Note on the effect of ageing on the neutral salt and acid soluble collagen from the intramuscular connective tissue of various species

The neutral salt soluble (NSSC) and acid soluble collagens (ASC) from the intramuscular connective tissue of various species were extracted, purified and studied by optical rotatory dispersion, viscosity and polyacrylamide gel electrophoresis. No significant changes in the quantity of such soluble fractions, in the optical rotatory dispersion or in viscosity of the purified samples were observed during two weeks storage at 1 °C. Electrophoretical analysis suggested a decrease in the relative concentration of the α chains of the ASC. It was concluded that if there are changes in the NSSC or ASC of muscle during ageing these are not detected by the techniques employed.     

Reactivity of glycerol in intermediate moisture meats

Non-enzymic browning (NEB) reactions between glycerol and some of the amino acids present in meat have been observed at 38 and 65°C; l-lysine is the most reactive of the amino acids studied and l-cysteine and l-arginine the least. These NEB reactions also occur between glycerol and proteins (gelatin and casein). The reactions are not unique to glycerol as other polyhydric alcohols also form brown pigments with lysine. On prolonged air storage at 65°C glycerol itself undergoes mild oxidation, ultimately yielding a brown solution.     

Improved methodology for the electrophoretic determination of horse meat in heated foodstuffs

Using linear gradient polyacrylamide gel electrophoresis to separate constituent proteins, horse meat could be clearly distinguished from beef even after heating for 20 min at up to 120°C.     

Digital broadcasting – Challenges and opportunities for European community radio broadcasters

Access to broadcast infrastructure is vital for community radio services, however the switch-over from analogue to digital, as envisaged by European policy-makers, creates challenges for such stations. In this article, we will set out the general environment within which the transition to digital is occurring, illustrate the current state of the digital migration debate, identify potential difficulties for community radios, but also highlight opportunities that digital technologies may provide.     

Making of targets for physics experiments at iThemba LABS

This paper discusses the development of the new target laboratory intended for use of the experimental nuclear physics group at iThemba LABS. The types of targets relevant to the requirements of the instruments utilized during experiments are discussed in detail. In addition, an overview of new target developments, laboratory setup including equipments status and future prospects are also given.     

Interferon-alpha gene therapy for cancer: retroviral transduction of fibroblasts and particle-mediated transfection of tumor cells are both effective strategies for gene delivery in murine tumor models

Stable transfection of tumor cells with IFN-alpha genes has been shown to result in abrogation of tumor establishment and induction of antitumor immunity. However, strategies suitable for the clinical application of IFN-alpha gene therapy for cancer have not been reported. In this study, we investigated two gene delivery systems capable of mediating the local paracrine production of high levels of biologically active IFN-alpha in murine tumor models: retroviral transduction of fibroblasts and particle-mediated transfection of tumor cells. In spite of the antiproliferative effects of IFN-alpha, it was possible to obtain stable retroviral producer cell lines and transduce a variety of murine tumor cells including syngeneic fibroblasts to stably secrete 2000-5000 U (40-100 ng) murine IFN-alpha/10(6) cells/24 h. IFN-alpha transduction of tumor cells abrogated tumorigenicity in establishment models and induced antitumor immunity in several murine tumor model systems. Importantly, IFN-alpha gene delivery using retrovirally transduced syngeneic fibroblasts was capable of suppressing the establishment of the poorly immunogenic TS/A mouse mammary adenocarcinoma and induced antitumor immunity. Particle mediated transient transfection of tumor cells using the gene gun led to the production of up to 20,000 U IFN-alpha/10(6) cells during the first 24 h and proved to be equally effective in suppressing establishment of TS/A adenocarcinoma and inducing antitumor immunity. These results suggest that retroviral transduction of autologous fibroblasts can serve as an effective gene delivery method for IFN-alpha gene therapy of cancer. Particle-mediated transfection of freshly isolated tumor cells may represent a clinically attractive alternative approach for nonviral gene delivery. Both strategies circumvent the difficulties in routinely establishing primary tumor cell lines from the vast majority of human cancers.