Weight gain in patients after therapy for hyperthyroidism

Objective. To determine the prevalence of obesity following therapy for hyperthyroidism and to assess the contributing factors associated with an undesirable weight gain.Design. A retrospective analysis was undertaken of clinical records for 160 hyperthyroid patients attending an endocrine clinic in Bloemfontein (1994 - 2001).Results. Of the 160 patients, 143 had Graves' disease and 17 patients had multinodular goitre. Most of our patients (N = 147) were treated with radioiodine, 10 patients with carbimazole and 3 patients had thyroidectomy. The median weight gain 6 months after therapy was 5.0 kg, after 12 months 9.0 kg, and after 24 months 12 kg, whereafter body mass stabilised. Before therapy 27.5% of patients had a body mass index (BMI) of < 22 kg/m2, 29.4% were overweight (BMI > 25 kg/m2) and 19.3% were obese (BMI > 30 kg/m2). Two years after treatment only 8.7% of patients had a BMI of < 22 kg/m2, 27.5% had a BMI > 25 kg/m2, and 51.3% had become obese. The main factors associated with weight gain 24 months after therapy were poor control of thyroid function on replacement therapy, diagnosis of Graves' disease and need for thyroxine replacement.Conclusion. This study has shown a large increase (32%) in the prevalence of obesity following treatment for hyperthyroidism. The main weight gain was during the first 2 years after therapy. The main factors contributing to excessive weight gain were need for replacement therapy and poor control of thyroid function

Investigating partial least squares discriminant analysis and hierarchical modelling of short wave infrared hyperspectral imaging data to distinguish production area and quality of rooibos (Aspalathus linearis)

Short wave infrared hyperspectral imaging was tested for its ability to distinguish rooibos tea (Aspalathus linearis) based on production area and quality grade, with the aim to replace time-consuming sensory analysis in the industry. The number of latent variables and model parameters of the calibration model were optimised by cross-validation. Classification error rates were used to evaluate the performance of the models in classifying rooibos based on production area and quality grade. The production area of rooibos was distinguished by applying a partial least square-discriminant analysis model with second derivative pre-processing, followed by mean centering and inclusion of nine LVs. The model could successfully distinguish between the two production areas and had a classification accuracy of 100% for the prediction set. To distinguish between different quality grades, a hierarchical model with second derivative pre-processing was developed. Grade A could be distinguished successfully from grades B, C and D (class BCD) with 100% accuracy and grade D could be distinguished from grades B and C (class BC) with 96% accuracy. However, the model was less accurate to distinguish between grade B and C samples, with prediction accuracies of 82 and 66% for B and C, respectively. Application of near infrared hyperspectral imaging therefore offers the potential to replace the use of sensory analysis in the rooibos tea industry to predict production area and quality grade of this herbal tea

Maceration Before and During Fermentation: Effect on Pinotage Wine Phenolic Composition, Total Antioxidant Capacity and Objective Colour Parameters

Low-temperature maceration treatments (1, 2 and 4 days at 10 and 15°C) before fermentation and juice/skin mixing treatments (punching-down, pumping-over and rotor action every hour and every 3 hours) duringfermentation were investigated in terms of their effects on Pinotage wine phenolic composition, total antioxidant capacity (TAC) and colour over three vintages (2000 to 2002). Results for pre-fermentation maceration were notconsistent between vintages. Very few significant differences in the phenolic content, TAC and objective colour parameters were observed between the control wines and wines subjected to different pre-fermentation macerationtreatments. Pre-fermentation maceration, especially at 15°C, resulted in wines with increased vitisin A content.  Improvement of wine quality when using pre-fermentation maceration treatments at 10°C was noted previously, while no detrimental effect on the wine TAC was observed. The pumping-over treatment yielded wines with lower TAC and phenol content, as well as less favourable objective colour values, indicating that the punching-down or rotor treatment would be preferred. Although mixing at hourly intervals yielded a higher content of some phenolic compounds compared to the 3-hour interval mixing, mixing frequency did not affect the TAC of the wine. The objective colour parameters, h* and b*, were slightly lower at the higher mixing frequency in 2002 indicating a shift in the direction of a magenta hue

Global conformations, hydrodynamics, and x-ray scattering properties of Taq and Escherichia coli DNA polymerases in solution

Escherichia coli polymerase 1 (Pol 1) and Thermus aquaticus Taq polymerase are homologous Type I DNA polymerases, each comprised of a polymerase domain, a proofreading domain (inactive in Taq), and a 5′ nuclease domain. Klenow and Klentaq are the large fragments of Pol 1 and Taq and are functional polymerases lacking the 5′ nuclease domain. In the available crystal structures of full-length Taq, the 5′ nuclease domain is positioned in two different orientations: in one structure, it is extended out into solution, whereas in the other, it is folded up against the polymerase domain in a more compact structure. Analytical ultracentrifugation experiments report s20,w values of 5.05 for Taq, 4.1 for Klentaq, 5.3 for E. coli Pol 1, and 4.6 for Klenow. Measured partial specific volumes are all quite similar, indicating no significant differences in packing density between the mesophilic and thermophilic proteins. Small angle x-ray scattering studies report radii of gyration of 38.3 Å for Taq, 30.7 Å for Klentaq, and 30.5 Å for Klenow. The hydrodynamic and x-ray scattering properties of the polymerases were also calculated directly from the different crystal structures using the programs HYDROPRO (Garcia De La Torre, J., Huertas, M. L., and Carrasco, B. (2000) Biophys J. 78, 719-730) and CRYSOL (Svergun, D. I., Barberato, C., and Koch, M. H. J. (1995) J. Appl. Crystalogr. 28, 768-773), respectively. The combined experimental and computational characterizations indicate that the full-length polymerases in solution are in a conformation where the 5′ nuclease domain is extended into solution. Further, the radius of gyration, and hence the global conformation of Taq polymerase, is not altered by the binding of either matched primer template DNA or ddATP

Editorial

South Africa’s vital statistics are currently not suitable for monitoring progress towards injury and violence Sustainable Development Goal

Active drug targeting

Over 100 years ago, Paul Ehrlich first proposed the side-chain theory to explain how living cells mount an immune response in reaction to an infection. His theory stated that upon the encounter of a threat, cells express side-chains to bind dangerous toxins. These side-chains, which he later named receptors, can break off the cell and circulate throughout the body (i.e. antibodies). Specific antibodies link to particular antigens in the same way that Emil Fischer proposed enzymes bind to their receptors, “as lock and key”. Ehrlich described these so-called “keys” or antibodies as “magic bullets”, which target toxins without harming the body. In recent years, research has focused on using antibodies not only for detection of infection, but also as aids for drug targeting. Thereby, antibodies are bound to the surface of carriers (e.g. nanoparticles) and facilitate a directed transport to a specific organ or site in the body. Aptamer- peptide- or folic acid-doped carriers furthermore have been shown to specifically target cancer cells. By using hydrophilic structures as carriers (e.g. polyethylene glycol), negative side effects resulting from the accumulation of innate proteins can be prevented. Currently, there are drug carriers in the pre-clinical development phase for the treatment of bowel cancer. Thereby, nano polymer capsules coated with a specific antibody are used to target a glycoprotein expressed on bowel cancer cells. The polymers have a size of approximately 500 nm and are produced with a so-called “layer-by-layer” procedure. Once the carrier has reached its target site, the drug needs to be released in a controlled manner. This can be facilitated, for example, by applying a magnetic field in the case of iron oxide particles. Once these particles are taken up by the cells, magnetic radiation can be used to excite the particles, resulting in the rupture of the cell and subsequent cell death

Telling stories in science communication: case studies of scholar-practitioner collaboration

Reflecting on the practice of storytelling, this practice insight explores how collaborations between scholars and practitioners can improve storytelling for science communication outcomes with publics. The case studies presented demonstrate the benefits of collaborative storytelling for inspiring publics, promoting understanding of science, and engaging publics more deliberatively in science. The projects show how collaboration between scholars and practitioners [in storytelling] can happen across a continuum of scholarship from evaluation and action research to more critical thinking perspectives. They also show how stories of possible futures and community efficacy can support greater engagement of publics in evidence-informed policymaking. Storytelling in collaborations between scholars and practitioners involves many activities: combining cultural and scientific understandings; making publics central to storytelling; equipping scientists to tell their own stories directly to publics; co-creating stories; and retelling collaborative success stories. Collaborative storytelling, as demonstrated in these case studies, may improve the efficacy of science communication practice as well as its scholarship.info:eu-repo/semantics/publishedVersio

Errors in drug administration by anaesthetists in public hospitals in the Free State

Objective. To investigate errors in administering drugs by anaesthetists working in public hospitals in the Free State province. Methods. Anonymous questionnaires were distributed to doctors performing anaesthesia in public hospitals in the Free State, i.e. 188 doctors at 22 public sector hospitals. Outcomes included demographic information on respondents, information regarding the administration of anaesthetics, reporting of errors, and the occurrence of errors during anaesthesia. Results. The response rate was 46.3%; 48.8% were medical officers, and 39.3% of participants were involved in at least one event of erroneous drug administration. Registrars and specialists reported the most errors. Most events were of no clinical significance, caused no permanent harm to patients, and most commonly involved fentanyl and suxamethonium. Of the respondents, 23.8% indicated that they were aware of a South African standard for colour-coding syringe labels, and 92.9% indicated that they would report anaesthetic errors if a single reporting agency for such events existed. Conclusions. More than a third of participating anaesthetists were involved in a drug error at some stage in their practice. Preventive systems and precautionary measures should be put in place to reduce drug administration errors