Noninvasive skin swab analysis detects environmental drug exposure of pharmacy staff.

The skin is complex with multiple layers serving protective, regulatory, and detective functions. The skin hosts chemicals originating from consumption, synthesis, and the environment. Skin chemicals can provide insight into one's daily routine or their level of safety in a work environment. The goal of this study was to investigate the utility of noninvasive skin swabs to detect drugs in a pharmacy setting and to determine whether drugs are transferred to the skin of pharmacy staff. To answer this question, skin swabs were collected from healthy pharmacy staff workers and healthy non-pharmacy individuals and analyzed via untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS). Drugs were annotated through library matching against the GNPS community spectral library. We then used questionnaire data to exclude medications that participants took orally or applied topically and focused on the drugs participants were exposed to in the work setting. Overall, pharmacy staff had a higher number and variety of medications on their skin as compared with healthy individuals who did not work in a pharmacy. In addition, we identified some chemicals such as N,N-Diethyl-metatoluamide on a large number of subjects in both experimental and control groups, indicating environmental exposure to this compound may be ubiquitous and long-lasting.

Open access repository-scale propagated nearest neighbor suspect spectral library for untargeted metabolomics.

Despite the increasing availability of tandem mass spectrometry (MS/MS) community spectral libraries for untargeted metabolomics over the past decade, the majority of acquired MS/MS spectra remain uninterpreted. To further aid in interpreting unannotated spectra, we created a nearest neighbor suspect spectral library, consisting of 87,916 annotated MS/MS spectra derived from hundreds of millions of MS/MS spectra originating from published untargeted metabolomics experiments. Entries in this library, or "suspects," were derived from unannotated spectra that could be linked in a molecular network to an annotated spectrum. Annotations were propagated to unknowns based on structural relationships to reference molecules using MS/MS-based spectrum alignment. We demonstrate the broad relevance of the nearest neighbor suspect spectral library through representative examples of propagation-based annotation of acylcarnitines, bacterial and plant natural products, and drug metabolism. Our results also highlight how the library can help to better understand an Alzheimer's brain phenotype. The nearest neighbor suspect spectral library is openly available for download or for data analysis through the GNPS platform to help investigators hypothesize candidate structures for unknown MS/MS spectra in untargeted metabolomics data.

Urine Excretion, Organ Distribution, and Placental Transfer of 6PPD and 6PPD-Quinone in Mice and Potential Developmental Toxicity through Nuclear Receptor Pathways.

The rubber antioxidant 6PPD has gained significant attention due to its highly toxic transformation product, 6PPD-quinone (6PPDQ). Despite their detection in urines of pregnant women, the placental transfer and developmental toxicity of 6PPD and 6PPDQ are unknown. Here, we treated C57Bl/6 mice with 4 mg/kg 6PPD or 6PPDQ to investigate their urine excretion and placental transfer. Female and male mice exhibited sex difference in excretion profiles of 6PPD and 6PPDQ. Urine concentrations of 6PPDQ were one order of magnitude lower than those of 6PPD, suggesting lower excretion and higher bioaccumulation of 6PPDQ. In pregnant mice treated with 6PPD or 6PPDQ from embryonic day 11.5 to 15.5, 6PPDQ showed ∼1.5-8 times higher concentrations than 6PPD in placenta, embryo body, and embryo brain, suggesting higher placental transfer of 6PPDQ. Using in vitro dual-luciferase reporter assays, we revealed that 6PPDQ activated the human retinoic acid receptor α (RARα) and retinoid X receptor α (RXRα) at concentrations as low as 0.3 µM, which was ∼10-fold higher than the concentrations detected in human urines. 6PPD activated the RXRα at concentrations as low as 1.2 µM. These results demonstrate the exposure risks of 6PPD and 6PPDQ during pregnancy and emphasize the need for further toxicological and epidemiological investigations.

Transfer of antibiotics and their metabolites in human milk: Implications for infant health and microbiota.

Antibiotics are an essential tool for perinatal care. While antibiotics can play a life-saving role for both parents and infants, they also cause collateral damage to the beneficial bacteria that make up the host gut microbiota. This is especially true for infants, whose developing gut microbiota is uniquely sensitive to antibiotic perturbation. Emerging evidence suggests that disruption of these bacterial populations during this crucial developmental window can have long-term effects on infant health and development. Although most current studies have focused on microbial disruptions caused by direct antibiotic administration to infants or prenatal exposure to antibiotics administered to the mother, little is known about whether antibiotics in human milk may pose similar risks to the infant. This review surveys current data on antibiotic transfer during lactation and highlights new methodologies to assess drug transfer in human milk. Finally, we provide recommendations for future work to ensure antibiotic use in lactating parents is safe and effective for both parents and infants.

Trimethylamine N-Oxide Reduces Neurite Density and Plaque Intensity in a Murine Model of Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) is the most common aging-associated neurodegenerative disease; nevertheless, the etiology and progression of the disease is still incompletely understood. We have previously shown that the microbially-derived metabolite trimethylamine N-oxide (TMAO) is elevated in the cerebrospinal fluid (CSF) of individuals with cognitive impairment due to AD and positively correlates with increases in CSF biomarkers for tangle, plaque, and neuronal pathology. OBJECTIVE: We assessed the direct impact of TMAO on AD progression. METHODS: To do so, transgenic 5XFAD mice were supplemented with TMAO for 12 weeks. Neurite density was assessed through quantitative brain microstructure imaging with neurite orientation dispersion and density imaging magnetic resonance imaging (MRI). Label-free, quantitative proteomics was performed on cortex lysates from TMAO-treated and untreated animals. Amyloid-ß plaques, astrocytes, and microglia were assessed by fluorescent immunohistochemistry and synaptic protein expression was quantified via western blot. RESULTS: Oral TMAO administration resulted in significantly reduced neurite density in several regions of the brain. Amyloid-ß plaque mean intensity was reduced, while plaque count and size remained unaltered. Proteomics analysis revealed that TMAO treatment impacted the expression of 30 proteins (1.5-fold cut-off) in 5XFAD mice, including proteins known to influence neuronal health and amyloid-ß precursor protein processing. TMAO treatment did not alter astrocyte and microglial response nor cortical synaptic protein expression. CONCLUSION: These data suggest that elevated plasma TMAO impacts AD pathology via reductions in neurite density.

Correction: McMillen et al. Gut Microbiome Alterations following Postnatal Iron Supplementation Depend on Iron Form and Persist into Adulthood. Nutrients 2022, 14, 412.

Error in Figures and Captions [...].

An untargeted metabolomics analysis of exogenous chemicals in human milk and transfer to the infant.

Human milk is the optimal infant nutrition. However, although human-derived metabolites (such as lipids and oligosaccharides) in human milk are regularly reported, the presence of exogenous chemicals (such as drugs, food, and synthetic compounds) are often not addressed. To understand the types of exogenous compounds that might be present, human milk (n = 996) was analyzed by untargeted metabolomics. This analysis revealed that lifestyle molecules, such as medications and their metabolites, and industrial sources, such as plasticizers, cosmetics, and other personal care products, are found in human milk. We provide further evidence that some of these lifestyle molecules are also detectable in the newborn's stool. Thus, this study gives important insight into the types of exposures infants receiving human milk might ingest due to the lifestyle choices, exposure, or medical status of the lactating parent.

Gut Microbiome Alterations following Postnatal Iron Supplementation Depend on Iron Form and Persist into Adulthood.

The gut microbiota is implicated in the adverse developmental outcomes of postnatal iron supplementation. To generate hypotheses on how changes to the gut microbiota by iron adversely affect development, and to determine whether the form of iron influences microbiota outcomes, we characterized gut microbiome and metabolome changes in Sprague-Dawley rat pups given oral supplements of ferrous sulfate (FS), ferrous bis-glycinate chelate (FC), or vehicle control (CON) on postnatal day (PD) 2−14. Iron supplementation reduced microbiome alpha-diversity (p < 0.0001) and altered short-chain fatty acids (SCFAs) and trimethylamine (TMA) in a form-dependent manner. To investigate the long-term effects of iron provision in early life, an additional cohort was supplemented with FS, FC, or CON until PD 21 and then weaned onto standard chow. At ~8 weeks of age, young adult (YA) rats that received FS exhibited more diverse microbiomes compared to CON (p < 0.05), whereas FC microbiomes were less diverse (p < 0.05). Iron provision resulted in 10,000-fold reduced abundance of Lactobacilli in pre-weanling and YA animals provided iron in early life (p < 0.0001). Our results suggest that in pre-weanling rats, supplemental iron form can generate differential effects on the gut microbiota and microbial metabolism that persist into adulthood.

Oropharyngeal Carcinoma Treated with Surgery Alone: Outcomes and Predictors of Failure.

OBJECTIVE: To analyze the oncologic outcomes and risk factors for recurrence in patients who underwent surgery for oropharyngeal squamous cell carcinoma (OPSCC), and in whom adjuvant therapy was not recommended or was declined. METHODS: Retrospective cohort study of patients with OPSCC who were treated with transoral surgery only at a tertiary care academic medical center from April 2010 to March 2019. RESULTS: Seventy-four patients met inclusion criteria. In 16, adjuvant therapy was recommended but declined. There were 8 recurrences, of which 6 had been given recommendations for adjuvant therapy. Of the 8 recurrences, 2 died, 2 are alive with disease, and 4 were successfully salvaged. Five patients died of unrelated causes. Lymphovascular invasion (LVI, P = .016) had a significant impact on recurrence, while other pathologic features of the primary tumor such as size, location, human papillomavirus (HPV) status, and margin status did not. Margins were classified as "positive" in 4 patients, "close" in 54, and "negative" in 16. There were 3 local recurrences (4.1%), each of whom had declined adjuvant therapy. Lymph node features such as N-stage (P = .0004), number of positive nodes (P = .0005), and presence of extra-nodal extension (ENE, P = .0042) had a statistically significant impact on relapse. Smoking history and surgical approach showed no significant impact on recurrence. CONCLUSION: Patients who undergo surgery for HPV-positive OPSCC with negative margins, no PNI, no LVI, and ≤1 positive lymph node without ENE have low risk for recurrence. These patients can likely be safely treated with surgery alone. Patients with these risk factors who decline adjuvant therapy are at risk for recurrence, and should be monitored.

Short-chain fatty acids activate acetyltransferase p300.

Short-chain fatty acids (SCFAs) acetate, propionate, and butyrate are produced in large quantities by the gut microbiome and contribute to a wide array of physiological processes. While the underlying mechanisms are largely unknown, many effects of SCFAs have been traced to changes in the cell's epigenetic state. Here, we systematically investigate how SCFAs alter the epigenome. Using quantitative proteomics of histone modification states, we identified rapid and sustained increases in histone acetylation after the addition of butyrate or propionate, but not acetate. While decades of prior observations would suggest that hyperacetylation induced by SCFAs are due to inhibition of histone deacetylases (HDACs), we found that propionate and butyrate instead activate the acetyltransferase p300. Propionate and butyrate are rapidly converted to the corresponding acyl-CoAs which are then used by p300 to catalyze auto-acylation of the autoinhibitory loop, activating the enzyme for histone/protein acetylation. This data challenges the long-held belief that SCFAs mainly regulate chromatin by inhibiting HDACs, and instead reveals a previously unknown mechanism of HAT activation that can explain how an influx of low levels of SCFAs alters global chromatin states.