32 research outputs found
The South African SHARE-TAVI registry: incidence and risk factors leading to conduction disturbances requiring permanent pacemaker implantation
Background: One of the most common complications post transcatheter aortic valve implantation (TAVI) is the development of heart block requiring permanent pacemaker implantation (PPM). The incidence of PPM in international registries ranges from 13% - 17.5%.
Methods: The aim of this observational study was to report the PPM rate in the SHARE-TAVI registry and determine the clinical, electrocardiographic and procedural predictors of PPM as well as the effect of PPM on clinical outcomes. Results: Three hundred and fi ve subjects were analysed. The PPM rate was 9%. Third degree atrioventricular block at the time of implant was the most common indication for PPM. Self-expanding valves (PPM rate 14% vs. 6% for balloon-expandable valves, p=0.02) were correlated with the need for PPM. Baseline ECG predictors of PPM were axis deviation, QRS duration and conduction delay, most notably a pre-existing right bundle branch block (OR 15.88, p<0.01). PPM infl uenced functional class at 30 days, but not the need for repeat hospitalisation or mortality at 30-day and 1-year follow-up.
Conclusions: A PPM rate lower than that reported in large international registries was found. Predictors of PPM and the infl uence of PPM on outcomes were similar to those reported in the international data
Cardiovascular health risk among university students in South Africa
Tradisioneel is individue se vermoëns, belangstellings en persoonlikhede tydens beroepsvoorligting
en werwings- en keuringsprosesse geassesseer, terwyl slegs enkele studies op die liggaamlike
gesondheid van tweedejaarstudente, as intreevlakwerknemers vir sakeondernemings
in Suid-
Afrika, gefokus het. Die hoofdoel van hierdie navorsing was om die stand van die kardiovaskulêre
gesondheid van universiteitstudente in hul tweede jaar (as intreevlakwerknemers) te bepaal. Die
motivering vir die studie was tweeledig: eerstens om die huidige kardiovaskulêre gesondheidsrisiko
van studente te bepaal, en tweedens om hulle in te lig oor die mate van risiko waaraan hulle
blootgestel is. Die studie was ’n kwantitatiewe deursneestudie wat onderneem is om inligting in te
win oor die kardiovaskulêre gesondheid van universiteitstudente. Die steekproef wat vir hierdie
navorsingstudie gebruik is, het bestaan uit 162 universiteitstudente in Suid-Afrika wat almal tussen
18 en 25 jaar oud was. Die resultate het aangedui dat 55.6% van die betrokke studente aan hoë
bloeddruk gely het. Uit laasgenoemde groep studente is 81.1% as prehipertensief gediagnoseer,
terwyl stadium 1-hipertensie by 18.9% gediagnoseer is. Altesaam 64.8% van al die deelnemende
studente se tellings is in die hoër meetgebied van die Kardiale Stresindeks (KSI). Ongelukkig het
61% van dié studente met verhoogde KSI-tellings ook hoë bloeddruk getoon. Benewens verhoogde
harttempo en bloeddruk het 15.2% van die deelnemers ook swak harttempoveranderlikheid
getoon. Dus het byna 10% van die totale steekproef verhoogde kardiale stresvlakke, verhoogde
harttempo en hoë bloeddrukvlakke vertoon. Die resultate dui daarop dat universiteitstudente
heeltemal onbewus is van hul kardiovaskulêre gesondheid en van die moontlikheid dat dit ’n
invloed op hul loopbane kan hê. Beroepsvoorligters, industriële sielkundiges, opvoedkundige
sielkundiges en praktisyns op die gebied van menslikehulpbronbestuur kan hierdie inligting
voordelig binne die bestek van hul praktyk gebruik om beroepsvoorligting aan fisiologiestudente
te verskaf. Dié praktiese benadering sal fisiologiestudente ook in staat stel om vas te stel wat hul eie
kardiovaskulêregesondheidsrisiko’s is.Traditionally, individuals’
abilities, interests and personality were assessed during career guidance and recruitment and
selection processes; however, only a few studies focused on the actual health of second-year
students, as entry-level employees for business in South Africa. The main research purpose was
to determine the cardiovascular health of second-year university students’ (as young entry-level
employees). The motivations for the study are two-fold: to determine the current cardiovascular
health risk of students, and to educate the students about such risk. The study was a quantitative
cross-sectional study to determine university students’ cardiovascular health. The sample used in
this research study consisted of 162 university students in South Africa, between the ages of 18
and 25 years. The results indicated that 55.6% students had high blood pressure. Then 81.1% of the
latter group of students were identified as prehypertensive, while 18.9% were considered as having
stage-1 hypertension. Students exhibited elevated cardiac stress as well. Altogether 64.8% of all the
participating students scored in the elevated range of the Cardiac Stress Index (CSI). Unfortunately,
61% of the students with elevated CSI readings also exhibited high blood pressure. Furthermore, of
the latter group, 15.2% exhibited poor heart rate variability, as well as elevated heart rate and blood
pressure. Therefore, nearly 10% of the total sample exhibited elevated cardiac stress, an elevated
heart rate and high blood pressure levels. The implications of the results are that university students
are unaware of their cardiovascular health and that it may have an effect on their careers. Career
counsellors, industrial psychologists, educational psychologists, and human resource management
practitioners may benefit from this information in their scope of practice to guide physiology
students in their career. This practical approach also allows physiology students to determine their
own cardiovascular health risks.http://www.satnt.ac.zaam201
Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
Risk and safety requirements for diagnostic and therapeutic procedures in allergology : World Allergy Organization Statement
Peer reviewe
Normal- and reverse-phase paper chromatography of leaf extracts of dandelions
This demonstration describes how normal and reverse phase chromatography can be illustrated using only chromatography paper for the separation of extracts of dandelions.http://dx.doi.org/10.1021/ed200851whttp://pubs.acs.org/doi/pdf/10.1021/ed200851
Integrated positron emission tomography/computed tomography for evaluation of mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosis-endemic area : a 5-year prospective observational study
CITATION: Shaw, J. A., et al. 2015. Integrated positron emission tomography/computed tomography for evaluation of mediastinal lymph node staging of non-small-cell lung cancer in a tuberculosis-endemic area : a 5-year prospective observational study. South African Medical Journal, 105(2):145-150, doi:10.7196/SAMJ.8357.The original publication is available at http://www.samj.org.zaBackground. Integrated positron emission tomography/computed tomography (PET-CT) is a well-validated modality for assessing mediastinal lymph node metastasis in non-small-cell lung cancer (NSCLC), which determines management and predicts survival. Tuberculosis (TB) is known to lead to false-positive PET-CT findings.
Objectives. To assess the diagnostic accuracy of PET-CT in identifying mediastinal lymph node involvement of NSCLC in a high TB-endemic area.
Methods. Patients who underwent both PET-CT and lymph node tissue sampling for the investigation of suspected NSCLC were prospectively included in this observational study. Results were analysed per patient and per lymph node stage. A post-hoc analysis was performed to test the validity of a maximum standardised uptake value (SUVmax) cut-off for lymph node positivity.
Results. PET-CT had a sensitivity of 92.6%, specificity of 48.6%, positive predictive value of 56.8% and negative predictive value (NPV) of 90.0% in the per-patient analysis. Diagnostic accuracy was 67.2%. Similar values were obtained in the per-lymph node stage analysis. TB was responsible for 21.1% of false-positive results. A SUVmax cut-off of 4.5 yielded an improvement in diagnostic accuracy from 64.0% to 84.7% compared with a cut-off of 2.5, but at the cost of decreasing the NPV from 90.6% to 83.5%.
Conclusion. In a high TB-endemic area, PET-CT remains a valuable method for excluding mediastinal lymph node involvement in NSCLC. Patients with a negative PET-CT may proceed to definitive management without further invasive procedures. However, PET-CT-positive lymph nodes require pathological confirmation, and the possibility of TB must be considered.AFRIKAANSE OPSOMMING: Geen opsomming beskikbaarhttp://www.samj.org.za/index.php/samj/article/view/8357Publisher's versio