Discovery of Protease-Activated Receptor 4 (PAR4)-Tethered Ligand Antagonists Using Ultralarge Virtual Screening.

Here, we demonstrate a structure-based small molecule virtual screening and lead optimization pipeline using a homology model of a difficult-to-drug G-protein-coupled receptor (GPCR) target. Protease-activated receptor 4 (PAR4) is activated by thrombin cleavage, revealing a tethered ligand that activates the receptor, making PAR4 a challenging target. A virtual screen of a make-on-demand chemical library yielded a one-hit compound. From the single-hit compound, we developed a novel series of PAR4 antagonists. Subsequent lead optimization via simultaneous virtual library searches and structure-based rational design efforts led to potent antagonists of thrombin-induced activation. Interestingly, this series of antagonists was active against PAR4 activation by the native protease thrombin cleavage but not the synthetic PAR4 agonist peptide AYPGKF.

After COVID-19: preparing staff for future surges in respiratory illness in children and improving well-being.

The coronavirus disease 2019 (COVID-19) pandemic was a challenging experience for children and young people's services, and the workforce. The Valuing All Staff Together programme was a one-year project hosted by the North West Paediatric Critical Care, Surgery in Children, Long Term Ventilation Operational Delivery Network to support teams caring for children and young people to reflect on their experiences of the COVID-19 pandemic. Using an online survey, focus groups and interviews, it gave staff the opportunity to explore and understand the effects of the pandemic and the subsequent surge in demand, including how these affected services and the emotional health and well-being of staff. This would enable better preparation for future surges in respiratory illness in terms of learning, training and development. This article describes the programme's aim, method and findings, and the main recommendations for practice.

Can an in-person hands-on applicator-based teaching session improve trainee knowledge and comfort with complex gynecologic brachytherapy?

INTRODUCTION: With the emergence of imaged-based planning and hybrid applicators the complexity of gynecologic brachytherapy has dramatically increased. Despite the known advantages of brachytherapy, notable national declines in utilization of brachytherapy have been documented. Clearly improved education in the sphere of gynecologic brachytherapy is needed. We hypothesize that a hands-on applicator-based training session would improve trainee comfort with gynecologic brachytherapy. METHODS AND MATERIALS: An in-person, applicator-based, hands-on training session was held with trainees from both radiation and gynecologic oncology programs. Trainees practiced assembling and handling applicators while receiving instruction on clinical scenarios in which various applicators are used in gynecologic cancer brachytherapy. Pre- and post-session, participants were administered an objective test of 10 pictorial-based case vignettes to quantify ability to select the correct applicator based on the interpretation of T2-weighted MR images. Participants additionally received a subjective survey to quantify comfort and experience with gynecologic brachytherapy using Likert-type question formatting. RESULTS: A total of 14 trainees participated. Most common case volume experience was 0-10 intracavitary (57%), 0-10 hybrid (71%), and 0-10 interstitial (71%). Pre-session, the most common answer to comfort level was "not comfortable still learning" for all brachytherapy types, and most common answer to largest gap in knowledge was all facets of brachytherapy. Average case-based test score was 3.5/10 pre-session versus 5.3/10 post-session (p = 0.028). Post-session, all respondents reported improved comfort level with brachytherapy. Post-session, most common answer to largest gap in knowledge was applicator/patient selection, and applicator/patient selection was also the largest area of identified improvement. 100% of participants felt repeating the session in the future would be helpful. CONCLUSIONS: Hands-on training with applicators improves both subjective and objective comfort with gynecologic brachytherapy. With 100% of participants requesting to implement this session into resident training, we suggest national opportunities might exist to expand educational processes and improve utilization of complex gynecologic brachytherapy in practice.

Efficacy of DYRK1A inhibitors in novel models of Down syndrome acute lymphoblastic leukemia.

Not available.

Longitudinal associations of daily affective dynamics with depression, generalized anxiety, and social anxiety symptoms.

BACKGROUND: Low average affect, measured using ecological momentary assessment (EMA), has been consistently linked with depression, generalized anxiety, and social anxiety, supporting trait-like negative affect as a shared underlying feature. However, while theoretical models of emotion regulation would also implicate greater variability in daily affect in these conditions, empirical evidence linking EMA of mood variability with affective disorders is mixed. We used multilevel modeling to test relationships of daily mood and mood variability with depression, generalized anxiety, and social anxiety symptoms. METHODS: Participants (N = 1004; 72.31 % female; Mage = 40.85) responded to EMA of mood 2-3×/day and completed measures of depression (PHQ-8), generalized anxiety (GAD-7), and social anxiety (SPIN) every three weeks. RESULTS: Lower mean affect predicted all symptoms at both the between-person (PHQ-8: ß = -0.486, p < 0.001; GAD-7: ß = -0.429, p < 0.001; SPIN: ß = -0.284, p < 0.001) and within-person (PHQ-8: ß = -0.219, p < 0.001; GAD-7: ß = -0.196, p < 0.001; SPIN: ß = -0.049, p < 0.001) levels. Similarly, at the between-person level, greater affective variability was linked with all three clinical symptoms (PHQ-8: ß = 0.617, p < 0.001; GAD-7: ß = 0.703, p < 0.001; SPIN: ß = 0.449, p < 0.001). However, within-person, affective variability related to depression (ß = 0.144, p < 0.001) and generalized anxiety (ß = 0.150, p < 0.001), but not social anxiety (ß = 0.006, p = 0.712). LIMITATIONS: The COVID-19 pandemic lockdown period occurred midway through the study. CONCLUSION: Findings point to common and specific emotion dynamics that characterize affective symptoms severity, with implications for affective monitoring in a clinical context.

Groebke Blackburn Bienaymé-mediated multi-component synthesis of selective HDAC6 inhibitors with anti-inflammatory properties.

Histone deacetylases (HDACs) are a class of enzymes that cleave acyl groups from lysine residues of histone and non-histone proteins. There are 18 human HDAC isoforms with different cellular targets and functions. Among them, HDAC6 was found to be overexpressed in different types of cancer. However, when used in monotherapy, HDAC6 inhibition by selective inhibitors fails to show pronounced anti-cancer effects. The HDAC6 enzyme also addresses non-histone proteins like α-tubulin and cortactin, making it important for cell migration and angiogenesis. Recently, the NLRP3 inflammasome was identified as an important regulator of inflammation and immune responses and, importantly, HDAC6 is critically involved the activation of the inflammasome. We herein report the design, synthesis and biological evaluation of a library of selective HDAC6 inhibitors. Starting from the previously published crystal structure of MAIP-032 in complex with CD2 of zHDAC6, we performed docking studies to evaluate additional possible interactions of the cap group with the L1-loop pocket. Based on the results we synthesized 13 novel HDAC6 inhibitors via the Groebke-Blackburn-Bienaymé three component reaction as the key step. Compounds 8k (HDAC1 IC50: 5.87 µM; HDAC6 IC50: 0.024 µM; selectivity factor (SF1/6): 245) and 8m (HDAC1 IC50: 3.07 µM; HDAC6 IC50: 0.026 µM; SF1/6: 118) emerged as the most potent and selective inhibitors of HDAC6 and outperformed the lead structure MAIP-032 (HDAC1 IC50: 2.20 µM; HDAC6 IC50: 0.058 µM; SF1/6: 38) both in terms of inhibitory potency and selectivity. Subsequent immunoblot analysis confirmed the high selectivity of 8k and 8m for HDAC6 in a cellular environment. While neither 8k and 8m nor the selectivity HDAC6 inhibitor tubastatin A showed antiproliferative effects in the U-87 MG glioblastoma cell line, compound 8m attenuated cell migration significantly in wound healing assays in U-87 MG cells. Moreover, in macrophages compounds 8k and 8m demonstrated significant inhibition of LPS-induced IL1B mRNA expression and TNF release. These findings suggest that our imidazo[1,2-a]pyridine-capped HDAC6 inhibitors may serve as promising candidates for the development of drugs to effectively treat NLRP3 inflammasome-driven inflammatory diseases.

Is size in the eye of the beholder? Visual estimation of penis size among transgender and cisgender people and implications for genital gender-affirming surgery and sexual medicine.

BACKGROUND: Transgender men (TM) seeking gender-affirming phalloplasty and transgender women (TW) seeking vaginoplasty and desiring insertive intercourse must consider penis size. Evidence has shown that, at least among cisgender men (CM), penile dimensions tend to be poorly estimated. In transgender patients desiring gender-affirming surgery, inaccuracy in estimation of penis dimensions may lead to unnecessary morbidity: for TW, trauma to the neovagina; for TM with excess girth, an inability to insert. Studies on the accuracy with which transgender and cisgender patients estimate penis size are limited. AIM: To assess the degree of accuracy with which CM and CW, as well as TM and TW, visually estimate the size of the human penis, including length, width, and girth. METHODS: There were 142 participants included (25 TM, 47 TW, 30 CM, and 40 CW; net mean ± SD age, 36.6 ± 11.2 years). Participants were shown these models and asked to estimate length, width, and midshaft girth by visual inspection of 6 realistic models of a penis and scrotum of varying lengths and widths. We evaluated the accuracy of the visual measurements by comparing mean perceived dimensions with the actual dimensions of each model. OUTCOMES: We used a multivariate model of all 3 bias dimensions to test for differences in average bias among gender groups (CM, CW, TM, and TW). RESULTS: TM significantly overestimated length across the longest models. TW significantly overestimated length in the longer 3 models. All groups except for TM significantly underestimated girth in at least 1 model. No groups significantly underestimated width. CM, CW, and TM significantly overestimated width in all 6 models. CLINICAL IMPLICATIONS: When transgender patients use numbers to express penis size (either in neophallus or vaginal depth based on perceived partner size), the result is likely to be larger than expected. Use of realistic penis models as a decision-making tool may help manage patient expectations and surgery decision making preoperatively and improve postoperative patient satisfaction and safety. STRENGTHS AND LIMITATIONS: To our knowledge, this is the first study to assess visual estimation in penis size in TM and CM, as well as TW and CW. The penile models in our study were shown side by side and in the flaccid state despite having dimensions more consistent with an erect penis, which may have influenced estimations across all dimensions. CONCLUSION: Men and women (cisgender and transgender) tend to significantly overestimate penis length and width.

The Relationship of Self-identified Weight Status With Perceived Mental and Physical Health.

OBJECTIVE: This study examined whether individuals with higher weight (body mass index in the overweight or obesity range) self-identified as having overweight or obesity (Ow/Ob). The study also examined whether self-identifying as having Ow/Ob was associated with perceived mental health, perceived physical health, depression, and eating disorder psychopathology. METHODS: Four study groups were created: those with Ow/Ob who self-identified as having Ow/Ob (Ow/Ob+), those with Ow/Ob who did not self-identify as having Ow/Ob (Ow/Ob-), those with core features of binge-eating disorder (BED) and Ow/Ob, and those with bulimia nervosa (BN) and Ow/Ob. Analyses of variance compared study groups on perceived health, depression, and eating disorder psychopathology. RESULTS: The BED and BN groups were more likely to self-identify as having overweight/obesity compared with Ow/Ob groups without eating disorders. The Ow/Ob- group had the best-perceived health and the lowest levels of eating disorder psychopathology and depression compared with the other groups. The Ow/Ob+ group had better perceived mental health than the BED and BN groups but did not differ significantly from the Ow/Ob- group in perceived mental health. Perceived physical health in the Ow/Ob+ group was better than in the BED group and worse than in the Ow/Ob- group. The Ow/Ob+ group had higher levels of eating disorder psychopathology than the Ow/Ob- group. CONCLUSIONS: Self-identifying as having obesity is associated with eating disorder psychopathology as well as poorer perceived mental and physical health. Providers should engage patients in discussions about their weight with the understanding that self-identifying as having overweight or obesity might indicate the presence of eating disorder psychopathology. Future clinical research should investigate the directionality or possible bidirectionality of this relationship.

Shallow-depth vaginoplasty: preoperative goals, postoperative satisfaction, and why shallow-depth vaginoplasty should be offered as a standard feminizing genital gender-affirming surgery option.

BACKGROUND: Shallow-depth vaginoplasty (SDV), also referred to as vaginoplasty without creation of a vaginal canal, is an understudied alternative to full-depth vaginoplasty (FDV), or vaginoplasty with creation of a vaginal canal. SDV is associated with fewer short- and long-term risks and shorter recovery, and does not require a lifelong commitment to vaginal dilation and douching. AIM: To describe a surgical technique for SDV that creates a dimpled introitus, together with clinical outcomes, decision-making prioritization, and satisfaction data. We hypothesize that SDV patients prioritize comparable appearance and sexual function to FDV over shorter-term risk factors, and experience high satisfaction. METHODS: We describe (1) a surgical technique for SDV; (2) the proportion of patients who underwent SDV vs. FDV, with SDV complication rates; and (3) the results of an anonymous, electronic questionnaire administered via Qualtrics that assessed SDV patient demographics, terminology preferences, prioritization of decision-guiding factors for choosing SDV over FDV, and postoperative satisfaction across various domains. OUTCOMES: A total of 110 patients underwent primary feminizing genital gender-affirming surgery at a single institution between April 2017 and July 2022: 35 (32%) of 110 underwent SDV and 75 (68%) underwent FDV. The 35 SDV patients were invited to answer the study questionnaire, of which 29 (83%) completed it (mean age 51.9 ± 16.7 years, mean body mass index 27.3 ± 5.3 kg/m2). RESULTS: All but one survey respondent met one or more of the following characteristics: (1) ≥40 years of age, (2) exclusively feminine-identifying sexual partners, and/or (3) significant aversion to performing long-term vaginal dilation and douching. Ranking of 8 decision-guiding factors revealed prioritization of long-term over short-term outcomes. Postoperatively, patients reported high satisfaction across all 3 domains. When asked if they had to choose between SDV and FDV over again, 86% reported that they would choose SDV. While 14% would choose FDV, all but one reported new interest in receptive vaginal intercourse due to finding masculine-identifying partners post-SDV surgery. A total of 27% of SDV patients experienced complications that required additional surgeries; 82% of complications were related to urinary spraying. CLINICAL IMPLICATIONS: SDV is a lower-risk alternative to FDV and is associated with reduced postoperative maintenance and high postoperative satisfaction. STRENGTHS AND LIMITATIONS: This study describes the clinical outcomes of the largest documented cohort of patients to undergo SDV to date. Limitations include recall bias due to the retrospective survey and use of nonvalidated questions attributed to the paucity of validated gender-affirming surgery questionnaires. CONCLUSION: SDV's appeal to a large subset of patients (32% in this study), low complication rate, high satisfaction, and low decisional regret suggests that this surgical option should be offered to all patients seeking feminizing genital gender-affirming surgery.

Positive affect dysregulation and its relation to binge eating size and frequency.

Negative affect is an established predictor of binge eating, yet less is known about positive affect. Low positive affect has been theorized to increase binge eating, but a better understanding is needed on the relationship between positive affect and binge eating frequency and size. Participants were 182 treatment-seeking adults (76% self-identified as female; 45% self-identified their race as Black and 40% as White; and 25% self-identified their ethnicity as Hispanic/Latino) with self-reported recurrent binge eating (≥12 binge episodes in the past 3 months). Participants completed the positive and negative affect schedule (PANAS) survey and the eating disorder examination to assess frequency of objective binge episodes (OBEs) and subjective binge episodes (SBEs) over the past 3 months. OBEs and SBEs also were combined to yield total binge episodes over the past 3 months. Independent t-tests and linear regression analyses were used to test associations between positive affect scores and binge episode size and frequencies, and to compare low versus higher positive affect on binge frequency. Additional exploratory models were conducted controlling for negative affect, identity characteristics, and socio-demographic variables. Lower positive affect was significantly associated with more frequent total binge episodes, but not OBEs and SBEs when assessed independently. Findings remained consistent when controlling for covariates and when comparing individuals with the lowest versus higher positive affect levels. Overall, results lend support to the theory that low positive affect is associated with binge eating. Increasing positive affect may be an important treatment consideration for those with recurrent binge eating.

Mood and Anxiety Disorders: Major Depressive Disorder.

Major depressive disorder (MDD) is defined as five or more of the following symptoms in the past 2 weeks, during which at least one is depressed mood or loss of interest or pleasure: depressed mood; diminished interest or pleasure in activities; significant weight loss or gain, or decreased or increased appetite; insomnia or hypersomnia; psychomotor agitation or retardation; fatigue or loss of energy; feelings of worthlessness or excessive or inappropriate guilt; poor concentration or indecisiveness; or recurrent thoughts of death or suicidal ideation, plan, or attempt. Screening for MDD is recommended in the general adult population when resources are available for diagnosis, management, and follow-up. Several screening tools are available, including the Patient Health Questionnaire-9 (PHQ-9) and Beck Depression Inventory for Primary Care (BDI-PC). Laboratory tests may be considered to assess for significant comorbidities, differential diagnoses, or contraindications to treatment. Management of MDD depends on its severity and may include psychotherapy, pharmacotherapy, or both. The drugs most commonly used are selective serotonin reuptake inhibitors. Treatment should be continued for at least 16 to 24 weeks to prevent recurrence. Referral to a psychiatrist or other mental health clinician should be considered when the diagnosis is in question or when symptoms do not improve with standard treatment.

Mood and Anxiety Disorders: Bipolar Disorder.

Bipolar I disorder affects approximately 0.4% to 1% of the global population. In the United States, bipolar-related disorders are associated with a significant economic burden because of the functional impairment they cause. Due to long wait times for access to specialist physicians and insurance issues, primary care physicians frequently manage this condition. Up to 4% of patients in primary care have bipolar disorder (BD). The diagnostic criteria for bipolar-related disorders are complex, and screening tools alone are insufficient for identification. Diagnosis involves a comprehensive clinical assessment that often requires multiple visits. Lithium continues to be the gold-standard mood-stabilizing drug for BD management and maintenance therapy in adults. Some anticonvulsants and atypical antipsychotics also have been shown to be effective for maintenance therapy. Ketamine is being studied as a possible future treatment option, but current research does not support its use. Psychotherapy, such as cognitive behavioral therapy and psychoeducation on management strategies, can be a useful adjunct therapy. Mental health clinicians can support primary care physicians in the evaluation and treatment of patients with BD.

Mood and Anxiety Disorders: Suicide.

In the United States, suicide was the cause of more than 47,500 deaths in 2019. Females attempt suicide 1.5 times more frequently than males. However, rates of completed suicide are higher in males than in females. In the US population, the suicide rate is highest in adults older than 75 years. Factors associated with an increased risk of suicide include geographic and social isolation, low access to clinical resources, unemployment, and poverty. Patients with mental disorders, including schizophrenia, major depressive disorder (MDD), bipolar disorder, and substance use disorder, are at increased risk. Directly questioning a patient about suicide has not been shown to increase the patient's risk of completing suicide. Physicians should ask patients about any suicide plans and details of timing, location, means, and any preparation for the act. The goal of pharmacotherapy in patients with suicidality is management of comorbid mood disorders, most often MDD. Esketamine nasal spray is a pharmacotherapy option for MDD management in patients with acute suicidal ideation or behavior. It is approved for use in conjunction with an oral antidepressant. Use of "no harm contracts" or "safety contracts," in which patients attest that they will not commit suicide, should not be relied on to the exclusion of a formal suicide risk assessment and thorough clinical evaluation.

Mood and Anxiety Disorders: Generalized Anxiety and Panic Disorders.

Anxiety disorders are characterized by excessive fear and worry. Generalized anxiety disorder (GAD) and panic disorder (PD) are two of the most common anxiety disorders in the United States. GAD is defined as excessive worry and anxiety that occur on most days for at least 6 months that affect daily functioning. PD is defined by recurrent unexpected panic attacks. Patients with symptoms of GAD or PD should be assessed for conditions such as hyperthyroidism, hyperparathyroidism, and cardiac arrhythmia before confirmation of an anxiety disorder diagnosis. A U.S. Preventive Services Task Force (USPSTF) draft statement recommends screening for anxiety in adults 64 years and younger, including pregnant and postpartum women. A final statement recommends screening for anxiety in children and adolescents ages 8 to 18 years. Multiple self-report tools have been validated for GAD and PD screening. The 7-item Generalized Anxiety Disorder (GAD-7) scale is an option for screening for GAD. The Panic Disorder Severity Scale (PDSS) is a 7-item tool with excellent sensitivity and specificity in screening for PD. Management with selective serotonin reuptake inhibitors and selective norepinephrine reuptake inhibitors in combination with psychotherapy has been shown to be effective for GAD and PD. Research on alternative treatments, such as psychedelic-assisted psychotherapy, is ongoing.

Unlocking Population-Specific Treatments to Render Equitable Approaches and Management in Cardiovascular Disease: Development of a Situation-Specific Theory for African American Emerging Adults.

BACKGROUND: Emerging adulthood (18-25 years old) is a distinct developmental period in which multiple life transitions pose barriers to engaging in healthy lifestyle behaviors that reduce cardiovascular disease risk. There is limited theory-based research on African American emerging adults. OBJECTIVE: This article introduces a synthesized empirically testable situation-specific theory for cardiovascular disease prevention in African American emerging adults. METHODOLOGY: Im and Meleis' integrative approach was used to develop the situation-specific theory. RESULTS: Unlocking Population-Specific Treatments to Render Equitable Approach and Management in Cardiovascular Disease is a situation-specific theory developed based on theoretical and empirical evidence and theorists' research and clinical practice experiences. DISCUSSION: African American emerging adults have multifaceted factors that influence health behaviors and healthcare needs. Unlocking Population-Specific Treatments to Render Equitable Approaches and Management in Cardiovascular Disease has the potential to inform theory-guided clinical practice and nursing research. Recommendations for integration in nursing practice, research, and policy advocacy are presented. Further critique and testing of the theory are required.

Osteoregenerative Potential of 3D-Printed Poly ε-Caprolactone Tissue Scaffolds In Vitro Using Minimally Manipulative Expansion of Primary Human Bone Marrow Stem Cells.

The repair of orthopedic and maxillofacial defects in modern medicine currently relies heavily on the use of autograft, allograft, void fillers, or other structural material composites. This study examines the in vitro osteo regenerative potential of polycaprolactone (PCL) tissue scaffolding, fabricated via a three-dimensional (3D) additive manufacturing technology, i.e., a pneumatic micro extrusion (PME) process. The objectives of this study were: (i) To examine the innate osteoinductive and osteoconductive potential of 3D-printed PCL tissue scaffolding and (ii) To perform a direct in vitro comparison of 3D-printed PCL scaffolding with allograft Allowash® cancellous bone cubes with regards to cell-scaffold interactions and biocompatibility with three primary human bone marrow (hBM) stem cell lines. This study specifically examined cell survival, cell integration, intra-scaffold cell proliferation, and differentiation of progenitor cells to investigate the potential of 3D-printed PCL scaffolds as an alternative to allograft bone material for the repair of orthopedic injuries. We found that mechanically robust PCL bone scaffolds can be fabricated via the PME process and the resulting material did not elicit detectable cytotoxicity. When the widely used osteogenic model SAOS-2 was cultured in PCL extract medium, no detectable effect was observed on cell viability or proliferation with multiple test groups showing viability ranges of 92.2% to 100% relative to a control group with a standard deviation of ±10%. In addition, we found that the honeycomb infill pattern of the 3D-printed PCL scaffold allowed for superior mesenchymal stem-cell integration, proliferation, and biomass increase. When healthy and active primary hBM cell lines, having documented in vitro growth rates with doubling times of 23.9, 24.67, and 30.94 h, were cultured directly into 3D-printed PCL scaffolds, impressive biomass increase values were observed. It was found that the PCL scaffolding material allowed for biomass increase values of 17.17%, 17.14%, and 18.18%, compared to values of 4.29% for allograph material cultured under identical parameters. It was also found that the honeycomb scaffold infill pattern was superior to the cubic and rectangular matrix structures, and provided a superior microenvironment for osteogenic and hematopoietic progenitor cell activity and auto-differentiation of primary hBM stem cells. Histological and immunohistochemical studies performed in this work confirmed the regenerative potential of PCL matrices in the orthopedic setting by displaying the integration, self-organization, and auto-differentiation of hBM progenitor cells within the matrix. Differentiation products including mineralization, self-organizing "proto-osteon" structures, and in vitro erythropoiesis were observed in conjunction with the documented expression of expected bone marrow differentiative markers including CD-99 (>70%), CD-71 (>60%), and CD-61 (>5%). All of the studies were conducted without the addition of any exogenous chemical or hormonal stimulation and exclusively utilized the abiotic and inert material polycaprolactone; setting this work apart from the vast majority of contemporary investigations into synthetic bone scaffold fabrication In summary, this study demonstrates the unique clinical potential of 3D-printed PCL scaffolds for stem cell expansion and incorporation into advanced microstructures created via PME manufacturing to generate a physiologically inert temporary bony defect graft with significant autograft features for enhanced end-stage healing.

Rosetta's Predictive Ability for Low-Affinity Ligand Binding in Fragment-Based Drug Discovery.

Fragment-based drug discovery begins with the identification of small molecules with a molecular weight of usually less than 250 Da which weakly bind to the protein of interest. This technique is challenging for computational docking methods as binding is determined by only a few specific interactions. Inaccuracies in the energy function or slight deviations in the docking pose can lead to the prediction of incorrect binding or difficulties in ranking fragments in in silico screening. Here, we test RosettaLigand by docking a series of fragments to a cysteine-depleted variant of the TIM-barrel protein, HisF (UniProtKB Q9X0C6). We compare the computational results with experimental NMR spectroscopy screens. NMR spectroscopy gives details on binding affinities of individual ligands, which allows assessment of the ligand-ranking ability using RosettaLigand and also provides feedback on the location of the binding pocket, which serves as a reliable test of RosettaLigand's ability to identify plausible binding poses. From a library screen of 3456 fragments, we identified a set of 31 ligands with intrinsic affinities to HisF with dissociation constants as low as 400 µM. The same library of fragments was blindly screened in silico. RosettaLigand was able to rank binders before non-binders with an area under the curve of the receiver operating characteristics of 0.74. The docking poses observed for binders agreed with the binding pocket identified by NMR chemical shift perturbations for all fragments. Taken together, these results provide a baseline performance of RosettaLigand in a fragment-based drug discovery setting.

Effects of Gender-affirming Hormone Therapy on Orgasm Function of Transgender Men and Women: A Long Term Follow Up.

OBJECTIVE: To assess the reported changes in orgasm quality and function of transgender men (TM) and transgender women (TW) after commencing gender-affirming hormone therapy (GAHT). METHODS: We queried potential changes in orgasm function before and after commencing GAHT (minimum 1 year) among 130 consecutive TW and 33 TM. We queried the following domains under a uniform condition (masturbation): (1) Lead-time to reach orgasm, (2) Duration of orgasm, (3) Body location of orgasm sensation, (4) Description of orgasm as either a single or multiple-peak event, (5) Duration of post-orgasm refractory period, and (6) Overall satisfaction with orgasm quality. RESULTS: Within groups by gender, TW and TM reported similar responses to our inventory before starting GAHT. After commencing GAHT, TW reported notable changes in orgasm function: increase in lead-time necessary to reach orgasm, orgasm duration, and overall orgasm satisfaction. Similarly, TM reported an increase in duration of orgasm and increased overall satisfaction with orgasm quality. Over half of the TW reported experiencing orgasms in new/additional body locations. Additionally, prior to commencing GAHT, the majority of TM and TW patients reported their orgasms as a short, single-peak event but following GAHT these same patients reported longer and protracted multiple-peak orgasms. CONCLUSIONS: GAHT has the potential to positively improve orgasm quality for transgender patients undergoing gender transition. It is important to share such data with patients prospectively before treatments.

The bony cap and its distinction from the distal phalanx in humans, cats, and horses.

It has been recognized as early as the Victorian era that the apex of the distal phalanx has a distinct embryological development from the main shaft of the distal phalanx. Recent studies in regenerative medicine have placed an emphasis on the role of the apex of the distal phalanx in bone regrowth. Despite knowledge about the unique aspects of the distal phalanx, all phalanges are often treated as equivalent. Our morphological study reiterates and highlights the special anatomical and embryological properties of the apex of the distal phalanx, and names the apex "the bony cap" to distinguish it. We posit that the distal phalanx shaft is endochondral, while the bony cap is intramembranous and derived from the ectodermal wall. During development, the bony cap may be a separate structure that will fuse to the endochondral distal phalanx in the adult, as it ossifies well before the distal phalanges across taxa. Our study describes and revives the identity of the bony cap, and we identify it in three mammalian species: humans, cats, and horses (Homo sapiens, Felis catus domestica, and Equus caballus). During the embryonic period, we show the bony cap has a thimble-like shape that surrounds the proximal endochondral distal phalanx. The bony cap may thus play an inductive role in the differentiation of the corresponding nail, claw, or hoof (keratin structures) of the digit. When it is not present or develops erroneously, the corresponding keratin structures are affected, and regeneration is inhibited. By terming the bony cap, we hope to inspire more attention to its distinct identity and role in regeneration.