Browsing by Author "Oelofse, Andre"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    The association of mercury from dental amalgam with urinary selenium
    (University of the Western Cape, 2017) Aljabo, Rukaia Emhemed; Oelofse, Andre; Osman, Yusuf
    Background: Dental amalgam has been the traditional material for filling cavities in teeth. Mercury (Hg) is a component of dental amalgam, from where it is continuously released and deposited in different tissues, mostly in the brain and the kidneys. Selenium is an important essential element in the human body. Mercury exposure from dental amalgam fillings associated with reduced the levels of selenium. Aims and objectives: The aims of the current study were to investigate the leaching of mercury from dental amalgam fillings and also to investigate the relationship between the leached mercury from dental amalgam fillings and selenium concentrations in the bloodstream. The objective was to determine the mercury from dental amalgam fillings and urinary selenium levels. Methods: Samples were collected from patients attending Tygerberg Oral Health Centre, Cape Town (South Africa). 107 patients who had 1-12 dental amalgam fillings provided the samples of urine, buccal swabs and did the chewing gum test. The samples were analysed by using inductively coupled plasma-mass spectrometry. The data were analysed by IBM (p<0.05) test with an SPSS computer software package version 24. The study involved analyses of samples of urine (n=107), chewing gum and buccal swabs (n= 102). Results: The median urinary concentrations of mercury and selenium in female and male samples were 0.40 μg/L, 0.60 μg/L Hg and 26.29 μg/L, 29.32 μg/L Se respectively. While the median Hg concentrations in chewing gum test and buccal swabs samples in female and male were 2.04 mg/g, 1.89 mg/g Hg and 0.16 μg/L, 0.09 μg/L respectively. Conclusion: The excretion of urinary selenium concentration was influenced by concentration of mercury in urine and age of participants but not affected by concentrations of mercury in buccal swabs, chewing gum and gender of participants.
  • Thumbnail Image
    Item
    Mercury leaching from dental amalgam fillings and its association with urinary zinc
    (University of the Western Cape, 2019) Zanager, Afaf Mohamed; Oelofse, Andre; Osman, Yusuf
    Mercury (Hg) is an example of a toxic metal that is not essential for nutrition. It exists in organic and inorganic forms in seafood and vapour from dental amalgam fillings respectively. Elemental mercury (Hg0) from dental amalgam was the focus of this study. Dental amalgam is one of the most commonly used dental filling materials and has been used for over 150 years. It is composed of Hg0 (approximately 50%) combined with other metals such as copper and zinc (Zn). These fillings give off Hg0 vapour throughout their existence, and is further enhanced by activities such as chewing, grinding of teeth and drinking hot liquids. Mercury consumption can lead to Zn loss or deficiency, and is reported to displace Zn and copper. Several European nations have outlawed the use of amalgam as a restorative material due to controversies regarding its safety in children, women of childbearing age and individuals with renal disease. Moreover, various studies have reported correlations between the number of amalgam fillings and Hg concentration in blood plasma, urine, faeces, saliva and different organs. Blood, urine, and hair mercury levels are used to predict possible health effects that may be caused by the different forms of Hg. Urine Hg is used to test exposure to metallic Hg0 vapour and inorganic Hg forms. This study aimed to evaluate the effects of Hg0 from dental amalgam restorations on the status of Zn in the urine. This was done by determining the concentrations of Hg0 in urine, buccal cells and the oral cavity, and its relationship with urinary Zn concentrations in the same individuals. Samples of urine, buccal tissues, chewing gum and completed questionnaires were collected from the participants (women and men) at the dental clinics in Tygerberg Hospital (TBH), Cape Town. Samples were analyzed using inductively coupled plasma mass spectrometer (ICP-MS). Findings from this study show that there was a correlation between levels of urinary Hg0 and urinary Zn (p=0.02). However, urinary Hg0 did not predict the amount of urinary Zn. Also, no relationship was found between levels of Hg0 in buccal swab or the chew test samples and urinary Zn level. There was a significant difference between females and males in the level of urinary Zn, men had higher levels of Zn excreted in the urine than females (p=0.05). However, there was no significant difference in the level of urinary Hg0 between males and females. The number of fillings (4-7) and age of fillings were significantly associated with urinary Hg0 level (p˂0.05), while smoking ˃15 cigarettes/day increased the level of Hg0 in buccal swab samples (p=0.002). We were not able to demonstrate a causal effect of Hg0 leaching on urinary zinc levels.
  • Thumbnail Image
    Item
    Potential for increasing folate contents of traditional African fermented sorghum gruel (Motoho) using presumptive probiotic lactic acid bacteria
    (Elsevier, 2023) Fayemi, Olanrewaju E.; Akanni, Gabriel B.; Oelofse, Andre
    Folate deficiency is commonly observed in most developing countries. Lactic acid bacteria (LAB) fermentation of cereal-based foods could be an alternative to improving folate intake. This study evaluated the possibility of improving the folate contents of traditional African fermented sorghum gruel (motoho) using indigenous po- tential probiotic LAB. A total of 220 LAB strains isolated from maize gruel were screened for extracellular and intracellular folate production. Strains were further examined for in vitro probiotic characteristics and antimi- crobial activity. Sixteen (16) LAB strains exhibited high production of total folate which ranged between 44 and 180 μg/100 mL with the lowest and highest value in L. plantarum S8 and L. plantarum S49, respectively. Fermentation of sorghum gruel with folate producing probiotic LAB strains for in situ folate production in motoho was determined. The folate contents of sorghum motoho fermented with LAB ranged between 13 and 20 μg/100 mL while the control was below 2.5 μg/100 mL. Indigenous LAB strains from traditional African fermented gruel possess desirable in vitro probiotic properties and ability to produce folates, thus, could be used for natural in situ folate fortification. This study presents a strategy for future application of indigenous probiotic LAB cultures as natural means of fortifying cereal foods with folates.
  • Thumbnail Image
    Item
    The use of ultrasonography for the early detection of cardiovascular risk in adolescents
    (University of the Western Cape, 2022) Shah, Rabia; Oelofse, Andre
    Cardiovascular disease (CVD) is the major cause of mortality and morbidity globally and is the leading cause of death in South Africa second to HIV/AIDS. CVD is on the rise not only in adults but also in children. The presence of modifiable CVD risk factors, such as, smoking, alcohol intake, diet quality, physical activity and obesity, during adolescence increases the chances of having a poor cardiovascular risk profile in adulthood. Therefore, the prevention of CVD in adolescents is important to prevent premature death from CVD. The aim of this study was to assess whether ultrasound measurements of intima-media thickness could indicate CVD risk and an association with modifiable risk factors in adolescent student population.