Chick PTPσ regulates the targeting of retinal axons within the optic tectum

Chick PTP (cPTP), also known as CRYP, is a receptor-like protein tyrosine phosphatase found on axons and growth cones. Putative ligands for cPTP are distributed within basement membranes and on glial end feet of the retina, optic nerve, and optic tectum, suggesting that cPTP signaling is occurring along the whole retinotectal pathway. We have shown previously that cPTP plays a role in supporting the retinal phase of axon outgrowth. Here we have now addressed the role of cPTP within retinal axons as they undergo growth and topographic targeting in the optic tectum. With the use of retroviruses, a secretable cPTP ectodomain was ectopically expressed in ovo in the developing chick optic tectum, with the aim of directly disrupting the function of endogenous cPTP. In ovo, the secreted ectodomains accumulated at tectal sites in which cPTP ligands are also specifically found, suggesting that they are binding to these endogenous ligands. Anterograde labeling of retinal axons entering these optic tecta revealed abnormal axonal phenotypes. These included the premature stalling and arborization of fibers,excessive pretectal arbor formation, and diffuse termination zones. Most of the defects were rostral of the predicted termination zone, indicating that cPTP function is necessary for sustaining the growth of retinal axons over the optic tectum and for directing axons to their correct sites of termination. This demonstrates that regulation of cPTP signaling in retinal axons is required for their topographic mapping, the first evidence of this function for a receptor-like protein tyrosine phosphatase in the retinotectal projection

Pericardial effusion with cystic mass

Patient with a 2-month history of exertional dyspnoea and a non-productive cough

Patient profi le of a tertiary obstetric-cardiac clinic

Background: Cardiac disease is the most important medical cause of maternal mortality in South Africa. Management of women with cardiac disease in pregnancy is highly specialised and they should ideally be evaluated early in pregnancy and in a multidisciplinary fashion with the aim of formulating a perinatal management plan. In order to facilitate the effi cient management of these patients in the context of a large tertiary hospital in South Africa a combined obstetric-cardiac (O-C) clinic was established at Tygerberg Academic Hospital (TBH) in 2010. Objective: The purpose of this review is to describe the patient profi le of an obstetric-cardiac clinic in South Africa, specifi cally the TBH O-C clinic and to share thelessons learnt from establishing this clinic. Methods: Retrospective review performed at TBH, a referral centre in the Western Cape Province of SouthAfrica. All women evaluated and/or managed at the Obstetric-Cardiac clinic between 10 August 2010 and 4 December 2012 were included. Results: There were 231 women, rheumatic heart disease (n=79; 34.2%) was the predominant cardiac disease followed by congenital heart disease (n=78; 33.8%), medical conditions (n=38; 16.4%) and previous peripartum cardiomyopathy (n=9; 3.9%). Eighty-two women (35.5%) were perceived to be extremely high risk and their entire pregnancies were managed in the Obstetric-Cardiac clinic. The most common RHD lesion was mitral regurgitation (34.2%) and mixed mitral valve disease (24.1%). The most frequent CHD was ventricular septal defects (n=27; 35%). Conclusions: The cardiac disease profi le of patients seen at this obstetric-cardiac clinic in a South African tertiary hospital refl ects a transition from the disease profi le of a typical developing country (high burden of rheumatic heart disease) to the disease profi le seen in a more developed country (high burden of congenital heart disease). This could indicate improved quality of socio-economic development and the health care system. The increasing complexity of cardiac pathology that has to be dealt with in pregnant patients presenting to a tertiary hospital requires close collaboration between the obstetrician, cardiologist, cardiac surgeon and anesthetist caring for these patients. A dedicated obstetric-cardiac clinic is a good model to utilise in a tertiary hospital when aiming to optimise the care of patients with cardiac disease in pregnancy

Evaluating the time interval from diagnosis to fibrinolysis at centres in the drainage area of Tygerberg Hospital, Cape Town, South Africa

Background. ST-segment elevation myocardial infarction (STEMI) is one of the main contributors to morbidity and mortality in South Africa (SA). Timeous intervention by means of percutaneous coronary intervention (PCI) or fibrinolysis can significantly improve the outcome of STEMI.Objectives. To determine the median time interval between diagnosis and fibrinolysis in patients presenting to centres within the drainage area of Tygerberg Hospital, Cape Town, SA, and compare it with the European Society of Cardiology (ESC) recommendation of 10 minutes.Methods. A retrospective medical record review of patients presenting to the abovementioned centres between 1 March 2017 and 28 February 2018 was performed. The primary presenting centre, time between diagnosis and fibrinolysis and discharge medication were recorded, in addition to other relevant demographic information.Results. A total of 492 patients were identified, of whom 447 were included in the study. Three hundred and eighteen patients received fibrinolysis, of whom 18 (5.7%) were treated within 10 minutes of diagnosis. The median time interval between diagnosis and fibrinolysis was 67 (interquartile range (IQR) 32.5 -122.5) minutes.Conclusions. Most patients received fibrinolysis >10 minutes after diagnosis, which indicates suboptimal therapy when compared with the ESC guidelines. Future studies should investigate the factors prolonging this therapeutic delay

Zoonotic Endocarditis: Is the feather mightier than the sword?

The common causes of infective endocarditis (IE) in South Africa are Staphylococcus aureus, the viridans streptococci and Bartonella species. Infection with Erysipelothrix rhusiopathiae is a rare cause of IE that is usually associated with occupational exposure and can be acquired from humans and animals. It was fi rst reported in 1912 by Gunthar, and thereafter fewer than 60 cases have been reported. We describe a case of Erysipelothrix rhusiopathiae induced endocarditis in Cape Town, South Africa. S SAHeart 2022;19:24-2

Predictors of 1-year survival in South African transcatheter aortic valve implant candidates

Background. Transcatheter aortic valve implantation (TAVI) has undergone rapid expansion internationally over the past 15 years. In view of resource constraints in developing countries, a major challenge in applying this technology lies in identifying patients most likely to benefit. The development of a risk prediction model for TAVI has proved elusive, with a reported area under the curve (AUC) of 0.6 - 0.65. The available models were developed in a First-World setting and may not be applicable to South Africa (SA).Objectives. To evaluate novel indicators and to develop a TAVI risk prediction model unique to the SA context. The current work represents the important initial steps of derivation cohort risk model development and internal validation.Methods. Seven-year experience with 244 successive TAVI implants in three centres in Western Cape Province, SA, was used to derive risk parameters. All outcomes are reported in accordance with the Valve Academic Research Consortium definitions. Multiple preprocedural variables were assessed for their impact on 1-year survival using univariate and multivariate models.Results. Factors found not to correlate with 1-year survival included age, renal function and aortic valve gradients. The commonly used surgical risk prediction models (Society of Thoracic Surgeons score and EuroSCORE) showed no correlation with outcomes. Factors found to correlate best with 1-year survival on multivariate analysis were preprocedural body mass index (BMI) (favouring higher BMI), preprocedural left ventricular end-diastolic dimension (LVED) and ejection fraction (EF) (favouring smaller LVED and higher EF), absence of atrial fibrillation, and three novel parameters: independent living, ability to drive a car, and independent food acquisition/cooking. Discriminant analysis of these factors yielded an AUC of 0.8 (95% confidence interval 0.7 - 0.9) to predict 1-year survival, with resubstitution sensitivities and specificities of 72% and 71%, respectively.Conclusions. Apart from existing predictors, we identified three novel risk predictors (independent living, ability to drive a car, and independent food acquisition/cooking) for 1-year survival in TAVI candidates. These novel parameters performed well in this early evaluation, with an AUC for predicting 1-year survival higher than the AUCs for many of the internationally derived parameters. The parameters are inexpensive and easy to obtain at the initial patient visit. If validated prospectively in external cohorts, they may be applicable to other resource-constrained environments.

Postpulmonary tuberculosis complications in South Africa and a potential link with pulmonary hypertension: Premise for clinical and scientific investigations

CITATION: Allwood, B. W. et al. 2018. Post-pulmonary tuberculosis complications in South Africa and a potential link with pulmonary hypertension : premise for clinical and scientific investigations. South African Medical Journal, 108(7):529, doi:10.7196/SAMJ.2018.v108i7.13359.The original publication is available at http://www.samj.org.zaThe magnitude of the pulmonary tuberculosis (TB) epidemic in South Africa (SA) and globally[1] has received increased attention. Efforts have been made to explore new and improved diagnostic[2] and treatment strategies,[3] but the story does not end with treatment, and TB frequently results in long-term lung damage.http://www.samj.org.za/index.php/samj/article/view/12339/8528Publisher's versio