265 research outputs found

    Short communication: Book Review

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    Title: Crime, Violence and Injury in South Africa: 21st Century Solutions for Child SafetyEditors: Ashley van Niekerk, Shahnaaz Suffla and Mohamed SeedatPublication: 2012Publisher: PsySSA PressISBN: 978-1-920014-86-5 (Softcover, 248 pages)Reviewed byMarinda KotzéMedical Research Council-University of South Africa, Safety and Peace Promotion Research Uni

    Ozone autohaemotherapy protects against ketamine hydrochlorideÂź induced liver and muscle damage in baboons

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    Ozone is currently under scrutiny because of various claims of beneficial effect in disease. In order to shed some light on this we assessed the acute and chronic effect of O3 autohaemotherapy (AHT) on liver and muscle damage in baboons. Five percent of the total blood volume of a baboon was treated with O2 and O3. Eleven baboons were acutely treated with an O2/O3 gas mixture containing 20, 40 and 80ĂŹg/ml ozone. Five were treated with pure O2 and three received no treatment to assess the effect of the ketamine hydrochloride anaesthesia. Blood samples were collected before treatment and after 4, 24 and 48 h. Anaesthesia increased aspartate aminotransferase (AST), alanine aminotransferase (ALT) and creatine kinase (CK) levels markedly. O3-AHT had a protective effect, since enzyme levels were lower. O2-AHT had no protective effect on liver and muscle damage. An O2/O3 gas mixture containing 40 ĂŹg/ml O3 was used for chronic O3-AHT (n=6) treatment. The animals were treated at 0, 24 and 48 h. Blood was collected before treatment and again after 4, 24, 28, 48, 52, 72 and 96 h. ALT levels increased and remained elevated. AST levels increased during the four hours following each treatment and remainedelevated. CK levels increased markedly during the four hours following treatment, but decreased after treatment was stopped. The magnitude of changes was small and does not support the view that infusion of ozonated of blood is toxic

    Uptake and transport of novel amphiphilic polyelectrolyte-insulin nanocomplexes by caco-2 cells - towards oral insulin

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    “The original publication is available at www.springerlink.com”. Copyright SpringerPurpose: The influence of polymer architecture on cellular uptake and transport across Caco-2 cells of novel amphiphilic polyelectrolyte-insulin nanocomplexes was investigated. Method: Polyallylamine (PAA) (15 kDa) was grafted with palmitoyl chains (Pa) and subsequently modified with quaternary ammonium moieties (QPa). These two amphiphilic polyelectrolytes (APs) were tagged with rhodamine and their uptake by Caco-2 cells or their polyelectrolyte complexes (PECs) with fluorescein isothiocyanate-insulin (FITC-insulin) uptake were investigated using fluorescence microscopy. The integrity of the monolayer was determined by measurement of transepithelial electrical resistance (TEER). Insulin transport through Caco-2 monolayers was determined during TEER experiments. Result: Pa and insulin were co-localised in the cell membranes while QPa complexes were found within the cytoplasm. QPa complex uptake was not affected by calcium, cytochalasin D or nocodazole. Uptake was reduced by co-incubation with sodium azide, an active transport inhibitor. Both polymers opened tight junctions reversibly where the TEER values fell by up to 35 % within 30 minutes incubation with Caco-2 cells. Insulin transport through monolayers increased when QPa was used (0.27 ngmL-1 of insulin in basal compartment) compared to Pa (0.14 ngmL-1 of insulin in basal compartment) after 2 hours. Conclusion: These APs have been shown to be taken up by Caco-2 cells and reversibly open tight cell junctions. Further work is required to optimise these formulations with a view to maximising their potential to facilitate oral delivery of insulin.Peer reviewe

    Microsatellite markers reveal low genetic differentiation among southern African Camelus dromedarius populations

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    We report new demographic and genetic data on southern African camel (Camelus dromedarius) populations. Results from questionnaires on demography indicated that approximately 476 camels were extant in South Africa, Namibia and Botswana in 2003. We have sampled 234 camels for genetic analysis using a microsatellite marker set consisting of 12 loci. Results indicated little differentiation between camels from southern Africa, the Sudan or an outgroup from the family Camelidae, the alpaca (Lama pacos). Analysis of molecular variance (AMOVA) showed that -0.09% of total variation reside between species, 0.26% between the two southern African camel populations and 99.83% within populations. A coefficient of population differentiation (RST) indicated low levels of differentiation between southern African camel populations, with no specific pattern observed in pair-wise comparisons of 16 populations. An assignment test conformed to known population histories and provided additional support for the hypothesis of low differentiation between populations. There was no evidence of loss of genetic diversity in any individual population. Parentage analysis confirmed the utility of the microsatellite marker set for elucidating uncertain paternity. The results are discussed with reference to the management history of camels in the southern African region and the importance of population and parentage verification in the light of the many historic translocations. Keywords: Camel; genetic differentiation; Camelus dromedaries; genetic variation; microsatellites South African Journal of Animal Sciences Vol. 35 (3) 2005: pp.152-16

    Identifying sequence variation in cation channel sperm associated genes in Cape mountain zebra (Equus zebra zebra)

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    The Cape mountain zebra (Equus zebra zebra) has recovered from near extinction over more than eight decades. While their numbers have increased, populations remain isolated with low genetic diversity. With more than 75 new populations being founded and more than 4800 extant animals, conservation management strategies are being implemented to mitigate risk of losses in genetic diversity and reproductive fitness. One objective is to identify reproductive characteristics that may improve population growth. Cation channel sperm (CatSper) genes play an important role in hyperactivation of sperm during fertilization. Mutations in these genes lead to reduced fertility and even infertility. Ten male zebras were sampled from a group that were translocated in 2016 in order to found a new population. Single nucleotide polymorphisms (SNPs) were identified in three of the CatSper genes (1 - 3). Lack of variation was observed in all exons, with only four SNPs being identified in the intronic regions in close proximity to exons 1, 2, 7, 8, and 9 of CatSper 1. These results may contribute to the pre-identification of males for new founder populations to ensure population growth and viability, and may be a useful tool for selection against low-producing individuals

    Sperm structure and motility in the eusocial naked mole-rat, Heterocephalus glaber: a case of degenerative orthogenesis in the absence of sperm competition?

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    <p>Abstract</p> <p>Background</p> <p>We have studied sperm structure and motility in a eusocial rodent where reproduction is typically restricted to a single male and behaviourally dominant queen. Males rarely compete for access to the queen during her estrus cycle, suggesting little or no role for sperm competition.</p> <p>Results</p> <p>Our results revealed an atypical mammalian sperm structure with spermatozoa from breeding, subordinate and disperser males being degenerate and almost completely lacking a "mammalian phylogenetic stamp". Sperm structure is characterized by extreme polymorphism with most spermatozoa classified as abnormal. Sperm head shapes include round, oval, elongated, lobed, asymmetrical and amorphous. At the ultrastructural level, the sperm head contains condensed to granular chromatin with large open spaces between the chromatin. Nuclear chromatin seems disorganized since chromatin condensation is irregular and extremely inconsistent. The acrosome forms a cap (ca 35%) over the anterior part of the head. A well defined nuclear fossa and neck with five minor sets of banded protein structures are present. The midpiece is poorly organized and contains only 5 to 7 round to oval mitochondria. The flagellar pattern is 9+9+2. A distinct degenerative feature of the tail principal piece is the absence of the fibrous sheath. Only 7% motile spermatozoa were observed which had exceptionally slow swimming speeds.</p> <p>Conclusion</p> <p>In this species, sperm form has simplified and degenerated in many aspects and represents a specialised form of degenerative orthogenesis at the cellular level.</p

    Gene flow and population structure of a solitary top carnivore in a human-dominated landscape.

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    While African leopard populations are considered to be continuous as demonstrated by their high genetic variation, the southernmost leopard population exists in the Eastern and Western Cape, South Africa, where anthropogenic activities may be affecting this population's structure. Little is known about the elusive, last free-roaming top predator in the region and this study is the first to report on leopard population structuring using nuclear DNA. By analyzing 14 microsatellite markers from 40 leopard tissue samples, we aimed to understand the populations' structure, genetic distance, and gene flow (Nm). Our results, based on spatially explicit analysis with Bayesian methods, indicate that leopards in the region exist in a fragmented population structure with lower than expected genetic diversity. Three population groups were identified, between which low to moderate levels of gene flow were observed (Nm 0.5 to 3.6). One subpopulation exhibited low genetic differentiation, suggesting a continuous population structure, while the remaining two appear to be less connected, with low emigration and immigration between these populations. Therefore, genetic barriers are present between the subpopulations, and while leopards in the study region may function as a metapopulation, anthropogenic activities threaten to decrease habitat and movement further. Our results indicate that the leopard population may become isolated within a few generations and suggest that management actions should aim to increase habitat connectivity and reduce human-carnivore conflict. Understanding genetic diversity and connectivity of populations has important conservation implications that can highlight management of priority populations to reverse the effects of human-caused extinctions

    Suicide cases investigated at the state mortuary in Bloemfontein, 2003–2007

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    Background: Up to 8 000 South Africans commit suicide annually. This study aimed to investigate the profile of suicide cases in Bloemfontein and the southern Free State province.Methods: A cross-sectional descriptive study was performed. Suicides in the Bloemfontein and southern Free State areas (Xhariep and Motheo districts) investigated at the state mortuary in Bloemfontein in 2003 to 2007 were included. Data were collected retrospectively by using a specially designed data-capturing form.Results: A total of 469 suicide cases were included in the study. The estimated suicide rate for this part of the Free State province was 10.9/100 000 of the population per year. The majority (82.1%) of the victims were men. In total, 338 (72.1%) of the victims were black, 122 (26.0%) were white, five (1.1%) were coloured and three (0.6%) were Indian. The most common methods were hanging (262; 55.9%), shooting (99; 21.1%) and overdosing on pills (43; 9.2%). Most cases (57.8%) occurred in victims 21 to 40 years of age. Five (1.1%) victims were children younger than 11 years of age, while 12 (2.6%) were older than 65 years. More than half (267 cases; 56.9%) of the suicide victims were unemployed. The majority(43.1%) of suicides occurred in January to April of each year, with the highest incidence (67 cases; 14.3%) in January. Conclusion: The rate of suicide and the profile of victims with regard to the variables investigated corresponded to findings reported from other studies. The information obtained could make a meaningful contribution to suicide-preventionprogrammes.Keywords: suicide; profile; rate; prevention; Free State Provinc

    Differentiation of two South African otter species (Aonyx capensis and Lutra maculicollis) from spraint based on partial CytB primer sets

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    AbstractAccurate species identification based on visual cues can be challenging due to morphological similarities and the cryptic nature of certain species. Thus a more conclusive method of identification is required, namely DNA barcoding. This is the case regarding two South African otter species, Cape Clawless otter (Aonyx capensis) and the spotted necked otter (Lutra maculicollis). Due to the cryptic nature of these animals faecal samples, known as spraints, are the easiest way of confirming the presence of the animal in an area. In this study, we compared results obtained for universal and partial CytB primer sets on collected spraint and tissue control samples. Universal CytB primers revealed a low percentage of amplified otter species from faecal samples (species specific amplification success of 10.9%) whereas, the partial CytB primer set resulted in successful amplification of 45 out of 55 (82%) samples. We were thus able to positively differentiate between the two otter species using the partial CytB primer set developed in this study. The ability to accurately identify species using partial DNA will be beneficial in understanding numerous aspects of the behaviour and ecological importance of animals in their environment
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