“Non-healing” claw horn lesions in dairy cows: Clinical, histopathological and molecular biological characterization of four cases

The increasing prevalence of bovine digital dermatitis (BDD) contributes to a higher occurrence of secondary infections of exposed corium with Treponema spp. in bovine claws. “Non-healing” claw horn lesions (NHL) clinically resemble BDD lesions. They are severe, cause chronic lameness, and may persist for several months. They poorly respond to standard treatments of BDD and represent a serious welfare issue. In this study, four cases of NHL were classified clinically either as BDD-associated axial horn fissures (BDD-HFA; n = 3) or BDD-associated sole ulcer (BDD-SU; n = 1). In all four cases, pronounced multifocal keratinolysis of the stratum corneum, ulceration, and severe chronic lymphoplasmacytic perivascular to interstitial dermatitis were observed. All lesional samples tested positive for Treponema spp., Fusobacterium (F.) necrophorum, and Porphyromonas (P.) levii by PCRs. BDD-HFA lesions contained Treponema pedis as revealed by genetic identities of 93, 99, and 100%. Treponemes in the BDD-SU lesion were 94% homologous to Treponema phylotype PT3. Fluorescent in situ hybridization (FISH) revealed extensive epidermal infiltration by treponemes that made up > 90% of the total bacterial population in all four lesions. FISH also tested positive for P. levii and negative for F. necrophorum in all four cases, whilst only one BDD-HFA contained Dichelobacter nodosus. Our data point to BDD-associated treponemes and P. levii constituting potential etiological agents in the development of “non-healing” claw horn lesions in cattle.

ITER collective Thomson scattering-Preparing to diagnose fusion-born alpha particles (invited)

The ITER Collective Thomson scattering (CTS) diagnostic will measure the dynamics of fusion-born alpha particles in the burning ITER plasma by scattering a 1 MW 60 GHz gyrotron beam off fast-ion induced fluctuations in the plasma. The diagnostic will have seven measurement volumes across the ITER cross section and will resolve the alpha particle energies in the range from 300 keV to 3.5 MeV; importantly, the CTS diagnostic is the only diagnostic capable of measuring confined alpha particles for energies below ∼1.7 MeV and will also be sensitive to the other fast-ion populations. The temporal resolution is 100 ms, allowing the capture of dynamics on that timescale, and the typical spatial resolution is 10-50 cm. The development and design of the in-vessel and primary parts of the CTS diagnostic has been completed. This marks the beginning of a new phase of preparation to maximize the scientific benefit of the diagnostic, e.g., by investigating the capability to contribute to the determination of the fuel-ion ratio and the bulk ion temperature as well as integrating data analysis with other fast-ion and bulk-ion diagnostics.

Cardiac arrhythmias 3 months after hospitalization for COVID-19

Background

The long-term frequencies of cardiac arrhythmias in hospitalized coronavirus disease 2019 (COVID-19) patients have not been thoroughly investigated.

Purpose

To describe the prevalence of cardiac arrhythmias, 3–4 months after hospitalization for COVID-19.

Methods and results

Participants with COVID-19 discharged from five large Norwegian hospitals were invited to participate in a prospective cohort study. We examined 201 participants (44% females, mean age 58.5 years) with 24-hour electrocardiogram 3–4 months after discharge. Body mass index (BMI) was 28.3±4.5 kg/m2 (mean ± SD), and obesity (BMI >30) was found in 70 participants (34%). Clinically significant arrhythmias were defined as; ventricular tachycardia (non-sustained or sustained), premature ventricular contractions (PVC) exceeding 200/24 h, or coupled PVC, atrial fibrillation/flutter, second-degree atrioventricular block (AV-block) type 2, complete AV-block, sinoatrial (SA) block exceeding 3 s, premature AV-nodal beats in bigeminy, supraventricular tachycardia (SVT) exceeding 30 s, and sinus bradycardia with less than 30 beats/min. High-sensitive cardiac troponin T (hs-cTnT) was measured at the 3-month follow-up.

Results

Cardiac arrhythmias were found in 27% (n=54) of the participants. Ventricular premature contractions and non-sustained ventricular tachycardia were the most common arrhythmias, found in 22% (n=44) of the participants. Premature ventricular contractions were the most frequent cardiac arrhythmia. More than 200 PVCs per day were observed in 37 participants (18%) with a mean of 1300 PVC/day, and in 35 (95%) of these participants, the PVCs were polymorphic.

Among 10 patients experiencing NSVT, 5 participants had previous CVD, including coronary heart disease (n=1), 1 atrial fibrillation, 2 venous thromboembolism, 4 heart failure. Atrial fibrillation was found in seven patients (3%), none of them of new-onset.

SA block >3 seconds was only observed in one patient, and no incidence of high degree AV block was discovered. Pre-existing cardiovascular disease or hypertension (CVDH) were reported in 40% (n=81) of the participants. The CVDH group had an increased amount of arrhythmia compared to the group free of CVDH (p=0.04). High PVCs showed a fair correlation with hs-cTnT levels at 3 months (ρ=0.21 p=0.048).

Conclusions

Three months following hospital discharge with COVID-19, cardiac arrhythmia was found in every fourth participant and was associated with a higher concentration of hs-cTnT at 3 months. The clinical implications of persistent ventricular arrhythmia following COVID-19 is not clear, but ventricular ectopy has been linked to increased risk of cardiac disease, including cardiomyopathy and sudden cardiac death.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The National Association for Heart, Lung diseases and the Norwegian Health Association and Akershus University Hospital.

Fast production of microwave component prototypes by additive manufacturing and copper coating

We present a novel method for efficient production of prototypes of microwave components by fused depositing modeling, also known as 3D plastic printing, and vapor deposition coating of a 1 μm copper layer. We demonstrate that the properties of the components follow the predicted performance for low power microwave propagation. The production method offers new opportunities for cheap and efficient production of mock-ups and prototypes of advanced-geometry components for tests with low-power microwaves.

3304High sensitive cardiac troponin i at admission and 30 minutes later to rule-in or rule-out acute myocardial infarction - Preliminary results from the RACING-MI trial

Introduction

Current ESC guidelines have introduced a 0h/1h algorithm for accelerated rule-in or rule-out of acute myocardial infarction (MI) when using assay specific high-sensitive cardiac troponin I (hs-cTnI). Several studies have investigated the diagnostic performance and safety of this approach using different hs-cTnI assays. However, little is known of the diagnostic performance of a 0h/30min algorithm.

Purpose

To evaluate the diagnostic accuracy of early rule-in or rule-out of MI after 30 minutes by applying assay specific hs-cTnI cut-off values from a recently validated 0h/1h algorithm.

Methods

We prospectively enrolled chest pain patients suggestive of MI admitted to the Emergency Department. Patients underwent serial hs-cTnI measurements at admission (0 hour) and after 3 hours according to clinical practice. In addition, hs-cTnI measurements were performed after 30 minutes. The assay specific cut-off values from the 0h/1h algorithm were applied to the 30 minute cohort (figure 1). Final diagnosis was adjudicated independently by two physicians.

Results

In total, 943 patients were included. MI was the final diagnosis in 67 (7.1%) patients. Overall, absolute hs-cTnI values after 30 minutes were significantly higher in the MI group than in the non-MI group (19.2 (Q1:Q3) 2.7–75.3) ng/L versus 0.1 (0.2–0.7) ng/L, p<0.001). When applying the assay-specific hs-cTnI cut-off valuesfor the 0h/1h algorithmto the 30 minute patient cohort, 52.4% of patients were classified as rule-out with a negative predictive value of 100% (95% CI: 99.2–100). In total, 8.5% were classified as rule-in with a positive predictive value of 83.8% (95% CI: 74.2–90.3). Sensitivity was 100% (95% CI: 94.6–100) and specificity was 97.4% (95% CI: 95.7–98.6). Overall, 39.1% were assigned to the observational zone with a 3.5% prevalence of MI.

Conclusions

The use of assay specific hs-cTnI measurement at admission (0h) and 30 min later can be used to safely rule-out MI. This indicates that it might be safe to develop a 0h/30min algorithm and hereby reduce time to diagnosis even further. NCT03634384.

Acknowledgement/Funding

Randers Regional Hospital, A.P Møller Foundation, Boserup Foundation, Korning Foundation, Højmosegård Grant, Siemens Healthcare (TNIH assays), etc.

P2673Challenging time limits: Using a single high-sensitive troponin I to rule-out acute myocardial infarction in early presenters

Introduction

According to ESC guidelines, an acute myocardial infarction (MI) can be excluded without serial troponin measurements in patients presenting with a single high-sensitive troponin below the 99th percentile and chest pain starting >6 hours prior to admission. However, it is unclear if single-testing of high-sensitive troponin can rule-out MI in early presenters.

Purpose

To investigate the diagnostic performance of a single value of high-sensitive cardiac troponin I (hs-cTnI) at presentation for ruling-out MI in patients presenting with chest pain to the Emergency Department irrespective of chest pain onset.

Methods

We conducted a substudy of preliminary data from the RACING-MI trial. We included patients presenting with chest pain suggestive of MI to the Emergency Department of a Regional Hospital. We used the Siemens hs-cTnI (Siemens Healthcare, TNIH, Limit of detection: 2.21 ng/L) and a diagnostic cut-off value <3 ng/L to rule-out MI at presentation. Two physicians independently adjudicated the final diagnosis based on all clinical information. Patients were stratified based on time from chest pain onset to hospital admission as very early (0–3 hours), early (3–6 hours) and late presenters (>6 hours).

Results

We included 989 patients with available hs-cTnI results at admission. MI was confirmed in 82 (8.3%) patients. Using hs-cTnI <3 ng/L as diagnostic cut-off value at presentation, 302 (30.5%) patients without MI were classified as rule-out. Overall, the negative predictive value (NPV) for MI was 100% (95% CI 98.7–100).

Based on chest pain onset, 33.8% of patients were classified as very early, 12.8% as early, and 42.7% as late presenters, with 10.7% patients with unreported/unknown onset. NPV was 100% (95% CI 96.5–100) for very early, 100% (95% CI 88.3–100) for early and 100% (95% CI 97.3–100) for late presenters.

Conclusions

Using a single hs-cTnI value <3ng/L as diagnostic cut-off to rule-out MI seems to be safe and to allow rapid rule-out of MI in patients presenting with chest pain to the emergency department, even in very early presenters.

ClinicalTrials.gov Identifier: NCT03634384.

Acknowledgement/Funding

Randers Regional Hospital, A.P Møller Foundation, Boserup Foundation, Korning Foundation, Højmosegård Grant, Siemens Healthcare (TNIH assays), etc.

Forward modeling of collective Thomson scattering for Wendelstein 7-X plasmas: Electrostatic approximation

In this paper, we present a method for numerical computation of collective Thomson scattering (CTS). We developed a forward model, eCTS, in the electrostatic approximation and benchmarked it against a full electromagnetic model. Differences between the electrostatic and the electromagnetic models are discussed. The sensitivity of the results to the ion temperature and the plasma composition is demonstrated. We integrated the model into the Bayesian data analysis framework Minerva and used it for the analysis of noisy synthetic data sets produced by a full electromagnetic model. It is shown that eCTS can be used for the inference of the bulk ion temperature. The model has been used to infer the bulk ion temperature from the first CTS measurements on Wendelstein 7-X.

189 Isolation and purification of rhinoceros and horse spermatogonial stem cells

The northern white rhinoceros (NWR; Ceratotherium simum cottoni) is critically endangered. Testicular tissue (TT) of an NWR that died at 46 years was cryopreserved and stored. Spermatogonial stem cells (SSC) have been isolated from TT and, following transplantation or in vitro culture, differentiated into mature spermatozoa. These SSC have been phenotypically characterised by the expression of markers specific for SSC, and in vitro culture methods optimized to isolate, purify, and enrich populations of SSC from mixed germ cells. The reproductive age may affect the percent of SSC in TT, affecting recovery from older animals. We previously identified in TT of NWR the surface markers GFRa1 and GPR125, both of which were expressed at various stages of spermatogenesis. However, characterisation, isolation, and purification of rhinoceros SSC have not been studied. Because of the limited availability of rhinoceros TT, we used the horse as a model for rhinoceros (both species are in the same order: Perissodactyla). In this study, we (1) identified and compared the expression of markers specific for SSC (GFRa1, GPR125, PLZF) and pluripotent markers (SSEA-1, SSEA-4, OCT-4) in rhinoceros and horse mixed germ cells; (2) evaluated whether rhinoceros and horse SSC could be purified and enriched by sequential culture with collagen (2 days) and laminin (3 weeks); and (3) determined whether age may affect the percentages of SSC by comparing the expression of SSC and pluripotent markers in horse mixed germ cells at different reproductive stages: pubertal (PU=1-1.5 years) v. post-pubertal (PP=2-3 years) v. adult (AD=&gt;5 years). Mixed germ cells were isolated from testes of one male of each of 3 rhinoceros species: NWR, southern white rhinoceros (SWR; Ceratotherium simum simum, 49 years), and greater one-horned rhinoceros (GOHR; Rhinoceros unicornis, 5 years), and horses at different reproductive stages (PU=2, PP=2, AD=7). The SWR and GOHR testes were refrigerated overnight, whereas NWR mixed germ cells were isolated from frozen-thawed TT. Flow cytometry analysis showed expression of SSC and pluripotent markers but not for transcription factor PLZF. The marker expression was similarly distributed between the 3 species of rhinoceros, with a larger portion of cells positive for SSEA-4 (mean%±s.e.m.: 6.3±1.1%) and smaller proportion for GDNFa1 (0.4±0.2%), GRP125 (0.1±0.1%), OCT-4 (0.4±0.2%), and SSEA-1 (0.4±0.2%; P&lt;0.05). Similarly, horse expressed the markers GDNFa1 (0.9±0.3%), GRP125 (0.9±0.4%), OCT-4 (1.7±0.5%), and SSEA-1 (0.12±0.1%), but the abundance of SSEA-4 (1.8±0.8%) was less than that of rhinoceros (P&lt;0.05). In rhinoceros, sequential culture enhanced the numbers of cells expressing all markers compared with that before culture, whereas in horses, the increase was observed only for cells expressing GDNFa1, GPR125, and SSEA-1. Reproductive stage did not affect the percentages of horse cells expressing germ cell and pluripotent markers. Overall, these results showed that rhinoceros SSC can be isolated from TT and expressed the same SSC markers as horses, and that differential culture enriched a population of SSC.

The effect of metformin versus placebo in combination with insulin analogues on bone mineral density and trabecular bone score in patients with type 2 diabetes mellitus: a randomized placebo-controlled trial

Some antihyperglycemic medications have been found to affect bone metabolism. We assessed the long-term effects of metformin compared with placebo on bone mineral density (BMD) and trabecular bone score (TBS) in patients with type 2 diabetes. Metformin had no significant effect on BMD in the spine and hip or TBS compared with a placebo.

INTRODUCTION

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of fractures despite a high bone mass. Some antihyperglycemic medications have been found to affect bone metabolism. We assessed the long-term effects of metformin compared with placebo on bone mineral density (BMD) and trabecular bone score (TBS).

METHODS

This was a sub-study of a multicenter, randomized, 18-month placebo-controlled, double-blinded trial with metformin vs. placebo in combination with different insulin regimens (the Copenhagen Insulin and Metformin Therapy trial) in patients with T2DM. BMD in the spine and hip and TBS in the spine were assessed by dual-energy X-ray absorptiometry at baseline and after 18 months follow-up.

RESULTS

Four hundred seven patients were included in this sub-study. There were no between-group differences in BMD or TBS. From baseline to 18 months, TBS decreased significantly in both groups (metformin group, - 0.041 [- 0.055, - 0.027]; placebo group - 0.046 [- 0.058, - 0.034]; both p < 0.001). BMD in the spine and total hip did not change significantly from baseline to 18 months. After adjustments for gender, age, vitamin D, smoking, BMI, duration of T2DM, HbA1c, and insulin dose, the TBS between-group differences increased but remained non-significant. HbA_1c was negatively associated with TBS (p = 0.009) as was longer duration of diabetes, with the femoral neck BMD (p = 0.003). Body mass index had a positive effect on the hip and femoral neck BMD (p < 0.001, p = 0.045, respectively).

CONCLUSIONS

Eighteen months of treatment with metformin had no significant effect on BMD in the spine and hip or TBS in patients with T2DM compared with a placebo. TBS decreased significantly in both groups.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT00657943).

Tristetraprolin Is Required for Alveolar Bone Homeostasis

Tristetraprolin (TTP) is an RNA-binding protein that targets numerous immunomodulatory mRNA transcripts for degradation. Many TTP targets are key players in the pathogenesis of periodontal bone loss, including tumor necrosis factor-α. To better understand the extent that host immune factors play during periodontal bone loss, we assessed alveolar bone levels, inflammation and osteoclast activity in periodontal tissues, and immune response in draining cervical lymph nodes in TTP-deficient and wild-type (WT) mice in an aging study. WT and TTP-deficient (knockout [KO]) mice were used for all studies under specific pathogen-free conditions. Data were collected on mice aged 3, 6, and 9 mo. Microcomputed tomography (µCT) was performed on maxillae where 3-dimensional images were generated and bone loss was assessed. Decalcified sections of specimens were scored for inflammation and stained with tartrate-resistant acid phosphate (TRAP) to visualize osteoclasts. Immunophenotyping was performed on single-cell suspensions isolated from primary and peripheral lymphoid tissues using flow cytometry. Results presented indicate that TTP KO mice had significantly more alveolar bone loss over time compared with WT controls. Bone loss was associated with significant increases in inflammatory cell infiltration and an increased percentage of alveolar bone surfaces apposed with TRAP+ cells. Furthermore, it was found that the draining cervical lymph nodes were significantly enlarged in TTP-deficient animals and contained a distinct pathological immune profile compared with WT controls. Finally, the oral microbiome in the TTP KO mice was significantly different with age from WT cohoused mice. The severe bone loss, inflammation, and increased osteoclast activity observed in these mice support the concept that TTP plays a critical role in the maintenance of alveolar bone homeostasis in the presence of oral commensal flora. This study suggests that TTP is required to inhibit excessive inflammatory host responses that contribute to periodontal bone loss, even in the absence of specific periodontal pathogens.

Comparing effects of insulin analogues and human insulin on nocturnal glycaemia in hypoglycaemia-prone people with Type 1 diabetes

AIMS

To assess the difference between analogue and human insulin with regard to nocturnal glucose profiles and risk of hypoglycaemia in people with recurrent severe hypoglycaemia.

METHODS

A total of 72 people [46 men, mean ± sd age 54 ± 12 years, mean ± sd HbA_1c 65 ± 12 mmol/mol (8.1 ± 1.1%), mean ± sd duration of diabetes 30 ± 14 years], who participated in a 2-year randomized, crossover trial of basal-bolus therapy with insulin detemir/insulin aspart or human NPH insulin/human regular insulin (the HypoAna trial) were studied for 2 nights during each treatment. Venous blood was drawn hourly during sleep. Primary endpoints were nocturnal glucose profiles and occurrence of hypoglycaemia (blood glucose ≤ 3.9 mmol/l).

RESULTS

During insulin analogue treatment, the mean nocturnal plasma glucose level was significantly higher than during treatment with human insulin (10.6 vs 8.1 mmol/l). The fasting plasma glucose level was similar between the treatments. Nocturnal hypoglycaemia was registered during 41/101 nights (41%) in the human insulin arm and 19/117 nights (16%) in the insulin analogue arm, corresponding to a hazard ratio of 0.26 (95% CI 0.14 to 0.45; P < 0.0001) with insulin analogue.

CONCLUSIONS

Treatment with insulin analogue reduces the occurrence of nocturnal hypoglycaemia assessed by nocturnal glucose profiles in people with Type 1 diabetes prone to severe hypoglycaemia. Nocturnal glucose profiles provide a more comprehensive assessment of clinical benefit of insulin regimens as compared to conventional recording of hypoglycaemia.

Lateral ridge augmentation with Bio-Oss alone or Bio-Oss mixed with particulate autogenous bone graft: a systematic review

The objective of this systematic review was to test the hypothesis of no difference in implant treatment outcomes when using Bio-Oss alone or Bio-Oss mixed with particulate autogenous bone grafts for lateral ridge augmentation. A search of the MEDLINE, Cochrane Library, and Embase databases in combination with a hand-search of relevant journals was conducted. Human studies published in English from 1 January 1990 to 1 May 2016 were included. The search provided 337 titles and six studies fulfilled the inclusion criteria. Considerable variation prevented a meta-analysis from being performed. The two treatment modalities have never been compared within the same study. Non-comparative studies demonstrated a 3-year implant survival of 96% with 50% Bio-Oss mixed with 50% autogenous bone graft. Moreover, Bio-Oss alone or Bio-Oss mixed with autogenous bone graft seems to increase the amount of newly formed bone as well as the width of the alveolar process. Within the limitations of this systematic review, lateral ridge augmentation with Bio-Oss alone or in combination with autogenous bone graft seems to induce newly formed bone and increase the width of the alveolar process, with high short-term implant survival. However, long-term studies comparing the two treatment modalities are needed before final conclusions can be drawn.

Hand bone loss in early rheumatoid arthritis during a methotrexate-based treat-to-target strategy with or without adalimumab-a substudy of the optimized treatment algorithm in early RA (OPERA) trial

This study aims to investigate 1-year hand bone loss (HBL_1-year) in early rheumatoid arthritis (RA) patients treated with a methotrexate (MTX) and intra-articular triamcinolone treat-to-target strategy +/- adalimumab and to determine if HBL_6months is associated with radiographic progression after 2 years. In a clinical trial (OPERA) of 180 treatment-naive early RA patients, bone mineral density (BMD) was estimated from hand radiographs with digital X-ray radiogrammetry (DXR) at baseline, after 6 (n = 90) and 12 months (n = 70) of follow-up. Baseline and 2-year radiographs were scored according to the Sharp/van der Heijde method. Baseline characteristics and HBL_6months (0-6 months changes in DXR-BMD) were investigated as predictors of structural damage by univariate linear (∆ total Sharp/van der Heijde score (TSS) as dependent variable) and logistic (+/-radiographic progression (∆TSS >0) as dependent variable) regression analyses. Variables with p < 0.10 were included in multivariable models. In 70 patients with available HBL_1-year data, HBL_1-year was median (interquartile range (IQR)) -1.9 (-3.3; -0.26 mg/cm²) in the MTX + placebo group and -1.8 (-3.6; 0.06) mg/cm² in the MTX + adalimumab group, p = 0.98, Wilcoxon signed-rank. Increased HBL (compared to general population reference values) was found in 26/37 and 23/33 patients in the MTX + placebo and MTX + adalimumab groups, chi-squared = 0.99. In 90 patients with HBL_6months data and 2-year radiographic data, HBL_6months was independently associated with ∆TSS after 2 years (β = -0.086 (95% confidence interval = -0.15; -0.025) TSS unit/mg/cm² increase, p = 0.006) but not with presence of radiographic progression (∆TSS >0) (OR 0.96 (0.92-1.0), p = 0.10). In early RA patients treated with a methotrexate-based treat-to-target strategy, the majority of patients had increased HBL_1-year, irrespective of adalimumab; HBL_6months was independently associated with ∆TSS after 2 years.

Discrepancies between cortical and behavioural long-term readouts of hyperalgesia in awake freely moving rats

Background

It is still unclear to what extent the most common animal models of pain and analgesia, based on indirect measures such as nocifensive behaviours, provide valid measures of pain perception.

Methods

To address this issue, we developed a novel animal model comprising a more direct readout via chronically (>1 month) implanted multichannel electrodes (MCE) in rat primary somatosensory cortex (S1; known to be involved in pain perception in humans) and compared this readout to commonly used behavioural pain‐related measures during development of hyperalgesia. A translational method to induce hyperalgesia, UVB irradiation of the skin, was used. Localized CO₂ laser stimulation was made of twenty skin sites (20 stimulations/site/observation day) on the plantar hind paw, before and during the time period when enhanced pain perception is reported in humans after UVB irradiation.

Results

We demonstrate a 2–10 fold significant enhancement of cortical activity evoked from both irradiated and adjacent skin and a time course that corresponds to previously reported enhancement of pain magnitude during development of primary and secondary hyperalgesia in humans. In contrast, withdrawal reflexes were only significantly potentiated from the irradiated skin area and this potentiation was significantly delayed as compared to activity in S1.

Conclusions

The present findings provide direct evidence that chronic recordings in S1 in awake animals can offer a powerful, and much sought for, translational model of the perception of pain magnitude during hyperalgesia.

What does this study add?

In a novel animal model, chronic recordings of nociceptive activity in primary somatosensory cortex (S1) in awake freely moving rats are compared to behavioural readouts during UVB‐induced hyperalgesia. Evoked activity in rat S1 replicates altered pain perception in humans during development of hyperalgesia, but withdrawal reflexes do not.

Mechanisms by Which Dehydration May Lead to Chronic Kidney Disease

Dehydration, a condition that characterizes excessive loss of body water, is well known to be associated with acute renal dysfunction; however, it has largely been considered reversible and to be associated with no long-term effects on the kidney. Recently, an epidemic of chronic kidney disease has emerged in Central America in which the major risk factor seems to be recurrent heat-associated dehydration. This has led to studies investigating whether recurrent dehydration may lead to permanent kidney damage. Three major potential mechanisms have been identified, including the effects of vasopressin on the kidney, the activation of the aldose reductase-fructokinase pathway, and the effects of chronic hyperuricemia. The discovery of these pathways has also led to the recognition that mild dehydration may be a risk factor in progression of all types of chronic kidney diseases. Furthermore, there is some evidence that increasing hydration, particularly with water, may actually prevent CKD. Thus, a whole new area of investigation is developing that focuses on the role of water and osmolarity and their influence on kidney function and health.

Regulation of the cystic fibrosis transmembrane conductance regulator anion channel by tyrosine phosphorylation

The cystic fibrosis transmembrane conductance regulator (CFTR) channel is activated by PKA phosphorylation of a regulatory domain that interacts dynamically with multiple CFTR domains and with other proteins. The large number of consensus sequences for phosphorylation by PKA has naturally focused most attention on regulation by this kinase. We report here that human CFTR is also phosphorylated by the tyrosine kinases p60c-Src (proto-oncogene tyrosine-protein kinase) and the proline-rich tyrosine kinase 2 (Pyk2), and they can also cause robust activation of quiescent CFTR channels. In excised patch-clamp experiments, CFTR activity during exposure to Src or Pyk2 reached ∼80% of that stimulated by PKA. Exposure to PKA after Src or Pyk2 caused a further increase to the level induced by PKA alone, implying a common limiting step. Channels became spontaneously active when v-Src or the catalytic domain of Pyk2 was coexpressed with CFTR and were further stimulated by the tyrosine phosphatase inhibitor dephostatin. Exogenous Src also activated 15SA-CFTR, a variant that lacks 15 potential PKA sites and has little response to PKA. PKA-independent activation by tyrosine phosphorylation has implications for the mechanism of regulation by the R domain and for the physiologic functions of CFTR.

Targeted proteomic quantitation of the absolute expression and turnover of cystic fibrosis transmembrane conductance regulator in the apical plasma membrane

Deficient chloride transport through cystic fibrosis (CF) transmembrane conductance regulator (CFTR) causes lethal complications in CF patients. CF is the most common autosomal recessive genetic disease, which is caused by mutations in the CFTR gene; thus, CFTR mutants can serve as primary targets for drugs to modulate and rescue the ion channel’s function. The first step of drug modulation is to increase the expression of CFTR in the apical plasma membrane (PM); thus, accurate measurement of CFTR in the PM is desired. This work reports a tandem enrichment strategy to prepare PM CFTR and uses a stable isotope labeled CFTR sample as the quantitation reference to measure the absolute amount of apical PM expression of CFTR in CFBE 41o- cells. It was found that CFBE 41o- cells expressing wild-type CFTR (wtCFTR), when cultured on plates, had 2.9 ng of the protein in the apical PM per million cells; this represented 10% of the total CFTR found in the cells. When these cells were polarized on filters, the apical PM expression of CFTR increased to 14%. Turnover of CFTR in the apical PM of baby hamster kidney cells overexpressing wtCFTR (BHK-wtCFTR) was also quantified by targeted proteomics based on multiple reaction monitoring mass spectrometry; wtCFTR had a half-life of 29.0 ± 2.5 h in the apical PM. This represents the first direct measurement of CFTR turnover using stable isotopes. The absolute quantitation and turnover measurements of CFTR in the apical PM can significantly facilitate understanding the disease mechanism of CF and thus the development of new disease-modifying drugs. Absolute CFTR quantitation allows for direct result comparisons among analyses, analysts, and laboratories and will greatly amplify the overall outcome of CF research and therapy.

Mitochondrial 12S ribosomal RNA A1555G mutation associated with cardiomyopathy and hearing loss following high-dose chemotherapy and repeated aminoglycoside exposure

A 19-month-old girl with the A1555G mitochondrial mutation in the 12S ribosomal RNA gene and acute myelogenous leukemia developed dilated cardiomyopathy and bilateral sensorineural hearing loss before undergoing allogeneic stem cell transplantation. She had received gentamicin during episodes of febrile neutropenia. Testing for the A1555G mutation is recommended in patients frequently treated with aminoglycosides.

Ongoing multi-strain food-borne hepatitis A outbreak with frozen berries as suspected vehicle: four Nordic countries affected, October 2012 to April 2013

Binary file ES_Abstracts_Final_ECDC.txt matches

A verocytotoxin-producing E. coli outbreak with a surprisingly high risk of haemolytic uraemic syndrome, Denmark, September-October 2012

Denmark faced an outbreak of verocytotoxin-producing E. coli (VTEC) O157:H7 infections in autumn 2012. Thirteen cases were diagnosed of which eight had haemolytic uraemic syndrome (HUS). Epidemiological investigations suggested ground beef as the vehicle of the outbreak. The outbreak strain had a rare toxin gene subtype profile: eae, vtx1a and vtx2a, and a high proportion of HUS (62%) among cases, a finding previously linked with the outbreak subtype profile. Toxin subtyping can be useful to identify high risk VTEC strains.

A verocytotoxin-producing E. coli outbreak with a surprisingly high risk of haemolytic uraemic syndrome, Denmark, September-October 2012

Denmark faced an outbreak of verocytotoxin-producing E. coli (VTEC) O157:H7 infections in autumn 2012. Thirteen cases were diagnosed of which eight had haemolytic uraemic syndrome (HUS). Epidemiological investigations suggested ground beef as the vehicle of the outbreak. The outbreak strain had a rare toxin gene subtype profile: eae, vtx1a and vtx2a, and a high proportion of HUS (62%) among cases, a finding previously linked with the outbreak subtype profile. Toxin subtyping can be useful to identify high risk VTEC strains.

280 OSTEOGENIC ACTIVITY OF IN HOUSE-PRODUCED PORCINE BMP2 ON ADIPOSE-DERIVED STEM CELLS

In our laboratory, we extensively study the possibility of using adipose-derived stem cells (ASC) for maxillofacial bone regeneration. This includes also the tissue repair of large critical-size osteotomies requiring the use of tridimensional scaffolds. Bone regeneration in scaffolds can be greatly enhanced by the use of specific growth factors such as BMP2. In the present study, we compared the activity of commercially available human BMP2 (hBMP2) with in house-produced porcine BMP2 (pBMP2). The latter was synthesised using the BMP2 coding sequence from mRNA obtained from porcine ASC cell cultures. The coding sequence of the mature protein was cloned into a pET-21 plasmid and produced in E. coli as inclusion bodies. The activity of pBMP2 and hBMP2 was tested on ASC isolated from male pigs at passage 4 and at approximately 80% confluence in 48-well plates. Cells were treated in triplicate with hBMP2 or pBMP2 at 0.5, 5, 50, 500, or 1000 ng mL–1, adipogenic medium (AM), osteogenic medium (OM), or normal DMEM medium supplemented with acetic acid (used to resuspend BMP2 as the control) for 5 or 17 days. Cells were harvested for Alizarin Red S (AR) quantification and expression of osteogenic genes. For the AR analysis, cells were fixed with formalin and treated with AR. The AR was then extracted by acetic acid and neutralized with ammonium hydroxide before spectrophotometer reading at an absorbance of 420 nm. Data were analysed using GLM of SAS (SAS Institute Inc., Cary, NC, USA) with treatment, time, concentration, and all interactions as main effects. Using an inverted robotic stage microscope, images of the entire well for each replicate were taken every 2 to 3 days. Images revealed formation of osteogenic nodules in OM and characteristic large cells filled with lipid droplets in AM. No evident nodule formation was observed in the other treated cells at any time point. The AR was higher than control in both hBMP2 and pBMP2 at 0.5, 50, and 1000 ng mL–1 but not at 5 and 500 ng mL–1. There was no overall difference between hBMP2 and pBMP2 but the former had the highest AR value at 5 days in cells treated with 0.5 ng mL–1 and pBMP2 at 17 days with 1000 ng mL–1. Interestingly, both had higher values compared to OM, particularly at 5 days. We also observed an increase of AR due to time in cells treated with acetic acid (control). Overall, the data appear to indicate an increase in calcium accumulation in cells treated with both hBMP2 and pBMP2, with an early increase in the former and a late and larger increase in the latter. This might indicate a larger but slower activity of pBMP2 compared with hBMP2. The lack of formation of osteogenic nodules by both BMP2 might indicate an insufficiency of BMP2 to induce osteogenesis in porcine ASC. This last observation, together with the lack of increased AR accumulation compared with control at the 5 and 50 ng mL–1 doses, suggests the need for a more accurate analysis of BMP2 activity by measuring expression of BMP2-related genes. Finally, the data provide preliminary support for the equivalency of activity of pBMP2 and hBMP2 for in vivo bone regeneration.

Correctors of ΔF508 CFTR restore global conformational maturation without thermally stabilizing the mutant protein

Most cystic fibrosis is caused by the deletion of a single amino acid (F508) from CFTR and the resulting misfolding and destabilization of the protein. Compounds identified by high-throughput screening to improve ΔF508 CFTR maturation have already entered clinical trials, and it is important to understand their mechanisms of action to further improve their efficacy. Here, we showed that several of these compounds, including the investigational drug VX-809, caused a much greater increase (5- to 10-fold) in maturation at 27 than at 37°C (<2-fold), and the mature product remained short-lived (T(1/2)∼4.5 h) and thermally unstable, even though its overall conformational state was similar to wild type, as judged by resistance to proteolysis and interdomain cross-linking. Consistent with its inability to restore thermodynamic stability, VX-809 stimulated maturation 2-5-fold beyond that caused by several different stabilizing modifications of NBD1 and the NBD1/CL4 interface. The compound also promoted maturation of several disease-associated processing mutants on the CL4 side of this interface. Although these effects may reflect an interaction of VX-809 with this interface, an interpretation supported by computational docking, it also rescued maturation of mutants in other cytoplasmic loops, either by allosteric effects or via additional sites of action. In addition to revealing the capabilities and some of the limitations of this important investigational drug, these findings clearly demonstrate that ΔF508 CFTR can be completely assembled and evade cellular quality control systems, while remaining thermodynamically unstable. He, L., Kota, P., Aleksandrov, A. A., Cui, L., Jensen, T., Dokholyan, N. V., Riordan, J. R. Correctors of ΔF508 CFTR restore global conformational maturation without thermally stabilizing the mutant protein.

[Plastic bronchitis in a ten year-old boy with Fontan circulation]

Plastic bronchitis is a rare complication in children with inflammatory lung disease and postoperatively after Fontan operation for congenital heart disease. Plastic bronchitis is characterised by expectoration of large bronchial casts, which can cause fatal airway obstruction. We describe a case of a ten year-old boy with transposition vasorum and hypoplastic right ventricle who underwent a Fontan operation at the age of three. Seven years postoperatively he developed plastic bronchitis which was treated with mucolytics, inhaled corticosteroids, β2-agonist, hypertonic NaCl, and chest physiotherapy, resulting in partial recovery.

Allosteric modulation balances thermodynamic stability and restores function of ΔF508 CFTR

Most cystic fibrosis is caused by a deletion of a single residue (F508) in CFTR (cystic fibrosis transmembrane conductance regulator) that disrupts the folding and biosynthetic maturation of the ion channel protein. Progress towards understanding the underlying mechanisms and overcoming the defect remains incomplete. Here, we show that the thermal instability of human ΔF508 CFTR channel activity evident in both cell-attached membrane patches and planar phospholipid bilayers is not observed in corresponding mutant CFTRs of several non-mammalian species. These more stable orthologs are distinguished from their mammalian counterparts by the substitution of proline residues at several key dynamic locations in first N-terminal nucleotide-binding domain (NBD1), including the structurally diverse region, the γ-phosphate switch loop, and the regulatory insertion. Molecular dynamics analyses revealed that addition of the prolines could reduce flexibility at these locations and increase the temperatures of unfolding transitions of ΔF508 NBD1 to that of the wild type. Introduction of these prolines experimentally into full-length human ΔF508 CFTR together with the already recognized I539T suppressor mutation, also in the structurally diverse region, restored channel function and thermodynamic stability as well as its trafficking to and lifetime at the cell surface. Thus, while cellular manipulations that circumvent its culling by quality control systems leave ΔF508 CFTR dysfunctional at physiological temperature, restoration of the delicate balance between the dynamic protein's inherent stability and channel activity returns a near-normal state.