Enhanced Recovery After Surgery (ERAS®) Society Consensus Guidelines for Emergency Laparotomy Part 3: Organizational Aspects and General Considerations for Management of the Emergency Laparotomy Patient.

BACKGROUND: This is Part 3 of the first consensus guidelines for optimal care of patients undergoing emergency laparotomy using an enhanced recovery after surgery (ERAS) approach. This paper addresses organizational aspects of care. METHODS: Experts in management of the high-risk and emergency general surgical patient were invited to contribute by the International ERAS® Society. PubMed, Cochrane, Embase, and MEDLINE database searches were performed for ERAS elements and relevant specific topics. Studies were selected with particular attention to randomized clinical trials, systematic reviews, meta-analyses and large cohort studies, and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation system. Recommendations were made on the best level of evidence, or extrapolation from studies on elective patients when appropriate. A modified Delphi method was used to validate final recommendations. RESULTS: Components of organizational aspects of care were considered. Consensus was reached after three rounds of a modified Delphi process. CONCLUSIONS: These guidelines are based on best current available evidence for organizational aspects of an ERAS® approach to patients undergoing emergency laparotomy and include discussion of less common aspects of care for the surgical patient, including end-of-life issues. These guidelines are not exhaustive but pull together evidence on important components of care for this high-risk patient population. As much of the evidence is extrapolated from elective surgery or emergency general surgery (not specifically laparotomy), many of the components need further evaluation in future studies.

Consensus Guidelines for Perioperative Care for Emergency Laparotomy Enhanced Recovery After Surgery (ERAS®) Society Recommendations Part 2-Emergency Laparotomy: Intra- and Postoperative Care.

BACKGROUND: This is Part 2 of the first consensus guidelines for optimal care of patients undergoing emergency laparotomy (EL) using an Enhanced Recovery After Surgery (ERAS) approach. This paper addresses intra- and postoperative aspects of care. METHODS: Experts in aspects of management of high-risk and emergency general surgical patients were invited to contribute by the International ERAS® Society. PubMed, Cochrane, Embase, and Medline database searches were performed for ERAS elements and relevant specific topics. Studies on each item were selected with particular attention to randomized clinical trials, systematic reviews, meta-analyses, and large cohort studies and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Recommendations were made on the best level of evidence, or extrapolation from studies on elective patients when appropriate. A modified Delphi method was used to validate final recommendations. Some ERAS® components covered in other guideline papers are outlined only briefly, with the bulk of the text focusing on key areas pertaining specifically to EL. RESULTS: Twenty-three components of intraoperative and postoperative care were defined. Consensus was reached after three rounds of a modified Delphi Process. CONCLUSIONS: These guidelines are based on best available evidence for an ERAS® approach to patients undergoing EL. These guidelines are not exhaustive but pull together evidence on important components of care for this high-risk patient population. As much of the evidence is extrapolated from elective surgery or emergency general surgery (not specifically laparotomy), many of the components need further evaluation in future studies.

Standards in semen examination: publishing reproducible and reliable data based on high-quality methodology.

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.

OXIDATIVE STRESS AND REPRODUCTIVE FUNCTION: Sperm telomeres, oxidative stress, and infertility.

In brief: Oxidative stress is recognized as an underlying driving factor of both telomere dysfunction and human subfertility/infertility. This review briefly reassesses telomere integrity as a fertility biomarker before proposing a novel, mechanistic rationale for the role of oxidative stress in the seemingly paradoxical lengthening of sperm telomeres with aging. Abstract: The maintenance of redox balance in the male reproductive tract is critical to sperm health and function. Physiological levels of reactive oxygen species (ROS) promote sperm capacitation, while excess ROS exposure, or depleted antioxidant defenses, yields a state of oxidative stress which disrupts their fertilizing capacity and DNA structural integrity. The guanine moiety is the most readily oxidized of the four DNA bases and gets converted to the mutagenic lesion 8-hydroxy-deoxyguanosine (8-OHdG). Numerous studies have also confirmed oxidative stress as a driving factor behind accelerated telomere shortening and dysfunction. Although a clear consensus has not been reached, clinical studies also appear to associate telomere integrity with fertility outcomes in the assisted reproductive technology setting. Intriguingly, while sperm cellular and molecular characteristics make them more susceptible to oxidative insult than any other cell type, they are also the only cell type in which telomere lengthening accompanies aging. This article focuses on the oxidative stress response pathways to propose a mechanism for the explanation of this apparent paradox.

Guidelines for Perioperative Care for Emergency Laparotomy Enhanced Recovery After Surgery (ERAS) Society Recommendations: Part 1-Preoperative: Diagnosis, Rapid Assessment and Optimization.

BACKGROUND: Enhanced Recovery After Surgery (ERAS) protocols reduce length of stay, complications and costs for a large number of elective surgical procedures. A similar, structured approach appears to improve outcomes, including mortality, for patients undergoing high-risk emergency general surgery, and specifically emergency laparotomy. These are the first consensus guidelines for optimal care of these patients using an ERAS approach. METHODS: Experts in aspects of management of the high-risk and emergency general surgical patient were invited to contribute by the International ERAS® Society. Pubmed, Cochrane, Embase, and MEDLINE database searches on English language publications were performed for ERAS elements and relevant specific topics. Studies on each item were selected with particular attention to randomized controlled trials, systematic reviews, meta-analyses and large cohort studies, and reviewed and graded using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. Recommendations were made on the best level of evidence, or extrapolation from studies on non-emergency patients when appropriate. The Delphi method was used to validate final recommendations. The guideline has been divided into two parts: Part 1-Preoperative Care and Part 2-Intraoperative and Postoperative management. This paper provides guidelines for Part 1. RESULTS: Twelve components of preoperative care were considered. Consensus was reached after three rounds. CONCLUSIONS: These guidelines are based on the best available evidence for an ERAS approach to patients undergoing emergency laparotomy. Initial management is particularly important for patients with sepsis and physiological derangement. These guidelines should be used to improve outcomes for these high-risk patients.

Occupational Inhalation Exposures to Nanoparticles at Six Singapore Printing Centers.

Laser printers emit high levels of nanoparticles (PM0.1) during operation. Although it is well established that toners contain multiple engineered nanomaterials (ENMs), little is known about inhalation exposures to these nanoparticles and work practices in printing centers. In this report, we present a comprehensive inhalation exposure assessment of indoor microenvironments at six commercial printing centers in Singapore, the first such assessment outside of the United States, using real-time personal and stationary monitors, time-integrated instrumentation, and multiple analytical methods. Extensive presence of ENMs, including titanium dioxide, iron oxide, and silica, was detected in toners and in airborne particles collected from all six centers studied. We document high transient exposures to emitted nanoparticles (peaks of ∼500 000 particles/cm3, lung-deposited surface area of up to 220 µm2/cm3, and PM0.1 up to 16 µg/m3) with complex PM0.1 chemistry that included 40-60 wt % organic carbon, 10-15 wt % elemental carbon, and 14 wt % trace elements. We also record 271.6-474.9 pmol/mg of Environmental Protection Agency-priority polycyclic aromatic hydrocarbons. These findings highlight the potentially high occupational inhalation exposures to nanoparticles with complex compositions resulting from widespread usage of nano-enabled toners in the printing industry, as well as inadequate ENM-specific exposure control measures in these settings.

Depletion of thiols leads to redox deregulation, production of 4-hydroxinonenal and sperm senescence: a possible role for GSH regulation in spermatozoa†.

We hypothesized that thiols and particularly glutathione (GSH) are essential for the regulation of stallion sperm functionality. To test this hypothesis, we initially investigated the relationship between sperm function and GSH content, revealing highly significant correlations between GSH, sperm viability, motility, and velocity parameters (P < 0.001). Furthermore, the deleterious effects of GSH depletion using menadione and 1,3 dimethoxy 1,4, naphtoquinone (DMNQ) were able to be prevented by the addition of cysteine, but no other antioxidant. Pre-incubation with cysteine prevented menadione and DMNQ induced damage to sperm membranes after 1 h (P < 0.001; P < 0.05) and after 3 h of incubation (P < 0.001, P < 0.05). Pre-incubation with cysteine ameliorated both the menadione- and DMNQ-induced increase in 4-hydroxynonenal (P < 0.001). As cysteine is a precursor of GSH, we hypothesized that stallion spermatozoa are able to synthesize this tripeptide using exogenous cysteine. To test this hypothesis, we investigated the presence of two enzymes required to synthesize GSH (GSH and GCLC) and using western blotting and immunocytochemistry we detected both enzymes in stallion spermatozoa. The inhibition of GCLC reduced the recovery of GSH by addition of cysteine after depletion, suggesting that stallion spermatozoa may use exogenous cysteine to regulate GSH. Other findings supporting this hypothesis were changes in sperm functionality after BSO treatment and changes in GSH and GSSG validated using HPLC-MS, showing that BSO prevented the increase in GSH in the presence of cysteine, although important stallion to stallion variability occurred and suggested differences in expression of glutamate cysteine ligase. Mean concentration of GSH in stallion spermatozoa was 8.2 ± 2.1 µM/109 spermatozoa, well above the nanomolar ranges per billion spermatozoa reported for other mammals.

Reactive oxygen species as mediators of sperm capacitation and pathological damage.

Oxidative stress plays a major role in the life and death of mammalian spermatozoa. These gametes are professional generators of reactive oxygen species (ROS), which appear to derive from three potential sources: sperm mitochondria, cytosolic L-amino acid oxidases, and plasma membrane Nicotinamide adenine dinucleotide phosphate oxidases. The oxidative stress created via these sources appears to play a significant role in driving the physiological changes associated with sperm capacitation through the stimulation of a cyclic adenosine monophosphate/Protein kinase A phosphorylation cascade, including the activation of Extracellular signal regulated kinase-like proteins, massive up-regulation of tyrosine phosphorylation in the sperm tail, as well as the induction of sterol oxidation. When generated in excess, however, ROS can induce lipid peroxidation that, in turn, disrupts membrane characteristics that are critical for the maintenance of sperm function, including the capacity to fertilize an egg. Furthermore, the lipid aldehydes generated as a consequence of lipid peroxidation bind to proteins in the mitochondrial electron transport chain, triggering yet more ROS generation in a self-perpetuating cycle. The high levels of oxidative stress created as a result of this process ultimately damage the DNA in the sperm nucleus; indeed, DNA damage in the male germ line appears to be predominantly induced oxidatively, reflecting the vulnerability of these cells to such stress. Extensive evaluation of antioxidants that protect the spermatozoa against oxidative stress while permitting the normal reduction-oxidation regulation of sperm capacitation is therefore currently being undertaken, and has already proven efficacious in animal models.

Evidence that fetal death is associated with placental aging.

BACKGROUND: The risk of unexplained fetal death or stillbirth increases late in pregnancy, suggesting that placental aging is an etiological factor. Aging is associated with oxidative damage to DNA, RNA, and lipids. We hypothesized that placentas at >41 completed weeks of gestation (late-term) would show changes consistent with aging that would also be present in placentas associated with stillbirths. OBJECTIVE: We sought to determine whether placentas from late-term pregnancies and unexplained stillbirth show oxidative damage and other biochemical signs of aging. We also aimed to develop an in vitro term placental explant culture model to test the aging pathways. STUDY DESIGN: We collected placentas from women at 37-39 weeks' gestation (early-term and term), late-term, and with unexplained stillbirth. We used immunohistochemistry to compare the 3 groups for: DNA/RNA oxidation (8-hydroxy-deoxyguanosine), lysosomal distribution (lysosome-associated membrane protein 2), lipid oxidation (4-hydroxynonenal), and autophagosome size (microtubule-associated proteins 1A/1B light chain 3B, LC3B). The expression of aldehyde oxidase 1 was measured by real-time polymerase chain reaction. Using a placental explant culture model, we tested the hypothesis that aldehyde oxidase 1 mediates oxidative damage to lipids in the placenta. RESULTS: Placentas from late-term pregnancies show increased aldehyde oxidase 1 expression, oxidation of DNA/RNA and lipid, perinuclear location of lysosomes, and larger autophagosomes compared to placentas from women delivered at 37-39 weeks. Stillbirth-associated placentas showed similar changes in oxidation of DNA/RNA and lipid, lysosomal location, and autophagosome size to placentas from late-term. Placental explants from term deliveries cultured in serum-free medium also showed evidence of oxidation of lipid, perinuclear lysosomes, and larger autophagosomes, changes that were blocked by the G-protein-coupled estrogen receptor 1 agonist G1, while the oxidation of lipid was blocked by the aldehyde oxidase 1 inhibitor raloxifene. CONCLUSION: Our data are consistent with a role for aldehyde oxidase 1 and G-protein-coupled estrogen receptor 1 in mediating aging of the placenta that may contribute to stillbirth. The placenta is a tractable model of aging in human tissue.

Aldehyde Dehydrogenase Plays a Pivotal Role in the Maintenance of Stallion Sperm Motility.

Although stallion spermatozoa produce significant quantities of reactive oxygen species, a lag between 4-hydroxynonenal (4HNE) adduction and the loss of motility in stallion spermatozoa suggests the presence of a robust aldehyde detoxification mechanism. Because there is a paucity of studies characterizing the role of aldehyde dehydrogenase (ALDH) in sperm functionality, the aim of this study was to ascertain the relationship between 4HNE production and motility and ALDH expression by stallion spermatozoa. PCR analysis revealed the presence of the ALDH1A3, ALDH1B1, and ALDH2 isoforms in these cells. Strong correlations (P < 0.001) were found between ALDH expression and various motility parameters of stallion spermatozoa including the percentage of progressive (r = 0.79) and rapidly motile (r = 0.79) spermatozoa, whereas repeated measurements over 24 h revealed highly significant correlations among progressive motility loss, 4HNE accumulation, and ALDH expression (P ≤ 0.001). ALDH inhibition resulted in a spontaneous increase in 4HNE levels in viable cells (21.1 ± 5.8% vs. 42.6 ± 5.2%; P ≤ 0.05) and a corresponding decrease in total motility (41.7 ± 6.2% vs. 6.4 ± 2.6%; P ≤ 0.001) and progressive motility (17.0 ± 4.1% vs. 0.7 ± 0.4%; P ≤ 0.001) of stallion spermatozoa over 24 h. Similarly, inhibition of ALDH in 4HNE-challenged spermatozoa significantly reduced total motility over 4 h (35.4 ± 9.7% vs. 15.3 ± 5.1%, respectively; P ≤ 0.05). This study contributes valuable information about the role of the ALDH enzymes in the maintenance of stallion sperm functionality, with potential diagnostic and in vitro applications for assisted reproductive technologies.

The presence of a truncated base excision repair pathway in human spermatozoa that is mediated by OGG1.

DNA repair has long been considered impossible in human spermatozoa due to the high level of DNA compaction observed in these cells. However, detailed examination of the base excision repair pathway in human spermatozoa has revealed the presence of an enzyme critical to this pathway, 8-oxoguanine DNA glycosylase 1 (OGG1). This glycosylase was associated with the sperm nucleus and mitochondria and could actively excise 8-hydroxy-2'-deoxyguanosine (8OHdG), releasing this adduct into the extracellular space. This activity was significantly reduced in the presence of cadmium (II), a recognized inhibitor of OGG1, in a time- and dose-dependent manner (P<0.001). Remarkably, spermatozoa do not possess the downstream components of the base excision repair pathway, apurinic endonuclease 1 (APE1) and X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1). The absence of these proteins was particularly significant, as APE1 is required to create a 3'-hydroxyl (3'-OH) terminus at the apurinic site created by OGG1, which would be recognized by the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. As a result, TUNEL was unable to detect oxidatively induced DNA damage in spermatozoa following exposure to hydrogen peroxide. In the same cells, intracellular and extracellular 8OHdG could be clearly detected in a manner that was highly correlated with the outcome of the sperm chromatin structure assay (SCSA). However, incubation of these cells for 48 hours revealed a time-dependent increase in TUNEL positivity, suggesting the perimortem activation of a nuclease. These results emphasize the limited capacity of mature spermatozoa to mount a DNA repair response to oxidative stress, and highlight the importance of such mechanisms in the oocyte in order to protect the embryo from paternally mediated genetic damage.

L-carnitine and pyruvate are prosurvival factors during the storage of stallion spermatozoa at room temperature.

The spermatozoa of many stallions do not tolerate being cooled, restricting the commercial viability of these animals and necessitating the development of a chemically defined room temperature (RT) storage medium. This study examined the impact of two major modulators of oxidative phosphorylation, pyruvate (Pyr) and L-carnitine (L-C), on the storage of stallion spermatozoa at RT. Optimal concentrations of Pyr (10 mM) and L-C (50 mM) were first identified and these concentrations were then used to investigate the effects of these compounds on sperm functionality and oxidative stress at RT. Mitochondrial and cytosolic reactive oxygen species, along with lipid peroxidation, were all significantly suppressed by the addition of L-C (48 h MitoSOX Red negative: 46.2% vs. 26.1%; 48 and 72 h dihydroethidium negative: 61.6% vs. 43.1% and 64.4% vs. 46.9%, respectively; 48 and 72 h 4-hydroxynonenal negative: 37.1% vs. 23.8% and 41.6% vs. 25.7%, respectively), while the Pyr + L-C combination resulted in significantly higher motility compared to the control at 72 h (total motility: 64.2% vs. 39.4%; progressive motility: 34.2% vs. 15.2%). In addition, supplementation with L-C significantly reduced oxidative DNA damage at 72 h (9.0% vs. 15.6%). To investigate the effects of L-C as an osmolyte, comparisons were made between media that were osmotically balanced with NaCl, choline chloride, or L-C. This analysis demonstrated that spermatozoa stored in the L-C balanced medium had significantly higher total motility (55.0% vs. 39.0%), rapid motility (44.0% vs. 25.7%), and ATP levels (70.9 vs. 12.8 ng/ml) following storage compared with the NaCl treatment, while choline chloride did not significantly improve these parameters compared to the control. Finally, mass spectrometry was used to demonstrate that a combination of Pyr and L-C produced significantly higher acetyl-L-carnitine production than any other treatment (6.7 pg/10(6) spermatozoa vs. control at 4.0 pg/10(6) spermatozoa). These findings suggest that Pyr and L-C could form the basis of a novel, effective RT storage medium for equine spermatozoa.

Sperm DNA fragmentation abnormalities in men from couples with a history of recurrent miscarriage.

BACKGROUND: Previous studies have described an association between sperm with DNA damage and a history of recurrent miscarriage (RM), although it is not clear whether there is benefit in screening for sperm DNA fragmentation and to what extent DNA fragmentation impacts upon RM. AIMS: To identify what proportion of couples experiencing RM are affected by DNA fragmentation abnormalities. MATERIALS AND METHODS: In this retrospective study, between 2008 and 2013, couples with a history of recurrent miscarriage (≥3 first trimester miscarriages) were investigated comprehensively for known causes (karyotype, uterine, antiphospholipid syndrome, thrombophilia) and also by semen analysis, including DNA fragmentation [sperm chromatin structure analysis (SCSA)]. Statistical analysis was performed on SPSS software with significance taken as P < 0.05. RESULTS: There were 108 couples with a median sperm DNA fragmentation index (DFI) of 9.50%. Normal levels were found in 70.5% of men (DFI < 15%), 23% had high levels (DFI 15-30%), and 6.5% had very high levels (DFI > 30%). Couples with otherwise unexplained recurrent miscarriage had significantly higher DFI than those with other causes identified on routine screening (P = 0.012). CONCLUSIONS: In couples experiencing RM, 30% (32/108) of men had sperm with high levels of DNA fragmentation (DFI > 15%). This may be a contributing factor to the clinical syndrome of RM, and future clinical trials of therapies for these couples are warranted.

The paradoxical relationship between stallion fertility and oxidative stress.

The relationship between stallion fertility and oxidative stress remains poorly understood. The purpose of this study was to identify criteria for thoroughbred fertility assessment by performing a logistical regression analysis using "dismount" sperm parameters as predictors and weekly per-cycle conception rate as the dependent variable. Paradoxically, positive relationships between fertility and oxidative stress were revealed, such that samples that produced pregnancies exhibited higher rates of 8-hydroxy-2'-deoxyguanosine release (1490.2% vs. 705.5 pg/ml/24 h) and lower vitality (60.5% vs. 69.6%) and acrosome integrity (40.2% vs. 50.1%) than those that did not. We hypothesized that the most fertile spermatozoa exhibited the highest levels of oxidative phosphorylation (OXPHOS), with oxidative stress simply being a by-product of intense mitochondrial activity. Accordingly, an experiment to investigate the relationship between oxidative stress and motility was conducted and revealed positive correlations between mitochondrial ROS and total motility (R² = 0.90), rapid motility (R² = 0.89), average path velocity (VAP; R² = 0.59), and curvilinear velocity (VCL; R² = 0.66). Similarly, lipid peroxidation was positively correlated with total motility (R² = 0.46), rapid motility (R² = 0.51), average path velocity (R² = 0.62), and VCL (R² = 0.56), supporting the aforementioned hypothesis. The relative importance of OXPHOS in supporting the motility of equine spermatozoa was contrasted with human spermatozoa, which primarily utilize glycolysis. In this study, mitochondrial inhibition significantly reduced the velocity (P < 0.01) and ATP (P < 0.05) content of equine, but not human, spermatozoa, emphasizing the former's relative dependence on OXPHOS. The equine is the first mammal in which such a positive relationship between oxidative stress and functionality has been observed, with implications for the management of stallion fertility in vitro and in vivo.

Addition of Vitamin C Mitigates the Loss of Antioxidant Capacity, Vitality and DNA Integrity in Cryopreserved Human Semen Samples.

Cryopreservation of human spermatozoa is a necessity for males suffering from infertility who cannot produce fresh semen for insemination. However, current ART cryopreservation protocols are associated with losses of sperm motility, vitality and DNA integrity, which are thought to be linked to the induction of oxidative damage and the toxic properties of commercial cryoprotectants (CPAs). Preventing or mitigating these losses would be hugely beneficial to sperm survival during ART. Therefore, in this in vitro investigation, lipid peroxidation, production of reactive oxygen species, movement characteristics, antioxidant capacity, vitality, and DNA integrity were examined in semen samples both pre- and post-cryopreservation with CPA supplementation. The findings revealed a 50% reduction in antioxidant capacity with CPA addition, which was accompanied by significant increases in generation of reactive oxygen species and formation of lipid aldehydes. These changes were, in turn, correlated with reductions in sperm viability, motility and DNA integrity. Antioxidant supplementation generated bell-shaped dose-response curves with both resveratrol and vitamin C, emphasising the vulnerability of these cells to both oxidative and reductive stress. At the optimal dose, vitamin C was able to significantly enhance vitality and reduce DNA damage recorded in cryopreserved human spermatozoa. An improvement in sperm motility did not reach statistical significance, possibly because additional pathophysiological mechanisms limit the potential effectiveness of antioxidants in rescuing this aspect of sperm function. The vulnerability of human spermatozoa to reductive stress and the complex nature of sperm cryoinjury will present major challenges in creating the next generation of cryoprotective media.

The effects of oxidative stress and intracellular calcium on mitochondrial permeability transition pore formation in equine spermatozoa.

The in vitro storage of stallion spermatozoa for use in artificial insemination leads to oxidative stress and imbalances in calcium homeostasis that trigger the formation of the mitochondrial permeability transition pore (mPTP), resulting in premature cell death. However, little is understood about the dynamics and the role of mPTP formation in mammalian spermatozoa. Here, we identify an important role for mPTP in stallion sperm Ca2+ homeostasis. We show that stallion spermatozoa do not exhibit "classical" features of mPTP; specifically, they are resistant to cyclosporin A-mediated inhibition of mPTP formation, and they do not require exogenous Ca2+ to form the mPTP. However, chelation of endogenous Ca2+ prevented mPTP formation, indicating a role for intracellular Ca2+ in this process. Furthermore, our findings suggest that this cell type can mobilize intracellular Ca2+ stores to form the mPTP in response to low Ca2+ environments and that under oxidative stress conditions, mPTP formation preceded a measurable increase in intracellular Ca2+, and vice versa. Contrary to previous work that identified mitochondrial membrane potential (MMP) as a proxy for mPTP formation, here we show that a loss of MMP can occur independently of mPTP formation, and thus MMP is not an appropriate proxy for the detection of mPTP formation. In conclusion, the mPTP plays a crucial role in maintaining Ca2+ and reactive oxygen species homeostasis in stallion spermatozoa, serving as an important regulatory mechanism for normal sperm function, thereby contraindicating the in vitro pharmacological inhibition of mPTP formation to enhance sperm longevity.

Governance of advanced materials: Shaping a safe and sustainable future.

The past few decades of managing the uncertain risks associated with nanomaterials have provided valuable insights (knowledge gaps, tools, methods, etc.) that are equally important to promote safe and sustainable development and use of advanced materials. Based on these insights, the current paper proposes several actions to optimize the risk and sustainability governance of advanced materials. We emphasise the importance of establishing a European approach for risk and sustainability governance of advanced materials as soon as possible to keep up with the pace of innovation and to manage uncertainty among regulators, industry, SMEs and the public, regarding potential risks and impacts of advanced materials. Coordination of safe and sustainable advanced material research efforts, and data management according to the Findable, Accessible, Interoperable and Reusable (FAIR) principles will enhance the generation of regulatory-relevant knowledge. This knowledge is crucial to identify whether current regulatory standardised and harmonised test methods are adequate to assess advanced materials. At the same time, there is urgent need for responsible innovation beyond regulatory compliance which can be promoted through the Safe and Sustainable Innovation Approach. that combines the Safe and Sustainable by Design concept with Regulatory Preparedness, supported by a trusted environment. We further recommend consolidating all efforts and networks related to the risk and sustainability governance of advanced materials in a single, easy-to-use digital portal. Given the anticipated complexity and tremendous efforts required, we identified the need of establishing an organisational structure dedicated to aligning the fast technological developments in advanced materials with proper risk and sustainability governance. Involvement of multiple stakeholders in a trusted environment ensures a coordinated effort towards the safe and sustainable development, production, and use of advanced materials. The existing infrastructures and network of experts involved in the governance of nanomaterials would form a solid foundation for such an organisational structure.