57 research outputs found
The knowledge, awareness and practices of radiation safety amongst orthopaedic surgeons
BACKGROUND : Fluoroscopic imaging in orthopaedic theatres is increasing, with added risk to the
orthopaedic surgeon who is increasingly being exposed to ionising radiation. It is thus crucial for
orthopaedic surgeons to have a working knowledge of radiation safety. In spite of these concerns,
however, many orthopaedic surgeons do not receive standard training in radiation safety.
OBJECTIVES : The evaluation of orthopaedic surgeons’ knowledge, awareness and everyday
practices regarding radiation safety in an academic hospital.
METHODS : A questionnaire with multiple-choice-type questions was developed by a panel of
experts and used to conduct a descriptive study. The questionnaire had multiple dimensions,
each evaluating orthopaedic knowledge, awareness and practices, respectively. The study
population included orthopaedic surgeons rotating within the orthopaedic circuit of the
University of Pretoria.
RESULTS : Orthopaedic surgeons regularly make use of fluoroscopic imaging in theatre, with 34
(77%) participants indicating that they use fluoroscopy in more than half of all their procedures
performed. Most participants have insufficient knowledge of radiation safety, with the majority
failing to correctly answer basic questions on radiation safety. Forty (91%) participants do not
wear personal dosimeters, in spite of 39 participants (89%) believing that they are vulnerable
to adverse effects. Basic radiation protection devices are underutilised, with 32 (73%)
participants indicating that they have not received adequate training in radiation safety.
CONCLUSION : The majority of orthopaedic surgeons regularly use fluoroscopic imaging in
theatre yet lack in-depth knowledge and awareness regarding radiation safety associated with
this imaging modality. Implementation of a radiation safety training programme is thus
recommended.Dissertation was completed at the University of Pretoria:http://www.sajr.org.zaam2021Radiolog
Migraine-associated vertigo and dizziness as presenting complaint in a private general medical practice
Migraine-associated vertigo (MV) remains a developing entity because accepted diagnostic criteria are
unavailable. Patients present with debilitating dizziness without experiencing headache, and are often misdiagnosed as
anxious. The condition is manageable in primary care without the need for neurological referral. The aim of this study was
to investigate the prevalence of MV and migraine-associated dizziness (MD) as presenting complaints.
Methods: Patients presented with dizziness probably or definitely associated with migraine history based on the criteria of
the International Headache Society. Patients with other vestibulopathies and medical conditions were excluded. Patients
were evaluated over a period of nine months. Seven hundred and seventeen patients were examined. The numbers of
patients were recorded as a percentage of the population visiting a general practitioner. Response to migraine prophylactic
medications was regarded as supporting evidence of the diagnosis. Response was regarded as a complete resolution of
symptoms.
Results: Of the 717 patients seen, 12 were identified as having probable or definite MV. Five patients were treated with
migraine prophylactic medications, namely amitriptyline 25 mg nocte and/or sodium valproate CR 300 mg bd, and all
showed a response to the treatment.
Conclusions: We conclude that the prevalence of MV as presenting complaint may be as high as 1.67%. This figure does
however not reflect the total patient population that suffers from the condition – this figure may be much higher. Of those
patients treated for MV the response was 100%, further supporting the diagnosis. MV is a relevant complaint that is often
misdiagnosed as psychogenic in origin
In vitro osteoclast-like and osteoblast cells' response to electrospun calcium phosphate biphasic candidate scaffolds for bone tissue engineering
Successful long term bone replacement and repair remain a challenge today. Nanotechnology
has makes it possible to alter materials’ characteristics and therefore possibly improve on the
material itself. In this study, biphasic (hydroxyapatite/β-tricalcium phosphate (HA/β-TCP))
nanobioceramic scaffolds were prepared by the electrospinning technique in order to mimic
the extracellular matrix (ECM). Scaffolds were characterised by scanning electron
microscopy (SEM) and Attentuated Total Reflectance Fourier Transform Infrared (ATRFTIR).
Osteoblasts as well as monocytes that were differentiated into osteoclast-like cells,
were cultured separately on the biphasic bioceramic scaffolds for up to 6 days and the
proliferation, adhesion and cellular response were determined using lactate dehydrogenase
(LDH) cytotoxicity assay, nucleus and cytoskeleton dynamics, analysis of the cell cycle
progression, measurement of the mitochondrial membrane potential and the detection of
phosphatidylserine expression. SEM analysis of the biphasic bioceramic scaffolds revealed
nano fibers spun in a mesh-like scaffold. Results indicate that the biphasic bioceramic
electrospun scaffolds are biocompatible and have no significant negative effects on either
osteoblasts or osteoclast-like cells in vitro.Council for Scientific and Industrial Research (CSIR), Pretoria, South Africa.http://www.springer.com/materials/journal/10853hb201
HFOB 1.19 osteoblast cells grown on a biomimetic biphasic nanoscaffold : an in vitro evaluation for possible bone tissue engineering
Much research over the past five decades has focussed on the repair and replacement of bone. Recently,
the research focus has shifted to nanotechnology since it provides a platform from which to alter and
possibly improve materials’ properties. In this study we have made use of previously developed
electrospun biphasic nanoscaffolds to culture osteoblast cells on, and investigate specific responses of the
cells towards the scaffolds. Osteoclast-like cells and osteoblast cells were cultured separately on the
nanoscaffolds and the proliferation, adhesion and cellular response were determined. In this study, the
mineralisation of the osteoblast cells was observed in a time study. The intracellular calcium ion
concentration and nitric oxide concentration were determined in vitro while the cells were proliferating
on the scaffolds. The expression of endothelial and inducible nitric oxide synthase was determined
immunohistochemically. Quantitative data were obtained from fluorometer studies. Qualitative data was
supplied by light- and fluorescent confocal microscopy. During studies with microscopy, a minimum of
five representative images from each sample were captured. The cells showed increased mineralisation
over time. An increase in intracellular Ca2+ was not observed when compared to the controls. However,
an increase in intracellular nitric oxide formation was detected. Expression of endothelial nitric oxide
synthase but not inducible nitric oxide synthase was detected in vitro. From the results we can conclude
that the scaffolds are biocompatible and conducive to healthy cell growth and differentiation and could
possibly be applied in non-load-bearing bone regeneration and repair applications.http://www.biomedres.infoam2019Physiolog
The in vitro effects of a sulphamoylated derivative of 2-methoxyestradiol on cell number, morphology and alpha-tubulin disruption in cervical adenocarcinoma (HeLa) cells
2-Methoxyestradiol (2ME2) is an endogenous metabolite of estrogen that has both antiangiogenic and antitumor effects. However, the shortcoming with 2ME2 is that it is rapidly inactivated by 17β-hydroxysteroid dehydrogenase type 2. Thus a bis-sulphamoylated derivative
of 2ME2, 2-Methoxyestradiol-bis-sulphamate (2MEBM) was synthesized in order to address the shortcoming of 2ME2. The aim of this in vitro study was to investigate the influence of 2MEBM on cell growth, morphology and tubulin structure in a cervical cancer (HeLa) cell line. Dose-dependent studies revealed that 0.55ÎĽM of 2MEBM inhibited cell
growth by 50%. 2MEBM-treated cells showed an increase in the number of metaphase cells, apoptotic cells, and disrupted tubulin structure after 48 hours of exposure to 0.55ÎĽM of 2MEBM. Future studies will be conducted to further investigate the mechanism of action of 2MEBM in cervical carcinoma cells.Grants from the Cancer Association of South Africa (AK246), the Medical Research Council (AG374, AK076), National Research Foundation and Struwig Germishuysen Trust (AJ038).http://www.jstage.jst.go.jp/browse/biomedre
Changes in red blood cell membrane structure in type 2 diabetes : a scanning electron and atomic force microscopy study
Red blood cells (RBCs) are highly deformable and possess a robust membrane that can withstand shear force.
Previous research showed that in diabetic patients, there is a changed RBC ultrastructure, where these cells are
elongated and twist around spontaneously formed fibrin fibers. These changes may impact erythrocyte function.
Ultrastructural analysis of RBCs in inflammatory and degenerative diseases can no longer be ignored and should
form a fundamental research tool in clinical studies. Consequently, we investigated the membrane roughness and
ultrastructural changes in type 2 diabetes. Atomic force microscopy (AFM) was used to study membrane roughness
and we correlate this with scanning electron microscopy (SEM) to compare results of both the techniques with the
RBCs of healthy individuals. We show that the combined AFM and SEM analyses of RBCs give valuable information
about the disease status of patients with diabetes. Effectiveness of treatment regimes on the integrity, cell shape
and roughness of RBCs may be tracked, as this cell’s health status is crucial to the overall wellness of the diabetic
patient.http://cardiab.biomedcentral.comam2016Physiolog
Novel in silico-designed estradiol analogues are cytotoxic to a multidrug-resistant cell line at nanomolar concentrations
PURPOSE : 2-Methoxyestradiol (2ME) is a promising anticancer
agent that disrupts the integrity and dynamics of the
spindle network. In order to overcome the pharmacokinetic
constraints of this compound, a panel of sulphamoylated
estradiol analogues were in silico-designed by our laboratory.
In this study, we analysed the potential of each analogue
to induce cell death on a panel of cancer cell lines.
Moreover, the mechanism of action of the most effective
compounds was determined.
METHODS : Cytotoxicity screening of the compounds and
intermediates was performed on five different cancer cell
lines to determine IG50 values. An in vitro tubulin polymerization
assay was done to determine the effect of the drugs
on tubulin polymerization while their intracellular effects
on the microtubule network were assessed by immunofluorescence
microscopy.
RESULTS : IG50 calculations showed that the sulphamoylated
analogues induce cytotoxicity at nanomolar concentrations
in all cell lines, including the P-glycoprotein pump overexpressing multidrug-resistant uterine sarcoma cell
line. The non-sulphamoylated compounds were only cytotoxic
at micromolar ranges, if at all. The sulphamoylated
compounds inhibited pure tubulin polymerization in a
dose-dependent manner and induced microtubule destruction
in cells after 24-h exposure.
CONCLUSION : Results revealed that the novel sulphamoylated
2ME derivatives have potential as anti-cancer
drugs, possibly even against chemoresistant cancer cells.
These compounds disrupt the intracellular microtubule
integrity which leads to mitotic block of the cells.The Research Development Programme of the University of Pretoria (RDP AOV840), the South African Medical Association (SAMA), the National Research Foundation (NRF Project # 86475, N00465, N00375, N00591), the Research Committee of the Faculty of Health Sciences, University of Pretoria (RESCOM), CANSA (AOV741, AOW228) and the Medical Research Council (MRC AOW110).http://link.springer.com/journal/2802016-02-28hb201
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