Hypertension, chronic kidney disease, atrial fibrillation and the newer anticoagulants

Atrial fibrillation (AF) is a common clinical condition that is associated with increased morbidity and mortality that mainly relates to an embolic stroke. Dominant risk factors for AF are advanced age and hypertension in the absence of mitral valve disease.1 In turn, hypertension and ageing are determinants of the congestive heart failure, hypertension, age, diabetes mellitus, prior stroke or transient ischaemic attack or thromboembolism (CHADS2) criteria for assessing the indication for anticoagulation. In addition, they are important risk factors for chronic kidney disease (CKD). In itself, CKD is an independent risk factor for AF and a higher risk of stroke.2 It is highly likely that a practitioner will encounter older patients with AF and concomitant hypertension and CKD that require anticoagulation therapy. Thus, it is essential for the practitioner to understand the risks and benefits of anticoagulation in older patients with AF, hypertension and CKD

The abridged South African hypertension guideline 2011

Extensive data from randomised controlled trials have shown the benefit of treating hypertension. The target blood pressure (BP) for antihypertensive management is < 140/90 mmHg, and < 130/80 mmHg in patients with end-organ damage, coexisting risk factors, and co-morbidity. Benefits of management include reduced risk of death, stroke, cardiac failure, chronic kidney disease, and coronary heart disease. The correct BP measurement procedure is described, and evaluation of cardiovascular risk factors and recommendations for antihypertensive therapy, are stipulated. Lifestyle modification and patient education are cornerstones in the management of every patient. Major indications, precautions, and contraindications to each recommended antihypertensive drug are listed. Combination therapy should be considered ab initio if the BP is ≥ 20/10 mmHg above goal. First-line drug therapy for uncomplicated essential hypertension includes low-dose thiazide-like diuretics, calcium-channel blockers, angiotensin-converting enzyme inhibitors, or angiotensin-receptor blockers. The guideline was developed by the Southern African Hypertension Society

Inoculation of peritoneal dialysate fluid into blood culture bottles improves culture rates

The aim of he study was to determine if direct inoculation of peritoneal fluid into Bactec blood culture bottles would improve the positive bacteriological yield compared with conventional techniques in continuous ambulatory peritoneal dialysis (CAPD) patients with peritonitis. All patients presenting with suspected peritonitis had peritoneal fluid injected directly into aerobic and anaerobic Bactec blood culture bottles as well as into sterile culture tubes. Thirty-seven paired samples were analyzed.The aim of he study was to determine if direct inoculation of peritoneal fluid into Bactec blood culture bottles would improve the positive bacteriological yield compared with conventional techniques in continuous ambulatory peritoneal dialysis (CAPD) patients with peritonitis. All patients presenting with suspected peritonitis had peritoneal fluid injected directly into aerobic and anaerobic Bactec blood culture bottles as well as into sterile culture tubes. Thirty-seven paired samples were analyzed

Inoculation of peritoneal dialysate fluid into blood culture bottles improves culture rates

The aim of the study was to determine if direct inoculation of peritoneal fluid into Bactec blood culture bottles would improve the positive bacteriological yield compared with conventional techniques in continuous ambulatory peritoneal dialysis (CAPD) patients with peritonitis. All patients presenting with suspected peritonitis had peritoneal fluid injected directly into aerobic and anaerobic Bactec blood culture bottles as well as into sterile culture tubes. Thirty-seven paired samples were analysed. Twenty conventional cultures (54%) were positive compared with 33 (89%) done according to the Bactec system (P &lt; 0,002). In only 1 case did the former technique prove superior. Direct inoculation of peritoneal fluid into Bactec blood culture bottles is therefore superior to conventional methods and has obvious therapeutic implications

Towards characterizing LNAPL remediation endpoints

Remediating sites contaminated with light non-aqueous phase liquids (LNAPLs) is a demanding and often prolonged task. It is vital to determine when it is appropriate to cease engineered remedial efforts based on the long-term effectiveness of remediation technology options. For the first time, the long term effectiveness of a range of LNAPL remediation approaches including skimming and vacuum-enhanced skimming each with and without water table drawdown was simulated through a multi-phase and multi-component approach. LNAPL components of gasoline were simulated to show how component changes affect the LNAPL\u27s multi-phase behaviour and to inform the risk profile of the LNAPL. The four remediation approaches along with five types of soils, two states of the LNAPL specific mass and finite and infinite LNAPL plumes resulted in 80 simulation scenarios. Effective conservative mass removal endpoints for all the simulations were determined. As a key driver of risk, the persistence and mass removal of benzene was investigated across the scenarios. The time to effectively achieve a technology endpoint varied from 2 to 6 years. The recovered LNAPL in the liquid phase varied from 5% to 53% of the initial mass. The recovered LNAPL mass as extracted vapour was also quantified. Additional mass loss through induced biodegradation was not determined. Across numerous field conditions and release incidents, graphical outcomes provide conservative (i.e. more prolonged or greater mass recovery potential) LNAPL remediation endpoints for use in discussing the halting or continuance of engineered remedial efforts

Towards a digital twin for characterising natural source zone depletion: A feasibility study based on the Bemidji site

Natural source zone depletion (NSZD) of light non-aqueous phase liquids (LNAPLs) may be a valid long-term management option at petroleum impacted sites. However, its future long-term reliability needs to be established. NSZD includes partitioning, biotic and abiotic degradation of LNAPL components plus multiphase fluid dynamics in the subsurface. Over time, LNAPL components are depleted and those partitioning to various phases change, as do those available for biodegradation. To accommodate these processes and predict trends and NSZD over decades to centuries, for the first time, we incorporated a multi-phase multi-component multi-microbe non-isothermal approach to representatively simulate NSZD at field scale. To validate the approach we successfully mimic data from the LNAPL release at the Bemidji site. We simulate the entire depth of saturated and unsaturated zones over the 27 years of post-release measurements. The study progresses the idea of creating a generic digital twin of NSZD processes and future trends. Outcomes show the feasibility and affordability of such detailed computational approaches to improve decision-making for site management and restoration strategies. The study provided a basis to progress a computational digital twin for complex subsurface systems

Quantifying the benefits of in-time and in-place responses to remediate acute LNAPL release incidents

Acute large volume spills from storage tanks of petroleum hydrocarbons as light non aqueous phase liquids (LNAPLs) can contaminate soil and groundwater and may have the potential to pose explosive and other risks. In consideration of an acute LNAPL release scenario, we explore the value of a rapid remediation response, and the value of installing remediation infrastructure in close proximity to the spill location, in effecting greater recovery of LNAPL mass from the subsurface. For the first time, a verified three-dimensional multi-phase numerical framework and supercomputing resources was applied to explore the significance of in-time and in-place remediation actions. A sand aquifer, two release volumes and a low viscosity LNAPL were considered in key scenarios. The time of commencement of LNAPL remediation activities and the location of recovery wells were assessed requiring asymmetric computational considerations. The volume of LNAPL released considerably affected the depth of LNAPL penetration below the groundwater table, the radius of the plume over time and the recoverable LNAPL mass. The remediation efficiency was almost linearly correlated with the commencement time, but was a non-linear function of the distance of an extraction well from the spill release point. The ratio of the recovered LNAPL in a well located at the centre of the spill/release compared to a well located 5 m away was more than 3.5, for recovery starting only 7 days after the release. Early commencement of remediation with a recovery well located at the centre of the plume was estimated to recover 190 times more LNAPL mass than a one-month delayed commencement through a well 15 m away from the centre of the LNAPL plume. Optimally, nearly 40% of the initially released LNAPL could be recovered within two months of commencing LNAPL recovery actions

Registration of amiloride in South Africa: Cutting the Gordian knot

Amiloride is an antagonist of the renal tubular epithelial sodium channel (ENaC). As such, it is a diuretic that is both potassium and magnesium sparing. It is used for the treatment of potassium depletion and hypertension, and is the specific therapy for hypertension due to overactivity of the ENaC (Liddle syndrome and several additional genetic causes of the Liddle phenotype - low renin and low aldosterone). It is listed as a World Health Organization essential drug, but has never been registered in South Africa (SA) and can therefore only be prescribed under a Section 21 application to the SA Health Products Regulatory Authority (SAHPRA) on a case-by-case basis. In SA, \u3e50% of patients treated for hypertension are not controlled. In the USA, the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study reported that African Americans are more likely to be diagnosed with hypertension, more likely to be treated, more likely to be treated intensively, and less likely to achieve blood pressure (BP) control. Although the reasons are complex, studies show that 10 - 20% of blacks may carry the Liddle phenotype. Observational data and a controlled clinical trial done in three African countries have shown that these patients respond to amiloride and not to conventional guideline-based antihypertensive treatment. The former is likely to result in a significant reduction in cardiovascular, stroke and kidney morbidity and mortality, because of improved BP control. Amiloride is very unlikely to ever be registered in SA, as it was first developed \u3e50 years ago, and SAHPRA regulations prevent widespread prescription of this essential drug. This is a classic Gordian knot that requires a novel approach from authorities to sever the knot and improve the health of many South Africans

Realization of an Inductance Scale Traceable to the Quantum Hall Effect Using an Automated Synchronous Sampling System

In this paper, the realization of an inductance scale from 1~$\mu$H to 10~H for frequencies ranging between 50~Hz to 20~kHz is presented. The scale is realized directly from a series of resistance standards using a fully automated synchronous sampling system. A careful systematic characterization of the system shows that the lowest uncertainties, around 12~$\mu$H/H, are obtained for inductances in the range from 10~mH to 100~mH at frequencies in the kHz range. This new measurement system which was successfully evaluated during an international comparison, provides a primary realization of the henry, directly traceable to the quantum Hall effect. An additional key feature of this system is its versatility. In addition to resistance-inductance (R-L) comparison, any kind of impedances can be compared: R-R, R-C, L-L or C-C, giving this sampling system a great potential of use in many laboratories around the world