Impact of different hand-drying methods on surrounding environment: aerosolization of virus and bacteria, and transfer to surfaces

BACKGROUND

In recent years, hand drying has been highlighted as a key step in appropriate hand hygiene, as moisture on hands can increase the transfer of micro-organisms from hands to surfaces and vice versa.

AIM

To understand bacterial and viral aerosolization following hand drying, and study the transfer of micro-organisms from hands to surfaces after drying using different methods.

METHODS

Groups of five volunteers had their hands pre-washed with soap, rinsed and dried, then inoculated with a concentrated mixture of Pseudomonas fluorescens and MS2 bacteriophage. Volunteers entered an empty washroom, one at a time, and rinsed their hands with water or washed their hands with soap prior to drying with a jet dryer or paper towels. Each volunteer applied one hand successively to various surfaces, while their other hand was sampled using the glove juice method. Both residual bacteria and viruses were quantified from the washroom air, surface swabs and hand samples.

FINDINGS

P. fluorescens and MS2 bacteriophages were rarely aerosolized while drying hands for any of the drying methods studied. Results also showed limited, and similar, transfer of both micro-organisms studied on to surfaces for all drying methods.

CONCLUSION

The use of jet dryers or paper towels produces low levels of aerosolization when drying hands in a washroom. Similarly, all drying methods result in low transfer to surfaces. While the coronavirus disease 2019 pandemic raised concerns regarding public washrooms, this study shows that all methods tested are hygienic solutions for dry washed hands.

Effects of management objectives and rules on marine conservation outcomes

Understanding the relative effectiveness and enabling conditions of different area-based management tools is essential for supporting efforts that achieve positive biodiversity outcomes as area-based conservation coverage increases to meet newly set international targets. We used data from a coastal social-ecological monitoring program in 6 Indo-Pacific countries to analyze whether social, ecological, and economic objectives and specific management rules (temporal closures, fishing gear-specific, species-specific restrictions) were associated with coral reef fish biomass above sustainable yield levels across different types of area-based management tools (i.e., comparing those designated as marine protected areas [MPAs] with other types of area-based management). All categories of objectives, multiple combinations of rules, and all types of area-based management had some sites that were able to sustain high levels of reef fish biomass-a key measure for coral reef functioning-compared with reference sites with no area-based management. Yet, the same management types also had sites with low biomass. As governments advance their commitments to the Kunming-Montreal Global Biodiversity Framework and the target to conserve 30% of the planet's land and oceans by 2030, we found that although different types of management can be effective, most of the managed areas in our study regions did not meet criteria for effectiveness. These findings underscore the importance of strong management and governance of managed areas and the need to measure the ecological impact of area-based management rather than counting areas because of their designation.

Factor VIII antibody immune complexes modulate the humoral response to factor VIII in an epitope-dependent manner

Introduction

Soluble antigens complexed with immunoglobulin G (IgG) antibodies can induce robust adaptive immune responses in vitro and in animal models of disease. Factor VIII immune complexes (FVIII-ICs) have been detected in individuals with hemophilia A and severe von Willebrand disease following FVIII infusions. Yet, it is unclear if and how FVIII-ICs affect antibody development over time.

Methods

In this study, we analyzed internalization of FVIII complexed with epitope-mapped FVIII-specific IgG monoclonal antibodies (MAbs) by murine bone marrow-derived dendritic cells (BMDCs) in vitro and antibody development in hemophilia A (FVIII-/-) mice injected with FVIII-IC over time.

Results

FVIII complexed with 2-116 (A1 domain MAb), 2-113 (A3 domain MAb), and I55 (C2 domain MAb) significantly increased FVIII uptake by BMDC but only FVIII/2-116 enhanced antibody titers in FVIII-/- mice compared to FVIII alone. FVIII/4A4 (A2 domain MAb) showed similar FVIII uptake by BMDC to that of isolated FVIII yet significantly increased antibody titers when injected in FVIII-/- mice. Enhanced antibody responses observed with FVIII/2-116 and FVIII/4A4 complexes in vivo were abrogated in the absence of the FVIII carrier protein von Willebrand factor.

Conclusion

These findings suggest that a subset of FVIII-IC modulates the humoral response to FVIII in an epitope-dependent manner, which may provide insight into the antibody response observed in some patients with hemophilia A.

Qualitative interviews to understand methods and systems used to collect ethnicity information in health administrative data sources in England

Background: This article is one of a series aiming to inform analytical methods to improve comparability of estimates of ethnic health disparities based on different sources. This article explores the quality of ethnicity data and identifies potential sources of bias when ethnicity information is collected in three key NHS data sources. Future research can build on these findings to explore analytical methods to mitigate biases. Methods: Thematic analysis of semi-structured qualitative interviews to explore potential sources of error and bias in the process of collecting ethnicity information across three NHS data sources: General Practice Extraction Service (GPES) Data for Pandemic Planning and Research (GDPPR), Hospital Episode Statistics (HES) and Improving Access to Psychological Therapies (IAPT). The study included feedback from 22 experts working on different aspects of health admin data collection for England (including staff from NHS Digital, IT system suppliers and relevant healthcare service providers). Results: Potential sources of error and bias were identified across data collection, data processing and quality assurance processes. Similar issues were identified for all three sources. Our analysis revealed three main themes which can result in bias and inaccuracies in ethnicity data recorded: data infrastructure challenges, human challenges, and institutional challenges. Conclusions: Findings highlighted that analysts using health admin data should be aware of the main sources of potential error and bias in health admin data, and be mindful that the main sources of error identified are more likely to affect the ethnicity data for ethnic minority groups. Where possible, analysts should describe and seek to account for this bias in their research.

Integrating larval connectivity into the marine conservation decision-making process across spatial scales

Larval dispersal connectivity is typically integrated into spatial conservation decisions at regional or national scales, but implementing agencies struggle with translating these methods to local scales. We used larval dispersal connectivity at regional (hundreds of kilometers) and local (tens of kilometers) scales to aid in design of networks of no-take reserves in Southeast Sulawesi, Indonesia. We used Marxan with Connectivity informed by biophysical larval dispersal models and remotely sensed coral reef habitat data to design marine reserve networks for 4 commercially important reef species across the region. We complemented regional spatial prioritization with decision trees that combined network-based connectivity metrics and habitat quality to design reserve boundaries locally. Decision trees were used in consensus-based workshops with stakeholders to qualitatively assess site desirability, and Marxan was used to identify areas for subsequent network expansion. Priority areas for protection and expected benefits differed among species, with little overlap in reserve network solutions. Because reef quality varied considerably across reefs, we suggest reef degradation must inform the interpretation of larval dispersal patterns and the conservation benefits achievable from protecting reefs. Our methods can be readily applied by conservation practitioners, in this region and elsewhere, to integrate connectivity data across multiple spatial scales.

Comparing spatial conservation prioritization methods with site- versus spatial dependency-based connectivity

Larval dispersal is an important component of marine reserve networks. Two conceptually different approaches to incorporate dispersal connectivity into spatial planning of these networks exist, and it is an open question as to when either is most appropriate. Candidate reserve sites can be selected individually based on local properties of connectivity or on a spatial dependency-based approach of selecting clusters of strongly connected habitat patches. The first acts on individual sites, whereas the second acts on linked pairs of sites. We used a combination of larval dispersal simulations representing different seascapes and case studies of biophysical larval dispersal models in the Coral Triangle region and the province of Southeast Sulawesi, Indonesia, to compare the performance of these 2 methods in the spatial planning software Marxan. We explored the reserve design performance implications of different dispersal distances and patterns based on the equilibrium settlement of larvae in protected and unprotected areas. We further assessed different assumptions about metapopulation contributions from unprotected areas, including the case of 100% depletion and more moderate scenarios. The spatial dependency method was suitable when dispersal was limited, a high proportion of the area of interest was substantially degraded, or the target amount of habitat protected was low. Conversely, when subpopulations were well connected, the 100% depletion was relaxed, or more habitat was protected, protecting individual sites with high scores in metrics of connectivity was a better strategy. Spatial dependency methods generally produced more spatially clustered solutions with more benefits inside than outside reserves compared with site-based methods. Therefore, spatial dependency methods potentially provide better results for ecological persistence objectives over enhancing fisheries objectives, and vice versa. Different spatial prioritization methods of using connectivity are appropriate for different contexts, depending on dispersal characteristics, unprotected area contributions, habitat protection targets, and specific management objectives. Comparación entre los métodos de priorización de la conservación espacial con sitio y la conectividad espacial basada en la dependencia.

The use of rats to detect drug-resistant TB

Although detection of drug-susceptible TB by Anti-Persoonsmijnen Ontmijnende Product Ontwikkeling-trained African giant pouched rats has been known for more than a decade, the detection of drug-resistant TB (DR-TB) using rats has never been explored before. We present what we believe to be the first report on rifampicin-resistant TB (RR-TB) detected using Xpert® MTB/RIF Ultra, comparably identified by rats sniffing sputum samples from presumptive TB patients: 88% of RR-TB detected using Ultra were identified by the rats. Further evaluation of the usefulness of rats for large-scale DR-TB contact triage testing is needed, especially in low- and middle-income countries, where resources are limited.

Factors Associated with Information Breach in Healthcare Facilities: A Systematic Literature Review

This systematic review aimed to identify the factors associated with information breaches in healthcare settings. We searched electronic databases, including PubMed, Embase, Scopus, and Wiley, for all publications until March 6, 2022 (no start date restriction) and outlined the eligibility criteria framework using Population, Concept, and Context (PCC). Our search strategies yielded 2,156 results, with nine studies included in the final review. We grouped the factors attributed to data breaches into four categories: organizational, information technology (IT), professionals/employees, and clients/patients. Hospital type, hospital size (more beds), higher operationalexpenses and revenue, higher admissions and discharges, and higher Electronic Medical Record (EMR) use, being at earlier phases of EMR adoption, were associated with higher information breaches. Professional factors such as the type of personnel involved and the hospital area can potentially impact the breaches' frequency and magnitude. Patients' sociodemographic, clinical, and behavioral characteristics, such as gender and educational attainment, appear to influence the perceived breach of confidentiality in healthcare settings. Identifying different factors contributing to health information breaches is crucial to protecting healthcare organizations and patients from the devastating consequences of data breaches.

Engineering a Therapeutic Protein to Enhance the Study of Anti-Drug Immunity

The development of anti-drug antibodies represents a significant barrier to the utilization of protein-based therapies for a wide variety of diseases. While the rate of antibody formation can vary depending on the therapeutic employed and the target patient population receiving the drug, the antigen-specific immune response underlying the development of anti-drug antibodies often remains difficult to define. This is especially true for patients with hemophilia A who, following exposure, develop antibodies against the coagulation factor, factor VIII (FVIII). Models capable of studying this response in an antigen-specific manner have been lacking. To overcome this challenge, we engineered FVIII to contain a peptide (323-339) from the model antigen ovalbumin (OVA), a very common tool used to study antigen-specific immunity. FVIII with an OVA peptide (FVIII-OVA) retained clotting activity and possessed the ability to activate CD4 T cells specific to OVA323-339 in vitro. When compared to FVIII alone, FVIII-OVA also exhibited a similar level of immunogenicity, suggesting that the presence of OVA323-339 does not substantially alter the anti-FVIII immune response. Intriguingly, while little CD4 T cell response could be observed following exposure to FVIII-OVA alone, inclusion of anti-FVIII antibodies, recently shown to favorably modulate anti-FVIII immune responses, significantly enhanced CD4 T cell activation following FVIII-OVA exposure. These results demonstrate that model antigens can be incorporated into a therapeutic protein to study antigen-specific responses and more specifically that the CD4 T cell response to FVIII-OVA can be augmented by pre-existing anti-FVIII antibodies.

Neutralizing Antibodies Against Factor VIII Can Occur Through a Non-Germinal Center Pathway

Humoral immunity to factor VIII (FVIII) represents a significant challenge for the treatment of patients with hemophilia A. Current paradigms indicate that neutralizing antibodies against FVIII (inhibitors) occur through a classical CD4 T cell, germinal center (GC) dependent process. However, clinical observations suggest that the nature of the immune response to FVIII may differ between patients. While some patients produce persistent low or high inhibitor titers, others generate a transient response. Moreover, FVIII reactive memory B cells are only detectable in some patients with sustained inhibitor titers. The determinants regulating the type of immune response a patient develops, let alone how the immune response differs in these patients remains incompletely understood. One hypothesis is that polymorphisms within immunoregulatory genes alter the underlying immune response to FVIII, and thereby the inhibitor response. Consistent with this, studies report that inhibitor titers to FVIII differ in animals with the same F8 pathogenic variant but completely distinct backgrounds; though, how these genetic disparities affect the immune response to FVIII remains to be investigated. Given this, we sought to mechanistically dissect how genetics impact the underlying immune response to FVIII. In particular, as the risk of producing inhibitors is weakly associated with differences in HLA, we hypothesized that genetic factors other than HLA influence the immune response to FVIII and downstream inhibitor formation. Our data demonstrate that FVIII deficient mice encoding the same MHC and F8 variant produce disparate inhibitor titers, and that the type of inhibitor response formed associates with the ability to generate GCs. Interestingly, the formation of antibodies through a GC or non-GC pathway does not appear to be due to differences in CD4 T cell immunity, as the CD4 T cell response to an immunodominant epitope in FVIII was similar in these mice. These results indicate that genetics can impact the process by which inhibitors develop and may in part explain the apparent propensity of patients to form distinct inhibitor responses. Moreover, these data highlight an underappreciated immunological pathway of humoral immunity to FVIII and lay the groundwork for identification of biomarkers for the development of approaches to tolerize against FVIII.

Participation, not penalties: Community involvement and equitable governance contribute to more effective multiuse protected areas

Accelerating ecosystem degradation has spurred proposals to vastly expand the extent of protected areas (PAs), potentially affecting the livelihoods and well-being of indigenous peoples and local communities (IPLCs) worldwide. The benefits of multiuse PAs that elevate the role of IPLCs in management have long been recognized. However, quantitative examinations of how resource governance and the distribution of management rights affect conservation outcomes are vital for long-term sustainability. Here, we use a long-term, quasi-experimental monitoring dataset from four Indonesian marine PAs that demonstrates that multiuse PAs can increase fish biomass, but incorporating multiple governance principles into management regimes and enforcing rules equitably are critical to achieve ecological benefits. Furthermore, we show that PAs predicated primarily on enforcing penalties can be less effective than those where IPLCs have the capacity to engage in management. Our results suggest that well-governed multiuse PAs can achieve conservation objectives without undermining the rights of IPLCs.

Dolutegravir resistance in Malawi’s national HIV treatment program

Dolutegravir HIV drug resistance (HIVDR) data from Africa remain sparse. We reviewed HIVDR results of Malawians on dolutegravir-based antiretroviral therapy (November 2020–September 2021). Of 6462 eligible clients, 33 samples were submitted to South Africa, 27 were sequenced successfully, and 8 (30%) had dolutegravir HIVDR. Malawi urgently requires adequate HIVDR testing capacity.

Removal of single-site N-linked glycans on factor VIII alters binding of domain-specific monoclonal antibodies

BACKGROUND

A portion of individuals with hemophilia A develop neutralizing antibodies called inhibitors to glycoprotein factor VIII (FVIII). There are multiple risk factors that contribute to the risk of inhibitor formation. However, knowledge of the role of FVIII asparagine (N)-linked glycosylation in FVIII immunity is limited.

OBJECTIVE

To evaluate the effect of site-specific N-linked glycan removal on FVIII biochemical properties, endocytosis by murine bone marrow-derived dendritic cells (BMDCs), and antibody responses.

METHODS

Four recombinant B domain-deleted (BDD) FVIII variants with single-site amino acid substitutions to remove N-linked glycans were produced for experimental assays.

RESULTS

BDD FVIII-N41G, FVIII-N239A, FVIII-N1810A, and FVIII-N2118A with confirmed removal of N-linked glycans and similar glycosylation profiles to BDD FVIII were produced. There were no differences in thrombin activation or von Willebrand factor binding of FVIII variants compared with BDD FVIII; however, reduced FVIII expression, activity, and specific activity was observed with all variants. BDD FVIII-N41G and FVIII-N1810A had reduced uptake by BMDCs, but there were no differences in antibody development in immunized hemophilia A mice compared with BDD FVIII. Half of a repertoire of 12 domain-specific FVIII MAbs had significantly reduced binding to ≥1 FVIII variant with a 50% decrease in A1 domain MAb 2-116 binding to FVIII-N239A.

CONCLUSIONS

Modifications of FVIII N-linked glycans reduced FVIII endocytosis by BMDCs and binding of domain-specific FVIII MAbs, but did not alter de novo antibody production in hemophilia A mice, suggesting that N-glycans do not significantly contribute to inhibitor formation.

No-slip billiards with particles of variable mass distribution

Astute variations in the geometry of mathematical billiard tables have been and continue to be a source of understanding their wide range of dynamical behaviors, from regular to chaotic. Viewing standard specular billiards in the broader setting of no-slip (or rough) collisions, we show that an equally rich spectrum of dynamics can be called forth by varying the mass distribution of the colliding particle. We look at three two-parameter families of billiards varying both the geometry of the table and the particle, including as special cases examples of standard billiards demonstrating dynamics from integrable to chaotic, and show that markedly divergent dynamics may arise by changing only the mass distribution. Furthermore, for certain parameters, billiards emerge, which display unusual dynamics, including examples of full measure periodic billiards, conjectured to be nonexistent for the standard billiards in Euclidean domains.

Twenty years of change in benthic communities across the Belizean Barrier Reef

Disease, storms, ocean warming, and pollution have caused the mass mortality of reef-building corals across the Caribbean over the last four decades. Subsequently, stony corals have been replaced by macroalgae, bacterial mats, and invertebrates including soft corals and sponges, causing changes to the functioning of Caribbean reef ecosystems. Here we describe changes in the absolute cover of benthic reef taxa, including corals, gorgonians, sponges, and algae, at 15 fore-reef sites (12–15m depth) across the Belizean Barrier Reef (BBR) from 1997 to 2016. We also tested whether Marine Protected Areas (MPAs), in which fishing was prohibited but likely still occurred, mitigated these changes. Additionally, we determined whether ocean-temperature anomalies (measured via satellite) or local human impacts (estimated using the Human Influence Index, HII) were related to changes in benthic community structure. We observed a reduction in the cover of reef-building corals, including the long-lived, massive corals Orbicella spp. (from 13 to 2%), and an increase in fleshy and corticated macroalgae across most sites. These and other changes to the benthic communities were unaffected by local protection. The covers of hard-coral taxa, including Acropora spp., Montastraea cavernosa, Orbicella spp., and Porites spp., were negatively related to the frequency of ocean-temperature anomalies. Only gorgonian cover was related, negatively, to our metric of the magnitude of local impacts (HII). Our results suggest that benthic communities along the BBR have experienced disturbances that are beyond the capacity of the current management structure to mitigate. We recommend that managers devote greater resources and capacity to enforcing and expanding existing marine protected areas and to mitigating local stressors, and most importantly, that government, industry, and the public act immediately to reduce global carbon emissions.

Hypokalemia Measurement and Management in Patients With Status Asthmaticus on Continuous Albuterol

OBJECTIVE

Status asthmaticus is commonly treated in pediatric patients by using continuous albuterol, which can cause hypokalemia. The primary aim of this study was to determine if serial potassium monitoring is necessary by examining treatment frequency of hypokalemia.

METHODS

This retrospective analysis was performed in 185 pediatric patients admitted with status asthmaticus requiring continuous albuterol between 2017 and 2019. All patients were placed on intravenous fluids containing potassium. The primary outcome measure was the treatment of hypokalemia in relation to the number of laboratory draws for potassium levels. The secondary outcome measure was hypokalemia frequency and relation to the duration and initial dose of continuous albuterol.

RESULTS

Included were 156 patients with 420 laboratory draws (average, 2.7 per patient) for potassium levels. The median lowest potassium level was 3.40 mmol/L (interquartile range, 3.2-3.7). No correlation was found between initial albuterol dose and lowest potassium level (P = .52). Patients with hypokalemia had a mean albuterol time of 12.32 (SD, 15.76) hours, whereas patients without hypokalemia had a mean albuterol time of 11.50 (SD, 12.53) hours (P = .29). Potassium levels were treated 13 separate times.

CONCLUSIONS

The number of laboratory draws for potassium levels was high in our cohort, with few patients receiving treatment for hypokalemia beyond the potassium routinely added to maintenance fluids. Length of time on albuterol and dose of albuterol were not shown to increase the risk of hypokalemia. Serial laboratory measurements may be decreased to potentially reduce health care costs, pain, and anxiety surrounding needlesticks.

AB0034 PD-1 AGONISM INHIBITS ACTIVATION OF PLASMACYTOID DENDRITIC CELLS

Background:

T cell function is regulated by complex signaling networks of interconnected activators and inhibitors. Blockade of inhibitory receptors such as programmed death-1 (PD-1) has emerged as a novel treatment for multiple forms of cancer. One of the most common adverse events associated with blockade of the endogenous PD-1/PD-L1 pathway is the induction of autoimmune pathology in multiple tissues, demonstrating that PD-1 activation is necessary for normal immune homeostasis in humans (Kostine, et al., 2018). Given this body of clinical data, we sought to develop a PD-1 agonist antibody as a therapeutic approach to restore immune homeostasis in patients living with autoimmune diseases. PD-1 expression and function has been primarily described on T cells (Ishida, et al., 1992), with additional data available from several other immune cell populations (Ohaegbulam, et al., 2015).

Objectives:

To study the effect of PD-1 agonism on plasmacytoid dendritic cell (pDC) function.

Methods:

Human PBMCs stimulated with or without toll-like receptor (TLR)-9 agonist, CpG were analyzed by flow cytometry for PD-1 expression on immune cell subsets. To assess the impact of PD-1 agonist on pDC function human PBMCs were activated by CpG in the presence or absence of PD-1 agonist. Type-I interferon (IFN) levels were quantified using ELISA from culture supernatants. The expression of interferon stimulated genes was analyzed by qPCR as a measure of type-I IFN activation.

Results:

We have discovered that TLR9 activation can induce PD-1 expression on plasmacytoid dendritic cells, which has not been previously reported. Further, we have demonstrated that PD-1 agonism inhibits TLR9-mediated activation and the effector functions of plasmacytoid dendritic cells.

Conclusion:

These data suggest the potential of PD-1 as a target for regulating diseases with pathology generated by type-I IFN.

References:

[1]Ishida, Y., Agata, Y., Shihibahara, K., & Honjo, T. (1992). Induced expression of PD-1, a novel member of the immunoglobulin gene superfamily, upon programmed cell death. EMBO J., 11(11):3887-95.

[2]Kostine, M., Rouxel, L., Barnetche, T., Veillon, R., Martin, F., Dutriaux, C., . . . Schaeverbeke, T. (2018). Rheumatic disorders associated with immune checkpoint inhibitors in patients with cancer-clinical aspects and relationship with tumour response: a single-centre prospective cohort study. Annual Rheumatic Disease, 77(3):393-398.

[3]Ohaegbulam, K. C., Assal, A., Lazar-Molnar, E., Yao, Y., & Zang, X. (2015). Human cancer immunotherapy with antibodies to the PD-1 and PD-L1 pathway. Trends in Molecular Medicine, 21(1); 24-33.

Disclosure of Interests:

Ishita Banerjee Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Lindsay Edwards Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Patrick Halvey Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Salvatore Alioto Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, David Cluckley Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Caitlin Mitchell Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Christopher Cox Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Emily Lurier Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Michael Cianci Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Soumya Bengeri Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Susmita Borthakur Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Katalin Kis-Toth Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Nathan Higginson-Scott Shareholder of: Pandion Therapeutics, Consultant of: Biotech Companies, Employee of: Pandion Therapeutics, Jo Viney Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics, Kevin L. Otipoby Shareholder of: Pandion Therapeutics, Employee of: Pandion Therapeutics

Immediate impact of COVID-19 across tropical small-scale fishing communities

The volume and value of fish catches by Indonesia's small-scale fisheries have declined significantly since national government restrictions on travel and social distancing were imposed in response to the COVID-19 pandemic. Using a digital data collection system (OurFish), that records purchases by fish traders from small-scale fishers, data was collected across 82 coastal communities in Southeast Sulawesi. We found that the number of active fishers and traders declined by more than 90% after the onset of the pandemic and the average weight of catch per fishing trip increased across fishers. Although the average price per kilogram of fish declined after the pandemic began, fishers that were able to maintain fishing had on average higher catches and therefore daily catch value was maintained. High value fisheries that usually enter export supply chains were more negatively impacted compared with lower value species that are commonly sold to local markets. We interviewed 185 small scale fishers and fish traders across 20 of the 82 communities in Southeast Sulawesi province, recording the perceived level of impact on local fisheries and the fish trade, causes of this impact and proposed coping strategies. Over 50% of both fishers and fish traders believed low demand for fish from traders and a decline in the price received for fish were disrupting their lives. Approximately 75% of both male and female fishers are coping by continuing to fish, highlighting that there were few alternative livelihoods available at the time of the interviews. Our results provide key insights into the vulnerability of small-scale fishing communities to impacts of the COVID-19 pandemic.

Investigation of the correlation between college students’ success with stoichiometry subproblems and metacognitive awareness

The development of problem-solving skills — particularly with stoichiometry concepts — is paramount for succeeding in a general chemistry sequence. Key concepts related to problem solving and stoichiometry were analyzed and reported in this paper. The study analyzed retention of stoichiometry concepts over two consecutive quarters, the correlations between metacognition and success, and the correlations between the COSINE (Coding System for Investigating Subproblems and the Network) codes with the categories measured by the Metacognitive Awareness Inventory (MAI). Two cohorts, identified as the general and focus groups, were evaluated in the study. The general group (n = 39) took MAI in the Fall quarter and completed one multi-step question as a part of their regular exam. Concurrently, the focus group (n = 20) participated in a think-aloud session in which they solved six stoichiometry questions. Using a 95% confidence level, statistical differences between the fall and winter problem-solving performances were observed with the focus group. Furthermore, statistically significant correlations (using a 95% level of confidence) were observed between the MAI categories and the COSINE codes.

Catalyzing sustainable fisheries management through behavior change interventions

Small-scale fisheries are an important livelihood and primary protein source for coastal communities in many of the poorest regions in the world, yet many are overfished and thus require effective and scalable management solutions. Positive ecological and socioeconomic responses to management typically lag behind immediate costs borne by fishers from fishing pressure reductions necessary for fisheries recovery. These short-term costs challenge the long-term success of these interventions. However, social marketing may increase perceptions of management benefits before ecological and socioeconomic benefits are fully realized, driving new social norms and ultimately long-term sustainable behavior change. By conducting underwater visual surveys to quantify ecological conditions and by conducting household surveys with community members to quantify their perceptions of management support and socioeconomic conditions, we assessed the impact of a standardized small-scale fisheries management intervention that was implemented across 41 sites in Brazil, Indonesia, and the Philippines. The intervention combines TURF reserves (community-based territorial use rights for fishing coupled with no-take marine reserves) with locally tailored social-marketing behavior change campaigns. Leveraging data across 22 indicators and 4 survey types, along with data from 3 control sites, we found that ecological and socioeconomic impacts varied and that communities supported the intervention and were already changing their fishing practices. These results suggest that communities were developing new social norms and fishing more sustainably before long-term ecological and socioeconomic benefits of fisheries management materialized.

Fc Gamma Receptors and Complement Component 3 Facilitate Anti-fVIII Antibody Formation

Anti-factor VIII (fVIII) alloantibodies, which can develop in patients with hemophilia A, limit the therapeutic options and increase morbidity and mortality of these patients. However, the factors that influence anti-fVIII antibody development remain incompletely understood. Recent studies suggest that Fc gamma receptors (FcγRs) may facilitate recognition and uptake of fVIII by recently developed or pre-existing naturally occurring anti-fVIII antibodies, providing a mechanism whereby the immune system may recognize fVIII following infusion. However, the role of FcγRs in anti-fVIII antibody formation remains unknown. In order to define the influence of FcγRs on the development of anti-fVIII antibodies, fVIII was injected into WT or FcγR knockout recipients, followed by evaluation of anti-fVIII antibodies. Anti-fVIII antibodies were readily observed following fVIII injection into FcγR knockouts, with similar anti-fVIII antibody levels occurring in FcγR knockouts as detected in WT mice injected in parallel. As antibodies can also fix complement, providing a potential mechanism whereby anti-fVIII antibodies may influence anti-fVIII antibody formation independent of FcγRs, fVIII was also injected into complement component 3 (C3) knockout recipients in parallel. Similar to FcγR knockouts, C3 knockout recipients developed a robust response to fVIII, which was likewise similar to that observed in WT recipients. As FcγRs or C3 may compensate for each other in recipients only deficient in FcγRs or C3 alone, we generated mice deficient in both FcγRs and C3 to test for potential antibody effector redundancy in anti-fVIII antibody formation. Infusion of fVIII into FcγRs and C3 (FcγR × C3) double knockouts likewise induced anti-fVIII antibodies. However, unlike individual knockouts, anti-fVIII antibodies in FcγRs × C3 knockouts were initially lower than WT recipients, although anti-fVIII antibodies increased to WT levels following additional fVIII exposure. In contrast, infusion of RBCs expressing distinct alloantigens into FcγRs, C3 or FcγR × C3 knockout recipients either failed to change anti-RBC levels when compared to WT recipients or actually increased antibody responses, depending on the target antigen. Taken together, these results suggest FcγRs and C3 can differentially impact antibody formation following exposure to distinct alloantigens and that FcγRs and C3 work in concert to facilitate early anti-fVIII antibody formation.

Outcome of Weekly Carboplatin-Paclitaxel-based Definitive Chemoradiation in Oesophageal Cancer in Patients Not Considered to be Suitable for Platinum-Fluoropyrimidine-based Treatment: A Multicentre, Retrospective Review

AIMS

Although cisplatin-fluoropyrimidine-based definitive chemoradiotherapy (dCRT) is a standard of care for oesophageal cancer, toxicity is significant and limits its use in elderly and frail patients. Weekly carboplatin-paclitaxel-based dCRT provides a viable alternative, although prospective data are lacking in the dCRT setting. Here we report the results of a national, multicentre retrospective review of outcome in patients treated with weekly carboplatin-paclitaxel-based dCRT.

MATERIALS AND METHODS

In this multicentre retrospective study of nine radiotherapy centres across the UK we evaluated the outcome of patients who had non-metastatic, histologically confirmed carcinoma of the oesophagus (adenocarcinoma, squamous cell or undifferentiated; World Health Organization performance status 0-2; stage I-III disease) and had been selected to receive weekly carboplatin-paclitaxel-based dCRT as they were considered not suitable for cisplatin-fluoropyrimidine-based dCRT. dCRT consisted of carboplatin AUC 2 and paclitaxel 50 mg/m2 (days 1, 8, 15, 22, 29) and the recommended radiation dose was 50 Gy in 25 daily fractions. We assessed overall survival, progression-free survival (PFS; overall, local and distant), proportion of patients who were failure free at the response assessment (12 weeks after dCRT), treatment compliance and toxicity.

RESULTS

In total, 214 patients from nine UK centres were treated between 15 February 2013 and 19 March 2019: 39.7% of patients were ≥75 years; 18.7% ≥ 80 years. Indications for weekly carboplatin-paclitaxel-based dCRT were comorbidities (47.2%), clinician choice (36.4%) and poor tolerance/progression on cisplatin-fluoropyrimidine induction chemotherapy (15.8%). The median overall survival was 24.28 months (95% confidence interval 20.07-30.09) and the median PFS was 16.33 months (95% confidence interval 14.29-20.96). Following treatment, 69.1% (96/139) had a combined complete response on endoscopy with non-progression (complete response/partial response/stable disease) on imaging. The 1- and 2-year overall survival rates for this patient group were 81.9% (95% confidence interval 75.6-86.8%) and 50.6% (95% confidence interval 40.5-60.0%), respectively. Thirty-three per cent (n = 70) of patients experienced at least one grade 3 + acute toxicity (grade 3/4 haematological: 10%; grade 3/4 non-haematological: 32%) and there were no treatment-related deaths. 86.9% of patients completed at least four cycles of concomitant weekly carboplatin-paclitaxel-based chemotherapy and planned radiotherapy was completed in 97.7% (209/214).

CONCLUSION

Weekly carboplatin-paclitaxel-based CRT seems to be well tolerated in elderly patients and in those with comorbidities, where cisplatin-fluoropyrimidine-based dCRT is contraindicated. Survival outcomes are comparable with cisplatin-fluoropyrimidine-based dCRT.

Method Extension Study to Validate Applicability of AOAC Official Method 996.14 Assurance® Polyclonal Enzyme Immunoassay for Detection of Listeria monocytogenes and Related Listeria spp. from Environmental Surfaces: Collaborative Study

Test portions from 3 environmental surface types, representative of typical surfaces found in a food production facility, were analyzed by the Assurance®Listeria Polyclonal Enzyme Immunoassay (EIA) and the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) culture method for Listeria monocytogenes and related Listeria species. In all cases, naturally contaminated environmental test samples were collected from an actual food production facility by sponge or swab. Test samples from concrete surfaces were collected by both swab and sponge; sponge test samples were collected from rubber surfaces, and swabs were used to sample steel surfaces. Test portions from each surface type were simultaneously analyzed by both methods. A total of 23 collaborators, representing government agencies, as well as private industry in both the United States and Canada, participated in the study. During this study, a total of 550 test portions and controls was analyzed and confirmed, of which 207 were positive and 336 were negative by both methods. Six test portions were positive by culture, but negative by the EIA. Three test portions were negative by culture, but positive by the EIA. Two test portions were negative by EIA and by culture, but confirmed positive when EIA enrichment broths were subcultured to selective agars. The data reported here indicate that the Assurance®Listeria EIA method and the USDA/FSIS culture method are statistically equivalent for detection of L. monocytogenes and related Listeria species from environmental surfaces taken by sponges or swabs.

Method Extension Study to Validate Applicability of AOAC Official Method 997.03 Visual Immunoprecipitate Assay (VIP®) for Listeria monocytogenes and Related Listeria spp. from Environmental Surfaces: Collaborative Study

Test portions from 3 environmental surface types, representative of typical surfaces found in a food production facility, were analyzed by the Visual Immunoprecipitate assay (VIP®) and the U.S. Department of Agriculture/Food Safety and Inspection Service (USDA/FSIS) culture method for Listeria monocytogenes and related Listeria species. In all cases, naturally contaminated environmental test samples were collected from an actual food production facility by sponge or swab. Test samples from concrete surfaces were collected by both swab and sponge; sponge test samples were collected from rubber surfaces, and swabs were used to sample steel surfaces. Test portions from each surface type were simultaneously analyzed by both methods. A total of 27 laboratories, representing government agencies as well as private industry in both the United States and Canada, participated in the study. During this study, a total of 615 test portions and controls was analyzed and confirmed, of which 227 were positive and 378 were negative by both methods. Nine test portions were positive by culture, but negative by the VIP. Five test portions were negative by culture, but positive by the VIP. Four test portions were negative by VIP and by culture, but confirmed positive when VIP enrichment broths were subcultured to selective agars. The data reported here indicate that the VIP method and the USDA/FSIS culture method are statistically equivalent for detection of L. monocytogenes and related Listeria species from environmental surfaces taken by sponges or swabs.

Whole genome metagenomic analysis of the gut microbiome of differently fed infants identifies differences in microbial composition and functional genes, including an absent CRISPR/Cas9 gene in the formula-fed cohort

BACKGROUND

Advancements in sequencing capabilities have enhanced the study of the human microbiome. There are limited studies focused on the gastro-intestinal (gut) microbiome of infants, particularly the impact of diet between breast-fed (BF) versus formula-fed (FF). It is unclear what effect, if any, early feeding has on short-term or long-term composition and function of the gut microbiome.

RESULTS

Using a shotgun metagenomics approach, differences in the gut microbiome between BF (n = 10) and FF (n = 5) infants were detected. A Jaccard distance principle coordinate analysis was able to cluster BF versus FF infants based on the presence or absence of species identified in their gut microbiome. Thirty-two genera were identified as statistically different in the gut microbiome sequenced between BF and FF infants. Furthermore, the computational workflow identified 371 bacterial genes that were statistically different between the BF and FF cohorts in abundance. Only seven genes were lower in abundance (or absent) in the FF cohort compared to the BF cohort, including CRISPR/Cas9; whereas, the remaining candidates, including autotransporter adhesins, were higher in abundance in the FF cohort compared to BF cohort.

CONCLUSIONS

These studies demonstrated that FF infants have, at an early age, a significantly different gut microbiome with potential implications for function of the fecal microbiota. Interactions between the fecal microbiota and host hinted at here have been linked to numerous diseases. Determining whether these non-abundant or more abundant genes have biological consequence related to infant feeding may aid in understanding the adult gut microbiome, and the pathogenesis of obesity.

Abstract PD8-04: Neoadjuvant chemotherapy for breast cancer: Nodal downstaging is highly correlated with pathological complete response

Background: Neoadjuvant chemotherapy (NAC) is employed in patients with larger tumors to attempt to downstage locally advanced cancers to allow breast conservation and to assess in vivo tumor response. The Multi-Institutional Neoadjuvant Therapy MammaPrint Project I (MINT) study asked a secondary question of whether complete nodal downstaging could also be achieved with NAC.

Methods: This analysis included 147 eligible invasive breast cancer patients with high tumor burdens, classified as cT2-4N0-3M0 (T2 greater than 3.5cm if N0). Patients who had a positive core biopsy and/or fine needle aspiration (FNA) on an axillary node prior to starting NAC were included in this analysis. Those who had a surgical sentinel lymph node biopsy were not included. Nodal involvement was established following neoadjuvant treatment by axillary lymph node dissection (ALND).

Results: This population was 54% postmenopausal, average age 53 yrs (range 25 to 80 yrs). Tumor characteristics were 91% invasive ductal carcinoma; 65% T2, 29% T3, 6% T4; 87% LN1, 13% LN2-3; 3% low grade, 38% intermediate grade, 59% high grade; 65% ER-positive, 49% PR-positive, and 28% HER2-positive by immunohistochemistry; 84% High Risk (HR) and 16% Low Risk (LR) by MammaPrint (MP). After NAC, 45% (66/147) of these LN-positive patients were down-staged to ypN0 and also achieved a complete pathological response in the primary tumor. The potential for down-staging was inversely-related to tumor burden, where 47% (60/128) of N1, 35% (6/17) of N2, and 0% (0/2) of N3 patients were down-staged to ypN0. There were 3 patients who were down-staged (2 N2 to N1, and 1 N3 to N2), but not to ypN0. At surgery, 34% (44/128) of patients had no change, and 19% (24/129) progressed in LN staging.

Pre vs Post NAC Nodal StagePre NAC Nodal StageypN0ypN1ypN2ypN3TotalcN16044222128cN2626317cN3  112Total6646296147

Conclusions: We confirmed that upon achieving a complete response of the primary tumor that there was also a pathologic complete response in the LN. About 53% of patients had no change or progression of LN involvement following NAC.

Citation Format: Blumencranz P, Habibi M, Treece T, Blumencranz L, Yoder E, Audeh W, Carter E, McNaughton L, Roussos J, Shivers S, Acs G, Cox C, MINT Investigators Group. Neoadjuvant chemotherapy for breast cancer: Nodal downstaging is highly correlated with pathological complete response [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD8-04.

Anti-C1 domain antibodies that accelerate factor VIII clearance contribute to antibody pathogenicity in a murine hemophilia A model

Essentials Inhibitor formation remains a challenging complication of hemophilia A care. The Bethesda assay is the primary method used for determining bleeding risk and management. Antibodies that block factor VIII binding to von Willebrand factor can increase FVIII clearance. Antibodies that increase clearance contribute to antibody pathogenicity.

SUMMARY

Background The development of neutralizing anti-factor VIII (FVIII) antibodies remains a challenging complication of modern hemophilia A care. In vitro assays are the primary method used for quantifying inhibitor titers, predicting bleeding risk, and determining bleeding management. However, other mechanisms of inhibition are not accounted for in these assays, which may result in discrepancies between the inhibitor titer and clinical bleeding symptoms. Objectives To evaluate FVIII clearance in vivo as a potential mechanism for antibody pathogenicity and to determine whether increased FVIII dosing regimens correct the associated bleeding phenotype. Methods FVIII-/- or FVIII-/- /von Willebrand factor (VWF)-/- mice were infused with anti-FVIII mAbs directed against the FVIII C1, C2 or A2 domains, followed by infusion of FVIII. Blood loss via the tail snip bleeding model, FVIII activity and FVIII antigen levels were subsequently measured. Results Pathogenic anti-C1 mAbs that compete with VWF for FVIII binding increased the clearance of FVIII-mAb complexes in FVIII-/- mice but not in FVIII-/- /VWF-/- mice. Additionally, pathogenic anti-C2 mAbs that inhibit FVIII binding to VWF increased FVIII clearance in FVIII-/- mice. Anti-C1, anti-C2 and anti-A2 mAbs that do not inhibit VWF binding did not accelerate FVIII clearance. Infusion of increased doses of FVIII in the presence of anti-C1 mAbs partially corrected blood loss in FVIII-/- mice. Conclusions A subset of antibodies that inhibit VWF binding to FVIII increase the clearance of FVIII-mAb complexes, which contributes to antibody pathogenicity. This may explain differences in the bleeding phenotype observed despite factor replacement in some patients with hemophilia A and low-titer inhibitors.

Impact of Psychosocial Risk on Outcomes among Families Seeking Treatment for Obesity

OBJECTIVES

To test the hypothesis that children with elevated psychosocial risk would have increased attrition and worse weight outcomes in weight management treatment.

STUDY DESIGN

This was a prospective cohort study of 100 new patients, aged 4-12 years, in a weight management clinic. Parents completed the Psychosocial Assessment Tool. Logistic regression analyses were conducted to calculate the odds of attrition from the clinic and a nonmeaningful change in body mass index (BMI) z-score (ie, <0.1 unit decrease in BMI z-score) over a 6-month period based on psychosocial risk category, adjusting for child demographics and baseline weight category.

RESULTS

The majority of patients were male (59%), black (36%) or white (43%), and had severe obesity (55%), and 59% of families were categorized as having moderate or high psychosocial risk. Over the 6-month period, 53% of families were lost to follow-up, and 67% did not have a clinically meaningful decrease in BMI z-score. Compared with children of families with low psychosocial risk, children of families with moderate or high psychosocial risk were 3.1 times (95% CI, 1.3-7.2 times) more likely to be lost to follow-up and 2.9 times (95% CI, 1.1-7.9 times) more likely to have a non-clinically meaningful change in BMI z-score.

CONCLUSIONS

Children presenting with increased psychosocial risk have higher attrition and poorer weight outcomes, supporting the need for psychosocial screening as a standard component of pediatric weight management treatment.

Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

The Importance of Dialysate Sodium Concentration in Determining Interdialytic Weight Gains in Chronic Hemodialysis Patients: The PanThames Renal Audit

Background and Objectives

There is controversy as to the optimum dialysate sodium to be used for hemodialysis patients, with reports of hypertension and increased interdialytic weight gains with high sodium dialysates and intradialytic hypotension and cramps with low sodium dialysates.

Methods

We analyzed the effect of different dialysate sodium concentrations during a one-week period in an audit of 2187 established patients regularly receiving dialysis three times a week. Patients were given general dietary advice to restrict dietary sodium intake, but no systematic assessment of dietary sodium intake was undertaken.

Results

The prescription of a dialysate sodium concentration of 140 mmol/L and >140 mmol/L, was associated with greater interdialytic weight gains, 3.5% and 4.1% respectively, compared to 2.8% and 2.7% for those using dialysate sodium concentrations of 137 and 136 mmol/L, respectively (p<0.05). The mean pulse pressure was greater patients dialyzing using a sodium of 140 mmol/L, compared to 136 mmol/L, 70 (13) vs 63 (15) mmHg (p<0.011). In addition, 13.5% of patients using the highest sodium dialysate suffered symptomatic intradialytic hypotension requiring intravenous fluid resuscitation, compared to 2.7% who used the lowest sodium concentrate (p<0.05).

Conclusions

This analysis would support the use of lower dialysate sodium concentrations to aid in reducing interdialytic weight gains and subsequent intradialytic hypotension.

Fall frequency and associated factors among men and women with or at risk for HIV infection

OBJECTIVES

Falls and fall-related injuries are a major public health concern. HIV-infected adults have been shown to have a high incidence of falls. Identification of major risk factors for falls that are unique to HIV infection or similar to those in the general population will inform development of future interventions for fall prevention.

METHODS

HIV-infected and uninfected men and women participating in the Hearing and Balance Substudy of the Multicenter AIDS Cohort Study and Women's Interagency HIV Study were asked about balance symptoms and falls during the prior 12 months. Falls were categorized as 0, 1, or ≥ 2; proportional odds logistic regression models were used to investigate relationships between falls and demographic and clinical variables and multivariable models were created.

RESULTS

Twenty-four per cent of 303 HIV-infected participants reported at least one fall compared with 18% of 233 HIV-uninfected participants (P = 0.27). HIV-infected participants were demographically different from HIV-uninfected participants, and were more likely to report clinical imbalance symptoms (P ≤ 0.035). In univariate analyses, more falls were associated with hepatitis C, female sex, obesity, smoking, and clinical imbalance symptoms, but not age, HIV serostatus or other comorbidities. In multivariable analyses, female sex and imbalance symptoms were independently associated with more falls. Among HIV-infected participants, smoking, a higher number of medications, and imbalance symptoms remained independent fall predictors, while current protease inhibitor use was protective.

CONCLUSIONS

Similar rates of falls among HIV-infected and uninfected participants were largely explained by a high prevalence of imbalance symptoms. Routine assessment of falls and dizziness/imbalance symptoms should be considered, with interventions targeted at reducing symptomatology.

Neither Intraocular Grafts of Retinal Cell Homogenates Nor Live Non-Retinal Neurons Produce Behavioral Recovery in Rats with Light-Damaged Retinas

Previously we have observed that fetal retinal cells grafted to the subretinal space of blind rats produced a functional recovery as determined by testing the visual inhibition of the startle response. Following those studies, we performed experiments to test whether the injection itself, cell by-products, or unrelated neural cells could also produce an effect. Visual function was tested by examining the inhibitory effect of a brief light flash (300 Ix) on the acoustic startle response to an immediately following intense noise burst in light blinded Fischer 344 rats. Animals were tested before and after grafts of fetal retinal cell homogenates, dissociated perinatal cerebellar cells, and sham injections in the subretinal space. Behavioral testing continued every 2 wk for 14 wk after the graft. In the pretests, the light flash inhibited the startle response, maximal at intervals of 40-70 ms with recovery thereafter. In contrast, after exposure for 4 wk to fluorescent light (300 lx) and a rest in a normal 12/12 h light/ dark environment the rats showed reflex facilitation to the light, maximal at an interval of 110 ms, followed by a late period of reflex inhibition. The light flash had no effect on other rats that had been blinded by bilateral enucleation. Light blinded animals receiving either cerebellar grafts or retinal cell homogenates were no different in performance from their sham injected control animals. The present data suggest that neither subretinal injections of neural cells nor nonspecific neurochemical factors are able to elicit a positive behavioral response in visually impaired animals.

Storage of Human Fetal Retina in Optisol Prior to Subretinal Transplantation

We have previously reported that Optisol, a commercially available medium (Chiron Vision, Irvine, CA), is a favorable fluid for the storage of neural retina. We now characterize the cell survival and histologic integrity of the tissue following storage and then transplantation. Neural retinas from human fetal eyes obtained within 1 h of pregnancy termination were stored in Optisol-GS medium (containing TC-199 and MEM medium, 2.5% chondroitin sulfate, 1% dextran, HEPES buffer, gentamicin sulfate, 0.1 mmol/L nonessential amino acids, sodium bicarbonate, 1 mmol/L sodium pyruvate, and additional antioxidants), at 4°C for the following time periods: 0, 1, 2, and 7 days, and then tested for viability. Retinas stored for 2 and 7 days were mechanically dissociated and grafted into the eyes of light-damaged Fischer 344 rats (17 animals, 28 eyes). Non-transplanted eyes received injections of vehicle only (5 animals, 6 eyes). All animals were immunosuppressed daily with cyclosporine (10 mg/kg). All experiments were conducted in strict accordance with institutional, federal, and ARVO guidelines. Cell viability averaged 94.8%, 90.2%, 83.2%, and 76.8% at 0, 1, 2, and 7 days storage, respectively. Light microscopy demonstrated that the fetal retina was preserved without evident changes for up to 48 h. Up to 7 days there was a good to very good preservation of the cells in the outer neuroblastic layer. One month after transplantation subretinal grafts of retinal tissue stored for 2 and 7 days in Optisol showed good integration with host retina and initial photoreceptor differentiation. Optisol is a widely used medium for the preservation of human corneas prior to transplantation. Our results show that this medium is also highly suitable for preserving human fetal retinas prior to transplantation.