Physico-chemical attributes of Nguni chevon prepared and preserved using indigenous methods.

Master of Science in Animal and Poultry Science. University of KwaZulu-Natal, Pietermaritzburg, 2018.Abstract available in PDF file

Assessing the Namibian Underwater Cultural Heritage

Namibia is rich in maritime and underwater cultural heritage that historically, has not been fully acknowledged by authorities, as demonstrated by the absence of a comprehensive shipwreck database. Such inaction has led to a host of problems like neglect of shipwrecks, especially those that need urgent conservation leading to either decay by natural processes or plundering by treasure hunters and vandalism because authorities are unaware of such shipwrecks. Second, this thesis investigates the conservation status of these shipwrecks along the Namibian coast, especially onshore shipwrecks that are exposed to weather elements and human accessibility. How decayed or intact are they? Through the identification of natural and human threats to Namibia`s shipwrecks; Namibian heritage authorities have the capacity to effectively initiate programs/projects to conserve shipwrecks in-situ as well as generate revenue through tourism, from such shipwrecks through shipwreck trails, etc. Third, the thesis investigates the approach of heritage authorities in managing Namibia`s underwater cultural heritage? A shipwreck database is a legal requirement for country signatories to the 2001 UNESCO Convention on the Protection of Underwater Cultural Heritage, to which Namibia is a member state. Given this background, relevant questions entail determining: how far has the country gone in legally adopting the 2001 UNESCO convention statutes and what is the role of stakeholdersin protecting shipwrecks, and how well does the current heritage legislature/Act protect shipwrecks? Although historical document analysis, addresses the role shipwreck played in pre-colonial and colonial Namibia, the role of other silent voices (such as African workers on board the ship and or use of the ship in times of war of national resistance i.e., transportation of prisoner of war, shipwrecks as places of memory, etc.) is missing. What is clear from this PhD thesis is that shipwrecks are symbolic of colonial oppression as they have traditionally been seen by many African governments (who were victims of colonial oppression in the past and are reluctant to spend resources to protect shipwreck for this reason). However, what is often ignored is that shipwrecks reflect African contributions to the economic, social and political history of Namibia in a positive way. Thus shipwrecks are possibly a symbol of unity hence the need to protect them by the government of the day.Thesis (PhD)--University of Pretoria, 2020.University of Pretoria Postgraduate Doctoral bursary.Anthropology and ArchaeologyPhD (Archaeology)Unrestricte

Endothelin Antagonism Normalizes VEGF Signaling And Cardiac Function In STZ-Induced Diabetic Rat Hearts

Abnormal alterations in cardiac expression of vascular endothelial growth factor (VEGF) as well as its receptors and impairment in the development of coronary collaterals have recently been reported in diabetic subjects. However, the presence of pharmacological intervention on these defects in diabetes remains unsettled. Here, we studied the effect of endothelin (ET) receptor blockade on cardiac VEGF signaling pathways and cardiac function in Sprague-Dawley rats 5 wk after induction of type I diabetes with streptozotocin (65 mg/kg ip) in comparison with age- matched control rats. After streptozotocin (1 wk), some diabetic rats were treated with the ET receptor antagonist SB-209670 (1 mg/day) for 4 wk. VEGF, its receptors, and its angiogenic signaling molecules [phosphorylated Akt and endothelial nitric-oxide synthase (eNOS)] were analyzed by Western blot, ELISA, real-time PCR, and immu- nohistochemistry, and cardiac function was evaluated by echocardi- ography. Coronary capillary morphology was assessed by lectin and enzymatic double staining. We found significant decreases in cardiac expression of VEGF, its receptors, phosphorylation of Akt and eNOS, and coronary capillary density in diabetic rats compared with controls. Treatment of diabetic rats with SB-209670 reversed these alterations to the control levels and ameliorated impairment of cardiac function. From a molecular point of view, the present study is the first to indicate the potential usefulness of an ET receptor antagonist in the treatment of cardiac dysfunction in type I diabetes

Teenage Fertility in Zambia: Implications for the Future National Population Programme

Abstract Not Provided

Bovine Prenatal Development: A Comparative Study of Ultrasonography and Radiography Techniques

This study was undertaken with the aim of assessing the use of high frequency transducer (7.5 MHz) and a quality ultrasound scanner in the study of in-uterine bovine fetal development i.e. bovine fetal age determination and the ultrasonographic anatomy of the gross tissues and organs of the developing bovine fetus, particularly the stomach compartments, between gestational age 45-90 days. Additionally, ultrasonography was compared to radiography and bone staining techniques, in the study of fetal osteogenesis. The simple regression, polynomial and logarithmic mathematical models were used to examine and analyse in depth, the growth rate and patterns of crown rump length, biparietal diameter and trunk diameter. Each model was tested for fitness of the raw data, precision to predict age and ability to describe the various characteristics of the growth curve of fetal parameters. On average, crown rump length had the fastest growth rate and the least variance, while, trunk diameter had the slowest growth rate and the highest variance of the three fetal parameters analysed. The best mathematical model, out of the three, for crown rump length, in terms of fitness of the raw data and precision to determine fetal age, was the logarithmic model. The linear model was good at giving an overall impression of the average growth rate and steepness of the growth curve. The model with the best fit of the raw data of biparietal diameter and the most precise in determining fetal age was the polynomial model. No major difference in the growth rate and size was noted between the width and depth of the trunk diameter and between sizes of trunk diameter taken at the level of the umbilicus and the stomach This study did not find any major difference of statistical significance between growth curves of embryo transfer fetuses and normal fetuses. The linear model was the simplest of the three models assessed: deriving the age prediction equation and identifying the features of growth that the coefficients represented was easier than with the other two models. It could also be used to ascertain the average growth rate during a given period. However, it could only be used in linear growth curves, usually present in early gestation and not non-linear characteristics seen in a typical growth pattern of later pregnancy. The polynomial model had three coefficients, and hence is more complex to interpret and derive age prediction equations, compared to the other two models. It is, therefore, not, in most cases, a good model to use for the purpose of estimating age. However, it was very good at defining and describing the extent and direction of both linear and curvature features of the growth curves. It did not, however, specify the points at which these curvings begin and end on the growth curve. The two coefficients of logarithmic model are relatively easy to interpret and to derive age prediction equation. It was the most ideal for the purpose of estimating age using fetal dimensions which have typical curvilinear or sigmoid growth curves, because it was able to transform nonlinear raw data into linear and has uniform variations and hence, the least coefficient of variation . No difference, in precision, in determining age of in-uterine bovine fetus between transducers with higher frequency and (7.5 MHz) and those of lower frequencies was found (3.5 and 5.0 MHz.), based on early bovine fetal development. The improvement of precision in fetal aging and a clearer understanding of growth patterns may depend, among other things, on the use of an appropriate age prediction model, at a given age and not so much on the use of transducers of higher frequencies. Sonographic images of almost all the major fetal structures, like the brain, orbit, maxilla, mandible, heart, blood vessels, stomach, hind and forelimbs, were identified by Day 45 of gestation. Sonographic images of the stomach could be identified by Day 39 of gestation, although it was not possible to recognise the differentiation of the stomach compartments until after Day 53 of gestation. The first compartment of the stomach identifiable sonographically was the reticulo-rumen. Differentiation of the rumen into its various sacs became apparent by Day 60 of gestation. Differentiation of the omasum first appeared as a round hyperechogenic structure by Day 53 of pregnancy. The laminae omasi appeared one week later. Other structures of the omasum identified included the esophageal groove and omasi sulci by Day 70 of gestation. The most difficult stomach compartment to identify was the abomasum, because of the close resemblance of its images and its proximity to the intestines. The reticulum was imaged by Day 76 of pregnancy and structures scanned immediate to it were; the liver and diaphragm, cranially, the vestibule of the rumen, caudally and the omasum on the right. The sensitivity of ultrasonography and radiography techniques in detecting the earliest time and chronological order of appearance of the loci of ossification were found to be the same

Postpartum Cervical Repair In Mice: A Morphological Characterization And Potential Role For Angiogenic Factors

The cervix undergoes marked mechanical trauma during delivery of the baby at birth. As such, a timely and complete tissue repair postpartum is necessary to prevent obstetrical complications, such as cervicitis, ectropion, hemorrhage, repeated miscarriages or abortions and possibly pre- term labor and malignancies. However, our knowledge of normal cervical repair is currently incomplete and factors that influence repair are unclear. Here, we characterize the morphological and angiogenic profile of postpartum repair in mice cervix during the first 48 h of postpartum. The key findings presented here are: (1) cervical epithelial folds and size are diminished during the first 48 h of postpartum repair, (2) hypoxic inducible factor 1a, vascular endothelial growth factor (VEGF), and VEGF receptor 1 expression are pronounced early in postpartum cervical repair, and (3) VEGF receptor 2 gene and protein expressions are variable. We conclude that postpartum cervical repair involves gross and microscopic changes and is linked to expression of angiogenic factors. Future studies will assess the suitability of these factors, identified in the present study, as potential markers for determining the phase of postpartum cervical repair in obstetrical complications, such as cervical lacerations

Expression Of Steroidogenic Enzymes And Synthesis Of Sex Steroid Hormones From DHEA In Skeletal Muscle Of Rats

The functional importance of sex steroid hormones (testosterone and estrogens), derived from extragonadal tissues, has recently gained signi?cant appreciation. Circulating dehydroepiandrosterone (DHEA) is peripherally taken up and converted to testosterone by 3-hydrox-ysteroid dehydrogenase (HSD) and 17-HSD, and testosterone in turn is irreversibly converted to estrogens by aromatase cytochrome P-450 (P450arom). Although sex steroid hormones have been implicated in skeletal muscle regulation and adaptation, it is unclear whether skel-etal muscles have a local steroidogenic enzymatic machinery capable of metabolizing circulating DHEA. Thus, here, we investigate whether the three key steroidogenic enzymes (3-HSD, 17-HSD, and P450arom) are present in the skeletal muscle and are capable of generating sex steroid hormones. Consistent with our hypothesis, the present study demonstrates mRNA and protein expression of these enzymes in the skeletal muscle cells of rats both in vivo and in culture (in vitro). Importantly, we also show an intracellular formation of testosterone and estradiol from DHEA or testosterone in cultured muscle cells in a dose-dependent manner. These ?ndings are novel and important in that they provide the ?rst evidence showing that skeletal muscles are capable of locally synthesizing sex steroid hor-mones from circulating DHEA or testosterone

Effects Of Protease Activated Receptor (PAR)2 Blocking Peptide On Endothelin-1 Levels In Kidney Tissues In Endotoxemic Rat Model

Aims: Septic shock, the severe form of sepsis, is associated with development of progressive damage in multiple organs. Kidney can be injured and its functions altered by activation of coagulation, vasoactive-peptide and inflammatory processes in sepsis. Endothelin (ET)-1, a potent vasoconstrictor, is implicated in the pathogenesis of sepsis and its complications. Protease-activated receptors (PARs) are shown to play an important role in the interplay between inflammation and coagulation. We examined the time-dependent alterations of ET-1 and inflammatory cytokine, such as tumor necrosis factor (TNF)-a in kidney tissue in lipopolysaccharide (LPS)-induced septic rat model and the effects of PAR2 blocking peptide on the LPS-induced elevations of renal ET-1 and TNF-a levels.Main methods: Male Wistar rats at 8 weeks of age were administered with either saline solution or LPS at different time points (1, 3, 6 and 10 h). Additionally, we treated LPS-administered rats with PAR2 blocking peptide for 3 h to assess whether blockade of PAR2 has a regulatory role on the ET-1 level in septic kidney. Key fndings: An increase in ET-1 peptide level was observed in kidney tissue after LPS administration time-dependently. Levels of renal TNF-a peaked (around 12-fold) at 1 h of sepsis. Interestingly, PAR2 blocking peptide normalized the LPS-induced elevations of renal ET-1 and TNF-a levels.Significance: The present study reveals a distinct chronological expression of ET-1 and TNF-a in LPS-administered renal tissues and that blockade of PAR2 may play a crucial role in treating renal injury, via normalization of inflammation, coagulation and vaso-active peptide

Expression Of Pituitary Adenylate Cyclase Activating Peptide In The Uterine Cervix, Lumbosacral Dorsal Root Ganglia And Spinal Cord Of Rats During Pregnancy

The uterine cervix is highly innervated by the sensory nerves containing neuropeptides which change during pregnancy and are regulated, in part, by estrogen. These neuropep- tides act as transmitters both in the spinal cord and cervix. The present study was under- taken to determine the expression pattern of the neuropeptide pituitary adenylate cyclase activating peptide (PACAP) in the cervix and its nerves during pregnancy and the influence of estrogen on this expression using immunohistochemistry, radioimmunoassay and RT- PCR. PACAP immunoreactivity was detected in nerves in the cervix, lumbosacral (L6-S1) dorsal root ganglia (DRG) and spinal cord. PACAP immunoreactivity was highest at day 15 of pregnancy in the cervix and dorsal spinal cord, but then decreased over the last trimester of pregnancy. However, levels of PACAP mRNA increased in the L6-S1 DRG at late pregnancy relative to early pregnancy. DRG of ovariectomized rats treated with estrogen showed increased PACAP mRNA synthesis in a dose-related manner, an effect partially blocked by the estrogen receptor (ER) antagonist ICI 182 780. We postulate that synthesis of PACAP in L6-S1 DRG and utilization in the cervix and spinal cord increase over pregnancy and this synthesis is the under influence of the estrogen-ER system. Since PACAP is expressed by sensory nerves and may have roles in nociception and vascular function, collectively, these data are consistent with the hypothesis that sensory nerve-derived neuronal factors innervate the cervix and play a role in cervical ripening

Landiolol Hydrochloride Ameliorates Acute Lung Injury In A Rat Model Of Early Sepsis Through The Suppression Of Elevated Levels Of Pulmonary Endothelin-1

Among the dysfunctions and pathologies associated with sepsis, the underlying molecular mechanisms of sepsis-induced acute lung injury (ALI) are poorly understood. Endothelin (ET)-1, a potent vasoconstrictor and pro-inflammatory peptide, is known to be involved in the pathogenesis of ALI in a rat model of sepsis. Here, we investigated whether landiolol hydrochloride, an ultra-short-acting ß-blocker, plays a crucial role in ameliorating and attenuating LPS-induced ALI through modulation of the ET-1 system. Male Wistar rats at 8 weeks of age were ad-ministered with either saline or lipopolysaccharide (LPS) for three hours (3 h) and some of the LPS-administered rats were continuously treated with landiolol for 3 h. ALI was induced by LPS, including levels of both circulatory and pulmonary TNF-a and IL-6 but [PaO2]was significantly decreased. LPS also induced a signi?cant increase in levels of pulmonary ET-1 and ET-A receptor, but levels of ET-B receptor, which has vasodilating effects, were remarkably diminished. Further, LPS administration upregulated the pulmonary expression of HIF-1a.Finally, the treatment of LPS-administered rats with landiolol for 3 h ameliorated and prevented ALI, normalized the altered levels of pulmonary ET-1 and ET-A receptors. Landiolol also induced significant down-regulation of ET-B receptor in lung tissues in the early hours (phase) of sepsis. However, Landiolol treatment had no effect on the up-regulated inflammatory mediators (TNF-a, IL-6) in both plasma and lung tissues during sepsis, and expression of pulmonary HIF-1a also remained unchanged after landiolol treatment. Collectively, these data led us to conclude that landiolol may ameliorate sepsis-induced ALI via the pulmonary ET system