Medical Technology SA - Volume 24, Issue 1, 2010
Volume 24, Issue 1, 2010
Effects of methotrexate on antioxidant enzyme status in a rodent model : peer reviewed original articleSource: Medical Technology SA 24, pp 4 –9 (2010)More Less
Methotrexate (MTX), a folic acid antagonist is widely used as a cytotoxic chemotherapeutic agent, however its associated hepatotoxicity is considered to be a major clinical side-effect. The aim of this study was to investigate the status of antioxidant enzymes during oxidative stress in liver homogenates of rats subjected to oral methotrexate administration. A total of forty two, 7-week old male Wistar rats with mean weight of 172 g, divided into two groups were used. The first group, control (n = 6), were fed only standard rat chow as their diet and water ad libitum. The second group (n = 36, subdivided into six sub-groups), fed on the same rat chow diet, received orally administered methotrexate at a dose of 13.4 mg/kg at weekly intervals for 6 consecutive weeks. Thiobarbituric acid reactive substance (TBARS) levels and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) were subsequently determined spectrophotometrically on liver homogenates of all animals.
It was found that methotrexate caused a significant increase in TBARS levels (an important marker of lipid peroxidation) in the methotrexate administered groups when compared with the control group (P < 0.05). The activities of superoxide dismutase, catalase, and glutathione reductase were significantly decreased in the methotrexate groups at weeks 2, 3, 4, 5 and 6 when compared with the control group (P < 0.05). The results therefore indicate that methotrexate causes oxidative stress by reducing the activities and consequently the effectiveness of the antioxidant enzyme defense system.
Author Pierre J.T. De VilliersSource: Medical Technology SA 24 (2010)More Less
A professional society is usually a non-profit organization, seeking to further a particular profession (and its body of knowledge), the interests of individuals engaged in that profession, and the public interest. They generally strive to achieve a balance between two often conflicting mandates, namely the interest of the profession (and the individuals within that profession), and the public interest.
The impact of collection tube fill volume on international normalized ratio : peer reviewed original articleSource: Medical Technology SA 24, pp 11 –16 (2010)More Less
Introduction: Pre-analytical variability currently represents the most important source of errors that can lead to inaccurate patient results in monitoring of patients being treated with oral anticoagulant therapy. The volume of blood collected is critical for accurate coagulation results. The National Committee for Clinical Laboratory Standards (NCCLS) recommends a ratio of blood to anticoagulant volume of 9:1. However, investigators have published reports which suggest that a lower ratio may be acceptable. Unfortunately the recommendations of these reports are inconsistent.
Aim: The aim of this study was to determine the impact of tube fill volume on INR values both in healthy subjects and patients receiving oral anticoagulation therapy.
Methods: INR values were obtained by processing coagulation specimens containing different volumes of whole blood. The study group included 30 patients taking oral anticoagulation therapy and 15 healthy volunteers. Respectively 2.5ml, 3 ml, 3.5 ml, 4 ml and 4.5 ml of whole blood was drawn into tubes containing a fixed volume of 3.2% (0.109M) sodium citrate.
Results: The INR values increased as total tube fill volumes decreased for both groups but this finding did not reach statistical significance in either group for the tube fill volumes studied.
Conclusion: For blood specimens collected in 3.2% citrate anticoagulant, a total tube fill volume of greater than 56% yielded reliable INR results
Author W.J. MauleSource: Medical Technology SA 24, pp 17 –24 (2010)More Less
Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune connective tissue disorder, which has variable clinical manifestations that range from mild to life-threatening. Young women between their late teens and early 40s have a much higher prevalence in developing SLE, with a female to male ratio of 9:1. In the United States (U.S.) for example, Lawrence et al. reported that SLE appeared to be more common in black women than in other population groups. One U.S. retrospective study of patient medical records, by McCarty et al. found that the disease was diagnosed 23 times more often in black women. Certain ethnic groups also appear to show a higher prevalence, such as people with Afro - Caribbean or African origin.
The identification of a double heterozygote Hb S/β0 thalassaemia in a patient using high performance liquid chromatography (HPLC) : peer reviewed case studySource: Medical Technology SA 24, pp 25 –29 (2010)More Less
Beta thalassaemia is rare in Africa except for pockets in West Africa, Liberia and Northern Africa whilst sickle cell disease is common in tropical Africa. Hb S/β thalassaemia is a double heterozygous condition occurring in parts of Africa, the Mediterranean - Greece and Italy, the Middle East and in parts of India. We describe a black family from Giyani in the Limpopo Province, South Africa in whom we identified Hb S/β0 thalassaemia in one of the children. Use was made of high performance liquid chromatography (HPLC) technique from Bio-Rad Laboratories, Germany, for the determination of the abnormal haemoglobins. We believe there may be many more such cases seen, due to the enormous influx of people across South Africa's borders.