ABSTRACT
The impact of COVID-19 is still felt around the world, and more information is needed regarding infection risk, vaccination responses, and the timing of booster vaccinations. We aimed to evaluate the association of vaccination with closely followed, longitudinal antibody titers and COVID-19 infection events. We conducted a natural history study in a convenience cohort in an ambulatory research unit. We measured anti-nucleocapsid and anti-spike antibody levels every 3 months for 1 year and captured weekly reports of medically confirmed COVID-19 infections. We analyzed the association of antibody titers with infection events as well as the association of the decision to receive vaccination with social, medical, and behavioral characteristics. 629 subjects were followed for 1 year, and 82.8% of them were vaccinated. 90 cases of medically confirmed COVID-19 infection were reported. Notable findings from our study include: an association of vaccination choice with social distancing, a qualitatively different anti-spike response in participants receiving the Ad26.COV2.S vaccine compared to those receiving mRNA vaccines, a muted anti-nucleocapsid response in breakthrough infections compared to unvaccinated infections, and the identification of a low antibody titer threshold associated with the risk of breakthrough infections. We conclude that, in a real-life setting, vaccination and social distancing behavior are positively correlated. The observed effect of vaccination in preventing COVID-19 may include both vaccine-mediated protection and the associated more cautious behavior exhibited by vaccinated individuals. In addition, we identified an antibody threshold associated with breakthrough infections in mRNA vaccinees, and this threshold may be used in medical decision-making regarding the timing of booster vaccinations. Therefore, our data may aid in the refinement of vaccination strategies during the COVID-19 pandemic. IMPORTANCE The COVID-19 pandemic continues to impact societies and health care systems worldwide and is continuously evolving. Immunity via vaccination or prior infection is the first and most important line of defense against COVID-19. We still do not have complete information on how vaccination-induced or infection-induced antibody titers change with time or on how this information can be used to guide decisions regarding booster vaccination. In a longitudinal observational study of a cohort of 629 subjects, 82% of breakthrough infections in vaccinees occurred when their anti-spike antibody titers were below 3,000 AU/mL. Our findings suggest that there may be an antibody threshold associated with breakthrough infections and that this threshold could possibly be used to aid decision-making regarding booster vaccinations. In addition, the use of anti-nucleocapsid antibody tiers may significantly underestimate the prevalence of breakthrough infections in vaccinated individuals.
Subject(s)
COVID-19 , Humans , COVID-19/prevention & control , Pandemics , Ad26COVS1 , Vaccination , Antibodies , Antibodies, ViralABSTRACT
Recent data demonstrate that noradrenergic neurons of the locus coeruleus (LC-NE) are required for fear-induced suppression of feeding, but the role of endogenous LC-NE activity in natural, homeostatic feeding remains unclear. Here, we found that LC-NE activity was suppressed during food consumption, and the magnitude of this neural response was attenuated as mice consumed more pellets throughout the session, suggesting that LC responses to food are modulated by satiety state. Visual-evoked LC-NE activity was also attenuated in sated mice, suggesting that satiety state modulates LC-NE encoding of multiple behavioral states. We also found that food intake could be attenuated by brief or longer durations of LC-NE activation. Last, we found that activation of the LC to the lateral hypothalamus pathway suppresses feeding and enhances avoidance and anxiety-like responding. Our findings suggest that LC-NE neurons modulate feeding by integrating both external cues (e.g., anxiogenic environmental cues) and internal drives (e.g., satiety).
ABSTRACT
Limited data exist on the reproductive hormone dynamics that govern the transition from menarche to the establishment of the mature ovulatory cycles of a fertile young woman. It is also unclear how environmental and lifestyle factors could modulate this transition in contemporary girls. Here, we introduce A Girl's First Period Study, an ambitious longitudinal study aimed at charting the early post-menarchal course of a cohort of healthy girls in the Triangle region of North Carolina.
Subject(s)
Menstrual Cycle , Ovulation , Adolescent , Female , Humans , Longitudinal Studies , Luteinizing Hormone , Menarche , Menstruation DisturbancesABSTRACT
Buprenorphine, an analgesic commonly used in rodent surgery, requires repeated dosing every 4 to 6 h in order to provide adequate analgesia. However, redosing requires repeated handling, which may itself cause stress. Buprenorphine SR-LAB, which reportedly maintains serum levels of buprenorphine greater than 1 ng/mL for 48 to 72 h, is commercially available. However, the viscosity of the product and small dosing volumes make accurate dosing a challenge. Simbadol is a concentrated formulation of buprenorphine hydrochloride labeled for use in cats with recommended dosing frequency of every 24 h. We measured serum concentrations over time after a single injection of this product in C57BL/6NCrl mice and compared it to standard buprenorphine (Buprenex) and Buprenorphine SR-LAB. Male and female mice were injected subcutaneously with one of the 3 buprenorphine formulations at a dose of 1 mg/kg at time 0. Groups of mice (n = 8) were euthanized at 1, 4, 8, 12, 16 h for all groups and 24 h for the Simbadol and the Buprenorphine SR-LAB. Liquid chromatography-mass spectrometry (LC-MS/MS) was used to determine concentrations of buprenorphine in each serum sample. High concentrations were observed in both Simbadol and standard buprenorphine groups one hour after injection (>50 ng/mL). These groups had similar buprenorphine concentration curves, including rates of decline. The standard buprenorphine group had mean concentrations less than 1 ng/mL by 12 h and the Simbadol group by 16 h. In contrast, the Buprenorphine SR-LAB group remained above the 1 ng/mL therapeutic threshold throughout the 24 h. In addition, clinical signs, including increased activity, that lasted for up to an hour after the injection in the Simbadol and standard buprenorphine groups. We conclude that Simbadol does not offer dosing advantages over the standard buprenorphine formulation when given at 1 mg/kg. Buprenorphine SR-LAB maintained a steady concentration of buprenorphine above 1 ng/mL for at least 24 h, and as such is a superior choice for providing long-term analgesia.
Subject(s)
Buprenorphine , Analgesics, Opioid , Animals , Cats , Chromatography, Liquid , Female , Injections, Subcutaneous , Male , Mice , Mice, Inbred C57BL , Tandem Mass SpectrometryABSTRACT
Systemic buprenorphine and topical antiseptics such as chlorhexidine are frequently used in research animals to aid in pain control and to reduce infection, respectively. These therapeutics are controversial, especially when used in wound healing studies, due to conflicting data suggesting that they delay wound healing. Low-level laser therapy (LLLT) has been used to aid in wound healing without exerting the systemic effects of therapies such as buprenorphine. We conducted 2 studies to investigate the effects of these common treatment modalities on the rate of wound healing in mice. The first study used models of punch biopsy and dermal abrasion to assess whether buprenorphine HCl or 0.12% chlorhexidine delayed wound healing. The second study investigated the effects of sustained-released buprenorphine, 0.05% chlorhexidine, and LLLT on excisional wound healing. The rate of wound healing was assessed by obtaining photographs on days 0, 2, 4, 7, and 9 for the punch biopsy model in study 1, days 0, 1, 2, 4, 6, 8, 11, and 13 for the dermal abrasion model in study 1, and days 0, 3, 6, and 10 for the mice in study 2. Image J software was used to analyze the photographed wounds to determine the wound area. When comparing the wound area on the above days to the original wound area, no significant differences in healing were observed for any of the treatment groups at any time period for either study. Given the results of these studies, we believe that systemic buprenorphine, topical chlorhexidine, and LLLT can be used without impairing or delaying wound healing in mice.
Subject(s)
Anti-Infective Agents, Local , Buprenorphine , Laser Therapy , Low-Level Light Therapy , Animals , Chlorhexidine , Mice , Wound HealingABSTRACT
BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) carry significant morbidity and mortality. AECOPD treatment remains limited. High molecular weight hyaluronan (HMW-HA) is a glycosaminoglycan sugar, which is a physiological constituent of the lung extracellular matrix and has notable anti-inflammatory and hydrating properties. RESEARCH QUESTION: We hypothesized that inhaled HMW-HA will improve outcomes in AECOPD. METHODS: We conducted a single center, randomized, placebo-controlled, double-blind study to investigate the effect of inhaled HMW-HA in patients with severe AECOPD necessitating non-invasive positive-pressure ventilation (NIPPV). Primary endpoint was time until liberation from NIPPV. RESULTS: Out of 44 screened patients, 41 were included in the study (21 for placebo and 20 for HMW-HA). Patients treated with HMW-HA had significantly shorter duration of NIPPV. HMW-HA treated patients also had lower measured peak airway pressures on the ventilator and lower systemic inflammation markers after liberation from NIPPV. In vitro testing showed that HMW-HA significantly improved mucociliary transport in air-liquid interface cultures of primary bronchial cells from COPD patients and healthy primary cells exposed to cigarette smoke extract. INTERPRETATION: Inhaled HMW-HA shortens the duration of respiratory failure and need for non-invasive ventilation in patients with AECOPD. Beneficial effects of HMW-HA on mucociliary clearance and inflammation may account for some of the effects (NCT02674880, www.clinicaltrials.gov ).
Subject(s)
Hyaluronic Acid/administration & dosage , Inflammation Mediators/metabolism , Pulmonary Disease, Chronic Obstructive/drug therapy , Pulmonary Disease, Chronic Obstructive/metabolism , Respiratory Insufficiency/drug therapy , Respiratory Insufficiency/metabolism , Adjuvants, Immunologic/administration & dosage , Administration, Inhalation , Aged , Aged, 80 and over , Cells, Cultured , Double-Blind Method , Female , Humans , Inflammation Mediators/antagonists & inhibitors , Length of Stay/trends , Male , Middle Aged , Molecular Weight , Pilot Projects , Tobacco Smoke Pollution/adverse effectsABSTRACT
BACKGROUND: Familial hypercholesterolaemia (FH) is an inherited lipid disorder causing premature heart disease, which is severely underdiagnosed. Improving the identification of people with FH in primary care settings would help to reduce avoidable heart attacks and early deaths. AIM: To evaluate the accuracy of the familial hypercholesterolaemia case ascertainment identifcation tool (FAMCAT) for identifying FH in primary care. DESIGN & SETTING: A retrospective cohort study of 1 030 183 patients was undertaken. Data were extracted from the UK Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) database. Patient were aged >16 years. METHOD: The FAMCAT algorithm was compared with methods of FH detection recommended by national guidelines (Simon Broome diagnostic criteria, Dutch Lipid Clinic Network [DLCN] Score, and cholesterol levels >99th centile). Discrimination and calibration were assessed by area under the receiver operating curve (AUC) and by comparing observed versus predicted cases. RESULTS: A total of 1707 patients had a diagnosis of FH. FAMCAT showed a high level of discrimination (AUC = 0.844, 95% confidence interval [CI] = 0.834 to 0.854), performing significantly better than Simon Broome criteria (AUC = 0.730, 95% CI = 0.719 to 0.741), DLCN Score (AUC = 0.766, 95% CI = 0.755 to 0.778), and screening cholesterols >99 th centile (AUC = 0.579, 95% CI = 0.571 to 0.588). Inclusion of premature myocardial infarction (MI) and fitting cholesterol as a continuous variable improved the accuracy of FAMCAT (AUC = 0.894, 95% CI = 0.885 to 0.903). CONCLUSION: Better performance of the FAMCAT algorithm, compared with other approaches for case finding of FH in primary care, such as Simon Broome criteria, DLCN criteria or very high cholesterol levels, has been confirmed in a large population cohort.
ABSTRACT
BACKGROUND: Influenza contributes significantly to the burden of disease worldwide; the United Kingdom has a policy of vaccination across all ages. Influenza vaccinations are known to be associated with common minor adverse events of interest (AEIs). The European Medicines Agency (EMA) recommends ongoing surveillance of AEIs following influenza vaccination to monitor common and detect infrequent but important AEIs. METHODS: A retrospective cohort study using computerised medical record data from the Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) sentinel network database 2010-2018 (Nâ¯=â¯848,375). We extracted data about vaccine exposure (nâ¯=â¯3,121,334) and consultations for AEIs within seven days of receiving vaccinations specified by the EMA (1,488,870 consultations by 430,029 unique individuals). We used a self-case series design which employs a likelihood estimation method using conditioning of observed adverse events. Such a model assumes non-homogenous Poisson intensity processes for each exposure period and age interval. We compared AEI between QIV and TIV reporting relative incidence (RI) of AEIs. A RIâ¯<â¯1 signified lower AEI rate compared to TIV. RESULTS: QIV was associated with a RI of AEIs of 1.14 (95%CI, 1.10-1.18, pâ¯<â¯0.01), though the number of years exposure was limited. By way of contrast, LAIV had a lower rate 0.60 (95%CI 0.63-0.68, pâ¯<â¯0.001). Cellular manufacture was also associated with a lower rate 0.78 (95%CI 0.61-0.99, pâ¯=â¯0.04). AEIs varied by season: Rash and musculoskeletal conditions are particularly pronounced in the 2014/15 season and respiratory conditions in 2016/17. In an analysis of all seasons, we found an elevated relative incidence of AEIs of 1.78 (95%CI, 1.62-1.95) in pregnant women and 1.76 (95%CI, 1.56 - 1.99) in children under 5â¯years. CONCLUSION: Routine sentinel network data can be used to contrast AEIs between vaccine types and may provide a consistent method of observation of vaccine benefit-risk over time.
Subject(s)
Influenza Vaccines , Vaccination/adverse effects , Child, Preschool , Female , Humans , Influenza Vaccines/adverse effects , Influenza Vaccines/classification , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Pregnancy , Retrospective Studies , Sentinel Surveillance , United KingdomABSTRACT
In compliance with the European Medicine Agency guidance to detect any potential safety concerns associated with influenza vaccination, an enhanced safety surveillance study was conducted in England during the 2017/18 influenza season. The primary objective was to estimate the incidence rates of adverse events occurring within seven days of vaccination with Fluarix Tetra. In nine General Practices, seasonal influenza vaccine was administered to patients according to local guidelines. Events following immunization were collected using customized cards (enhanced component) combined with electronic health records [EHRs] (EHR component) to estimate incidence rates of adverse events experienced post vaccination. The study ran from 01-Sep-2017 to 30-Nov-2017. A total of 23,939 subjects were vaccinated of whom 16,433 received Fluarix Tetra. The cumulative incidence rates of adverse events of interest for Fluarix Tetra were 7.25% [95% CI, 5.95-8.73] for events reported by card alone, and 9.21% [95% CI, 7.37-11.34] when combined with EHR data. The type and frequency of events reported were consistent with the Fluarix Tetra Summary of Product Characteristics. The study supports and confirms the safety profile of Fluarix Tetra. ClinicalTrials.gov number: NCT03278067.
Subject(s)
Influenza Vaccines , Influenza, Human , England/epidemiology , Humans , Influenza Vaccines/adverse effects , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Seasons , Vaccination , Vaccines, InactivatedABSTRACT
BACKGROUND: The European Medicines Agency (EMA) requires vaccine manufacturers to conduct enhanced real-time surveillance of seasonal influenza vaccination. The EMA has specified a list of adverse events of interest to be monitored. The EMA sets out 3 different ways to conduct such surveillance: (1) active surveillance, (2) enhanced passive surveillance, or (3) electronic health record data mining (EHR-DM). English general practice (GP) is a suitable setting to implement enhanced passive surveillance and EHR-DM. OBJECTIVE: This study aimed to test the feasibility of conducting enhanced passive surveillance in GP using the yellow card scheme (adverse events of interest reporting cards) to determine if it has any advantages over EHR-DM alone. METHODS: A total of 9 GPs in England participated, of which 3 tested the feasibility of enhanced passive surveillance and the other 6 EHR-DM alone. The 3 that tested EPS provided patients with yellow (adverse events) cards for patients to report any adverse events. Data were extracted from all 9 GPs' EHRs between weeks 35 and 49 (08/24/2015 to 12/06/2015), the main period of influenza vaccination. We conducted weekly analysis and end-of-study analyses. RESULTS: Our GPs were largely distributed across England with a registered population of 81,040. In the week 49 report, 15,863/81,040 people (19.57% of the registered practice population) were vaccinated. In the EPS practices, staff managed to hand out the cards to 61.25% (4150/6776) of the vaccinees, and of these cards, 1.98% (82/4150) were returned to the GP offices. Adverse events of interests were reported by 113 /7223 people (1.56%) in the enhanced passive surveillance practices, compared with 322/8640 people (3.73%) in the EHR-DM practices. CONCLUSIONS: Overall, we demonstrated that GPs EHR-DM was an appropriate method of enhanced surveillance. However, the use of yellow cards, in enhanced passive surveillance practices, did not enhance the collection of adverse events of interests as demonstrated in this study. Their return rate was poor, data entry from them was not straightforward, and there were issues with data reconciliation. We concluded that customized cards prespecifying the EMA's adverse events of interests, combined with EHR-DM, were needed to maximize data collection. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2016-015469.
ABSTRACT
BACKGROUND: Living in a conurbation, urban, or rural environment is an important determinant of health. For example, conurbation and rural living is associated with increased respiratory and allergic conditions, whereas a farm or rural upbringing has been shown to be a protective factor against this. OBJECTIVE: The objective of the study was to assess differences in general practice presentations of allergic and infectious disease in those exposed to conurbation or urban living compared with rural environments. METHODS: The population was a nationally representative sample of 175 English general practices covering a population of over 1.6 million patients registered with sentinel network general practices. General practice presentation rates per 100,000 population were reported for allergic rhinitis, asthma, and infectious conditions grouped into upper and lower respiratory tract infections, urinary tract infection, and acute gastroenteritis by the UK Office for National Statistics urban-rural category. We used multivariate logistic regression adjusting for age, sex, ethnicity, deprivation, comorbidities, and smoking status, reporting odds ratios (ORs) with 95% CIs. RESULTS: For allergic rhinitis, the OR was 1.13 (95% CI 1.04-1.23; P=.003) for urban and 1.29 (95% CI 1.19-1.41; P<.001) for conurbation compared with rural dwellers. Conurbation living was associated with a lower OR for both asthma (OR 0.70, 95% CI 0.67-0.73; P<.001) and lower respiratory tract infections (OR 0.94, 95% CI 0.90-0.98; P=.005). Compared with rural dwellers, the OR for upper respiratory tract infection was greater in urban (OR 1.06, 95% CI 1.03-1.08; P<.001) but no different in conurbation dwellers (OR 1.00, 95% CI 0.97-1.03; P=.93). Acute gastroenteritis followed the same pattern: the OR was 1.13 (95% CI 1.01-1.25; P=.03) for urban dwellers and 1.04 (95% CI 0.93-1.17; P=.46) for conurbation dwellers. The OR for urinary tract infection was lower for urban dwellers (OR 0.94, 95% CI 0.89-0.99; P=.02) but higher in conurbation dwellers (OR 1.06, 95% CI 1.00-1.13; P=.04). CONCLUSIONS: Those living in conurbations or urban areas were more likely to consult a general practice for allergic rhinitis and upper respiratory tract infection. Both conurbation and rural living were associated with an increased risk of urinary tract infection. Living in rural areas was associated with an increased risk of asthma and lower respiratory tract infections. The data suggest that living environment may affect rates of consultations for certain conditions. Longitudinal analyses of these data would be useful in providing insights into important determinants.
ABSTRACT
BACKGROUND: The Royal College of General Practitioners Research and Surveillance Centre comprises more than 150 general practices, with a combined population of more than 1.5 million, contributing to UK and European public health surveillance and research. OBJECTIVE: The aim of this paper was to report gender differences in the presentation of infectious and respiratory conditions in children and young adults. METHODS: Disease incidence data were used to test the hypothesis that boys up to puberty present more with lower respiratory tract infection (LRTI) and asthma. Incidence rates were reported for infectious conditions in children and young adults by gender. We controlled for ethnicity, deprivation, and consultation rates. We report odds ratios (OR) with 95% CI, P values, and probability of presenting. RESULTS: Boys presented more with LRTI, largely due to acute bronchitis. The OR of males consulting was greater across the youngest 3 age bands (OR 1.59, 95% CI 1.35-1.87; OR 1.13, 95% CI 1.05-1.21; OR 1.20, 95% CI 1.09-1.32). Allergic rhinitis and asthma had a higher OR of presenting in boys aged 5 to 14 years (OR 1.52, 95% CI 1.37-1.68; OR 1.31, 95% CI 1.17-1.48). Upper respiratory tract infection (URTI) and urinary tract infection (UTI) had lower odds of presenting in boys, especially those older than 15 years. The probability of presenting showed different patterns for LRTI, URTI, and atopic conditions. CONCLUSIONS: Boys younger than 15 years have greater odds of presenting with LRTI and atopic conditions, whereas girls may present more with URTI and UTI. These differences may provide insights into disease mechanisms and for health service planning.
ABSTRACT
Providing adequate analgesia while minimizing handling and stress post-surgery can be challenging. Recently, there have been commercial products made available for providing long acting analgesia in rodents. However, we find there are limitations for use in mice due to the viscosity of the product and the small dosing volumes needed. This project evaluated an in-house compounded formulation of buprenorphine easily made in the laboratory using pharmaceutical grade products. The release of buprenorphine was evaluated when compounded with two types of hydrogels (Pluronic(®) F-127 and F-68). Mice given buprenorphine in hydrogel (BP) demonstrated higher serum levels of buprenorphine for a longer period of time compared to mice given standard buprenorphine (Bup). However, the rate of decline in serum levels between the groups was similar; thus, it is more likely that the higher buprenorphine concentration seen in the BP group is due to the higher dose of buprenorphine given, rather than a slower release of product. Feed consumption was decreased in both groups one day after dosing; however, there was no difference in body weights. Increased activity in the open field was observed with both buprenorphine formulations, and lipemia was observed in mice given BP which persisted to at least 96 h. Based on our results, we conclude that this formulation did not sustain the release of buprenorphine or eliminate the increased activity commonly seen in mice given buprenorphine. In addition, the lipemia may confound research parameters, especially in cardiac studies and lipid metabolism studies. Therefore, we cannot recommend this formulation for use.
Subject(s)
Analgesia/veterinary , Analgesics, Opioid/pharmacology , Buprenorphine/pharmacology , Poloxamer , Analgesics, Opioid/blood , Animals , Buprenorphine/blood , Feeding Behavior/drug effects , Hydrogels , Hyperlipidemias/chemically induced , Hyperlipidemias/veterinary , Male , Mice, Inbred C57BL , Motor Activity/drug effectsABSTRACT
INTRODUCTION: There is renewed interest in extracellular vesicles over the past decade or 2 after initially being thought of as simple cellular garbage cans to rid cells of unwanted components. Although there has been intense research into the role of extracellular vesicles in the fields of tumour and stem cell biology, the possible role of extracellular vesicles in nerve regeneration is just in its infancy. BACKGROUND: When a peripheral nerve is damaged, the communication between spinal cord motor neurons and their target muscles is disrupted and the result can be the loss of coordinated muscle movement. Despite state-of-the-art surgical procedures only approximately 10% of adults will recover full function after peripheral nerve repair. To improve upon such results will require a better understanding of the basic mechanisms that influence axon outgrowth and the interplay between the parent motor neuron and the distal end organ of muscle. It has previously been shown that extracellular vesicles are immunologically tolerated, display targeting ligands on their surface, and can be delivered in vivo to selected cell populations. All of these characteristics suggest that extracellular vesicles could play a significant role in nerve regeneration. METHODS: We have carried out studies using 2 very well characterized cell lines, the C2C12 muscle cell line and the motor neuron cell line NSC-34 to ask the question: Do extracellular vesicles from muscle influence cell survival and/or neurite outgrowth of motor neurons? CONCLUSION: Our results show striking effects of extracellular vesicles derived from the muscle cell line on the motor neuron cell line in terms of neurite outgrowth and survival.
ABSTRACT
Cysteine-rich peptides are valued as tags for biarsenical fluorophores and as environmentally important reagents for binding toxic heavy metals. Due to the inherent difficulties created by cysteine, the power of one-bead one-compound (OBOC) libraries has never been applied to the discovery of short cysteine-rich peptides. We have developed the first method for the synthesis, screening, and sequencing of cysteine-rich OBOC peptide libraries. First, we synthesized a heavily biased cysteine-rich OBOC library, incorporating 50% cysteine at each position (Ac-X8-KM-TentaGel). Then, we developed conditions for cysteine alkylation, cyanogen bromide cleavage, and direct MS/MS sequencing of that library at the single bead level. The sequencing efficiency of this library was comparable to a traditional cysteine-free library. To validate screening of cysteine-rich OBOC libraries, we reacted a library with the biarsenical FlAsH and identified beads bearing the known biarsenical-binding motif (CCXXCC). These results enable OBOC libraries to be used in high-throughput discovery of cysteine-rich peptides for protein tagging, environmental remediation of metal contaminants, or cysteine-rich pharmaceuticals.