Evaluating protein cross-linking as a therapeutic strategy to stabilize SOD1 variants in a mouse model of familial ALS.

Mutations in the gene encoding Cu-Zn superoxide dismutase 1 (SOD1) cause a subset of familial amyotrophic lateral sclerosis (fALS) cases. A shared effect of these mutations is that SOD1, which is normally a stable dimer, dissociates into toxic monomers that seed toxic aggregates. Considerable research effort has been devoted to developing compounds that stabilize the dimer of fALS SOD1 variants, but unfortunately, this has not yet resulted in a treatment. We hypothesized that cyclic thiosulfinate cross-linkers, which selectively target a rare, 2 cysteine-containing motif, can stabilize fALS-causing SOD1 variants in vivo. We created a library of chemically diverse cyclic thiosulfinates and determined structure-cross-linking-activity relationships. A pre-lead compound, "S-XL6," was selected based upon its cross-linking rate and drug-like properties. Co-crystallographic structure clearly establishes the binding of S-XL6 at Cys 111 bridging the monomers and stabilizing the SOD1 dimer. Biophysical studies reveal that the degree of stabilization afforded by S-XL6 (up to 24°C) is unprecedented for fALS, and to our knowledge, for any protein target of any kinetic stabilizer. Gene silencing and protein degrading therapeutic approaches require careful dose titration to balance the benefit of diminished fALS SOD1 expression with the toxic loss-of-enzymatic function. We show that S-XL6 does not share this liability because it rescues the activity of fALS SOD1 variants. No pharmacological agent has been proven to bind to SOD1 in vivo. Here, using a fALS mouse model, we demonstrate oral bioavailability; rapid engagement of SOD1G93A by S-XL6 that increases SOD1G93A's in vivo half-life; and that S-XL6 crosses the blood-brain barrier. S-XL6 demonstrated a degree of selectivity by avoiding off-target binding to plasma proteins. Taken together, our results indicate that cyclic thiosulfinate-mediated SOD1 stabilization should receive further attention as a potential therapeutic approach for fALS.

Revisiting the Roles of Catalytic Residues in Human Ornithine Transcarbamylase.

Human ornithine transcarbamylase (hOTC) is a mitochondrial transferase protein involved in the urea cycle and is crucial for the conversion of toxic ammonia to urea. Structural analysis coupled with kinetic studies of Escherichia coli, rat, bovine, and other transferase proteins has identified residues that play key roles in substrate recognition and conformational changes but has not provided direct evidence for all of the active residues involved in OTC function. Here, computational methods were used to predict the likely active residues of hOTC; the function of these residues was then probed with site-directed mutagenesis and biochemical characterization. This process identified previously reported active residues, as well as distal residues that contribute to activity. Mutation of active site residue D263 resulted in a substantial loss of activity without a decrease in protein stability, suggesting a key catalytic role for this residue. Mutation of predicted second-layer residues H302, K307, and E310 resulted in significant decreases in enzymatic activity relative to that of wild-type (WT) hOTC with respect to l-ornithine. The mutation of fourth-layer residue H107 to produce the hOTC H107N variant resulted in a 66-fold decrease in catalytic efficiency relative to that of WT hOTC with respect to carbamoyl phosphate and a substantial loss of thermal stability. Further investigation identified H107 and to a lesser extent E98Q as key residues involved in maintaining the hOTC quaternary structure. This work biochemically demonstrates the importance of D263 in hOTC catalytic activity and shows that residues remote from the active site also play key roles in activity.

Coverage for evidence-based cancer survivorship care services.

PURPOSE: The American Society of Clinical Oncology Cancer Survivorship Committee established a task force to determine which survivorship care services were being denied by public and private payers for coverage and reimbursement. METHODS: A quantitative survey instrument was developed to determine the clinical practice-reported rates of coverage denials for evidence-based cancer survivorship care services. Additionally, qualitative interviews were conducted to understand whether coverage denials were based on payer policies, cost-sharing, or prior authorization. RESULTS: Of 122 respondents from 50 states, respondents reported that coverage denials were common ("always," "most of the time," or "some of the time") for maintenance therapies, screening for new primary cancers or cancer recurrence. Respondents reported that denials in coverage for maintenance therapies were highest for immunotherapy (41.74%) and maintenance chemotherapy (40.17%). Coverage denials for new primary cancer screenings were highest for Hodgkin lymphoma survivors needing a PET/CT scan (49.04%) and breast cancer survivors at a high risk of recurrence who needed an MRI (63.46%), respectively. More than half of survey respondents reported denials for symptom management and supportive care services. Fertility services, dental services when indicated, and mental health services were denied "always" or "most of the time" 23.1%, 22.5%, and 12.8%, respectively. Respondents reported they often had a process in place to automatically appeal denials for evidence-based services. The denial process, however, resulted in greater stress for the patient and provider. CONCLUSION: Our study demonstrates that additional advocacy with payers is needed to ensure that reimbursement policies are consistent with evidence-based survivorship care services.

Controlled Stiffness of Direct-Write, Near-Field Electrospun Gelatin Fibers Generates Differences in Tenocyte Morphology and Gene Expression.

Tendinopathy is a leading cause of mobility issues. Currently, the cell-matrix interactions involved in the development of tendinopathy are not fully understood. In vitro tendon models provide a unique tool for addressing this knowledge gap as they permit fine control over biochemical, micromechanical, and structural aspects of the local environment to explore cell-matrix interactions. In this study, direct-write, near-field electrospinning of gelatin solution was implemented to fabricate micron-scale fibrous scaffolds that mimic native collagen fiber size and orientation. The stiffness of these fibrous scaffolds was found to be controllable between 1 MPa and 8 MPa using different crosslinking methods (EDC, DHT, DHT+EDC) or through altering the duration of crosslinking with EDC (1 h to 24 h). EDC crosslinking provided the greatest fiber stability, surviving up to 3 weeks in vitro. Differences in stiffness resulted in phenotypic changes for equine tenocytes with low stiffness fibers (∼1 MPa) promoting an elongated nuclear aspect ratio while those on high stiffness fibers (∼8 MPa) were rounded. High stiffness fibers resulted in the upregulation of matrix metalloproteinase (MMPs) and proteoglycans (possible indicators for tendinopathy) relative to low stiffness fibers. These results demonstrate the feasibility of direct-written gelatin scaffolds as tendon in vitro models and provide evidence that matrix mechanical properties may be crucial factors in cell-matrix interactions during tendinopathy formation.

Interspecies Transmission of Swine Influenza A Viruses and Human Seasonal Vaccine-Mediated Protection Investigated in Ferret Model.

We investigated the infection dynamics of 2 influenza A(H1N1) virus isolates from the swine 1A.3.3.2 (pandemic 2009) and 1C (Eurasian, avian-like) lineages. The 1C-lineage virus, A/Pavia/65/2016, although phylogenetically related to swine-origin viruses, was isolated from a human clinical case. This strain infected ferrets, a human influenza model species, and could be transmitted by direct contact and, less efficiently, by airborne exposure. Infecting ferrets and pigs (the natural host) resulted in mild or inapparent clinical signs comparable to those observed with 1A.3.3.2-lineage swine-origin viruses. Both H1N1 viruses could infect pigs and were transmitted to cohoused ferrets. Ferrets vaccinated with a human 2016-17 seasonal influenza vaccine were protected against infection with the antigenically matched 1A pandemic 2009 virus but not against the swine-lineage 1C virus. Our results reaffirm the need for continuous influenza A virus surveillance in pigs and identification of candidate human vaccine viruses.

Do discussions of financial burdens decrease long-term financial toxicity in adolescent and young adult cancer survivors?

PURPOSE: This study aims to evaluate the associations between patient-provider cost discussions with patient-reported out-of-pocket (OOP) spending and long-term financial toxicity (FT) among adolescent and young adult (AYA; 15-39 years old) cancer survivors. METHODS: Using a cross-sectional survey, we assessed the themes and quality of patient discussions with providers about financial needs and general survivorship preparation, quantified patients' levels of FT, and evaluated patient-reported OOP spending. We determined the association between cancer treatment cost discussion and FT using multivariable analysis. In a subset of survivors (n = 18), we conducted qualitative interviews and used thematic analysis to characterize responses. RESULTS: Two hundred forty-seven AYA survivors completed the survey at a mean of 7 years post treatment and with a median COST score of 13. 70% of AYA survivors did not recall having any cost discussion about their cancer treatment with a provider. Having any cost discussion with a provider was associated with decreased FT (ß = 3.00; p = 0.02) but not associated with reduced OOP spending (χ2 = 3.77; p = 0.44). In a second adjusted model, with OOP spending included as a covariate, OOP spending was a significant predictor of FT (ß = - 1.40; p = 0.002). Key qualitative themes included survivors' frustration about the lack of communication related to financial issues throughout treatment and in survivorship, feeling unprepared, and reluctance to seek help. CONCLUSION: AYA patients are not fully informed about the costs of cancer care and FT; the dearth of cost discussions between patients and providers may represent a missed opportunity to reduce costs.

Periorbital Necrotizing Sweet's Syndrome: A Case Report.

Sweet's syndrome (acute febrile neutrophilic dermatosis) is an uncommon inflammatory condition most often associated with painful skin lesions of the head, neck, and upper extremities. To the authors' knowledge, this case report is the only published record of the necrotizing clinical variant of Sweet's syndrome in the periorbital space. This case follows a 91-year-old female who presented with generalized cutaneous eruptions of tender erythematous plaques, including a necrotic plaque of the left upper eyelid, and pancytopenia. A biopsy of an inner thigh lesion was consistent with Sweet's syndrome. Initially diagnosed with preseptal cellulitis, the patient experienced marked clinical improvement with corticosteroids. This, coupled with the histopathologic findings of her thigh biopsy and the absence of eyelid margins, led to the diagnosis of periorbital necrotizing Sweet's syndrome. Although cases of Sweet's syndrome in the periorbital region are rare, these diagnoses should not be overlooked and may be critical to patient care.

Subclinical hepatitis E virus infection in laboratory ferrets in the UK.

Ferrets are widely used for experimental modelling of viral infections. However, background disease in ferrets could potentially confound intended experimental interpretation. Here we report the detection of a subclinical infection of ferret hepatitis E virus (FRHEV) within a colony sub-group of female laboratory ferrets that had been enrolled on an experimental viral infection study (non-hepatitis). Lymphoplasmacytic cuffing of periportal spaces was identified on histopathology but was negative for the RNA and antigens of the administered virus. Follow-up viral metagenomic analysis conducted on liver specimens revealed sequences attributed to FRHEV and these were confirmed by reverse-transcriptase polymerase chain reaction. Further genomic analysis revealed contiguous sequences spanning 79-95 % of the FRHEV genome and that the sequences were closely related to those reported previously in Europe. Using in situ hybridization by RNAScope, we confirmed the presence of HEV-specific RNA in hepatocytes. The HEV open reading frame 2 (ORF2) protein was also detected by immunohistochemistry in the hepatocytes and the biliary canaliculi. In conclusion, the results of our study provide evidence of background infection with FRHEV in laboratory ferrets. As this infection can be subclinical, we recommend routine monitoring of ferret populations using virological and liver function tests to avoid incorrect causal attribution of any liver disease detected in in vivo studies.

Stereoselective Synthesis of ß-Glycinamide Ribonucleotide.

A diastereoselective synthesis of the ß-anomer of glycinamide ribonucleotide (ß-GAR) has been developed. The synthesis was accomplished in nine steps from D-ribose and occurred in 5% overall yield. The route provided material on the multi-milligram scale. The synthetic ß-GAR formed was remarkably resistant to anomerization both in solution and as a solid.

Economic distress, financial toxicity, and medical cost-coping in young adult cancer survivors during the COVID-19 pandemic: Findings from an online sample.

BACKGROUND: Young adult (YA) cancer survivors are at risk for financial toxicity during and after cancer treatment. Financial toxicity has been associated with medical-related cost-coping behaviors such as skipping or delaying treatment. The coronavirus disease 2019 (COVID-19) pandemic has resulted in dire economic consequences that may worsen financial hardship among young survivors. METHODS: This was a cross-sectional survey; data collection occurred online. A convenience sample was recruited through YA cancer advocacy groups and social media. Negative economic events associated with the COVID-19 pandemic (eg, income loss, increased debt, and decreased job security) and medical-related cost-coping were documented. A validated measure assessed cancer-related financial toxicity. RESULTS: Participants (N = 212) had a mean age of 35.3 years at survey completion and a mean age of 27.4 years at diagnosis. Financial toxicity (mean, 14.0; SD, 9.33) was high. Two-thirds of the sample experienced at least 1 negative economic event during COVID-19, and 71% engaged in at least 1 medical cost-coping behavior. Cost-coping and pandemic-related negative economic events were significantly correlated with cancer-related financial toxicity. In multivariable analyses, pandemic-related negative economic events and financial toxicity were associated with cost-coping. CONCLUSIONS: Acute negative economic events associated with the COVID-19 pandemic may exacerbate cancer-related financial toxicity and overall financial hardship among YAs and lead to cost-coping behaviors that can compromise survivorship care and health outcomes. Multilevel, systematic interventions are needed to address the financial needs of YA survivors after the global pandemic.

"Creating a family after battling cancer is exhausting and maddening": Exploring real-world experiences of young adult cancer survivors seeking financial assistance for family building after treatment.

OBJECTIVE: Young adult (YA) cancer survivors who received gonadotoxic therapy are at risk for impaired fertility and/or childbearing difficulties. This study explored the experiences and financial concerns of survivors pursuing family building through assisted reproductive technology (ART) and adoption. METHODS: Retrospective study of data collected from grant applications for financial assistance with family building. Grounded theory methodology using an inductive data-driven approach guided qualitative data analysis. RESULTS: Participants (N = 46) averaged 32 years old (SD = 3.4) were primarily female (81%) and married/partnered (83%). Four main themes were identified representing the (1) emotional experiences and (2) financial barriers to family building after cancer, (3) perceived impact on partners, and (4) disrupted life trajectory. Negative emotions were pervasive but were balanced with hope and optimism that parenthood would be achieved. Still, the combination of high ART/adoption costs, the financial impact of cancer, and limited sources for support caused extreme financial stress. Further, in the face of these high costs, many survivors reported worry and guilt about burdening partners, particularly as couples failed to meet personal and societal expectations for parenthood timelines. CONCLUSION: After cancer, YAs face numerous psychosocial and financial difficulties in their pursuits of family building when ART/adoption is needed to achieve parenthood. Survivors interested in future children may benefit from follow-up fertility counseling post-treatment including discussion of ART options, surrogacy, and adoption, as appropriate, and potential barriers. Planning for the financial cost and burden in particular may help to avoid or mitigate financial stress later on.

Health systems' "surge capacity": state of the art and priorities for future research.

CONTEXT: Over the past decade, a number of high-impact natural hazard events, together with the increased recognition of pandemic risks, have intensified interest in health systems' ability to prepare for, and cope with, "surges" (sudden large-scale escalations) in treatment needs. In this article, we identify key concepts and components associated with this emerging research theme. We consider the requirements for a standardized conceptual framework for future research capable of informing policy to reduce the morbidity and mortality impacts of such incidents. Here our objective is to appraise the consistency and utility of existing conceptualizations of health systems' surge capacity and their components, with a view to standardizing concepts and measurements to enable future research to generate a cumulative knowledge base for policy and practice. METHODS: A systematic review of the literature on concepts of health systems' surge capacity, with a narrative summary of key concepts relevant to public health. FINDINGS: The academic literature on surge capacity demonstrates considerable variation in its conceptualization, terms, definitions, and applications. This, together with an absence of detailed and comparable data, has hampered efforts to develop standardized conceptual models, measurements, and metrics. Some degree of consensus is evident for the components of surge capacity, but more work is needed to integrate them. The overwhelming concentration in the United States complicates the generalizability of existing approaches and findings. CONCLUSIONS: The concept of surge capacity is a useful addition to the study of health systems' disaster and/or pandemic planning, mitigation, and response, and it has far-reaching policy implications. Even though research in this area has grown quickly, it has yet to fulfill its potential to generate knowledge to inform policy. Work is needed to generate robust conceptual and analytical frameworks, along with innovations in data collection and methodological approaches that enhance health systems' readiness for, and response to, unpredictable high-consequence surges in demand.

Soil versus atmospheric drought: A test case of plant functional trait responses.

Climate change alters mean global surface temperatures, precipitation regimes, and atmospheric moisture. Resultant drought affects the composition and diversity of terrestrial ecosystems worldwide. To date, there have been no assessments of the combined impacts of reduced precipitation and atmospheric drying on functional trait distributions of any species in an outdoor experiment. Here, we examined whether soil and atmospheric drought affected the functional traits of a focal grass species (Poa secunda) growing in monoculture and eight-species grass communities in outdoor mesocosms. We focused on specific leaf area (SLA), leaf area, stomatal density, root:shoot ratio, and fine root:coarse root ratio responses. Leaf area and overall growth were reduced with soil drying. Root:shoot ratio only increased for P. secunda growing in monoculture under combined atmospheric and soil drought. Plant energy allocation strategy (measured using principal components) differed when P. secunda was grown in combined soil and atmospheric drought conditions compared with soil drought alone. Given a lack of outdoor manipulations of this kind, our results emphasize the importance of atmospheric drying on functional trait responses more broadly. We suggest that drought methods focused purely on soil water inputs may be imprecisely predicting drought effects on other terrestrial organisms as well (other plants, arthropods, and higher trophic levels).

"Both a life saver and totally shameful": young adult cancer survivors' perceptions of medical crowdfunding.

PURPOSE: Young adults (YAs) diagnosed with cancer face high financial burden at a time in their lives when they are financially vulnerable. Some turn to medical crowdfunding, that is, using social media and other means to raise funds or resources to offset medical and usual life expenses. Major research gaps exist regarding the experiences of those who pursued crowdfunding. Thus, the study purpose was to describe the perceptions of, and experiences with, medical crowdfunding among a sample of YA cancer survivors. METHODS: In February 2021, we distributed an online survey to YAs with a history of a cancer diagnosis, who had received grants from an organization that offers financial assistance. We calculated descriptive statistics on the crowdfunding sample and employed thematic analysis to analyze the open-ended questions. RESULTS: In this sample (N = 113), 46 YA cancer survivors had engaged in medical crowdfunding and shared their perceptions and experiences. Our central theme, "The Crowdfunding Compromise" captures the trade-offs participants faced, which included subthemes of "crowdfunding as useful/helpful," "factors associated with crowdfunding success," and "questioning the why?". CONCLUSIONS: Among YA cancer survivors, medical crowdfunding brings shame and stigma in addition to financial support. YA cancer survivors demonstrate resilience in their attempts to find individual solutions to financial problems created by unchecked health care costs, the US health insurance infrastructure, and lack of legislation. IMPLICATIONS FOR CANCER SURVIVORS: This study fills an important gap in understanding individual-level crowdfunding experiences. Implications include system-level approaches to addressing cancer-related financial burden and potential worsening of existing disparities through medical crowdfunding.

The long-term financial experiences of adolescent and young adult cancer survivors.

BACKGROUND: Cancer-related financial hardship can negatively impact financial well-being and may prevent adolescent and young adult (AYA) cancer survivors (ages 15-39) from gaining financial independence. This analysis explored the financial experiences following diagnosis with cancer among AYA survivors. METHODS: We conducted a cross-sectional, anonymous survey of a national sample of AYAs recruited online. The Comprehensive Score for Financial Toxicity (COST) and InCharge Financial Distress/Financial Well-Being Scale (IFDFW) assessed financial hardship (cancer-related and general, respectively), and respondents reported related financial consequences and financial coping behaviors (both medical and non-medical). RESULTS: Two hundred sixty-seven AYA survivors completed the survey (mean 8.3 years from diagnosis). Financial hardship was high: mean COST score was 13.7 (moderate-to-severe financial toxicity); mean IFDFW score was 4.3 (high financial stress). Financial consequences included post-cancer credit score decrease (44%), debt collection contact (39%), spending more than 10% of income on medical expenses (39%), and lacking money for basic necessities (23%). Financial coping behaviors included taking money from savings (55%), taking on credit card debt (45%), putting off major purchases (45%), and borrowing money (42%). In logistic regression models, general financial distress was associated with increased odds of experiencing financial consequences and engaging in both medical- and non-medical-related financial coping behaviors. DISCUSSION: AYA survivors face long-term financial hardship after cancer treatment, which impacts multiple domains, including their use of healthcare and their personal finances. Interventions are needed to provide AYAs with tools to navigate financial aspects of the healthcare system; connect them with resources; and create systems-level solutions to address healthcare affordability. IMPLICATIONS FOR CANCER SURVIVORS: Survivorship care providers, particularly those who interact with AYA survivors, must be attuned to the unique risk for financial hardships facing this population and make efforts to increase access available interventions.

Using Real-World Data to Explore the Impact of One-Time Financial Grants Among Young Adult Cancer Survivors.

Young adult (YA) cancer survivors experience worse financial outcomes than older survivors. This analysis used data from Expect Miracles Foundation to explore the impact of one-time financial grants on financial well-being and access to health care. Among 300 respondents, the average grant was $1526 (standard deviation = $587; range $300-$3000). Respondents reported improved ability to pay expenses (t = 4.45, p < 0.001), increased financial decision-making power (t = 2.79, p = 0.06), decreased medical debt impact (t = 2.1, p = 0.04), improved transportation access (t = 2.38, p = 0.02), and fewer challenges in accessing care (t = 3.0, p = 0.005) 6 months after receiving a financial grant. Financial assistance offers YAs an opportunity to meet medical and nonmedical expenses.

Chronic Quadriceps Tendon Ruptures: Primary Repair of Quadriceps Via Bioaugmentation and Patellar Tendon Lengthening.

Quadriceps tendon ruptures are devastating injuries that impair the extensor mechanism of the knee. Complete tears require prompt surgical intervention in order to ensure optimal clinical outcomes. Chronic, neglected ruptures- marked by severe extensor lag, muscular atrophy, and tendon retraction- are difficult to treat. Further, severe patella baja complicates surgical planning. While there is no consensus on optimal treatment for these injuries, many different techniques have been proposed. Unlike many of these approaches, our technique focuses on restoration of patellar height via patellar tendon lengthening. Once patellar height is restored, quadriceps tendon repair can be performed using the native quadriceps tendon. Both the patellar tendon lengthening and the quadriceps tendon repair are augmented with bioinductive implants to ensure optimal healing environments, enabling us to reestablish native extensor mechanism function.

Using big data for evaluating development outcomes: A systematic map.

Background: Policy makers need access to reliable data to monitor and evaluate the progress of development outcomes and targets such as sustainable development outcomes (SDGs). However, significant data and evidence gaps remain. Lack of resources, limited capacity within governments and logistical difficulties in collecting data are some of the reasons for the data gaps. Big data-that is digitally generated, passively produced and automatically collected-offers a great potential for answering some of the data needs. Satellite and sensors, mobile phone call detail records, online transactions and search data, and social media are some of the examples of big data. Integrating big data with the traditional household surveys and administrative data can complement data availability, quality, granularity, accuracy and frequency, and help measure development outcomes temporally and spatially in a number of new ways.The study maps different sources of big data onto development outcomes (based on SDGs) to identify current evidence base, use and the gaps. The map provides a visual overview of existing and ongoing studies. This study also discusses the risks, biases and ethical challenges in using big data for measuring and evaluating development outcomes. The study is a valuable resource for evaluators, researchers, funders, policymakers and practitioners in their effort to contributing to evidence informed policy making and in achieving the SDGs. Objectives: Identify and appraise rigorous impact evaluations (IEs), systematic reviews and the studies that have innovatively used big data to measure any development outcomes with special reference to difficult contexts. Search Methods: A number of general and specialised data bases and reporsitories of organisations were searched using keywords related to big data by an information specialist. Selection Criteria: The studies were selected on basis of whether they used big data sources to measure or evaluate development outcomes. Data Collection and Analysis: Data collection was conducted using a data extraction tool and all extracted data was entered into excel and then analysed using Stata. The data analysis involved looking at trends and descriptive statistics only. Main Results: The search yielded over 17,000 records, which we then screened down to 437 studies which became the foundation of our systematic map. We found that overall, there is a sizable and rapidly growing number of measurement studies using big data but a much smaller number of IEs. We also see that the bulk of the big data sources are machine-generated (mostly satellites) represented in the light blue. We find that satellite data was used in over 70% of the measurement studies and in over 80% of the IEs. Authors' Conclusions: This map gives us a sense that there is a lot of work being done to develop appropriate measures using big data which could subsequently be used in IEs. Information on costs, ethics, transparency is lacking in the studies and more work is needed in this area to understand the efficacies related to the use of big data. There are a number of outcomes which are not being studied using big data, either due to the lack to applicability such as education or due to lack of awareness about the new methods and data sources. The map points to a number of gaps as well as opportunities where future researchers can conduct research.

Intranasal Infection of Ferrets with SARS-CoV-2 as a Model for Asymptomatic Human Infection.

Ferrets were experimentally inoculated with SARS-CoV-2 (severe acute respiratory syndrome (SARS)-related coronavirus 2) to assess infection dynamics and host response. During the resulting subclinical infection, viral RNA was monitored between 2 and 21 days post-inoculation (dpi), and reached a peak in the upper respiratory cavity between 4 and 6 dpi. Viral genomic sequence analysis in samples from three animals identified the Y453F nucleotide substitution relative to the inoculum. Viral RNA was also detected in environmental samples, specifically in swabs of ferret fur. Microscopy analysis revealed viral protein and RNA in upper respiratory tract tissues, notably in cells of the respiratory and olfactory mucosae of the nasal turbinates, including olfactory neuronal cells. Antibody responses to the spike and nucleoprotein were detected from 21 dpi, but virus-neutralizing activity was low. A second intranasal inoculation (re-exposure) of two ferrets after a 17-day interval did not produce re-initiation of viral RNA shedding, but did amplify the humoral response in one animal. Therefore, ferrets can be experimentally infected with SARS-CoV-2 to model human asymptomatic infection.

Additional guidance on protecting on-site personnel from the excessive risks of a radiation accident.

Advice was published in 2005 (NRPB 2005 Doc. NRPB 16 1-29) to provide a framework for the protection of on-site personnel who are not involved in mitigating actions in the event of a radiation accident. Such persons could include employees of the site operator, contractors and visitors. Following on from this advice, the HPA has developed additional on-site protection guidance (Watson et al 2007 Report to HSE) (the guidance produced by Watson et al (2007) was written as a commercial contract report for the Health and Safety Executive. Parties who have relevant interest in this guidance, or who wish to comment on it, can request a copy from the HPA). The issues discussed are protection of the unborn child, measures to protect against serious deterministic injury and high individual risk of stochastic effects, implications of off-site and public exposure considerations, and development of on-site neighbouring areas. In each case particular thought is required to ensure that protective measures are efficient and do not lead to any discontinuities in the level of protection offered. Although not formal HPA advice, the new guidance is intended to aid discussions between operators and regulators.