Toward Machine Learning-Driven Mass Spectrometric Identification of Trichothecenes in the Absence of Standard Reference Materials.

While a significant body of work exists on the detection of commonly known trichothecene toxins, biological, environmental, and other transformational processes can generate many under-characterized and unknown modified trichothecenes. Lacking both analytical reference standards and associated mass spectral databases, identification of these modified compounds reflects both a challenge and a critical gap from forensic and public health perspectives. We report here the application of machine learning (ML) techniques toward identification of discriminative fragment ions from mass spectrometric data that can be exploited to detect evidence of type A and B trichothecenes. The goal of this work is to establish a new method for the identification of unknown, though structurally similar trichothecenes, by leveraging objective ML techniques. Discriminative fragments derived from a series of gradient-boosted machine learners are then used to develop ML-driven precursor ion scan (PIS) methods on a triple quadrupole mass spectrometer (QQQ) for screening of "unknown unknown" trichothecenes. Specifically, we apply the PIS method to a laboratory-synthesized trichothecene, a first step in demonstrating the power of alternative, machine learning-driven mass spectrometric methods.

Interobserver Analysis of Standard Foot and Ankle Radiographic Angles.

Standard foot and ankle radiographs have long been studied and averages formulated in an attempt to provide a common framework for understanding the relationships of the foot and ankle, not only for surgical planning but also to determine normal versus abnormal relationships. The authors describe 8 angles measured on 100 patients by up to 18 observers (4 attending physicians, 12 residents, and 2 students). This study validates the previously documented normal angles using a significantly larger observer group as well as a greater number of analyzed angles. Additionally, this study reveals the tibio-second metatarsal angle on the calcaneal axial view is not a reliable radiographic angle for evaluation of foot and ankle deformity. Intraclass correlation coefficients were also analyzed, which displayed variability in measurements based on level of training, with residents being the most accurate, followed by attending physicians and then students. Foot and ankle radiographs are essential for surgical planning, and understanding normal versus abnormal is key before any surgical planning can be accurately performed.

Use of carbonyldiimidazole as a derivatization agent for the detection of pinacolyl alcohol, a forensic marker for Soman, by EI-GC-MS and LC-HRMS in official OPCW proficiency test matrices.

Pinacolyl alcohol (PA), a key forensic marker for the nerve agent Soman (GD), is a particularly difficult analyte to detect by various analytical methods. In this work, we have explored the reaction between PA and 1,1'-carbonyldiimidazole (CDI) to yield pinacolyl 1H-imidazole-1-carboxylate (PIC), a product that can be conveniently detected by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Regarding its GC-MS profile, this new carbamate derivative of PA possesses favorable chromatographic features such as a sharp peak and a longer retention time (RT = 16.62 min) relative to PA (broad peak and short retention time, RT = 4.1 min). The derivative can also be detected by LC-HRMS, providing an avenue for the analysis of this chemical using this technique where PA is virtually undetectable unless present in large concentrations. From a forensic science standpoint, detection of this low molecular weight alcohol signals the past or latent presence of the nerve agent Soman (GD) in a given matrix (i.e., environmental or biological). The efficiency of the protocol was tested separately in the analysis and detection of PA by EI-GC-MS and LC-HRMS when present at a 10 µg/mL in a soil matrix featured in the 44th PT and in a glycerol-rich liquid matrix featured in the 48th Official Organization for the Prohibition of Chemical Weapons (OPCW) Proficiency Test when present at a 5 µg/mL concentration. In both scenarios, PA was successfully transformed into PIC, establishing the protocol as an additional tool for the analysis of this unnatural and unique nerve agent marker by GC-MS and LC-HRMS.

Arylsulfonamide pyrimidines as VLA-4 antagonists.

A series of (S)-2-(2-(diethylamino)-5-(N-alkyl-N-sulfonamido)pyrimidin-4-ylamino)-3-(4-(carbamoyloxy)phenyl)propanoic acid is discovered as orally available VLA-4 antagonists. Representative compounds 11b and 11p showed efficacy in multiple in vivo animal models. The in vitro selectivity of 11p is also described.

Orally available and efficacious α4ß1/α4ß7 integrin inhibitors.

A series of potent α4ß1/α4ß7 integrin inhibitors is reported, including an inhibitor 12d with remarkable oral exposure and efficacy in rat models of rheumatoid arthritis and Crohn's disease.

Analysis, identification and confirmation of synthetic opioids using chloroformate chemistry: Retrospective detection of fentanyl and acetylfentanyl in urine and plasma samples by EI-GC-MS and HR-LC-MS.

Electron Impact Gas Chromatography-Mass Spectrometry (EI-GC-MS) and High Resolution Liquid Chromatography-Mass Spectrometry (HR-LC-MS) have been used in the analysis of products arising from the trichloroethoxycarbonylation of fentanyl and acetylfentanyl in urine and plasma matrices. The method involves the initial extraction of both synthetic opioids separately from the matrices followed by detection of the unique products that arise from their reaction with 2,2,2-trichloroethoxycarbonyl chloride (Troc-Cl), namely Troc-norfentanyl and Troc-noracetylfentanyl. The optimized protocol was successfully evaluated for its efficacy at detecting these species formed from fentanyl and acetylfentanyl when present at low and high levels in urine (fentanyl: 5 and 10 ng/mL and acetylfentanyl: 20 and 100 ng/mL) and plasma (fentanyl: 10 and 20 ng/mL and acetylfentanyl: 50 and 200 ng/mL), values that reflect levels reported in overdose victims. The HR-LC-MS method's LOQ (limit of quantitation) for the Troc-norfentanyl and Troc-noracetylfentanyl products was determined to be ~10 ng/mL for both species. Even though the superiority in the detection of these species by HR-LC-MS over EI-GC-MS, the latter method proved to be important in the detection of the second product from the reaction, namely 2-phenylethyl chloride that is crucial in the determination of the original opioid. This observation highlights the importance of using complimentary analytical techniques in the analysis of a sample, whether biological or environmental in nature. The method herein serves as a complementary, qualitative confirmation for the presence of a fentanyl in collected urine, plasma and by extension other biological samples amenable to the common extraction procedures described for opioid analysis. More importantly, the method's main strength comes from its ability to react with unknown fentanyls to yield products that can be not only detected by EI-GC-MS and HR-LC-MS but can then be used to retrospectively identify an unknown fentanyl.

Radiographic and Cadaveric Analysis of Minimally Invasive Bunionectomy Osteotomy Position-"MIS Bunion Sweet Spot".

Minimally invasive surgery (MIS) is a growing technique that favors faster recovery and cosmetic results. We propose a recommended osteotomy position or "MIS Sweet Spot" to make the procedure more reproducible and lessen the learning curve to improve outcomes. A total of 211 patients from 3 surgeons between 2 different study centers were included in a retrospective radiograph measurement analysis and a cadaveric dissection to confirm the safety of nearby anatomical structures. An average distance of 2.2 cm proximal from the first metatarsophalangeal joint was found as the "Sweet Spot" to perform the transverse osteotomy. At this distance, neurovascular and tendinous structures were unharmed and the osteotomy remained extracapsular. Furthermore, an average of 10.7° of intermetatarsal angle reduction and a reduction of tibial sesamoid position of 3 points were achieved. A predictable and measurable distance for osteotomy placement will help to provide more confidence in producing the bunionectomy osteotomy with the specialized tools used in MIS and can help to reduce operative time and improve results.Level of Clinical Evidence (LOCE): 3.

Discovery of a potent, orally bioavailable pyrimidine VLA-4 antagonist effective in a sheep asthma model.

A series of N-(pyrimidin-4-yl)-phenylalanine VLA-4 antagonists is described. Optimization of substituents at the 2 and 5 positions of the pyrimidine ring gave 14, a very potent VLA-4 inhibitor which is orally active in a sheep asthma model.

Bilateral symptomatic Pacinian corpuscle hyperplasia of the adult foot.

Pacinian hyperplasia in the human body has been rarely described in the literature with most cases reported involving the hand (Fassola et al., 2019). This hyperplasia is considered a reactive lesion as opposed to a neoplasm (Satge et al., 2001), with the most common presenting complaint being pain and swelling (Fassola et al., 2019). In this study, a case of bilateral Pacinian corpuscle hyperplasia in the adult foot not previously described in the literature is presented.

Sex and occupation are salient factors associated with lateral ankle sprain risk in military tactical athletes.

OBJECTIVES: To assess the risk of lateral ankle sprain (LAS) in male and female tactical athletes across different military occupations in the US military. DESIGN: Retrospective cohort. METHODS: The Defense Medical Epidemiology Database was queried for the number of individuals with ICD-9 diagnosis codes 845.00 (sprain of ankle, unspecified) and 845.02 (calcaneofibular ligament sprain) on their initial encounter from 2006 to 2015. Relative risk (RR) and chi-square statistics were calculated assessing sex and occupational category on LAS risk. RESULTS: 272,970 enlisted males (27.9 per 1000 person-years), 56,732 enlisted females (34.5 per 1000 person-years), 24,534 male officers (12.6 per 1000 person-years), and 6020 female officers (16.4 per 1000 person-years) incurred a LAS. Enlisted females in all occupational groups were at significantly higher risk for LAS than their male counterparts (RR 1.09-1.68; p<0.001), except for Engineers (p=0.15). Female officers had consistently higher risk for LAS in all occupational groups (RR 1.10-1.42; p<0.001) compared with male officers, except Ground/Naval Gunfire (p=0.23). Contrasted with Infantry, enlisted tactical athletes in the Special Operations Forces, Mechanized/Armor, Aviation, Maintenance, and Maritime/Naval Specialties were at lower risk (RR 0.38-0.93; p<0.001), Artillery, Engineers, and Logistics Specialties were at higher risk (RR 1.04-1.18; p<0.001), and Administration, Intelligence, and Communications were no different (p=0.69). Compared with Ground/Naval Gunfire officers, Aviation officers were at significantly lower risk (RR, 0.75; p<0.001), and Engineers, Maintenance, Administration, Operations/Intelligence, and Logistics officers were at higher risk (RR, 1.08-1.20; p<0.001). CONCLUSIONS: Sex and military occupation were salient factors associated with LAS risk.

Structural modification of fentanyls for their retrospective identification by gas chromatographic analysis using chloroformate chemistry.

The one-step breakdown and derivatization of a panel of nine fentanyls to yield uniquely tagged products that can be detected by Electron Ionization Gas Chromatography-Mass Spectrometry (EI-GC-MS) is presented. The method involves the treatment of the synthetic opioids with 2,2,2-trichloroethoxycarbonyl chloride (TrocCl) at 60 °C for 3 h in dichloromethane and furnishes two products from one fentanyl molecule that can be used to retrospectively identify the original opioid. Parameters that were studied and fully optimized for the method included temperature, solvent, nature of scavenging base and reaction time. One of the two resulting products from the reaction bears the trichloroethoxycarbonyl (Troc) tag attached to the norfentanyl portion of the original opioid and greatly aids in the opioid detection and identification process. The methodology has been applied to the chemical modification of a panel of nine fentanyls and in all cases the molecular ion peak for the Troc-norfentanyl product bearing the distinctive trichloroethyl isotopic signature can be clearly observed. The method's LLOD was determined to be 10 ng/mL while its LLOQ was found to be 20 ng/mL. This methodology represents the first application of chloroformates in the chemical modification of this class of synthetic opioids that are notoriously inert to common derivatization strategies available for GC-MS analysis.

A Case of Neglected Achilles Rupture after an Ankle Sprain.

Lateral ankle sprains are common injuries seen by primary care and podiatric specialties. However, lateral ankle pain from a suspected inversion injury of the ankle may be more than a Grades I, II, or III ankle sprain. This case report illustrates a 30-year-old U.S. Navy Active Duty Service Member that was initially diagnosed with a "lateral ankle sprain". Upon subsequent follow-up with a podiatric foot and ankle surgeon, he was diagnosed with a 3-month-old chronic and neglected Achilles tendon rupture. The purpose of this manuscript is to present an uncommon and unique presentation of lateral ankle pain after injury, subsequent surgical treatment, as well as a review of the common differential diagnoses of "lateral ankle pain."

Pharmacological, pharmacokinetic, and primate analgesic efficacy profile of the novel bradykinin B1 Receptor antagonist ELN441958.

The bradykinin B(1) receptor plays a critical role in chronic pain and inflammation, although efforts to demonstrate efficacy of receptor antagonists have been hampered by species-dependent potency differences, metabolic instability, and low oral exposure of current agents. The pharmacology, pharmacokinetics, and analgesic efficacy of the novel benzamide B(1) receptor antagonist 7-chloro-2-[3-(9-pyridin-4-yl-3,9-diazaspiro[5.5]undecanecarbonyl)phenyl]-2,3-dihydro-isoindol-1-one (ELN441958) is described. ELN441958 competitively inhibited the binding of the B(1) agonist ligand [(3)H]desArg(10)-kallidin ([(3)H]DAKD) to IMR-90 human fibroblast membranes with high affinity (K(i) = 0.26 +/- 0.02 nM). ELN441958 potently antagonized DAKD (but not bradykinin)-induced calcium mobilization in IMR-90 cells, indicating that it is highly selective for B(1) over B(2) receptors. Antagonism of agonist-induced calcium responses at B(1) receptors from different species indicated that ELN441958 is selective for primate over rodent B(1) receptors with a rank order potency (K(B), nanomolar) of human (0.12 +/- 0.02) approximately rhesus monkey (0.24 +/- 0.01) > rat (1.5 +/- 0.4) > mouse (14 +/- 4). ELN441958 had good permeability and metabolic stability in vitro consistent with high oral exposure and moderate plasma half-lives in rats and rhesus monkeys. Because ELN441958 is up to 120-fold more potent at primate than at rodent B(1) receptors, it was evaluated in a primate pain model. ELN441958 dose-dependently reduced carrageenan-induced thermal hyperalgesia in a rhesus monkey tail-withdrawal model, with an ED(50) approximately 3 mg/kg s.c. Naltrexone had no effect on the antihyperalgesia produced by ELN441958, indicating a lack of involvement of opioid receptors. ELN441958 is a novel small molecule bradykinin B(1) receptor antagonist exhibiting high oral bioavailability and potent systemic efficacy in rhesus monkey inflammatory pain.