Use of a novel human keratin matrix improves healing rates in diabetic lower extremity wounds.

BACKGROUND: Lower extremity wounds in patients with diabetes are difficult to heal due to an overabundance of pro-inflammatory M1 macrophages, reduced phagocytosis of necrosed cells, and circulatory issues. Keratin biomaterials have been shown to address some of these concerns by encouraging the proliferation of anti-inflammatory M2 macrophages, thereby creating more favorable conditions for wound healing resembling those of patients without diabetes. OBJECTIVE: To investigate the effect of a novel human keratin matrix (HKM) on wound healing. MATERIALS AND METHODS: Ten patients with diabetes with lower extremity wounds at risk for delayed healing underwent wound debridement and application of HKM. Patients received weekly follow-up care and reapplication of HKM until healing occurred; wound size at each visit was used to calculate healing rate. RESULTS: Increased healing rates were noted with HKM compared with standard of care (SOC), including debridement and collagen treatment in all 8 patients who had received SOC prior to HKM treatment. When HKM treatment was alternated with SOC in 2 patients due to other medical conditions, healing rates decreased with SOC and then increased after reintroduction of HKM applications. CONCLUSIONS: These results suggest that HKM may help regulate the pathological processes that contribute to wound chronicity to "kick-start" wound healing. This case series demonstrates that HKM is a promising technology to improve healing rates in nonhealing lower extremity wounds in patients with diabetes.

Transparency and reproducibility in the Adolescent Brain Cognitive Development (ABCD) study.

BACKGROUND: Transparency can build trust in the scientific process, but scientific findings can be undermined by poor and obscure data use and reporting practices. The purpose of this work is to report how data from the Adolescent Brain Cognitive Development (ABCD) Study has been used to date, and to provide practical recommendations on how to improve the transparency and reproducibility of findings. METHODS: Articles published from 2017 to 2023 that used ABCD Study data were reviewed using more than 30 data extraction items to gather information on data use practices. Total frequencies were reported for each extraction item, along with computation of a Level of Completeness (LOC) score that represented overall endorsement of extraction items. Univariate linear regression models were used to examine the correlation between LOC scores and individual extraction items. Post hoc analysis included examination of whether LOC scores were correlated with the logged 2-year journal impact factor. RESULTS: There were 549 full-length articles included in the main analysis. Analytic scripts were shared in 30 % of full-length articles. The number of participants excluded due to missing data was reported in 60 % of articles, and information on missing data for individual variables (e.g., household income) was provided in 38 % of articles. A table describing the analytic sample was included in 83 % of articles. A race and/or ethnicity variable was included in 78 % of reviewed articles, while its inclusion was justified in only 41 % of these articles. LOC scores were highly correlated with extraction items related to examination of missing data. A bottom 10 % of LOC score was significantly correlated with a lower logged journal impact factor when compared to the top 10 % of LOC scores (ß=-0.77, 95 % -1.02, -0.51; p-value < 0.0001). CONCLUSION: These findings highlight opportunities for improvement in future papers using ABCD Study data to readily adapt analytic practices for better transparency and reproducibility efforts. A list of recommendations is provided to facilitate adherence in future research.

Transparency and Reproducibility in the Adolescent Brain Cognitive Development (ABCD) Study.

Background: Transparency can build trust in the scientific process, but scientific findings can be undermined by poor and obscure data use and reporting practices. The purpose of this work is to report how data from the Adolescent Brain Cognitive Development (ABCD) Study has been used to date, and to provide practical recommendations on how to improve the transparency and reproducibility of findings. Methods: Articles published from 2017 to 2023 that used ABCD Study data were reviewed using more than 30 data extraction items to gather information on data use practices. Total frequencies were reported for each extraction item, along with computation of a Level of Completeness (LOC) score that represented overall endorsement of extraction items. Univariate linear regression models were used to examine the correlation between LOC scores and individual extraction items. Post hoc analysis included examination of whether LOC scores were correlated with the logged 2-year journal impact factor. Results: There were 549 full-length articles included in the main analysis. Analytic scripts were shared in 30% of full-length articles. The number of participants excluded due to missing data was reported in 60% of articles, and information on missing data for individual variables (e.g., household income) was provided in 38% of articles. A table describing the analytic sample was included in 83% of articles. A race and/or ethnicity variable was included in 78% of reviewed articles, while its inclusion was justified in only 41% of these articles. LOC scores were highly correlated with extraction items related to examination of missing data. A bottom 10% of LOC score was significantly correlated with a lower logged journal impact factor when compared to the top 10% of LOC scores (ß=-0.77, 95% -1.02, -0.51; p-value < 0.0001). Conclusion: These findings highlight opportunities for improvement in future papers using ABCD Study data to readily adapt analytic practices for better transparency and reproducibility efforts. A list of recommendations is provided to facilitate adherence in future research.

The wingspan suspension approach: A modified semilunar technique for multiple areas of recession.

BACKGROUND: Gingival recession can be considered an undesirable condition that results in the exposure of the root surface. There are many techniques that can be employed to address gingival recession; however, they frequently involve a second surgical site. Other approaches have been introduced in the past to address this concern, and this case study discusses the use of a modified technique to achieve root coverage. METHODS: A patient presented to the periodontics clinic with concerns regarding gingival recession. A modification to the semilunar technique was employed to address the recession, whereas double sling sutures were utilized to maintain the coronal repositioning of the flap. RESULTS: Maxillary central incisors initially presented with 2-3 mm of facial recession and root coverage was achieved by use of a modified surgical semilunar approach. No rebound noted over a 6-month period, newly established gingival margin deemed clinically stable. CONCLUSIONS: This case study provides an alternative to addressing gingival recession in the maxillary anterior region, when <3 mm of recession is noted. Avoidance of a second surgical procedure and/or donor site is of particular benefit, as well as maintenance of the blood supply. KEY POINTS: Why is this case new information? There is insufficient evidence on the use of a modified wingspan incision design Phenotype modification with elimination of a second surgical site is most ideal for the patient. What are the keys to successful management of this case? Comprehensive diagnosis and proper case selection Meticulous flap management and adequate release to allow for repositioning without tension Appropriate use ofsuture and suturing technique. What are the primary limitations to success in this case? Thin periodontal phenotype Poor oral hygiene and plaque accumulation postoperatively Loss to follow-up.

Document analysis of adaptive sport opportunities at Division-1 universities in the United States.

BACKGROUND: Individuals with disabilities are less likely to participate in physical activity, with the greatest decline in participation during college years. Despite known health benefits, there are significant barriers that limit sport and exercise participation for students with disabilities, including adaptive access. To our knowledge, there has been no comprehensive review conducted to examine the number of adaptive sport offerings on a collegiate level. OBJECTIVE: Assess the availability of adaptive sport opportunities for students at National Collegiate Athletic Association (NCAA) Division-1 Universities to better understand university-affiliated adaptive sport opportunity for students. METHODS: Website document analysis was conducted by systematically querying the general homepage, athletics page, and campus recreation websites of each NCAA Division-1 University in the United States (US). Institutional and sport-related characteristics were recorded. RESULTS: Of the 358 NCAA Division-1 Universities, 20.4 % (73/358) marketed adaptive sport opportunities (recreational, club, and/or intercollegiate), with 3.9 % (11/358) acknowledging intercollegiate adaptive sport programs on their websites. Five percent (6/121) of private institutions, and 28.3 % (67/237) of public institutions reported adaptive sport opportunities. The Northeast region had the fewest number of institutions reporting adaptive sport offerings (4/67, 6.0 %). The most commonly offered sport was adaptive recreation (36/358, 10.2 %), followed by wheelchair basketball (26/358, 7.4 %). CONCLUSION: Over three-quarters of Division-1 Universities in the US lack an online description of adaptive sport opportunity, highlighting the need for expanded resourcing and marketing of adaptive sport at the university level. Future studies are necessary to identify appropriate strategies to effectively promote sport, maximize participation and improve social inclusion.

Trauma-Informed Undergraduate Medical Education: A Pathway to Flourishing with Adversity by Enhancing Psychological Safety.

We describe the Life Experiences Curriculum (LEC), which attempts to integrate medical student well-being with trauma-informed medical education. The long-term goal of LEC is to help medical students flourish with adversity and trauma, where flourishing refers to having a sense of purpose that arises from awareness of one's strengths and limitations, shaped by life experiences. The short-term goal of LEC is to develop students' relational capacities, such as acceptance and awareness of self and others, while building and maintaining students' psychological safety. We describe the conceptual rationale for these goals and the curriculum's development, implementation, evaluation, and limitations. The curriculum extends over four years and involves a preclinical seminar and students' individual and group reflection sessions with LEC faculty. The seminar addresses the coexistence of trauma and flourishing across life experiences, as well as how safety in relationships is impaired by traumatic experiences and must be restored for healing and growth. The physician faculty have no role in student evaluation and co-lead all LEC activities. LEC is intended to provide students with new language for understanding the process of trauma and flourishing in both individuals and systems and to build and sustain students' relational capacities. There are ongoing efforts to re-imagine self-care as communal-care in which care and support are given and received in a community of students and faculty. Such a model may help build the relational capacities needed to deliver trauma-informed care and also promote flourishing with adversity in healers and in those seeking to be healed.

Implementation of a Pharmacist-Driven Contraception Service at a Safety-Net Health-System.

Background: Access to safe, effective, and appropriate contraception significantly reduces the rates of unintended pregnancies; however, this preventative care is not always easily accessible. There is a high patient demand for contraception visits that is often delayed or unmet due to lack of access to traditional providers. Pharmacists are highly accessible and can help manage this high demand, yet clinical pharmacists as providers of contraception services remains a gap in published literature. Objective: Develop and implement a pharmacist-led contraception service at a safety-net health-system. Methods: A comprehensive pharmacist-led clinical contraception service was created to improve patient access. To support this project, a collaborative practice agreement (CPA) was developed and enhancements were built into an electronic medical record. The CPA allowed the pharmacist to complete contraception-related interventions such as ordering urine pregnancy tests, prescribing hormonal and emergency contraceptives, and manage adverse effects. The piloting pharmacist was available at the Narcotics Treatment Program (NTP) clinic one half-day each week for scheduled and same-day visits. Results: Within the initial five half-day clinic sessions at NTP, the pharmacist had written seven prescriptions, including three for emergency contraceptives. Of all patients seen for this service at NTP, only one had been using a method of contraception consistently prior to their visit. Conclusion: The interventions that were able to be made by the pharmacist highlighted the need for improved access to contraceptives. Pharmacist-managed services in sexual and reproductive health can help fill this gap. Patients also self-reported ease of access as a benefit to this service.

Synthesis of (2R,4S)-4-Amino-5-hydroxybicyclo[3.1.1]heptane-2-carboxylic Acid via an Asymmetric Intramolecular Mannich Reaction.

Inhibition of human ornithine aminotransferase interferes with glutamine and proline metabolism in hepatocellular carcinoma, depriving tumors of essential nutrients. A proposed mechanism-based inhibitor containing a bicyclo[3.1.1]heptanol warhead is reported herein. The proposed inactivation mechanism involves a novel α-iminol rearrangement. The synthesis of the proposed inhibitor features an asymmetric intramolecular Mannich reaction, utilizing a chiral sulfinamide. This study presents a novel approach toward the synthesis of functionalized bicyclo[3.1.1]heptanes and highlights an underutilized method to access enantiopure exocyclic amines.

A Multicenter, Retrospective Outcome Analysis of Vancomycin Area Under the Curve versus Trough-Based Dosing Strategies in Patients with Burn OR Inhalational Injuries (MONITOR).

Vancomycin is a glycopeptide antibiotic that requires close therapeutic monitoring. Prolonged exposure to elevated concentrations increases risk for serious adverse effects such as nephrotoxicity. However, sub-therapeutic concentrations may lead to bacterial resistance and clinical failure or death. The most recent Infectious Diseases Society of America (IDSA) publication regarding therapeutic monitoring of vancomycin recommends utilizing area under the curve (AUC)-based monitoring to maximize clinical success. Despite the guideline recommendation for AUC-guided dosing, many institutions still use trough-only monitoring in their practices, including those caring for patients with acute burn injuries. Following burn injury, patients are at a higher risk for infections, multi-organ failure, and pharmacokinetic alterations. The primary objective of this multi-center retrospective study is to determine optimal therapeutic monitoring of vancomycin by comparing clinical success between AUC vs. trough-based monitoring in burn patients. MONITOR was a multicenter, retrospective study of patients with thermal or inhalation injury admitted to one of 13 burn centers from 1/1/17 to 8/31/22 who received vancomycin. Demographic and clinical course data, including acute kidney injury (AKI) incidence and clinical success were obtained. Patients were evaluated for clinical success and grouped according to method of monitoring and adjusting doses: AUC vs. trough-based monitoring. Clinical success was a composite definition and lack of meeting any 1 of 5 criteria: 1) persistent infection, 2) relapse, 3) antibiotic failure (clinical worsening), 4) AKI, 5) death. Five-hundred seventeen vancomycin courses were assessed from 485 patients. There was no difference in the rate of clinical success between AUC monitored and the trough-only monitored groups. Incidence of AKI was higher in the trough-only group; however, was not statistically significant after controlling for renal function on admission, past medical history of chronic kidney disease (CKD), and concomitant nephrotoxins.

Repeat controlled human Plasmodium falciparum infections delay bloodstream patency and reduce symptoms.

Resistance to clinical malaria takes years to develop even in hyperendemic regions and sterilizing immunity has rarely been observed. To evaluate the maturation of the host response against controlled repeat exposures to P. falciparum (Pf) NF54 strain-infected mosquitoes, we systematically monitored malaria-naïve participants through an initial exposure to uninfected mosquitoes and 4 subsequent homologous exposures to Pf-infected mosquitoes over 21 months (n = 8 males) (ClinicalTrials.gov# NCT03014258). The primary outcome was to determine whether protective immunity against parasite infection develops following repeat CHMI and the secondary outcomes were to track the clinical signs and symptoms of malaria and anti-Pf antibody development following repeat CHMI. After two exposures, time to blood stage patency increases significantly and the number of reported symptoms decreases indicating the development of clinical tolerance. The time to patency correlates positively with both anti-Pf circumsporozoite protein (CSP) IgG and CD8 + CD69+ effector memory T cell levels consistent with partial pre-erythrocytic immunity. IFNγ levels decrease significantly during the participants' second exposure to high blood stage parasitemia and could contribute to the decrease in symptoms. In contrast, CD4-CD8 + T cells expressing CXCR5 and the inhibitory receptor, PD-1, increase significantly after subsequent Pf exposures, possibly dampening the memory response and interfering with the generation of robust sterilizing immunity.

Selective Reduction of Socioeconomic Disparities in the Experimental Tobacco Marketplace: Effects of Cigarette and E-cigarette Flavor Restrictions.

INTRODUCTION: Cigarette smoking accounts for >30% of the socioeconomic gap in life expectancy. Flavored restrictions claim to promote equity; however, no previous studies have compared the effect of cigarette and e-cigarette flavor restrictions among individuals who smoke with lower and higher socioeconomic status (SES). AIMS AND METHODS: In a between-group within-subject design, individuals with lower (n = 155) and higher (n = 125) SES completed hypothetical purchasing trials in the experimental tobacco marketplace (ETM). Conditions were presented in a 2 × 2 factorial design (cigarette flavors restricted or unrestricted and e-cigarette flavors restricted or unrestricted) with increasing cigarette prices across trials. RESULTS: Results show (1) SES differences in cigarette, e-cigarette, and NRT purchases under unrestricted policies, with lower SES showing higher cigarette demand and lower e-cigarette and NRT substitution than higher SES, (2) cigarette restrictions decreased cigarette and increased NRT purchases among lower SES, but no significant changes among higher SES, (3) decreased SES differences in cigarette demand under cigarette restrictions, but persistence under e-cigarette restrictions or their combination, (4) persistence of SES differences in e-cigarette purchases when all restrictions were enforced, and (5) waning of SES differences in NRT purchasing under all restrictions. CONCLUSIONS: Flavor restrictions differentially affected individuals based on SES. Within-group comparisons demonstrated restrictions significantly impacted lower SES, but not higher SES. Between-group comparisons showed SES differences in cigarette purchasing decreased under cigarette restrictions, but persisted under e-cigarette-restrictions or their combination. Additionally, SES differences in NRT substitution decreased under flavor restrictions. These findings highlight the utility of the ETM to investigate SES disparities. IMPLICATIONS: With increasing trends of socioeconomic differences in smoking prevalence and cessation rates, smoking-related health disparities are expected to continue to widen. Restricting menthol flavor in cigarettes while enhancing the availability and affordability of NRT have the potential to alleviate SES disparities in tobacco use, therefore, positively impacting health equity. However, this effect may depend on flavor availability in other tobacco products.

Cross-situational variability in childhood personality states.

Personality variability is an important individual difference construct that is the focus of major psychological theories and relates to socioemotional functioning. Although cross-situational personality variability has been studied extensively in adult populations, little is known about variability in children's personality. In this study, we aimed to address this gap in knowledge by evaluating whether cross-situational variability is a potentially meaningful individual difference in youth. We used a "thin slice" approach in which research assistants viewed videos of 324 children (Mage = 9.92) completing 15 standardized tasks and rated youth's Big Five personality states. Cross-situational variability in each personality state was estimated by calculating within-person standard deviations across tasks. Results showed that (a) there is substantial variability in children's personality states; (b) children who are variable in one personality domain tend to be variable in other domains; and (c) more variable children are described by their parents as being less competent, less agreeable, less conscientious, and more neurotic. However, associations with parent-rated external criterion were generally small in magnitude, and key psychometric properties of the thin slice personality variability index are not well-established. Our study adds tentative but promising evidence that individual differences in cross-situational personality variability are not only present in childhood but may be consequential. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Effects of spatial variability in vegetation phenology, climate, landcover, biodiversity, topography, and soil property on soil respiration across a coastal ecosystem.

Coastal terrestrial-aquatic interfaces (TAIs) are crucial contributors to global biogeochemical cycles and carbon exchange. The soil carbon dioxide (CO2) efflux in these transition zones is however poorly understood due to the high spatiotemporal dynamics of TAIs, as various sub-ecosystems in this region are compressed and expanded by complex influences of tides, changes in river levels, climate, and land use. We focus on the Chesapeake Bay region to (i) investigate the spatial heterogeneity of the coastal ecosystem and identify spatial zones with similar environmental characteristics based on the spatial data layers, including vegetation phenology, climate, landcover, diversity, topography, soil property, and relative tidal elevation; (ii) understand the primary driving factors affecting soil respiration within sub-ecosystems of the coastal ecosystem. Specifically, we employed hierarchical clustering analysis to identify spatial regions with distinct environmental characteristics, followed by the determination of main driving factors using Random Forest regression and SHapley Additive exPlanations. Maximum and minimum temperature are the main drivers common to all sub-ecosystems, while each region also has additional unique major drivers that differentiate them from one another. Precipitation exerts an influence on vegetated lands, while soil pH value holds importance specifically in forested lands. In croplands characterized by high clay content and low sand content, the significant role is attributed to bulk density. Wetlands demonstrate the importance of both elevation and sand content, with clay content being more relevant in non-inundated wetlands than in inundated wetlands. The topographic wetness index significantly contributes to the mixed vegetation areas, including shrub, grass, pasture, and forest. Additionally, our research reveals that dense vegetation land covers and urban/developed areas exhibit distinct soil property drivers. Overall, our research demonstrates an efficient method of employing various open-source remote sensing and GIS datasets to comprehend the spatial variability and soil respiration mechanisms in coastal TAI. There is no one-size-fits-all approach to modeling carbon fluxes released by soil respiration in coastal TAIs, and our study highlights the importance of further research and monitoring practices to improve our understanding of carbon dynamics and promote the sustainable management of coastal TAIs.

Resolvin E1 improves efferocytosis and rescues severe aplastic anemia in mice.

Severe aplastic anemia (SAA) is a rare, fatal disease characterized by severe cytopenias and loss of hematopoietic stem cells (HSCs). Immune-mediated destruction and inflammation are known drivers of SAA, however, the underlying mechanisms driving persistent inflammation are unknown. Current treatments for SAA rely on immunosuppressive therapies or HSC transplantation, however, these treatments are not always effective. Using an established mouse model of SAA, we observed a significant increase in apoptotic cells within the bone marrow (BM) and impaired efferocytosis in SAA mice, relative to radiation controls. Single-cell transcriptomic analysis revealed heterogeneity among BM monocytes and unique populations emerged during SAA characterized by increased inflammatory signatures and significantly increased expression of Sirpa and Cd47. CD47, a "don't eat me" signal, was increased on both live and apoptotic BM cells, concurrent with markedly increased expression of signal regulatory protein alpha (SIRPα) on monocytes. Functionally, SIRPα blockade improved cell clearance and reduced accumulation of CD47-positive apoptotic cells. Lipidomic analysis revealed a reduction in the precursors of specialized pro-resolving lipid mediators (SPMs) and increased prostaglandins in the BM during SAA, indicative of impaired inflammation resolution. Specifically, 18-HEPE, a precursor of E-series resolvins, was significantly reduced in SAA-induced mice relative to radiation controls. Treatment of SAA mice with Resolvin E1 (RvE1) improved efferocytic function, BM cellularity, platelet output, and survival. Our data suggest that impaired efferocytosis and inflammation resolution contributes to SAA progression and demonstrate that SPMs, such as RvE1, offer new and/or complementary treatments for SAA that do not rely on immune suppression.

CD4 T cells and CD8α+ lymphocytes are necessary for intravenous BCG-induced protection against tuberculosis in macaques.

Tuberculosis (TB) is a major cause of morbidity and mortality worldwide despite widespread intradermal (ID) BCG vaccination in newborns. We previously demonstrated that changing the route and dose of BCG vaccination from 5×105 CFU ID to 5×107 CFU intravenous (IV) resulted in prevention of infection and disease in a rigorous, highly susceptible non-human primate model of TB. Identifying the immune mechanisms of protection for IV BCG will facilitate development of more effective vaccines against TB. Here, we depleted select lymphocyte subsets in IV BCG vaccinated macaques prior to Mtb challenge to determine the cell types necessary for that protection. Depletion of CD4 T cells or all CD8α expressing lymphoycytes (both innate and adaptive) resulted in loss of protection in most macaques, concomitant with increased bacterial burdens (~4-5 log10 thoracic CFU) and dissemination of infection. In contrast, depletion of only adaptive CD8αß+ T cells did not significantly reduce protection against disease. Our results demonstrate that CD4 T cells and innate CD8α+ lymphocytes are critical for IV BCG-induced protection, supporting investigation of how eliciting these cells and their functions can improve future TB vaccines.

Experimental Open Air Burning of Vegetation Enhances Organic Matter Chemical Heterogeneity Compared to Laboratory Burns.

Wildfires produce solid residuals that have unique chemical and physical properties compared to unburned materials, which influence their cycling and fate in the natural environment. Visual burn severity assessment is used to evaluate post-fire alterations to the landscape in field-based studies, yet muffle furnace methods are commonly used in laboratory studies to assess molecular scale alterations along a temperature continuum. Here, we examined solid and leachable organic matter characteristics from chars visually characterized as low burn severity that were created either on an open air burn table or from low-temperature muffle furnace burns. We assessed how the different combustion conditions influence solid and dissolved organic matter chemistries and explored the potential influence of these results on the environmental fate and reactivity. Notably, muffle furnace chars produced less leachable carbon and nitrogen than open air chars across land cover types. Organic matter produced from muffle furnace burns was more homogeneous than open air chars. This work highlights chemical heterogeneities that exist within a single burn severity category, potentially influencing our conceptual understanding of pyrogenic organic matter cycling in the natural environment, including transport and processing in watersheds. Therefore, we suggest that open air burn studies are needed to further advance our understanding of pyrogenic organic matter's environmental reactivity and fate.

Design, Synthesis, and Mechanistic Studies of (R)-3-Amino-5,5-difluorocyclohex-1-ene-1-carboxylic Acid as an Inactivator of Human Ornithine Aminotransferase.

Human ornithine aminotransferase (hOAT), a pyridoxal 5'-phosphate (PLP)-dependent enzyme, has been shown to play an essential role in the metabolic reprogramming and progression of hepatocellular carcinoma (HCC). HCC accounts for approximately 75% of primary liver cancers and is within the top three causes of cancer death worldwide. As a result of treatment limitations, the overall 5-year survival rate for all patients with HCC is under 20%. The prevalence of HCC necessitates continued development of novel and effective treatment methods. In recent years, the therapeutic potential of selective inactivation of hOAT has been demonstrated for the treatment of HCC. Inspired by previous increased selectivity for hOAT by the expansion of the cyclopentene ring scaffold to a cyclohexene, we designed, synthesized, and evaluated a series of novel fluorinated cyclohexene analogues and identified (R)-3-amino-5,5-difluorocyclohex-1-ene-1-carboxylic acid as a time-dependent inhibitor of hOAT. Structural and mechanistic studies have elucidated the mechanism of inactivation of hOAT by 5, resulting in a PLP-inactivator adduct tightly bound to the active site of the enzyme. Intact protein mass spectrometry, 19F NMR spectroscopy, transient state kinetic studies, and X-ray crystallography were used to determine the structure of the final adduct and elucidate the mechanisms of inactivation. Interestingly, despite the highly electrophilic intermediate species conferred by fluorine and structural evidence of solvent accessibility in the hOAT active site, Lys292 and water did not participate in nucleophilic addition during the inactivation mechanism of hOAT by 5. Instead, rapid aromatization to yield the final adduct was favored.