Serum brain natriuretic peptide (BNP) and N-terminal brain natriuretic peptide (NT-proBNP) in heart valve disease

Serum levels of natriuretic peptides (BNP and NT- proBNP) are known to increase in cardiac failure, and aid in the diagnosis and management of such patients. BNP and NT-proBNP also increase in patients with heart valve lesions, and may contribute to the assessment and management of these patients. There appears to be a general trend towards higher BNP values in more severe heart valve lesions, but the exact implication of a raised BNP or NTproBNP appears to be different for each specific valve lesion. In aortic valve stenosis increased levels of BNP/NT-proBNP correlate with the degree of stenosis, symptoms and prognosis. In addition, the increased natriuretic peptide levels seem to reflect left ventricular dysfunction, as high levels predict poor long-term outcomes in conservatively treated patients as well as post-operative death and poor functional recovery in those who survive the valve replacement procedure. In mitral regurgitation natriuretic peptide levels correlate with the degree of valvular regurgitation, and seem to reflect subclinical left ventricular dysfunction. Serum natriuretic peptide levels are elevated in patients with mitral stenosis, and correlate with the degree of valvular stenosis and increased pulmonary pressure. Serum levels of natriuretic peptides are elevated in other heart valve lesions, such as aortic valve regurgitation, as well as different forms of mixed valvular disease, but very little is known about the relationship between the serum levels of natriuretic peptides and the latter valve lesions. The practical application of our knowledge concerning serum natriuretic peptides and heart valve disease is limited at this stage, and no specific cut-off values to guide patient management have been incorporated into any official guidelines as yet. This review aims to summarise current knowledge on serum BNP and NT–proBNP levels in patients with heart valve disease. The impact of this information on current clinical decision making in patients with different heart valve lesions, as well as evolving concepts concerning its potential future use, will be discussed

Assessing prior learning in English Business Communication at a South African university of technology

n.a

The prevalence of burnout and depression in medical doctors working in the Cape Town Metropolitan Municipality community healthcare clinics and district hospitals of the Provincial Government of the Western Cape: a cross-sectional study

Aim: This study investigated burnout and depression in medical doctors in the context of work-related conditions and the role of resilience as a modifiable factor.Method: A cross-sectional, observational study was conducted on consenting medical doctors (n = 132) working at Cape Town Metropolitan Municipality primary healthcare facilities of the Provincial Government of the Western Cape. Data were collected from doctors at 27 facilities by means of a self-administered questionnaire battery, containing socio-demographic information, the Beck Depression Inventory (BDI), the Maslach Burnout Inventory (MBI) and the Connor-Davidson Resilience Scale (CD-RISC).Results: Of 132 doctors included in the analysis, 76% experienced burnout, as indicated by high scores in either the emotional exhaustion or depersonalisation subscales. In addition, 27% of doctors had cut-off scores on the BDI indicating moderate depression, while 3% were identified to have severe depression. The number of hours, work load, working conditions and system-related frustrations were ranked as the most important contributing factors to burnout. More experienced doctors and those with higher resilience scores had lower levels of burnout, as evident by their lower scores in the emotional exhaustion and depersonalisation domains of the MBI.Conclusion: Both burnout and depression are prevalent problems in doctors working at district level and in communities. Resilience appears to be protective and may be a useful target for future intervention.Keywords: depression, burnout, stress, physician, medical docto

Sudden and unexpected childhood deaths investigated at the Pretoria Medico-Legal Laboratory, South Africa, 2007 - 2011

Background. Sudden and unexpected death is well known to occur in infants, and although sudden deaths are less frequent after the first birthday, they still account for a significant proportion of childhood deaths. In 2009, 1.9% of the total deaths in the USA were childhood deaths. In South Africa (SA) this proportion was much higher at 11.85%. According to the law, sudden and unexpected deaths are generally investigated as unnatural deaths. Establishing an exact underlying anatomical cause of death will depend on available resources and can be difficult in a substantial proportion of cases.Methods. A retrospective descriptive case audit was conducted at the Pretoria Medico-Legal Laboratory (PMLL), SA, from 1 January 2007 through to 31 December 2011. All children aged 1 - 18 years who died suddenly and unexpectedly were included.Results. Ninety-eight cases were identified, which constituted nearly 1% of total admissions to the PMLL. The majority of the deaths were of children aged 1 - 5 years, and the male/female ratio was 1.04:1. In the largest proportion of cases (n=28, 28.6%), the medicolegal investigation, including autopsy and ancillary investigations, did not establish an underlying anatomical cause of death. In the cases where a cause of death was established, pneumonia was the most common diagnosis (n=22, 22.4%).Conclusions. The fact that the cause of the largest proportion of deaths could not be ascertained emphasises the need for consideration of additional investigative techniques, such as molecular/genetic screening, which have provided an underlying cause of death in a significant number of cases in other countries. There is a lack of published research on the causes and incidence of sudden unexpected deaths in children in SA, and further research in this area is needed

Modification of polyethylene terephthalate track etched membranes by planar magnetron sputtered Ti/TiO2 thin films

This study investigates the surface modification of polyethylene terephthalate track-etched membranes by planar magnetron sputtering of titanium and titanium dioxide thin films to improve its hydrophilicity and photocatalytic activity. After cold plasma treatment to enhanced adhesion, Ti thin films were deposited by planar magnetron sputtering and TiO2 thin films by reactive magnetron sputtering in an Ar-O2 gas atmosphere. The morphology of the deposited thin films was characterised using atomic force microscopy and scanning electron microscopy. The pores retained a mostly circular shape. However, the modified track membrane's surface pore diameter reduced from 0.2 µm to 0.15 µm for Ti coated samples and 0.08 µm for Ti-TiO2 coated samples. Structural studies using X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy and Raman spectroscopy of Ti and TiO2 thin films revealed the intricate composition of the sputtered thin films which was a result of the complexity of sputtering on top of the porous polymer support. Additional investigations in surface wettability and bandgap showed a significant change in the track membrane surface's hydrophilicity and photocatalytic properties after depositing TiO2-Ti, adding to the self-cleaning properties of the coated TM

Human brucellosis in South Africa: Public health and diagnostic pitfalls

Human brucellosis in South Africa (SA) is under-diagnosed and under-reported. This is because many clinicians have little or no experience in managing affected patients, and in part because of the nonspecific and insidious nature of the disease. A case of human brucellosis caused by Brucella melitensis in a patient from the Western Cape Province of SA is described, and the resulting exposure of staff members at two medical microbiology laboratories, as well as the public health investigation that was conducted, are discussed. The objective of this article is to highlight the need for strengthening integration between public health, medical and veterinary services and exposing deficiencies in public health, veterinary and laboratory practices

Proteomic risk markers for coronary heart disease and stroke: validation and mediation of randomized trial hormone therapy effects on these diseases

Background: We previously reported mass spectrometry-based proteomic discovery research to identify novel plasma proteins related to the risk of coronary heart disease (CHD) and stroke, and to identify proteins with concentrations affected by the use of postmenopausal hormone therapy. Here we report CHD and stroke risk validation studies for highly ranked proteins, and consider the extent to which protein concentration changes relate to disease risk or provide an explanation for hormone therapy effects on these outcomes. Methods: Five proteins potentially associated with CHD (beta-2 microglobulin (B2M), alpha-1-acid glycoprotein 1 (ORM1), thrombospondin-1(THBS1), complement factor D pre-protein (CFD), and insulin-like growth factor binding protein 1 (IGFBP1)) and five potentially associated with stroke (B2M, IGFBP2, IGFBP4, IGFBP6, and hemopexin (HPX)) had high discovery phase significance level ranking and an available ELISA assay, and were included in case-control validation studies within the Women’s Health Initiative (WHI) hormone therapy trials. Protein concentrations, at baseline and 1 year following randomization, were assessed for 358 CHD cases and 362 stroke cases, along with corresponding disease-free controls. Disease association, and mediation of estrogen-alone and estrogen plus progestin effects on CHD and stroke risk, were assessed using logistic regression. Results: B2M, THBS1, and CFD were confirmed (P <0.05) as novel CHD risk markers, and B2M, IGFBP2, and IGFBP4 were confirmed as novel stroke disease risk markers, while the assay for HPX proved to be unreliable. The change from baseline to 1 year in B2M was associated (P <0.05) with subsequent stroke risk, and trended similarly with subsequent CHD risk. Change from baseline to 1 year in IGFBP1 was also associated with CHD risk, and this change provided evidence of hormone therapy effect mediation. Conclusions: Plasma B2M is confirmed to be an informative risk marker for both CHD and stroke. The B2M increase experienced by women during the first year of hormone therapy trial participation conveys cardiovascular disease risk. The increase in IGFBP1 similarly conveys CHD risk, and the magnitude of the IGFBP1 increase following hormone therapy may be a mediator of hormone therapy effects. Plasma THBS1 and CFD are confirmed as CHD risk markers, and plasma IGFBP4 and IGFBP2 are confirmed as stroke risk markers. Clinical trials registration ClinicalTrials.gov identifier: NCT0000061

Sudden and unexpected childhood deaths investigated at the Pretoria Medico-Legal Laboratory, South Africa, 2007 - 2011

Background. Sudden and unexpected death is well known to occur in infants, and although sudden deaths are less frequent after the first birthday, they still account for a significant proportion of childhood deaths. In 2009, 1.9% of the total deaths in the USA were childhood deaths. In South Africa (SA) this proportion was much higher at 11.85%. According to the law, sudden and unexpected deaths are generally investigated as unnatural deaths. Establishing an exact underlying anatomical cause of death will depend on available resources and can be difficult in a substantial proportion of cases.Methods. A retrospective descriptive case audit was conducted at the Pretoria Medico-Legal Laboratory (PMLL), SA, from 1 January 2007 through to 31 December 2011. All children aged 1 - 18 years who died suddenly and unexpectedly were included.Results. Ninety-eight cases were identified, which constituted nearly 1% of total admissions to the PMLL. The majority of the deaths were of children aged 1 - 5 years, and the male/female ratio was 1.04:1. In the largest proportion of cases (n=28, 28.6%), the medicolegal investigation, including autopsy and ancillary investigations, did not establish an underlying anatomical cause of death. In the cases where a cause of death was established, pneumonia was the most common diagnosis (n=22, 22.4%).Conclusion. The fact that the cause of the largest proportion of deaths could not be ascertained emphasises the need for consideration of additional investigative techniques, such as molecular/genetic screening, which have provided an underlying cause of death in a significant number of cases in other countries. There is a lack of published research on the causes and incidence of sudden unexpected deaths in children in SA, and further research in this area is needed

Variable contribution identification and visualization in multivariate statistical process monitoring

CITATION: Rossouw, R. F.; Coetzer, R. L. J. & Le Roux, N. J. 2020. Variable contribution identification and visualization in multivariate statistical process monitoring. Chemometrics and Intelligent Laboratory Systems, 198. doi:10.1016/j.chemolab.2019.103894The original publication is available at https://www.sciencedirect.com/journal/chemometrics-and-intelligent-laboratory-systemsMultivariate statistical process monitoring (MSPM) has received book-length treatments and wide spread application in industry. In MSPM, multivariate data analysis techniques such as principal component analysis (PCA) are commonly employed to project the (possibly many) process variables onto a lower dimensional space where they are jointly monitored given a historical or specified reference set that is within statistical control. In this paper, PCA and biplots are employed together in an innovative way to develop an efficient multivariate process monitoring methodology for variable contribution identification and visualization. The methodology is applied to a commercial coal gasification production facility with multiple parallel production processes. More specifically, it is shown how the methodology is used to specify the optimal principal component combinations and biplot axes for visualization and interpretation of process performance, and for the identification of the critical variables responsible for performance deviations, which yielded direct benefits for the commercial production facility.https://www.sciencedirect.com/science/article/pii/S0169743919305088?via%3DihubPublishers versio