Kristian Leisegang

Kristian Leisegang

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

The organizations/institutes from the scholar's latest article


Kristian Leisegang has a total of 254 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Small Supernumerary Marker Chromosome (sSMC) 15 in Male Primary Infertility: A Case Study

    by Filomena Mottola, Renata Finelli, Veronica Feola, Kristian Leisegang, Lucia Rocco

    This case report describes a 39‐year‐old phenotypically normal male patient of a married couple with primary infertility presenting as candidates for assisted reproductive techniques. The medical history of the couple is unremarkable, with both partners phenotypically normal. Semen analysis revealed oligoasthenzoospermia (OAT), 15% sperm DNA fragmentation and 4% aneuploidies in the sperm nuclei. Genetic analysis showed no Y chromosome of cystic fibrosis transmembrane conductance regulator gene mutations. Karyotype analysis in the male partner revealed a small supernumerary marker chromosome (sSMC) derived from chromosome 15, specifically inverted and duplicated (inv dup(15)) corresponding to the 15q11.2 region but lacking the Prader‐Willi/Angelman syndrome critical region (PWACR). Further investigations revealed that 35% of the patient’s spermatozoa carried the sSMC(15). This case study highlights the potential association between the presence of an inv dup(15) sSMC, without the involvement of the PWACR, and male infertility. sSMC(15) may disrupt spermatogenesis and contribute to oligoasthenozoospermia in males with primary infertility. Further research into the association of mechanism mechanisms of male infertility related to the 15q11.2 region is warranted.


  • Open Access

    Aqueous extractions of Mondia whitei root improve human sperm function in vitro

    by Maureen Bilinga Tendwa, Aqeel Morris, Chinyerum Silvia Opuwari, Kristian Leisegang, Renata Finelli, Cătălina Zenoaga-Barbăroșie, Ralf Henkel


  • Open Access

    The Effect of Aqueous Lessertia frutescens Extract on TM3 Leydig Cells Exposed to TNF-α in vitro

    by Kristian Leisegang, Renata Finelli, Ralf Henkel, Cătălina Zenoaga-Barbăroșie

    Background: Extractions of Lessertia frutescens (Lf) are shown to have immune modulation, anti-inflammatory and antioxidant properties. However, Lf is also cytotoxic, antiproliferative, and pro-apoptotic in vitro. Furthermore, Lf extractions may influence steroidogenesis. Nevertheless, the impact on Leydig cell function has not previously been investigated. As tumor necrosis factor-alpha (TNF-α) is known to cause Leydig cell dysfunction under inflammatory conditions, it is further proposed that Lf extracts may protect against the negative impact of TNF-α on Leydig cells. The aim of the study was to investigate the effect of an aqueous Lessertia frutescens extract (LFE) on Leydig cells exposed to TNF-αin vitro. Methods: Human chorionic gonadotrophin-stimulated TM3 Leydig cells were exposed for 24 h to (a) TNF-α (0.1, 1, 10, 100 ng/mL), (b) LFE (0.01, 0.1, 1, 10, 100 ng/mL), and (c) co-exposure to 10 ng/mL TNF-α and LFE (0.01, 0.1, 1, 10, 100 ng/mL). We analyzed cell viability, cytotoxicity, caspase 3/7 activation, testosterone concentration, and intracellular superoxide. Results: TNF-α exposure decreased cell viability, increased cytotoxicity, and caspase 3/7, with no significant effect on intracellular superoxide in TM3 Leydig cells. When LFE concentrations of 0.01–10 ng/mL were tested, we observed improved vitality and reduced levels of caspase 3/7. At 100 ng/mL, LFE decreased viability and increased cytotoxicity and caspase 3/7. However, LFE did not affect intracellular superoxide. Furthermore, LFE protected against 10 ng/mL TNF-α-induced cytotoxicity and apoptosis, except at the highest concentration. LFE alone and in co-culture with 10 ng/mL TNF-α increased testosterone at high concentrations. Conclusions: In our TM3 Leydig cell model, LFE protected against TNF-α-induced cytotoxicity and early apoptosis, except at the highest experimental concentrations, where it was cytotoxic. These effects were not mediated through a change in intracellular superoxide. Although further investigations are warranted, aqueous LFE may protect against TNF-α-induced Leydig cell dysfunction.


  • Open Access

    Traditional, Complementary and Alternative Medicines in the Treatment of Ejaculatory Disorders: A Systematic Review

    by Kristian Leisegang, Chinyerum Sylvia Opuwari, Faith Moichela, Renata Finelli

    Background and Objectives: Ejaculatory dysfunction (EjD) is a common male sexual disorder that includes premature ejaculation, delayed ejaculation, retrograde ejaculation, and anejaculation. Although psychological and pharmacological treatments are available, traditional, complementary, and alternative medicine (TCAM) is reportedly used. However, the clinical evidence for TCAM in EjD remains unclear. Therefore, this study aims to systematically review human clinical trials investigating the use of TCAM to treat EjD. Materials and Methods: A systematic review of the literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted by searching Scopus and PubMed databases. Controlled clinical trials investigating a cohort of male patients diagnosed primarily with EjD and undergoing any TCAM intervention compared to any comparison group were included. Quality of the studies was assessed using the Cochrane Risk of Bias tool for randomized controlled trials. Results: Following article screening, 22 articles were included. Of these, 21 investigated TCAM in premature ejaculation, and only 1 investigated TCAM in retrograde ejaculation. Different TCAM categories included studies that investigated lifestyle, exercise and/or physical activities (n = 7); herbal medicine supplements (n = 5); topical herbal applications (n = 4); acupuncture or electroacupuncture (n = 3); vitamin, mineral and/or nutraceutical supplements (n = 1); hyaluronic acid penile injection (n = 1); and music therapy (n = 1). Only 31.8% (n = 7) of the included studies were found to have a low risk of bias. The available studies were widely heterogenous in the TCAM intervention investigated and comparison groups used. However, the included studies generally showed improved outcomes intra-group and when compared to placebo. Conclusions: Different TCAM interventions may have an important role particularly in the management of PE. However, more studies using standardized interventions are needed.


  • Understandings and practices: Towards socially responsive curricula for the health professions

    by Anthea Hansen, Penelope Engel-Hills, Cecilia Jacobs, Julia Blitz, Richard Cooke, Lucia Hess-April, Kristian Leisegang, Niri Naidoo, Mariette Volschenk, Susan van Schalkwyk

    Global health inequities have created an urgency for health professions education to transition towards responsive and contextually relevant curricula. Such transformation and renewal processes hold significant implications for those educators responsible for implementing the curriculum. Currently little is known about how health professions educators across disciplines understand a responsive curriculum and how this understanding might influence their practice. We looked at curricula that aim to deliver future health care professionals who are not only clinically competent but also critically conscious of the contexts in which they serve and the health care systems within which they practice. We conducted a qualitative study across six institutions in South Africa, using focus group discussions and in-depth individual interviews to explore (i) how do health professions educators understand the principles that underpin their health professions education curriculum; and (ii) how do these understandings of health professions educators shape their teaching practices? The transcripts were analysed thematically following multiple iterations of critical engagement to identify patterns of meaning across the entire dataset. The results reflected a range of understandings related to knowing, doing, and being and becoming; and a range of teaching practices that are explicit, intentionally designed, take learning to the community, embrace a holistic approach, encourage safe dialogic encounters, and foster reflective practice through a complex manner of interacting. This study contributes to the literature on health professions education as a force for social justice. It highlights the implications of transformative curriculum renewal and offers insights on how health professions educators embrace notions of social responsiveness and health equity to engage with these underlying principles within their teaching.


  • Open Access

    The Impact of COVID‐19 Vaccines on Male Semen Parameters: A Retrospective Cohort Study

    by Kristian Leisegang, Renata Finelli, Lionel Moungala, Faith Moichela, Keenau Pearce, Ranjith Ramasamy, Ralf Henkel

    The emergence of SARS‐CoV‐2 and the subsequent COVID‐19 pandemic necessitated the development of adequate vaccines. Despite vaccines being demonstrated to be safe and effective for preventing severe disease and death, vaccine hesitancy remains. Reasons include concerns over adverse effects on male fertility, which have not been widely investigated. Therefore, this study is aimed at determining the impact of COVID‐19 vaccination on semen parameters in a retrospective cohort study of South African males undergoing fertility assessment. The patients for this study were adult men who have previously undergone routine semen analysis for fertility assessment at Androcryos Andrology Laboratory (Johannesburg, South Africa) between March 2021 and March 2022. They also received vaccination within 3 months following a semen analysis and underwent a second semen analysis any time post‐COVID‐19 vaccination. From 277 records analysed, 46 patients met the inclusion criteria, receiving the Pfizer‐BioNTech (BNT162b1) (63%), Johnson and Johnson (JNJ‐78436735/Ad26.COV2S) (34.8%), and the AstraZeneca (AZD1222) (2.2%) vaccines. Sperm concentration significantly increased postvaccination (P = 0.0001), with no significant changes in semen pH, volume, total sperm count, progressive motility, normal sperm morphology, or chromatin condensation. Results were not influenced by age, type of vaccine received, and the number of days following vaccination, as depicted by multiple regression analysis. In conclusion, there is no evidence of a negative impact of COVID‐19 vaccination on male semen parameters, which is consistent with the emerging literature on COVID‐19 vaccination and male fertility. COVID‐19 vaccinations should not be dismissed based on fear of adverse effects on male fertility parameters.


  • Open Access

    Impact of Varicocele Repair on Semen Parameters in Infertile Men: A Systematic Review and Meta-Analysis

    by Ashok Agarwal, Rossella Cannarella, Ramadan Saleh, Florence Boitrelle, Murat Gül, Tuncay Toprak, Gianmaria Salvio, Mohamed Arafa, Giorgio I. Russo, Ahmed M. Harraz, et al.

    Agarwal A, et al. World J Mens Health. 2022 Oct;40:e70. https://doi.org/10.5534/wjmh.220142


  • Open Access

    Eurycoma longifolia (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials

    by Kristian Leisegang, Renata Finelli, Suresh C. Sikka, Manesh Kumar Panner Selvam

    Background and Objectives: Male hypogonadism is a clinical disorder characterized by reduced serum testosterone in men. Although treatment using herbal medicines, including Eurycoma longifolia, has been investigated, the benefits remain unclear. This study aims to investigate the efficacy of E. longifolia as a sole intervention to increase testosterone levels in males. Materials and Methods: We conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) according to the PRISMA guidelines. Relevant articles were retrieved from the databases PubMed, Scopus, Web of Science, Cochrane, Ovid/Embase, and Google Scholar. Results: After literature screening, a total of nine studies was included in the systematic review. Five RCTs were included in the meta-analysis. A significant improvement in total testosterone levels after E. longifolia treatment was mostly reported in both healthy volunteers and hypogonadal men. The random model effect revealed a significant increase (SMD = 1.352, 95% CI 0.565 to 2.138, p = 0.001) in the total testosterone levels in men receiving E. longifolia supplementation, which was confirmed in the hypogonadism subgroup. Conclusions: This systematic review and meta-analysis of the literature supports the possible use of E. longifolia supplementation for enhancing testosterone production. Although more research is required before its use in clinical practice, this may represent a safe and promising therapeutic option, particularly in hypogonadal men.


  • Oxidative Stress in Men with Obesity, Metabolic Syndrome and Type 2 Diabetes Mellitus: Mechanisms and Management of Reproductive Dysfunction

    by Kristian Leisegang

    Reactive oxygen species (ROS) are critical physiological mediators of cellular function, including male fertility. When ROS exceed antioxidant regulation, oxidative stress occurs which is detrimental to cellular function. Oxidative stress has been found to be a central mediator of obesity, metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM), as well as with male infertility. Human studies have correlated testicular oxidative stress in obese males, and animal studies have further provided insight into potential mechanisms of action. Management of oxidative stress is not well defined. Appropriate nutrition and exercise can be recommended for all diabetic patients, and weight loss for obese patients with MetS and T2DM. Consideration of dietary supplements including micronutrients, antioxidants or medicinal herbs are recommended. Metformin may also offer benefits on testicular oxidative stress and fertility parameters. Significantly more research on causation, mechanisms, clinical assessments and appropriate management of infertility on obesity, MetS and T2DM is still required. Keywords Obesity Metabolic syndrome Type 2 diabetes mellitus Oxidative stress Inflammation Male infertility Semen parameters Spermatogenesis