Identification of MALT1 feedback mechanisms enables rational design of potent antilymphoma regimens for ABC-DLBCL.

MALT1 inhibitors are promising therapeutic agents for B-cell lymphomas that are dependent on constitutive or aberrant signaling pathways. However, a potential limitation for signal transduction-targeted therapies is the occurrence of feedback mechanisms that enable escape from the full impact of such drugs. Here, we used a functional genomics screen in activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL) cells treated with a small molecule irreversible inhibitor of MALT1 to identify genes that might confer resistance or enhance the activity of MALT1 inhibition (MALT1i). We find that loss of B-cell receptor (BCR)- and phosphatidylinositol 3-kinase (PI3K)-activating proteins enhanced sensitivity, whereas loss of negative regulators of these pathways (eg, TRAF2, TNFAIP3) promoted resistance. These findings were validated by knockdown of individual genes and a combinatorial drug screen focused on BCR and PI3K pathway-targeting drugs. Among these, the most potent combinatorial effect was observed with PI3Kδ inhibitors against ABC-DLBCLs in vitro and in vivo, but that led to an adaptive increase in phosphorylated S6 and eventual disease progression. Along these lines, MALT1i promoted increased MTORC1 activity and phosphorylation of S6K1-T389 and S6-S235/6, an effect that was only partially blocked by PI3Kδ inhibition in vitro and in vivo. In contrast, simultaneous inhibition of MALT1 and MTORC1 prevented S6 phosphorylation, yielded potent activity against DLBCL cell lines and primary patient specimens, and resulted in more profound tumor regression and significantly improved survival of ABC-DLBCLs in vivo compared with PI3K inhibitors. These findings provide a basis for maximal therapeutic impact of MALT1 inhibitors in the clinic, by disrupting feedback mechanisms that might otherwise limit their efficacy.

Models Predicting Postpartum Glucose Intolerance Among Women with a History of Gestational Diabetes Mellitus: a Systematic Review.

PURPOSE OF REVIEW: Despite the crucial role that prediction models play in guiding early risk stratification and timely intervention to prevent type 2 diabetes after gestational diabetes mellitus (GDM), their use is not widespread in clinical practice. The purpose of this review is to examine the methodological characteristics and quality of existing prognostic models predicting postpartum glucose intolerance following GDM. RECENT FINDINGS: A systematic review was conducted on relevant risk prediction models, resulting in 15 eligible publications from research groups in various countries. Our review found that traditional statistical models were more common than machine learning models, and only two were assessed to have a low risk of bias. Seven were internally validated, but none were externally validated. Model discrimination and calibration were done in 13 and four studies, respectively. Various predictors were identified, including body mass index, fasting glucose concentration during pregnancy, maternal age, family history of diabetes, biochemical variables, oral glucose tolerance test, use of insulin in pregnancy, postnatal fasting glucose level, genetic risk factors, hemoglobin A1c, and weight. The existing prognostic models for glucose intolerance following GDM have various methodological shortcomings, with only a few models being assessed to have low risk of bias and validated internally. Future research should prioritize the development of robust, high-quality risk prediction models that follow appropriate guidelines, in order to advance this area and improve early risk stratification and intervention for glucose intolerance and type 2 diabetes among women who have had GDM.

Advocacy in Action: a Comprehensive Student-Led Proactive Outreach to Patients at Highest Risk.

INTRODUCTION: COVID-19 disrupted access to critical healthcare and resources for many, especially affecting patients at safety-net hospitals who rely on regular care for multiple complex conditions. Students realized they could support patients from the sidelines by helping navigate abrupt healthcare changes and proactively addressing needs at home. AIM: To comprehensively identify and meet the clinical and social needs of Atlanta, Georgia's patients at highest risk, left without their usual access to healthcare, through proactive telephonic outreach. SETTING AND PATIENTS: Medical and Physician's Assistant students from Emory and Morehouse Schools of Medicine partnered with Grady Health System, Atlanta's safety-net hospital. Artificial intelligence prioritized over 15,000 patients by risk of morbidity and mortality from COVID-19. PROGRAM DESCRIPTION: In this novel program, students performed telephonic outreach to thousands of patients at highest risk of poor outcomes from COVID-19. Students used a custom REDCap form that served as both a call script and data collection tool. It provided step-by-step guidance to (1) screen for COVID-19 and educate on prevention; (2) help patients navigate health system changes to fill gaps in care; and (3) identify and address social needs. Based on patients' responses, the form prompted tailored reminders for next steps and connections to medical and social resources. PROGRAM EVALUATION: In the program's first 16 months, students made 7,988 calls, of which 3,354 were answered. Over half (53%) of patients had at least one need requiring action: 48% health and 16% social. DISCUSSION: This proactive, novel initiative identified substantial clinical and social need among patients at highest risk for poor outcomes and filled a pressing health system gap exacerbated by COVID-19. Simultaneously, interprofessional students gained applied exposure to health systems sciences. This program can serve as a model for rapid, cost-effective, high-yield outreach to promote patient health at home both during and beyond the pandemic.

Student-faculty co-creation of experiential learning in health systems science.

INTRODUCTION: Health Systems Science (HSS) teaches students critical skills to navigate complex health systems, yet medical schools often find it difficult to integrate into their curriculum due to limited time and student disinterest. Co-developing content with students and teaching through appropriate experiential learning can improve student engagement in HSS coursework. METHODS: Medical students and faculty co-developed a patient outreach initiative during the early phases of the COVID-19 pandemic and integrated that experience into a new experiential HSS elective beginning May 2020. Students called patients identified as high-risk for adverse health outcomes and followed a script to connect patients to healthcare and social services. Subsequently, this initiative was integrated into the required third-year primary care clerkship. RESULTS: A total of 255 students participated in HSS experiential learning through the elective and clerkship from May 2020 through July 2021. Students reached 3,212 patients, encountering a breadth of medical, social, and health systems issues; navigated the EMR; engaged interdisciplinary professionals; and proposed opportunities for health systems improvement. DISCUSSION AND CONCLUSION: This educational intervention demonstrated the opportunity to partner with student-led initiatives, coproducing meaningful educational experiences for the learners within the confines of a busy medical curriculum.

Facilitators and barriers to behaviour change within a lifestyle program for women with obesity to prevent excess gestational weight gain: a mixed methods evaluation.

BACKGROUND: Maternal obesity is associated with health risks for women and their babies and is exacerbated by excess gestational weight gain. The aim of this study was to describe women's experiences and perspectives in attending a Healthy Pregnancy Service designed to optimise healthy lifestyle and support recommended gestational weight gain for women with obesity. METHODS: An explanatory sequential mixed methods study design utilised two questionnaires (completed in early and late pregnancy) to quantify feelings, motivation and satisfaction with the service, followed by semi-structured interviews that explored barriers and enablers of behaviour change. Data were analysed separately and then interpreted together. RESULTS: Overall, 49 women attending the service completed either questionnaire 1, 2 or both and were included in the analysis. Fourteen women were interviewed. Prior to pregnancy, many women had gained weight and attempted to lose weight independently, and reported they were highly motivated to achieve a healthy lifestyle. During pregnancy, diet changes were reported as easier to make and sustain than exercise changes. Satisfaction with the service was high. Key factors identified in qualitative analysis were: service support enabled change; motivation to change behaviour, social support, barriers to making change (intrinsic, extrinsic and clinic-related), post-partum lifestyle and needs. On integration of data, qualitative and quantitative findings aligned. CONCLUSIONS: The Healthy Pregnancy service was valued by women. Barriers and enablers to the delivery of an integrated model of maternity care that supported healthy lifestyle and recommended gestational weight gain were identified. These findings have informed and improved implementation and further scale up of this successful service model, integrating healthy lifestyle into routine antenatal care of women with obesity. TRIAL REGISTRATION: This trial is registered with the Australian New Zealand Clinical Trials Registry (no.12620000985987). Registration date 30/09/2020, retrospectively registered. http://www.anzctr.org.au/.

Suspected Case of Multisystem Inflammatory Syndrome in Children Associated With SARS-CoV-2 Infection Presenting as Acute Pancreatitis in a Child With Leukemia.

Multisystem inflammatory syndrome in children (MIS-C) associated with SARS-CoV-2 may present with fever, elevated inflammatory markers, and multiorgan involvement. Although the gastrointestinal system is commonly affected in MIS-C patients, associated necrotizing pancreatitis is rare. We present an 11-year-old boy with B-cell acute lymphoblastic leukemia in remission undergoing maintenance chemotherapy presenting with acute necrotizing pancreatitis. He developed fevers, fluid and electrolyte imbalance, respiratory distress, cytopenias, and coagulopathy, and was found to have markedly elevated inflammatory markers and positive SARS-CoV-2 antibodies. The patient met criteria for MIS-C and was treated with intravenous immunoglobulin with significant clinical improvement. This is the first known reported case of a child with B-cell acute lymphoblastic leukemia who met criteria for MIS-C presenting as acute pancreatitis, and highlights the importance of considering a broader differential for pancreatitis in children given the current SARS-CoV-2 pandemic.

Search and Subvert: Minimalist Bacterial Phosphatidylinositol-Specific Phospholipase C Enzymes.

Phosphatidylinositol-specific phospholipase C (PI-PLC) enzymes from Gram-positive bacteria are secreted virulence factors that aid in downregulating host immunity. These PI-PLCs are minimalist peripheral membrane enzymes with a distorted (ßα)8 TIM barrel fold offering a conserved and stable scaffold for the conserved catalytic amino acids while membrane recognition is achieved mostly through variable loops. Decades of experimental and computational research on these enzymes have revealed the subtle interplay between molecular mechanisms of catalysis and membrane binding, leading to a semiquantitative model for how they find, bind, and cleave their respective substrates on host cell membranes. Variations in sequence and structure of their membrane binding sites may correlate with how enzymes from different Gram-positive bacteria search for their particular targets on the membrane. Detailed molecular characterization of protein-lipid interactions have been aided by cutting-edge methods ranging from 31P field-cycling NMR relaxometry to monitor protein-induced changes in phospholipid dynamics to molecular dynamics simulations to elucidate the roles of electrostatic and cation-π interactions in lipid binding to single molecule fluorescence measurements of dynamic interactions between PI-PLCs and vesicles. This toolkit is readily applicable to other peripheral membrane proteins including orthologues in Gram-negative bacteria and more recently discovered eukaryotic minimalist PI-PLCs.

Gestational weight gain across continents and ethnicity: systematic review and meta-analysis of maternal and infant outcomes in more than one million women.

BACKGROUND: The association between Institute of Medicine (IOM) guidelines and pregnancy outcomes across ethnicities is uncertain. We evaluated the associations of gestational weight gain (GWG) outside 2009 IOM guidelines, with maternal and infant outcomes across the USA, western Europe and east Asia, with subgroup analyses in Asia. The aim was to explore ethnic differences in maternal prepregnancy body mass index (BMI), GWG and health outcomes across these regions. METHODS: Systematic review, meta-analysis and meta-regression of observational studies were used for the study. MEDLINE, MEDLINE In-Process, Embase and all Evidence-Based Medicine (EBM) Reviews were searched from 1999 to 2017. Studies were stratified by prepregnancy BMI category and total pregnancy GWG. Odds ratio (ORs) 95% confidence intervals (CI) applied recommended GWG within each BMI category as the reference. Primary outcomes were small for gestational age (SGA), preterm birth and large for gestational age (LGA). Secondary outcomes were macrosomia, caesarean section and gestational diabetes. RESULTS: Overall, 5874 studies were identified and 23 were included (n = 1,309,136). Prepregnancy overweight/obesity in the USA, Europe and Asia was measured at 42%, 30% and 10% respectively, with underweight 5%, 3% and 17%. GWG below guidelines in the USA, Europe and Asia was 21%, 18% and 31%, and above was 51%, 51% and 37% respectively. Applying regional BMI categories in Asia showed GWG above guidelines (51%) was similar to that in the USA and Europe. GWG below guidelines was associated with a higher risk of SGA (USA/Europe [OR 1.51; CI 1.39, 1.63]; Asia [1.63; 1.45, 1.82]) and preterm birth (USA/Europe [1.35; 1.17, 1.56]; Asia [1.06; 0.78, 1.44]) than GWG within guidelines. GWG above guidelines was associated with a higher risk of LGA (USA/Europe [1.93; 1.81, 2.06]; Asia [1.68; 1.51 , 1.87]), macrosomia (USA/Europe [1.87; 1.70, 2.06]; Asia [2.18; 1.91, 2.49]) and caesarean (USA/Europe [1.26; 1.21, 1.33]; Asia [1.37; 1.30, 1.45]). Risks remained elevated when regional BMI categories were applied for GWG recommendations. More women in Asia were categorised as having GWG below guidelines using World Health Organization (WHO) (60%) compared to regional BMI categories (16%), yet WHO BMI was not accompanied by increased risks of adverse outcomes. CONCLUSIONS: Women in the USA and western Europe have higher prepregnancy BMI and higher rates of GWG above guidelines than women in east Asia. However, when using regional BMI categories in east Asia, rates of GWG above guidelines are similar across the three continents. GWG outside guidelines is associated with adverse outcomes across all regions. If regional BMI categories are used in east Asia, IOM guidelines are applicable in the USA, western Europe and east Asia.

Combinatorial targeting of nuclear export and translation of RNA inhibits aggressive B-cell lymphomas.

Aggressive double- and triple-hit (DH/TH) diffuse large B-cell lymphomas (DLBCLs) feature activation of Hsp90 stress pathways. Herein, we show that Hsp90 controls posttranscriptional dynamics of key messenger RNA (mRNA) species including those encoding BCL6, MYC, and BCL2. Using a proteomics approach, we found that Hsp90 binds to and maintains activity of eIF4E. eIF4E drives nuclear export and translation of BCL6, MYC, and BCL2 mRNA. eIF4E RNA-immunoprecipitation sequencing in DLBCL suggests that nuclear eIF4E controls an extended program that includes B-cell receptor signaling, cellular metabolism, and epigenetic regulation. Accordingly, eIF4E was required for survival of DLBCL including the most aggressive subtypes, DH/TH lymphomas. Indeed, eIF4E inhibition induces tumor regression in cell line and patient-derived tumorgrafts of TH-DLBCL, even in the presence of elevated Hsp90 activity. Targeting Hsp90 is typically limited by counterregulatory elevation of Hsp70B, which induces resistance to Hsp90 inhibitors. Surprisingly, we identify Hsp70 mRNA as an eIF4E target. In this way, eIF4E inhibition can overcome drug resistance to Hsp90 inhibitors. Accordingly, rational combinatorial inhibition of eIF4E and Hsp90 inhibitors resulted in cooperative antilymphoma activity in DH/TH DLBCL in vitro and in vivo.

Association of Gestational Weight Gain With Maternal and Infant Outcomes: A Systematic Review and Meta-analysis.

IMPORTANCE: Body mass index (BMI) and gestational weight gain are increasing globally. In 2009, the Institute of Medicine (IOM) provided specific recommendations regarding the ideal gestational weight gain. However, the association between gestational weight gain consistent with theIOM guidelines and pregnancy outcomes is unclear. OBJECTIVE: To perform a systematic review, meta-analysis, and metaregression to evaluate associations between gestational weight gain above or below the IOM guidelines (gain of 12.5-18 kg for underweight women [BMI <18.5]; 11.5-16 kg for normal-weight women [BMI 18.5-24.9]; 7-11 kg for overweight women [BMI 25-29.9]; and 5-9 kg for obese women [BMI ≥30]) and maternal and infant outcomes. DATA SOURCES AND STUDY SELECTION: Search of EMBASE, Evidence-Based Medicine Reviews, MEDLINE, and MEDLINE In-Process between January 1, 1999, and February 7, 2017, for observational studies stratified by prepregnancy BMI category and total gestational weight gain. DATA EXTRACTION AND SYNTHESIS: Data were extracted by 2 independent reviewers. Odds ratios (ORs) and absolute risk differences (ARDs) per live birth were calculated using a random-effects model based on a subset of studies with available data. MAIN OUTCOMES AND MEASURES: Primary outcomes were small for gestational age (SGA), preterm birth, and large for gestational age (LGA). Secondary outcomes were macrosomia, cesarean delivery, and gestational diabetes mellitus. RESULTS: Of 5354 identified studies, 23 (n = 1 309 136 women) met inclusion criteria. Gestational weight gain was below or above guidelines in 23% and 47% of pregnancies, respectively. Gestational weight gain below the recommendations was associated with higher risk of SGA (OR, 1.53 [95% CI, 1.44-1.64]; ARD, 5% [95% CI, 4%-6%]) and preterm birth (OR, 1.70 [1.32-2.20]; ARD, 5% [3%-8%]) and lower risk of LGA (OR, 0.59 [0.55-0.64]; ARD, -2% [-10% to -6%]) and macrosomia (OR, 0.60 [0.52-0.68]; ARD, -2% [-3% to -1%]); cesarean delivery showed no significant difference (OR, 0.98 [0.96-1.02]; ARD, 0% [-2% to 1%]). Gestational weight gain above the recommendations was associated with lower risk of SGA (OR, 0.66 [0.63-0.69]; ARD, -3%; [-4% to -2%]) and preterm birth (OR, 0.77 [0.69-0.86]; ARD, -2% [-2% to -1%]) and higher risk of LGA (OR, 1.85 [1.76-1.95]; ARD, 4% [2%-5%]), macrosomia (OR, 1.95 [1.79-2.11]; ARD, 6% [4%-9%]), and cesarean delivery (OR, 1.30 [1.25-1.35]; ARD, 4% [3%-6%]). Gestational diabetes mellitus could not be evaluated because of the nature of available data. CONCLUSIONS AND RELEVANCE: In this systematic review and meta-analysis of more than 1 million pregnant women, 47% had gestational weight gain greater than IOM recommendations and 23% had gestational weight gain less than IOM recommendations. Gestational weight gain greater than or less than guideline recommendations, compared with weight gain within recommended levels, was associated with higher risk of adverse maternal and infant outcomes.

Untangling the Impacts of Climate Change on Waterborne Diseases: a Systematic Review of Relationships between Diarrheal Diseases and Temperature, Rainfall, Flooding, and Drought.

Global climate change is expected to affect waterborne enteric diseases, yet to date there has been no comprehensive, systematic review of the epidemiological literature examining the relationship between meteorological conditions and diarrheal diseases. We searched PubMed, Embase, Web of Science, and the Cochrane Collection for studies describing the relationship between diarrheal diseases and four meteorological conditions that are expected to increase with climate change: ambient temperature, heavy rainfall, drought, and flooding. We synthesized key areas of agreement and evaluated the biological plausibility of these findings, drawing from a diverse, multidisciplinary evidence base. We identified 141 articles that met our inclusion criteria. Key areas of agreement include a positive association between ambient temperature and diarrheal diseases, with the exception of viral diarrhea and an increase in diarrheal disease following heavy rainfall and flooding events. Insufficient evidence was available to evaluate the effects of drought on diarrhea. There is evidence to support the biological plausibility of these associations, but publication bias is an ongoing concern. Future research evaluating whether interventions, such as improved water and sanitation access, modify risk would further our understanding of the potential impacts of climate change on diarrheal diseases and aid in the prioritization of adaptation measures.

Targeting the Hsp90-associated viral oncoproteome in gammaherpesvirus-associated malignancies.

PU-H71 is a purine-scaffold Hsp90 inhibitor that, in contrast to other Hsp90 inhibitors, displays unique selectivity for binding the fraction of Hsp90 that is preferentially associated with oncogenic client proteins and enriched in tumor cells (teHsp90). This property allows PU-H71 to potently suppress teHsp90 without inducing toxicity in normal cells. We found that lymphoma cells infected by Epstein-Barr virus or Kaposi sarcoma-associated herpes virus (KSHV) are exquisitely sensitive to this compound. Using PU-H71 affinity capture and proteomics, an unbiased approach to reveal oncogenic networks, we identified the teHsp90 interactome in KSHV(+) primary effusion lymphoma cells. Viral and cellular proteins were identified, including many involved in nuclear factor (NF)-κB signaling, apoptosis, and autophagy. KSHV vFLIP is a viral oncoprotein homologous to cFLIPs, with NF-κB-activating and antiapoptotic activities. We show that teHsp90 binds vFLIP but not cFLIPs. Treatment with PU-H71 induced degradation of vFLIP and IKKγ, NF-κB downregulation, apoptosis and autophagy in vitro, and more importantly, tumor responses in mice. Analysis of the interactome revealed apoptosis as a central pathway; therefore, we tested a BCL2 family inhibitor in primary effusion lymphoma cells. We found strong activity and synergy with PU-H71. Our findings demonstrate PU-H71 affinity capture identifies actionable networks that may help design rational combinations of effective therapies.

The cation-π box is a specific phosphatidylcholine membrane targeting motif.

Peripheral membrane proteins can be targeted to specific organelles or the plasma membrane by differential recognition of phospholipid headgroups. Although molecular determinants of specificity for several headgroups, including phosphatidylserine and phosphoinositides are well defined, specific recognition of the headgroup of the zwitterionic phosphatidylcholine (PC) is less well understood. In cytosolic proteins the cation-π box provides a suitable receptor for choline recognition and binding through the trimethylammonium moiety. In PC, this moiety might provide a sufficient handle to bind to peripheral proteins via a cation-π cage, where the π systems of two or more aromatic residues are within 4-5 Å of the quaternary amine. We prove this hypothesis by engineering the cation-π box into secreted phosphatidylinositol-specific phospholipase C from Staphylococcus aureus, which lacks specific PC recognition. The N254Y/H258Y variant selectively binds PC-enriched vesicles, and x-ray crystallography reveals N254Y/H258Y binds choline and dibutyroylphosphatidylcholine within the cation-π motif. Such simple PC recognition motifs could be engineered into a wide variety of secondary structures providing a generally applicable method for specific recognition of PC.

Serum selenium status in Graves' disease with and without orbitopathy: a case-control study.

OBJECTIVE: Selenium is effective in improving quality of life and reducing the progression of active Graves' orbitopathy. The effect of correcting relative selenium deficiency on improving Graves' orbitopathy is unknown, as baseline selenium levels have not previously been measured. The study aims to determine whether serum selenium levels are reduced in patients with Graves' disease with orbitopathy (GO) compared with without orbitopathy (GD). DESIGN: A prospective, case-control study performed between 2009 and 2012 at endocrine and ophthalmology clinics in Australia. PATIENTS: A total of 198 patients with Graves' disease participated in the study: 101 with Graves' orbitopathy and 97 without Graves' orbitopathy. MEASUREMENTS: Serum selenium levels in both groups. RESULTS: Mean serum selenium levels were significantly lower in GO (1·10 ± 0·18 µm) than in GD (1·19 ± 0·20 µm) (P = 0·001). Mean selenium levels appeared to decrease in parallel with increasing severity of GO; selenium level was 1·19 ± 0·20 µm in GD, 1·10 ± 0·19 µm in moderate-to-severe GO and 1·09 ± 0·17 µm in sight-threatening GO (P = 0·003). Serum selenium levels remained significantly lower in GO after adjusting for age, smoking status, thyroidectomy, radioactive iodine treatment and residential location. CONCLUSION: Serum selenium levels are lower in patients with GO compared with GD in an Australian study population with marginal selenium status. Relative selenium deficiency may be an independent risk factor for orbitopathy in patients with Graves' disease.

Identifying Predictor Variables for a Composite Risk Prediction Tool for Gestational Diabetes and Hypertensive Disorders of Pregnancy: A Modified Delphi Study.

A composite cardiometabolic risk prediction tool will support the systematic identification of women at increased cardiometabolic risk during pregnancy to enable early screening and intervention. This study aims to identify and select predictor variables for a composite risk prediction tool for cardiometabolic risk (gestational diabetes mellitus and/or hypertensive disorders of pregnancy) for use in the first trimester. A two-round modified online Delphi study was undertaken. A prior systematic literature review generated fifteen potential predictor variables for inclusion in the tool. Multidisciplinary experts (n = 31) rated the clinical importance of variables in an online survey and nominated additional variables for consideration (Round One). An online meeting (n = 14) was held to deliberate the importance, feasibility and acceptability of collecting variables in early pregnancy. Consensus was reached in a second online survey (Round Two). Overall, 24 variables were considered; 9 were eliminated, and 15 were selected for inclusion in the tool. The final 15 predictor variables related to maternal demographics (age, ethnicity/race), pre-pregnancy history (body mass index, height, history of chronic kidney disease/polycystic ovarian syndrome, family history of diabetes, pre-existing diabetes/hypertension), obstetric history (parity, history of macrosomia/pre-eclampsia/gestational diabetes mellitus), biochemical measures (blood glucose levels), hemodynamic measures (systolic blood pressure). Variables will inform the development of a cardiometabolic risk prediction tool in subsequent research. Evidence-based, clinically relevant and routinely collected variables were selected for a composite cardiometabolic risk prediction tool for early pregnancy.

Can an intervention designed to reduce repetitive negative thinking alter the response to a psychosocial stressor? A randomized controlled study.

Prior research suggests that repetitive negative thinking (RNT) negatively impacts mental health by intensifying and prolonging emotional reactivity to stress. This study investigated whether an intervention designed to reduce RNT alters emotional reactivity. Young adults with high trait RNT (N = 79) were randomly allocated to an RNT-focused intervention (smartphone app-based, 10 days) or a waiting list before exposure to a standardized stressor. The pre-registered analysis did not reveal a significant condition * time interaction for negative affect. However, exploratory analyses showed that whilst initial increases in negative affect in response to the stressor did not differ between conditions, participants in the intervention condition reported less negative affect throughout the following recovery phase. Additionally, participants in the intervention condition appraised their ability to cope with the stressor as higher and reported less RNT in the recovery phase. In contrast, the intervention did not affect biological stress responses. The findings indicate that RNT-focused interventions might have positive effects on mental health by breaking the self-reinforcing cycle of RNT, negative affect and maladaptive appraisals in response to stress. However, as findings are partly based on exploratory analyses, further research is needed to confirm whether reduced subjective stress reactivity mediates the effects of RNT-focused interventions on psychopathological symptoms.

Development of a risk prediction model for postpartum onset of type 2 diabetes mellitus, following gestational diabetes; the lifestyle InterVention in gestational diabetes (LIVING) study.

AIMS: This study aimed to develop a prediction model for identifying a woman with gestational diabetes mellitus (GDM) at high risk of type 2 diabetes (T2DM) post-birth. METHODS: Utilising data from 1299 women in the Lifestyle Intervention IN Gestational Diabetes (LIVING) study, two models were developed: one for pregnancy and another for postpartum. Key predictors included glucose test results, medical history, and biometric indicators. RESULTS: Of the initial cohort, 124 women developed T2DM within three years. The study identified seven predictors for the antenatal T2DM risk prediction model and four for the postnatal one. The models demonstrated good to excellent predictive ability, with Area under the ROC Curve (AUC) values of 0.76 (95% CI: 0.72 to 0.80) and 0.85 (95% CI: 0.81 to 0.88) for the antenatal and postnatal models, respectively. Both models underwent rigorous validation, showing minimal optimism in predictive capability. Antenatal model, considering the Youden index optimal cut-off point of 0.096, sensitivity, specificity, and accuracy were measured as 70.97%, 70.81%, and 70.82%, respectively. For the postnatal model, considering the cut-off point 0.086, sensitivity, specificity, and accuracy were measured as 81.40%, 75.60%, and 76.10%, respectively. CONCLUSIONS: These models are effective for predicting T2DM risk in women with GDM, although external validation is recommended before widespread application.

Competition between anion binding and dimerization modulates Staphylococcus aureus phosphatidylinositol-specific phospholipase C enzymatic activity.

BACKGROUND: Bacterial phosphatidylinositol-specific phospholipase C targets PI and glycosylphosphatidylinositol-linked proteins of eukaryotic cells. RESULTS: Functional relevance of a homodimeric S. aureus PI-PLC crystal structure is supported by enzyme kinetics and mutagenesis. Nonsubstrate phosphatidylcholine increases activity by facilitating enzyme dimerization. CONCLUSION: Activating transient dimerization is antagonized by anions binding to a discrete site. SIGNIFICANCE: Interplay of protein oligomerization and anion binding controls enzyme activity. Staphylococcus aureus phosphatidylinositol-specific phospholipase C (PI-PLC) is a secreted virulence factor for this pathogenic bacterium. A novel crystal structure shows that this PI-PLC can form a dimer via helix B, a structural feature present in all secreted, bacterial PI-PLCs that is important for membrane binding. Despite the small size of this interface, it is critical for optimal enzyme activity. Kinetic evidence, increased enzyme specific activity with increasing enzyme concentration, supports a mechanism where the PI-PLC dimerization is enhanced in membranes containing phosphatidylcholine (PC). Mutagenesis of key residues confirm that the zwitterionic phospholipid acts not by specific binding to the protein, but rather by reducing anionic lipid interactions with a cationic pocket on the surface of the S. aureus enzyme that stabilizes monomeric protein. Despite its structural and sequence similarity to PI-PLCs from other Gram-positive pathogenic bacteria, S. aureus PI-PLC appears to have a unique mechanism where enzyme activity is modulated by competition between binding of soluble anions or anionic lipids to the cationic sensor and transient dimerization on the membrane.

Women with polycystic ovary syndrome have intrinsic insulin resistance on euglycaemic-hyperinsulaemic clamp.

STUDY QUESTION: What is the prevalence of insulin resistance (IR) and the contributions of intrinsic and extrinsic IR in women diagnosed with polycystic ovary syndrome (PCOS) according to the Rotterdam criteria? SUMMARY ANSWER: We report novel clamp data in Rotterdam diagnosed PCOS women, using World Health Organization criteria for IR showing that women with PCOS have a high prevalence of IR, strengthening the evidence for an aetiological role of IR in both National Institutes of Health (NIH) and Rotterdam diagnosed PCOS in lean and overweight women. WHAT IS KNOWN ALREADY: PCOS is a complex endocrine condition with a significant increased risk of gestational diabetes and type 2 diabetes. STUDY DESIGN, SIZE, DURATION: Using a cross-sectional study design, 20 overweight and 20 lean PCOS (Rotterdam criteria), 14 overweight and 19 lean body mass index (BMI)-matched control non-PCOS women underwent clinical measures of IR after a 3-month withdrawal of insulin sensitizers and the oral contraceptive pill. MATERIALS, SETTING, METHODS: In an academic clinic setting, glucose infusion rate (GIR) on euglycaemic-hyperinsulinaemic clamp was investigated as a marker of insulin sensitivity. MAIN RESULTS AND THE ROLE OF CHANCE: PCOS women were more IR than BMI-matched controls (main effect for BMI and PCOS; P < 0.001). IR was present in 75% of lean PCOS, 62% of overweight controls and 95% of overweight PCOS. Lean controls (mean ± SD; GIR 339 ± 76 mg min⁻¹ m⁻²) were less IR than lean PCOS (270 ± 66 mg min⁻¹ m⁻²), overweight controls (264 ± 66 mg min⁻¹ m⁻²) and overweight PCOS (175 ± 96 mg min⁻¹ m⁻²). The negative relationship between BMI and IR reflected by GIR was more marked in PCOS (y = 445.1 - 7.7x, R² = 0.42 (P < 0.0001) than controls (y = 435.5 - 4.6x, R² = 0.04 (P < 0.01)). LIMITATIONS, REASONS FOR CAUTION: The study did not use glucose tracer techniques to completely characterize the IR, as well as the lack of matching for body composition and age. WIDER IMPLICATIONS OF THE FINDINGS: IR is exacerbated by increased BMI, supporting intrinsic IR in PCOS. BMI impact on IR is greater in PCOS, than in controls, irrespective of visceral fat, prioritizing lifestyle intervention and the need for effective therapeutic interventions to address intrinsic IR and prevent diabetes in this high-risk population. STUDY FUNDING/COMPETING INTEREST(S): This investigator-initiated trial was supported by grants from the National Health & Medical Research Council (NHMRC) Grant number 606553 (H.J.T., N.K.S. and S.K.H.) as well as Monash University and The Jean Hailes Foundation. H.J.T. is an NHMRC Research Fellow. N.K.S. is supported through the Australian Government's Collaborative Research Networks (CRN) programme. A.E.J. is a Jean Hailes and NHMRC scholarship holder. The authors declare that there is no conflict of interest associated with this manuscript.

Neuronal caspase 2 activity and function requires RAIDD, but not PIDD.

Caspase 2 was initially identified as a neuronally expressed developmentally down-regulated gene (HUGO gene nomenclature CASP2) and has been shown to be required for neuronal death induced by several stimuli, including NGF (nerve growth factor) deprivation and Aß (ß-amyloid). In non-neuronal cells the PIDDosome, composed of caspase 2 and two death adaptor proteins, PIDD (p53-inducible protein with a death domain) and RAIDD {RIP (receptor-interacting protein)-associated ICH-1 [ICE (interleukin-1ß-converting enzyme)/CED-3 (cell-death determining 3) homologue 1] protein with a death domain}, has been proposed as the caspase 2 activation complex, although the absolute requirement for the PIDDosome is not clear. To investigate the requirement for the PIDDosome in caspase-2-dependent neuronal death, we have examined the necessity for each component in induction of active caspase 2 and in execution of caspase-2-dependent neuronal death. We find that both NGF deprivation and Aß treatment of neurons induce active caspase 2 and that induction of this activity depends on expression of RAIDD, but is independent of PIDD expression. We show that treatment of wild-type or PIDD-null neurons with Aß or NGF deprivation induces formation of a complex of caspase 2 and RAIDD. We also show that caspase-2-dependent execution of neurons requires RAIDD, not PIDD. Caspase 2 activity can be induced in neurons from PIDD-null mice, and NGF deprivation or Aß use caspase 2 and RAIDD to execute death of these neurons.