Lars Björndahl - Academia.edu (original) (raw)
Papers by Lars Björndahl
Human Reproduction, Jun 1, 2023
subtypes of EVs include exosomes, microvesicles, and apoptotic bodies. They can be discriminated ... more subtypes of EVs include exosomes, microvesicles, and apoptotic bodies. They can be discriminated according to their size, cargo, biogenesis, release pathways, and functions. These organelles serve as vehicles for transferring bioactive molecules as lipids, proteins, cytokines, and regulatory molecules as RNAs, locally and remotely. A wide range of cell types releases EVs, and their cargo differs under normal and pathological conditions. These facts make them possible biomarkers for diagnosing and treating different medical conditions. Isolation of EVs from various female and male reproductive tissues such as prostate, epididymis, seminal fluid, fallopian tube, cumulus, and mural granulosa cells, oocytes, embryos at various developmental stages, endometrium, and decidua has been described. Oogenesis, sperm maturation, fertilization, embryo development, and implantation are composite processes highly reliant on the interaction between tissues and cells. Existing data show that miRNAs and proteins in epididymal fluid associated with testicular maturation are transferred to the sperm by EVs Ovarian follicular growth is a synchronized process comprising bidirectional communication between the oocyte, cumulus, and mural granulosa cells. Some studies have identified EVs from several species' follicular fluid (FF), including bovine, equine, and human. To date, data linking EVs with oogenesis are primarily descriptive. EV micro-RNA (EV-miRNA) isolated from FF target pathways as mitogen-activated protein kinase (MAPK), wingless signaling pathway (WNT), epidermal growth factor receptor (ErbB), and transforming growth factor beta (TGFß). These pathways are related to folliculogenesis, meiotic resumption, and ovulation. EV-miRNAs isolated from follicles that contained mature oocytes were associated with fertilization potential and embryo quality. In addition, EVs derived from microvillous-rich oolemma may neutralize acrosome reaction and prevent polyspermy. Animal and human studies have confirmed that embryos at various developmental stages secrete EVs into the extracellular medium, and embryos internalize EVs. The number, miRNA profile, and size of EVs secreted vary across the cycle and according to embryos' developmental potential. Endometrial EVs release miRNAs essential for the blastocyst's adhesion. In ovine, EVs were identified from the uterine lumen and uterine flushing during implantation. Uterine lumen flush EVs were internalized by the trophectoderm cells in the conceptus, reducing trophectoderm cell proliferation. The study of EVs in reproduction has increased exponentially in the last few years. Evidence support that these organelles contribute to oogenesis, Abstract citation ID: dead093.343 O-283 Impact of metabolic syndrome and effect of treatment on male and female reproductive capacity R. Legro 1
CRC Press eBooks, Jun 3, 2010
International Journal of Andrology, Aug 16, 2016
Human Reproduction, Oct 9, 2012
Is there a need for a specific guide addressing studies of seminal quality? summary answer: The p... more Is there a need for a specific guide addressing studies of seminal quality? summary answer: The proposed guidelines for the appraisal of SEMinal QUAlity studies (SEMQUA) reflect the need for improvement in methodology and research on semen quality. what is known already: From an examination of other instruments used to assess the quality of diagnostic studies, there was no guideline on studies of seminal quality. study design, size and duration: Through systematic bibliographic search, potential items were identified and grouped into four blocks: participants, analytical methods, statistical methods and results. participants/materials, setting and methods: Our findings were presented to a panel of experts who were asked to identify opportunities for improvement. Then, a checklist was designed containing the questions generated by the items that summarize the essential points that need to be considered for the successful outcome of a SEMQUA. main results and the role of chance: Eighteen items were identified, from which 19 questions, grouped into four blocks, were generated to constitute the final checklist. An explanation for the inclusion of each item was provided and some examples found in the bibliographic search were cited. limitations and reasons for caution: We consider that not all items are equally applicable to all study designs, and so the hypothetical results are not comparable. For that reason, a score would not be fair to critically appraise a study. This checklist is presented as an instrument for appraising SEMQUAs and therefore remains open to constructive criticism. It will be further developed in the future, in parallel with the continuing evolution of SEMQUAs. wider implications of the findings: The final configuration of the SEMQUA is in the form of a checklist, and includes the items generally considered to be essential for the proper development of a SEMQUA. The final checklist produced has various areas of application; for example, it would be useful for designing and constructing a SEMQUA, for reviewing a paper on the question, for educational purposes or as an instrument for appraising the quality of research articles in this field.
Human Reproduction, Jul 1, 2021
How does convolutional neural network (CNN)-predicted sperm motility correlate with manual assess... more How does convolutional neural network (CNN)-predicted sperm motility correlate with manual assessment according to the WHO guidelines. CNN predicts sperm motility comparable to reference laboratories in the ESHRE-SIGA External Quality Assessment Programme for Semen Analysis. Manual sperm motility assessment according to WHO guidelines is regarded as the gold standard. To obtain reliable and reproducible results, comprehensive training is essential as well as running internal and external quality control. Prediction based on artificial intelligence can potentially transfer human-level performance into models that perform the task faster and can avoid human assessor variations. CNNs have been groundbreaking in image processing. To develop AI models with high predictive power, the data set used should be of high quality and sperm motility assessment based on WHO guidelines. Videos of 65 fresh semen samples obtained from the ESHRE-SIGA External Quality Assessment Programme for Semen Analysis (from the period 2006–2018) were used in the development of the model. One video was captured for each semen sample. Sperm motility data was obtained from manual assessment of the videos according to WHO criteria by reference laboratories in the programme. Rapid progressive motility was also included. Ten-fold cross-validation was used to compensate for the relatively small dataset. The mean values of the reference laboratories were used. Sparse optical flow of the sperm videos was generated from each second of each video and fed into a ResNet50 convolutional neural network. For training, Adam was used to optimize the weights and mean squared error (MSE) to measure loss. For baseline, ZeroR (pseudo regression) was performed. Results are reported as MAE. For correlation analysis, Pearson’s r was used. Predicting sperm motility based on the optical flow generated from the videos, achieved an average MAE of 0.05 across progressive (0.06), non-progressive (0.04) and immotile sperm (0.05). The ZeroR baseline was 0.09, indicating that the method is able to capture the movement of the spermatozoa and predict motility with low error. Pearson’s correlation between manually and AI-predicted motility showed r of 0.88, p < 0.001 for progressive, 0.59, p < 0.001 for non-progressive and 0.89, p < 0.001 for immotile sperm. When predicting rapid progressive motility, the average MAE was 0.07 across rapid progressive (0.11), slow progressive (0.09), non-progressive (0.04) and immotile sperm (0.05). Pearson’s correlation analysis between manually and AI-predicted motility showed r of 0.67, p < 0.001 for rapid progressive, 0.41, p < 0.001 for slow progressive, 0.51, p < 0.001 for non-progressive and 0.88, p < 0.001 for immotile sperm. The results show that differentiating between rapid progressive and slow progressive motility is difficult, but the model is still able to do this better than the ZeroR baseline, which was 0.15 for rapid progressive and 0.11 for slow progressive. This is interesting since rapid progressive motility has been regarded challenging to assess. The next step would be to compare the results of the algorithm to the human performance. The sample size is small. The model is based on videos of high quality, and the performance may not transfer well to videos of lower quality. The performance for rapid progressive motility, which may have an important clinical value, has to be improved. Wider implications of the findings: This CNN model has a potential to assess sperm motility according to WHO guidelines for progressive motility and immotility. The error values for the automatic predictions are low, and the model shows a good performance taking into account that only videos were used to perform the prediction. Not applicable
Biochemical Pharmacology, Dec 1, 2020
Recent studies have linked prolonged use of the most commonly prescribed proton pump inhibitors (... more Recent studies have linked prolonged use of the most commonly prescribed proton pump inhibitors (PPIs) with declined human sperm function and infertility. Here, we report for the first time the most plausible underlying mechanism for this unwarranted secondary mode of action. We followed up on a recent serendipitous discovery in our laboratory regarding PPIs' off-target action and performed detailed pharmacodynamic analyses by combining in silico and in vitro studies to determine the off-target effect of one of the most commonly used PPI, esomeprazole, on the key human acetylcholine biosynthesizing enzyme, choline acetyltransferase (ChAT; EC 2.3.1.6). A pivotal enzyme in the spermic cholinergic system that governs the sperm motility, concentration and quality. Our results were conclusive and showed that both the racemic form, omeprazole and its pure S-enantiomer, esomeprazole, acted as potent mixed-competitive inhibitor of human ChAT with a global inhibition constant (K i) of 88 nM (95%CI: 10-167 nM) for esomeprazole and 178 nM (95%CI: 140-230 nM) for the racemic drug omeprazole. Most importantly, esomeprazole substantially reduces both total number of motile sperm (by 36%, p < 0.001; and 21% p < 0.0001, at 10 and 100 nM, respectively) as well as the total number of sperm with progressive motility (by 42% p < 0.0016 and by 26% p < 0.0001, respectively) after 60 min relative to 20 min incubation in our ex vivo functional assay performed on ejaculated human sperm. In conclusion, this study presents a completely new perspective regarding PPIs secondary mode of action/unwarranted side effects and calls for further mechanistic and larger clinical studies to elucidate the role of PPIs in infertility.
International Journal of Andrology, Aug 1, 1990
Zinc-binding properties were studied in 'prostatic fluid', i.e. in seminal plasma from patients w... more Zinc-binding properties were studied in 'prostatic fluid', i.e. in seminal plasma from patients with agenesis of the Wolffian ducts, and in split-ejaculate fractions dominated by seminal vesicular fluid. The effect of seminal fluid, with different zinc-binding properties, on the stability of zinc-dependent sperm chromatin was assessed by exposing sperm to 1% sodium dodecyl sulphate (SDS) for 60 min. Citrate was the only zinc ligand in 'prostatic fluid', as revealed by gel chromatography. Zinc in this fluid enhanced the stability of sperm chromatin. In contrast, the stability of sperm chromatin was decreased in seminal plasma dominated by vesicular fluid. These results are in accordance with the concept that prostatic fluid ensures the appropriate zinc content and stability of sperm chromatin, whereas abundance of vesicular fluid may jeopardize chromatin stability by reducing chromatin zinc content.
Cambridge University Press eBooks, Jun 1, 2010
Science Translational Medicine, Nov 30, 2022
Close to half of the world's pregnancies are still unplanned, reflecting a clear unmet need in co... more Close to half of the world's pregnancies are still unplanned, reflecting a clear unmet need in contraception. Ideally, a contraceptive would provide the high efficacy of hormonal treatments, without the systemic side effects of hormones. Here we propose topical reinforcement of the cervical mucus by chitosan mucoadhesive polymers as a form of female contraceptive. Chitosans larger than 7 kDa effectively crosslinked human ovulatory cervical mucus to prevent sperm penetration in vitro. We then demonstrated in vivo using the ewe as a model that vaginal gels containing chitosan could stop ram sperm at the entrance of the cervical canal and prevent them from reaching the uterus, whereas the same gels without chitosan did not significantly limit sperm migration. The chitosan did not affect sperm motility in vitro or in vivo, suggesting reinforcement of the mucus physical barrier as the primary mechanism of action. The chitosan formulations did not damage or irritate the ewe vaginal epithelium, in contrast to nonoxynol-9 spermicide. The demonstration that cervical mucus can be reinforced topically to create an effective barrier to sperm may therefore form the technological basis for muco-cervical barrier contraceptives with the potential to become an alternative to hormonal contraceptives.
ACS Applied Materials & Interfaces, Nov 14, 2019
The many interesting properties of chitosan polysaccharides have prompted their extensive use as ... more The many interesting properties of chitosan polysaccharides have prompted their extensive use as biomaterial building blocks, for instance as antimicrobial coatings, tissue engineering scaffolds, and drug delivery vehicles. The translation of these chitosan-based systems to the clinic still requires a deeper understanding of their safety profiles. For instance, the widespread claim that chitosans are spermicidal is supported by little to no data. Herein, we thoroughly investigate whether chitosan oligomer (CO) molecules can impact the functional and structural features of human spermatozoa. By using a large number of primary sperm cell samples and by isolating the effect of chitosan from the effect of sperm dissolution buffer, we provide the first realistic and complete picture of the effect of chitosans on sperms. We found that CO binds to cell surfaces or/and is internalized by cells and affected the average path velocity of the spermatozoa, in a dose-dependent manner. However, CO did not affect the progressive motility, motility, or sperm morphology, nor did it cause loss of plasma membrane integrity, reactive oxygen species production, or DNA damage. A decrease in spermatozoa adenosine triphosphate levels, which was especially significant at higher CO concentrations, points to possible interference of CO with mitochondrial functions or the glycolysis processes. With this first complete and in-depth look at the spermicidal activities of chitosans, we complement the complex picture of the safety profile of chitosans and inform on further use of chitosans in biomedical applications.
Zenodo (CERN European Organization for Nuclear Research), Nov 30, 2022
Close to half of the world's pregnancies are still unplanned, reflecting a clear unmet need in co... more Close to half of the world's pregnancies are still unplanned, reflecting a clear unmet need in contraception. Ideally, a contraceptive would provide the high efficacy of hormonal treatments, without the systemic side effects of hormones. Here we propose topical reinforcement of the cervical mucus by chitosan mucoadhesive polymers as a form of female contraceptive. Chitosans larger than 7 kDa effectively crosslinked human ovulatory cervical mucus to prevent sperm penetration in vitro. We then demonstrated in vivo using the ewe as a model that vaginal gels containing chitosan could stop ram sperm at the entrance of the cervical canal and prevent them from reaching the uterus, whereas the same gels without chitosan did not significantly limit sperm migration. The chitosan did not affect sperm motility in vitro or in vivo, suggesting reinforcement of the mucus physical barrier as the primary mechanism of action. The chitosan formulations did not damage or irritate the ewe vaginal epithelium, in contrast to nonoxynol-9 spermicide. The demonstration that cervical mucus can be reinforced topically to create an effective barrier to sperm may therefore form the technological basis for muco-cervical barrier contraceptives with the potential to become an alternative to hormonal contraceptives.
Semen analysis is central in infertility investigation. Manual assessment of sperm motility accor... more Semen analysis is central in infertility investigation. Manual assessment of sperm motility according to the WHO recommendations is the golden standard, and extensive training is a requirement for accurate and reproducible results. Deep convolutional neural networks (DCNN) are especially suitable for image classification. In this study, we evaluated the performance of DCNN models in predicting the proportion of sperm in the WHO motility categories. The models were evaluated using 10-fold cross-validation with 65 video recordings of wet semen preparations from individual men and corresponding manually assessed data obtained from an external quality assessment programme for semen analysis. The convolutional neural network used was ResNet-50. One model was trained to predict the three categories progressive motility, non-progressive motility, and immotile spermatozoa. Another model was used in predicting four categories, where progressive motility was differentiated into rapid and slow...
Human Reproduction, 2021
Study question How can an automation & artificial intelligent tools be developed to perform accor... more Study question How can an automation & artificial intelligent tools be developed to perform according to WHO recommendations? Summary answer Developing CASA performs at < 20% error margin requires AI trained with high quality datasets and a robotic system adheres to WHO guidelines. What is known already A survey of 40 andrology laboratories, in 22 countries, revealed that > 90% had nonconformities in correct use of equipment, standardisation of protocols and quality control, leading to a lack of compliance to WHO protocols. Conventional CASA systems can standardize analysis, but controversy has occurred due to differences between manual and automated analyses stemming from: 1) all cells in a semen sample are detected including debris; 2) protocol variation when compared to top-notch manual analysis. The first point can be addressed by AI. The second point can be addressed by robotics designed to adhere to WHO guidelines. Study design, size, duration A mojo AISA (AI-powered sem...
Human Reproduction, 2021
Study question Can a CASA system based on Artificial Intelligence perform as well as manual semen... more Study question Can a CASA system based on Artificial Intelligence perform as well as manual semen assessment, within the WHO error margins? Summary answer The AI-based CASA systems that mimic high quality assessments show great potential for reducing clinical workloads while increasing treatment efficacy. What is known already The field of male-factor fertility investigation is still lacking an automated semen analysis system that can be widely clinically adopted. By leveraging state-of-the-art robotics and Artificial Intelligence (AI), it was possible to build mojo AISA which is an AI and robotic platform designed according to WHO recommendation for semen analysis. This system is based on AI software with a unique convolutional neural network (CNN) that detects and measures sperm concentration and motility while ruling out unwanted cells and debris in raw samples. Study design, size, duration This study presents and validates the mojo AISA device. A total of 60 patient samples at A...
Human Reproduction, 2011
background: External quality assessment is essential in modern andrology laboratories. To assess ... more background: External quality assessment is essential in modern andrology laboratories. To assess the proficiency of laboratories participating in an external quality assessment programme (EQAP), limits for acceptable variability must be determined. Limits currently specified largely depend on criteria set by the organizers of individual EQAP schemes. The objective of this study was to evaluate the different criteria described in ISO 13528:2005 for calculating acceptable variability in EQAP when applied to basic semen analysis parameters. methods and results: The data used in this study were the means and standard deviations obtained for independent samples from two EQAPs, one national (Spanish) and one international (European). The acceptable variability according to ISO 13528:2005 was calculated using four types of criteria: (i) +3 standard deviations of the results of all participating laboratories; (ii) +3 standard deviations of the results of expert laboratories; (iii) quality specifications based on biological variability, state-of-the-art and clinicians' opinions and (iv) the same quality specifications adjusted for the uncertainty of the assigned value. The first two strategies resulted in very wide ranges of acceptable variability. Conversely, the strategy based only on quality specifications resulted in very narrow ranges. For the fourth strategy, acceptable ranges were intermediate between the results produced with the other strategies. The third and fourth strategies did not produce observable differences in acceptable ranges when the model used for calculating the specifications of analytical quality was changed. conclusions: It is essential that EQAPs for semen parameters should determine the ranges for acceptable variability in results. Moreover, these ranges must be clinically useful, i.e. the variability should have a minimal negative impact on clinical decisions. The exact definition of 'expert laboratory' is more important than the model chosen for estimating analytical quality specifications in an EQAP for semen parameters in basic semen analysis.
Human Reproduction
Biomedical science is rapidly developing in terms of more transparency, openness and reproducibil... more Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.
Reproductive BioMedicine Online, 2015
Pim Janssens is a senior clinical chemist. He studied biochemistry in Amsterdam, obtained a PhD i... more Pim Janssens is a senior clinical chemist. He studied biochemistry in Amsterdam, obtained a PhD in science, and went on to train as a clinical chemist. He is specialized in inborn errors of metabolism. He was laboratory director of the Department of Clinical Chemistry and Haematology & Semen Bank at Rijnstate Hospital for 6 years, with an interest in exploring the professional, organizational and ethical aspects of gamete donation. Pim Janssens has been the chairman of the Dutch Society of Semen Banks for more than 10 years, and has published articles on gamete donation, laboratory organization, test ordering management and risk assessment and management.
Scandinavian Journal of Urology and Nephrology, 1988
The stability and the content of zinc of the chromatin were studied in spermatozoa from ten men w... more The stability and the content of zinc of the chromatin were studied in spermatozoa from ten men with unexplained infertility, and in spermatozoa from five fertile donors. A positive relation was found between zinc in sperm nuclei (X-ray microanalysis) and the resistance of the chromatin to decondense in sodium dodecylsulfate (SDS). The infertile men had lower degree of sperm chromatin stability and lower sperm zinc content than the fertile donors. A subgroup of the infertile men, which all had minor clinical signs of prostatic inflammatory reaction, had the lowest content of zinc in the chromatin and the lowest degree of chromatin stability. A low content of nuclear zinc would impair the structural stability of the chromatin and thereby increase the vulnerability of the male genome. This mechanism may be one explanation for the reduced fertility of the men with minor inflammation of the prostate.
Human Reproduction, 2011
Introduction: Urogenital infections have been known to play an important role in male fertility d... more Introduction: Urogenital infections have been known to play an important role in male fertility disorders. Data concerning the contribution of herpes simplex virus (HSV) in etiology of male infertility are controversial. The aim of present study was to evaluate HSV influence on male germ cells in sperm samples and in the testis organotypic culture. Material and Methods: 93 sperm samples from men attending infertility clinic and 49 samples from sperm donors were studied by rapid culture method (RCM) and by polymerase chain reaction in situ (PCR-in situ) to detect HSV. To evaluate HSV influence on major sperm parameters semen analysis was performed. In order to reveal HSV impact on immature germ cells human testis organotypic culture was obtained, infected and studied during 14 days. Results: Infectious HSV was found in 20,4% of samples from infertile men and in 6,1% of probes from healthy donors (p < 0.05). HSV DNA was detected in 26,9% and 2% of samples, respectively (p < 0.05). Percentage of motile spermatozoa and of gametes with normal morphology was lower in HSV-infected samples comparing with uninfected ones: 21% vs 40% (p < 0.05) and 13% vs 19% (p < 0.05), respectively. Concentration of gametes didn't differ among these groups. Morphological studies of HSV-infected and uninfected human organotypic culture revealed significant decrease in population of spermatogonia, spermatocytes and spermatides, but not in spermatozoa. Conclusions: The data obtained suppose that HSV is more frequently detected in sperm of infertile men than in healthy ones. Decrease in immature germ cells population and decline in number of mature gametes with normal motility and morphology-are possible mechanism of HSV-associated fertility disorders. P-003 Comet assay profile of single and double-strand sperm DNA damage in different patient groups
Human Reproduction, Jun 1, 2023
subtypes of EVs include exosomes, microvesicles, and apoptotic bodies. They can be discriminated ... more subtypes of EVs include exosomes, microvesicles, and apoptotic bodies. They can be discriminated according to their size, cargo, biogenesis, release pathways, and functions. These organelles serve as vehicles for transferring bioactive molecules as lipids, proteins, cytokines, and regulatory molecules as RNAs, locally and remotely. A wide range of cell types releases EVs, and their cargo differs under normal and pathological conditions. These facts make them possible biomarkers for diagnosing and treating different medical conditions. Isolation of EVs from various female and male reproductive tissues such as prostate, epididymis, seminal fluid, fallopian tube, cumulus, and mural granulosa cells, oocytes, embryos at various developmental stages, endometrium, and decidua has been described. Oogenesis, sperm maturation, fertilization, embryo development, and implantation are composite processes highly reliant on the interaction between tissues and cells. Existing data show that miRNAs and proteins in epididymal fluid associated with testicular maturation are transferred to the sperm by EVs Ovarian follicular growth is a synchronized process comprising bidirectional communication between the oocyte, cumulus, and mural granulosa cells. Some studies have identified EVs from several species' follicular fluid (FF), including bovine, equine, and human. To date, data linking EVs with oogenesis are primarily descriptive. EV micro-RNA (EV-miRNA) isolated from FF target pathways as mitogen-activated protein kinase (MAPK), wingless signaling pathway (WNT), epidermal growth factor receptor (ErbB), and transforming growth factor beta (TGFß). These pathways are related to folliculogenesis, meiotic resumption, and ovulation. EV-miRNAs isolated from follicles that contained mature oocytes were associated with fertilization potential and embryo quality. In addition, EVs derived from microvillous-rich oolemma may neutralize acrosome reaction and prevent polyspermy. Animal and human studies have confirmed that embryos at various developmental stages secrete EVs into the extracellular medium, and embryos internalize EVs. The number, miRNA profile, and size of EVs secreted vary across the cycle and according to embryos' developmental potential. Endometrial EVs release miRNAs essential for the blastocyst's adhesion. In ovine, EVs were identified from the uterine lumen and uterine flushing during implantation. Uterine lumen flush EVs were internalized by the trophectoderm cells in the conceptus, reducing trophectoderm cell proliferation. The study of EVs in reproduction has increased exponentially in the last few years. Evidence support that these organelles contribute to oogenesis, Abstract citation ID: dead093.343 O-283 Impact of metabolic syndrome and effect of treatment on male and female reproductive capacity R. Legro 1
CRC Press eBooks, Jun 3, 2010
International Journal of Andrology, Aug 16, 2016
Human Reproduction, Oct 9, 2012
Is there a need for a specific guide addressing studies of seminal quality? summary answer: The p... more Is there a need for a specific guide addressing studies of seminal quality? summary answer: The proposed guidelines for the appraisal of SEMinal QUAlity studies (SEMQUA) reflect the need for improvement in methodology and research on semen quality. what is known already: From an examination of other instruments used to assess the quality of diagnostic studies, there was no guideline on studies of seminal quality. study design, size and duration: Through systematic bibliographic search, potential items were identified and grouped into four blocks: participants, analytical methods, statistical methods and results. participants/materials, setting and methods: Our findings were presented to a panel of experts who were asked to identify opportunities for improvement. Then, a checklist was designed containing the questions generated by the items that summarize the essential points that need to be considered for the successful outcome of a SEMQUA. main results and the role of chance: Eighteen items were identified, from which 19 questions, grouped into four blocks, were generated to constitute the final checklist. An explanation for the inclusion of each item was provided and some examples found in the bibliographic search were cited. limitations and reasons for caution: We consider that not all items are equally applicable to all study designs, and so the hypothetical results are not comparable. For that reason, a score would not be fair to critically appraise a study. This checklist is presented as an instrument for appraising SEMQUAs and therefore remains open to constructive criticism. It will be further developed in the future, in parallel with the continuing evolution of SEMQUAs. wider implications of the findings: The final configuration of the SEMQUA is in the form of a checklist, and includes the items generally considered to be essential for the proper development of a SEMQUA. The final checklist produced has various areas of application; for example, it would be useful for designing and constructing a SEMQUA, for reviewing a paper on the question, for educational purposes or as an instrument for appraising the quality of research articles in this field.
Human Reproduction, Jul 1, 2021
How does convolutional neural network (CNN)-predicted sperm motility correlate with manual assess... more How does convolutional neural network (CNN)-predicted sperm motility correlate with manual assessment according to the WHO guidelines. CNN predicts sperm motility comparable to reference laboratories in the ESHRE-SIGA External Quality Assessment Programme for Semen Analysis. Manual sperm motility assessment according to WHO guidelines is regarded as the gold standard. To obtain reliable and reproducible results, comprehensive training is essential as well as running internal and external quality control. Prediction based on artificial intelligence can potentially transfer human-level performance into models that perform the task faster and can avoid human assessor variations. CNNs have been groundbreaking in image processing. To develop AI models with high predictive power, the data set used should be of high quality and sperm motility assessment based on WHO guidelines. Videos of 65 fresh semen samples obtained from the ESHRE-SIGA External Quality Assessment Programme for Semen Analysis (from the period 2006–2018) were used in the development of the model. One video was captured for each semen sample. Sperm motility data was obtained from manual assessment of the videos according to WHO criteria by reference laboratories in the programme. Rapid progressive motility was also included. Ten-fold cross-validation was used to compensate for the relatively small dataset. The mean values of the reference laboratories were used. Sparse optical flow of the sperm videos was generated from each second of each video and fed into a ResNet50 convolutional neural network. For training, Adam was used to optimize the weights and mean squared error (MSE) to measure loss. For baseline, ZeroR (pseudo regression) was performed. Results are reported as MAE. For correlation analysis, Pearson’s r was used. Predicting sperm motility based on the optical flow generated from the videos, achieved an average MAE of 0.05 across progressive (0.06), non-progressive (0.04) and immotile sperm (0.05). The ZeroR baseline was 0.09, indicating that the method is able to capture the movement of the spermatozoa and predict motility with low error. Pearson’s correlation between manually and AI-predicted motility showed r of 0.88, p < 0.001 for progressive, 0.59, p < 0.001 for non-progressive and 0.89, p < 0.001 for immotile sperm. When predicting rapid progressive motility, the average MAE was 0.07 across rapid progressive (0.11), slow progressive (0.09), non-progressive (0.04) and immotile sperm (0.05). Pearson’s correlation analysis between manually and AI-predicted motility showed r of 0.67, p < 0.001 for rapid progressive, 0.41, p < 0.001 for slow progressive, 0.51, p < 0.001 for non-progressive and 0.88, p < 0.001 for immotile sperm. The results show that differentiating between rapid progressive and slow progressive motility is difficult, but the model is still able to do this better than the ZeroR baseline, which was 0.15 for rapid progressive and 0.11 for slow progressive. This is interesting since rapid progressive motility has been regarded challenging to assess. The next step would be to compare the results of the algorithm to the human performance. The sample size is small. The model is based on videos of high quality, and the performance may not transfer well to videos of lower quality. The performance for rapid progressive motility, which may have an important clinical value, has to be improved. Wider implications of the findings: This CNN model has a potential to assess sperm motility according to WHO guidelines for progressive motility and immotility. The error values for the automatic predictions are low, and the model shows a good performance taking into account that only videos were used to perform the prediction. Not applicable
Biochemical Pharmacology, Dec 1, 2020
Recent studies have linked prolonged use of the most commonly prescribed proton pump inhibitors (... more Recent studies have linked prolonged use of the most commonly prescribed proton pump inhibitors (PPIs) with declined human sperm function and infertility. Here, we report for the first time the most plausible underlying mechanism for this unwarranted secondary mode of action. We followed up on a recent serendipitous discovery in our laboratory regarding PPIs' off-target action and performed detailed pharmacodynamic analyses by combining in silico and in vitro studies to determine the off-target effect of one of the most commonly used PPI, esomeprazole, on the key human acetylcholine biosynthesizing enzyme, choline acetyltransferase (ChAT; EC 2.3.1.6). A pivotal enzyme in the spermic cholinergic system that governs the sperm motility, concentration and quality. Our results were conclusive and showed that both the racemic form, omeprazole and its pure S-enantiomer, esomeprazole, acted as potent mixed-competitive inhibitor of human ChAT with a global inhibition constant (K i) of 88 nM (95%CI: 10-167 nM) for esomeprazole and 178 nM (95%CI: 140-230 nM) for the racemic drug omeprazole. Most importantly, esomeprazole substantially reduces both total number of motile sperm (by 36%, p < 0.001; and 21% p < 0.0001, at 10 and 100 nM, respectively) as well as the total number of sperm with progressive motility (by 42% p < 0.0016 and by 26% p < 0.0001, respectively) after 60 min relative to 20 min incubation in our ex vivo functional assay performed on ejaculated human sperm. In conclusion, this study presents a completely new perspective regarding PPIs secondary mode of action/unwarranted side effects and calls for further mechanistic and larger clinical studies to elucidate the role of PPIs in infertility.
International Journal of Andrology, Aug 1, 1990
Zinc-binding properties were studied in 'prostatic fluid', i.e. in seminal plasma from patients w... more Zinc-binding properties were studied in 'prostatic fluid', i.e. in seminal plasma from patients with agenesis of the Wolffian ducts, and in split-ejaculate fractions dominated by seminal vesicular fluid. The effect of seminal fluid, with different zinc-binding properties, on the stability of zinc-dependent sperm chromatin was assessed by exposing sperm to 1% sodium dodecyl sulphate (SDS) for 60 min. Citrate was the only zinc ligand in 'prostatic fluid', as revealed by gel chromatography. Zinc in this fluid enhanced the stability of sperm chromatin. In contrast, the stability of sperm chromatin was decreased in seminal plasma dominated by vesicular fluid. These results are in accordance with the concept that prostatic fluid ensures the appropriate zinc content and stability of sperm chromatin, whereas abundance of vesicular fluid may jeopardize chromatin stability by reducing chromatin zinc content.
Cambridge University Press eBooks, Jun 1, 2010
Science Translational Medicine, Nov 30, 2022
Close to half of the world's pregnancies are still unplanned, reflecting a clear unmet need in co... more Close to half of the world's pregnancies are still unplanned, reflecting a clear unmet need in contraception. Ideally, a contraceptive would provide the high efficacy of hormonal treatments, without the systemic side effects of hormones. Here we propose topical reinforcement of the cervical mucus by chitosan mucoadhesive polymers as a form of female contraceptive. Chitosans larger than 7 kDa effectively crosslinked human ovulatory cervical mucus to prevent sperm penetration in vitro. We then demonstrated in vivo using the ewe as a model that vaginal gels containing chitosan could stop ram sperm at the entrance of the cervical canal and prevent them from reaching the uterus, whereas the same gels without chitosan did not significantly limit sperm migration. The chitosan did not affect sperm motility in vitro or in vivo, suggesting reinforcement of the mucus physical barrier as the primary mechanism of action. The chitosan formulations did not damage or irritate the ewe vaginal epithelium, in contrast to nonoxynol-9 spermicide. The demonstration that cervical mucus can be reinforced topically to create an effective barrier to sperm may therefore form the technological basis for muco-cervical barrier contraceptives with the potential to become an alternative to hormonal contraceptives.
ACS Applied Materials & Interfaces, Nov 14, 2019
The many interesting properties of chitosan polysaccharides have prompted their extensive use as ... more The many interesting properties of chitosan polysaccharides have prompted their extensive use as biomaterial building blocks, for instance as antimicrobial coatings, tissue engineering scaffolds, and drug delivery vehicles. The translation of these chitosan-based systems to the clinic still requires a deeper understanding of their safety profiles. For instance, the widespread claim that chitosans are spermicidal is supported by little to no data. Herein, we thoroughly investigate whether chitosan oligomer (CO) molecules can impact the functional and structural features of human spermatozoa. By using a large number of primary sperm cell samples and by isolating the effect of chitosan from the effect of sperm dissolution buffer, we provide the first realistic and complete picture of the effect of chitosans on sperms. We found that CO binds to cell surfaces or/and is internalized by cells and affected the average path velocity of the spermatozoa, in a dose-dependent manner. However, CO did not affect the progressive motility, motility, or sperm morphology, nor did it cause loss of plasma membrane integrity, reactive oxygen species production, or DNA damage. A decrease in spermatozoa adenosine triphosphate levels, which was especially significant at higher CO concentrations, points to possible interference of CO with mitochondrial functions or the glycolysis processes. With this first complete and in-depth look at the spermicidal activities of chitosans, we complement the complex picture of the safety profile of chitosans and inform on further use of chitosans in biomedical applications.
Zenodo (CERN European Organization for Nuclear Research), Nov 30, 2022
Close to half of the world's pregnancies are still unplanned, reflecting a clear unmet need in co... more Close to half of the world's pregnancies are still unplanned, reflecting a clear unmet need in contraception. Ideally, a contraceptive would provide the high efficacy of hormonal treatments, without the systemic side effects of hormones. Here we propose topical reinforcement of the cervical mucus by chitosan mucoadhesive polymers as a form of female contraceptive. Chitosans larger than 7 kDa effectively crosslinked human ovulatory cervical mucus to prevent sperm penetration in vitro. We then demonstrated in vivo using the ewe as a model that vaginal gels containing chitosan could stop ram sperm at the entrance of the cervical canal and prevent them from reaching the uterus, whereas the same gels without chitosan did not significantly limit sperm migration. The chitosan did not affect sperm motility in vitro or in vivo, suggesting reinforcement of the mucus physical barrier as the primary mechanism of action. The chitosan formulations did not damage or irritate the ewe vaginal epithelium, in contrast to nonoxynol-9 spermicide. The demonstration that cervical mucus can be reinforced topically to create an effective barrier to sperm may therefore form the technological basis for muco-cervical barrier contraceptives with the potential to become an alternative to hormonal contraceptives.
Semen analysis is central in infertility investigation. Manual assessment of sperm motility accor... more Semen analysis is central in infertility investigation. Manual assessment of sperm motility according to the WHO recommendations is the golden standard, and extensive training is a requirement for accurate and reproducible results. Deep convolutional neural networks (DCNN) are especially suitable for image classification. In this study, we evaluated the performance of DCNN models in predicting the proportion of sperm in the WHO motility categories. The models were evaluated using 10-fold cross-validation with 65 video recordings of wet semen preparations from individual men and corresponding manually assessed data obtained from an external quality assessment programme for semen analysis. The convolutional neural network used was ResNet-50. One model was trained to predict the three categories progressive motility, non-progressive motility, and immotile spermatozoa. Another model was used in predicting four categories, where progressive motility was differentiated into rapid and slow...
Human Reproduction, 2021
Study question How can an automation & artificial intelligent tools be developed to perform accor... more Study question How can an automation & artificial intelligent tools be developed to perform according to WHO recommendations? Summary answer Developing CASA performs at < 20% error margin requires AI trained with high quality datasets and a robotic system adheres to WHO guidelines. What is known already A survey of 40 andrology laboratories, in 22 countries, revealed that > 90% had nonconformities in correct use of equipment, standardisation of protocols and quality control, leading to a lack of compliance to WHO protocols. Conventional CASA systems can standardize analysis, but controversy has occurred due to differences between manual and automated analyses stemming from: 1) all cells in a semen sample are detected including debris; 2) protocol variation when compared to top-notch manual analysis. The first point can be addressed by AI. The second point can be addressed by robotics designed to adhere to WHO guidelines. Study design, size, duration A mojo AISA (AI-powered sem...
Human Reproduction, 2021
Study question Can a CASA system based on Artificial Intelligence perform as well as manual semen... more Study question Can a CASA system based on Artificial Intelligence perform as well as manual semen assessment, within the WHO error margins? Summary answer The AI-based CASA systems that mimic high quality assessments show great potential for reducing clinical workloads while increasing treatment efficacy. What is known already The field of male-factor fertility investigation is still lacking an automated semen analysis system that can be widely clinically adopted. By leveraging state-of-the-art robotics and Artificial Intelligence (AI), it was possible to build mojo AISA which is an AI and robotic platform designed according to WHO recommendation for semen analysis. This system is based on AI software with a unique convolutional neural network (CNN) that detects and measures sperm concentration and motility while ruling out unwanted cells and debris in raw samples. Study design, size, duration This study presents and validates the mojo AISA device. A total of 60 patient samples at A...
Human Reproduction, 2011
background: External quality assessment is essential in modern andrology laboratories. To assess ... more background: External quality assessment is essential in modern andrology laboratories. To assess the proficiency of laboratories participating in an external quality assessment programme (EQAP), limits for acceptable variability must be determined. Limits currently specified largely depend on criteria set by the organizers of individual EQAP schemes. The objective of this study was to evaluate the different criteria described in ISO 13528:2005 for calculating acceptable variability in EQAP when applied to basic semen analysis parameters. methods and results: The data used in this study were the means and standard deviations obtained for independent samples from two EQAPs, one national (Spanish) and one international (European). The acceptable variability according to ISO 13528:2005 was calculated using four types of criteria: (i) +3 standard deviations of the results of all participating laboratories; (ii) +3 standard deviations of the results of expert laboratories; (iii) quality specifications based on biological variability, state-of-the-art and clinicians' opinions and (iv) the same quality specifications adjusted for the uncertainty of the assigned value. The first two strategies resulted in very wide ranges of acceptable variability. Conversely, the strategy based only on quality specifications resulted in very narrow ranges. For the fourth strategy, acceptable ranges were intermediate between the results produced with the other strategies. The third and fourth strategies did not produce observable differences in acceptable ranges when the model used for calculating the specifications of analytical quality was changed. conclusions: It is essential that EQAPs for semen parameters should determine the ranges for acceptable variability in results. Moreover, these ranges must be clinically useful, i.e. the variability should have a minimal negative impact on clinical decisions. The exact definition of 'expert laboratory' is more important than the model chosen for estimating analytical quality specifications in an EQAP for semen parameters in basic semen analysis.
Human Reproduction
Biomedical science is rapidly developing in terms of more transparency, openness and reproducibil... more Biomedical science is rapidly developing in terms of more transparency, openness and reproducibility of scientific publications. This is even more important for all studies that are based on results from basic semen examination. Recently two concordant documents have been published: the 6th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, and the International Standard ISO 23162:2021. With these tools, we propose that authors should be instructed to follow these laboratory methods in order to publish studies in peer-reviewed journals, preferable by using a checklist as suggested in an Appendix to this article.
Reproductive BioMedicine Online, 2015
Pim Janssens is a senior clinical chemist. He studied biochemistry in Amsterdam, obtained a PhD i... more Pim Janssens is a senior clinical chemist. He studied biochemistry in Amsterdam, obtained a PhD in science, and went on to train as a clinical chemist. He is specialized in inborn errors of metabolism. He was laboratory director of the Department of Clinical Chemistry and Haematology & Semen Bank at Rijnstate Hospital for 6 years, with an interest in exploring the professional, organizational and ethical aspects of gamete donation. Pim Janssens has been the chairman of the Dutch Society of Semen Banks for more than 10 years, and has published articles on gamete donation, laboratory organization, test ordering management and risk assessment and management.
Scandinavian Journal of Urology and Nephrology, 1988
The stability and the content of zinc of the chromatin were studied in spermatozoa from ten men w... more The stability and the content of zinc of the chromatin were studied in spermatozoa from ten men with unexplained infertility, and in spermatozoa from five fertile donors. A positive relation was found between zinc in sperm nuclei (X-ray microanalysis) and the resistance of the chromatin to decondense in sodium dodecylsulfate (SDS). The infertile men had lower degree of sperm chromatin stability and lower sperm zinc content than the fertile donors. A subgroup of the infertile men, which all had minor clinical signs of prostatic inflammatory reaction, had the lowest content of zinc in the chromatin and the lowest degree of chromatin stability. A low content of nuclear zinc would impair the structural stability of the chromatin and thereby increase the vulnerability of the male genome. This mechanism may be one explanation for the reduced fertility of the men with minor inflammation of the prostate.
Human Reproduction, 2011
Introduction: Urogenital infections have been known to play an important role in male fertility d... more Introduction: Urogenital infections have been known to play an important role in male fertility disorders. Data concerning the contribution of herpes simplex virus (HSV) in etiology of male infertility are controversial. The aim of present study was to evaluate HSV influence on male germ cells in sperm samples and in the testis organotypic culture. Material and Methods: 93 sperm samples from men attending infertility clinic and 49 samples from sperm donors were studied by rapid culture method (RCM) and by polymerase chain reaction in situ (PCR-in situ) to detect HSV. To evaluate HSV influence on major sperm parameters semen analysis was performed. In order to reveal HSV impact on immature germ cells human testis organotypic culture was obtained, infected and studied during 14 days. Results: Infectious HSV was found in 20,4% of samples from infertile men and in 6,1% of probes from healthy donors (p < 0.05). HSV DNA was detected in 26,9% and 2% of samples, respectively (p < 0.05). Percentage of motile spermatozoa and of gametes with normal morphology was lower in HSV-infected samples comparing with uninfected ones: 21% vs 40% (p < 0.05) and 13% vs 19% (p < 0.05), respectively. Concentration of gametes didn't differ among these groups. Morphological studies of HSV-infected and uninfected human organotypic culture revealed significant decrease in population of spermatogonia, spermatocytes and spermatides, but not in spermatozoa. Conclusions: The data obtained suppose that HSV is more frequently detected in sperm of infertile men than in healthy ones. Decrease in immature germ cells population and decline in number of mature gametes with normal motility and morphology-are possible mechanism of HSV-associated fertility disorders. P-003 Comet assay profile of single and double-strand sperm DNA damage in different patient groups