, we aim to determine how Arg1 deficiency driven by LysM restriction during amyloidosis affects fundamental neurodegenerative pathways at the transcriptome level. By applying several bioinformatic tools and analyses, we found that amyloid-β (Aβ) stimulated transcriptomic signatures in autophagy-related pathways and myeloid cells' inflammatory response. At the same time, myeloid Arg1 deficiency during amyloidosis promoted gene signatures of lipid metabolism, myelination, and migration of myeloid cells. Focusing on Aβ associated glial transcriptomic signatures, we found myeloid Arg1 deficiency up-regulated glial gene transcripts that positively correlated with Aβ plaque burden. We also observed that Aβ preferentially activated disease-associated microglial signatures to increase phagocytic response, whereas myeloid Arg1 deficiency selectively promoted homeostatic microglial signature that is non-phagocytic. These transcriptomic findings suggest a critical role for proper Arg1 function during normal and pathological challenges associated with amyloidosis. Furthermore, understanding pathways that govern Arg1 metabolism may provide new therapeutic opportunities to rebalance immune function and improve microglia/macrophage fitness.

Effects of aging and life-long moderate calorie restriction on IL-15 signaling in the rat white adipose tissue

OBJECTIVE

Phosphorylation of insulin receptor substrate (IRS) 1 by tumor necrosis factor alpha (TNF-α) has been implicated as a factor contributing to insulin resistance. Administration of IL-15 reduces adipose tissue deposition in young rats and stimulates secretion of adiponectin, an insulin sensitizing hormone that inhibits the production and activity of TNF-α. We aimed at investigating the effects of age life-long moderate calorie restriction (CR) on IL-15 and TNF-α signaling in rat white adipose tissue (WAT).

MATERIALS AND METHODS

Thirty-six 8-month-old, 18-month-old, and 29-month-old male Fischer344´Brown Norway F1 rats (6 per group) were either fed ad libitum (AL) or calorie restricted by 40%. The serum levels of IL-15 and IL-15 receptor α-chain (IL-15Rα) were increased by CR controls regardless of age. An opposite pattern was detected in WAT. In addition, CR reduced gene expression of TNF-α and cytosolic IRS1 serine phosphorylation in WAT, independently from age.

RESULTS

IL-15 signaling in WAT is increased over the course of aging in AL rats compared with CR rodents. Protein levels of IL-15Rα are greater in WAT of AL than in CR rats independently from age. This adaptation was paralleled by increased IRS1 phosphorylation through TNF-α-mediated insulin resistance. Adiponectin decreased at old age in AL rats, while no changes were evident in CR rats across age groups.

CONCLUSIONS

IL-15 signaling could therefore represent a potential target for interventions to counteract metabolic alterations and the deterioration of body composition during aging.

Arginase 1 Insufficiency Precipitates Amyloid-β Deposition and Hastens Behavioral Impairment in a Mouse Model of Amyloidosis

Alzheimer’s disease (AD) includes several hallmarks comprised of amyloid-β (Aβ) deposition, tau neuropathology, inflammation, and memory impairment. Brain metabolism becomes uncoupled due to aging and other AD risk factors, which ultimately lead to impaired protein clearance and aggregation. Increasing evidence indicates a role of arginine metabolism in AD, where arginases are key enzymes in neurons and glia capable of depleting arginine and producing ornithine and polyamines. However, currently, it remains unknown if the reduction of arginase 1 (Arg1) in myeloid cell impacts amyloidosis. Herein, we produced haploinsufficiency of Arg1 by the hemizygous deletion in myeloid cells using Arg1^fl/fl and LysMcre^Tg/+ mice crossed with APP Tg2576 mice. Our data indicated that Arg1 haploinsufficiency promoted Aβ deposition, exacerbated some behavioral impairment, and decreased components of Ragulator-Rag complex involved in mechanistic target of rapamycin complex 1 (mTORC1) signaling and autophagy. Additionally, Arg1 repression and arginine supplementation both impaired microglial phagocytosis in vitro. These data suggest that proper function of Arg1 and arginine metabolism in myeloid cells remains essential to restrict amyloidosis.

Voltage-gated proton channels exist in the plasma membrane of human oocytes

STUDY QUESTION

Do human oocytes express voltage-gated proton channels?

SUMMARY ANSWER

Human oocytes exhibit voltage-gated proton currents.

WHAT IS KNOWN ALREADY

Voltage-gated proton currents have been reported in human sperm, where they contribute to capacitation and motility. No such studies of human oocytes exist.

STUDY DESIGN, SIZE, DURATION

Voltage-clamp studies were undertaken using entire oocytes and vesicles derived from oocytes and in excised patches of membrane from oocytes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Frozen, thawed human metaphase II oocytes were obtained from material donated to the gamete repository at the Rush Center for Advanced Reproductive Care. Prior to patch clamping, oocytes were warmed and equilibrated. Formation of an electrically tight seal requires exposing bare oolemma. Sections of the zona pellucida (ZP) were removed using a laser, followed by repeated pipetting, to further separate the oocyte from the ZP. Patch-clamp studies were performed using the whole-cell configuration on oocytes or vesicles derived from oocytes, and using inside-out patches of membrane, under conditions optimized to detect voltage-gated proton currents.

MAIN RESULTS AND THE ROLE OF CHANCE

Proton currents are present at significant levels in human oocytes where they exhibit properties similar to those reported in other human cells, as well as those in heterologous expression systems transfected with the HVCN1 gene that codes for the voltage-gated proton channel.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Human oocytes are large cells, which limits our ability to control the intracellular solution. Subtle effects of cryopreservation by vitrification and subsequent warming on properties of HVCN1, the HVCN1 gene product, cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

Possible functions for voltage-gated proton channels in human oocytes may now be contemplated.

STUDY FUNDING/COMPETING INTEREST(S)

NIH R35GM126902 (TED), Bears Care (DM). No competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Immediate and long-term consequences of COVID-19 infections for the development of neurological disease

Increasing evidence suggests that infection with Sars-CoV-2 causes neurological deficits in a substantial proportion of affected patients. While these symptoms arise acutely during the course of infection, less is known about the possible long-term consequences for the brain. Severely affected COVID-19 cases experience high levels of proinflammatory cytokines and acute respiratory dysfunction and often require assisted ventilation. All these factors have been suggested to cause cognitive decline. Pathogenetically, this may result from direct negative effects of the immune reaction, acceleration or aggravation of pre-existing cognitive deficits, or de novo induction of a neurodegenerative disease. This article summarizes the current understanding of neurological symptoms of COVID-19 and hypothesizes that affected patients may be at higher risk of developing cognitive decline after overcoming the primary COVID-19 infection. A structured prospective evaluation should analyze the likelihood, time course, and severity of cognitive impairment following the COVID-19 pandemic.

CCL2 Overexpression in the Brain Promotes Glial Activation and Accelerates Tau Pathology in a Mouse Model of Tauopathy

Innate immune activation is a major contributor to Alzheimer's Disease (AD) pathophysiology, although the mechanisms involved are poorly understood. Chemokine C-C motif ligand (CCL) 2 is produced by neurons and glial cells and is upregulated in the AD brain. Transgene expression of CCL2 in mouse models of amyloidosis produces microglia-induced amyloid β oligomerization, a strong indication of the role of these activation pathways in the amyloidogenic processes of AD. We have previously shown that CCL2 polarizes microglia in wild type mice. However, how CCL2 signaling contributes to tau pathogenesis remains unknown. To address this question, CCL2 was delivered via recombinant adeno-associated virus serotype 9 into both cortex and hippocampus of a mouse model with tau pathology (rTg4510). We report that CCL2 overexpression aggravated tau pathology in rTg4510 as shown by the increase in Gallyas stained neurofibrillary tangles as well as phosphorylated tau-positive inclusions. In addition, biochemical analysis showed a reduction in the levels of detergent-soluble tau species followed by increase in the insoluble fraction, indicating a shift toward larger tau aggregates. Indeed, increased levels of high molecular weight species of phosphorylated tau were found in the mice injected with CCL2. We also report that worsening of tau pathology following CCL2 overexpression was accompanied by a distinct inflammatory response. We report an increase in leukocyte common antigen (CD45) and Cluster of differentiation 68 (CD68) expression in the brain of rTg4510 mice without altering the expression levels of a cell-surface protein Transmembrane Protein 119 (Tmem119) and ionized calcium-binding adaptor molecule 1 (Iba-1) in resident microglia. Furthermore, the analysis of cytokines in brain extract showed a significant increase in interleukin (IL)-6 and CCL3, while CCL5 levels were decreased in CCL2 mice. No changes were observed in IL-1α, IL-1β, TNF-α. IL-4, Vascular endothelial growth factor-VEGF, IL-13 and CCL11. Taken together our data report for the first time that overexpression of CCL2 promotes the increase of pathogenic tau species and is associated with glial neuroinflammatory changes that are deleterious. We propose that these events may contribute to the pathogenesis of Alzheimer's disease and other tauopathies.

Slowing improvements in life expectancy across European Economic Area countries

Background

Life expectancy improvements have slowed down in several European countries since around 2011. The relative contributions from changes in specific conditions (e.g. cancers) and broader risk factors (e.g. smoking or austerity) remain unclear. We aimed to explore the different potential causes in 17 European Economic Area (EEA) countries.

Methods

We compared Global Burden of Disease (GBD) study estimates for life expectancy, years of life lost (YLLs) and population attributable fractions (PAFs) for risk factors, for 2005-2011 and 2011-2017 for 17 EEA countries. Three countries with the largest absolute improvements and three with the smallest were selected for analysis by gender, age, condition and risk factors.

Results

Norway, France and Belgium had the largest improvement in life expectancy (+1.5, +1.2 and +1.2 years respectively) from 2011 to 2017, and Germany, Iceland and the UK the smallest (+0.1, +0.2 and +0.2 years). Life expectancy reduced slightly for women aged over 80 in Germany and UK, men aged over 50 in Germany, and for men in all age groups up to 90 years in Iceland. Norway, France and Belgium saw faster improvements in YLLs from lung cancer and Norway and France for COPD in both men and women, and from self-harm in men, after 2011 than before. PAF for tobacco declined faster after 2011. Germany, Iceland and the UK saw slower improvements in cardiovascular disease and in Germany and the UK lung cancer. In Iceland, YLLs for cancers, self harm, respiratory disease, cirrhosis and dementia all worsened after 2011. PAF for tobacco remained high or declined less after 2011 in all 3 countries. PAFs for alcohol and drug use remained high in Iceland and UK.

Conclusions

Differential changes in major fatal diseases and risk factors help explain national changes in life expectancies, but national differences in data availability may affect results. Further research is needed into the ‘causes of the causes’, such as the 2008 economic crash in Iceland.

Key messages

Differential changes in major fatal diseases and risk factors help explain national changes in life expectancies. Norway, France and Belgium had the largest improvement in life expectancy from 2011 to 2017, and Germany, Iceland and the UK the smallest.

Active immunization with tau epitope in a mouse model of tauopathy induced strong antibody response together with improvement in short memory and pSer396-tau pathology

Abnormal tau hyperphosphorylation and its aggregation into neurofibrillary tangles are a hallmark of tauopathies, neurodegenerative disorders that include Alzheimer's disease (AD). Active and passive Tau-immunotherapy has been proposed as a therapeutic approach to AD with mixed results. One of the limitations of active immunotherapy may be associated with the mediocre immunogenicity of vaccines that are not inducing therapeutically potent titers of antibodies. The aim of this study was to test the efficacy of an anti-tau vaccine, AV-1980R/A composed of N terminal peptide of this molecule fused with an immunogenic MultiTEP platform and formulated in a strong adjuvant, Advax^CpG in a Tg4510 mouse model of tauopathy. Experimental mice were immunized with AV-1980R/A and a control group of mice were injected with adjuvant only. Nontransgenic and tetracycline transactivator (tTA) transgenic littermates were included as baseline controls to contrast with the tau phenotype. Active immunization with AV-1980R/A induced very strong anti-tau humoral immune responses in both nontransgenic and transgenic mice with evidence of IgG in brains of AV-1980R/A vaccinated mice. These experimental animals displayed an improvement in short-term memory during a novel object recognition test. However, impairments in other behavioral tasks were not prevented by AV-1980R/A vaccinations. At the same time, high titers of anti-tau antibodies reduced hyperphosphorylated pSer396 tau but did not lower the level of other phosphorylated tau species in the brains of AV-1980R/A vaccinated mice. These data indicate that active immunotherapy with an N-terminal Tau epitope was only partially effective in improving cognition and reducing pathology in the stringent Tg4510 mouse model of tauopathy.

Surveillance of congenital Zika syndrome in England and Wales: methods and results of laboratory, obstetric and paediatric surveillance

The spread of the Zika virus (ZIKV) in the Americas led to large outbreaks across the region and most of the Southern hemisphere. Of greatest concern were complications following acute infection during pregnancy. At the beginning of the outbreak, the risk to unborn babies and their clinical presentation was unclear. This report describes the methods and results of the UK surveillance response to assess the risk of ZIKV to children born to returning travellers. Established surveillance systems operating within the UK - the paediatric and obstetric surveillance units for rare diseases, and national laboratory monitoring - enabled rapid assessment of this emerging public health threat. A combined total of 11 women experiencing adverse pregnancy outcomes after possible ZIKV exposure were reported by the three surveillance systems; five miscarriages, two intrauterine deaths and four children with clinical presentations potentially associated with ZIKV infection. Sixteen women were diagnosed with ZIKV during pregnancy in the UK. Amongst the offspring of these women, there was unequivocal laboratory evidence of infection in only one child. In the UK, the number and risk of congenital ZIKV infection for travellers returning from ZIKV-affected countries is very small.

Orthopaedic manifestations of pseudoachondroplasia

PURPOSE

In 1959, Maroteaux and Lamy initially designated pseudoachondroplasia as a distinct dysplasia different from achondroplasia the most common form of skeletal dysplasia. Pseudoachondroplasia is caused by a mutation in the collagen oligomeric matrix protein gene (COMP) gene on chromosome 19p13.1-p12 encoding the COMP. The COMP gene mutations result in rendering the articular and growth plate cartilages incapable of withstanding routine biomechanical loads with resultant deformity of the joints. The purpose of the study was to characterize the typical orthopaedic findings in pseudoachondroplasia.

METHODS

The charts and radiographs of 141 patients with pseudoachondroplasia were analyzed. This cohort, to our knowledge, represents the largest group of patients describing the typical orthopaedic manifestations of pseudoachondroplasia.

RESULTS

Patients with pseudoachondroplasia have normal craniofacial appearance with normal intelligence. Short stature is not present at birth and generally appears by two to four years of age. The condition is a form of spondyloepiphyseal dysplasia and the long bones are characterized by dysplastic changes in the epiphysis, metaphysis and vertebral bodies. Radiographically the long bones have altered the appearance and structure of the epiphyses with small irregularly formed or fragmented epiphyses or flattening. The metaphyseal regions of the long bones show flaring, widening or 'trumpeting'. The cervical (89%) and thoracic and lumbar vertebrae show either platyspondyly, ovoid, 'cod-fish' deformity or anterior 'beaking'. Kyphosis (28%), scoliosis (58%) and lumbar lordosis (100%) are commonly seen. The femoral head and acetabulum are severely dysplastic (100%). The knees show either genu valgum (22%), genu varum (56%) or 'windswept' deformity (22%).

CONCLUSION

Most commonly these distortions of the appendicular and the axial skeleton lead to premature arthritis particularly of the hips and often the knees not uncommonly in the 20- to 30-year-old age group.

LEVEL OF EVIDENCE

III.

Enhancing wastewater remediation by drinking water treatment residual-augmented floating treatment wetlands

In this study, the involvement of aluminum-based drinking water treatment residual (DWTR) as substrate in floating treatment wetland (FTW) to enhance its treatment performance was firstly proposed and trialed. A laboratory scale DWTR-FTW fed with synthetic wastewater containing COD, nitrogen (N), phosphorus (P) and mineral salts was operated in three stages of unplanted (1-30 days), planted (31-60 days) and aerated (61-135 days) modes. The results showed that the average removal rates of COD, total nitrogen (TN), total phosphorus (TP) in stage 3 were 88%, 85%, and 90.2%, respectively, indicating the outstanding purification performance of DWTR-FTW in comparison of traditional FTWs. The embedded DWTR enriches the biomass and robustly adsorbs P, while aeration supplies sufficient dissolved oxygen for the microorganism. The results revealed that 7.022 g P was accumulated in DWTR, which is 400 times higher than that in sediment and plants during the experimental period, reflecting that DWTR adsorption is the major P removal pathway in DWTR-FTW. Overall, DWTR-FTW could significantly remove pollutants, especially P, and provide an alternative pathway to enhance purification performance of FTW.

On the Elevated Temperature Thermal Stability of Nanoscale Mn-Ni-Si Precipitates Formed at Lower Temperature in Highly Irradiated Reactor Pressure Vessel Steels

Atom probe tomography (APT) and scanning transmission electron microscopy (STEM) techniques were used to probe the long-time thermal stability of nm-scale Mn-Ni-Si precipitates (MNSPs) formed in intermediate and high Ni reactor pressure vessel steels under high fluence neutron irradiation at ≈320 °C. Post irradiation annealing (PIA) at 425 °C for up to 57 weeks was used to determine if the MNSPs are: (a) non-equilibrium solute clusters formed and sustained by radiation induced segregation (RIS); or, (b) equilibrium G or Γ₂ phases, that precipitate at accelerated rates due to radiation enhanced diffusion (RED). Note the latter is consistent with both thermodynamic models and x-ray diffraction (XRD) measurements. Both the experimental and an independently calibrated cluster dynamics (CD) model results show that the stability of the MNSPs is very sensitive to the alloy Ni and, to a lesser extent, Mn content. Thus, a small fraction of the largest MNSPs in the high Ni steel persist, and begin to coarsen at long times. These results suggest that the MNSPs remain a stable phase, even at 105 °C higher than they formed at, thus are most certainly equilibrium phases at much lower service relevant temperatures of ≈290 °C.

Spermidine/spermine-N1-acetyltransferase ablation impacts tauopathy-induced polyamine stress response

BACKGROUND

Tau stabilizes microtubules; however, in Alzheimer's disease (AD) and tauopathies, tau becomes hyperphosphorylated, aggregates, and results in neuronal death. Our group recently uncovered a unique interaction between polyamine metabolism and tau fate. Polyamines exert an array of physiological effects that support neuronal function and cognitive processing. Specific stimuli can elicit a polyamine stress response (PSR), resulting in altered central polyamine homeostasis. Evidence suggests that elevations in polyamines following a short-term stressor are beneficial; however, persistent stress and subsequent PSR activation may lead to maladaptive polyamine dysregulation, which is observed in AD, and may contribute to neuropathology and disease progression.

METHODS

Male and female mice harboring tau P301L mutation (rTg4510) were examined for a tau-induced central polyamine stress response (tau-PSR). The direct effect of tau-PSR byproducts on tau fibrillization and oligomerization were measured using a thioflavin T assay and a N2a split superfolder GFP-Tau (N2a-ssGT) cell line, respectively. To therapeutically target the tau-PSR, we bilaterally injected caspase 3-cleaved tau truncated at aspartate 421 (AAV9 Tau ΔD421) into the hippocampus and cortex of spermidine/spermine-N¹-acetyltransferase (SSAT), a key regulator of the tau-PSR, knock out (SSAT-/-), and wild type littermates, and the effects on tau neuropathology, polyamine dysregulation, and behavior were measured. Lastly, cellular models were employed to further examine how SSAT repression impacted tau biology.

RESULTS

Tau induced a unique tau-PSR signature in rTg4510 mice, notably in the accumulation of acetylated spermidine. In vitro, higher-order polyamines prevented tau fibrillization but acetylated spermidine failed to mimic this effect and even promoted fibrillization and oligomerization. AAV9 Tau ΔD421 also elicited a unique tau-PSR in vivo, and targeted disruption of SSAT prevented the accumulation of acetylated polyamines and impacted several tau phospho-epitopes. Interestingly, SSAT knockout mice presented with altered behavior in the rotarod task, the elevated plus maze, and marble burying task, thus highlighting the impact of polyamine homeostasis within the brain.

CONCLUSION

These data represent a novel paradigm linking tau pathology and polyamine dysfunction and that targeting specific arms within the polyamine pathway may serve as new targets to mitigate certain components of the tau phenotype.

Everolimus-induced osteonecrosis of the jaw in the absence of bisphosphonates: a case report

Osteonecrosis of the jaw (ONJ) is a rare, but severe, condition that has traditionally been associated with the use of bisphosphonates. We report what is, to our knowledge, the first case of ONJ secondary to the use of everolimus, in the absence of treatment with bisphosphonates in a 65-year-old man who was given it for immunosuppression after a renal transplant. After 18 months of treatment, he was diagnosed with severe ONJ and underwent radical debridement of the palate and complete dental clearance of the maxilla.

Establishing funding rates for colonoscopy and gastroscopy procedures in Ontario

Introduction

This paper describes the funding rates established in Ontario to reflect best practices in hospital-based care delivery for these endoscopic procedures: colonoscopy, colonoscopy biopsy, gastroscopy, gastroscopy biopsy, and colonoscopy combined with gastroscopy.

Methods

The funding rates are based on direct costs and were established using a micro-costing approach after receipt of inputs from 3 working groups and a review of the administrative data and literature, where applicable. The first group advised on nursing activities, time, and staffing ratios along the patient pathway for each of the procedures. The second group provided recommendations about the duration for each procedure, and the third group provided information about supplies and equipment, their use, and costs.

Results

The resulting funding rates are $161.18 for colonoscopy and $151.08 for gastroscopy (without accompanying interventions), $16.06 for colonoscopy biopsy and $8.22 for gastroscopy biopsy (added to the respective procedures), and $207.26 for combined colonoscopy and gastroscopy. Detailed costs for each component embedded in the rates are also provided.

Conclusions

The rates came into effect in April 2018. The process and outcomes described here allowed for a transparent pricing mechanism in which funding follows the patient, clinical expert consensus is the basis for practice, and providers and payers both understand the components.