Prion protein conversion at two distinct cellular sites precedes fibrillisation.

The self-templating nature of prions plays a central role in prion pathogenesis and is associated with infectivity and transmissibility. Since propagation of proteopathic seeds has now been acknowledged a principal pathogenic process in many types of dementia, more insight into the molecular mechanism of prion replication is vital to delineate specific and common disease pathways. By employing highly discriminatory anti-PrP antibodies and conversion-tolerant PrP chimera, we here report that de novo PrP conversion and formation of fibril-like PrP aggregates are distinct in mechanistic and kinetic terms. De novo PrP conversion occurs within minutes after infection at two subcellular locations, while fibril-like PrP aggregates are formed exclusively at the plasma membrane, hours after infection. Phenotypically distinct pools of abnormal PrP at perinuclear sites and the plasma membrane show differences in N-terminal processing, aggregation state and fibril formation and are linked by exocytic transport via synaptic and large-dense core vesicles.

Thermal dynamics of few-layer-graphene seals.

Being of atomic thickness, graphene is the thinnest imaginable membrane. While graphene's basal plane is highly impermeable at the molecular level, the impermeability is, in practice, compromised by leakage pathways located at the graphene-substrate interface. Here, we provide a kinetic analysis of such interface-mediated leakage by probing gas trapped in graphene-sealed SiO2 cavities versus time and temperature using electron energy loss spectroscopy. The results show that gas leakage exhibits an Arrhenius-type temperature dependency with apparent activation energies between 0.2 and 0.7 eV. Surprisingly, the interface leak rate can be improved by several orders of magnitude by thermal processing, which alters the kinetic parameters of the temperature dependency. The present study thus provides fundamental insight into the leakage mechanism while simultaneously demonstrating thermal processing as a generic approach for tightening graphene-based-seals with applications within chemistry and biology.

Is cross-sectional imaging necessary for fractures of the distal lower leg in children and adolescents: results of a nationwide survey.

PURPOSE: In childhood and adolescence, cross-sectional imaging, most commonly computed tomography (CT), is often performed for advanced diagnosis of joint injuries of the distal lower leg and upper ankle. Due to radiation exposure, the need for CT remains controversial, as these injuries follow stereotypies and usually have a similar course. Alternatively, the performance of magnetic resonance imaging (MRI) is also discussed. Since radiation sensitivity at this young age is much higher than in adults, an effort must be to minimize radiation exposure according to as low as reasonably achievable (ALARA) principles. The aim of this survey is to evaluate the current procedure in Germany in the diagnosis of pediatric injuries of the distal lower leg and upper ankle. METHODS: For data collection, a survey entitled "CT in fractures of the ankle joint in childhood and adolescence: subject of the survey are injuries between 8 and 15 years of age" of the Section of Pediatric Traumatology in the German Association of Trauma Surgery was sent to all members via the distribution list of the German Society of Orthopedics and Traumatology and the distribution list of the German Society of Pediatric Surgery in a period from September 20, 2022-December 21, 2022. The survey included a total of 21 questions. Target groups were trauma and pediatric surgeons and orthopedic surgeons working in the hospital and in practice. RESULTS: A total of 525 participants took part in the survey: ultrasound diagnostics are used by almost 25% and the Ottawa Ankle Rules by over 50% always or in most cases. A conventional x-ray is always or most often used by over 90%. CT imaging is rarely used by 88.57%, mainly for surgical planning or analysis of fracture progression. 69.9% report that their radiology department uses a pediatric protocol for CT exams; 25.71% do not know if this is the case. MRI imaging is also used infrequently by 89.33%, mostly to identify associated injuries. Overall, CT imaging is chosen by 55.62% and MRI imaging by 35.24% as the sectional imaging modality for suspected fractures; 95.05% consider sectional imaging useful for a triplane fracture, 59.24% for a two-plane fracture, 41.71% for a Salter-Harris type III/IV injury, and 8% for a Salter-Harris type I/II injury. CONCLUSION: The survey showed that the conventional X-ray is still the gold standard. Interestingly, more than half of the respondents regularly use the Ottawa Ankle Rules, and diagnostics using ultrasound are also used by almost a quarter. Awareness of radiation protection in children exists, although a quarter of all participants do not know the extent to which their radiology department has a specific pediatric protocol for CT imaging. Cross-sectional imaging is performed on a regular basis. Regarding the actual extent of imaging, there is a clear divergence between theory and practice.

Percutaneous ultrasound-guided needle tenotomy for treatment of chronic tendinopathy and fasciopathy: a meta-analysis.

OBJECTIVES: To systematically assess the efficacy of percutaneous ultrasound-guided needle tenotomy (PUNT) in the treatment of chronic tendinopathy and fasciopathy. METHODS: A comprehensive literature search was performed with the following search terms: tendinopathy, tenotomy, needling, Tenex, fasciotomy, ultrasound-guided, and percutaneous. Inclusion criteria consisted of original studies evaluating pain or function improvement after PUNT. Meta-analyses investigating standard mean differences were performed to assess the pain and function improvement. RESULTS: Thirty-five studies with 1674 participants (1876 tendons) were enrolled in this article. Of which 29 articles were included in meta-analysis and the remaining 9 articles without enough numeric data were included in descriptive analysis. PUNT significantly alleviated pain with the standard mean difference of 2.5 (95% CI: 2.0-3.0; p < 0.05), 2.2 (95% confidence interval (CI): 1.8-2.7; p < 0.05), and 3.6 (95% CI: 2.8-4.5; p < 0.05) points in short-term, intermediate-term, and long-term follow-up intervals, respectively. It was also associated with marked improvement in function with 1.4 (95% CI: 1.1-1.8; p < 0.05), 1.8 (95% CI: 1.3-2.2; p < 0.05), and 2.1 (95% CI: 1.6-2.6; p < 0.05) points, respectively in short-term, intermediate-term, and long-term follow-ups. CONCLUSION: PUNT improved pain and function at short-term intervals with persistent results on intermediate- and long-term follow-ups. PUNT can be considered an appropriate minimally invasive treatment for chronic tendinopathy with a low rate of complications and failures. CLINICAL RELEVANCE: Tendinopathy and fasciopathy are two common musculoskeletal complaints that can cause prolonged pain and disability. PUNT as a treatment option could improve pain intensity and function. KEY POINTS: • The best improvement in pain and function was achieved after the first 3 months following PUNT and was continued to the intermediate- and long-term follow-ups. • No significant difference was found between different tenotomy methods in terms of pain and function improvement. • PUNT is a minimally invasive procedure with promising results and low complication rates for treatments of chronic tendinopathy.

Photovoltaics at multi-terawatt scale: Waiting is not an option.

25% annual PV growth is possible over the next decade.

Antibiotic Practice in Patients With Acute Abdomen Admitted to a Danish Regional Hospital: A Clinical Qualitative Assurance Study.

Background Acute abdomen is often complicated by intra-abdominal infection requiring antibiotic therapy. Danish regional antibiotic guidelines emphasize the restricted use of broad-spectrum antibiotics such as cephalosporins. In this study, we aimed to evaluate antibiotic practices in relation to hospitalized patients with acute abdomen. Methodology This retrospective quality assurance study was conducted among patients admitted to the surgical emergency department at the North Denmark Regional Hospital during a four-month observation period. Data were extracted from electronic patient journals and entered in the Research Electronic Data Capture data management system for further analytical work. Results Of 331 patients, 174 (53%) were treated with antibiotics, of whom 98 (56%) had been treated with cephalosporin, 47 (27%) with benzylpenicillin and gentamicin, 22 (13%) with piperacillin/tazobactam, and seven (4%) with ciprofloxacin. Use of a cephalosporin-based antibiotic regimen was significantly more common in patients with acute appendicitis (75%) compared to other diagnostic groups, such as acute cholecystitis (57%), incarcerated hernia with strangulation (56%), acute pancreatitis (50%), and acute diverticulitis (30%). However, patients with uncomplicated diverticulitis (53%) were significantly more often treated with benzylpenicillin and gentamicin, whereas patients with complicated diverticulitis Hinchey stage 3-4 were significantly more often treated with piperacillin/tazobactam. In addition, as the severity of acute cholecystitis increased, it was more frequently treated with piperacillin/tazobactam. Conclusions The study revealed that cephalosporins are frequently used in patients hospitalized with acute abdomen. This finding conflicts with current regional antibiotic guidelines. Reinforcement of the guidelines is required as an essential measure against the development of antibiotic resistance associated with the use of cephalosporins.

Prion Propagation is Dependent on Key Amino Acids in Charge Cluster 2 within the Prion Protein.

To dissect the N-terminal residues within the cellular prion protein (PrPC) that are critical for efficient prion propagation, we generated a library of point, double, or triple alanine replacements within residues 23-111 of PrP, stably expressed them in cells silenced for endogenous mouse PrPC and challenged the reconstituted cells with four common but biologically diverse mouse prion strains. Amino acids (aa) 105-111 of Charge Cluster 2 (CC2), which is disordered in PrPC, were found to be required for propagation of all four prion strains; other residues had no effect or exhibited strain-specific effects. Replacements in CC2, including aa105-111, dominantly inhibited prion propagation in the presence of endogenous wild type PrPC whilst other changes were not inhibitory. Single alanine replacements within aa105-111 identified leucine 108 and valine 111 or the cluster of lysine 105, threonine 106 and asparagine 107 as critical for prion propagation. These residues mediate specific ordering of unstructured CC2 into ß-sheets in the infectious prion fibrils from Rocky Mountain Laboratory (RML) and ME7 mouse prion strains.

The German Lipoprotein Apheresis Registry-Summary of the ninth annual report.

During 2012-2020, 89 German apheresis centers collected retrospective and prospective observational data of 2028 patients undergoing regular lipoprotein apheresis (LA) for the German Lipoprotein Apheresis Registry (GLAR). More than 47 500 LA sessions are documented in GLAR. In 2020, all patients treated with LA showed a high immediate median reduction rate of LDL-C (68.2%, n = 1055) and Lp(a) (72.4%, n = 994). Patient data were analyzed for the incidence rate of major coronary events (MACE) 1 and 2 years before the beginning of LA treatment (y-2 and y-1) and prospectively up to 7 years on LA (y + 1 to y + 7). During the first 2 years of LA (y + 1 and y + 2), a MACE reduction of 78% was observed. Current analysis of GLAR data shows very low incidence rates of cardiovascular events in patients with high LDL-C and/or high Lp(a) levels, progressive ASCVD, and maximally tolerated lipid lowering medication regular by LA results.

IL-24 intrinsically regulates Th17 cell pathogenicity in mice.

In certain instances, Th17 responses are associated with severe immunopathology. T cell-intrinsic mechanisms that restrict pathogenic effector functions have been described for type 1 and 2 responses but are less well studied for Th17 cells. Here, we report a cell-intrinsic feedback mechanism that controls the pathogenicity of Th17 cells. Th17 cells produce IL-24, which prompts them to secrete IL-10. The IL-10-inducing function of IL-24 is independent of the cell surface receptor of IL-24 on Th17 cells. Rather, IL-24 is recruited to the inner mitochondrial membrane, where it interacts with the NADH dehydrogenase (ubiquinone) 1 α subcomplex subunit 13 (also known as Grim19), a constituent of complex I of the respiratory chain. Together, Grim19 and IL-24 promote the accumulation of STAT3 in the mitochondrial compartment. We propose that IL-24-guided mitochondrial STAT3 constitutes a rheostat to blunt extensive STAT3 deflections in the nucleus, which might then contribute to a robust IL-10 response in Th17 cells and a restriction of immunopathology in experimental autoimmune encephalomyelitis.

Experimental Validation and Deployment of Observability Applications for Monitoring of Low-Voltage Distribution Grids.

Future distribution grids will be subjected to fluctuations in voltages and power flows due to the presence of renewable sources with intermittent power generation. The advanced smart metering infrastructure (AMI) enables the distribution system operators (DSOs) to measure and analyze electrical quantities such as voltages, currents and power at each customer connection point. Various smart grid applications can make use of the AMI data either in offline or close to real-time mode to assess the grid voltage conditions and estimate losses in the lines/cables. The outputs of these applications can enable DSOs to take corrective action and make a proper plan for grid upgrades. In this paper, the process of development and deployment of applications for improving the observability of distributions grids is described, which consists of the novel deployment framework that encompasses the proposition of data collection, communication to the servers, data storage, and data visualization. This paper discussed the development of two observability applications for grid monitoring and loss calculation, their validation in a laboratory setup, and their field deployment. A representative distribution grid in Denmark is chosen for the study using an OPAL-RT real-time simulator. The results of the experimental studies show that the proposed applications have high accuracy in estimating grid voltage magnitudes and active energy losses. Further, the field deployment of the applications prove that DSOs can gain insightful information about their grids and use them for planning purposes.

Atherectomy and Drug-Coated Balloon Angioplasty for the Treatment of Long Infrapopliteal Lesions: A Randomized Controlled Trial.

BACKGROUND: Prospective, randomized, multicenter trials show no beneficial impact of drug-coated balloon (DCB) therapy alone on the technical and clinical outcomes of infrapopliteal artery lesions in comparison to plain old balloon angioplasty. The aim of this study was to evaluate the performance of directional atherectomy (DA) plus DCB angioplasty versus DCB alone in treatment of long infrapopliteal artery lesions. METHODS: We conducted a prospective, randomized, 2-center trial comparing the performance of DA+DCB and DCB alone in treatment of 80 patients with de novo infrapopliteal artery lesions. The primary study end point was the 6-month primary patency of the target lesion detected by angiography and duplex ultrasound. Secondary end points included clinically driven target vessel revascularization, amputation rates, and changes in Rutherford-Becker class at 1 year. A core laboratory provides independent analyses for all scheduled and unscheduled duplex ultrasound examinations and angiographies, and a research institute ensured independent data collection. RESULTS: The mean target lesion length was 179.7±98.2 mm. Nine patients (11.3%) died during the follow-up period. At 6 months, primary patency was 49% (n=18) with DA+DCB versus 34% (n=12) with DCB alone (P=0.241), and clinically driven target vessel revascularization was 8% (n=3) versus 14% (n=5; P=0.475), respectively. At 1 year, the target lesion revascularization rates were 30% (n=10) versus 43% (n=12; P=0.308), the median in Rutherford-Becker class was 2 (0.25­5) versus 5 (0.25­5; P=0.329), and amputation rates were 22% (n=8) versus 32% (n=11; P=0.618) in the DA+DCB group and the DCB group, respectively. CONCLUSIONS: Treatment of long infrapopliteal artery lesions with DA+DCB versus DCB alone leads to comparable clinical and technical results at 6 months and 1 year. REGISTRATION: https://www.clinicaltrials.gov; Unique identifier: NCT01763476.

Towards understanding of electrolyte degradation in lithium-mediated non-aqueous electrochemical ammonia synthesis with gas chromatography-mass spectrometry.

Lithium-mediated electrochemical ammonia synthesis (LiMEAS) in non-aqueous media is a promising technique for efficient and green ammonia synthesis. Compared to the widely used Haber-Bosch process, the method reduces CO2 emissions to zero due to the application of green hydrogen. However, the non-aqueous medium encounters the alkali metal lithium and organic components at high negative potentials of electrolysis, which leads to formation of byproducts. To assess the environmental risk of this synthesis method, standardized analytical methods towards understanding of the degradation level and consequences are needed. Here we report on the implementation of an approach to analyze the liquid electrolytes after electrochemical ammonia synthesis via high-resolution gas chromatography-mass spectrometry (GCMS). To characterize the molecular species formed after electrolysis, electron ionization high-resolution mass spectrometry (EI-MS) was applied. The fragmentation patterns enabled the elucidation of the mechanisms of byproduct formation. Several organic electrolytes were analyzed and compared both qualitatively and quantitatively to ascertain molecular composition and degradation products. It was found that the organic solvent in contact with metallic electrodeposited lithium induces solvent degradation, and the extent of this decomposition to different organic molecules depends on the organic solvent used. Our results show GCMS as a suitable technique for monitoring non-aqueous electrochemical ammonia synthesis in different organic electrolytes.

Outcomes of directional atherectomy for common femoral artery disease.

BACKGROUND: Endovascular therapy is the first-line strategy for femoropopliteal obstructive disease. However, for lesions involving the common femoral artery (CFA) surgical endarterectomy is still the gold standard. AIMS: The aim of this study was to evaluate the safety and efficacy of directional atherectomy (DA) for the treatment of CFA lesions. METHODS: A retrospective analysis of patients who underwent DA of the CFA between March 2009 and June 2017 was performed. The primary efficacy endpoint was the incidence of clinically driven target lesion revascularisation (cdTLR). Secondary endpoints included the overall procedural complication rate at 30 days, change in ankle-brachial index (ABI), and Rutherford-Becker class (RBC) during follow-up. RESULTS: This analysis included 250 patients. The mean follow-up period was 31.03±21.56 months (range 1-88, median follow-up period 25 months). The procedural complication rate including access-site complications, target lesion perforation, and outflow embolisation was 10.4% (n=26). All but one complication could be treated conservatively or endovascularly. One surgical revision was necessary. Freedom from major adverse events (death, cdTLR, myocardial infarction and major target limb amputation) at 30 days was 99.6%. The rate of cdTLR during follow-up was 13.6% (n=34). A significant improvement of the mean ABI and the RBC was observed. Multivariate logistic regression analysis revealed residual target lesion stenosis >30% (p=0.005), and heavy calcification of the target lesion (p=0.033) to be independent predictors for cdTLR. CONCLUSIONS: The use of DA for the treatment of CFA lesions leads to promising midterm results with an acceptable complication rate.

Cooling of Medial Septum Reveals Theta Phase Lag Coordination of Hippocampal Cell Assemblies.

Hippocampal theta oscillations coordinate neuronal firing to support memory and spatial navigation. The medial septum (MS) is critical in theta generation by two possible mechanisms: either a unitary "pacemaker" timing signal is imposed on the hippocampal system, or it may assist in organizing target subcircuits within the phase space of theta oscillations. We used temperature manipulation of the MS to test these models. Cooling of the MS reduced both theta frequency and power and was associated with an enhanced incidence of errors in a spatial navigation task, but it did not affect spatial correlates of neurons. MS cooling decreased theta frequency oscillations of place cells and reduced distance-time compression but preserved distance-phase compression of place field sequences within the theta cycle. Thus, the septum is critical for sustaining precise theta phase coordination of cell assemblies in the hippocampal system, a mechanism needed for spatial memory.

Do protocols for new randomised trials take previous similar trials into account? Cohort study of contemporary trial protocols.

OBJECTIVE: To investigate to what extent evidence from previous similar trials or systematic reviews was considered before conducting new trials. DESIGN: Cohort study of contemporary protocols for trials with ethical approval. METHODS: All protocols for randomised trials approved by the five ethical committees in Denmark between January 2012 and March 2013 were screened for eligibility. Included protocols were read in full to determine whether a systematic search had been conducted and references were checked to evaluate whether trial rationale and design could be challenged for not adequately considering previous evidence. To investigate whether protocols cited relevant trials, we used simple search strategies that could easily be conducted by researchers without experience with literature searches. RESULTS: Sixty-seven protocols were included. Only two (3%) of the protocols explicitly stated to have conducted a literature search and only one (1%) provided information that allowed the search to be replicated. Eleven (16%) of the protocols described trials where we found the information insufficient to judge if the trial was ethically justified, either due to a comparator that was not supported by the presented evidence (six protocols), because they did not present a rationale for conducting the trial (two protocols), or for both reasons (three protocols). For eight (12%) of the protocols, our search identified trials that could have been relevant to cite as justification. CONCLUSIONS: While most protocols seem to adequately consider existing evidence, a substantial minority of trials might lack a sufficient evidence base. Very few trials seemed to have been based on a literature search which makes it impossible to know whether all relevant previous trials had been considered. Rules for ethical approval should include requirements for systematic literature searches to ensure that research participants are not exposed to sub-optimal treatments or unnecessary harms as well as to reduce research waste.

A New Cell Model for Investigating Prion Strain Selection and Adaptation.

Prion diseases are fatal neurodegenerative diseases that affect humans and animals. Prion strains, conformational variants of misfolded prion proteins, are associated with distinct clinical and pathological phenotypes. Host-strain interactions result in the selective damage of distinct brain areas and they are responsible for strain selection and/or adaptation, but the underlying molecular mechanisms are unknown. Prion strains can be distinguished by their cell tropism in vivo and in vitro, which suggests that susceptibility to distinct prion strains is determined by cellular factors. The neuroblastoma cell line PK1 is refractory to the prion strain Me7, but highly susceptible to RML. We challenged a large number of clonal PK1 lines with Me7 and successfully selected highly Me7-susceptible subclones (PME) to investigate whether the prion strain repertoire of PK1 can be expanded. Notably, the Me7-infected PME clones were more protease-resistant when compared to RML-infected PME clones, which suggested that cell-adapted Me7 and RML are distinct prion strains. Strikingly, Me7-refractory cells, including PK1 and astrocytes in cortico-hippocampal cultures, are highly susceptible to prions, being derived from homogenates of Me7-infected PME cells, suggesting that the passage of Me7 in PME cells leads to an extended host range. Thus, PME clones represent a compelling cell model for strain selection and adaptation.