Bile acids induce IL-1α and drive NLRP3 inflammasome-independent production of IL-1ß in murine dendritic cells.

Bile acids are amphipathic molecules that are synthesized from cholesterol in the liver and facilitate intestinal absorption of lipids and nutrients. They are released into the small intestine upon ingestion of a meal where intestinal bacteria can modify primary into secondary bile acids. Bile acids are cytotoxic at high concentrations and have been associated with inflammatory diseases such as liver inflammation and Barrett's Oesophagus. Although bile acids induce pro-inflammatory signalling, their role in inducing innate immune cytokines and inflammation has not been fully explored to date. Here we demonstrate that the bile acids, deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA) induce IL-1α and IL-1ß secretion in vitro in primed bone marrow derived dendritic cells (BMDCs). The secretion of IL-1ß was found not to require expression of NLRP3, ASC or caspase-1 activity; we can't rule out all inflammasomes. Furthermore, DCA and CDCA were shown to induce the recruitment of neutrophils and monocytes to the site of injection an intraperitoneal model of inflammation. This study further underlines a mechanistic role for bile acids in the pathogenesis of inflammatory diseases through stimulating the production of pro-inflammatory cytokines and recruitment of innate immune cells.

Extensive remodelling of the cell wall during the development of Staphylococcus aureus bacteraemia.

The bloodstream represents a hostile environment that bacteria must overcome to cause bacteraemia. To understand how the major human pathogen Staphylococcus aureus manages this we have utilised a functional genomics approach to identify a number of new loci that affect the ability of the bacteria to survive exposure to serum, the critical first step in the development of bacteraemia. The expression of one of these genes, tcaA, was found to be induced upon exposure to serum, and we show that it is involved in the elaboration of a critical virulence factor, the wall teichoic acids (WTA), within the cell envelope. The activity of the TcaA protein alters the sensitivity of the bacteria to cell wall attacking agents, including antimicrobial peptides, human defence fatty acids, and several antibiotics. This protein also affects the autolytic activity and lysostaphin sensitivity of the bacteria, suggesting that in addition to changing WTA abundance in the cell envelope, it also plays a role in peptidoglycan crosslinking. With TcaA rendering the bacteria more susceptible to serum killing, while simultaneously increasing the abundance of WTA in the cell envelope, it was unclear what effect this protein may have during infection. To explore this, we examined human data and performed murine experimental infections. Collectively, our data suggests that whilst mutations in tcaA are selected for during bacteraemia, this protein positively contributes to the virulence of S. aureus through its involvement in altering the cell wall architecture of the bacteria, a process that appears to play a key role in the development of bacteraemia.

European Society of Hypertension recommendations for the validation of cuffless blood pressure measuring devices: European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability.

BACKGROUND: There is intense effort to develop cuffless blood pressure (BP) measuring devices, and several are already on the market claiming that they provide accurate measurements. These devices are heterogeneous in measurement principle, intended use, functions, and calibration, and have special accuracy issues requiring different validation than classic cuff BP monitors. To date, there are no generally accepted protocols for their validation to ensure adequate accuracy for clinical use. OBJECTIVE: This statement by the European Society of Hypertension (ESH) Working Group on BP Monitoring and Cardiovascular Variability recommends procedures for validating intermittent cuffless BP devices (providing measurements every >30 sec and usually 30-60 min, or upon user initiation), which are most common. VALIDATION PROCEDURES: Six validation tests are defined for evaluating different aspects of intermittent cuffless devices: static test (absolute BP accuracy); device position test (hydrostatic pressure effect robustness); treatment test (BP decrease accuracy); awake/asleep test (BP change accuracy); exercise test (BP increase accuracy); and recalibration test (cuff calibration stability over time). Not all these tests are required for a given device. The necessary tests depend on whether the device requires individual user calibration, measures automatically or manually, and takes measurements in more than one position. CONCLUSION: The validation of cuffless BP devices is complex and needs to be tailored according to their functions and calibration. These ESH recommendations present specific, clinically meaningful, and pragmatic validation procedures for different types of intermittent cuffless devices to ensure that only accurate devices will be used in the evaluation and management of hypertension.

Requirements for design and function of blood pressure measuring devices used for the management of hypertension: Consensus Statement by the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability and STRIDE BP.

OBJECTIVE: To develop scientific consensus recommendations for the optimal design and functions of different types of blood pressure (BP) measuring devices used in clinical practice for the detection, management, and long-term follow-up of hypertension. METHODS: A scientific consensus meeting was performed by the European Society of Hypertension (ESH) Working Group on BP Monitoring and Cardiovascular Variability and STRIDE BP (Science and Technology for Regional Innovation and Development in Europe) during the 2022 Scientific Meeting of the ESH in Athens, Greece. Manufacturers were also invited to provide their feedback on BP device design and development. Thirty-one international experts in clinical hypertension and BP monitoring contributed to the development of consensus recommendations on the optimal design of BP devices. STATEMENT: International consensus was reached on the requirements for the design and features of five types of BP monitors, including office (or clinic) BP monitors, ambulatory BP monitors, home BP monitors, home BP telemonitors, and kiosk BP monitors for public spaces. For each device type "essential" requirements (must have), and "optional" ones (may have) are presented, as well as additional comments on the optimal device design and features. CONCLUSIONS: These consensus recommendations aim at providing manufacturers of BP devices with the requirements that are considered mandatory, or optional, by clinical experts involved in the detection and management of hypertension. They are also directed to administrative healthcare personnel involved in the provision and purchase of BP devices so that they can recommend the most appropriate ones.

The contribution of competing mechanisms in stroke despite anticoagulation in patients with atrial fibrillation.

BACKGROUND: For reasons poorly understood, strokes frequently occur in patients with atrial fibrillation (AF) despite oral anticoagulation. Better data are needed to inform randomised trials (RCTs) of new strategies to prevent recurrence in these patients. We investigate the relative contribution of competing stroke mechanisms in patients with AF who have stroke despite anticoagulation (OAC+) compared with those who are anticoagulant naïve (OAC-) at the time of their event. PATIENTS AND METHODS: We performed a cross-sectional study leveraging data from a prospective stroke registry (2015-2022). Eligible patients had ischemic stroke and AF. Stroke classification was performed by a single stroke-specialist blinded to OAC status using TOAST criteria. The presence of atherosclerotic plaque was determined using duplex ultrasonography, computerised tomography (CT) or magnetic resonance (MR) angiography. Imaging was reviewed by a single reader. Logistic regression was used to identify independent predictors of stroke despite anticoagulation. RESULTS: Of 596 patients included, 198 (33.2%) were in the OAC+ group. A competing cause for stroke was more frequent in patients with OAC+ versus OAC- (69/198 (34.8%)) versus 77/398 (19.3%), p < 0.001). After adjustment, both small vessel occlusion (odds ratio (OR): 2.46, 95% CI: 1.20-5.06) and arterial atheroma (⩾50% stenosis) (OR: 1.78, 95% CI: 1.07-2.94) were independently associated with stroke despite anticoagulation. DISCUSSION AND CONCLUSION: Patients with AF-associated stroke despite OAC are much more likely than patients who are OAC-naïve to have competing stroke mechanisms. Rigorous investigation for alternative stroke causes in stroke despite OAC has a high diagnostic yield. These data should be used to guide patient selection for future RCTs in this population.

Extensive re-modelling of the cell wall during the development of Staphylococcus aureus bacteraemia.

The bloodstream represents a hostile environment that bacteria must overcome to cause bacteraemia. To understand how the major human pathogen Staphylococcus aureus manages this we have utilised a functional genomics approach to identify a number of new loci that affect the ability of the bacteria to survive exposure to serum, the critical first step in the development of bacteraemia. The expression of one of these genes, tcaA, was found to be induced upon exposure to serum, and we show that it is involved in the elaboration of a critical virulence factor, the wall teichoic acids (WTA), within the cell envelope. The activity of the TcaA protein alters the sensitivity of the bacteria to cell wall attacking agents, including antimicrobial peptides, human defence fatty acids, and several antibiotics. This protein also affects the autolytic activity and lysostaphin sensitivity of the bacteria, suggesting that in addition to changing WTA abundance in the cell envelope, it also plays a role in peptidoglycan crosslinking. With TcaA rendering the bacteria more susceptible to serum killing, while simultaneously increasing the abundance of WTA in the cell envelope, it was unclear what effect this protein may have during infection. To explore this, we examined human data and performed murine experimental infections. Collectively, our data suggests that whilst mutations in tcaA are selected for during bacteraemia, this protein positively contributes to the virulence of S. aureus through its involvement in altering the cell wall architecture of the bacteria, a process that appears to play a key role in the development of bacteraemia.

Predictive power of 24-h ambulatory pulse pressure and its components for mortality and cardiovascular outcomes in 11 848 participants recruited from 13 populations.

BACKGROUND: The role of pulse pressure (PP) 'widening' at older and younger age as a cardiovascular risk factor is still controversial. Mean PP, as determined from repeated blood pressure (BP) readings, can be expressed as a sum of two components: 'elastic PP' (elPP) and 'stiffening PP' (stPP) associated, respectively, with stiffness at the diastole and its relative change during the systole. We investigated the association of 24-h ambulatory PP, elPP, and stPP ('PP variables') with mortality and composite cardiovascular events in different age classes. METHOD: Longitudinal population-based cohort study of adults with baseline observations that included 24-h ambulatory BP. Age classes were age 40 or less, 40-50, 50-60, 60-70, and over 70 years. Co-primary endpoints were total mortality and composite cardiovascular events. The relative risk expressed by hazard ratio per 1SD increase for each of the PP variables was calculated from multivariable-adjusted Cox regression models. RESULTS: The 11 848 participants from 13 cohorts (age 53 ±â€Š16 years, 50% men) were followed for up for 13.7 ±â€Š6.7 years. A total of 2946 participants died (18.1 per 1000 person-years) and 2093 experienced a fatal or nonfatal cardiovascular event (12.9 per 1000 person-years). Mean PP, elPP, and stPP were, respectively, 49.7, 43.5, and 6.2 mmHg, and elPP and stPP were uncorrelated ( r  = -0.07). At age 50-60 years, all PP variables displayed association with risk for almost all outcomes. From age over 60 years to age over 70 years, hazard ratios of of PP and elPP were similar and decreased gradually but differently for pulse rate lower than or higher than 70 bpm, whereas stPP lacked predictive power in most cases. For age 40 years or less, elPP showed protective power for coronary events, whereas stPP and PP predicted stroke events. Adjusted and unadjusted hazard ratio variations were similar over the entire age range. CONCLUSION: This study provides a new basis for associating PP components with outcome and arterial properties in different age groups and at different pulse rates for both old and young age. The similarity between adjusted and unadjusted hazard ratios supports the clinical usefulness of PP components but further studies are needed to assess the prognostic significance of the PP components, especially at the young age.

Cuffless blood pressure measuring devices: review and statement by the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability.

BACKGROUND: Many cuffless blood pressure (BP) measuring devices are currently on the market claiming that they provide accurate BP measurements. These technologies have considerable potential to improve the awareness, treatment, and management of hypertension. However, recent guidelines by the European Society of Hypertension do not recommend cuffless devices for the diagnosis and management of hypertension. OBJECTIVE: This statement by the European Society of Hypertension Working Group on BP Monitoring and Cardiovascular Variability presents the types of cuffless BP technologies, issues in their validation, and recommendations for clinical practice. STATEMENTS: Cuffless BP monitors constitute a wide and heterogeneous group of novel technologies and devices with different intended uses. Cuffless BP devices have specific accuracy issues, which render the established validation protocols for cuff BP devices inadequate for their validation. In 2014, the Institute of Electrical and Electronics Engineers published a standard for the validation of cuffless BP devices, and the International Organization for Standardization is currently developing another standard. The validation of cuffless devices should address issues related to the need of individual cuff calibration, the stability of measurements post calibration, the ability to track BP changes, and the implementation of machine learning technology. Clinical field investigations may also be considered and issues regarding the clinical implementation of cuffless BP readings should be investigated. CONCLUSION: Cuffless BP devices have considerable potential for changing the diagnosis and management of hypertension. However, fundamental questions regarding their accuracy, performance, and implementation need to be carefully addressed before they can be recommended for clinical use.

Isolated Diastolic Hypertension in the IDACO Study: An Age-Stratified Analysis Using 24-Hour Ambulatory Blood Pressure Measurements.

[Figure: see text].

Home blood pressure monitoring: methodology, clinical relevance and practical application: a 2021 position paper by the Working Group on Blood Pressure Monitoring and Cardiovascular Variability of the European Society of Hypertension.

The present paper provides an update of previous recommendations on Home Blood Pressure Monitoring from the European Society of Hypertension (ESH) Working Group on Blood Pressure Monitoring and Cardiovascular Variability sequentially published in years 2000, 2008 and 2010. This update has taken into account new evidence in this field, including a recent statement by the American Heart association, as well as technological developments, which have occurred over the past 20 years. The present document has been developed by the same ESH Working Group with inputs from an international team of experts, and has been endorsed by the ESH.

May Measurement Month 2019: an analysis of blood pressure screening results from the United Kingdom and Republic of Ireland.

In the UK, heart and circulatory diseases account for 29% of all deaths (14% through coronary heart disease and 8% through stroke). In 2015, the prevalence of hypertension was 20% in the UK and 23% in the Republic of Ireland. In 2019, 14% of people registered with a UK general practice had hypertension and yet it was the attributable risk factor for around half of all deaths from coronary heart disease or stroke. We participated in May Measurement Month 2019 to increase awareness of blood pressure (BP) measurement, and to identify the proportion of undiagnosed hypertension and degree of uncontrolled hypertension in the community. The 2019 campaign set up screening sites within the community at places of worship, supermarkets, GP surgeries, workplaces, charity events, community pharmacies, gyms, and various other public places. We screened 10194 participants (mean age 51 ± 18 years, 60% women) and found that 1013 (9.9%) were on antihypertensive treatment, while 3408 (33.4%) had hypertension. Of the 3408 participants with hypertension, only 33.5% were aware of their condition despite 98.8% having previous BP measurements. In those on antihypertensive medication, only 38.2% had controlled BP (<140 and <90 mmHg). Our UK and Republic of Ireland data demonstrate concerning levels of undiagnosed hypertension and sub-optimal BP control in many individuals with a diagnosis. This evidence supports a critical need for better systematic community and primary care screening initiatives.

Relative and Absolute Risk to Guide the Management of Pulse Pressure, an Age-Related Cardiovascular Risk Factor.

BACKGROUND: Pulse pressure (PP) reflects the age-related stiffening of the central arteries, but no study addressed the management of the PP-related risk over the human lifespan. METHODS: In 4,663 young (18-49 years) and 7,185 older adults (≥50 years), brachial PP was recorded over 24 hours. Total mortality and all major cardiovascular events (MACEs) combined were coprimary endpoints. Cardiovascular death, coronary events, and stroke were secondary endpoints. RESULTS: In young adults (median follow-up, 14.1 years; mean PP, 45.1 mm Hg), greater PP was not associated with absolute risk; the endpoint rates were ≤2.01 per 1,000 person-years. The adjusted hazard ratios expressed per 10-mm Hg PP increments were less than unity (P ≤ 0.027) for MACE (0.67; 95% confidence interval [CI], 0.47-0.96) and cardiovascular death (0.33; 95% CI, 0.11-0.75). In older adults (median follow-up, 13.1 years; mean PP, 52.7 mm Hg), the endpoint rates, expressing absolute risk, ranged from 22.5 to 45.4 per 1,000 person-years and the adjusted hazard ratios, reflecting relative risk, from 1.09 to 1.54 (P < 0.0001). The PP-related relative risks of death, MACE, and stroke decreased >3-fold from age 55 to 75 years, whereas absolute risk rose by a factor 3. CONCLUSIONS: From 50 years onwards, the PP-related relative risk decreases, whereas absolute risk increases. From a lifecourse perspective, young adulthood provides a window of opportunity to manage risk factors and prevent target organ damage as forerunner of premature death and MACE. In older adults, treatment should address absolute risk, thereby extending life in years and quality.

Ambulatory Blood Pressure Monitoring to Diagnose and Manage Hypertension.

This review portrays how ambulatory blood pressure (BP) monitoring was established and recommended as the method of choice for the assessment of BP and for the rational use of antihypertensive drugs. To establish much-needed diagnostic ambulatory BP thresholds, initial statistical approaches evolved into longitudinal studies of patients and populations, which demonstrated that cardiovascular complications are more closely associated with 24-hour and nighttime BP than with office BP. Studies cross-classifying individuals based on ambulatory and office BP thresholds identified white-coat hypertension, an elevated office BP in the presence of ambulatory normotension as a low-risk condition, whereas its counterpart, masked hypertension, carries a hazard almost as high as ambulatory combined with office hypertension. What clinically matters most is the level of the 24-hour and the nighttime BP, while other BP indexes derived from 24-hour ambulatory BP recordings, on top of the 24-hour and nighttime BP level, add little to risk stratification or hypertension management. Ambulatory BP monitoring is cost-effective. Ambulatory and home BP monitoring are complimentary approaches. Their interchangeability provides great versatility in the clinical implementation of out-of-office BP measurement. We are still waiting for evidence from randomized clinical trials to prove that out-of-office BP monitoring is superior to office BP in adjusting antihypertensive drug treatment and in the prevention of cardiovascular complications. A starting research line, the development of a standardized validation protocol for wearable BP monitoring devices, might facilitate the clinical applicability of ambulatory BP monitoring.

Association of Fatal and Nonfatal Cardiovascular Outcomes With 24-Hour Mean Arterial Pressure.

Major adverse cardiovascular events are closely associated with 24-hour blood pressure (BP). We determined outcome-driven thresholds for 24-hour mean arterial pressure (MAP), a BP index estimated by oscillometric devices. We assessed the association of major adverse cardiovascular events with 24-hour MAP, systolic BP (SBP), and diastolic BP (DBP) in a population-based cohort (n=11 596). Statistics included multivariable Cox regression and the generalized R2 statistic to test model fit. Baseline office and 24-hour MAP averaged 97.4 and 90.4 mm Hg. Over 13.6 years (median), 2034 major adverse cardiovascular events occurred. Twenty-four-hour MAP levels of <90 (normotension, n=6183), 90 to <92 (elevated MAP, n=909), 92 to <96 (stage-1 hypertension, n=1544), and ≥96 (stage-2 hypertension, n=2960) mm Hg yielded equivalent 10-year major adverse cardiovascular events risks as office MAP categorized using 2017 American thresholds for office SBP and DBP. Compared with 24-hour MAP normotension, hazard ratios were 0.96 (95% CI, 0.80-1.16), 1.32 (1.15-1.51), and 1.77 (1.59-1.97), for elevated and stage-1 and stage-2 hypertensive MAP. On top of 24-hour MAP, higher 24-hour SBP increased, whereas higher 24-hour DBP attenuated risk (P<0.001). Considering the 24-hour measurements, R2 statistics were similar for SBP (1.34) and MAP (1.28), lower for DBP than for MAP (0.47), and reduced to null, if the base model included SBP and DBP; if the ambulatory BP indexes were dichotomized according to the 2017 American guideline and the proposed 92 mm Hg for MAP, the R2 values were 0.71, 0.89, 0.32, and 0.10, respectively. In conclusion, the clinical application of 24-hour MAP thresholds in conjunction with SBP and DBP refines risk estimates.

Manipulation of Autophagy and Apoptosis Facilitates Intracellular Survival of Staphylococcus aureus in Human Neutrophils.

Polymorphonuclear neutrophils (PMN) are critical for first line innate immune defence against Staphylococcus aureus. Mature circulating PMN maintain a short half-life ending in constitutive apoptotic cell death. This makes them unlikely candidates as a bacterial intracellular niche. However, there is significant evidence to suggest that S. aureus can survive intracellularly within PMN and this contributes to persistence and dissemination during infection. The precise mechanism by which S. aureus parasitizes these cells remains to be established. Herein we propose a novel mechanism by which S. aureus subverts both autophagy and apoptosis in PMN in order to maintain an intracellular survival niche during infection. Intracellular survival of S. aureus within primary human PMN was associated with an accumulation of the autophagic flux markers LC3-II and p62, while inhibition of the autophagy pathway led to a significant reduction in intracellular survival of bacteria. This intracellular survival of S. aureus was coupled with a delay in neutrophil apoptosis as well as increased expression of several anti-apoptotic factors. Importantly, blocking autophagy in infected PMN partially restored levels of apoptosis to that of uninfected PMN, suggesting a connection between the autophagic and apoptotic pathways during intracellular survival. These results provide a novel mechanism for S. aureus intracellular survival and suggest that S. aureus may be subverting crosstalk between the autophagic and apoptosis pathways in order to maintain an intracellular niche within human PMN.

Pro-inflammatory Stimulation of Monocytes by ANCA Is Linked to Changes in Cellular Metabolism.

Clinical and experimental data suggest that pathogenesis in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is driven by ANCA-mediated activation of neutrophils and monocytes. While the role of neutrophils has been extensively investigated, the function of monocytes remains relatively understudied. We have previously demonstrated that stimulation of monocytes with anti-myeloperoxidase (MPO), but not anti-proteinase-3 (PR3), antibodies results in production of the pro-inflammatory cytokine IL-1ß. Changes in cellular metabolism, particularly a switch to glycolysis, have recently been linked to activation of immune cells and production of IL-1ß. Therefore, we investigated the metabolic profile of monocytes following ANCA stimulation. We found a significant increase in glucose uptake in anti-MPO stimulated monocytes. Interestingly, both anti-MPO and anti-PR3 stimulation resulted in an immediate increase in glycolysis, measured by Seahorse extracellular flux analysis. However, this increase in glycolysis was sustained (for up to 4 h) in anti-MPO- but not anti-PR3-treated cells. In addition, only anti-MPO-treated cells exhibited increased oxidative phosphorylation, a metabolic response that correlated with IL-1ß production. These data indicate that monocyte metabolism is altered by ANCA, with divergent responses to anti-MPO and anti-PR3 antibodies. These metabolic changes may underlie pathologic immune activation in ANCA associated vasculitis, as well as potentially contributing to the differing clinical phenotype between PR3- and MPO-ANCA positive patients. These metabolic pathways may therefore be potential targets for therapeutic intervention.

May Measurement Month 2018: an analysis of blood pressure screening results from the UK and the Republic of Ireland.

Raised blood pressure (BP) was the biggest contributor to the global burden of disease in 2017, with lack of awareness and adequate control of BP identified as the main drivers of this disease burden. In 2017, an opportunistic BP screening and awareness campaign called May Measurement Month (MMM) in the UK and Republic of Ireland (RoI) highlighted that levels of undiagnosed hypertension and uncontrolled hypertension in the community screened were approximately 23% and 40%, respectively. MMM18 was undertaken to further the campaign's efforts to increase awareness and create an evidence base of population risk associated with high BP. MMM18 BP screenings were conducted in the community at places of worship, supermarkets, GP surgeries, workplaces, community pharmacies, gyms, and various other public places. A total of 5000 volunteers, aged 47.3 (±17.2) years, 60% female were screened. Of all 5000 individuals screened, 1716 (34.3%) were hypertensive, of which only 51.3% were aware of their condition, 42.8% on antihypertensive treatment, and only 51.5% of those on medication controlled to target BP of <140/90 mmHg. Furthermore, obese, overweight, and underweight participants all had significantly higher BP values compared to individuals with a healthy body mass index (BMI). The 2018 MMM campaign in the UK and the RoI confirmed approximately one in three adults were hypertensive, with more than half having uncontrolled BP. In addition, these findings show that people with low BMI are at risk of having high BP. Finally, with only one in two people aware of their high BP, awareness remains a significant public health concern.

A novel concept: cardiovascular assessment of hypertensive patients in pharmacies.

A range of cardiovascular investigations is required for the effective management of hypertension. To obtain these investigations my require the patient having to attend many facilities. A scheme for performing basic cardiovascular investigations in pharmacies is proposed.