Individual patient radiation dose tracking: Perceptions of radiographers in South Africa.

INTRODUCTION: Medical imaging examinations that make use of ionising radiation provide valuable information towards patient management. Literature suggests that there is a significant rise in the number of patient referrals for such examinations. The concept "individual patient radiation dose tracking" (IPRDT) is introduced to optimise radiation monitoring. Many countries across the globe explored and implemented methods to enhance and promote the justification and optimisation principles essential for patient radiation safety. In South Africa (SA), however, attention to IPRDT is limited. METHODS: A qualitative research design was employed. Radiographers in the Western Cape Province of SA were purposefully sampled for participation in one-on-one, semi-structured interviews. Thematic analysis was applied to the transcribed interview data. RESULTS: This paper presents a theme developed from the radiographer cohort of ten (10) participants. The theme: the need for creating awareness and implementing legislative support structures, was developed from the data, with the following supporting subthemes: 1) stakeholder awareness and 'buy-in' 2) continuous professional development and 3) mandated practice. CONCLUSION: This study provides findings that are of value for patient radiation safety in SA by giving a voice to local stakeholders. Other countries that are conducting similar research investigations toward the integration of an IPRDT model, method, or framework, may also benefit from these findings. IMPLICATIONS FOR PRACTICE: The effective integration of IPRDT into the clinical environment requires unison amongst the relevant stakeholders and clarity on the various professionals' roles and responsibilities. The findings of this study furthermore suggest the involvement of regulatory organisations for the provision of a mandated form of practice at national and international levels.

Simulation based learning to facilitate clinical readiness in diagnostic radiography. A meta-synthesis.

INTRODUCTION: Simulation based learning (SBL) has been used in diagnostic radiography for teaching and learning purposes. However, the method of offering the SBL opportunities has not been placed in the context of whether the experiences provide the student with a real life simulation. Moreover, in the light of the current staff shortages and healthcare issues in South Africa, placing students into the clinical practice without sound grounding in the application of theory into practice would be unfair to the student and patients. Thus, SBL could provide the opportunity for the student to learn in a safe teaching and learning environment. METHODS: A qualitative, meta- synthesis was undertaken using systematic literature searches. The existing literature in English was retrieved from databases (Medline, CINAHL and ScienceDirect). The keywords used were simulation based learning, simulation, radiography and diagnostic radiography. RESULTS: Themes and categories were developed from the literature. Theme 1: An authentic and realistic situation, which is relevant to the development of a professional in the context of the profession. Theme 2: Building confidence in a safe, reliable and nurturing environment. Theme 3: Active participation in a collaborative process. CONCLUSION: The meta synthesis revealed three major themes that can be used as a framework to motivate for the use of SBL in a diagnostic radiography programme. IMPLICATIONS FOR PRACTICE: The implementation of SBL that could prepare students for the workplace. SBL focused on specific competencies for clinical readiness.

A multi institutional comparison of imaging dose and technique protocols for neonatal chest radiography.

INTRODUCTION: The focus on paediatric radiation dose reduction supports reevaluation of paediatric imaging protocols. This is particularly important in the neonates where chest radiographs are frequently requested to assess respiratory illness and line placement. This study aims to assess the impact of neonatal chest radiographic protocols on patient dose in four hospitals in different countries. METHODS: Exposure parameters, collimation, focus to skin distance (FSD) and radiation dose from 200 neonatal chest radiographs were registered prospectively. Inclusion criteria consisted of both premature and full-term neonates weighing between 1000 and 5000 g. Only data from the examinations meeting diagnostic criteria and approved for the clinical use were included. Radiation dose was assessed using dose area product (DAP). RESULTS: The lowest DAP value (4.58 mGy cm2) was recorded in the Norwegian hospital, employing a high kVp, low mAs protocol using a DR system. The Canadian hospital recorded the highest DAP (9.48), using lower kVp and higher mAs with a CR system, including the addition of a lateral projection. The difference in the mean DAP, weight, field of view (FOV) and kVp between the hospitals is statistically significant (p < 0.001). CONCLUSION: Use of non-standardised imaging protocols in neonatal chest radiography results in differences in patient dose across hospitals included in the study. Using higher kVp, lower mAs and reducing the number of lateral projections to clinically relevant indications result in a lower DAP measured in the infant sample studied. Further studies to examine image quality based on exposure factors and added filtration are recommended. IMPLICATIONS FOR PRACTICE: Reevaluation of paediatric imaging protocols presents an opportunity to reduce patient dose in a population with increased sensitivity to ionising radiation.

A quantitative analysis of microplastic pollution along the south-eastern coastline of South Africa.

The extent of microplastic pollution (<5mm) in the southern hemisphere, particularly southern Africa, is largely unknown. This study aimed to evaluate microplastic pollution along the south-eastern coastline of South Africa, looking at whether bays are characterised by higher microplastic densities than open stretches of coastline in both beach sediment and surf-zone water. Microplastic (mean ± standard error) densities in the beach sediment ranged between 688.9 ± 348.2 and 3308 ± 1449 particles · m(-2), while those in the water column varied between 257.9 ± 53.36 and 1215 ± 276.7 particles · m(-3). With few exceptions there were no significant spatial patterns in either the sediment or water column microplastic densities; with little differences in density between bays and the open coast (P>0.05). These data indicate that the presence of microplastics were not associated with proximity to land-based sources or population density, but rather is governed by water circulation.

[Metformin, renal function and lactate: the MetClear Study]. / Metformine, nierfunctie en lactaat: het MetClear-onderzoek.

OBJECTIVE: To map the relation between metformin prescription and renal function in an outpatient setting. To investigate whether there is an association between renal function, metformin concentration and lactate concentration. DESIGN: Pilot for a prospective observational cohort study. METHOD: We included outpatients with diabetes mellitus type 2 who were treated with metformin. At inclusion, we determined the HbA1c, lactate, metformin and creatinine concentrations and the estimated glomerular filtration rate (eGFR). Information on the prescribed dosage of metformin was acquired from patient files. Our primary outcome measure was the number of patients in whom the dose was not adjusted to the renal function. Our secondary outcome measure was the difference in median lactate concentration between patients with a normal (≤ 2.5 mg/l) and an increased (> 2.5 mg/l) metformin concentration. RESULTS: Eighty-eight patients were included, 12 (14%) of whom had an eGFR ≤ 30, 31 (36%) an eGFR of 30-50 and 44 (50%) an eGFR > 51 ml/min/1.73 m2. In 27 (31%) of all patients, the daily dose of metformin exceeded the dose recommended in the practice guidelines. The 28 patients with an increased metformin concentration had a significantly higher median lactate concentration: 2.3 mmol/l compared to 1.5 mmol/l for the 60 patients with a normal metformin concentration (p < 0.0001). CONCLUSION: Our study shows that in outpatient practice, the metformin dose is not sufficiently adjusted to a reduced renal function in 31% of the patients. The accumulation of metformin appears to be associated with an increased lactate concentration and a reduced renal function. Extra attention to the dose of metformin in reduced renal clearance is therefore recommended.

Blood-brain barrier integrity in a zolpidem-responder patient.

A 27-year-old neurologically disabled but fully conscious male zolpidem-responder patient was investigated for blood brain barrier (BBB) dysfunction 5 years after a traumatic brain injury. A baseline single-photon emission computed tomography (SPECT) technetium-99m-labelled hexamethylpropylene amine oxime (99mTcHMPAO) brain scan was performed and the patient was administered 10 mg zolpidem daily. The patient was rescanned 2 weeks later when 99mTcHMPAO was injected 1 hour after zolpidem application. SPECT technetium-99m-labelled diethylene-triamine-pentacetic acid (99mTcDTPA) BBB scans were also performed before and after zolpidem treatment. There was decreased uptake of 99mTcHMPAO in the left frontoparietal brain region, left temporal region and left thalamus on baseline scanning; this improved within 1 hour after zolpidem treatment at the follow-up scan. The 99mTcDTPA scan remained within normal limits before and after zolpidem treatment. The patient's neurological disabilities, especially coordination, speech and gait, improved markedly. The Barthel Index remained normal, but the Tinetti falls efficacy scale improved from 21/100 to 15/100. The results implied that the underlying cause for the patient's long-term neurological disability and brain suppression was not due to a long-term dysfunctional BBB.

Effect of desloratadine on patients with allergic rhinitis and exercise-induced bronchoconstriction: a placebo controlled study.

BACKGROUND: Exercise induced broncho-constriction (EIB) is a significant problem in asthmatic patients. The link between allergic rhinitis and asthma is now well established. Patients with allergic rhinitis may have EIB. OBJECTIVE: This study compared the effects of desloratadine and placebo on EIB in a group of patients with allergic rhinitis and EIB. METHODS: This was a double blind placebo controlled, randomized, crossover study. Exercise challenge tests were performed before and after 7 days of treatment with either 5 mg desloratadine or placebo. Patients then underwent a washout period for 7 days and were crossed over to receive either 5mg desloratadine or placebo. The exercise challenge tests were repeated. RESULTS: Desloratadine had no effect on the reduction in percentage fall in FEV(1), the AUC (0-60 min) and the time to recovery. CONCLUSIONS: Desloratadine has no effect in attenuating the broncho-constriction caused by exercise in patients with allergic rhinitis and exercise induced broncho-constriction. CLINICAL IMPLICATIONS: Patients with allergic rhinitis and exercise induced broncho-constriction must be treated with either a beta(2)-agonist or LRTA for relief or prophylaxis of their EIB. CAPSULE SUMMARY: Desloratadine does not have an effect on exercise induced bronchoconstriction. Patients with allergic rhinitis with exercise induced bronchoconstriction who are on desloratadine will still require treatment with beta(2) agonist or leukotriene receptor antagonist for their symptoms.

Towards the establishment and standardization of a veterinary antimicrobial resistance surveillance and monitoring programme in South Africa.

The objective of this study was to establish a repeatable, standardized laboratory procedure for monitoring the development of antimicrobial resistance in bacteria isolated from animals and food of animal origin in South Africa, with reagents prepared in-house. The emergence of resistance and the spread of resistant bacteria can be limited by implementing a veterinary antimicrobial drug policy, in which inter alia systematic monitoring and prudent use play essential roles. The bacteria included in this study represented three different categories, namely zoonotic bacteria (Salmonella), indicator bacteria (Escherichia coli, Enterococcus faecalis and Enterococcus faecium) and veterinary pathogens (Mannheimia haemolytica). Thirty isolates of each species were collected with the aim of standardizing the laboratory methodology for a future national veterinary surveillance and monitoring programme. Susceptibility to ten selected antimicrobial drugs was determined by means of minimum inhibitory concentrations (MICs) using the microdilution method. The method according to the National Committee for Clinical Laboratory Standards was used as the standard. Multi-well plates containing varying dilutions of antimicrobial drugs and prepared in-house for MIC determinations, yielded repeatable results. Storage of plates for 2 months at -70 degrees C did not influence results meaningfully. Within this limited sample of bacteria, MIC results did not indicate meaningful resistance against any of the ten selected antimicrobial drugs. The findings of the study will be used to establish a national veterinary antimicrobial resistance surveillance and monitoring programme in South Africa. To allow for international comparison of data, harmonisation of the surveillance and monitoring programme in accordance with global trends is encouraged. Ideally it should be combined with a programme monitoring the quantities of antimicrobial drugs used. The aim is to contribute to slowing down the emergence of resistance and the problems associated with this phenomenon by means of the rational use of antimicrobial drugs.

PAH biotransformation in terrestrial invertebrates--a new phase II metabolite in isopods and springtails.

Soil-living invertebrates are exposed to high concentrations of contaminants accumulating in dead organic matter, such as polycyclic aromatic hydrocarbons (PAHs). The capacity for PAH biotransformation is not equally developed in all invertebrates. In this paper, we compare three species of invertebrates, Porcellio scaber (Isopoda), Eisenia andrei (Lumbricidae) and Folsomia candida (Collembola), for the metabolites formed upon exposure to pyrene. Metabolic products of pyrene biotransformation in extracts from whole animals or isopod hepatopancreas were compared to those found in fish bile (flounder and plaice). An optimized HPLC method was used with fluorescence detection; excitation/emission spectra were compared to reference samples of 1-hydroxypyrene and enzymatically synthesized conjugates. Enzymatic hydrolysis after fractionation was used to demonstrate that the conjugates originated from 1-hydroxypyrene. All three invertebrates were able to oxidize pyrene to 1-hydroxypyrene, however, isopods and collembolans stood out as more efficient metabolizers compared to earthworms. In contrast to fish, none of the invertebrates produced pyrene-1-glucuronide as a phase II conjugate. Both Collembola and Isopoda produced significant amounts of pyrene-1-glucoside, whereas isopods also produced pyrene-1-sulfate. A third, previously unknown, conjugate was found in both isopods and springtails, and was analysed further using electrospray and atmospheric pressure chemical ionisation mass spectrometry. Based on the obtained mass spectra, a new conjugate is proposed: pyrene-1-O-(6"-O-malonyl)glucoside. The use of glucose-malonate as a conjugant in animal phase II biotransformation has not been described before, but is understandable in the microenvironment of soil-living invertebrates. In the earthworm, three other pyrene metabolites were observed, none of which was shared with the arthropods, although two were conjugates of 1-hydroxypyrene. Our study illustrates the great variety of the still unexplored metabolic diversity of invertebrate xenobiotic metabolism.

Pyrene biotransformation products as biomarkers of polycyclic aromatic hydrocarbon exposure in terrestrial Isopoda: concentration-response relationship, and field study in a contaminated forest.

In this study, biotransformation products of pyrene were measured in the hepatopancreas of terrestrial isopods as biomarkers of polycyclic aromatic hydrocarbon (PAH) exposure. These products--pyrene-1-glucoside, pyrene-1-sulfate, an unknown pyrene conjugate, and 1-hydroxypyrene--were quantitated using high-performance liquid chromatography (HPLC) with fluorescence detection. In a controlled exposure experiment, a linear relationship was established between pyrene exposure and pyrene metabolite concentrations in the hepatopancreas of Porcellio scaber Latr. To this end, isopods of the species P. scaber were exposed to a range of pyrene concentrations spiked to their food. A linear response was found for all pyrene conjugates in the range 0.67 to 67 microg/g of pyrene (dry wt). Hepatopancreatic pyrene metabolite concentrations were also measured in isopods (P. scaber and Oniscus asellus L.) from PAH-contaminated field sites. The sites and the inhabiting isopods were located in a gradient of atmospheric PAH deposition caused by a nearby blast furnace plant. The highest levels of conjugated 1-hydroxypyrene in the hepatopancreas were 3.8 pmol/g fresh weight (pyrene-1-glucoside) and 2.8 pmol/g fresh weight (pyrene-1-sulfate) (expressed on whole-body basis). The levels of the pyrene metabolites correlate with reported pyrene concentrations in spite of these sites. As pyrene is one of the most predominant PAHs, analysis of its metabolites provides a good tool for environmental risk assessment of ecosystems with regard to PAH exposure, bioavailability, and biotransformation.

Growth optimization of Pediococcus damnosus NCFB 1832 and the influence of pH and nutrients on the production of pediocin PD-1.

AIMS: Optimization of the growth of Pediococcus damnosus NCFB 1832 and the production of pediocin PD-1 by traditional fermentation methods. METHODS AND RESULTS: Fermentation studies were conducted in De Man Rogosa and Sharpe (MRS) broth (Oxoid), preadjusted to specific pH values, and in MRS broth supplemented with various nitrogen sources, MnSO4, MgSO4 and Tween 80. The production of pediocin PD-1 closely followed the growth curve of Ped. damnosus NCFB 1832. Maximum levels of bacteriocin activity (3249 AU ml(-1)/O.D.max) were recorded in MRS broth with an initial pH of 6.7. In media with an initial pH of 4.5 bacteriocin activity as low as 222 AU ml(-1)/O.D.max was recorded. The highest bacteriocin activity was recorded in growth conditions allowing the greatest pH variation (highest DeltapH). The addition of bacteriological peptone (1.7%, w/v), MnSO4 (0.014%, w/v) and Tween 80 (3%, v/v) to MRS and adjustment of the medium pH to 6.7 resulted in a further increase in activity (from 3249 to 5078 AU ml(-1)/O.D.max). The same medium, but with an initial pH of 6.2, resulted in an 82.5% decrease in bacteriocin activity. CONCLUSIONS: Pediocin PD-1 production is not only stimulated by the presence of specific growth factors (e.g., bacteriological peptone, MnSO4 or Tween 80), but may also be stimulated by the lowering in pH during growth (highest DeltapH), and thus also the amount of organic acids produced. SIGNIFICANCE AND IMPACT OF THE STUDY: The production of pediocin PD-1 by the wild-type producer strain was significantly improved by using a defined medium and traditional fermentation methods.

Extraordinary arousal from semi-comatose state on zolpidem. A case report.

A young semi-comatose male patient was investigated using 99mTc hexamethyl-propylene amine oxime (99mTc HMPAO) brain single photon emission computed tomography (SPECT) before and after administration of the gamma-aminobutyric acid (GABA) agonist zolpidem. It was observed that 15 minutes after application of the drug the patient awoke from his semi-comatose condition and remained awake for the next 3-4 hours. When drug action subsided he returned to his semi-comatose state. Brain SPECT before drug application showed large hypo-active areas in certain parts of the brain. Brain SPECT after drug application showed a generalised cortical activation relative to the cerebellum and a marked and amplified activation of the areas that were hypo-active before drug application.

Pyrene metabolites in the hepatopancreas and gut of the isopod porcellio scaber, a new biomarker for polycyclic aromatic hydrocarbon exposure in terrestrial ecosystems.

The object of this study was to investigate the formation of pyrene metabolites by the isopod Porcellio scaber as a possible tool in the environmental risk assessment of polycyclic aromatic hydrocarbon (PAH) exposure in terrestrial ecosystems. The formation of pyrene metabolites was studied after either pulse exposure to a single high dose, or prolonged exposure (14 d) to a lower dosage. Exposure studies were carried out with unlabeled or radiolabeled pyrene, ion pair chromatography was used for analysis, and reference conjugates were synthesized. We also measured pyrene metabolites in field-exposed animals, to explore their use as biomarkers of PAH exposure. Analysis of the hepatopancreas and gut of single isopods revealed the formation of five products, one of which was 1-hydroxypyrene. Four of the remaining products were identified as phase II metabolites of 1- hydroxypyrene, with UV absorption and fluorescence characteristics similar to that of pyrene. One metabolite was identified as pyrene-1-glucoside, which is in accordance with high rates of glucosidation, reported for these isopods. Another conjugate was identified as pyrene-1-sulfate. None of the metabolites coeluted with a pyrene-1-glucuronide reference obtained from fish bile. A fifth metabolite detected by on-line scintillation detection did not exhibit any absorption at 340 nm, possibly because one of the aromatic rings of pyrene had lost its aromatic character. Although pyrene is not known for its toxicity, it usually co-occurs with other PAHs that are transformed into toxic products. Investigating the metabolism of pyrene can provide information with regard to the biotransformation capacity of invertebrate species and uptake and elimination kinetics. Because pyrene is one of the most predominant PAHs in the environment, analysis of its metabolites provides an extra tool for the environmental risk assessment of ecosystems with regard to PAH exposure, bioavailability, and biotransformation.

Scanning electron microscopy evaluation of the interfacial fit of interchanged components of four dental implant systems.

The introduction of the original Swedish implant system (Brånemark) was followed by several alternative implant systems with implants and components that closely resembled the original design and treatment protocol. Some of these alternative systems may be interchangeable. Manufacturing variations can result in as much as 0.1 mm of space between the component parts. The implant/abutment interface fit was evaluated by scanning electron micrography for each of four implant systems, as well as interchanged components between the various systems. Results showed that certain implant system abutments are interchangeable, and that the accuracy of fit meets with or exceeds the criteria set by the original Swedish system.

The prevalence of the larval stage of Taenia ovis at the Port Elizabeth Abattoir.

The prevalence of the larval stage of Taenia ovis and the origin of the animals were recorded for a period of 39 days at the Port Elizabeth abattoir. Cysticercosis was more frequently found in the M. triceps brachii of sheep, but the actual cysticerci were fewer than those found in the semimembranosus, semitendinosus, adductor, biceps femoris, vastus, rectus femoris and gracilis group of muscles of the hind limb (leg muscles). Most animals originated from farms in the Oudtshoorn district.

[Antibiotic peritoneal lavage in acute peritonitis resulting from septic abortion or a ruptured pyosalpinx]. / Antibiotiese peritoneale lavage in akute peritonitis as gevolg van septiese abortus of 'n geruptuurde piosalpinks.

An analysis is given of 16 patients who presented with acute peritonitis during the years 1976-1978 and who were treated by means of antibiotic peritoneal lavage. The history and technique of peritoneal laage are discussed.

Myofascial pain-dysfunction syndrome.

Of the 127 patients treated for MPDS over a 30 month period, only six patients did not make at least a 90% recovery within 3 to 4 months. In most instances a spectacular degree of success was achieved within 2 to 3 weeks. Ten percent of the patients who were treated had had symptoms of the MPDS for a period longer than 5 years. These patients are usually more difficult to treat, and should receive extra attention. In patients with a long-standing history of MPDS it is advisable to apply all seven phases of treatment.