118 research outputs found
Red Palm Oil and Its Antioxidant Potential in Reducing Oxidative Stress in HIV/AIDS and TB Patients
Scientific evidence has shown that HIV infection is caused by a retrovirus, the Human
Immunodeficiency Virus (HIV) which is a ribonucleic acid (RNA) virus so designated
because of its genome that encodes an unusual enzyme, reverse transcriptase (RT) that
enables the virus to make copies of its own genome as DNA in its host’s cells (human T4
helper lymphocytes) (Oguntibeju et al., 2008).
The drastic increase in the number of people infected with HIV is not peculiar to a particular
racial group, country or community despite multidimensional efforts which have been
made to combat this scourge (Weiss, 1996; Oguntibeju et al., 2007a). It is reported that the
virus selectively attacks and depletes T-lymphocyte bearing CD4+ cells (T-helper cells)
causing a predisposition to opportunistic infections and malignancies (Weiss, 1996) and
ultimately resulting in Acquired Immunodeficiency Syndrome (AIDS).
The cellular receptors to HIV are cells that express the CD4+ T cell receptor (CD4+ T-cells or
T4-cells) as well as other white blood cells including monocytes and macrophages. Glial
cells in the central nervous system, chromaffin cells in the intestine and Langerhans cells in
mucous membranes and skin that express CD4+ T cell receptors can also be infected (Paxon
et al., 1996). The possibility that there are other cellular targets apart from CD4+T-cells is
proved by the likelihood of neurons that can be infected. This creates the possibility of the
presence of co-receptors in addition to CD4+ T cells to mediate fusion between HIV and its
target cells (Grossman and Heberman, 1997).
Recognition of the CD4+ T-cells by HIV-1 envelope glycoprotein (gp120) to which the virus
binds and enters host cells to initiate rapid replication cycles (Oguntibeju et al., 2007b) depicts
significant cytopathic consequences of HIV infection of CD4+ T-cells (Bartlett, 1998) and is an
important factor in the initiation of HIV infection. The shed virions which are immunogenic,
stimulate B cells to produce humoral antibodies and plasma cells through lymphoid
hyperplasia that ultimately results in decreased number of infected cells as the CD4+ T-cells
migrate through the germinal cells. The depletion in the number of CD4+ T-cells exceeds the
formation of new cells and may maintain this phase for many years resulting in general
disorganization of the lymphoid nodes, loss of lymphoid function and integrity
Die rol van taalvaardigheid in die verband tussen matrieken universiteitsprestasie van swart eerstejaarstudente
This article highlights some of the factors that play a role in the academic success of black first year students who receive non mother-tongue education in English. Students in the Faculties of Economic and Management Sciences, Natural and Agricultural Sciences, as well as the Humanities/Law at the University of the Free State were involved in the study. It was evident that both matric performance and language ability have predictive value. It was also found that the predictive value of these variables differed between the various faculties (which implies that students’ field of study should be taken into account when decisions regarding access with success is made).Key words: language proficiency, matric performance, academic achievement, non mother-tongue education, black first year students.Hierdie artikel werp lig op sommige faktore wat ’n rol speel in die akademiese prestasie van swart eerstejaarstudente wat nie-moedertaalonderrig in Engels ontvang. Studente in die Fakulteite Ekonomiese en Bestuurswetenskappe, Natuur- en Landbouwetenskappe, asook Geesteswetenskappe/Regte aan die Universiteit van die Vrystaat is by die studie betrek. Dit het geblyk dat beide matriekprestasie en taalvaardigheid voorspellingswaarde het. Verder is ook bevind dat die voorspellingswaarde van hierdie veranderlikes verskil tussen verskillende fakulteite (wat impliseer dat studente se studieveld in ag geneem moet word wanneer besluite rakende toelating met sukses geneem word).Sleutelwoorde: taalvaardigheid; matriekprestasie; akademiese prestasie; niemoedertaalonderrig, swart eerstejaarstudente.The article is in Afrikaans
Antifungal activity of epithelial secretions from selected frog species of South Africa
Resistance to antibiotics has been acknowledged as a major global public health problem. The use of antimicrobial peptides to provide alternatives to combat multi-drug antibiotic resistance is beginning to attract increasing attention. The high diversity of amphibian skin peptides renders anurans an important potential source for the discovery of novel pharmacophores. This study aimed to investigate the antifungal activity of skin secretions from selected frogs (Amietia fuscigula, Strongylopus grayi and Xenopus laevis) and one toad (Amietophrynus pantherinus) of the south Western Cape Province of South Africa. Initially, different extraction techniques for the collection of skin secretions were tested and optimized, thereafter the extracts were tested against three fungal species of medical and agricultural importance that is, Candida albicans, Fusarium verticillioides and Aspergillus flavus. Chemical stimulation gave the best yield by mass, and secretions from A. fuscigula showed the best activity with an MIC of 40 μg / ml against C. albicans and 200 μg / ml against A. flavus. In general, C. albicans and A. flavus were the most sensitive while F. verticillioides was the most resistant. From this study it appears that bioprospecting of South African frog species has the potential to yield potential therapeutic lead agents.Key words: Antifungal, African anurans, antimicrobial peptides (AMP), Candida albicans, Aspergillus flavus, bioprospecting, minimum inhibitory concentrations (MIC)
Job satisfaction amongst teachers at special needs schools
The aim of this study was to establish the level of job satisfaction amongst teachers at special schools. Teachers in special schools need to cope with curriculum changes, the administrative duties that come with these changes, and the learners with their diverse needs. Learners with special needs require a specific educational programme and also schools that cater for the needs of learners with emotional, social, neurological or physical problems. The research group consisted of 101 teachers working at six different special schools situated in various parts of the Bloemfontein area, two in the Mangaung area, and four were situated in suburban areas. The group consisted of English- and Afrikaans-speaking teachers of both genders and from different race groups. The data for this study were compiled by means of a short biographical questionnaire and the Minnesota Satisfaction Questionnaire. The results indicated that the teachers experienced an average level of job satisfaction. In addition to this finding, differences were also found in the levels of job satisfaction between different races, but not between genders.Keywords: job satisfaction; Minnesota Satisfaction Questionnaire; South African education; special school
Dietary red palm oil supplementation decreases infarct size in cholesterol fed rats
BACKGROUND AND AIMS:
The effect of red palm oil (RPO) supplementation on infarct size after ischaemia/reperfusion in a cholesterol enriched diet-induced hyperlipidemic animal model has not been reported. Previous studies reported results on the effect of RPO in a normal diet, whilst evidence of protection has been linked to improved functional recovery, prosurvival kinase, anti-apoptosis and NO-cGMP. Therefore, we aimed to investigate the effects of dietary RPO supplementation in a cholesterol-enriched diet-induced hyperlipidemic rat model and to investigate the involvement of matrix metalloproteinase 2 (MMP2) inhibition as a possible mechanism of protection.
MATERIALS AND METHODS:
Male Wistar rats were fed either a standard rat chow diet (Norm) or a 2% cholesterol-enriched diet (Chol) for nine weeks. Additionally, two more groups received the same treatment, however, at the week 4, diet was supplemented with RPO for the last five weeks (Norm+RPO and Chol+RPO), respectively. After the feeding period hearts were isolated, perfused according to Langendorff and subjected to 30 minutes of normothermic global ischaemia followed by two hours of reperfusion. Infarct size was measured by 2,3,5-triphenyltetrazolium chloride staining at the end of reperfusion.
RESULTS:
Cholesterol-enriched diet increased myocardial infarct size from 23.5±3.0% to 37.2±3.6% (p<0.05) when compared to normal diet. RPO supplementation significantly reduced infarct size either in Norm+RPO or in Chol+RPO (to 9.2±1.0% and 26.9±3.0%), respectively. Infarct size in Chol+RPO was comparable to the Norm group. MMP2 activity before ischaemia was significantly reduced in the Chol+RPO group when compared to the Chol group. However, the MMP2 activity of the hearts of the RPO fed rats was significantly increased when compared to the normal diet group after ischaemia.
CONCLUSIONS:
For the first time it was shown that dietary RPO supplementation attenuated the increased susceptibility of the hearts in cholesterol fed rats to ischaemia/reperfusion injury. This was shown by reduced infarct size. For the first time we also show that red palm oil supplementation altered pre-ischaemic levels of MMP-2, which may indicate that myocardial MMP2 may be implicated as a possible role player in RPO mediated protection against ischaemia/reperfusion injury in hearts of cholesterol supplemented rats.This work was supported by a Collaborative Research Grant between Hungary (ZA-35/2006) and South Africa (NRF: 62212) and by grants from the National Office for Research and Technology (Jedlik-NKFP-A1-2006-029, Med-Food, Baross DA-TECH-07-2008-0041, TAMOP-4.2.2-08/1/2008-0013, TAMOP-4.2.1/B-09/1/KONV-2010-0005). T. Csont holds a "János Bolyai Felowship" from the Hungarian Academy of Sciences
Dietary red palm oil supplementation reduces myocardial infarct size in an isolated perfused rat heart model
<p>Abstract</p> <p>Background and Aims</p> <p>Recent studies have shown that dietary red palm oil (RPO) supplementation improves functional recovery following ischaemia/reperfusion in isolated hearts. The main aim of this study was to investigate the effects of dietary RPO supplementation on myocardial infarct size after ischaemia/reperfusion injury. The effects of dietary RPO supplementation on matrix metalloproteinase-2 (MMP2) activation and PKB/Akt phosphorylation were also investigated.</p> <p>Materials and methods</p> <p>Male Wistar rats were divided into three groups and fed a standard rat chow diet (SRC), a SRC supplemented with RPO, or a SRC supplemented with sunflower oil (SFO), for a five week period, respectively. After the feeding period, hearts were excised and perfused on a Langendorff perfusion apparatus. Hearts were subjected to thirty minutes of normothermic global ischaemia and two hours of reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining. Coronary effluent was collected for the first ten minutes of reperfusion in order to measure MMP2 activity by gelatin zymography.</p> <p>Results</p> <p>Dietary RPO-supplementation decreased myocardial infarct size significantly when compared to the SRC-group and the SFO-supplemented group (9.1 ± 1.0% <it>versus </it>30.2 ± 3.9% and 27.1 ± 2.4% respectively). Both dietary RPO- and SFO-supplementation were able to decrease MMP2 activity when compared to the SRC fed group. PKB/Akt phosphorylation (Thr 308) was found to be significantly higher in the dietary RPO supplemented group when compared to the SFO supplemented group at 10 minutes into reperfusion. There was, however, no significant changes observed in ERK phosphorylation.</p> <p>Conclusions</p> <p>Dietary RPO-supplementation was found to be more effective than SFO-supplementation in reducing myocardial infarct size after ischaemia/reperfusion injury. Both dietary RPO and SFO were able to reduce MMP2 activity, which suggests that MMP2 activity does not play a major role in protection offered by RPO. PKB/Akt phosphorylation may, however, be involved in RPO mediated protection.</p
Post-traumatic stress disorder and exposure to violence among Venda and northern Sotho adolescents
In this study, two research questions were posed. In the first place, this study investigated the levels of exposure to violence among the adolescents as a total group (Venda- and Northern Sotho-speaking), as well as the exposure levels of the two ethnic groups.
Opsomming
Twee navorsingsvrae is in hierdie studie gestel. Eerstens het hierdie studie ondersoek ingestel na die vlakke van blootstelling aan geweld onder die groep adolessente as geheel (Venda- en Noord-Sotho-sprekers), asook na die blootstellingsvlakke van die twee etniese groepe.
*Please note: This is a reduced version of the abstract. Please refer to PDF for full text
Inhibition of Akt Attenuates RPO-Induced Cardioprotection
Previous studies have shown that red palm oil (RPO) supplementation protected rat hearts against ischaemia-reperfusion injury. Evidence from these studies suggested that Akt may be partly responsible for the observed protection. The aim of the current study was therefore to prove or refute the involvement of Akt in the RPO-induced cardioprotection by administration of a specific Akt inhibitor (A6730). Male Wistar rats were randomly divided into 2 groups: a control group receiving standard rat chow and an experimental group receiving standard rat chow plus 2 mL RPO for six weeks. Hearts were excised and mounted on the Langendorff perfusion system. Functional recovery was documented. A different set of hearts were freeze-clamped to assess total and phosphorylation status of Akt. Another set of hearts were subjected to the same perfusion conditions with addition of A6730. Hearts from this protocol were freeze-clamped and assessed for total and phospho-Akt. RPO improved functional recovery which was associated with increased phosphorylation of Akt on Ser473 and Thr308 residues. Blockade of Akt phosphorylation caused poor functional recovery. For the first time, these results prove that Akt plays an important role in the RPO-induced cardioprotection
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