Systematic literature review of real-world evidence for treatments in HR+/HER2- second-line LABC/mBC after first-line treatment with CDK4/6i.

BACKGROUND: Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) combined with endocrine therapy (ET) are currently recommended by the National Comprehensive Cancer Network (NCCN) guidelines and the European Society for Medical Oncology (ESMO) guidelines as the first-line (1 L) treatment for patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, locally advanced/metastatic breast cancer (HR+/HER2- LABC/mBC). Although there are many treatment options, there is no clear standard of care for patients following 1 L CDK4/6i. Understanding the real-world effectiveness of subsequent therapies may help to identify an unmet need in this patient population. This systematic literature review qualitatively synthesized effectiveness and safety outcomes for treatments received in the real-world setting after 1 L CDK4/6i therapy in patients with HR+/ HER2- LABC/mBC. METHODS: MEDLINE®, Embase, and Cochrane were searched using the Ovid® platform for real-world evidence studies published between 2015 and 2022. Grey literature was searched to identify relevant conference abstracts published from 2019 to 2022. The review was conducted in accordance with PRISMA guidelines (PROSPERO registration: CRD42023383914). Data were qualitatively synthesized and weighted average median real-world progression-free survival (rwPFS) was calculated for NCCN/ESMO-recommended post-1 L CDK4/6i treatment regimens. RESULTS: Twenty records (9 full-text articles and 11 conference abstracts) encompassing 18 unique studies met the eligibility criteria and reported outcomes for second-line (2 L) treatments after 1 L CDK4/6i; no studies reported disaggregated outcomes in the third-line setting or beyond. Sixteen studies included NCCN/ESMO guideline-recommended treatments with the majority evaluating endocrine-based therapy; five studies on single-agent ET, six studies on mammalian target of rapamycin inhibitors (mTORi) ± ET, and three studies with a mix of ET and/or mTORi. Chemotherapy outcomes were reported in 11 studies. The most assessed outcome was median rwPFS; the weighted average median rwPFS was calculated as 3.9 months (3.3-6.0 months) for single-agent ET, 3.6 months (2.5-4.9 months) for mTORi ± ET, 3.7 months for a mix of ET and/or mTORi (3.0-4.0 months), and 6.1 months (3.7-9.7 months) for chemotherapy. Very few studies reported other effectiveness outcomes and only two studies reported safety outcomes. Most studies had heterogeneity in patient- and disease-related characteristics. CONCLUSIONS: The real-world effectiveness of current 2 L treatments post-1 L CDK4/6i are suboptimal, highlighting an unmet need for this patient population.

Phase Ib/II Study of the Efficacy and Safety of Binimetinib (MEK162) Plus Panitumumab for Mutant or Wild-Type RAS Metastatic Colorectal Cancer.

INTRODUCTION: Activating RAS gene mutations occur in approximately 55% of patients with metastatic colorectal cancer (mCRC) and are associated with poorer clinical outcomes due to epidermal growth factor receptor (EGFR) blockade resistance. Combined EGFR and mitogen-activated protein kinase (MEK) inhibition may extend response to EGFR inhibition and overcome acquired resistance. This phase Ib/II dose escalation trial evaluated the safety and activity of dual inhibition with binimetinib (MEK1/2 inhibitor) and panitumumab (EGFR inhibitor [EGFRi]) in patients with RAS mutant or BRAF wild type (WT)/RAS WT mCRC. METHODS: Phase Ib dose escalation started with binimetinib 45 mg twice daily plus panitumumab 6 mg/kg administered every 2 weeks. In the phase II study, patients with measurable mCRC were enrolled into 4 groups based on previous anti-EGFR monoclonal antibody therapy and RAS mutational status. RESULTS: No patients in the phase Ib portion (n = 10) had a response; 70% of patients had stable disease. In the phase II portion (n = 43), overall response rate (ORR, confirmed) was 2.3% with one partial response in the RAS WT group, DCR was 30.2%, and median progression-free survival was 1.8 months (95%CI, 1.6-3.3). All patients experienced ≥1 adverse event, with the most common being diarrhea (71.7%), vomiting (52.8%), nausea (50.9%), fatigue (49.1%), dermatitis acneiform (43.4%), and rash (41.5%). Most patients required treatment interruption or dose reduction due to difficulties tolerating treatment. CONCLUSIONS: The combination of binimetinib and panitumumab had substantial toxicity and limited clinical activity for patients with mutant or WT RAS mCRC, independent of EGFRi treatment history (Trial registration: NCT01927341).

Understanding how shared decision-making approaches and patient aids influence patients with advanced cancer when deciding on palliative treatments and care: A realist review.

BACKGROUND: Patients with advanced incurable cancer face difficult decisions about palliative treatment options towards their end of life. However, they are often not provided with the appropriate information and support that is needed to make informed decisions. This review aimed to identify contexts and mechanisms associated with communication tools, patient decision-aids and shared decision-making (SDM) approaches that influence patient outcomes. METHODS: We used a realist review method to search for published studies of patients (adults > 18) with advanced cancer who were expected to make a decision about palliative treatment and/or supportive care in consultation with healthcare practitioners. We appraised and synthesised literature describing the contexts of (when and how) decision aids and SDM approaches are used, and how these contexts interact with mechanisms (resources and reasoning) which impact patient outcomes. Stakeholders including academics, palliative healthcare professionals (HCPs) and people with lived experience of supporting people with advanced incurable cancer contributed to identifying explanatory accounts. These accounts were documented, analysed and consolidated to contribute to the development of a programme theory. RESULTS: From the 33 included papers, we consolidated findings into 20 explanatory accounts to develop a programme theory that explains key contexts and mechanisms that influence patient and SDM. Contexts include underlying patients' and HCPs' attitudes and approaches. These need to be understood in relation to key mechanisms, including presenting information in multiple formats and providing adequate time and opportunities to prepare for and revisit decisions. Contexts influenced mechanisms which then influence the levels of patient decisional satisfaction, conflict and regret. CONCLUSIONS: Our programme theory highlights mechanisms that are important in supporting shared treatment decisions for advanced noncurative cancer. The findings are informative for developing and evaluating interventions to improve understanding and involvement in SDM for patients with advanced incurable cancer. PATIENT AND PUBLIC CONTRIBUTION: We included patient and public involvement (PPI) representatives in four stakeholder meetings. PPI helped to define the scope of the review, identify their unique experiences and perspectives, synthesise their perspectives with our review findings, make decisions about which theories we included in our programme theory and develop recommendations for policy and practice and future research.

COLUMBUS 5-year update: a randomized, open-label, phase III trial of encorafenib plus binimetinib versus vemurafenib or encorafenib in patients with BRAF.

WHAT IS THIS SUMMARY ABOUT?: Here, we summarize the 5-year results from part 1 of the COLUMBUS clinical study, which looked at the combination treatment of encorafenib plus binimetinib in people with a specific type of skin cancer called melanoma. Encorafenib (BRAFTOVI®) and binimetinib (MEKTOVI®) are medicines used to treat a type of melanoma that has a change in the BRAF gene, called advanced or metastatic BRAF V600-mutant melanoma. Participants with advanced or metastatic BRAF V600-mutant melanoma took either encorafenib plus binimetinib together (COMBO group), compared with encorafenib alone (ENCO group) or vemurafenib (ZELBORAF®) alone (VEMU group). WHAT WERE THE RESULTS?: In this 5-year update, more participants in the COMBO group were alive for longer without their disease getting worse after 5 years than those in the VEMU and ENCO groups. Patients in the COMBO group were alive for longer without their disease getting worse when they: Had less advanced cancer Were able to do more daily activities Had normal lactate dehydrogenase (LDH) levels Had fewer organs with tumors before treatment After treatment, fewer participants in the COMBO group received additional anticancer treatment than participants in the VEMU and ENCO groups. The number of participants who reported severe side effects was similar for each treatment. The side effects caused by the drugs in the COMBO group decreased over time. WHAT DO THE RESULTS MEAN?: Overall, this 5-year update confirmed that people with BRAF V600-mutant melanoma that has spread to other parts of the body and who took encorafenib plus binimetinib were alive for longer without their disease getting worse than those who took vemurafenib or encorafenib alone. Clinical Trial Registration: NCT01909453 (ClinicalTrials.gov).

A Phase Ib/II Study of WNT974 + Encorafenib + Cetuximab in Patients With BRAF V600E-Mutant KRAS Wild-Type Metastatic Colorectal Cancer.

BACKGROUND: WNT974 is a small molecule inhibitor of Wnt signaling that specifically inhibits porcupine O-acyltransferase. This phase Ib dose--escalation study evaluated the maximum tolerated dose of WNT974 in combination with encorafenib and cetuximab in patients with BRAF V600E-mutant metastatic colorectal cancer with RNF43 mutations or RSPO fusions. PATIENTS AND METHODS: Patients received once-daily encorafenib and weekly cetuximab, in addition to once-daily WNT974, in sequential dosing cohorts. In the first cohort, patients received 10-mg WNT974 (COMBO10), which was reduced in subsequent cohorts to 7.5-mg (COMBO7.5) or 5-mg (COMBO5) after dose-limiting toxicities (DLTs) were observed. Primary endpoints were incidence of DLTs and exposure to WNT974 and encorafenib. Secondary endpoints were anti-tumor activity and safety. RESULTS: Twenty patients were enrolled (COMBO10, n = 4; COMBO7.5, n = 6; COMBO5, n = 10). DLTs were observed in 4 patients, including grade 3 hypercalcemia (COMBO10, n = 1; COMBO7.5, n = 1), grade 2 dysgeusia (COMBO10, n = 1), and lipase increased (COMBO10, n = 1). A high incidence of bone toxicities (n = 9) was reported, including rib fracture, spinal compression fracture, pathological fracture, foot fracture, hip fracture, and lumbar vertebral fracture. Serious adverse events were reported in 15 patients, most frequently bone fracture, hypercalcemia, and pleural effusion. The overall response rate was 10% and disease control rate 85%; most patients achieved stable disease as their best response. CONCLUSION: Concerns surrounding the safety and lack of preliminary evidence of improved anti-tumor activity of WNT974 + encorafenib + cetuximab, compared with previous encorafenib + cetuximab data, ultimately led to study discontinuation. Phase II was not initiated. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02278133.

COLUMBUS 5-Year Update: A Randomized, Open-Label, Phase III Trial of Encorafenib Plus Binimetinib Versus Vemurafenib or Encorafenib in Patients With BRAF V600-Mutant Melanoma.

PURPOSE: Combination treatment with BRAF and MEK inhibitors has demonstrated benefits on progression-free survival (PFS) and overall survival (OS) and is a standard of care for the treatment of advanced BRAF V600-mutant melanoma. Here, we report the 5-year update from the COLUMBUS trial (ClinicalTrials.gov identifier: NCT01909453). METHODS: Patients with locally advanced unresectable or metastatic BRAF V600-mutant melanoma, untreated or progressed after first-line immunotherapy, were randomly assigned 1:1:1 to encorafenib 450 mg once daily plus binimetinib 45 mg twice daily, vemurafenib 960 mg twice daily, or encorafenib 300 mg once daily. An updated analysis was conducted 65 months after the last patient was randomly assigned. RESULTS: Five hundred seventy-seven patients were randomly assigned: 192 to encorafenib plus binimetinib, 191 to vemurafenib, and 194 to encorafenib. The 5-year PFS and OS rates with encorafenib plus binimetinib were 23% and 35% overall and 31% and 45% in those with normal lactate dehydrogenase levels, respectively. In comparison, the 5-year PFS and OS rates with vemurafenib were 10% and 21% overall and 12% and 28% in those with normal lactate dehydrogenase levels, respectively. The median duration of response with encorafenib plus binimetinib was 18.6 months, with disease control achieved in 92.2% of patients. In comparison, the median duration of response with vemurafenib was 12.3 months, with disease control achieved in 81.2% of patients. Long-term follow-up showed no new safety concerns, and results were consistent with the known tolerability profile of encorafenib plus binimetinib. Interactive visualization of the data presented in this article is available at COLUMBUS dashboard. CONCLUSION: In this 5-year update of part 1 of the COLUMBUS trial, encorafenib plus binimetinib treatment demonstrated continued long-term benefits and a consistent safety profile in patients with BRAF V600-mutant melanoma.

Effect of lipopolysaccharide-induced immune stimulation and maternal fish oil and microalgae supplementation during late pregnancy on nursery pig hypothalamic-pituitary-adrenal function1.

The present study used Escherichia coli lipopolysaccharide (LPS) to investigate whether maternal immune challenge during late gestation altered programming of the offspring hypothalamus and hypothalamic-pituitary-adrenal axis (HPAA). In addition, interactions of maternal diet, supplementation with fish oil (FO) or microalgae (AL), and complex vs. simple weaning diets were investigated. Briefly, Landrace × Yorkshire sows (N = 48) were randomly assigned to diets supplemented with FO, AL, or a standard gestation control diet (CON) from day 75 of gestation (gd 75) until parturition. On gd 112, half the sows from each dietary treatment were immune challenged with LPS (10 µg/kg BW) or saline as a control. At 21 d postpartum, the offspring were weaned, and half the animals from each maternal treatment were allocated to either a complex or simple weaning diet. At 28 d postpartum, the offspring's hourly fever and 2-h cortisol responses to LPS immune challenge (40 µg/kg BW) were measured to assess hypothalamus and HPAA function. Results indicated that the maternal temperature of sows on the FO diet returned to baseline levels faster than sows on the AL and CON diets after LPS immune challenge (P < 0.05). In contrast, there was no difference in the maternal cortisol response across the dietary treatments (P > 0.10). Regardless of the dietary treatments, the maternal LPS immune challenge induced a greater cortisol response in male offspring (P = 0.05) and a greater fever response in female offspring (P = 0.03) when they were LPS immune challenged post-weaning. Male offspring from LPS-immune-challenged sows fed the FO and AL diets had a greater fever response than male offspring from the maternal CON diet group (P ≤ 0.05). Last, no effect of the complex or simple weaning diets was observed for the nursery pig cortisol or fever responses to LPS immune challenge. In conclusion, LPS immune challenge during late pregnancy altered responsiveness of the offspring hypothalamus and HPAA to this same microbial stressor, and a sex-specific response was influenced by maternal dietary supplementation with FO and AL.

Considerations and recommendations for conducting qualitative research interviews with palliative and end-of-life care patients in the home setting: a consensus paper.

OBJECTIVES: To present and discuss the views of researchers at an academic palliative care research centre on research encounters with terminally ill patients in the home setting and to generate a list of recommendations for qualitative researchers working in palliative and end-of-life care. METHODS: Eight researchers took part in a consensus meeting to discuss their experiences of undertaking qualitative interviews. The researchers were of varying backgrounds and all reported having experience in interviewing terminally ill patients, and all but one had experience of interviewing patients in their home environment. RESULTS: The main areas discussed by researchers included: whether participation in end-of-life research unintentionally becomes a therapeutic experience or an ethical concern; power relationships between terminally ill patients and researchers; researcher reflexivity and reciprocity; researchers' training needs. Qualitative methods can complement the home environment; however, it can raise ethical and practical challenges, which can be more acute in the case of research undertaken with palliative and patients at the end-of-life. CONCLUSIONS: The ethical and practical challenges researchers face in this context has the potential to place both participant and researcher at risk for their physical and psychological well-being. We present a set of recommendations for researchers to consider prior to embarking on qualitative research in this context and advocate researchers in this field carefully consider the issues presented on a study-by-study basis.

Managing, making sense of and finding meaning in advanced illness: a qualitative exploration of the coping and wellbeing experiences of patients with lung cancer.

Coping plays an essential role in maintaining the wellbeing of patients with cancer. A number of different coping responses and strategies have been identified in the literature. The value and relevance of meaning based coping theory has also been emphasised, including Antonovosky's Sense of Coherence (SoC) theory. Ten patients with advanced lung cancer were interviewed up to three times. A total of twenty in depth interviews were carried out, fully transcribed and data were analysed following a methodology of Interpretative Phenomenological Analysis. Three broad domains were identified to categorise the core life concerns of participants; making sense of and managing one's illness; maintaining daily life and relationships and confronting the future. Within these domains multiple coping themes are identified, which to varying degrees help to maintain patient wellbeing and quality of life. This article considers the relevance of SoC theory for understanding the coping experiences of patients with advanced cancer, and identifies resources and factors likely to support patient coping, with implications for health and social care services.

"I didn't really understand it, I just thought it'd help": exploring the motivations, understandings and experiences of patients with advanced lung cancer participating in a non-placebo clinical IMP trial.

BACKGROUND: Few studies have explored in depth the experiences of patients with advanced cancer who are participating in clinical investigational medicinal product trials. However, integrated qualitative studies in such trials are needed to enable a broader evaluation of patient experiences in the trial, with important ethical and practical implications for the design and conduct of similar trials and treatment regimes in the future. METHODS: Ten participants were recruited from the control and intervention arms of FRAGMATIC: a non-placebo trial for patients with advanced lung cancer. Participants were interviewed at up to three time points during their time in the trial. Interviews were analysed using Interpretive Phenomenological Analysis. RESULTS: Patients were motivated to join the trial out of hope of medical benefit and altruism. Understanding of randomisation was mixed and in some cases poor, as was appreciation of trial purpose and equipoise. The trial was acceptable to and evaluated positively by most participants; participants receiving the intervention focused on the potential treatment benefits they hoped they would receive, whilst participants in the control arm found alternative reasons, such as altruism, personal fulfilment and positive attention, to commit to and perceive benefits from the trial. However, whilst experiences were generally very positive, poor understanding, limited engagement with trial information and focus on treatment benefits amongst some participants give cause for concern. CONCLUSIONS: By exploring longitudinally the psychological, emotional and cognitive domains of trial participation, we consider potential harms and benefits of participation in non-placebo trials amongst patients with advanced lung cancer and identify several implications for future research with and care for patients with advanced cancer. TRIAL REGISTRATION: ISRCTN80812769 . Registered on 8 July 2005.

The Q510E mutation in Shp2 perturbs heart valve development by increasing cell migration.

Tightly regulated cellular signaling is critical for correct heart valve development, but how and why signaling is dysregulated in congenital heart disease is not very well known. We focused on protein tyrosine phosphatase Shp2, because mutations in this signaling modulator frequently cause valve malformations associated with Noonan syndrome or Noonan syndrome with multiple lentigines (NSML). To model NSML-associated valve disease, we targeted overexpression of Q510E-Shp2 to mouse endocardial cushions (ECs) using a Tie2-Cre-based approach. At midgestation, Q510E-Shp2 expression increased the size of atrioventricular ECs by 80%. To dissect the underlying cellular mechanisms, we explanted ECs from chick embryonic hearts and induced Q510E-Shp2 expression using adenoviral vectors. Valve cell outgrowth from cultured EC explants into surrounding matrix was significantly increased by Q510E-Shp2 expression. Because focal adhesion kinase (FAK) is a critical regulator of cell migration, we tested whether FAK inhibition counteracts the Q510E-Shp2-induced effects in explanted ECs. The FAK/src inhibitor PP2 normalized valve cell outgrowth from Q510E-Shp2-expressing ECs. Next, chick ECs were further dissociated to assess cell proliferation and migration. Valve cell proliferation was not increased by Q510E-Shp2 as determined by label incorporation. In contrast, valve cell migration as reflected in a wound-healing assay was increased by Q510E-Shp2 expression, indicating that increased migration is the predominant effect of Q510E-Shp2 expression in ECs. In conclusion, PP2-sensitive signaling mediates the pathogenic effects of Q510E-Shp2 on cell migration in EC explant cultures. This suggests a central role for FAK and provides new mechanistic insight into the molecular basis of valve defects in NSML.

New approaches to prevent LEOPARD syndrome-associated cardiac hypertrophy by specifically targeting Shp2-dependent signaling.

In LEOPARD syndrome (LS) patients, mutations in the protein tyrosine phosphatase Shp2 cause hypertrophic cardiomyopathy. The prohypertrophic effects of mutant Shp2 are mediated downstream by hyperactivation of mammalian target of rapamycin. Our goal was to further define the signaling cascade that is essential for the underlying pathomechanism, thus expanding the list of potential future therapeutic targets. Using cultured neonatal rat cardiomyocytes with adenoviral gene delivery and pharmacological inhibitors, we found that hypertrophy induced by a particularly aggressive LS mutation in Shp2 depends on hyperactivation of Akt and focal adhesion kinase as well as mammalian target of rapamycin. Dissecting domain-specific functions of Shp2 using double and truncation mutants, we determined that the hypertrophic effects of mutant Shp2 depend on the two SH2 domains and on an intact catalytic center. The latter finding prompted us to test the efficacy of a Shp2 inhibitor targeted directly at the catalytic pocket. This compound, PHPS1, effectively prevented mutant Shp2-induced hypertrophy. In summary, we identified three novel targets for pharmacological therapy of LS-associated cardiac hypertrophy. Of particular importance is the finding that intervention directly at the mutant Shp2 protein is effective because this would facilitate custom-tailored therapeutic approaches for patients carrying LS mutations in Shp2.

Gestational exposure to bisphenol a produces transgenerational changes in behaviors and gene expression.

Bisphenol A (BPA) is a plasticizer and an endocrine-disrupting chemical. It is present in a variety of products used daily including food containers, paper, and dental sealants and is now widely detected in human urine and blood. Exposure to BPA during development may affect brain organization and behavior, perhaps as a consequence of its actions as a steroid hormone agonist/antagonist and/or an epigenetic modifier. Here we show that BPA produces transgenerational alterations in genes and behavior. Female mice received phytoestrogen-free chow with or without BPA before mating and throughout gestation. Plasma levels of BPA in supplemented dams were in a range similar to those measured in humans. Juveniles in the first generation exposed to BPA in utero displayed fewer social interactions as compared with control mice, whereas in later generations (F(2) and F(4)), the effect of BPA was to increase these social interactions. Brains from embryos (embryonic d 18.5) exposed to BPA had lower gene transcript levels for several estrogen receptors, oxytocin, and vasopressin as compared with controls; decreased vasopressin mRNA persisted into the F(4) generation, at which time oxytocin was also reduced but only in males. Thus, exposure to a low dose of BPA, only during gestation, has immediate and long-lasting, transgenerational effects on mRNA in brain and social behaviors. Heritable effects of an endocrine-disrupting chemical have implications for complex neurological diseases and highlight the importance of considering gene-environment interactions in the etiology of complex disease.

The PTPN11 loss-of-function mutation Q510E-Shp2 causes hypertrophic cardiomyopathy by dysregulating mTOR signaling.

The identification of mutations in PTPN11 (encoding the protein tyrosine phosphatase Shp2) in families with congenital heart disease has facilitated mechanistic studies of various cardiovascular defects. However, the roles of normal and mutant Shp2 in the developing heart are still poorly understood. Furthermore, it remains unclear how Shp2 loss-of-function (LOF) mutations cause LEOPARD Syndrome (also termed Noonan Syndrome with multiple lentigines), which is characterized by congenital heart defects such as pulmonary valve stenosis and hypertrophic cardiomyopathy (HCM). In normal hearts, Shp2 controls cardiomyocyte size by regulating signaling through protein kinase B (Akt) and mammalian target of rapamycin (mTOR). We hypothesized that Shp2 LOF mutations dysregulate this pathway, resulting in HCM. For our studies, we chose the Shp2 mutation Q510E, a dominant-negative LOF mutation associated with severe early onset HCM. Newborn mice with cardiomyocyte-specific overexpression of Q510E-Shp2 starting before birth displayed increased cardiomyocyte sizes, heart-to-body weight ratios, interventricular septum thickness, and cardiomyocyte disarray. In 3-mo-old hearts, interstitial fibrosis was detected. Echocardiographically, ventricular walls were thickened and contractile function was depressed. In ventricular tissue samples, signaling through Akt/mTOR was hyperactivated, indicating that the presence of Q510E-Shp2 led to upregulation of this pathway. Importantly, rapamycin treatment started shortly after birth rescued the Q510E-Shp2-induced phenotype in vivo. If rapamycin was started at 6 wk of age, HCM was also ameliorated. We also generated a second mouse model in which cardiomyocyte-specific Q510E-Shp2 overexpression started after birth. In contrast to the first model, these mice did not develop HCM. In summary, our studies establish a role for mTOR signaling in HCM caused by Q510E-Shp2. Q510E-Shp2 overexpression in the cardiomyocyte population alone was sufficient to induce the phenotype. Furthermore, the pathomechanism was triggered pre- but not postnatally. However, postnatal rapamycin treatment could still reverse already established HCM, which may have important therapeutic implications.

Gestational exposure to low dose bisphenol A alters social behavior in juvenile mice.

Bisphenol A (BPA) is a man-made compound used to make polycarbonate plastics and epoxy resins; public health concerns have been fueled by findings that BPA exposure can reduce sex differences in brain and some behaviors. We asked if a low BPA dose, within the range measured in humans, ingested during pregnancy, would affect social behaviors in prepubertal mice. We noted sex differences in social interactions whereby females spent more time sitting side-by-side, while males engaged in more exploring and sitting alone. In addition BPA increased display of nose-to-nose contacts, play solicitations and approaches in both sexes. Interactions between sex and diet were found for self grooming, social interactions while sitting side-by-side and following the other mouse. In all these cases interactions were produced by differences between control and BPA females. We examined brains from embryos during late gestation to determine if gene expression differences might be correlated with some of the sexually dimorphic or BPA affected behaviors we observed. Because BPA treatments ended at birth we took the brains during embryogenesis to increase the probability of discovering BPA mediated effects. We also selected this embryonic age (E18.5) because it coincides with the onset of sexual differentiation of the brain. Interestingly, mRNA for the glutamate transporter, Slc1a1, was enhanced by exposure to BPA in female brains. Also we noted that BPA changed the expression of two of the three DNA methyltransferase genes, Dnmt1 and Dnmt3a. We propose that BPA affects DNA methylation of Sc1a1 during neural development. Sex differences in juvenile social interactions are affected by BPA and in particular this compound modifies behavior in females.

1993 2003 gender differences in coronary artery revascularization: has anything changed?

BACKGROUND: Gender differences abound in patients undergoing coronary artery bypass graft (CABG) surgery. Most research was conducted in the early 1 990s. It is unknown if gender differences have diminished over time. RESEARCH OBJECTIVES: To determine whether gender differences exist in the current era of CABG surgery by examining preoperative, intraoperative, and postoperative factors known to affect outcomes. SUBJECTS AND METHODS: In this descriptive, correlational study of all patients undergoing primary, isolated CABG at a large, urban Midwestern healthcare center, data in 1993 and 2003 were analyzed to determine if gender and time differences existed and if there was a time and gender interaction effect. Trained nurses prospectively collected data during the index hospitalization for the institution's Cardiovascular Information Registry. RESULTS: 2,200 patients were studied; women accounted for one-fourth of the sample. Age over 65 years; current smoking; presence of hypertension, cerebrovascular accident; and insulin-dependent diabetes; symptomatic heart failure and chest pain were significantly associated with female gender (all P' s < .001). Intraoperatively, internal mammary arteries were used less as a graft conduit in women (P < .001); gender differences were most pronounced in patients requiring 2 bypass grafts. Postoperatively, cardiac pump failure and median hospital stay were greater in women (both P' s < .001); however, both decreased over time. CONCLUSIONS: Gender differences continue to exist in patients undergoing CABG. Differences do not affect hospital mortality rates but play a role in hospital length of stay and may affect postdischarge recovery. Research targeted at modifiable preoperative factors may improve postoperative recovery.

The closed structure of the MscS mechanosensitive channel. Cross-linking of single cysteine mutants.

Mechanosensitive channels must make a large conformational change during the transition from the closed to the open state. The crystal structure of the open form of the Escherichia coli MscS channel was recently solved and depicts a homoheptamer (1). In this study, cross-linking of site-specific cysteine substitutions demonstrates that residues up to 10-33 A apart in the crystal structure readily form disulfide bridges in the closed form and can also be cross-linked by a 10-A linker. Cross-linking between adjacent subunits stabilizes the heptameric form of the channel providing biochemical evidence to support the crystal structure. The data are consistent with the published model (1) in that the membrane domain is highly flexible and that the closed to open transition may involve a significant displacement of transmembrane helices 1 and 2, possibly by as much as 30 A. The data are also consistent with significant flexibility of the cytoplasmic domain.