Medical Technology SA - Volume 23, Issue 1, 2009
Volume 23, Issue 1, 2009
Source: Medical Technology SA 23, pp 4 –7 (2009)More Less
Objectives : Several lines of evidence suggest that Natural Killer (NK) cells have an important role in antiviral defence. Thus, the impairment of NK cell function in the course of HIV infection contributes to a decreased resistance against HIV. Therefore, the interaction between the presence of NK cells and p24 at the placental interface of HIV-1 infected mothers was investigated.
Methods : Evidence of human immunodeficiency virus (HIV) replication was sought in fifty five human placentas obtained from pregnancies complicated by maternal HIV-1 infection. The placentas were examined for p24 antibodies and NK cells (CD56+) using immunohistochemical staining techniques. Viral RNA and CD4+ cell counts were measured in plasma samples obtained from all mothers and babies immediately after delivery.
Results : Presence of p24 antigens was found in 94.6% of placental samples. Natural Killer cell activity was observed in 98.3% of samples. There was no statistically significant correlation between number of NK cells and vertical transmission (p = 0.145). However, the risk for vertical transmission was increased 3.4 times more if NK cell values were low [OR = 3.424 (95% CI 0.65-17.89)].
Conclusion : The presence of p24 in placental tissue was not influenced by maternal viral load. Low NK cell values increased the risk for vertical transmission.
Source: Medical Technology SA 23, pp 8 –10 (2009)More Less
Cumene hydroperoxide (cHP) and t-butyl hydroperoxide (tbHP) have been implicated in lipid peroxidation of sperm plasma membranes, DNA damage and apoptosis. This study aimed to investigate the in vivo effects of these hydroxides on rat sperm apoptosis, specifically caspase 3/7, and the possible protective effect offered by red palm oil (RPO). Rats (n=54) were divided into three groups receiving either standard rat chow (SRC; n=18), 2mL RPO (in 25g SRC/day; n=18) and 4mL RPO (in 25g SRC/day; n=18), respectively. Furthermore, each group was divided into three subgroups (n=6). These subgroups consisted of rats injected with saline (control), 10µM cHP or 20µM tbHP. Rats fed with SRC and injected with 10µM of cHP or 20µM of tbHP showed a significant increase (P<0.05) in caspase 3/7 activity compared to the control group (injected with 0.5mL saline). On the other hand, animals fed with SRC in addition to 2mL or 4mL of RPO and injected with 10µM of cHP or 20µM of tbHP showed a significant decrease (P<0.05) in the production of caspase 3/7 activity compared to those fed with SRC only. It can be concluded that RPO possibly reduces caspase 3/7 activity, thereby, inhibiting apoptosis caused in rat sperm by the in vivo induction of hydroperoxide.
Source: Medical Technology SA 23, pp 11 –13 (2009)More Less
Human Geophagia, a phenomenon widely practised especially in Africa, is the craving and deliberate ingestion of clayey soils. It is frequently practised by women and children to relieve hunger, supply nutritional deficiencies or as folk medicine. Geophagic individuals are very selective in the type of clayey soil they consume, where it is obtained, and its physical state; as well as its colour, smell and texture. Though clayey soils are medicinal, they could equally be risky and hazardous to human health. Reports have associated geophagia with iron deficiency leading to anaemia, infestation with geohelminths, and abrasion of the gastro-intestines. This overview brings awareness on clayey soils consumed and throws light on the human health associated effects.
Red blood cell folate stability study : stability of whole blood prior to haemolysate preparation and stability of the haemolysate at various temperaturesSource: Medical Technology SA 23, pp 14 –16 (2009)More Less
Introduction : Folate is an essential vitamin vital for normal cell growth and DNA synthesis. A folate deficiency can lead to megaloblastic anaemia and severe neurological problems. Samples received at our laboratory often have long transit times as they are sent from peripheral clinics; therefore we determined sample stability. An accreditation non-conformance for the storage temperature of prepared haemolysate led to this haemolysate stability study.
Methods : Fasting blood samples were drawn from 40 healthy volunteers. Baseline RBC folate was performed in duplicate on each sample. Half the whole blood was then stored at various temperatures for 72 hours prior to haemolysate formation and RBC folate was determined every 24 hours. The other half was haemolysed, the haemolysate stored at various temperatures and analysed at 4-hourly intervals for 12 hours.
Results: Using the 15% acceptable assay imprecision allowed for RBC folate determination, it was found that whole blood was stable at room temperature unprotected from light for 72 hours. Taking the manufacturers 10% allowable degradation of the haemolysate and 15% acceptable assay imprecision into consideration, haemolysates may be stored for up to 12 hours at -20°C.
Conclusions : Samples transported from distant clinics for RBC determination are stable for up to 72 hours at room temperature even if unprotected from light. Haemolysates prepared for RBC folate determination may be stored at -20°C.
Source: Medical Technology SA 23, pp 17 –21 (2009)More Less
Background : Mother-to-child transmission (MTCT) of HIV can occur perinatally and postnatally. Mechanisms of antepartum and intrapartum transmission of HIV include transfer of the virus via maternal blood and transplacental exposure. Understanding the mechanisms of transfer can lead to identification of risk factors in vertical transmission
Study Design and Methods: This study aims to demonstrate the relationship between the viral load and CD4+ cell counts of HIV-1 infected mothers and their babies at birth. Peripheral blood samples were obtained from fifty five mothers at delivery and their babies within the first 48 hours of birth. HIV viral load using Roché Amplicor Version 1.5, Germany and CD4+ cell counts were performed on plasma and blood samples obtained from all mother-baby pairs in the study.
Results : The pooled rate of transmission from HIV-1 infected mothers to their babies was 0.27 (95% CI 0.15-0.39). Maternal viraemia was significantly associated with transmission of infection to babies (p = 0.047). The odds ratio indicated that for every 1 log increase in maternal viral load the babies were 3.1 times more likely to acquire the infection (Exp (B) = 3.137 (95% CI, 1.015-9.696). No significant association was observed between the viral load of mothers and their CD4+ cell counts (p = 0.134).
Conclusion: The findings suggested that maternal HIV-1 RNA is a strong predictor of risk in untreated HIV-1 positive mothers and is a valuable prognostic marker for mother-to-child transmission.
Source: Medical Technology SA 23, pp 22 –23 (2009)More Less
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