Developing a Paper-Based Antigen Assay to Differentiate between Coronaviruses and SARS-CoV-2 Spike Variants.

COVID-19 first appeared in December of 2019 in Wuhan, China. Since then, it has become a global pandemic. A robust and scalable diagnostics strategy is crucial for containing and monitoring the pandemic. RT-PCR is a known, reliable method for COVID-19 diagnostics, which can differentiate between SARS-CoV-2 and other viruses. However, PCR is location-dependent, time-consuming, and relatively expensive. Thus, there is a need for a more flexible method, which may be produced in an off-the-shelf format and distributed more widely. Paper-based immunoassays can fulfill this function. Here, we present the first steps toward a paper-based test, which can differentiate between different spike proteins of various coronaviruses, SARS-CoV-1, SARS-CoV-2, and CoV-HKU1, with negligible cross-reactivity for HCoV-OC43 and HCoV-229E in a single assay, which takes less than 30 min. Furthermore, our test can distinguish between fractions of the same spike protein. This is done by an altered assay design with four test line locations where each antigen builds a unique, identifiable binding pattern. The effect of several factors, such as running media, immunoprobe concentration, and antigen interference, is considered. We find that running media has a significant effect on the final binding pattern where human saliva provides results while human serum leads to the lowest signal quality.

Designing Paper-Based Immunoassays for Biomedical Applications.

Paper-based sensors and assays have been highly attractive for numerous biological applications, including rapid diagnostics and assays for disease detection, food safety, and clinical care. In particular, the paper immunoassay has helped drive many applications in global health due to its low cost and simplicity of operation. This review is aimed at examining the fundamentals of the technology, as well as different implementations of paper-based assays and discuss novel strategies for improving their sensitivity, performance, or enabling new capabilities. These innovations can be categorized into using unique nanoparticle materials and structures for detection via different techniques, novel biological species for recognizing biomarkers, or innovative device design and/or architecture.

A Mobile App to Increase Informed Decisions About Colorectal Cancer Screening Among African American and Caucasian Women: A Pilot Study.

At this time, there are no interactive mobile apps designed to increase informed decisions about colorectal cancer screening among women. Colorectal cancer is the third leading cause of cancer death among women. The study's purpose was to explore the usability, acceptability, and satisfaction with a mobile app designed to increase colorectal cancer screening informed decisions among 50- to 64-year-old women. Using previous research, an interactive mobile app to increase informed decisions about colorectal cancer screening was developed and pilot tested among African American and Caucasian women (N = 41). In total, 80.6% of women strongly agree/agreed that the mobile app made them think about colorectal cancer screening, 83.8% strongly agree/agreed that the mobile app provided enough information to make a decision about colorectal cancer screening, and 86.1% strongly agree/agreed that the mobile app could help them talk to their provider about colorectal cancer screening. Participants (63.2%) identified family/spouse as who they would talk to about their colorectal cancer screening decision. Participants found the mobile app easy to use and useful in making colorectal cancer screening decisions. Social support is important when making decisions about colorectal cancer screening. Healthcare professionals need new strategies, such as mobile apps, that engage patients, have the potential to increase patient-provider communication, and increase colorectal cancer screening adherence.

A comparison of nanoparticle-antibody conjugation strategies in sandwich immunoassays.

Point-of-care (POC) diagnostics such as lateral flow and dipstick immunoassays use gold nanoparticle (NP)-antibody conjugates for visual readout. We investigated the effects of NP conjugation, surface chemistries, and antibody immobilization methods on dipstick performance. We compared orientational, covalent conjugation, electrostatic adsorption, and a commercial conjugation kit for dipstick assays to detect dengue virus NS1 protein. Assay performance depended significantly on their conjugate properties. We also tested arrangements of multiple test lines within strips. Results show that orientational, covalent conjugation with PEG shield could improve NS1 detection. These approaches can be used to optimize immunochromatographic detection for a range of biomarkers.

Nanomaterial and interface advances in immunoassay biosensors.

Biosensors have been used for a remarkable array of applications, including infectious diseases, environmental monitoring, cancer diagnosis, food safety, and numerous others. In particular, the global COVID-19 pandemic has exposed a need for rapid tests, so the type of biosensor that has gained considerable interest recently are immunoassays, which are used for rapid diagnostics. The performance of paper-based lateral flow and dipstick immunoassays is influenced by the physical properties of the nanoparticles (NPs), NP-antibody conjugates, and paper substrate. Many materials innovations have enhanced diagnostics by increasing sensitivity or enabling unique readouts. However, negative side effects can arise at the interface between the biological sample and biomolecules and the NP or paper substrate, such as non-specific adsorption and protein denaturation. In this Perspective, we discuss the immunoassay components and highlight chemistry and materials innovations that can improve sensitivity. We also explore the range of bio-interface issues that can present challenges for immunoassays.

Correction: SARS-CoV-2 and approaches for a testing and diagnostic strategy.

Correction for 'SARS-CoV-2 and approaches for a testing and diagnostic strategy' by Delyan R. Hristov et al., J. Mater. Chem. B, 2021, 9, 8157-8173, DOI: https://doi.org/10.1039/D1TB00674F.

SARS-CoV-2 and approaches for a testing and diagnostic strategy.

The COVID-19 pandemic has led to an unprecedented global health challenge, creating sudden, massive demands for diagnostic testing, treatment, therapies, and vaccines. In particular, the development of diagnostic assays for SARS-CoV-2 has been pursued as they are needed for quarantine, disease surveillance, and patient treatment. One of the major lessons the pandemic highlighted was the need for fast, cheap, scalable and reliable diagnostic methods, such as paper-based assays. Furthermore, it has previously been suggested that paper-based tests may be more suitable for settings with lower resource availability and may help alleviate some supply chain challenges which arose during the COVID-19 pandemic. Therefore, we explore how such devices may fit in a comprehensive diagnostic strategy and how some of the challenges to the technology, e.g. low sensitivity, may be addressed. We discuss the properties of the SARS-CoV-2 virus itself, the COVID-19 disease pathway, and the immune response. We then describe the different diagnostic strategies that have been pursued, focusing on molecular strategies for viral genetic material, antigen tests, and serological assays, and innovations for improving the diagnostic sensitivity and capabilities. Finally, we discuss pressing issues for the future, and what needs to be addressed for the ongoing pandemic and future outbreaks.

High-Resolution Patterning of Hydrogel Sensing Motifs within Fibrous Substrates for Sensitive and Multiplexed Detection of Biomarkers.

There has been an increasing and urgent demand to develop nucleic acid bioassays which not only offer high analytical performance but which are also amenable with point-of-care testing. Hydrogels present a versatile class of materials with biocompatible antifouling properties and the ability to be engineered for a range of advanced sensing applications. Fibrous substrates like nitrocellulose offer low-cost and durable platforms to run complex bioassays while enabling portability and ease of handling. We demonstrate herein the ability to synergistically combine these two materials into a portable biosensing platform by leveraging projection lithography. We demonstrate the direct polymerization of hydrogel sensing motifs within a range of fibrous substrates with precise control over their shape, size, location, and functionality. Spatial encoding of the hydrogel motifs enables the multiplex detection of multiple biomarkers on the same test. As a proof-of-concept, we apply the platform to the detection of microRNA, an emerging class of circulating biomarkers with promising potential for early diagnosis and monitoring of cancer. The assay offers a large dynamic range (over three orders of magnitude), high sensitivity (limit of detection of 2.5 amol), as well as versatility and ease of handling. Finally, the bioassay is validated using real biological samples, namely, total RNA extracted from the sera of late-stage breast cancer patients, demonstrating its utility and compatibility with clinical biosensing applications.

The Surgical Program in Innovation (SPIN): A Design and Prototyping Curriculum for Surgical Trainees.

PROBLEM: Health professions education does not routinely incorporate training in innovation or creative problem solving. Although some models of innovation education within graduate medical education exist, they often require participants' full-time commitment and removal from clinical training or rely upon participants' existing expertise. There is a need for curricula that teach innovation skills that will enable trainees to identify and solve unmet clinical challenges in everyday practice. To address this gap in surgical graduate education, the authors developed the Surgical Program in Innovation (SPIN). APPROACH: SPIN, a 6-month workshop-based curriculum, was established in 2016 in the Beth Israel Deaconess Medical Center Department of Surgery to teach surgical trainees the basics of the innovation process, focusing on surgeon-driven problem identification, product design, prototype fabrication, and initial steps in the commercialization process. Participating surgical residents and graduate students attend monthly workshops taught by medical, engineering, and medical technology (MedTech) industry faculty. Participants collaborate in teams to develop a novel device, fabricate a protype, and pitch their product to a panel of judges. OUTCOMES: From academic years 2015-2016 to 2017-2018, 49 trainees, including 41 surgical residents, participated in SPIN. Across this period, 13 teams identified an unmet need, ideated a solution, and designed and pitched a novel device. Ten teams fabricated prototypes. The 22 SPIN participants who responded to both pre- and postcourse surveys reported significant increases in confidence in generating problem statements, computer-aided design, fabrication of a prototype, and initial commercialization steps (product pitching and business planning). NEXT STEPS: Incorporating innovation education and design thinking into clinical training will prove essential in preparing future physicians to be lifelong problem finders and solvers. The authors plan to expand SPIN to additional clinical specialties, as well as to assess its impact in fostering future innovation and collaboration among program participants.

The use of a critical care consult team to identify risk for methicillin-resistant Staphylococcus aureus infection and the potential for early intervention: a pilot study.

OBJECTIVE: To test whether a critical care consult team can be used to identify patients who have methicillin-resistant Staphylococcus aureus nasal colonization during a window period at which they are at highest risk for methicillin-resistant S. aureus infection and can most benefit from topical decolonization strategies. DESIGN: Prospective cohort study. SETTING: Two adult tertiary care hospitals. PATIENTS: Patients with at least one risk factor for methicillin-resistant S. aureus nasal colonization who were seen by a critical care consult team for potential intensive care unit admission were enrolled. INTERVENTIONS: Nasal cultures for methicillin-resistant S. aureus were performed on all subjects. All subjects were followed for the development of a methicillin-resistant S. aureus infection for 60 days or until hospital discharge. Demographic and outcome data were recorded on all subjects. MEASUREMENTS AND MAIN RESULTS: Two hundred subjects were enrolled. Overall 29 of 200 (14.5%) were found to have methicillin-resistant S. aureus nasal colonization. Methicillin-resistant S. aureus infections occurred in seven of 29 (24.1%) subjects with methicillin-resistant S. aureus nasal colonization vs. one of 171 (0.6%) subjects without methicillin-resistant S. aureus nasal colonization (p < .001). Methicillin-resistant S. aureus clinical specimens were recovered in 15 of 29 (51.7%) subjects with methicillin-resistant S. aureus nasal colonization vs. two of 171 (1.2%) without methicillin-resistant S. aureus nasal colonization. CONCLUSIONS: A critical care consult team can be used to rapidly recognize patients with methicillin-resistant S. aureus nasal colonization who are at very elevated risk for methicillin-resistant S. aureus infection. The use of such a team to recognize patients who have greatest potential benefit from decolonization techniques might reduce the burden of severe methicillin-resistant S. aureus infections.

Repurposing Old Antibodies for New Diseases by Exploiting Cross-Reactivity and Multicolored Nanoparticles.

We exploit the cross-reactivity of dengue (DENV) and Zika (ZIKV) virus polyclonal antibodies for nonstructural protein 1 (NS1) to construct a selective sensor that can detect yellow fever virus (YFV) NS1 in a manner similar to chemical olfaction. DENV and ZIKV antibodies were screened for their ability to bind to DENV, ZIKV, and YFV NS1 by enzyme linked immunosorbent assay (ELISA) and in pairs in paper immunoassays. A strategic arrangement of antibodies immobilized on paper and conjugated to different colored gold NPs was used to distinguish the three biomarkers. Machine learning of test area RGB values showed that with two spots, readout accuracies of 100% and 87% were obtained for both pure NS1 and DENV/YFV mixtures, respectively. Additional image preprocessing allowed differentiation between all four DENV serotypes with 92% accuracy. The technique was extended to hack a commercial DENV test to detect YFV and ZIKV by augmentation with DENV and ZIKV polyclonal antibodies.

SNAPflex: a paper-and-plastic device for instrument-free RNA and DNA extraction from whole blood.

Nucleic acid amplification tests (NAATs), which amplify and detect pathogen nucleic acids, are vital methods to diagnose diseases, particularly in cases where patients exhibit low levels of infection. For many blood-borne pathogens such as HIV or Plasmodium falciparum, it is necessary to first extract pathogen RNA or DNA from patient blood prior to NAAT analysis. Traditional nucleic acid extraction methods are expensive, resource-intensive and are often difficult to deploy to resource-limited areas where many blood-borne infections are widespread. Here, we describe a portable, paper-and-plastic device, called SNAPflex, for instrument-free nucleic acid extraction from whole blood, which builds upon our previous work for RNA extraction using a pressure-driven extraction system. SNAPflex shows improved HIV RNA extraction from simulated patient samples compared to traditional extraction methods as well as long-term stability of extracted RNA without the need for cold storage. We further demonstrated successful extraction and recovery of P. falciparum DNA from cultured parasites in whole blood. SNAPflex was designed to be easily manufacturable and deployable to resource-limited settings.

[Reproduction, diet and fishery of Octopus (Octopus) hubbsorum (Mollusca: Cephalopoda) in the coast of Oaxaca, Mexico]. / Reproducción, dieta y pesquería del pulpo Octopus (Octopus) hubbsorum (Mollusca: Cephalopoda) en la costa de Oaxaca, México.

The octopus Octopus hubbsorum (Berry 1953) ranges widely and is important for the artisanal fishery in Puerto Angel, Oaxaca, Mexico. Samples were taken approximately at every two weeks from January 2002 to November 2003. All organisms were measured for dorsal mantle length (DLM) and total weight; sex and maturity gonadic stage were registered. For the stomach content analysis, frequency of occurrence and emptying indexes were used. The 352 organisms caught ranged from 4 to 18 cm in DLM; the sex ratio was different from 1 (chi2 = 24.2, p<0.05) throughout the year. The maximum values of the GSI appeared in May (4.1917 for females; 1.2675 in males). LDM for first sexual maturity (LDM50%) was 16 cm (females) and 14 cm (males). Octopus hubbsorum moves from deep waters to the coast, probably in search of better conditions, and lays masses of eggs on rocky substrata. They are fished from March to October, with higher intensity in April and May. Fishing effort was related to the oceanographic characteristics and the atmospheric conditions of the area. From April to September the CPUE monthly mean was 20-10 kg/divers/day. Using the CPUE and environmental condition relationship, the estimated adequate superficial temperature for fishing is 29.5 degrees C.

Distributed Biological Foundries for Global Health.

Historically, many industries such as manufacturing have undergone a trend away from centralized, large-scale production toward a more distributed form. Currently, this same trend is witnessed in biological manufacturing and bioprocessing, with the rise of biological foundries where one can synthesize, grow, isolate, and purify a broad range of biologics. The adoption of distributed practices for biological processing has significant implications for healthcare, diagnostics, and therapies. This essay discusses the many diverse factors that have facilitated this growth, ranging from the establishment of available biological components, or "parts," low-cost programmable hardware, and others. Currently existing examples of distributed biological foundries are also identified, separating the discussion into those that are accessible only by elite users and the more recent emerging foundries that are more accessible to the general population. Taking lessons from other fields, it is argued that this trend toward distributed biological manufacturing is inevitable, so adapting to this trend is important for the progress of creating new therapeutics, sensors, diagnostics, and reagents for biomedical applications.

The oxygen affinity of sickle hemoglobin.

The right-shifted oxyhemoglobin dissociation curve of sickle cell disease (SCD) has been thought to result in abnormally low arterial oxygen saturation (S(o)(2)), even when oxygen partial pressure (P(o)(2)) is normal. However, without polymer formation (minimal under normoxic conditions), HbS oxygen affinity is normal. We hypothesized that in SCD, in vivo S(o)(2) is normal when P(o)(2) is normal. We retrospectively examined 50 blood gas and COoximetry samples from SCD patients and from controls matched for pH, P(o)(2), and carboxyhemoglobin. Control data fell close to the Severinghaus curve, as did non-hypoxemic ( [Formula: see text] ) SCD data. In contrast, hypoxemic (S(o)(2)) < 92.5% SCD data fell well below the standard curve. Thus, although SCD patients' oxygen affinity is low under hypoxic conditions, it is normal at normal arterial S(o)(2). Therefore, a finding of abnormally low saturation demonstrates that P(o)(2) is abnormally low. Given our previous finding that pulse oximetry faithfully reflects saturation in SCD, low pulse oximeter readings in SCD constitute reliable evidence of impaired gas exchange.

Reproduction of the fish Poeciliopsis gracilis (Cyprinodontiformes: Poeciliidae) in Coatetelco, a tropical shallow lake in Mexico.

A reproductive analysis of 1225 specimens of Poeciliopsis gracilis obtained through monthly samples from Coatetelco, a tropical shallow lake in Central Mexico, was made. There was an evident sexual dimorphism, including a difference in body size at the onset of reproduction. Sex ratio deviated significantly from unity. Monthly variations in gonadosomatic (GSI), hepatosomatic (HSI) indexes and ovarian development stages showed that the spawning season was from July to October, coinciding with the rainy season and phytoplankton biomass increase. The largest sizes were 50 mm for females and 43 mm for males.

Age and growth of the tilapia, Oreochromis niloticus (Perciformes: Cichlidae) from a tropical shallow lake in Mexico.

Age and growth of Nile tilapia (Oreochromis niloticus) were determined using 1039 specimens collected in a tropical shallow lake of Mexico, from January to December 1993. Standard length of females ranged from 9.0 to 16.5 cm and males from 8.9 to 14.8 cm. The standard length-weight relationships for all individuals was BW=0.1207 SL2469. The age data, derived from opercular bone readings, were used to estimate the growth parameters of the von Bertalanffy equation: Lx=17.88 cm, K=0.3409, t0=-1.543, and Winfinity=149.21 g. The oldest male and female were 2.5 years old. The sex ratio (female:male) was of 1:1 (chi2=0.02, p>0.05).

Ampli: A Construction Set for Paperfluidic Systems.

The design and fabrication of reconfigurable, modular paperfluidics driven by a prefabricated reusable block library, asynchronous modular paperfluidic linear instrument-free (Ampli) block, are reported. The blocks are inspired by the plug-and-play modularity of electronic breadboards that lower prototyping barriers in circuit design. The resulting biochemical breadboard is a paperfluidic construction set that can be functionalized with chemical, biological, and electrical elements. Ampli blocks can form standard paperfluidic devices without any external instrumentation. Furthermore, their modular nature enhances fluidics in ways that fixed devices cannot. The blocks' ability to start, stop, modify, and reverse reaction flows, reagents, and rates in real time is demonstrated. These enhancements allow users to increase colorimetric signals, fine tune reaction times, and counter check multiplexed diagnostics for false positives or negatives. The modular construction demonstrates that field-ready, distributed fabrication of paper analytical systems can be standardized without requiring the "black box" of craft and technique inherent in paper-based systems. Ampli assembly and point-of-care redesign extends the usability of paper analytical systems and invites user-driven prototyping beyond the lab setting demonstrating "Design for Hack" in diagnostics.

Sore Throat, Fever, Septic Emboli, and Acute Respiratory Distress Syndrome: A Case of Lemierre Syndrome.

Lemierre's syndrome is an acute oropharyngeal infection with a secondary septic thrombophlebitis of the internal jugular vein (IVJ) that was first reported in literature in 1936. It involves the progression of disease from a focal suppurative peritonsillar infection to a local septic thrombophlebitis with hematogenous progression to and distant septic emboli. It is a rare and potentially fatal syndrome requiring prompt diagnosis and management. We present the case progression of an 18-year-old male who presented to our hospital with resolved sore throat, fever, and chest discomfort who experienced a sharp clinical decline. His case, physical exam, laboratory abnormalities, and radiologic studies highlight important facets of this rare but important syndrome.

Calcificación miocárdica de etiología multifactorial / Myocardial calcification with multifactorial etiology

En el presente trabajo se describe un caso de muerte súbita en una mujer de 70 años que fallece 20 días después de ser dada de alta tras ingreso por infección urinaria secundaria a litiasis renal complicada con shock séptico e insuficiencia renal y respiratoria. En el corazón se identificó una cardiopatía isquémica crónica y extensas áreas de miocardio calcificado. Además, se exponen los tipos de calcificaciones del miocardio existentes y sus causas; y se analizan aquellos factores que en el caso presentado han podido causar la calcificación del miocardio(AU)

In the present report, we describe a case of sudden death in a 70-year-old woman who died 20 days after been discharged after admission for urinary infection secondary to renal lithiasis complicated with septic shock and renal and respiratory failure. It has been identified chronic ischemic heart disease and extensive areas of calcified myocardium. Also, we review myocardial calfications subtypes and its causes, and we analyze the specifics of the presented case(AU)