A5002740584- Sperm and Testicular Function
- Reproductive Biology and Fertility
- Reproductive Health and Technologies
- Animal Behavior and Reproduction
- Evolution and Paleontology Studies
- Wildlife Ecology and Conservation
- Animal Ecology and Behavior Studies
- Reproductive Physiology in Livestock
- Genetic and phenotypic traits in livestock
- Plant and animal studies
- Effects and risks of endocrine disrupting chemicals
- Avian ecology and behavior
- Ovarian function and disorders
- Primate Behavior and Ecology
- Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities
- Heavy Metal Exposure and Toxicity
- Reproductive biology and impacts on aquatic species
- Pesticide Exposure and Toxicity
- Hypothalamic control of reproductive hormones
- Tardigrade Biology and Ecology
- Evolutionary Psychology and Human Behavior
- Plant Taxonomy and Phylogenetics
- Sexual Differentiation and Disorders
- Animal Diversity and Health Studies
- Aquatic Ecosystems and Biodiversity
University of the Western Cape
2015-2025
Al Khawarizmi International College
2023
Redx Pharma (United Kingdom)
2023
National Zoological Gardens of South Africa
2015-2021
South African National Biodiversity Institute
2020-2021
Scientific Services
2017
Assessment of sperm morphology (including morphometry) is extensively used to determine one the qualities a semen sample and depends on differential staining spermatozoa. A technique should cause as little change dimensions form possible in order reliably evaluate morphometric features sperm. Various techniques have been employed, but only few recommended by World Health Organization are amenable automated morphometry analysis. Our study was aimed at comparing effect three [Papanicolaou...
Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility scientific publications. This even important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition WHO Laboratory Manual Examination Processing Human Semen, International Standard ISO 23162:2021. With these tools, we propose authors should be instructed to follow laboratory methods order publish...
Our study was aimed at exploring a simple procedure to stain differentially the acrosome, head, midpiece, and flagellum of human animal sperm. A further prerequisite that sperm morphology stained samples could be analyzed using automated analysis (ASMA). We developed new staining process SpermBlue fixative stain, which are iso-osmotic in relation semen. The entire fixation processes requires only 25 min. Three main steps required. First, routine smear is made by either semen or diluting...
Since the advent of computer-aided sperm analysis (CASA) some four decades ago, advances in computer technology and software algorithms have helped establish it as a research diagnostic instrument for spermatozoa. Despite mammalian spermatozoa being most diverse cell type known, CASA is great tool that has capacity to provide rapid, reliable objective quantitative assessment quality. This paper provides contemporary findings illustrating scientific commercial applications its ability...
Abstract Background We have studied sperm structure and motility in a eusocial rodent where reproduction is typically restricted to single male behaviourally dominant queen. Males rarely compete for access the queen during her estrus cycle, suggesting little or no role competition. Results Our results revealed an atypical mammalian with spermatozoa from breeding, subordinate disperser males being degenerate almost completely lacking "mammalian phylogenetic stamp". Sperm characterized by...
Motility is an essential characteristic of all flagellated spermatozoa and assessment this parameter one criterion for most semen or sperm evaluations. Computer-aided analysis (CASA) can be used to measure motility more objectively accurately than manual methods, provided that techniques are standardized. Previous studies have shown evaluation subpopulations important analyzing the total motile population alone. We developed a quantitative method determine cut-off values swimming speed...
One known environmental risk factor impacting on human reproduction is heavy metal pollution. Although some metals (e.g., Cu, Se and Zn) have protective effects the male reproductive system in low doses, can accumulate to toxic levels result poor semen quality decreased sperm function. We investigated effect of CuSO4 CdCl2 (10, 50, 100 250 µg/ml or 500 µg/ml) motility vitality by using computer-aided analysis (CASA) two cytotoxicity assays (WST-1 XTT). Several parameters were significantly...
Abstract Contaminants of emerging concern (CECs) pose a significant threat to human and ecosystem health due their persistence, bioaccumulation in higher trophic levels, potential toxicity. While vivo models are commonly used for toxicity screening, developing alternative vitro techniques rapid environmental risk assessment is essential. Spermatozoa, with compartmentalized structure, measurable characteristics sensitivity changes, offer as an model screening. We evaluated the impact selected...
Objectives Although the African elephant (Loxodonta africana) is classified as endangered by International Union for Conservation of Nature (IUCN), in some isolated habitats southern Africa, contraception major interest due to local overpopulation. GnRH vaccination has been promoted a non-invasive contraceptive measure population management overabundant wildlife. We tested efficacy this treatment fertility control bulls. Methods In total, 17 male elephants that were treated with vaccine...
Considering the challenges surrounding causative factors in male infertility, rather than relying on standard semen analysis, assessment of sperm subpopulations and functional characteristics essential for fertilization is paramount. Furthermore, diagnostic value interactions with biological components female reproductive tract may improve our understanding subfertility provide applications assisted techniques. We investigated response two motility (mimicking functionality potentially...
The naked mole-rat (NMR) queen controls reproduction in her eusocial colony by usually selecting one male for and suppressing gametogenesis all other males females. Simplified, polymorphic slow-swimming spermatozoa the NMR seem to have been shaped a low risk of sperm competition. We hypothesize that this unique mammalian social organization has had dramatic influence on testicular features spermatogenesis NMR. structure as well spermatogenic cell types its breeding, subordinate disperser...
Motility is an important criterion in the assessment and quantification of quality ejaculated epididymal sperm samples. Ovine spermatozoa are particularly susceptible to cryodamage, shortening interval from collection cryostorage may potentially minimize negative effects cryopreservation, thereby improving post-thaw viability ram spermatozoa. The use swim-up technique (SUT) quantifying motility well documented, especially for isolation highly motile assisted reproductive purposes. However,...
This study aimed to address the lack of information on quantitative semen and sperm characteristics free-ranging African elephants. Nineteen ejaculates were collected from 12 elephant bulls by means electroejaculation in spring (Season 1, end dry season, n=7) autumn 2, rainy n=12). While most cows are oestrus it is not evident whether quality also improves during this period. Semen samples assessed using computer-aided analysis (CASA), brightfield microscopy transmission electron microscopy....
In order to address the large percentage of unexplained male infertility in humans, more detailed investigations using sperm functional tests are needed identify possible causes for compromised fertility. Since many environmental and lifestyle factors might be contributing infertility, future studies aiming elucidate effect such on fertility will need use appropriate research models. The current study aimed assess effects two heavy metals, namely copper sulphate, cadmium chloride, non-human...
This study aimed at comparing a comprehensive set of functional and structural sperm characteristics between motility fractions correlating results to the standard semen parameters. By grouping related variables, our objective was establish predictive power parameters whether they accurately reflect functionality or merely small within individual fractions.<br />Materials Methods: In this non-invasive experimental study, donor samples (n=55) were separated via<br />double density gradient...