A translational murine model of aseptic loosening with osseointegration failure.

An in vivo animal model of a weight-bearing intra-articular implant is crucial to the study of implant osseointegration and aseptic loosening caused by osseointegration failure. Osseointegration, defined as a direct structural and functional attachment between living bone tissue and the surface of a load-carrying implant, is essential for implant stability and considered a prerequisite for the long-term clinical success of implants in total joint arthroplasty. Compared to large animal models, murine models offer extensive genetic tools for tracing cell differentiation and proliferation. The 18- to 22-week-old C57BL/6J background mice underwent either press-fitted or loose implantation of a titanium implant, achieving osseointegration or fibrous integration. A protocol was developed for both versions of the procedure, including a description of the relevant anatomy. Samples were subjected to microcomputed tomography and underwent biomechanical testing to access osseointegration. Lastly, samples were fixed and embedded for histological evaluation. The absence of mineralized tissue and weakened maximum pull-out force in loose implantation samples indicated that these implants were less mechanically stable compared to the control at 4 weeks postoperation. Histological analysis demonstrated extensive fibrotic tissue in the peri-implant area of loose implantation samples and excellent implant osseointegration in press-fitted samples at 4 weeks. Both mechanically stable and unstable hemiarthroplasty models with either osseous ingrowth or a robust periprosthetic fibrosis were achieved in mice. We hope that this model can help address current limitations for in vivo study of aseptic loosening and lead to necessary translational benefits.

The Infected Polypropylene Mesh: When Does Biofilm Form and Which Antiseptic Solution Most Effectively Removes It?

BACKGROUND: Polypropylene (PPE) mesh is commonly utilized to reconstruct catastrophic extensor mechanism disruptions in revision total knee arthroplasty. Unfortunately, these procedures are associated with a high rate of periprosthetic joint infection. The purpose of the current study was to: 1) visualize and quantify the progression of bacterial biofilm growth on PPE-mesh; and 2) determine which antiseptic solutions effectively remove viable bacteria. METHODS: Knitted PPE mesh samples were cultured with either methicillin-sensitive Staphylococcus aureus (MSSA) or Escherichia coli (E. coli) for 7 days, with regular quantification of colony forming units (CFUs) and visualization using scanning electron microscopy to identify maturity. Immature (24 hour) and mature (72 hour) biofilm was treated with one of 5 commercial antiseptics for 3 minutes. A 0.05% chlorhexidine gluconate, a surfactant-based formulation of ethanol, acetic acid, sodium acetate, benzalkonium chloride, diluted povidone-iodine (0.35%), undiluted (10%) povidone-iodine, and 1:1 combination of 10% povidone-iodine and 3% hydrogen peroxide. A 3-log reduction in CFUs compared to saline was considered clinically meaningful. RESULTS: The CFU counts plateaued, indicating maturity, at 72 hours for both MSSA and E. coli. The scanning electron microscopy confirmed confluent biofilm formation after 72 hours. The 10% povidone-iodine was clinically effective against all MSSA biofilms and immature E. coli biofilms. The 10% povidone-iodine with hydrogen peroxide was effective in all conditions. Only 10% povidone iodine formulations produced significantly (P < .0083) reduced CFU counts against mature biofilms. CONCLUSIONS: Bacteria rapidly form biofilm on PPE mesh. Mesh contamination can be catastrophic, and clinicians should consider utilizing an antiseptic solution at the conclusion of mesh implantation. Undiluted povidone-iodine with hydrogen peroxide should be considered when attempting to salvage infected PPE mesh.

Understanding of the residual odour of fatty esters used as emollient in cosmetic products.

OBJECTIVE: Fatty esters are known for their versatility, but in addition to their performance as emollients, emulsifiers, solubilizers, or dispersing agents, they have to meet more and more criteria to be used in cosmetic products. Thus, their olfactory characteristics are expected to be as neutral as possible. However, despite a step of deodorization during the synthesis of fatty esters, a residual odour is currently still perceived at the end of the process. METHODS: In this study, a specific analytical methodology combining sensory with chemical analyses was implemented to characterize the residual odour of two fatty esters and to determine its origin. Ethyl oleate and isononyl isononanoate were selected and underwent a sensory analysis to evaluate their odour intensity and odour profile. Volatile compounds released by these esters were assessed by GC-MS after solid-phase microextraction and among them, odouractive compounds were brought into light using gas chromatography coupled with mass spectrometry and olfactometry analyses. RESULTS: On the isononyl isononanoate chromatogram, only peaks corresponding to the different isomeric ester forms were evidenced while around 70 volatile compounds were detected in the ethyl oleate headspace, including esters, aldehydes, hydrocarbons, and ketones. Isononyl alcohol used as raw material in the synthesis was proven to be responsible for isononyl isononanoate final odour. As for ethyl oleate, of the 23 odour-active compounds perceived, 14 have been identified; they are mainly esters and saturated as well as unsaturated aldehydes. CONCLUSION: A novel measurement approach was presented to analyse trace odours of fatty esters and the results will be useful to control their deodorization by targeting appropriate strategies with the aim to either avoid the formation or remove the identified odorant compounds. This study may be further expanded by investigating the impact of deodorization on odour-active compounds for a complete understanding of their contribution to the fatty ester global odour.

OBJECTIF: Les esters gras sont connus pour leur polyvalence, mais en plus de leurs performances en tant qu'émollients, émulsifiants, solubilisants ou agents dispersants, ils doivent répondre à de plus en plus de critères pour être utilisés dans les produits cosmétiques. Ainsi, une odeur la plus neutre possible est recherchée par les formulateurs. Cependant, malgré une étape de désodorisation lors de la synthèse, une faible odeur résiduelle est souvent encore perçue à la fin du processus. METHODES: Dans cette étude, une méthodologie analytique spécifique combinant des analyses sensorielles et chimiques a été mise en œuvre pour caractériser l'odeur résiduelle de deux esters gras et déterminer son origine. L'oléate d'éthyle et l'isononanoate d'isononyle ont été sélectionnés et une analyse sensorielle a été menée pour évaluer l'intensité et le profil descriptif de leur odeur. Les composés volatils libérés par ces deux esters ont été identifiés par GC-MS après microextraction en phase solide (SPME) et parmi eux, les composés odorants ont été mis en évidence à l'aide de la chromatographie en phase gazeuse couplée à des analyses de spectrométrie de masse et d'olfactométrie (GC-MS-O). RESULTATS: Sur le chromatogramme de l'isononanoate d'isononyle, seuls des pics correspondant aux différentes formes isomériques de l'ester ont été mis en évidence tandis qu'environ 70 composés volatils ont été détectés dans l'espace de tête de l'oléate d'éthyle, parmi lesquels des esters, des aldéhydes, des hydrocarbures et des cétones. Il a été montré que l'alcool isononylique utilisé comme matière première dans la synthèse était responsable de l'odeur finale de l'isononanoate d'isononyle. Pour l'oléate d'éthyle, sur les 23 composés odorants perçus, 14 ont été identifiés ; il s'agit principalement d'esters et d'aldéhydes saturés ou insaturés. CONCLUSION: Ce travail présente une approche efficace pour analyser les traces d'odeur des esters gras. Les résultats obtenus permettront de contrôler la désodorisation de ces ingrédients cosmétiques en ciblant des stratégies appropriées dans le but d'éliminer spécifiquement les composés odorants identifiés. Cette étude pourra être élargie en étudiant l'impact de la désodorisation sur les composés odorants pour une meilleure compréhension de leur contribution à l'odeur globale des esters gras.

Levels of Parental Human Papillomavirus Vaccine Hesitancy and Their Reasons for Not Intending to Vaccinate: Insights From the 2019 National Immunization Survey-Teen.

PURPOSE: A nuanced understanding of human papillomavirus (HPV) vaccine hesitancy is key to tailoring public health interventions to reach HPV vaccination goals in the United States. We aimed to understand the spectrum of parental vaccine hesitancy and identify reasons for lack of vaccination. METHODS: Using cross-sectional data from the 2019 National Immunization Survey-Teen, we examined parents of adolescents aged 13-17 years who had not initiated HPV vaccination. Parents who did not intend to vaccinate their child in the next year were classified into three categories: "unsure," "somewhat hesitant," or "very hesitant." Survey-weighted multinomial logistic regression was used to identify factors associated with level of vaccine hesitancy. RESULTS: Of the 13,090 parents of unvaccinated adolescents, 8,253 (63%) were hesitant. Among those, 63% were very hesitant, 29% were somewhat hesitant, and 8% were unsure. Parents who had received a provider recommendation were less likely to be unsure (adjusted relative risk ratio 0.3, 95% confidence interval 0.2-0.4) or somewhat hesitant (adjusted relative risk ratio 0.8, 95% confidence interval 0.6-0.9). Compared with non-Hispanic White parents, parents of minority race/ethnicity adolescents were more likely to be unsure versus very hesitant. Safety concerns/side effects were the most common reason for lack of intent to vaccinate among very (30%) and somewhat hesitant parents (20%), whereas lack of provider recommendation was the most common reason among unsure parents (34%). DISCUSSION: We identify three distinct levels of HPV vaccine hesitancy and demonstrate that the characteristics and reasons for lack of vaccination differ among these levels. Understanding a parent's level of hesitancy may help maximize the potential impact of public health interventions to reach HPV vaccination goals.

Invasive breast Cancer treatment in Tanzania: landscape assessment to prepare for implementation of standardized treatment guidelines.

BACKGROUND: Incidence of breast cancer continues to rise in low- and middle-income countries, with data from the East African country of Tanzania predicting an 82% increase in breast cancer from 2017 to 2030. We aimed to characterize treatment pathways, receipt of therapies, and identify high-value interventions to increase concordance with international guidelines and avert unnecessary breast cancer deaths. METHODS: Primary data were extracted from medical charts of patients presenting to Bugando Medical Center, Tanzania, with breast concerns and suspected to have breast cancer. Clinicopathologic features were summarized with descriptive statistics. A Poisson model was utilized to estimate prevalence ratios for variables predicted to affect receipt of life-saving adjuvant therapies and completion of therapies. International and Tanzanian guidelines were compared to current care patterns in the domains of lymph node evaluation, metastases evaluation, histopathological diagnosis, and receptor testing to yield concordance scores and suggest future areas of focus. RESULTS: We identified 164 patients treated for suspected breast cancer from April 2015-January 2019. Women were predominantly post-menopausal (43%) and without documented insurance (70%). Those with a confirmed histopathology diagnosis (69%) were 3 times more likely to receive adjuvant therapy (PrR [95% CI]: 3.0 [1.7-5.4]) and those documented to have insurance were 1.8 times more likely to complete adjuvant therapy (1.8 [1.0-3.2]). Out of 164 patients, 4% (n = 7) received concordant care based on the four evaluated management domains. The first most common reason for non-concordance was lack of hormone receptor testing as 91% (n = 144) of cases did not undergo this testing. The next reason was lack of lymph node evaluation (44% without axillary staging) followed by absence of abdominopelvic imaging in those with symptoms (35%) and lack of histopathological confirmation (31%). CONCLUSIONS: Patient-specific clinical data from Tanzania show limitations of current breast cancer management including axillary staging, receipt of formal diagnosis, lack of predictive biomarker testing, and low rates of adjuvant therapy completion. These findings highlight the need to adapt and adopt interventions to increase concordance with guidelines including improving capacity for pathology, developing complete staging pathways, and ensuring completion of prescribed adjuvant therapies.

Architecture-Dependent Mechano-Adaptation in Single Vascular Smooth Muscle Cells.

Arteries grow and remodel following mechanical perturbation. Vascular smooth muscle cells (VSMCs) within the artery undergo hyperplasia, hypertrophy, or change their contractility following sustained changes in loading. Experimental evidence in vivo and in vitro suggests that VSMCs grow and remodel to maintain a constant transmural stress, or "target" stress. This behavior is often described using a stress-dependent finite growth framework. Typically, computational models of arterial growth and remodeling account for VSMC behavior in a constrained mixture formulation that incorporates behavior of each component of the artery. However, these models do not account for differential VSMC architecture observed in situ, which may significantly influence growth and remodeling behavior. Here, we used cellular microbiaxial stretching (CµBS) to characterize how VSMCs with different cytoskeletal architectures respond to a sustained step change in strain. We find that VSMC F-actin architecture becomes more aligned following stretch and retains this alignment after 24 h. Further, we find that VSMC stress magnitude depends on cellular architecture. Qualitatively, however, stress behavior following stretch is consistent across cell architectures-stress increases following stretch and returns to prestretch magnitudes after 24 h. Finally, we formulated an architecture-dependent targeted growth law that accounts for experimentally measured cytoskeletal alignment and attributes stress evolution to individual fiber growth and find that this model robustly captures long-term stress evolution in single VSMCs. These results suggest that VSMC mechano-adaptation depends on cellular architecture, which has implications for growth and remodeling in regions of arteries with differential architecture, such as at bifurcations.

Understanding women's perspectives on breast cancer is essential for cancer control: knowledge, risk awareness, and care-seeking in Mwanza, Tanzania.

BACKGROUND: Breast Cancer is the most common cancer in women worldwide. Since 2008, Mwanza, Tanzania, has worked to provide comprehensive cancer services through its Zonal consultant hospital. New national guidelines focused on clinical breast exam requires that women be aware of and seek care for breast concerns. Therefore, this study aims to understand breast cancer awareness in Mwanza and describe women-level barriers, care-seeking behavior, and perspectives on breast cancer. METHODS: A community-based survey was administered to conveniently sampled women aged 30 and older to assess women's perspectives on breast cancer and care-seeking behavior. RESULTS: Among 1129 women with a median age of 37 (IQR: 31-44) years, 73% have heard of cancer and 10% have received breast health education. Women self-evaluated their knowledge of breast cancer (from 1-none to 10-extremely knowledgeable) with a median response of 3 (IQR: 1-4). Only 14% felt they knew any signs or symptoms of breast cancer. Encouragingly, 56% of women were fairly-to-very confident they would notice changes in their breasts, with 24% of women practicing self-breast examination and 21% reporting they had received a past breast exam. Overall, 74% said they would be somewhat-to-very likely to seek care if they noticed breast changes, with 96% noting severity of symptoms as a motivator. However, fear of losing a breast (40%) and fear of a poor diagnosis (38%) were most frequent barriers to care seeking. In assessing knowledge of risk factors, about 50% of women did not know any risk factors for breast cancer whereas 42% of women believed long term contraceptive use a risk factor. However, 37% and 35% of women did not think that family history or being older were risk factors, respectively. CONCLUSIONS: The success of efforts to improve early diagnosis in a setting without population-based screening depends on women being aware of breast cancer signs and symptoms, risks, and ultimately seeking care for breast concerns. Fortunately, most women said they would seek care if they noticed a change in their breasts, but the low levels of cancer knowledge, symptoms, and common risk factors highlight the need for targeted community education and awareness campaigns.

G1T48, an oral selective estrogen receptor degrader, and the CDK4/6 inhibitor lerociclib inhibit tumor growth in animal models of endocrine-resistant breast cancer.

PURPOSE: The combination of targeting the CDK4/6 and estrogen receptor (ER) signaling pathways with palbociclib and fulvestrant is a proven therapeutic strategy for the treatment of ER-positive breast cancer. However, the poor physicochemical properties of fulvestrant require monthly intramuscular injections to patients, which limit the pharmacokinetic and pharmacodynamic activity of the compound. Therefore, an orally available compound that more rapidly reaches steady state may lead to a better clinical response in patients. Here, we report the identification of G1T48, a novel orally bioavailable, non-steroidal small molecule antagonist of ER. METHODS: The pharmacological effects and the antineoplastic mechanism of action of G1T48 on tumors was evaluated using human breast cancer cells (in vitro) and xenograft efficacy models (in vivo). RESULTS: G1T48 is a potent and efficacious inhibitor of estrogen-mediated transcription and proliferation in ER-positive breast cancer cells, similar to the pure antiestrogen fulvestrant. In addition, G1T48 can effectively suppress ER activity in multiple models of endocrine therapy resistance including those harboring ER mutations and growth factor activation. In vivo, G1T48 has robust antitumor activity in a model of estrogen-dependent breast cancer (MCF7) and significantly inhibited the growth of tamoxifen-resistant (TamR), long-term estrogen-deprived (LTED) and patient-derived xenograft tumors with an increased response being observed with the combination of G1T48 and the CDK4/6 inhibitor lerociclib. CONCLUSIONS: These data show that G1T48 has the potential to be an efficacious oral antineoplastic agent in ER-positive breast cancer.

Salivary cortisol levels by tandem mass spectrometry during high dose ACTH stimulation test for adrenal insufficiency in children.

PURPOSE: Serum cortisol measurements after ACTH stimulation are currently used to evaluate for adrenal insufficiency in children. We aim to determine if salivary cortisol measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) can confirm or replace serum cortisol during high dose ACTH stimulation test to improve test compliance and interpretation. We also aim to gain preliminary understanding of normal ranges of salivary cortisol in normal children at am, bedtime, and midnight. METHODS: Children aged 6-17 years meeting study criteria and tested for adrenal insufficiency were recruited to concomitantly collect saliva and serum samples during high dose ACTH stimulation test. Normal children aged 3-18 years were recruited to collect morning, bedtime, and midnight saliva samples. Salivary cortisol was measured using LC-MS/MS while serum cortisol was determined by an immunoassay. RESULTS: Salivary cortisol in normal children were higher at am and lower at bedtime and midnight (p value <0.0002 and <0.007, respectively). The midnight and bedtime levels were not sufficiently different (p value 0.36). Salivary cortisol during ACTH stimulation test positively and closely correlated with serum cortisol with 100% specificity and sensitivity when 18 µg/dL for serum and 500 ng/dL for salivary cortisol were used as cutoff values respectively for adrenal sufficiency. CONCLUSIONS: Measurement of salivary cortisol by LC-MS/MS is less invasive, more convenient and better time controlled in busy pediatric clinic, therefore is better suited for young children to be used during high dose ACTH stimulation test to evaluate for adrenal insufficiency and to assist interpretation of test results by serum cortisol.

Pharmacokinetic and pharmacodynamic analysis of fulvestrant in preclinical models of breast cancer to assess the importance of its estrogen receptor-α degrader activity in antitumor efficacy.

PURPOSE: Fulvestrant is a selective estrogen receptor downregulator (SERD) that is approved for first- or second-line use as a single agent or in combination with cyclin dependent kinase or phosphatidylinositol 3-kinase inhibitors for the treatment of metastatic breast cancer. Fulvestrant exhibits exceptionally effective antitumor activity in preclinical models of breast cancer, a success that has been attributed to its robust SERD activity despite modest receptor downregulation in patient tumors. By modeling human exposures in animal models we probe the absolute need for SERD activity. METHODS: Three xenograft models of endocrine therapy-resistant breast cancer were used to evaluate the efficacy of fulvestrant administered in doses historically used in preclinical studies in the field or by using a dose regimen intended to model clinical exposure levels. Pharmacokinetic and pharmacodynamic analyses were conducted to evaluate plasma exposure and intratumoral ER downregulation. RESULTS: A clinically relevant 25 mg/kg dose of fulvestrant exhibited antitumor efficacy comparable to the historically used 200 mg/kg dose, but at this lower dose it did not result in robust ER downregulation. Further, the antitumor efficacy of the lower dose of fulvestrant was comparable to that observed for other oral SERDs currently in development. CONCLUSION: The use of clinically unachievable exposure levels of fulvestrant as a benchmark in preclinical development of SERDs may negatively impact the selection of those molecules that are advanced for clinical development. Further, these studies suggest that antagonist efficacy, as opposed to SERD activity, is likely to be the primary driver of clinical response.

Correction to: Pharmacokinetic and pharmacodynamic analysis of fulvestrant in preclinical models of breast cancer to assess the importance of its estrogen receptor-α degrader activity in antitumor efficacy.

The article Pharmacokinetic and pharmacodynamic analysis of fulvestrant in preclinical models of breast cancer to assess the importance of its estrogen receptor-α degrader activity in antitumor efficacy, written by Suzanne E. Wardell, Alexander P. Yllanes, Christina A. Chao, Yeeun Bae, Kaitlyn J. Andreano, Taylor K. Desautels, Kendall A. Heetderks, Jeremy T. Blitzer, John D. Norris, Donald P. McDonnell, was originally published electronically on the publisher's internet portal on September 27, 2019 without open access. With the author(s)' decision to opt for Open Choice the copyright of the article changed on November 16, 2019 to © The Author(s) 2019 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The original article has been corrected.

Pediatric Cancer in Northern Tanzania: Evaluation of Diagnosis, Treatment, and Outcomes.

PURPOSE: The majority of new diagnoses of pediatric cancer are made in resource-poor countries, where survival rates range from 5% to 25% compared with 80% in high-resource countries. Multiple factors, including diagnostic and treatment capacities and complex socioeconomic factors, contribute to this variation. This study evaluated the available resources and outcomes for pediatric patients with cancer at the first oncology treatment center in northern Tanzania. METHODS: Qualitative interviews were completed from July to August 2015 to determine available staff, hospital, diagnostic, treatment, and supportive care resources. A retrospective review of hospital admissions and clinic visits from January 2010 to August 2014 was completed. A total of 298 patients were identified, and data from 182 patient files were included in this review. RESULTS: Diagnostic, treatment, and supportive capacities are limited for pediatric cancer care. The most common diagnoses were Burkitt lymphoma (n = 32), other non-Hodgkin lymphoma (n = 26), and Wilms tumor (n = 25). A total of 40% of patients (n = 72) abandoned care. There was a 20% 2-year event-free survival rate, which was significantly affected by patient age, method of diagnosis, and year of diagnosis. CONCLUSION: To our knowledge, this is the first review of pediatric cancer outcomes in northern Tanzania. The study identified areas for future development to improve pediatric cancer outcomes, which included strengthening of training and diagnostic capacities, development of registries and research databases, and the need for additional research to reduce treatment abandonment.

Dysregulation of mitochondrial dynamics proteins are a targetable feature of human tumors.

Altered mitochondrial dynamics can broadly impact tumor cell physiology. Using genetic and pharmacological profiling of cancer cell lines and human tumors, we here establish that perturbations to the mitochondrial dynamics network also result in specific therapeutic vulnerabilities. In particular, through distinct mechanisms, tumors with increased mitochondrial fragmentation or connectivity are hypersensitive to SMAC mimetics, a class of compounds that induce apoptosis through inhibition of IAPs and for which robust sensitivity biomarkers remain to be identified. Further, because driver oncogenes exert dominant control over mitochondrial dynamics, oncogene-targeted therapies can be used to sensitize tumors to SMAC mimetics via their effects on fission/fusion dynamics. Collectively, these data demonstrate that perturbations to the mitochondrial dynamics network induce targetable vulnerabilities across diverse human tumors and, more broadly, suggest that the altered structures, activities, and trafficking of cellular organelles may facilitate additional cancer therapeutic opportunities.

Clinical utility of an ultrasensitive late night salivary cortisol assay by tandem mass spectrometry.

BACKGROUND: Late night salivary cortisol measurement is a clinically important and convenient screening test for Cushing's syndrome. Tandem mass spectrometry (LC-MS/MS) assays have superior sensitivity and specificity compared to immunoassays. Our goal was to improve a LC-MS/MS method to measure salivary cortisol in both adult and pediatric patients and to characterize its analytical performance by method validation and clinical performance by chart review. METHODS: We improved a LC-MS/MS method originally developed for urine cortisol to measure low level salivary cortisol. The sample preparation was by liquid-liquid extraction using dichloromethane followed by stepwise washing with acidic, basic and neutral solutions. The assay's analytical performance was characterized and retrospective patient chart review was conducted to evaluate the assay's clinical diagnostic performance. RESULTS: The LC-MS/MS assay showed enhanced functional sensitivity of 10 ng/dL for salivary cortisol and was linear within an analytical measurement range of 10-10,000 ng/dL. Assay accuracy was within 84-120% as determined by recovery studies and correlation with a reference method. Data from healthy adult volunteers was compiled to establish the reference interval for late night salivary cortisol. Patient chart review determined subjects with diagnosis of Cushing's syndrome or disease, and assay's clinical diagnostic sensitivity of 100% and specificity of 92% when the cutoff value was 70 ng/dL. CONCLUSIONS: The improved LC-MS/MS method is sensitive and specific with enhanced analytical performance and clinical diagnostic utility for screening Cushing's syndrome. The assay may have broad clinical application due to its high sensitivity and wide dynamic range.

Inhibiting androgen receptor nuclear entry in castration-resistant prostate cancer.

Clinical resistance to the second-generation antiandrogen enzalutamide in castration-resistant prostate cancer (CRPC), despite persistent androgen receptor (AR) activity in tumors, highlights an unmet medical need for next-generation antagonists. We have identified and characterized tetra-aryl cyclobutanes (CBs) as a new class of competitive AR antagonists that exhibit a unique mechanism of action. These CBs are structurally distinct from current antiandrogens (hydroxyflutamide, bicalutamide, and enzalutamide) and inhibit AR-mediated gene expression, cell proliferation, and tumor growth in several models of CRPC. Conformational profiling revealed that CBs stabilize an AR conformation resembling an unliganded receptor. Using a variety of techniques, it was determined that the AR-CB complex was not recruited to AR-regulated promoters and, like apo AR, remains sequestered in the cytoplasm, bound to heat shock proteins. Thus, we have identified third-generation AR antagonists whose unique mechanism of action suggests that they may have therapeutic potential in CRPC.

Evaluation of the pharmacological activities of RAD1901, a selective estrogen receptor degrader.

Endocrine therapy, using tamoxifen or an aromatase inhibitor, remains a first-line treatment for estrogen receptor 1 (ESR1) positive breast cancer. However, tumor resistance limits the duration of response. The clinical efficacy of fulvestrant, a selective ER degrader (SERD) that triggers receptor degradation, has confirmed that ESR1 often remains engaged in endocrine therapy resistant cancers. Recently developed, selective ER modulators (SERMs)/SERD hybrids (SSHs) that facilitate ESR1 degradation in breast cancer cells and reproductive tissues have been advanced as an alternative treatment for advanced breast cancer, particularly in the metastatic setting. RAD1901 is one SSH currently being evaluated clinically that is unique among ESR1 modulators in that it readily enters the brain, a common site of breast cancer metastasis. In this study, RAD1901 inhibited estrogen activation of ESR1 in vitro and in vivo, inhibited estrogen-dependent breast cancer cell proliferation and xenograft tumor growth, and mediated dose-dependent downregulation of ESR1 protein. However, doses of RAD1901 insufficient to induce ESR1 degradation were shown to result in the activation of ESR1 target genes and in the stimulation of xenograft tumor growth. RAD1901 is an SSH that exhibits complex pharmacology in breast cancer models, having dose-dependent agonist/antagonist activity displayed in a tissue-selective manner. It remains unclear how this unique pharmacology will impact the utility of RAD1901 for breast cancer treatment. However, being the only SERD currently known to access the brain, RAD1901 merits evaluation as a targeted therapy for the treatment of breast cancer brain metastases.

Novel GATA6 mutations in patients with pancreatic agenesis and congenital heart malformations.

Patients with pancreatic agenesis are born without a pancreas, causing permanent neonatal diabetes and pancreatic enzyme insufficiency. These patients require insulin and enzyme replacement therapy to survive, grow, and maintain normal blood glucose levels. Pancreatic agenesis is an uncommon condition but high-throughput sequencing methods provide a rare opportunity to identify critical genes that are necessary for human pancreas development. Here we present the clinical history, evaluation, and the genetic and molecular analysis from two patients with pancreatic agenesis. Both patients were born with intrauterine growth restriction, minor heart defects and neonatal diabetes. In both cases, pancreatic agenesis was confirmed by imaging studies. The patients are clinically stable with pancreatic enzymes and insulin therapy. In order identify the etiology for their disease, we performed whole exome sequencing on both patients. For each proband we identified a de novo heterozygous mutation in the GATA6 gene. GATA6 is a homeobox containing transcription factor involved in both early development of the pancreas and heart. In vitro functional analysis of one of the variants revealed that the mutation creates a premature stop codon in the coding sequence resulting in the production of a truncated protein with loss of activity. These results show how genetic mutations in GATA6 may lead to functional inactivity and pancreatic agenesis in humans.

Bazedoxifene exhibits antiestrogenic activity in animal models of tamoxifen-resistant breast cancer: implications for treatment of advanced disease.

PURPOSE: There is compelling evidence to suggest that drugs that function as pure estrogen receptor (ER-α) antagonists, or that downregulate the expression of ER-α, would have clinical use in the treatment of advanced tamoxifen- and aromatase-resistant breast cancer. Although such compounds are currently in development, we reasoned, based on our understanding of ER-α pharmacology, that there may already exist among the most recently developed selective estrogen receptor modulators (SERM) compounds that would have usage as breast cancer therapeutics. Thus, our objective was to identify among available SERMs those with unique pharmacologic activities and to evaluate their potential clinical use with predictive models of advanced breast cancer. EXPERIMENTAL DESIGN: A validated molecular profiling technology was used to classify clinically relevant SERMs based on their impact on ER-α conformation. The functional consequences of these observed mechanistic differences on (i) gene expression, (ii) receptor stability, and (iii) activity in cellular and animal models of advanced endocrine-resistant breast cancer were assessed. RESULTS: The high-affinity SERM bazedoxifene was shown to function as a pure ER-α antagonist in cellular models of breast cancer and effectively inhibited the growth of both tamoxifen-sensitive and -resistant breast tumor xenografts. Interestingly, bazedoxifene induced a unique conformational change in ER-α that resulted in its proteasomal degradation, although the latter activity was dispensable for its antagonist efficacy. CONCLUSION: Bazedoxifene was recently approved for use in the European Union for the treatment of osteoporosis and thus may represent a near-term therapeutic option for patients with advanced breast cancer.

High prevalence of hearing impairment in HIV-infected Peruvian children.

OBJECTIVES: To measure the prevalence and to identify risk factors of hearing impairment in human immunodeficiency virus-infected children living in Peru. STUDY DESIGN: Cross-sectional observational study. SETTING: Two public hospitals and 1 nonprofit center in Lima, Peru, between August 2009 and April 2010. SUBJECTS: A total of 139 HIV-infected children, ages 4 to 19 years. METHODS: Hearing impairment and otologic health were assessed with pure tone audiometry, tympanometry, and otoscopy. The primary outcome was hearing loss, defined as average threshold >25dB for 0.5, 1, 2, and 4 kHz, in one or both ears. Historical and socioeconomic information was obtained through parental survey and medical chart review. Statistical analysis included univariate analysis and multivariate logistic regression. RESULTS: Fifty-four (38.8%) of 139 children had hearing impairment. On multivariate analysis, risk factors included: tympanic membrane perforation (odds ratio [OR] 7.08; 95% confidence interval [CI], 1.65-30.5; P = .01), abnormal tympanometry (OR 2.71; 95% CI, 1.09-6.75; P = .03), cerebral infection (OR 11.6; 95% CI, 1.06-126; P = .05), seizures (OR 5.20; 95% CI, 1.21-22.4; P = .03), and CD4 cell count <500 cells/mm(3) (OR 3.53; 95% CI, 1.18-10.5; P = .02). CONCLUSIONS: The prevalence of hearing impairment in HIV-infected children in Lima, Peru was 38.8%. Middle ear disease, prior cerebral infection, and low CD4 cell count were significantly associated with hearing impairment. The high prevalence of hearing impairment emphasizes the need for periodic hearing assessment in the routine clinical care of HIV-infected children.