The role of intramolecular reactions and chemical degradation in the apparent biotransformation pathways of a series of SYK inhibitors.

In vitro metabolism studies of the SYK inhibitors AZ-A and AZ-B identified four unusual metabolites. M1 (m/z 411) was formed by both molecules and was common to several analogues (AZ-C to AZ-H) sharing the same core structure, appearing to derive from the complete loss of a pendent 3,4-diaminotetrahydropyran ring and pyrazole ring cleavage resulting in a non-obvious metabolite. M2-M4 were formed by AZ-A and a subset of the other compounds only and apparently resulted from a sequential loss of H2 from parent. Initial attempts to isolate M3 for identification were unsuccessful due to sample degradation and it was subsequently found that M2 and M3 underwent sequential chemical degradation steps to M4. M4 was successfully isolated and shown by mass spectrometry and NMR spectroscopy to be a tricyclic species incorporating the pyrazole and the 3,4-diaminotetrahydropyran groups. We propose that this arises from an intramolecular reaction between the primary amine on the tetrahydropyran and a putative epoxide intermediate on the adjacent pyrazole ring, evidence for which was generated in a b-mercaptoethanol trapping experiment. The loss of the THP-moiety observed in M1 was found to be enhanced in an analogue which was unable to undergo the intra-molecular reaction step leading us to propose two possible reaction pathways originating from the reactive intermediate. Ultimately, we conclude that the apparently complex and unusual metabolism of this series of compounds likely resulted from a single metabolic activation step forming an epoxide intermediate which subsequently underwent intramolecular rearrangement and/or chemical degradation to form the final observed products. Significance Statement The current work provides an unusual biotransformation example showing the potential for intramolecular reactions and chemical degradation to give the appearance of complex metabolism arising from a single primary route of metabolism.

The Disconnect in Intrinsic Clearance Determined in Human Hepatocytes and Liver Microsomes Results from Divergent Cytochrome P450 Activities.

Candidate drugs may exhibit higher unbound intrinsic clearances (CLint,u) in human liver microsomes (HLMs) relative to human hepatocytes (HHs), posing a challenge as to which value is more predictive of in vivo clearance (CL). This work was aimed at better understanding the mechanism(s) underlying this 'HLM:HH disconnect' via examination of previous explanations, including passive permeability limited CL or cofactor exhaustion in hepatocytes. A series of structurally related, passively permeable (Papps > 5 × 10-6 cm/s), 5-azaquinazolines were studied in different liver fractions, and metabolic rates and routes were determined. A subset of these compounds demonstrated a significant HLM:HH (CLint,u ratio 2-26) disconnect. Compounds were metabolized via combinations of liver cytosol aldehyde oxidase (AO), microsomal cytochrome P450 (CYP) and flavin monooxygenase (FMO). For this series, the lack of concordance between CLint,u determined in HLM and HH contrasted with an excellent correlation of AO dependent CLint,u determined in human liver cytosol[Formula: see text], r2 = 0.95, P < 0.0001). The HLM:HH disconnect for both 5-azaquinazolines and midazolam was as a result of significantly higher CYP activity in HLM and lysed HH fortified with exogenous NADPH relative to intact HH. Moreover, for the 5-azaquinazolines, the maintenance of cytosolic AO and NADPH-dependent FMO activity in HH, relative to CYP, supports the conclusion that neither substrate permeability nor intracellular NADPH for hepatocytes were limiting CLint,u Further studies are required to identify the underlying cause of the lower CYP activities in HH relative to HLM and lysed hepatocytes in the presence of exogenous NADPH. SIGNIFICANCE STATEMENT: Candidate drugs may exhibit higher intrinsic clearance in human liver microsomes relative to human hepatocytes, posing a challenge as to which value is predictive of in vivo clearance. This work demonstrates that the difference in activity determined in liver fractions results from divergent cytochrome P450 but not aldehyde oxidase or flavin monooxygenase activity. This is inconsistent with explanations including substrate permeability limitations or cofactor exhaustion and should inform the focus of further studies to understand this cytochrome P450 specific disconnect phenomenon.

Fertility preservation and realignment in transgender women.

Medical care for transgender people is multi-faceted and attention to individual reproductive aspirations and planning are an essential, yet often overlooked aspect of care. Given the impact of hormonal therapy and other gender affirmation procedures on reproductive function, extensive counselling and consideration of fertility preservation is recommended prior to their commencement. This review article explores the reproductive aspirations of transgender women and considers the current disparity between stated desires regarding utilisation of fertility preservation services. Current fertility preservation options and prospective treatments currently showing promise in the research arena are explored.

Discovery of AZD4625, a Covalent Allosteric Inhibitor of the Mutant GTPase KRASG12C.

KRAS is an archetypal high-value intractable oncology drug target. The glycine to cysteine mutation at codon 12 represents an Achilles heel that has now rendered this important GTPase druggable. Herein, we report our structure-based drug design approach that led to the identification of 21, AZD4625, a clinical development candidate for the treatment of KRASG12C positive tumors. Highlights include a quinazoline tethering strategy to lock out a bio-relevant binding conformation and an optimization strategy focused on the reduction of extrahepatic clearance mechanisms seen in preclinical species. Crystallographic analysis was also key in helping to rationalize unusual structure-activity relationship in terms of ring size and enantio-preference. AZD4625 is a highly potent and selective inhibitor of KRASG12C with an anticipated low clearance and high oral bioavailability profile in humans.

Presumed Dissent? Opt-out Organ Donation and the Exclusion of Organs and Tissues.

It is often claimed that a legitimate approach to organ donation is an opt-out system, also known as 'presumed consent', 'deemed consent', or 'deemed authorisation', whereby individuals are presumed or deemed willing to donate at least some of their organs and tissues after death unless they have explicitly refused permission. While sharing a default in favour of donation, such systems differ in several key respects, such as the role and importance assigned to the family members of prospective donors and their preferences, and exclusions and safeguards which often specify the demographic groups, purposes, or organs and tissues that will remain outside the scope of the opt-out system. Using the recent shift to opt-out in England, Scotland, and Northern Ireland as case studies, and by reference to the key goals motivating this shift across the UK, this article asks whether and, if so, why, and how, opt-out systems for post-mortem organ donation should restrict the types of organs and tissues for which consent is deemed. In other words, ought opt-out systems for PMOD presume dissent regarding the donation of certain organs and tissues?

Before and beyond trust: reliance in medical AI.

Artificial intelligence (AI) is changing healthcare and the practice of medicine as data-driven science and machine-learning technologies, in particular, are contributing to a variety of medical and clinical tasks. Such advancements have also raised many questions, especially about public trust. As a response to these concerns there has been a concentrated effort from public bodies, policy-makers and technology companies leading the way in AI to address what is identified as a "public trust deficit". This paper argues that a focus on trust as the basis upon which a relationship between this new technology and the public is built is, at best, ineffective, at worst, inappropriate or even dangerous, as it diverts attention from what is actually needed to actively warrant trust. Instead of agonising about how to facilitate trust, a type of relationship which can leave those trusting vulnerable and exposed, we argue that efforts should be focused on the difficult and dynamic process of ensuring reliance underwritten by strong legal and regulatory frameworks. From there, trust could emerge but not merely as a means to an end. Instead, as something to work in practice towards; that is, the deserved result of an ongoing ethical relationship where there is the appropriate, enforceable and reliable regulatory infrastructure in place for problems, challenges and power asymmetries to be continuously accounted for and appropriately redressed.

Optimization of an Imidazo[1,2-a]pyridine Series to Afford Highly Selective Type I1/2 Dual Mer/Axl Kinase Inhibitors with In Vivo Efficacy.

Inhibition of Mer and Axl kinases has been implicated as a potential way to improve the efficacy of current immuno-oncology therapeutics by restoring the innate immune response in the tumor microenvironment. Highly selective dual Mer/Axl kinase inhibitors are required to validate this hypothesis. Starting from hits from a DNA-encoded library screen, we optimized an imidazo[1,2-a]pyridine series using structure-based compound design to improve potency and reduce lipophilicity, resulting in a highly selective in vivo probe compound 32. We demonstrated dose-dependent in vivo efficacy and target engagement in Mer- and Axl-dependent efficacy models using two structurally differentiated and selective dual Mer/Axl inhibitors. Additionally, in vivo efficacy was observed in a preclinical MC38 immuno-oncology model in combination with anti-PD1 antibodies and ionizing radiation.

Ideal proportion of the population to be patch tested: How many should we be doing?

BACKGROUND: How many patients should we be patch testing? A previous study suggested that the minimum proportion of a population to be patch tested for allergic contact dermatitis was 1:700 annually. OBJECTIVES: To evaluate if the current minimum rate for patch testing has changed over the 20 years since the previous study in order to maximize the value. METHODS: In cooperation with the British Society for Cutaneous Allergy, a proforma for collation of retrospective data between January 2015 and December 2017 was sent to patch-test centers in the United Kingdom (UK) and the Republic of Ireland (ROI). The number of positive tests was analyzed against the proportion of population tested to see what proportion of the population would yield the greatest number of positive results. RESULTS: Responses from 11 centers showed that the minimum number needed to patch test had increased to 1:550 per head of population per year using the current criteria. CONCLUSIONS: In agreement with previous studies, we should be patch testing more people than we are. We could reduce the threshold for referral of patients we patch test to derive the most benefit from this investigation.

Microbially induced calcite precipitation performance of multiple landfill indigenous bacteria compared to a commercially available bacteria in porous media.

Microbially Induced Carbonate Precipitation (MICP) is currently viewed as one of the potential prominent processes for field applications towards the prevention of soil erosion, healing cracks in bricks, and groundwater contamination. Typically, the bacteria involved in MICP manipulate their environment leading to calcite precipitation with an enzyme such as urease, causing calcite crystals to form on the surface of grains forming cementation bonds between particles that help in reducing soil permeability and increase overall compressive strength. In this paper, the main focus is to study the MICP performance of three indigenous landfill bacteria against a well-known commercially bought MICP bacteria (Bacillus megaterium) using sand columns. In order to check the viability of the method for potential field conditions, the tests were carried out at slightly less favourable environmental conditions, i.e., at temperatures between 15-17°C and without the addition of urease enzymes. Furthermore, the sand was loose without any compaction to imitate real ground conditions. The results showed that the indigenous bacteria yielded similar permeability reduction (4.79 E-05 to 5.65 E-05) and calcium carbonate formation (14.4-14.7%) to the control bacteria (Bacillus megaterium), which had permeability reduction of 4.56 E-5 and CaCO3 of 13.6%. Also, reasonably good unconfined compressive strengths (160-258 kPa) were noted for the indigenous bacteria samples (160 kPa). SEM and XRD showed the variation of biocrystals formation mainly detected as Calcite and Vaterite. Overall, all of the indigenous bacteria performed slightly better than the control bacteria in strength, permeability, and CaCO3 precipitation. In retrospect, this study provides clear evidence that the indigenous bacteria in such environments can provide similar calcite precipitation potential as well-documented bacteria from cell culture banks. Hence, the idea of MICP field application through biostimulation of indigenous bacteria rather than bioaugmentation can become a reality in the near future.

Options for acquiring motherhood in absolute uterine factor infertility; adoption, surrogacy and uterine transplantation.

KEY CONTENT: Following the diagnosis of absolute uterine factor infertility (AUFI), women may experience considerable psychological harm as a result of a loss of reproductive function and the realisation of permanent and irreversible infertility.Adoption enables women with AUFI, and their partners, to experience social and legal parenthood, also often providing benefits for the adopted child.Surrogacy offers the opportunity to have genetically related offspring. Outcomes are generally positive in both surrogates and the children born as a result.Uterine transplantation is the only option to restore reproductive anatomy and functionality. While associated with considerable risk, it allows the experience of gestation and the achievement of biological, social and legal parenthood. LEARNING OBJECTIVES: To gain an understanding of the routes to parenthood available for women with AUFI experiencing involuntary childlessness, such as adoption, surrogacy and, most recently, uterine transplantationTo consider a suggested management plan to facilitate counselling in women with AUFI who experience involuntary childlessness. ETHICAL ISSUES: In the UK, while the number of children requiring adoption continues to increase, the number being adopted from care is decreasing.Some cultures may hold ethical or religious beliefs that surrogacy is unacceptable, and its legal position in many jurisdictions is problematic.Restrictive selection criteria and high costs may limit future availability of uterine transplantation.

Uterine Transplantation Using Living Donation: A Cross-sectional Study Assessing Perceptions, Acceptability, and Suitability.

A uterine transplantation is a nonvital, quality-of-life-enhancing solid organ transplant. Given improvements in donor risk profile and the anticipated shortage of suitable deceased donors, nondirected donation could facilitate sustainability as uterine transplantation moves from research into the clinical realm. The aim of this article is to determine perceptions and identify motivations of potential nondirected living uterus donors and assess acceptability and suitability. METHODS: A cross-sectional survey using an electronic questionnaire among women who have inquired about donating their uterus for uterine transplantation. RESULTS: The majority of respondents "strongly agreed" or "agreed" that the most prevalent motivations to donate their uterus include helping someone carry and give birth to their own baby (n = 150; 99%), helping others (n = 147; 97%), and because they no longer need their womb (n = 147; 97%). After considering risks of uterus donation, the majority were still keen to donate their uterus (n = 144; 95%), but following a process of exclusion using donor selection criteria, less than a third (n = 42; 29%) were found to be suitable to proceed. CONCLUSIONS: This study demonstrates novel insight into the motivations of women who wish to donate their uterus and displays high levels of acceptability after consideration of the risks involved. Despite the physical risk and transient impact upon ability to undertake activities of daily living, women who donate their uterus expect to gain psychological and emotional benefits from enabling another woman to gestate and give birth to their own future children. However, currently used selection criteria reduce the number of potential donors significantly.

Perceptions and Motivations for Uterus Transplant in Transgender Women.

Importance: Uterus transplant has been demonstrated to be a viable fertility-restoring treatment for women categorized as female at birth with absolute uterine factor infertility. Recent advancements, as well as considerations of fairness and equality in reproductive care, have now led to the possibility of uterus transplant being undertaken in transgender women. Objective: To investigate the reproductive aspirations of transgender women and their perceptions of uterus transplant. Design, Setting, and Participants: This cross-sectional survey study used a 27-item electronic questionnaire to investigate the reproductive aspirations of 182 transgender women older than 16 years, including their perceptions of and motivations for uterus transplant, between May 1 and November 1, 2019. Main Outcomes and Measures: Perceptions of and motivations for uterus transplant, including perceived significance of the ability to gestate, menstruate, and have a physiologically functioning vagina. Results: A total of 182 transgender women completed the questionnaire; most women (109 [60%]) were aged 20 to 29 years. Most did not have children prior to transitioning (167 [92%]) and expressed a desire to have children in the future (171 [94%]). In addition, most respondents agreed or strongly agreed that the ability to gestate and give birth to children (171 [94%]) and menstruate (161 [88%]) would enhance perceptions of their femininity. Similarly, high proportions strongly agreed or agreed that having a transplanted, functioning vagina would improve their sexual experience (163 [90%]), improve their quality of life (163 [90%]), and help them to feel like more of a woman (168 [92%]). Nearly all respondents (180 [99%]) believed that uterus transplant would lead to greater happiness in transgender women. More than three-quarters of the respondents (140 [77%]) strongly agreed or agreed that they would be more inclined to cryopreserve sperm if uterus transplant became a realistic option. Conclusions and Relevance: This study provides insights into the reproductive aspirations of transgender women and reports on their multifaceted motivation to undergo uterus transplant. The survey responses suggest that transgender women would choose to have female physiologic experiences, such as menstruation and gestation, as well as potentially having a physiologically functioning transplanted vagina. If proven feasible and safe in this setting, uterus transplant may facilitate the achievement of reproductive aspirations, improve quality of life, and further alleviate dysphoric symptoms in transgender women.

MICP as a potential sustainable technique to treat or entrap contaminants in the natural environment: A review.

In the last two decades, developments in the area of biomineralization has yielded promising results making it a potentially environmentally friendly technique for a wide range of applications in engineering and wastewater/heavy metal remediation. Microbially Induced Carbonate Precipitation (MICP) has led to numerous patented applications ranging from novel strains and nutrient sources for the precipitation of biominerals. Studies are being constantly published to optimize the process to become a promising, cost effective, ecofriendly approach when compared with the existing traditional remediation technologies which are implemented to solve multiple contamination/pollution issues. Heavy metal pollution still poses a major threat towards compromising the ecosystem. The removal of heavy metals is of high importance due to their recalcitrance and persistence in the environment. In that perspective, this paper reviews the current and most significant discoveries and applications of MICP towards the conversion of heavy metals into heavy metal carbonates and removal of calcium from contaminated media such as polluted water. It is evident from the literature survey that although heavy metal carbonate research is very effective in removal, is still in its early stages but could serve as a solution if the microorganisms are stimulated directly in the heavy metal environment.

Intracoronary near-infrared spectroscopy-role and clinical applications.

Intracoronary near-infrared spectroscopy (NIRS) has been developed and validated for the detection of lipid-rich plaque in the coronary arteries. A combined NIRS and intravascular ultrasound catheter is currently in clinical use and has an emerging role in evaluating plaques both before and after percutaneous coronary intervention. NIRS has recently been shown to positively identify both vulnerable patients and vulnerable plaques. This review focuses on the principles and image interpretation of intracoronary NIRS, as well as its clinical applications, limitations, and future directions.