Repeated closed-head mild traumatic brain injury-induced inflammation is associated with nociceptive sensitization.

BACKGROUND: Individuals who have experienced mild traumatic brain injuries (mTBIs) suffer from several comorbidities, including chronic pain. Despite extensive studies investigating the underlying mechanisms of mTBI-associated chronic pain, the role of inflammation in long-term pain after mTBIs is not fully elucidated. Given the shifting dynamics of inflammation, it is important to understand the spatial-longitudinal changes in inflammatory processes following mTBIs and their effects on TBI-related pain. METHODS: We utilized a recently developed transgenic caspase-1 luciferase reporter mouse model to monitor caspase-1 activation through a thinned skull window in the in vivo setting following three closed-head mTBI events. Organotypic coronal brain slice cultures and acutely dissociated dorsal root ganglion (DRG) cells provided tissue-relevant context of inflammation signal. Mechanical allodynia was assessed by mechanical withdrawal threshold to von Frey and thermal hyperalgesia withdrawal latency to radiant heat. Mouse grimace scale (MGS) was used to detect spontaneous or non-evoked pain. In some experiments, mice were prophylactically treated with MCC950, a potent small molecule inhibitor of NLRP3 inflammasome assembly to inhibit injury-induced inflammatory signaling. Bioluminescence spatiotemporal dynamics were quantified in the head and hind paws, and caspase-1 activation was confirmed by immunoblot. Immunofluorescence staining was used to monitor the progression of astrogliosis and microglial activation in ex vivo brain tissue following repetitive closed-head mTBIs. RESULTS: Mice with repetitive closed-head mTBIs exhibited significant increases of the bioluminescence signals within the brain and paws in vivo for at least one week after each injury. Consistently, immunoblotting and immunofluorescence experiments confirmed that mTBIs led to caspase-1 activation, astrogliosis, and microgliosis. Persistent changes in MGS and hind paw withdrawal thresholds, indicative of pain states, were observed post-injury in the same mTBI animals in vivo. We also observed enhanced inflammatory responses in ex vivo brain slice preparations and DRG for at least 3 days following mTBIs. In vivo treatment with MCC950 significantly reduced caspase-1 activation-associated bioluminescent signals in vivo and decreased stimulus-evoked and non-stimulus evoked nociception. CONCLUSIONS: Our findings suggest that the inflammatory states in the brain and peripheral nervous system following repeated mTBIs are coincidental with the development of nociceptive sensitization, and that these events can be significantly reduced by inhibition of NLRP3 inflammasome activation.

The role of ion-lipid interactions and lipid packing in transient defects caused by phenolic compounds.

The transient disruption of membranes for the passive permeation of ions or small molecules is a complex process relevant to understanding physiological processes and biotechnology applications. Phenolic compounds are widely studied for their antioxidant and antimicrobial properties, and some of these activities are based on the interactions of the phenolic compound with membranes. Ions are ubiquitous in cells and are known to alter the structure of phospholipid bilayers. Yet, ion-lipid interactions are usually ignored when studying the membrane-altering properties of phenolic compounds. This study aims to assess the role of Ca2+ ions on the membrane-disrupting activity of two phenolic acids and to highlight the role of local changes in lipid packing in forming transient defects or pores. Results from tethered bilayer lipid membrane electrical impedance spectroscopy experiments showed that Ca2+ significantly reduces membrane disruption by caffeic acid methyl ester and caffeic acid. As phenolic acids are known metal chelators, we used UV-vis and fluorescence spectroscopy to exclude the possibility that Ca2+ interferes with membrane disruption by binding to the phenolic compound and subsequently preventing membrane binding. Molecular dynamics simulations showed that Ca2+ but not caffeic acid methyl ester or caffeic acid increases lipid packing in POPC bilayers. The combined data confirm that Ca2+ reduces the membrane-disrupting activity of the phenolic compounds, and that Ca2+-induced changes to lipid packing govern this effect. We discuss our data in the context of ion-induced pores and transient defects and how lipid packing affects membrane disruption by small molecules.

The TRPC6 inhibitor, larixyl acetate, is effective in protecting against traumatic brain injury-induced systemic endothelial dysfunction.

BACKGROUND: The incidence of traumatic brain injuries (TBIs) is on the rise in the USA. Concussions, or mild TBIs without skull fracture, account for about 75% of all TBIs. Mild TBIs (mTBIs) lead to memory and cognitive deficits, headaches, intraocular pressure rises, axonal degeneration, neuroinflammation, and an array of cerebrovascular dysfunctions, including increased vascular permeability and decreased cerebral blood flow. It has been recently reported that besides vascular dysfunction in the cerebral circulation, mTBI may also cause a significant impairment of endothelial function in the systemic circulation, at least within mesenteric microvessels. In this study, we investigated whether mTBI affects endothelial function in aortas and determined the contribution of transient receptor potential canonical (TRPC) channels to modulating mTBI-associated endothelial dysfunction. METHODS: We used a model of closed-head mTBI in C57BL/6, 129S, 129S-C57BL/6-F2 mice, and 129S-TRPC1 and 129S-C57BL/6-TRPC6 knockout mice to determine the effect of mTBI on endothelial function in mouse aortas employing ex vivo isometric tension measurements. Aortic tissue was also analyzed using immunofluorescence and qRT-PCR for TRPC6 expression following mTBI. RESULTS: We show that in various strains of mice, mTBI induces a pronounced and long-lasting endothelial dysfunction in the aorta. Ablation of TRPC6 protects mice from mTBI-associated aortic endothelial dysfunction, while TRPC1 ablation does not impact brain injury-induced endothelial impairment in the aorta. Consistent with a role of TRPC6 activation following mTBI, we observed improved endothelial function in wild type control mice subjected to mTBI following 7-day in vivo treatment with larixyl acetate, an inhibitor of TRPC6 channels. Conversely, in vitro treatment with the pro-inflammatory endotoxin lipopolysaccharide, which activates endothelial TRPC6 in a Toll-like receptor type 4 (TLR4)-dependent manner, worsened aortic endothelial dysfunction in wild type mice. Lipopolysaccharide treatment in vitro failed to elicit endothelial dysfunction in TRPC6 knockout mice. No change in endothelial TRPC6 expression was observed 7 days following TBI. CONCLUSIONS: These data suggest that TRPC6 activation may be critical for inducing endothelial dysfunction following closed-head mTBI and that pharmacological inhibition of the channel may be a feasible therapeutic strategy for preventing mTBI-associated systemic endothelial dysfunction.

Influences on the access to and use of formal community care by people with dementia and their informal caregivers: a scoping review.

BACKGROUND: The literature describes the obstacles to sufficient care faced by people with dementia and their informal caregivers. Although factors influencing access and utilisation are frequently studied, the body of knowledge lacks an overview of aspects related to influence. The frequently used Behavioural Model of Health Care Use (BM) could be used to structure and explain these aspects. An adaptation of the BM emphasises psychosocial influences and appears to enrich the understanding of the use of long-term care for dementia. METHODS: We conducted a scoping review with the aim of providing an overview of the aspects influencing the access to and utilisation of formal community care in dementia. Our search covered the PubMed, CINAHL, Social Science Citation Index and PsychInfo databases, as well as grey literature. Two researchers assessed the full texts for eligibility. A data extraction form was developed and tested. We analysed the main topics investigated by the studies and mapped and described the investigated psychosocial aspects according to the BM after narratively summarising the findings. We used the Mixed Method Appraisal Tool (MMAT) to critically appraise the included studies. RESULTS: A total of 94 studies were included: n = 55 with quantitative designs, 35 with qualitative designs and four with mixed methods. The studies investigated different services, mainly focusing on health care services. One third of the studies provided information regarding the severity of dementia. The most frequently investigated main topics were ethnicity and attitudes towards services. Psychosocial aspects were frequently investigated, although few studies considered the perspectives of people with dementia. Approximately half of the studies reported a theoretical framework. The adapted BM facilitated the structuring and description of psychosocial aspects. However, this instrument did not address topics beyond the scope of psychosocial aspects, such as sociodemographic characteristics. CONCLUSIONS: The access to and utilisation of formal community care for dementia can only be partly explained by individual influencing aspects. Therefore, a theoretical framework would likely help to describe this complex subject. Our findings indicate that the psychosocial categories of the adapted BM enriched the original BM, and that people with dementia should more often be included in healthcare service research to ensure a better understanding of the barriers to accessing formal community care.

Tyro3 Modulates Mertk-Associated Retinal Degeneration.

Inherited photoreceptor degenerations (IPDs) are the most genetically heterogeneous of Mendelian diseases. Many IPDs exhibit substantial phenotypic variability, but the basis is usually unknown. Mutations in MERTK cause recessive IPD phenotypes associated with the RP38 locus. We have identified a murine genetic modifier of Mertk-associated photoreceptor degeneration, the C57BL/6 (B6) allele of which acts as a suppressor. Photoreceptors degenerate rapidly in Mertk-deficient animals homozygous for the 129P2/Ola (129) modifier allele, whereas animals heterozygous for B6 and 129 modifier alleles exhibit an unusual intermixing of degenerating and preserved retinal regions, with females more severely affected than males. Mertk-deficient mice homozygous for the B6 modifier allele display degeneration only in the far periphery, even at 8 months of age, and have improved retinal function compared to animals homozygous for the 129 allele. We genetically mapped the modifier to an approximately 2-megabase critical interval that includes Tyro3, a paralog of Mertk. Tyro3 expression in the outer retina varies with modifier genotype in a manner characteristic of a cis-acting expression quantitative trait locus (eQTL), with the B6 allele conferring an approximately three-fold higher expression level. Loss of Tyro3 function accelerates the pace of photoreceptor degeneration in Mertk knockout mice, and TYRO3 protein is more abundant in the retinal pigment epithelium (RPE) adjacent to preserved central retinal regions of Mertk knockout mice homozygous for the B6 modifier allele. Endogenous human TYRO3 protein co-localizes with nascent photoreceptor outer segment (POS) phagosomes in a primary RPE cell culture assay, and expression of murine Tyro3 in cultured cells stimulates phagocytic ingestion of POS. Our findings demonstrate that Tyro3 gene dosage modulates Mertk-associated retinal degeneration, provide strong evidence for a direct role for TYRO3 in RPE phagocytosis, and suggest that an eQTL can modify a recessive IPD.

ANALYSIS OF HISTORICAL MEDICAL RECORDS OF CALIFORNIA CONDORS ( GYMNOGYPS CALIFORNIANUS) ADMITTED FOR LEAD EXPOSURE TO THE LOS ANGELES ZOO AND BOTANICAL GARDENS BETWEEN 1997 AND 2012: A CASE SERIES STUDY.

Lead toxicosis remains the primary cause of death in wild populations of California condors ( Gymnogyps californianus). Many condors require medical intervention with lead chelation therapy, among other conservation measures, to survive in the wild. An analysis of historical medical records of California condors admitted for lead exposure to the Los Angeles Zoo and Botanical Gardens (LA Zoo) between 1997 and 2012 was performed to investigate clinical presentation, radiographic findings, and treatment along with the potential impact of these factors on recovery and successful release back into the wild. Of 100 individual condors presented to the LA Zoo for suspected lead toxicosis during this period, 84 condors had records for initial laboratory blood lead levels. For these 84 condors (40 [47.6%] females and 44 [52.4%] males), 277 initial laboratory blood lead levels in total were recorded because of repeated admissions. Thirty-two (38%) condors were admitted once to the zoo and 62% were admitted two or more times. Clinical signs were not observed in 87.5% of the condors admitted with median blood lead concentrations of 26 µg/dl. Of the radiographs taken on initial presentation, 65% did not show evidence of gastrointestinal metallic foreign bodies. Various treatments protocols with edetatum calcium disodium, dimercaptosuccinic acid, and lactated Ringer's solution were documented in the medical records. Of the 277 admissions, 154 admissions had a recorded outcome posttreatment of which 140 (91%) admissions were released back to the wild. This study contributes to a better understanding of how intervention and therapeutic approaches have been essential for the recovery, release, and sustainability of these birds as a wild population. Consistency in data collection of California condors admitted for diagnosis and treatment of lead toxicosis is needed to better assess the impacts of medical interventions.

[Nursing home placement of people with dementia: a secondary analysis of qualitative data and literature review on perspectives of informal caregivers and healthcare professionals]. / Umzug von Menschen mit Demenz in ein Pflegeheim.

Background: Nursing home placement of people with dementia can become necessary when informal care is no longer sufficient. Informal carers experience the transition period as an additional burden. Aim: Experiences and views of informal carers and healthcare professionals regarding the transition from people with dementia to a nursing home are investigated to improve the support for informal carers. Method: This secondary analysis included data from all five focus groups with n = 30 informal carers and healthcare professionals conducted as part of the "RightTimePlaceCare" project. To supplement the material which resulted from a single interview question, a literature analysis with the same focus was conducted. Results: The merged results indicated that informal carers needed professional support early on at home until after the nursing home placement. Concerns regarding nursing homes, financial aspects and family related issues were important aspects in the decision making. Healthcare professionals recommended provision of early guidance regarding those matters and making own experiences with nursing homes. Healthcare professionals should serve as mediators during the transition process and improve the collaboration between service providers. Conclusions: Empowering families to make informed choices could be facilitated by offering advice at home about their options for formal support services, financial support, and housing solutions. Healthcare professionals should support caregivers to make a decision, coordinate the placement and to cope with the new situation.

Discovery and optimization of 2-pyridinone aminal integrase strand transfer inhibitors for the treatment of HIV.

HIV integrase strand transfer inhibitors (InSTIs) represent an important class of antiviral therapeutics with proven efficacy and excellent tolerability for the treatment of HIV infections. In 2007, Raltegravir became the first marketed strand transfer inhibitor pioneering the way to a first-line therapy for treatment-naïve patients. Challenges with this class of therapeutics remain, including frequency of the dosing regimen and the genetic barrier to resistance. To address these issues, research towards next-generation integrase inhibitors has focused on imparting potency against RAL-resistent mutants and improving pharmacokinetic profiles. Herein, we detail medicinal chemistry efforts on a novel class of 2-pyridinone aminal InSTIs, inpsired by MK-0536, which led to the discovery of important lead molecules for our program. Systematic optimization carried out at the amide and aminal positions on the periphery of the core provided the necessary balance of antiviral activity and physiochemical properties. These efforts led to a novel aminal lead compound with the desired virological profile and preclinical pharmacokinetic profile to support a once-daily human dose prediction.

Discovery of bicyclic pyrazoles as class III histone deacetylase SIRT1 and SIRT2 inhibitors.

A series of bicyclic pyrazole carboxamides was synthesized and tested for inhibitory activity against the class III deacetylase sirtuin enzymes. Moderate to low micromolar inhibitory activities were obtained against SIRT1 and SIRT2. These bicyclic pyrazole compounds represent a new class of sirtuin inhibitors with a preference for SIRT1 over SIRT2.

Critical role of the hippocampus in memory for elapsed time.

Episodic memory includes information about how long ago specific events occurred. Since most of our experiences have overlapping elements, remembering this temporal context is crucial for distinguishing individual episodes. The discovery of timing signals in hippocampal neurons, including evidence of "time cells" and of gradual changes in ensemble activity over long timescales, strongly suggests that the hippocampus is important for this capacity. However, behavioral evidence that the hippocampus is critical for the memory of elapsed time is lacking. This is possibly because previous studies have used time durations in the range of seconds when assessing hippocampal dependence, a timescale known to require corticostriatal circuits. Here we developed a nonspatial paradigm to test the hypothesis that the hippocampus is critical for keeping track of elapsed time over several minutes. We report that rats have a robust ability to remember durations at this timescale. We then determined the role of the hippocampus using infusions of fluorophore-conjugated muscimol, a GABAA agonist. We found that the hippocampus was essential for discriminating smaller, but not larger, temporal differences (measured in log units), consistent with a role in temporal pattern separation. Importantly, this effect was observed at long (minutes) but not short (seconds) timescales, suggesting an interplay of temporal resolution and timescale in determining hippocampal dependence. These results offer compelling evidence that the hippocampus plays a critical role in remembering how long ago events occurred.

Discovery of MK-1439, an orally bioavailable non-nucleoside reverse transcriptase inhibitor potent against a wide range of resistant mutant HIV viruses.

The optimization of a novel series of non-nucleoside reverse transcriptase inhibitors (NNRTI) led to the identification of pyridone 36. In cell cultures, this new NNRTI shows a superior potency profile against a range of wild type and clinically relevant, resistant mutant HIV viruses. The overall favorable preclinical pharmacokinetic profile of 36 led to the prediction of a once daily low dose regimen in human. NNRTI 36, now known as MK-1439, is currently in clinical development for the treatment of HIV infection.

Compliance with trial registration in five core journals of clinical geriatrics: a survey of original publications on randomised controlled trials from 2008 to 2012.

OBJECTIVE: to assess the proportion of registered randomised controlled trials in five core clinical geriatric journals and to analyse whether registered study outcomes correspond with published outcomes. DESIGN: survey of original papers published 2008 to 2012. METHODS: two independent reviewers retrieved the sample through search in the web-based archives of Age and Ageing, the Journal of the American Geriatric Society, the American Journal of Geriatric Psychiatry, the Journal of the American Medical Directors Association and International Psychogeriatrics. Data extraction was performed by two independent reviewers using a pre-tested 13-item checklist. Registration status was checked and information provided in registers compared with information presented in the original publication. A third reviewer was consulted if no consensus could be reached. RESULTS: the sample comprised 220 original publications on randomised controlled trials. A total of 140 (63.6%) were registered. Registration was in accordance with the ICMJE requirements in 54 out of 140 registered trials (38.6%). Less than one-third of registered papers (n = 40) reported on all study outcomes listed in the study register. In 74 out of the 80 non-registered trials, the missing registration was not declared in the publication. There was no consistent upward trend towards higher registration compliance throughout journals and years. CONCLUSION: our survey shows that prospective trial registration and compliance between outcomes declared in the registry and reported in the publication is poor. Concerted action of authors, editors and peer-reviewers is overdue aimed to irreversibly implement the imperative of registration of randomised controlled trials and complete outcome reporting.

The SOS1 Inhibitor MRTX0902 Blocks KRAS Activation and Demonstrates Antitumor Activity in Cancers Dependent on KRAS Nucleotide Loading.

KRAS is the most frequently mutated oncogene in human cancer and facilitates uncontrolled growth through hyperactivation of the receptor tyrosine kinase (RTK)/mitogen-activated protein kinase (MAPK) pathway. The Son of Sevenless homolog 1 (SOS1) protein functions as a guanine nucleotide exchange factor (GEF) for the RAS subfamily of small GTPases and represents a druggable target in the pathway. Using a structure-based drug discovery approach, MRTX0902 was identified as a selective and potent SOS1 inhibitor that disrupts the KRAS:SOS1 protein-protein interaction to prevent SOS1-mediated nucleotide exchange on KRAS and translates into an anti-proliferative effect in cancer cell lines with genetic alterations of the KRAS-MAPK pathway. MRTX0902 augmented the antitumor activity of the KRAS G12C inhibitor adagrasib when dosed in combination in eight out of 12 KRAS G12C-mutant human non-small cell lung cancer and colorectal cancer xenograft models. Pharmacogenomic profiling in preclinical models identified cell cycle genes and the SOS2 homolog as genetic co-dependencies and implicated tumor suppressor genes (NF1 and PTEN) in resistance following combination treatment. Lastly, combined vertical inhibition of RTK/MAPK pathway signaling by MRTX0902 with inhibitors of EGFR or RAF/MEK led to greater downregulation of pathway signaling and improved antitumor responses in KRAS-MAPK pathway-mutant models. These studies demonstrate the potential clinical application of dual inhibition of SOS1 and KRAS G12C and additional SOS1 combination strategies that will aide in the understanding of SOS1 and RTK/MAPK biology in targeted cancer therapy.

Discovery of Pyridopyrimidinones that Selectively Inhibit the H1047R PI3Kα Mutant Protein.

The H1047R mutation of PIK3CA is highly prevalent in breast cancers and other solid tumors. Selectively targeting PI3KαH1047R over PI3KαWT is crucial due to the role that PI3KαWT plays in normal cellular processes, including glucose homeostasis. Currently, only one PI3KαH1047R-selective inhibitor has progressed into clinical trials, while three pan mutant (H1047R, H1047L, H1047Y, E542K, and E545K) selective PI3Kα inhibitors have also reached the clinical stage. Herein, we report the design and discovery of a series of pyridopyrimidinones that inhibit PI3KαH1047R with high selectivity over PI3KαWT, resulting in the discovery of compound 17. When dosed in the HCC1954 tumor model in mice, 17 provided tumor regressions and a clear pharmacodynamic response. X-ray cocrystal structures from several PI3Kα inhibitors were obtained, revealing three distinct binding modes within PI3KαH1047R including a previously reported cryptic pocket in the C-terminus of the kinase domain wherein we observe a ligand-induced interaction with Arg1047.

Nanoparticle film assemblies as platforms for electrochemical biosensing--factors affecting the amperometric signal enhancement of hydrogen peroxide.

Factors affecting the enhanced amperometric signal observed at electrodes modified with polyelectrolyte-gold nanoparticle (Au-NP) composite films, which are potential interfaces for first-generation biosensors, were systematically investigated and optimized for hydrogen peroxide (H2O2) detection. Polyelectrolyte multilayer films embedded with citrate-stabilized gold nanoparticles exhibited high sensitivity toward the oxidation of H2O2. From this Au-NP film assembly, the importance of Au-NP ligand protection, film permeability, the density of Au-NPs within the film, and electronic coupling between Au-NPs (interparticle) and between the film and the electrode (interfacial) were evaluated. Using alternative Au-NPs, including those stabilized with thiols, polymers, and bulky ligands, suggests that the amperometric enhancement of H2O2 is optimized at poly-L-lysine-linked film assemblies embedded with Au-NPs possessing small, charged, and conductive (conjugated) peripheral ligands. As a potential application of these Au-NP film assemblies, an enhanced amperometric signal for H2O2 oxidation was shown for modified "needle" electrodes. The overall aim of this research is to gain a greater understanding of designing electrochemical sensing strategies that incorporate Au-NPs and target specific analytes.

Sclerosing Mesenteritis Managed Conservatively With Prednisone.

The authors present the case of a middle-aged lady with two weeks of abdominal pain. Computed tomography imaging revealed sclerosing mesenteritis. Sclerosing mesenteritis is also known as mesenteric panniculitis and is a chronic fibrosing inflammatory disease that primarily affects the adipose tissue of the mesentery in the small intestine and colon. The clinical presentation, imaging findings, differential diagnosis, and therapeutic management are presented in this report. In our patient's case, she was able to be managed conservatively, without the need for surgery. This reflects the most benign and self-limiting natural history of the disease.

Effectiveness of an individually tailored complex intervention to improve activities and participation in nursing home residents with joint contractures (JointConEval): a multicentre pragmatic cluster-randomised controlled trial.

OBJECTIVE: This study aims to examine the effects of the individually tailored complex intervention Participation Enabling Care in Nursing (PECAN) on activities and participation of residents with joint contractures. DESIGN: Multicentre pragmatic cluster-randomised controlled trial. SETTING: 35 nursing homes in Germany (August 2018-February 2020). PARTICIPANTS: 562 nursing home residents aged ≥65 years with ≥1 major joint contracture (303 intervention group, 259 control group). INTERVENTIONS: Nursing homes were randomised to PECAN (18 clusters) or optimised standard care (17 clusters) with researcher-concealed cluster allocation by facsimile. The intervention targeted impairments in activities and participation. Implementation included training and support for selected staff. Control group clusters received brief information. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary endpoint PaArticular Scales combined residents' activities and participation at 12 months. The secondary outcome comprised quality of life. Safety measures were falls, fall-related consequences and physical restraints. Residents, staff and researchers were unblinded. Data collection, data entry and statistical analysis were blinded. Primary analyses were intention-to-treat at cluster level and individual level using a generalised mixed-effect regression model and imputation of missing data. RESULTS: Primary outcome analyses included 301 intervention group residents and 259 control group residents. The mean change on the Activities Scale was -1.47 points (SD 12.2) in the intervention group and 0.196 points (SD 12.5) in the control group and -3.87 points (SD 19.7) vs -3.18 points (SD 20.8) on the Participation Scale. The mean differences of changes between the groups were not statistically significant: Activities Scale: -1.72 (97.5% CI -6.05 to 2.61); Participation Scale: -1.24 (97.5% CI -7.02 to 4.45). We found no significant difference in the secondary outcome and no effects on safety measures. CONCLUSION: The complex intervention did not improve the activities and participation of nursing home residents on the PaArticular Scales at 12 months. Current nursing conditions in Germany may hamper implementation. TRIAL REGISTRATION NUMBER: DRKS00015185.

Demographic, Health and Lifestyle Factors Associated with the Metabolome in Older Women.

Demographic and clinical factors influence the metabolome. The discovery and validation of disease biomarkers are often challenged by potential confounding effects from such factors. To address this challenge, we investigated the magnitude of the correlation between serum and urine metabolites and demographic and clinical parameters in a well-characterized observational cohort of 444 post-menopausal women participating in the Women's Health Initiative (WHI). Using LC-MS and lipidomics, we measured 157 aqueous metabolites and 756 lipid species across 13 lipid classes in serum, along with 195 metabolites detected by GC-MS and NMR in urine and evaluated their correlations with 29 potential disease risk factors, including demographic, dietary and lifestyle factors, and medication use. After controlling for multiple testing (FDR < 0.01), we found that log-transformed metabolites were mainly associated with age, BMI, alcohol intake, race, sample storage time (urine only), and dietary supplement use. Statistically significant correlations were in the absolute range of 0.2-0.6, with the majority falling below 0.4. Incorporation of important potential confounding factors in metabolite and disease association analyses may lead to improved statistical power as well as reduced false discovery rates in a variety of data analysis settings.

"Mobilizing our leaders": A multi-country qualitative study to increase the representation of women in global health leadership.

INTRODUCTION: Women play an essential role in health care delivery, and it is vital that they have equal representation in health leadership for equity, innovation, and the strengthening of health systems globally. Yet women remain vastly underrepresented in global health leadership positions, providing a clear example of the deeply rooted power imbalances that are central to the calls to decolonize global health. We conducted a multi-country study in Haiti, Tanzania, India, and the USA to examine gender-based challenges to career advancement for women in the global health workforce. Quantitative data on the type and prevalence of gender-based challenges has been previously reported. In this study, we analyze qualitative data collected through focus group discussions and in-depth interviews to understand women's experiences of gender-based obstacles to career advancement, their perceptions of underlying drivers, and perspectives on effective solutions. Guided by an adaptation of the Social Action Theory, we conducted focus group discussions and in-depth interviews with women at 4 major academic centers for clinical care and research in Haiti, India, Tanzania, and the United States. In total, 85 women participated in focus groups and 15 also participated in in-depth interviews. Discussions and interviews were conducted in the local language, by an experienced local facilitator unaffiliated with the participating institution, between 2017 and 2018. Discussions were recorded, transcribed, and translated. Data were analyzed by interpretive phenomenological methods for emergent themes. Three transcendent themes on gender-based challenges were identified: 1) cultural power imbalance, referring to the prevailing norms and engrained assumptions that women are less capable than men and that women's primary responsibility should be to their families; 2) institutional power imbalance, referring to the systematic gender bias upheld by existing leadership and power structures, and ranging from exclusion from career development opportunities to sexual harassment and assault; and 3) restricted agency, referring to women's limited ability to change their circumstances because of unequal cultural and institutional structures. Participants also described local, actionable solutions to address these barriers. These included: 1) formal reporting systems for sexual harassment and assault; 2) peer support and mentorship; and 3) accessible leadership training and mandatory gender equity training. Participants proposed feasible strategies to address gender-based challenges that could improve women's retention in health careers and foster their rise to leadership. Increasing the representation of women in global health leadership positions responds directly to efforts to decolonize global health and is integral to strengthening health systems and improving health outcomes for women and children worldwide.