The Importance of Awareness and Education in Prevention and Control of RHD

AbstractAcute rheumatic fever and rheumatic heart disease are diseases of poverty, low socioeconomic status, and inadequate access to health care. These preventable diseases remain largely ignored by the developed world while they continue to cause significant mortality and morbidity in the developing world. In the face of no existing cure, we need to focus on prevention and control methods. To this end, creating awareness of the disease and its effects on millions of people in the world is critically important. In this review, we will outline the importance of these efforts, discuss the barriers to awareness and education, and highlight some important models in this arena. We strongly support awareness-raising and health promotion strategies as an integral part of a rheumatic heart disease prevention and control program

Primary Prevention for Rheumatic Fever Progress, Obstacles, and Opportunities

ABSTRACT Acute rheumatic fever and rheumatic heart disease are noninfectious sequelae of group A streptococcal pharyngeal infection. These diseases represent a huge public health burden in developing countries with significant mortality and morbidity. Early diagnosis and appropriate antibiotic treatment with group A streptococcal pharyngitis provides an opportunity for prevention of acute rheumatic fever and rheumatic heart disease. The use of locally adapted clinical algorithms for diagnosing group A streptococcal pharyngitis has great potential in resource-poor settings for earlier diagnosis and early treatment. Intramuscular penicillin is the drug of choice in developing country settings. Recent work has demonstrated the cost-effectiveness of a treat-all strategy with intramuscular penicillin, whereas incorporating a clinical decision rule remains the preferred strategy. We strongly support the adoption of a comprehensive prevention and control program for acute rheumatic fever and rheumatic heart disease, incorporating primary prevention, as critical to underpinning the efforts in many parts of the world to stem the tide of this devastating disease. Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) continue to kill children, adolescents, and young adults living in poverty. Yet, a cheap and effective preventative agent to these sequelae of group A streptococcal (GAS) infection has existed for decades in the form of penicillin. Despite strong evidence of penicillin's efficacy in primary prevention of ARF, debate still rages on regarding the appropriate role for primary prevention within RHD prevention and control strategies. Some of the arguments against the incorporation of primary prevention into RF/RHD control strategies are based on the expense and logistics of delivery, but as has been discussed elsewhere [1], these need not be limiting factors. Conversely, a recent publication has demonstrated the cost-effectiveness of such a strateg

The burden of cardiovascular disease in sub-Saharan Africa

Correspondence: The burden of cardiovascular disease in sub-Saharan Africa by Anthony Mbewu

A Survey of Chloroplast Protein Kinases and Phosphatases in Arabidopsis thaliana

Protein phosphorylation is a major mode of regulation of metabolism, gene expression and cell architecture. In chloroplasts, reversible phosphorylation of proteins is known to regulate a number of prominent processes, for instance photosynthesis, gene expression and starch metabolism. The complements of the involved chloroplast protein kinases (cpPKs) and phosphatases (cpPPs) are largely unknown, except 6 proteins (4 cpPKs and 2 cpPPs) which have been experimentally identified so far. We employed combinations of programs predicting N-terminal chloroplast transit peptides (cTPs) to identify 45 tentative cpPKs and 21 tentative cpPPs. However, test sets of 9 tentative cpPKs and 13 tentative cpPPs contain only 2 and 7 genuine cpPKs and cpPPs, respectively, based on experimental subcellular localization of their N-termini fused to the reporter protein RFP. Taken together, the set of enzymes known to be involved in the reversible phosphorylation of chloroplast proteins in A. thaliana comprises altogether now 6 cpPKs and 9 cpPPs, the function of which needs to be determined in future by functional genomics approaches. This includes the calcium-regulated PK CIPK13 which we found to be located in the chloroplast, indicating that calcium-dependent signal transduction pathways also operate in this organelle

Pediatric systemic lupus erythematosus patients in South Africa have high prevalence and severity of cardiac and vascular manifestations

Abstract Background Pediatric onset of systemic lupus erythematosus (SLE) is associated with major organ involvement, and African patients tend to develop more aggressive disease than patients of European descent. Although cardiovascular involvement is common in pediatric SLE, there are few published reports on the subject. This study describes the frequency and characteristics of cardiac and vascular manifestations of pediatric SLE in a multi-ethnic South African cohort. Methods Demographic, clinical, and echocardiographic data were collected from pediatric SLE patients at two centers in Cape Town, South Africa. At the time of investigation, this cohort consisted of 93 participants diagnosed with SLE according to international classification criteria prior to the age of 19. Individuals with cardiac and/or vascular involvement were identified by retrospective chart review. Cardiac manifestations were defined as presence of pericardial effusion, myocarditis, cardiomyopathy, cardiac failure, Libman-Sacks endocarditis, myocardial infarction, and arrhythmia. Vascular manifestations included deep vein thrombosis, pulmonary embolism, sinus thrombosis, stroke, critical limb ischemia, cerebral vasculitis and systemic vasculitis. Statistical analysis was performed using R (v3.4.1). Results Cardiac and vascular involvement was present in 47% of the cohort. Previous studies have reported prevalence of 5%—50%. Demographic features of those with cardiac/vascular involvement did not differ from the overall cohort. Echocardiographic data were available for 23 participants. The most common cardiac manifestations were pericardial effusion (n = 24) and cardiac failure (n = 8), while the most common vascular manifestations were cerebral vasculitis (n = 9), stroke (n = 7), and pulmonary embolism (n = 7). Cardiovascular manifestations were frequently severe; one third of pericardial effusion cases required intervention, including three cases of cardiac tamponade. Cardiac and vascular involvement conferred an increased risk of mortality (31.1% versus 10.4%). Conclusions Cardiac and vascular involvement were highly prevalent in this South African cohort. The mortality rate was high, and severe manifestations were frequent. Prospective research is needed to improve knowledge of pediatric SLE in Africa and to improve outcomes for this high-risk population

Safety of streptococcus pyogenes vaccines: anticipating and overcoming challenges for clinical trials and post marketing monitoring

Streptococcus. pyogenes (Strep A) infections result in a vastly underestimated burden of acute and chronic disease globally. The Strep A Vaccine Global Consortium (SAVAC) mission is to accelerate the development of safe, effective and affordable S. pyogenes vaccines. The safety of vaccine recipients is of paramount importance. A single S. pyogenes vaccine clinical trial conducted in the 1960s raised important safety concerns. A SAVAC Safety Working Group was established to review the safety assessment methodology and results of more recent early phase clinical trials and to consider future challenges for vaccine safety assessments across all phases of vaccine development. No clinical or biological safety signals were detected in any of these early phase trials in the modern era. Improvements in vaccine safety assessments need further consideration, particularly for pediatric clinical trials, large-scale efficacy trials, and preparation for post-marketing pharmacovigilance

Spectrum of cardiac disease in maternity in a low-resource cohort in South Africa

Background: Lack of evidence-based data on the spectrum of cardiovascular disease (CVD) in pregnancy or in the postpartum period, as well as on maternal and fetal outcome, provides challenges for treating physicians, particularly in areas of low resources. The objectives of this study were to investigate the spectrum of disease, mode of presentation and maternal and fetal outcome of patients referred to a dedicated Cardiac Disease and Maternity Clinic (CDM). Methods: The prospective cohort study was conducted at a single tertiary care centre in South Africa. Two hundred and twenty-five women presenting with CVD in pregnancy, or within 6 months postpartum, were studied over a period of 2 years. Clinical assessment, echocardiography and laboratory tests were performed at baseline and follow-up visits. Prepartum, peripartum and postpartum complications were grouped into cardiac, neonatal and obstetric events. Results: Ethnicity was black African (45%), mixed ethnicity (32%), white (15%), Indian/others (8%) and 12% were HIV positive. Of the 225 consecutive women (mean age 28.8±6.4), 196 (86.7%) presented prepartum and 73 in modified WHO class I. The 152 women presenting in a higher risk group (modified WHO class II-IV) were offered close follow-up at the CDM clinic and were diagnosed with congenital heart disease (32%, 15 operated previously), valvular heart disease (26%, 15 operated previously), cardiomyopathy (27%) and other (15%). Women presenting with symptoms of CVD or heart failure postpartum (n=30) presented in a higher New York Heart Association, had higher heart rates (p42 days postpartum. Perinatal death occurred in 1/152 (0.7%) - translating to a perinatal mortality rate of 7/1000 live births. Conclusions: Disease patterns were markedly different to that seen in the developed world. However, joint obstetric-cardiac care in the low-resource cohort was associated with excellent survival outcome rates of pregnant mothers (even with complex diseases) and their offspring and was similar to that seen in the western world. Mortality typically occurred in the postpartum period, beyond the standard date of recording maternal death

Cyclin-dependent kinase 18 controls trafficking of aquaporin-2 and its abundance through ubiquitin ligase STUB1, which functions as an AKAP

Arginine-vasopressin (AVP) facilitates water reabsorption in renal collecting duct principal cells through regulation of the water channel aquaporin-2 (AQP2). The hormone binds to vasopressin V2 receptors (V2R) on the surface of the cells and stimulates cAMP synthesis. The cAMP activates protein kinase A (PKA), which initiates signaling that causes an accumulation of AQP2 in the plasma membrane of the cells facilitating water reabsorption from primary urine and fine-tuning of body water homeostasis. AVP-mediated PKA activation also causes an increase in the AQP2 protein abundance through a mechanism that involves dephosphorylation of AQP2 at serine 261 and a decrease in its poly-ubiquitination. However, the signaling downstream of PKA that controls the localization and abundance of AQP2 is incompletely understood. We carried out an siRNA screen targeting 719 kinase-related genes, representing the majority of the kinases of the human genome and analyzed the effect of the knockdown on AQP2 by high-content imaging and biochemical approaches. The screening identified 13 hits whose knockdown inhibited the AQP2 accumulation in the plasma membrane. Amongst the candidates was the so far hardly characterized cyclin-dependent kinase 18 (CDK18). Our further analysis revealed a hitherto unrecognized signalosome comprising CDK18, an E3 ubiquitin ligase, STUB1 (CHIP), PKA and AQP2 that controls the localization and abundance of AQP2. CDK18 controls AQP2 through phosphorylation at serine 261 and STUB1-mediated ubiquitination. STUB1 functions as an A-kinase anchoring protein (AKAP) tethering PKA to the protein complex and bridging AQP2 and CDK18. The modulation of the protein complex may lead to novel concepts for the treatment of disorders which are caused or are associated with dysregulated AQP2 and for which a satisfactory treatment is not available, e.g., hyponatremia, liver cirrhosis, diabetes insipidus, ADPKD or heart failure

An AKAP-Lbc-RhoA interaction inhibitor promotes the translocation of aquaporin-2 to the plasma membrane of renal collecting duct principal cells

Stimulation of renal collecting duct principal cells with antidiuretic hormone (arginine-vasopressin, AVP) results in inhibition of the small GTPase RhoA and the enrichment of the water channel aquaporin-2 (AQP2) in the plasma membrane. The membrane insertion facilitates water reabsorption from primary urine and fine-tuning of body water homeostasis. Rho guanine nucleotide exchange factors (GEFs) interact with RhoA, catalyze the exchange of GDP for GTP and thereby activate the GTPase. However, GEFs involved in the control of AQP2 in renal principal cells are unknown. The A-kinase anchoring protein, AKAP-Lbc, possesses GEF activity, specifically activates RhoA, and is expressed in primary renal inner medullary collecting duct principal (IMCD) cells. Through screening of 18,431 small molecules and synthesis of a focused library around one of the hits, we identified an inhibitor of the interaction of AKAP-Lbc and RhoA. This molecule, Scaff10-8, bound to RhoA, inhibited the AKAP-Lbc-mediated RhoA activation but did not interfere with RhoA activation through other GEFs or activities of other members of the Rho family of small GTPases, Rac1 and Cdc42. Scaff10-8 promoted the redistribution of AQP2 from intracellular vesicles to the periphery of IMCD cells. Thus, our data demonstrate an involvement of AKAP-Lbc-mediated RhoA activation in the control of AQP2 trafficking