An Augmented Negative Force-Frequency Relationship and Slowed Mechanical Restitution Are Associated With Increased Susceptibility to Drug-Induced Torsade de Pointes Arrhythmias in the Chronic Atrioventricular Block Dog

Introduction: In the chronic AV-block (CAVB) dog model, structural, contractile, and electrical remodeling occur, which predispose the heart to dofetilide-induced Torsade de Pointes (TdP) arrhythmias. Previous studies found a relation between electrical remodeling and inducibility of TdP, while structural remodeling is not a prerequisite for arrhythmogenesis. In this study, we prospectively assessed the relation between in vivo markers of contractile remodeling and TdP inducibility.Methods: In 18 anesthetized dogs, the maximal first derivative of left ventricular pressure (LV dP/dtmax) was assessed at acute AV-block (AAVB) and after 2 weeks of chronic AV-block (CAVB2). Using pacing protocols, three markers of contractile remodeling, i.e., force-frequency relationship (FFR), mechanical restitution (MR), and post-extrasystolic potentiation (PESP) were determined. Infusion of dofetilide (0.025 mg/kg in 5 min) was used to test for TdP inducibility.Results: After infusion of dofetilide, 1/18 dogs and 12/18 were susceptible to TdP-arrhythmias at AAVB and CAVB2, respectively (p = 0.001). The inducible dogs at CAVB2 showed augmented contractility at a CL of 1200 ms (2354 ± 168 mmHg/s in inducible dogs versus 1091 ± 59 mmHg/s in non-inducible dogs, p < 0.001) with a negative FFR, while the non-inducible dogs retained their positive FFR. The time constant (TC) of the MR curve was significantly higher in the inducible dogs (158 ± 7 ms versus 97 ± 8 ms, p < 0.0001). Furthermore, a linear correlation was found between a weighted score of the number and severity of arrhythmias and contractile parameters, i.e., contractility at CL of 1200 ms (r = 0.73, p = 0.002), the slope of the FFR (r = -0.58, p = 0.01) and the TC of MR (r = 0.66, p = 0.003). Thus, more severe arrhythmias were seen in dogs with the most pronounced contractile remodeling.Conclusion: Contractile remodeling is concomitantly observed with susceptibility to dofetilide-induced TdP-arrhythmias. The inducible dogs show augmented contractile remodeling compared to non-inducible dogs, as seen by a negative FFR, higher maximal response of MR and PESP and slowed MR kinetics. These altered contractility parameters could reflect disrupted Ca2+ handling and Ca2+-overload, which predispose the heart to delayed- and early afterdepolarizations that could trigger TdP-arrhythmias

Study protocol for two randomised controlled trials evaluating the effects of Cerclage in the reduction of extreme preterm birth and perinatal mortality in twin pregnancies with a short cervix or dilatation:The TWIN Cerclage studies

Introduction:Twin pregnancies have a high risk of extreme preterm birth (PTB) at less than 28 weeks of gestation, which is associated with increased risk of neonatal morbidity and mortality. Currently there is a lack of effective treatments for women with a twin pregnancy and a short cervix or cervical dilatation. A possible effective surgical method to reduce extreme PTB in twin pregnancies with an asymptomatic short cervix or dilatation at midpregnancy is the placement of a vaginal cerclage. Methods and analysis: We designed two multicentre randomised trials involving eight hospitals in the Netherlands (sites in other countries may be added at a later date). Women older than 16 years with a twin pregnancy at &lt;24 weeks of gestation and an asymptomatic short cervix of ≤25 mm or cervical dilatation will be randomly allocated (1:1) to both trials on vaginal cerclage and standard treatment according to the current Dutch Society of Obstetrics and Gynaecology guideline (no cerclage). Permuted blocks sized 2 and 4 will be used to minimise the risk of disbalance. The primary outcome measure is PTB of &lt;28 weeks. Analyses will be by intention to treat. The first trial is to demonstrate a risk reduction from 25% to 10% in the short cervix group, for which 194 patients need to be recruited. The second trial is to demonstrate a risk reduction from 80% to 35% in the dilatation group and will recruit 44 women. A cost-effectiveness analysis will be performed from a societal perspective. Ethics and dissemination: This study has been approved by the Research Ethics Committees in the Netherlands on 3/30/2023. Participants will be required to sign an informed consent form. The results will be presented at conferences and published in a peer-reviewed journal. Participants will be informed about the results.</p

Study protocol for two randomised controlled trials evaluating the effects of Cerclage in the reduction of extreme preterm birth and perinatal mortality in twin pregnancies with a short cervix or dilatation:The TWIN Cerclage studies

Introduction:Twin pregnancies have a high risk of extreme preterm birth (PTB) at less than 28 weeks of gestation, which is associated with increased risk of neonatal morbidity and mortality. Currently there is a lack of effective treatments for women with a twin pregnancy and a short cervix or cervical dilatation. A possible effective surgical method to reduce extreme PTB in twin pregnancies with an asymptomatic short cervix or dilatation at midpregnancy is the placement of a vaginal cerclage. Methods and analysis: We designed two multicentre randomised trials involving eight hospitals in the Netherlands (sites in other countries may be added at a later date). Women older than 16 years with a twin pregnancy at &lt;24 weeks of gestation and an asymptomatic short cervix of ≤25 mm or cervical dilatation will be randomly allocated (1:1) to both trials on vaginal cerclage and standard treatment according to the current Dutch Society of Obstetrics and Gynaecology guideline (no cerclage). Permuted blocks sized 2 and 4 will be used to minimise the risk of disbalance. The primary outcome measure is PTB of &lt;28 weeks. Analyses will be by intention to treat. The first trial is to demonstrate a risk reduction from 25% to 10% in the short cervix group, for which 194 patients need to be recruited. The second trial is to demonstrate a risk reduction from 80% to 35% in the dilatation group and will recruit 44 women. A cost-effectiveness analysis will be performed from a societal perspective. Ethics and dissemination: This study has been approved by the Research Ethics Committees in the Netherlands on 3/30/2023. Participants will be required to sign an informed consent form. The results will be presented at conferences and published in a peer-reviewed journal. Participants will be informed about the results.</p

The Doctor’s New Clothes: Professional or Fashionable?

Abstract Objective: To investigate the influence of the GP’s attire on the confidence that patients have in their GP as a medical expert and on the patient’s comfort level (defined as ‘feel at ease’). Design: A cross-section study without control group. Methods: Participants (n=1506 ) completed a survey on the internet or in paper after seeing images of six models of three different age categories, each in five different clothing styles (leisure clothing, casual, semiformal, formal and professional). The following questions were asked for each model: “In which doctor do you have the most confidence as a medical expert?” and “With which doctor do you feel most at ease?”. Results: Patients trusted a female doctor and the older male doctor most when wearing professional clothing (white coat). The young and middle aged GP’s were preferred to wear semiformal attire. Patients were most at ease with a female GP wearing leisure clothing. They preferred the young and middle aged male GP to wear semiformal attire, while patients were most at ease with the older male GP wearing casual clothing. Conclusion: The GP’s attire has an influence on the patient’s confidence and comfort level. In general patients still mainly prefer a doctor in a professional outfit.status: publishe

Design of the ZWOT-CASE study : An observational study on the effectiveness of an integrated programme for cardiovascular risk management compared to usual care in general practice

Background: Cardiovascular diseases (CVD) contribute considerably to mortality and morbidity. Prevention of CVD by lifestyle change and medication is important and needs full attention. In the Netherlands an integrated programme for cardiovascular risk management (CVRM), based on the Chronic Care Model (CCM), has been introduced in primary care in many regions in recent years, but its effects are unknown. In the ZWOT-CASE study we will assess the effect of integrated care for CVRM in the region of Zwolle on two major cardiovascular risk factors: systolic blood pressure (SBP) and low-density lipoprotein cholesterol (LDL-cholesterol) in patients with or at high risk of CVD. Methods: This study is a pragmatic observational study comparing integrated care for CVRM with usual care among patients aged 40-80 years with CVD (n = 370) or with a high CVD risk (n = 370) within 26 general practices. After 1 yr follow-up, primary outcomes (SBP and LDL-cholesterol level) are measured. Secondary outcomes include lifestyle habits (smoking, dietary habits, alcohol use, physical activity), risk factor awareness, 10-year risk of cardiovascular morbidity or mortality, health care consumption, patient satisfaction and quality of life. Conclusion: The ZWOT-CASE study will provide insight in the effects of integrated care for CVRM in general practice in patients with CVD or at high CVD risk. Trial registration: The ZWOlle Transmural Integrated Care for CArdiovaScular Risk Management Study; ClinicalTrials.gov; Identifier: NCT03428061; date of registration: 09-02-2018; This study has been retrospectively registered

Design of the ZWOT-CASE study:an observational study on the effectiveness of an integrated programme for cardiovascular risk management compared to usual care in general practice

Background: Cardiovascular diseases (CVD) contribute considerably to mortality and morbidity. Prevention of CVD by lifestyle change and medication is important and needs full attention. In the Netherlands an integrated programme for cardiovascular risk management (CVRM), based on the Chronic Care Model (CCM), has been introduced in primary care in many regions in recent years, but its effects are unknown. In the ZWOT-CASE study we will assess the effect of integrated care for CVRM in the region of Zwolle on two major cardiovascular risk factors: systolic blood pressure (SBP) and low-density lipoprotein cholesterol (LDL-cholesterol) in patients with or at high risk of CVD. Methods: This study is a pragmatic observational study comparing integrated care for CVRM with usual care among patients aged 40-80 years with CVD (n = 370) or with a high CVD risk (n = 370) within 26 general practices. After 1 yr follow-up, primary outcomes (SBP and LDL-cholesterol level) are measured. Secondary outcomes include lifestyle habits (smoking, dietary habits, alcohol use, physical activity), risk factor awareness, 10-year risk of cardiovascular morbidity or mortality, health care consumption, patient satisfaction and quality of life. Conclusion: The ZWOT-CASE study will provide insight in the effects of integrated care for CVRM in general practice in patients with CVD or at high CVD risk. Trial registration: The ZWOlle Transmural Integrated Care for CArdiovaScular Risk Management Study; ClinicalTrials.gov; Identifier: NCT03428061; date of registration: 09-02-2018; This study has been retrospectively registered

Integrated cardiovascular risk management programme versus usual care in patients at high cardiovascular risk:an observational study in general practice

BACKGROUND: Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Despite the impact of CVDs, risk factors are often insufficiently controlled in patients at high risk. Recently, integrated multidisciplinary cardiovascular risk management (CVRM) programmes have been introduced in primary care. AIM: To investigate the effects of a CVRM programme on systolic blood pressure (SBP) and low-density lipoprotein (LDL)-cholesterol. DESIGN & SETTING: A prospective observational study was undertaken in patients at high cardiovascular (CV) risk who were aged 40–80 years. Integrated CVRM care was compared with usual care in general practice in the Netherlands. METHOD: Intervention and usual care patients were matched at baseline on age, sex, and presence of CVD. During 1 year of follow-up, patients received integrated or usual CVRM care in general practice. Primary outcomes were SBP and LDL-cholesterol. Secondary outcomes included calculated 10-year CV risk, body mass index (BMI), lifestyle (smoking, physical activity, and dietary habits), medication use, patient satisfaction, healthcare consumption, morbidity, comorbidity, and mortality. Mixed-model analyses were used to assess the outcomes. RESULTS: Totals of 372 and 317 patients were included in the intervention and usual care group, respectively. Mean age at baseline was 65.1 years and 66.2 years, respectively, and 42% were female in both groups. After 1 year, no differences were observed in: SBP (137.2 mmHg versus 139.0 mmHg in the intervention and usual care group, respectively); LDL-cholesterol (2.6 mmol/l in both groups); or in any of the secondary outcomes. CONCLUSION: Integrated CVRM care in general practice did not lead to a lower SBP or LDL-cholesterol in patients at high CV risk. Further research is needed to improve CVRM

Human male meiotic sex chromosome inactivation.

Contains fulltext : 108163.pdf (publisher's version ) (Open Access)In mammalian male gametogenesis the sex chromosomes are distinctive in both gene activity and epigenetic strategy. At first meiotic prophase the heteromorphic X and Y chromosomes are placed in a separate chromatin domain called the XY body. In this process, X,Y chromatin becomes highly phosphorylated at S139 of H2AX leading to the repression of gonosomal genes, a process known as meiotic sex chromosome inactivation (MSCI), which has been studied best in mice. Post-meiotically this repression is largely maintained. Disturbance of MSCI in mice leads to harmful X,Y gene expression, eventuating in spermatocyte death and sperm heterogeneity. Sperm heterogeneity is a characteristic of the human male. For this reason we were interested in the efficiency of MSCI in human primary spermatocytes. We investigated MSCI in pachytene spermatocytes of seven probands: four infertile men and three fertile controls, using direct and indirect in situ methods. A considerable degree of variation in the degree of MSCI was detected, both between and within probands. Moreover, in post-meiotic stages this variation was observed as well, indicating survival of spermatocytes with incompletely inactivated sex chromosomes. Furthermore, we investigated the presence of H3K9me3 posttranslational modifications on the X and Y chromatin. Contrary to constitutive centromeric heterochromatin, this heterochromatin marker did not specifically accumulate on the XY body, with the exception of the heterochromatic part of the Y chromosome. This may reflect the lower degree of MSCI in man compared to mouse. These results point at relaxation of MSCI, which can be explained by genetic changes in sex chromosome composition during evolution and candidates as a mechanism behind human sperm heterogeneity