Cost-Benefit Analysis of the CT of the Face in the Evaluation of Traumatic Facial Fractures in an Appalachian Tri-state Geriatric Population.

OBJECTIVE: This study aimed to evaluate the cost vs. benefits of the CT face imaging study in the trauma workup of those over the age of 65. METHODS: We performed a retrospective chart review of 169 trauma patients in our trauma database aged 65 years or older who underwent a CT of the head, a CT of the face, or a CT of the head and CT of the face that resulted in findings of a facial fracture from 2017-2022. Injuries and the treatment they received were documented. If a patient underwent both a CT of the face and a CT of the head, then the author first viewed the CT of the head, documented any injury, and then recorded treatment based on the CT of the head. The CT of the face was then viewed, injuries were recorded, and treatment based on the CT of the face was documented. Statistical analysis was then performed using the paired T-test, McNemar test, and number needed to harm analysis. RESULTS: Of the 169 patients sampled, 159 underwent both CT of the head and the face. There were no patients who underwent a CT of the face exclusively, and only 10 patients underwent a CT of the head exclusively. Of the 159 that had both a CT of the head and the face, the average number of injuries noted on CT of the head + CT of the face vs. CT of the head was 2.42 vs. 1.36, P<.0.0001. The number needed to avoid missing a surgical facial fracture when only a CT of the head was obtained was 14.68. CONCLUSION: The risks of missing a surgical facial fracture outweigh the monetary, radiation, and patient-desired necessity benefits of only performing a CT of the head. A CT of the face should be included in the trauma workup for those over the age of 65 when facial fractures are suspected.

Bridging the Gap: Understanding Appalachian Patient Satisfaction in Cosmetic Rhinoplasty.

Rhinoplasty is a surgical procedure aimed at correcting both functional and aesthetic nasal deformities, addressing issues such as trauma-induced disfigurements and patient dissatisfaction with nasal appearance. Patient satisfaction is a critical outcome measure in rhinoplasty, reflecting the success of the procedure and the quality of care provided. This study investigates factors influencing patient satisfaction among Appalachian patients undergoing rhinoplasty for aesthetic reasons, considering the unique healthcare challenges faced by rural populations. A modified Rhinoplasty Outcome Evaluation questionnaire was utilized to assess patient satisfaction. Descriptive statistics and regression analyses were performed to analyze demographic characteristics, complications, re-operations, and satisfaction scores among rural and urban participants. While no significant differences were found in demographic characteristics, trends in satisfaction scores suggest potential disparities between rural and urban populations. Rural patients exhibited marginally lower satisfaction scores and higher rates of complications and re-operations, highlighting the need for targeted interventions in rural healthcare settings. Addressing geographic barriers, enhancing preoperative education and postoperative support, and fostering interdisciplinary collaboration are essential strategies to improve patient satisfaction and outcomes in rhinoplasty procedures, particularly in rural communities. Further research with larger sample sizes and qualitative methods is warranted to explore the underlying factors contributing to patient satisfaction disparities and to inform evidence-based interventions aimed at narrowing healthcare disparities and advancing health equity in rhinoplasty care.

Impact of Safety Device Features Upon Motor Vehicle Collision Facial Fracture Traumas: A Five-Year Retrospective Study in the Appalachian Tri-State Area.

Motor vehicle collisions (MVCs) represent a significant public health concern, contributing to substantial morbidity and mortality globally. Despite advancements in vehicle safety technology, the impact of safety measures on facial fractures in MVCs remains poorly understood, especially in regions with diverse road conditions like the Appalachian tri-state area. This retrospective study analyzed data from two regional level II trauma centers in Appalachia, focusing on MVC-related facial fractures and safety device usage from January 2017 to December 2021. Descriptive statistics and logistic regression models were employed to assess associations between safety devices and injury outcomes. The study comprised 85 participants, categorized into groups based on safety device usage. Results indicated no significant differences in demographic characteristics, injury severity, surgical intervention rates, or specific facial fractures among groups. These findings challenge some previous research suggesting the protective effects of safety devices on facial fractures in MVCs, underscoring the complex nature of injury prevention in this context. While limitations such as retrospective data collection and sample size constrain generalizability, this study contributes valuable insights for informing injury prevention strategies and trauma care practices in Appalachia and beyond.

Breast Augmentation Patient Satisfaction in an Appalachian Region.

The prevalence of cosmetic plastic surgeries, including breast augmentation, has risen significantly, with breast augmentation being among the most sought-after procedures. However, there's a dearth of research on patient outcomes and satisfaction, particularly in rural areas like the Appalachian region. This retrospective study aimed to fill this gap by examining patient satisfaction and complications following breast augmentation surgery among rural Appalachian patients in the tri-state (West Virginia, Kentucky, and Ohio) area. A total of 63 patients who underwent primary breast augmentation at a regional referral center from June 2014 to December 2022 were included in the study. Patient records were reviewed and data on demographics, complications, re-operations, and satisfaction scores were analyzed. Results revealed no significant differences between rural and urban populations in terms of demographic characteristics, complication rates, re-operation rates, or satisfaction scores. Logistic regression models confirmed that rural/urban status did not significantly influence the likelihood of complications, re-operations, or satisfaction. Despite the study's limitations, including a small sample size and single-center design, the results indicate that rural Appalachian patients receive surgical care comparable to their urban counterparts and experience similar benefits from breast augmentation surgery. Recognizing the distinctive healthcare needs and obstacles faced by rural communities is essential for mitigating healthcare disparities and enhancing overall health outcomes. Future research and healthcare initiatives should prioritize improving access to care, fostering patient-centered approaches, and addressing systemic challenges in healthcare delivery across rural Appalachia.

A Comparative American Board of Surgery In-Training Examination (ABSITE) Performance Analysis Between International vs. Domestic Graduates and Doctor of Medicine (MD) vs. Doctor of Osteopathic Medicine (DO) Medical Degrees.

Introduction The American Board of Surgery (ABS) plays a pivotal role in certifying surgeons in the United States, with the American Board of Surgery In-Training Examination (ABSITE) serving as a critical assessment tool for general surgery residents aspiring for certification. The aim of this study is to compare the performance of international medical graduates (IMGs) to their domestic counterparts and assess the impact of different medical degrees on ABSITE scores. Notably, ABSITE scores often dictate the trajectory of a surgical career, including opportunities for fellowship placements in specialized fields such as plastic surgery. Methods This study focused on general surgery residents enrolled at Marshall University from 2014 to 2022. Data encompassing ABSITE scores, TrueLearn quiz percentages, and TrueLearn mock exam results were collected for analysis. Descriptive statistics summarized sample characteristics, and linear mixed models were employed to address correlations. Statistical analyses were conducted using the Statistical Analysis System (SAS) (version 9.4; SAS Institute Inc., Cary, NC, USA), with significance defined by a two-sided test with p < 0.05. Results Among the 48 participants, comprising 24 non-international medical graduates (nIMGs) and 24 IMGs, IMGs demonstrated superior performance across various metrics. They exhibited higher quiz percentages (67% vs. 61%; p = 0.0029), mock Exam 1 scores (64% vs. 58%; p = 0.0021), mock Exam 2 scores (66% vs. 58%; p = 0.0015), ABSITE scores (560 vs. 505; p = 0.010), and ABSITE percentages (74% vs. 68%; p = 0.0077) compared to nIMGs. Analysis between Doctor of Osteopathic Medicine (DO) and Doctor of Medicine (MD) participants revealed no statistically significant differences in performance metrics, highlighting the comparability of these medical degrees in the context of ABSITE scores and related assessments. Discussion/conclusion This study underscores the superior performance of IMGs over nIMGs in ABSITE examinations, shedding light on the critical role of ABSITE scores in shaping surgical careers. Higher scores correlate with enhanced opportunities for coveted fellowship placements, particularly in specialized fields like plastic surgery. Understanding these dynamics is crucial for resident training and navigating the competitive landscape of surgical sub-specialization. Future research endeavors can delve deeper into the factors influencing ABSITE performance, thereby facilitating the development of targeted interventions to support residents in achieving their career aspirations.

Age-Related Patterns of Traumatic Facial Fractures in the Appalachian Tri-state Area: A Five-Year Retrospective Study.

Introduction Traumatic facial injuries, leading to facial fractures represent a significant subset of traumatic events, with age emerging as a crucial determinant influencing both their etiology and outcomes. Understanding the age-related patterns of traumatic facial fractures is essential for developing targeted prevention and management strategies. In this context, the Appalachian tri-state area stands as an underexplored region concerning this issue, necessitating comprehensive research to elucidate the nuances of age-related traumatic facial fractures within this geographic context. Methods This retrospective study delves into the age-related patterns of traumatic facial fractures within the Appalachian tri-state area, drawing upon patient records from Cabell Huntington Hospital and Saint Mary's Medical Center spanning a five-year period. The study cohort encompasses 623 patients categorized into three age groups: individuals aged <22 years, those aged 22-65 years, and individuals over 65 years. Data analysis involves meticulous examination of mechanisms of injury, injury severity scores (ISSs), hospital length of stay, and the prevalence of surgical interventions across different age cohorts. Results Out of 623 patients, 104 (16.7%) were under 22 years old, 367 (58.9%) were between 22 and 65 years old, and 152 (24.4%) were over 65 years old. The majority were male (70%). Falls were the most common cause of facial fractures in patients over 65 (78%), while assaults were predominant in the 22-65 age group (24%), and motor vehicle collisions (MCVs) in those under 22 (34%). The median ISS and hospital stay durations were similar across age groups. 28% of patients underwent surgery, with significant variation among age groups (p<0.001): 38% for <22 years, 33% for 22-65 years, and 11% for >65 years. Mandibular fractures were more prevalent in younger patients, with rates of 12% for <22 years compared to 5.3% for >65 years. Logistic regression analysis revealed that patients aged 22-65 had 4.10 times higher odds (95% CI=2.38, 7.45, p<0.001) of undergoing surgery, while those under 22 had 5.14 times higher odds (95% CI=2.73, 10.0, p<0.001) compared to those over 65. Significant associations were found for mandibular and bilateral mandibular outcomes in patients aged 22-65 years. Discussion These findings underscore the imperative for tailored prevention strategies and age-specific treatment protocols to optimize patient outcomes. Fall prevention initiatives for the elderly and interventions addressing sports-related injuries for younger individuals are paramount. Moreover, the study highlights the necessity of specialized care protocols for elderly patients to minimize hospital stay durations and manage age-related comorbidities effectively. Moving forward, further research should address limitations, validate findings, and explore the efficacy of specific interventions, thereby paving the way for enhanced preventive measures and management strategies tailored to the diverse age cohorts affected by traumatic facial fractures in the Appalachian region.

Navigating the American Board of Surgery In-Training Examination (ABSITE) Success: Insights From Pre-assessment Practices in Preparing Surgical Residents for Competitive Sub-specialties.

Introduction The American Board of Surgery In-Training Examination (ABSITE) is a critical tool in assessing surgical residents' readiness for board certification and clinical practice. While various factors influencing ABSITE performance have been examined, the impact of innovative educational resources, such as TrueLearn, remains underexplored. TrueLearn's adaptive learning algorithms and comprehensive question banks offer a promising adjunct to traditional study methods. This study investigates the relationship between TrueLearn utilization and ABSITE performance among general surgery residents. Methods This retrospective study, ethically approved by the Marshall University Institutional Review Board (IRB No. 2097669-1), analyzed the performance of general surgery residents at Marshall University from 2014 to 2022. Data were collected on ABSITE scores. Additionally, quiz percentages (Quiz %) and scores from two mock exams (Exam 1 and Exam 2), all provided by the TrueLearn platform, were included in the analysis. Descriptive statistics summarized the sample characteristics. Linear mixed models were employed to examine the associations between TrueLearn engagement and ABSITE performance, accounting for the correlated nature of the data and addressing any missing data at random. Statistical analyses were conducted using the Statistical Analysis System (SAS, version 9.4; SAS Institute Inc., Cary, NC), with significance defined as a p-value < 0.05. Results The study cohort included 58 residents from 2016 to 2022. Linear mixed model analysis revealed significant positive correlations between TrueLearn Quiz %, Exam 1 scores, and Exam 2 scores with ABSITE performance. A 1% increase in Quiz % was associated with a 0.77-point rise in ABSITE scores (95% CI: 0.65, 0.89; p < 0.0001). For Exam 1, each point increase corresponded to a 6.36-point increase in ABSITE scores (95% CI: 5.01, 7.7; p < 0.0001), while Exam 2 scores showed a 3.8-point increase per point (95% CI: 2.74, 4.86; p < 0.0001). Discussion and conclusion Our findings underscore the significant impact of TrueLearn engagement on ABSITE performance, with higher quiz percentages and mock exam scores predictive of better ABSITE outcomes. This suggests that regular use of TrueLearn's educational resources enhances residents' knowledge and exam readiness. These results advocate for the integration of innovative educational tools such as TrueLearn into surgical training programs to optimize study strategies and improve exam performance. However, the study's retrospective design and single-institution focus limit the generalizability of the findings. Future research should explore these relationships in diverse settings and specialties and consider additional factors influencing ABSITE performance. This study highlights the positive association between TrueLearn utilization and ABSITE performance among general surgery residents, emphasizing the importance of innovative educational resources in surgical training. By enhancing engagement with platforms such as TrueLearn, surgical programs can improve residents' readiness for high-stakes examinations, ultimately contributing to the development of proficient surgical practitioners.

Burn Mortality in an Appalachian Referral Center: An Examination of Mortality Prediction Scores in a 13-Year Retrospective Study.

Introduction Burn injuries have profound implications, prompting the use of various mortality scoring systems. This study aimed to evaluate their effectiveness within our Appalachian burn referral center, which serves as the sole burn center in the state of West Virginia. Given this unique status, understanding the efficacy of mortality scoring systems within our center is crucial for resource allocation and optimizing patient outcomes in our region. Methods A retrospective analysis of patients admitted to Cabell Huntington Hospital Burn Intensive Care Unit (BICU) from January 2010 to June 2023 was conducted, assessing Baux (B), revised Baux (rB), Belgian Outcome in Burn Injury (BOBI), and Abbreviated Burn Severity Index (ABSI) scores. Logistic regression and receiver operating characteristic analysis were employed to examine survival status and determine optimal cut points. Results Among 1,104 patients, 57 died (5% mortality rate). Deceased patients had significantly higher B/rB/BOBI scores (mean: 98/98/92) than survivors (45/46/4.19) (p < 0.001), with ABSI showing no significance (p = 0.079). Each one-point increase in B/rB/BOBI scores correlated with a 1.09/1.09/2.34 times higher mortality risk (p < 0.001). The AUC for B score in predicting mortality was 0.926 (95% CI: 0.890, 0.962), with sensitivity and specificity values of 0.789 and 0.92, respectively, and an optimal cutoff point of 79. The AUC for the rB score was 0.927 (95% CI: 0.892, 0.962), with sensitivity and specificity values of 0.789 and 0.926, respectively, and an optimal cutoff point of 80. The AUC for the BOBI score was 0.901 (95% CI: 0.865, 0.937), with sensitivity and specificity values of 0.895 and 0.775, respectively, and an optimal cutoff point of 2. For patients with B scores above 79, their odds of mortality were 42.6 times higher than those with B scores of 79 or lower (95% CI: 22.6, 85.6, p < 0.001). Similarly, for patients with rB scores exceeding 80, their odds of mortality were 42.9 times higher than those with rB scores of 80 or lower (95% CI: 22.9, 84.8, p < 0.001). Finally, for patients with BOBI scores greater than 2, their odds of mortality were 17.8 times higher than those with BOBI scores of 2 or lower (95% CI: 9.88, 33.4, p < 0.001). Conclusion Our study underscores the vital role of mortality scoring systems in guiding clinical decision-making and resource allocation for burn patients, particularly within the Appalachian region served by the Cabell Huntington Hospital BICU. By leveraging tools such as the Baux, revised Baux, and BOBI scores, healthcare providers can identify high-risk patients early in their treatment course, facilitating personalized interventions and improving overall patient outcomes. Moreover, our findings highlight the significance of age and total body surface area burned as key determinants of mortality risk, emphasizing the need for tailored approaches to care for elderly patients and those with extensive burns. Continued research and refinement of mortality scoring systems are essential to further enhance their effectiveness and ensure optimal patient care in the challenging field of burn management.

Evidence-Based Performance Measures for Reconstruction after Skin Cancer Resection: A Multidisciplinary Performance Measure Set.

BACKGROUND: The American Society of Plastic Surgeons commissioned the multidisciplinary Performance Measure Development Work Group on Reconstruction after Skin Cancer Resection to identify and draft quality measures for the care of patients undergoing skin cancer reconstruction. Included stakeholders were the American Academy of Otolaryngology-Head and Neck Surgery, the American Academy of Facial Plastic and Reconstructive Surgery, the American Academy of Dermatology, the American Society of Dermatologic Surgery, the American College of Mohs Surgery, the American Society for Mohs Surgery, and a patient representative. METHODS: Two outcome measures and five process measures were identified. The outcome measures included the following: (1) patient satisfaction with information provided by their surgeon before their facial procedure, and (2) postprocedural urgent care or emergency room use. The process measures focus on antibiotic stewardship, anticoagulation continuation and/or coordination of care, opioid avoidance, and verification of clear margins. RESULTS: All measures in this report were approved by the American Society of Plastic Surgeons Quality and Performance Measures Work Group and Executive Committee, and the stakeholder societies. CONCLUSION: The work group recommends the use of these measures for quality initiatives, Continuing Medical Education, Continuous Certification, Qualified Clinical Data Registry reporting, and national quality reporting programs.

A Rare Case of Extensive Basal Cell Carcinoma With Invasion of the Humerus: Excision and Immediate Reconstruction With Fibula Allograft, Plating, and Latissimus Dorsi Flap.

Basal cell carcinoma (BCC) is the most common skin cancer, and most of the reports have involved the head and neck, but it is rare for it to be highly invasive, with an invasion of long bone being extremely rare. A 73 year old woman presented with a giant BCC on her right arm. Magnetic resonance imaging suggested the involvement of the right humerus. Biopsy confirmed the nodular type of BCC. The patient underwent BCC excision including hemicortical humerus excision with fibula allograft and latissimus dorsi flap with a split-thickness skin graft. Excluding a transient radial nerve palsy, the patient's postoperative course was otherwise uncomplicated. Although BCC invasion into the long bone is extremely rare, the gold standard treatment is, as a rule, en bloc surgical resection with a wide variety of reconstructive techniques. This treatment is only possible through the collaboration of general surgery, orthopedics, and plastic surgery.

Forever young: stem cell and plant regeneration one century after Haberlandt 1921.

Plants are characterized by a post-embryonic mode of organ development, which results in a need for these photoautotrophic organisms to regenerate lost parts in the course of their life cycle. This capacity depends on the presence of "pluripotent stem cells," which are part of the meristems within the plant body. One hundred years ago, the botanist Gottlieb Haberlandt (1854-1945) published experiments showing wounding-induced callus formation, which led ultimately to plant regeneration in tissue culture and thence to the techniques of "plant biotechnology," with practical applications for mankind. Here, we recount Haberlandt's discovery within the context of his long research life and his most influential book Physiologische Pflanzenanatomie. In the second part, we describe and analyze a plant tissue-culture regeneration system using sterile, dark-grown sunflower (Helianthus annuus) seedlings as experimental material. We document that excised hook segments, which contain a "stem cell niche," can regenerate entire miniature H. annuus-plantlets that, raised in a light/dark regime, develop flowers. Finally, we discuss molecular data relevant to plant regeneration with reference to phytohormones and conclude that, one century after Haberlandt, 1921, the exact biochemical/genetic mechanisms responsible for the capability of stem cells to remain "forever young" are, although already complex, really just beginning to become known.

Cryocampsis: a biophysical freeze-bending response of shrubs and trees under snow loads.

We report a biophysical mechanism, termed cryocampsis (Greek cryo-, cold, + campsis, bending), that helps northern shrubs bend downward under a snow load. Subfreezing temperatures substantially increase the downward bending of cantilever-loaded branches of these shrubs, while allowing them to recover their summer elevation after thawing and becoming unloaded. This is counterintuitive, because biological materials (including branches that show cryocampsis) generally become stiffer when frozen, so should flex less, rather than more, under a given bending load. Cryocampsis involves straining of the cell walls of a branch's xylem (wood), and depends upon the branch being hydrated. Among woody species tested, cryocampsis occurs in almost all Arctic, some boreal, only a few temperate and Mediterranean, and no tropical woody species that we have tested. It helps cold-winter climate shrubs reversibly get, and stay, below the snow surface, sheltering them from winter weather and predation hazards. This should be advantageous, because Arctic shrub bud winter mortality significantly increases if their shoots are forcibly kept above the snow surface. Our observations reveal a physically surprising behavior of biological materials at subfreezing temperatures, and a previously unrecognized mechanism of woody plant adaptation to cold-winter climates. We suggest that cryocampsis' mechanism involves the movement of water between cell wall matrix polymers and cell lumens during freezing, analogous to that of frost-heave in soils or rocks.

Optimization of TAM16, a Benzofuran That Inhibits the Thioesterase Activity of Pks13; Evaluation toward a Preclinical Candidate for a Novel Antituberculosis Clinical Target.

With increasing drug resistance in tuberculosis (TB) patient populations, there is an urgent need for new drugs. Ideally, new agents should work through novel targets so that they are unencumbered by preexisting clinical resistance to current treatments. Benzofuran 1 was identified as a potential lead for TB inhibiting a novel target, the thioesterase domain of Pks13. Although, having promising activity against Mycobacterium tuberculosis, its main liability was inhibition of the hERG cardiac ion channel. This article describes the optimization of the series toward a preclinical candidate. Despite improvements in the hERG liability in vitro, when new compounds were assessed in ex vivo cardiotoxicity models, they still induced cardiac irregularities. Further series development was stopped because of concerns around an insufficient safety window. However, the demonstration of in vivo activity for multiple series members further validates Pks13 as an attractive novel target for antitubercular drugs and supports development of alternative chemotypes.

Targeting Mycobacterium tuberculosis CoaBC through Chemical Inhibition of 4'-Phosphopantothenoyl-l-cysteine Synthetase (CoaB) Activity.

Coenzyme A (CoA) is a ubiquitous cofactor present in all living cells and estimated to be required for up to 9% of intracellular enzymatic reactions. Mycobacterium tuberculosis (Mtb) relies on its own ability to biosynthesize CoA to meet the needs of the myriad enzymatic reactions that depend on this cofactor for activity. As such, the pathway to CoA biosynthesis is recognized as a potential source of novel tuberculosis drug targets. In prior work, we genetically validated CoaBC as a bactericidal drug target in Mtb in vitro and in vivo. Here, we describe the identification of compound 1f, a small molecule inhibitor of the 4'-phosphopantothenoyl-l-cysteine synthetase (PPCS; CoaB) domain of the bifunctional Mtb CoaBC, and show that this compound displays on-target activity in Mtb. Compound 1f was found to inhibit CoaBC uncompetitively with respect to 4'-phosphopantothenate, the substrate for the CoaB-catalyzed reaction. Furthermore, metabolomic profiling of wild-type Mtb H37Rv following exposure to compound 1f produced a signature consistent with perturbations in pantothenate and CoA biosynthesis. As the first report of a direct small molecule inhibitor of Mtb CoaBC displaying target-selective whole-cell activity, this study confirms the druggability of CoaBC and chemically validates this target.

Resistance of Mycobacterium tuberculosis to indole 4-carboxamides occurs through alterations in drug metabolism and tryptophan biosynthesis.

Tryptophan biosynthesis represents an important potential drug target for new anti-TB drugs. We identified a series of indole-4-carboxamides with potent antitubercular activity. In vitro, Mycobacterium tuberculosis (Mtb) acquired resistance to these compounds through three discrete mechanisms: (1) a decrease in drug metabolism via loss-of-function mutations in the amidase that hydrolyses these carboxamides, (2) an increased biosynthetic rate of tryptophan precursors via loss of allosteric feedback inhibition of anthranilate synthase (TrpE), and (3) mutation of tryptophan synthase (TrpAB) that decreased incorporation of 4-aminoindole into 4-aminotryptophan. Thus, these indole-4-carboxamides act as prodrugs of a tryptophan antimetabolite, 4-aminoindole.

Spirocycle MmpL3 Inhibitors with Improved hERG and Cytotoxicity Profiles as Inhibitors of Mycobacterium tuberculosis Growth.

With the emergence of multi-drug-resistant strains of Mycobacterium tuberculosis, there is a pressing need for new oral drugs with novel mechanisms of action. A number of scaffolds with potent anti-tubercular in vitro activity have been identified from phenotypic screening that appear to target MmpL3. However, the scaffolds are typically lipophilic, which facilitates partitioning into hydrophobic membranes, and several contain basic amine groups. Highly lipophilic basic amines are typically cytotoxic against mammalian cell lines and have associated off-target risks, such as inhibition of human ether-à-go-go related gene (hERG) and IKr potassium current modulation. The spirocycle compound 3 was reported to target MmpL3 and displayed promising efficacy in a murine model of acute tuberculosis (TB) infection. However, this highly lipophilic monobasic amine was cytotoxic and inhibited the hERG ion channel. Herein, the related spirocycles (1-2) are described, which were identified following phenotypic screening of the Eli Lilly corporate library against M. tuberculosis. The novel N-alkylated pyrazole portion offered improved physicochemical properties, and optimization led to identification of a zwitterion series, exemplified by lead 29, with decreased HepG2 cytotoxicity as well as limited hERG ion channel inhibition. Strains with mutations in MmpL3 were resistant to 29, and under replicating conditions, 29 demonstrated bactericidal activity against M. tuberculosis. Unfortunately, compound 29 had no efficacy in an acute model of TB infection; this was most likely due to the in vivo exposure remaining above the minimal inhibitory concentration for only a limited time.

Inhibiting Mycobacterium tuberculosis CoaBC by targeting an allosteric site.

Coenzyme A (CoA) is a fundamental co-factor for all life, involved in numerous metabolic pathways and cellular processes, and its biosynthetic pathway has raised substantial interest as a drug target against multiple pathogens including Mycobacterium tuberculosis. The biosynthesis of CoA is performed in five steps, with the second and third steps being catalysed in the vast majority of prokaryotes, including M. tuberculosis, by a single bifunctional protein, CoaBC. Depletion of CoaBC was found to be bactericidal in M. tuberculosis. Here we report the first structure of a full-length CoaBC, from the model organism Mycobacterium smegmatis, describe how it is organised as a dodecamer and regulated by CoA thioesters. A high-throughput biochemical screen focusing on CoaB identified two inhibitors with different chemical scaffolds. Hit expansion led to the discovery of potent and selective inhibitors of M. tuberculosis CoaB, which we show to bind to a cryptic allosteric site within CoaB.

Structure-Activity Relationships of Pyrazolo[1,5-a]pyrimidin-7(4H)-ones as Antitubercular Agents.

Pyrazolo[1,5-a]pyrimidin-7(4H)-one was identified through high-throughput whole-cell screening as a potential antituberculosis lead. The core of this scaffold has been identified several times previously and has been associated with various modes of action against Mycobacterium tuberculosis (Mtb). We explored this scaffold through the synthesis of a focused library of analogues and identified key features of the pharmacophore while achieving substantial improvements in antitubercular activity. Our best hits had low cytotoxicity and showed promising activity against Mtb within macrophages. The mechanism of action of these compounds was not related to cell-wall biosynthesis, isoprene biosynthesis, or iron uptake as has been found for other compounds sharing this core structure. Resistance to these compounds was conferred by mutation of a flavin adenine dinucleotide (FAD)-dependent hydroxylase (Rv1751) that promoted compound catabolism by hydroxylation from molecular oxygen. Our results highlight the risks of chemical clustering without establishing mechanistic similarity of chemically related growth inhibitors.

Antitubercular 2-Pyrazolylpyrimidinones: Structure-Activity Relationship and Mode-of-Action Studies.

Phenotypic screening of a Medicines for Malaria Venture compound library against Mycobacterium tuberculosis (Mtb) identified a cluster of pan-active 2-pyrazolylpyrimidinones. The biology triage of these actives using various tool strains of Mtb suggested a novel mechanism of action. The compounds were bactericidal against replicating Mtb and retained potency against clinical isolates of Mtb. Although selected MmpL3 mutant strains of Mtb showed resistance to these compounds, there was no shift in the minimum inhibitory concentration (MIC) against a mmpL3 hypomorph, suggesting mutations in MmpL3 as a possible resistance mechanism for the compounds but not necessarily as the target. RNA transcriptional profiling and the checkerboard board 2D-MIC assay in the presence of varying concentrations of ferrous salt indicated perturbation of the Fe-homeostasis by the compounds. Structure-activity relationship studies identified potent compounds with good physicochemical properties and in vitro microsomal metabolic stability with moderate selectivity over cytotoxicity against mammalian cell lines.

PE/PPE proteins mediate nutrient transport across the outer membrane of Mycobacterium tuberculosis.

Mycobacterium tuberculosis has an unusual outer membrane that lacks canonical porin proteins for the transport of small solutes to the periplasm. We discovered that 3,3-bis-di(methylsulfonyl)propionamide (3bMP1) inhibits the growth of M. tuberculosis, and resistance to this compound is conferred by mutation within a member of the proline-proline-glutamate (PPE) family, PPE51. Deletion of PPE51 rendered M. tuberculosis cells unable to replicate on propionamide, glucose, or glycerol. Growth was restored upon loss of the mycobacterial cell wall component phthiocerol dimycocerosate. Mutants in other proline-glutamate (PE)/PPE clusters, responsive to magnesium and phosphate, also showed a phthiocerol dimycocerosate-dependent growth compromise upon limitation of the corresponding substrate. Phthiocerol dimycocerosate determined the low permeability of the mycobacterial outer membrane, and the PE/PPE proteins apparently act as solute-specific channels.