Protein Coronas on Functionalized Nanoparticles Enable Quantitative and Precise Large-Scale Deep Plasma Proteomics.

Background: The wide dynamic range of circulating proteins coupled with the diversity of proteoforms present in plasma has historically impeded comprehensive and quantitative characterization of the plasma proteome at scale. Automated nanoparticle (NP) protein corona-based proteomics workflows can efficiently compress the dynamic range of protein abundances into a mass spectrometry (MS)-accessible detection range. This enhances the depth and scalability of quantitative MS-based methods, which can elucidate the molecular mechanisms of biological processes, discover new protein biomarkers, and improve comprehensiveness of MS-based diagnostics. Methods: Investigating multi-species spike-in experiments and a cohort, we investigated fold-change accuracy, linearity, precision, and statistical power for the using the Proteograph™ Product Suite, a deep plasma proteomics workflow, in conjunction with multiple MS instruments. Results: We show that NP-based workflows enable accurate identification (false discovery rate of 1%) of more than 6,000 proteins from plasma (Orbitrap Astral) and, compared to a gold standard neat plasma workflow that is limited to the detection of hundreds of plasma proteins, facilitate quantification of more proteins with accurate fold-changes, high linearity, and precision. Furthermore, we demonstrate high statistical power for the discovery of biomarkers in small- and large-scale cohorts. Conclusions: The automated NP workflow enables high-throughput, deep, and quantitative plasma proteomics investigation with sufficient power to discover new biomarker signatures with a peptide level resolution.

Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement.

Importance: The US and Canada currently have no formal published nationwide guidelines for specialists in poison information or emergency departments for the management of acetaminophen poisoning, resulting in significant variability in management. Objective: To develop consensus guidelines for the management of acetaminophen poisoning in the US and Canada. Evidence Review: Four clinical toxicology societies (America's Poison Centers, American Academy of Clinical Toxicology, American College of Medical Toxicology, and Canadian Association of Poison Control Centers) selected participants (n = 21). Led by a nonvoting chairperson using a modified Delphi method, the panel created a decision framework and determined the appropriate clinical management of a patient with acetaminophen poisoning. Unique to this effort was the collection of guidelines from most poison centers in addition to systematic collection and review of the medical literature. Comments from review by external organizations were incorporated before the guideline was finalized. The project began in March 2021 and ended in March 2023. Findings: The search retrieved 84 guidelines and 278 publications. The panel developed guidelines for emergency department management of single or repeated ingestion of acetaminophen. In addition, the panel addressed extended-release formulation, high-risk ingestion, coingestion of anticholinergics or opioids, age younger than 6 years, pregnancy, weight greater than 100 kg, and intravenous acetaminophen use. Differences from current US practice include defining acute ingestion as an ingestion presentation from 4 to 24 hours after overdose was initiated. A revised form of the Rumack-Matthew nomogram was developed. The term massive ingestion was replaced with the term high-risk ingestion and denoted by a specific nomogram line. Other recommendations include specific criteria for emergency department triage, laboratory evaluation and monitoring parameters, defining the role of gastrointestinal decontamination, detailed management of acetylcysteine treatment, associated adverse effects, and stopping criteria for acetylcysteine treatment, as well as criteria for consultation with a clinical toxicologist. Finally, specific treatment considerations, including acetylcysteine dosing, fomepizole administration, and considerations for extracorporeal elimination and transplant evaluation, were addressed. Conclusions and Relevance: This qualitative study provides a consensus statement on consistent evidence-based recommendations for medical, pharmacy, and nursing education and practice to optimize care of patients with acetaminophen poisoning.

Oral Chemotherapeutic Ingestions Reported to a Poison Control Center Treated in a Health Care Facility.

BACKGROUND: The approach to cancer chemotherapy has changed in recent years, and there are several new oral chemotherapeutics that offer convenience to patients. These medications have toxicity, which may be particularly amplified in an overdose. STUDY DESIGN: This was a retrospective review of all oral chemotherapy overdoses reported to the California Poison Control System between January 2009 and December 2019. Inclusion criteria were all ingestions coded as "antineoplastic, monoclonal antibody, or thalidomide" that were evaluated at a health care facility. We evaluated outcomes per AAPCC criteria (stratified as death, major, moderate, mild, or no effect) as well as symptoms and interventions. RESULTS: There were 314 total cases reported; 169 single-substance ingestions (54%) and 145 cases with coingestant(s) (46%). One hundred eighty cases were female (57%) and 134 male (43%). Age ranges were as follows: ages 1-10 years old (87 cases); ages 11-19 years old (26 cases); 20-59 years old (103 cases); ages 60 and older (98 cases). The majority of cases were unintentional ingestions (199, 63%). The most common medication reported was methotrexate with 140 cases (45%), followed by anastrozole (32 cases) and azathioprine (25 cases). One hundred thirty-eight cases were admitted to the hospital for further care (ICU 63 cases; non-ICU 75 cases). Eighty-four of the methotrexate cases received the antidote leucovorin (60%). Five of the capecitabine ingestions received uridine (36%). Outcomes included 124 cases with no effect, 87 cases with minor effect, 73 case with moderate effect, 26 cases with major effect, and 4 deaths. CONCLUSION: Although methotrexate is the most common oral chemotherapeutic agent involved in overdoses reported to the California Poison Control System, there are many other oral chemotherapeutics from various drug classes, which can lead to toxicity. Although deaths are rare, further studies are needed to determine if particular drugs or drug classes warrant more scrutiny.

Proteome Remodeling of the Eye Lens at 50 Years Identified With Data-Independent Acquisition.

The eye lens is responsible for focusing and transmitting light to the retina. The lens does this in the absence of organelles, yet maintains transparency for at least 5 decades before onset of age-related nuclear cataract (ARNC). It is hypothesized that oxidative stress contributes significantly to ARNC formation. It is in addition hypothesized that transparency is maintained by a microcirculation system that delivers antioxidants to the lens nucleus and exports small molecule waste. Common data-dependent acquisition methods are hindered by dynamic range of lens protein expression and provide limited context to age-related changes in the lens. In this study, we utilized data-independent acquisition mass spectrometry to analyze the urea-insoluble membrane protein fractions of 16 human lenses subdivided into three spatially distinct lens regions to characterize age-related changes, particularly concerning the lens microcirculation system and oxidative stress response. In this pilot cohort, we measured 4788 distinct protein groups, 46,681 peptides, and 7592 deamidated sequences, more than in any previous human lens data-dependent acquisition approach. Principally, we demonstrate that a significant proteome remodeling event occurs at approximately 50 years of age, resulting in metabolic preference for anaerobic glycolysis established with organelle degradation, decreased abundance of protein networks involved in calcium-dependent cell-cell contacts while retaining networks related to oxidative stress response. Furthermore, we identified multiple antioxidant transporter proteins not previously detected in the human lens and describe their spatiotemporal and age-related abundance changes. Finally, we demonstrate that aquaporin-5, among other proteins, is modified with age by post-translational modifications including deamidation and truncation. We suggest that the continued accumulation of each of these age-related outcomes in proteome remodeling contribute to decreased fiber cell permeability and result in ARNC formation.

Lens Aquaporin-5 Inserts Into Bovine Fiber Cell Plasma Membranes Via Unconventional Protein Secretion.

Purpose: To spatially map aquaporin-5 (AQP5) expression in the bovine lens, molecularly characterize cytoplasmic AQP5-containing vesicles in the outer cortex, and elucidate AQP5 membrane trafficking mechanisms. Methods: Immunofluorescence was performed on bovine lens cryosections using AQP5, TOMM20, COX IV, calnexin, LC3B, Sec22ß, LIMP-2, and connexin 50 antibodies and the membrane dye CM-DiI. AQP5 plasma membrane insertion was defined via line expression profile analysis. Transmission electron microscopy (TEM) was performed on bovine lens sections to examine cytoplasmic organelle morphology and subcellular localization in cortical fiber cells. Bovine lenses were treated with 10-nM bafilomycin A1 or 0.1% dimethyl sulfoxide vehicle control for 24 hours in ex vivo culture to determine changes in AQP5 plasma membrane expression. Results: Immunofluorescence analysis revealed cytoplasmic AQP5 expression in lens epithelial cells and differentiating fiber cells. In the lens cortex, complete AQP5 plasma membrane insertion occurs at r/a = 0.951 ± 0.005. AQP5-containing cytoplasmic vesicles are spheroidal in morphology with linear extensions, express TOMM20, and contain LC3B and LIMP-2, but not Sec22ß, as fiber cells mature. TEM analysis revealed complex vesicular assemblies with congruent subcellular localization to AQP5-containing cytoplasmic vesicles. AQP5-containing cytoplasmic vesicles appear to dock with the plasma membrane. Bafilomycin A1 treatment reduced AQP5 plasma membrane expression by 27%. Conclusions: AQP5 localizes to spheroidal, linear cytoplasmic vesicles in the differentiating bovine lens fiber cells. During fiber cell differentiation, these vesicles incorporate LC3B and presumably fuse with LIMP-2-positive lysosomes. Our data suggest that AQP5 to the plasma membrane through lysosome-associated unconventional protein secretion, a novel mechanism of AQP5 trafficking.

Fatal cold medication poisoning in an adolescent.

BACKGROUND: Toxicity from the intentional misuse of over-the-counter (OTC) combination cold products has been widely recognized. Adolescents are most frequently involved and dextromethorphan containing products are the most popular. Desired symptoms include stimulatory effects, euphoria, hallucinations, and dissociation. Potential adverse effects include tachycardia, agitation, hyperthermia, acidosis, and coma. However, mortality is rare [ 1-3]. Co-formulated ingredients such as acetaminophen, pseudoephedrine, and antihistamines may also be present and potentiate dangerous effects. We report a case of an adolescent decedent with markedly elevated postmortem chlorpheniramine (CPA) and dextromethorphan (DXM) blood concentrations and no other identifiable cause of death.

Tissue fixation effects on human retinal lipid analysis by MALDI imaging and LC-MS/MS technologies.

Imaging mass spectrometry (IMS) allows the location and abundance of lipids to be mapped across tissue sections of human retina. For reproducible and accurate information, sample preparation methods need to be optimized. Paraformaldehyde fixation of a delicate multilayer structure like human retina facilitates the preservation of tissue morphology by forming methylene bridge crosslinks between formaldehyde and amine/thiols in biomolecules; however, retina sections analyzed by IMS are typically fresh-frozen. To determine if clinically significant inferences could be reliably based on fixed tissue, we evaluated the effect of fixation on analyte detection, spatial localization, and introduction of artifactual signals. Hence, we assessed the molecular identity of lipids generated by matrix-assisted laser desorption ionization (MALDI-IMS) and liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) for fixed and fresh-frozen retina tissues in positive and negative ion modes. Based on MALDI-IMS analysis, more lipid signals were observed in fixed compared with fresh-frozen retina. More potassium adducts were observed in fresh-frozen tissues than fixed as the fixation process caused displacement of potassium adducts to protonated and sodiated species in ion positive ion mode. LC-MS/MS analysis revealed an overall decrease in lipid signals due to fixation that reduced glycerophospholipids and glycerolipids and conserved most sphingolipids and cholesteryl esters. The high quality and reproducible information from untargeted lipidomics analysis of fixed retina informs on all major lipid classes, similar to fresh-frozen retina, and serves as a steppingstone towards understanding of lipid alterations in retinal diseases.

Data-Independent Acquisition Mass Spectrometry of the Human Lens Enhances Spatiotemporal Measurement of Fiber Cell Aging.

The ocular lens proteome undergoes post-translational and progressive degradation as fiber cells age. The oldest fiber cells and the proteins therein are present at birth and are retained through death. Transparency of the lens is maintained in part by the high abundance Crystallin family proteins (up to 300 mg/mL), which establishes a high dynamic range of protein abundance. As a result, previous data-dependent analysis (DDA) measurements of the lens proteome are less equipped to identify the lowest abundance proteins. To probe more deeply into the lens proteome, we measured the insoluble lens proteome of an 18-year-old human with DDA and data-independent analysis (DIA) methods. By applying more recent library-free DIA search methods, 5,161 protein groups, 50,386 peptides, and 4,960 deamidation sites were detected: significantly outperforming the quantity of identifications in using DDA and pan-human DIA library searches. Finally, by segmenting the lens into multiple fiber cell-age-related regions, we uncovered cell-age-related changes in proteome composition and putative function.

Spatially Resolved Proteomic Analysis of the Lens Extracellular Diffusion Barrier.

Purpose: The presence of a physical barrier to molecular diffusion through lenticular extracellular space has been repeatedly detected. This extracellular diffusion barrier has been proposed to restrict the movement of solutes into the lens and to direct nutrients into the lens core via the sutures at both poles. The purpose of this study is to characterize the molecular components that could contribute to the formation of this barrier. Methods: Three distinct regions in the bovine lens cortex were captured by laser capture microdissection guided by dye penetration. Proteins were digested by Lys C and trypsin. Mass spectrometry-based proteomic analysis followed by gene ontology and protein interaction network analysis was performed. Results: Dye penetration showed that fiber cells first shrink the extracellular spaces of the broad sides followed by closure of the extracellular space between narrow sides at a normalized lens distance (r/a) of 0.9. Accompanying the closure of extracellular space of the broad sides, dramatic proteomic changes were detected, including upregulation of several cell junctional proteins. AQP0 and its interacting partners, Ezrin and Radixin, were among a few proteins that were upregulated, accompanying the closure of extracellular space of the narrow sides, suggesting a particularly important role for AQP0 in controlling the narrowing of the extracellular spaces between fiber cells. The results also provided important information related to biological processes that occur during fiber cell differentiation such as organelle degradation, cytoskeletal remodeling, and glutathione synthesis. Conclusions: The formation of a lens extracellular diffusion barrier is accompanied by significant membrane and cytoskeletal protein remodeling.

Proteomic characterization of the human lens and Cataractogenesis.

INTRODUCTION: The goal of this review is to highlight the triumphs and frontiers in measurement of the lens proteome as it relates to onset of age-related nuclear cataract. As global life expectancy increases, so too does the frequency of age-related nuclear cataracts. Molecular therapeutics do not exist for delay or relief of cataract onset in humans. Since lens fiber cells are incapable of protein synthesis after initial maturation, age-related changes in proteome composition and post-translational modification accumulation can be measured with various techniques. Several of these modifications have been associated with cataract onset. AREAS COVERED: We discuss the impact of long-lived proteins on the lens proteome and lens homeostasis as well as proteomic techniques that may be used to measure proteomes at various levels of proteomic specificity and spatial resolution. EXPERT OPINION: There is clear evidence that several proteome modifications are correlated with cataract formation. Past studies should be enhanced with cutting-edge, spatially resolved mass spectrometry techniques to enhance the specificity and sensitivity of modification detection as it relates to cataract formation.

Risk of toxicity from pediatric topical salicylate ingestions.

INTRODUCTION: Suspected pediatric ingestions of greater than or equal to one teaspoon topical salicylate analgesic are recommended by poison control centers to be managed at healthcare facilities. This cutoff is applied for both liquid and non-liquid (cream, ointment, gel) formulations. METHODS: California poison control cases involving topical salicylate exposures in children less than 6-years-old who were evaluated at a health care facility between 2003 and 2018 were analyzed. RESULTS: Of 599 patient cases, the majority described no or minor symptoms, with gastrointestinal distress being the most common. Signs of salicylate toxicity (metabolic acidosis, tachypnea) occurred in six cases. Seven patients were hospitalized, six of whom were exposed to liquid preparations. DISCUSSION: In line with previous research, liquid salicylate preparations were more frequently associated with the signs of salicylate toxicity and hospitalization. CONCLUSION: There was a low frequency of severe side effects and low hospitalization rates among those referred to a healthcare facility, especially for non-liquid topical salicylate ingestions.

A fluvoxamine-related fatality: Case report with postmortem concentrations.

Fluvoxamine is a selective serotonin reuptake inhibitor that has been considered relatively safe in overdose. At therapeutic and supratherapeutic concentrations, fluvoxamine affects cardiac conduction, prolongs QTc interval, causes hypotension, obtundation, and can increase propensity for seizures. A man in his 60s was found dead at his home with a postmortem fluvoxamine peripheral blood concentration of 4.9 mg/L, and a liver concentration of 440 mg/kg. His cause of death was determined to be acute fluvoxamine toxicity.

An 11-year retrospective review of cyproheptadine use in serotonin syndrome cases reported to the California Poison Control System.

WHAT IS KNOWN: Cyproheptadine is a serotonin and histamine antagonist that has been suggested as a treatment for serotonin syndrome in case reports. OBJECTIVE: We sought to examine the differences between outcomes and treatment recommendations in patients who received and did not receive cyproheptadine for a probable serotonin syndrome. METHODS: A retrospective review of cases reported to the California Poison Control System between 2006 and 2017 involving cyproheptadine administration or consideration for treatment of a probable serotonin syndrome. RESULTS AND DISCUSSION: A total of 1420 cases were identified and 288 cases met the inclusion criteria. Of these, 68 (23.1%) patients received cyproheptadine treatment and were significantly older (mean age 49.7 vs 33.5 years, P < 0.00001), intubated (n = 35, 51% vs n = 62, 28%, P < 0.05) and, although not statistically significant, were more frequently admitted to a critical care unit (n = 56, 82.3% vs n = 154, 70.0%, P = 0.09). There were no significant differences in serious outcomes (moderate or worse effects) or hospitalization rates (OR, 1.09, 95% CI, 0.49-2.64 and OR, 1.99, 95% CI, 0.86-4.58). There were eight fatalities, of which two patients received cyproheptadine. All fatalities were acute polypharmacy ingestions and had manifested severe symptoms (seizures, hypotension or hyperthermia) either prior to the administration or consideration of cyproheptadine therapy. Cyproheptadine was not administered in 138 (48%) cases primarily due to minimal clinical severity and patient improvement (43%), and not recommended in 82 (28%) cases for reasons from waiting for response to other supportive measures (30%), limited evidence of efficacy (28%) and undetermined diagnosis (14.6%). WHAT IS NEW AND CONCLUSION: The benefits of and indications for cyproheptadine are uncertain and questionable for the management of a serotonin syndrome. Future recommendations on its use should be based on diagnostic criteria, severity of symptoms and management in conjunction with other supportive measures.

Exposure Calls to U. S. Poison Centers Involving Electronic Cigarettes and Conventional Cigarettes-September 2010-December 2014.

INTRODUCTION: E-cigarette use is increasing, and the long-term impact on public health is unclear. We described the acute adverse health effects from e-cigarette exposures reported to U.S. poison centers. METHODS: We compared monthly counts and demographic, exposure, and health effects data of calls about e-cigarettes and conventional cigarettes made to poison centers from September 2010 through December 2014. RESULTS: Monthly e-cigarette calls increased from 1 in September 2010, peaked at 401 in April 2014, and declined to 295 in December 2014. Monthly conventional cigarette calls during the same period ranged from 302 to 514. E-cigarette calls were more likely than conventional cigarette calls to report adverse health effects, including vomiting, eye irritation, and nausea. Five e-cigarette calls reported major health effects, such as respiratory failure, and there were two deaths associated with e-cigarette calls. CONCLUSION: E-cigarette calls to U.S. poison centers increased over the study period, and were more likely than conventional cigarettes to report adverse health effects. It is important for health care providers and the public to be aware of potential acute health effects from e-cigarettes. Developing strategies to monitor and prevent poisonings from these novel devices is critical.

Suicide by non-pharmaceutical poisons in San Diego County.

BACKGROUND: In 2010, 6,599 poisoning suicides were reported in the United States (US). While medications remain the primary substances involved in completed poisoning suicides, successful fatal poisonings with non-pharmaceutical substances occur with some regularity. The goal of this study was to identify successful suicides caused by non-pharmaceutical self-poisoning in a large US county over the last 12 years. METHODS: A large US-county medical-examiner's database was queried for all suicides in which exposure to non-pharmaceuticals was listed as the cause of death from 2000 to 2012. Substances were categorized by specific toxin when available and by product type when unavailable. Decedent age, sex, and circumstances surrounding each case were also reviewed. RESULTS: Ages ranged from 18 to 95 (median 48) years. There were 159 (77%) males and 48 females. A total of 11 poisons were utilized. DISCUSSION: Worldwide, intentional CO inhalation is a common method for committing suicide and intentional CO inhalation was the most common method of non-pharmaceutical self-poisoning suicide in our data. Other relatively common poisons including ethylene glycol and cyanide were employed in a relatively constant manner over time as well. Surprisingly, there have been an increasing number of helium-inhalation deaths in recent years. CONCLUSION: Inhaled toxins are the most popular (81%) in non-pharmaceutical suicides, likely due to their rapidity of death. Although much less frequently, individuals successfully employ a broad spectrum of other toxins to commit suicide.

Fatal metformin intoxication with markedly elevated blood and liver concentrations.

The highest postmortem metformin concentrations are recorded utilizing a sensitive and specific analytical procedure. The peripheral blood metformin concentration was 240 mg/L, the liver concentration was 240 mg/kg and the gastric concentration was 1,700 mg. Additionally, an antemortem blood sample collected shortly after admission revealed a metformin concentration of 210 mg/L. These data, revealing a liver to peripheral blood ratio of 1.0, provide additional support that metformin is not subject to postmortem redistribution. Intentional self-poisonings with metformin can result in death, despite multiple medical interventions.