Effects of Momordica balsamina methanolic extract on cardiovascular and haematological function in streptozotocin-induced diabetic rats : effects on selected markers.

Masters Degree. University of KwaZulu-Natal, Durban.Background The hyperglycaemia-induced haemanetic changes reduces the oxygen-carrying capacity of erythrocytes, thus aggravating cardiovascular disorders in diabetic patients. The conventional therapies have been shown to be associated with the progression of haematological and cardiovascular dysfunction, which may not be favorable for patients with congestive heart failure. We have previously shown the anti-hyperglycaemic and antioxidant properties of Momordica balsamina (MB) methanolic extract which may be of benefit in alleviating cardiovascular disorders, thus providing an effective alternative therapy. The current study therefore, investigated the short-term effects of MB methanolic extract on cardiovascular and haematological function in streptozotocin-induced diabetic rats. Methods Briefly, air-dried MB leaves were extracted with methanol to yield a methanolic extract. STZ-induced diabetic rats were divided into untreated and treated groups with insulin (170 μg kg-1 s.c.) and metformin (500 mg kg-1 p.o.) as standard drugs. MB (250 mg kg-1 p.o.) was administered twice daily for 5 weeks. Blood glucose concentration, body weight and blood pressure were monitored weekly for 5 weeks. Terminally, animals were sacrificed after which blood, heart and kidneys were collected for haematological and biochemical analysis. Histological analysis was also performed on the hearts. Results MB significantly decreased blood glucose concentration from week 3-5 by comparison with diabetic untreated animals. Treatment with MB reduced oxidative stress in the plasma, kidney and heart while improving their antioxidant status compared with untreated diabetic animals. This was associated with increased EPO secretion by the kidneys thus improving RBC production and haemoglobin concentrations. MB moderately increased erythrocyte indices: mean cell volume (MCV), mean cell haemoglobin concentration (MCHC) and mean corpuscular haemoglobin (MCH) by comparison with untreated diabetic animals. MB ameliorated heart hypertrophy and decreased CRP, CT-I and Ang-II concentrations by comparison with untreated diabetic animals. MB also decreased MAP by comparison with untreated diabetic animals.Conclusion MB administration protects against hyperglycaemia-induced cardiovascular and haematological changes by attenuating hyperglycaemia, oxidative stress in both the kidney and heart tissues of STZ-induced diabetic rats, which may reduce the risks of cardiac myopathology complications in diabetes mellitus

Home ownership in the gap-housing market in South Africa

The access to adequate housing is a constitutional right, in terms of Section 26 (1) of the Constitution of the Republic of South Africa, Act 108 of 1996. Access to housing in South Africa is still an ideal and not a reality. The increase in housing prices reduces affordability, which creates a barrier to the housing market for South Africans to fully participate. The South African housing market is divided, based on the affordability of households, with a gap within the property market. The gap-housing market is a market, which does not receive a government subsidy; and furthermore, it does not qualify for bond finance by the private financial institutions. The gap-housing market includes households that earn between R3,500 to R15,000 per month for residential properties valued between R116,703 to R483,481. The problem is a lack of supply in the gap-housing market to meet the demand; and this is also affected by the poor performance of the subsidy-housing market. The gap-housing market is not traded adequately, due to a lack of supply caused by stricter lending criteria from the banks. The study was conducted by means of reviewing the related literature and by an empirical study. A survey was conducted using the quantitative approach through a distribution of research questionnaires to different organizations within the judgement sample population. The objective of the study is to review the gap-housing market and to make recommendations. The descriptive survey was conducted among specialists that are participating in the South African housing market. The findings of the study suggest that there is a relationship between incentive and participation, as well as a relationship between participation – with access, supply and trading in the gap-housing market. This study will contribute to the South African housing market body of knowledge – by addressing the problem of a gap within the housing market

Nitric oxide (NO) regulates the expression of single-domain cystatins in glycine max (soybean)

Plant cystatins inhibit cysteine proteases and are important in regulating plant development and plant responses to biotic and abiotic stress. Furthermore, nitric oxide plays a signaling role in regulating plant responses to developmental processes, biotic and abiotic stress. With the aim of determining if nitric oxide is involved in the regulation of the expression of single-domain cystatins, we have identified single-domain cystatin genes in soybean (Glycine max cv. PAN626) on the basis of sequence homology to a nitric oxide-inducible cystatin (AtCYS1, At5g12140) from Arabidopsis thaliana. Analysis of the expression of the four cystatin genes revealed that transcript levels of these cystatins are altered by exogenously applied nitric oxide and a nitric oxide synthase inhibitor. Altered expression of these cystatins by nitric oxide and the nitric oxide synthase inhibitor implies that changes in cellular nitric oxide content, which have previously been shown to occur during development and/or biotic and abiotic stress, influence soybean physiological processes that are regulated by cysteine proteases. Recombinant protein expression of one of the cystatins (as a glutathione-S-transferase fusion protein) showed that it has inhibitory activity against the model cysteine protease papain but not the model serine protease trypsin and that it inhibits caspase-like activity in soybean nodule extracts. This serves as evidence that these four plant cystatins are functional cysteine protease inhibitors because of their high degree of primary sequence identity. It also indicates that the single-domain cystatins regulate caspase-like activity, which is known to participate in plant responses to biotic and abiotic stress. We thus conclude that nitric oxide and nitric oxide synthase-like activity regulate the expression of these cystatins, thus influencing soybean caspase-like activity. We also propose a role for this nitric oxide-mediated regulation of cystatin gene expression in the mediation of developmental processes and responses to abiotic stress in soybean.Web of Scienc

Response of soybean nodules to exogenously applied caffeic acid during NaCl-induced salinity

AbstractCaffeic acid acts as an antioxidant to scavenge reactive oxygen species, but its influence on plant responses to abiotic stresses is only partially understood. Here, we investigated the influence of exogenously applied caffeic acid on soybean during NaCl-induced salinity. Exogenously applied caffeic acid reduced the deleterious effects of salinity stress on soybean plants and increased nitric oxide content in root nodules and this corresponded with elevated cyclic guanosine monophosphate content in the nodules. Salinity stress reduced nodule legheamoglobin content and nitrogenase activity whereas exogenous application of caffeic acid to NaCl-treated plants reversed these negative effects of NaCl on legheamoglobin content and nitrogenase activity. Hydrogen peroxide (H2O2) and malondialdehyde contents in soybean root nodules from plants exposed to salinity were lower when these plants were supplemented with exogenous caffeic acid than when no caffeic acid was supplemented. We suggest that caffeic acid enhances nitric oxide biosynthesis, which possibly acts to reduce salinity-induced oxidative stress through a mechanism that involves nitric oxide signaling coupled with cyclic guanosine monophosphate-mediated signaling to scavenge reactive oxygen species.The ability of caffeic acid to reduce salinity-induced oxidative stress via regulation of nitric oxide signaling has implications for genetic improvement of crop to enhance their tolerance against salinity. This can be achieved by identifying genes, namely genes encoding p-coumarate 3-hydroxylases, responsible for the biosynthesis of caffeic acid and modulating their expression under salinity. Such improvement would impact positively on food security as it would limit the detrimental effects of salinity of crop productivity

Characterization of two Arabidopsis thaliana genes with roles in plant homeostasis

Philosophiae Doctor - PhDPlants are continuously exposed to varying conditions in their environment, to which they have to adapt by manipulating various cellular processes. Environmental (abiotic) and pathogen (biotic) stress are challenges against which plants have to defend themselves. Many plant responses to stress stimuli are a result of cellular processes that can be divided into three sequential steps; namely signal perception, signal transduction m1d execution of a response. Stress signal perception is, in most of these cases, facilitated by cell surface or intracellular receptors that act to recognize molecules presented to the cell. In several cases, hormones are synthesized in response to stress signals and in turn these hormones are perceived by cellular receptors that trigger signal transduction cascades. Propagation of signal transduction cascades is a complex process that results from activation of various signaling molecules within the cell. Second messengers like calcium (Ca2+) and guanosine 3', 5'-cyclic monophosphate (cGMP) play a vital role in mediating many signal transduction processes. The result of these signal transduction cascades is, in most instances, expression of genes that contribute to the plant's ability to cope with the challenges presented to it. Plant natriuretic peptides (PNPs) are novel plant hormones that regulate water and salt homeostasis via cGMP-dependent signaling pathways that involve deployment of Ca2+. The aim of this study is to partially characterize a PNP and a guanylyl cyclase, both from Arabidopsis thaliana. Guanylyl cyclases synthesize cGMP from the hydrolysis of guanosine 5' -triphosphate (GTP) in the cell. The study also aims to investigate the effect of drought and salinity on cGMP levels in plants, using sorbitol to mimic the osmolarity/dehydration effect of drought and NaCl as a source of salinity stress and thus link NaCl and sorbitol responses to both AtPNP-A and cGMP up-regulation

Sexual socialisation: young adult women storying how sexual activities were discussed in South African cultural contexts

Epidemics such as HIV/AIDS, unplanned pregnancy, gender-based violence and homophobia, in South Africa, have focused research on how young people learn about sex. This research has often focused on young girls from risk-saturated areas, and specific agents of socialisation, where they might learn about sex, such as parents, life orientation at schools, peers, media, and traditional cultural approaches. Using a narrative theoretical framework, through memory work, this study explored how black young adult women friends – who were university students – experienced forms of sexual socialisation, through various communication in South African cultural contexts. Findings from the thematic narrative analysis that was conducted demonstrated that sexual socialisation is a complex life-long process. This takes place through a collision of contradictory messages, from different agents of socialisation, in different cultural contexts. Themes were identified and organised to tell an overall sexual socialisation story that progressed through time, moving from a stage of perceived innocent oblivion, mixed messages in primary and high school, “liberal” university stories and the current stage of reauthoring stories.Thesis (MA) -- Faculty of Humanities, Psychology, 202

Sexual socialisation: young adult women storying how sexual activities were discussed in South African cultural contexts

Epidemics such as HIV/AIDS, unplanned pregnancy, gender-based violence and homophobia, in South Africa, have focused research on how young people learn about sex. This research has often focused on young girls from risk-saturated areas, and specific agents of socialisation, where they might learn about sex, such as parents, life orientation at schools, peers, media, and traditional cultural approaches. Using a narrative theoretical framework, through memory work, this study explored how black young adult women friends – who were university students – experienced forms of sexual socialisation, through various communication in South African cultural contexts. Findings from the thematic narrative analysis that was conducted demonstrated that sexual socialisation is a complex life-long process. This takes place through a collision of contradictory messages, from different agents of socialisation, in different cultural contexts. Themes were identified and organised to tell an overall sexual socialisation story that progressed through time, moving from a stage of perceived innocent oblivion, mixed messages in primary and high school, “liberal” university stories and the current stage of reauthoring stories.Thesis (MA) -- Faculty of Humanities, Psychology, 202

Evaluating the effect of academic literacy intervention programme on the SATAP English scores of first year students at a university in the Eastern Cape Province, South Africa

The effect of the academic literacy intervention programme on the SATAP English scores was evaluated. This study begins as a longitudinal study in the Faculty of Science, Engineering and Technology (FSET). 120 subjects from the Electrical, Civil, Building and Mechanical departments in the FSET were randomly selected to serve as an experimental group. The research design employed a quantitative methodology. Data was collected using the Standardised Assessment Tests for Access and Placement (SATAP) English Test. The test was administered to the experimental group as a pre- test and post-test measure at the beginning of the year and at the end of the year. The SPSS statistical programme with frequency tables and graphs was utilised to analyse the data obtained. The results indicated that the difference between the pre-test scores and the post-test scores was statistically significant. The post-test scores were significantly higher than the pre-test ones. It was concluded that the academic literacy intervention programme was effective in increasing the SATAP scores and therefore addressed some of the language needs of students.Language Education Arts and CultureM. Ed. (Adult Education

Identification of a novel protein with guanylyl cyclase activity in Arabidopsis thaliana

Guanylyl cyclases (GCs) catalyze the formation of the second messenger guanosine 3 ,5 -cyclic monophos- phate (cGMP) from guanosine 5 -triphosphate (GTP). While many cGMP-mediated processes in plants have been reported, no plant molecule with GC activity has been identified. When the Arabidopsis thaliana genome is queried with GC sequences from cyanobacteria, lower and higher eukaryotes no unassigned proteins with sig- nificant similarity are found. However, a motif search of the A. thaliana genome based on conserved and func- tionally assigned amino acids in the catalytic center of annotated GCs returns one candidate that also contains the adjacent glycine-rich domain typical for GCs