Mortality and morbidity after total intravenous anaesthesia versus inhalational anaesthesia: a systematic review and meta-analysis.

Background: General anaesthesia is provided to more than 300 million surgical patients worldwide, every year. It is administered either through total intravenous anaesthesia, using only intravenous agents, or through inhalational anaesthesia, using volatile anaesthetic agents. The debate on how this affects postoperative patient outcome is ongoing, despite an abundance of published trials. The relevance of this topic has grown by the increasing concern about the contribution of anaesthetic gases to the environmental impact of surgery. We aimed to summarise all available evidence on relevant patient outcomes with total intravenous anaesthesia versus inhalational anaesthesia. Methods: In this systematic review and meta-analysis, we searched PubMed/Medline, Embase and Cochrane Central Register of Controlled trials for works published from January 1, 1985 to August 1, 2023 for randomised controlled trials comparing total intravenous anaesthesia using propofol versus inhalational anaesthesia using the volatile anaesthetics sevoflurane, desflurane or isoflurane. Two reviewers independently screened titles, abstracts and full text articles, and assessed risk of bias using the Cochrane Collaboration tool. Outcomes were derived from a recent series of publications on consensus definitions for Standardised Endpoints for Perioperative trials (StEP). Primary outcomes covered mortality and organ-related morbidity. Secondary outcomes were related to anaesthetic and surgical morbidity. This study is registered with PROSPERO (CRD42023430492). Findings: We included 317 randomised controlled trials, comprising 51,107 patients. No difference between total intravenous and inhalational anaesthesia was seen in the primary outcomes of in-hospital mortality (RR 1.05, 95% CI 0.67-1.66, 27 trials, 3846 patients), 30-day mortality (RR 0.97, 95% CI 0.70-1.36, 23 trials, 9667 patients) and one-year mortality (RR 1.14, 95% CI 0.88-1.48, 13 trials, 9317 patients). Organ-related morbidity was similar between groups except for the subgroup of elderly patients, in which total intravenous anaesthesia was associated with a lower incidence of postoperative cognitive dysfunction (RR 0.62, 95% CI 0.40-0.97, 11 trials, 3834 patients) and a better score on postoperative cognitive dysfunction tests (standardised mean difference 1.68, 95% CI 0.47-2.88, 9 trials, 4917 patients). In the secondary outcomes, total intravenous anaesthesia resulted in a lower incidence of postoperative nausea and vomiting (RR 0.61, 95% CI 0.56-0.67, 145 trials, 23,172 patients), less emergence delirium (RR 0.40, 95% CI 0.29-0.56, 32 trials, 4203 patients) and a higher quality of recovery score (QoR-40 mean difference 6.45, 95% CI 3.64-9.25, 17 trials, 1835 patients). Interpretation: The results indicate that postoperative mortality and organ-related morbidity was similar for intravenous and inhalational anaesthesia. Total intravenous anaesthesia offered advantages in postoperative recovery. Funding: Dutch Society for Anaesthesiology (NVA).

Do medical specialists accept claims-based Audit and Feedback for quality improvement? A focus group study.

OBJECTIVES: Audit and Feedback (A&F) is a widely used quality improvement (QI) intervention in healthcare. However, not all feedback is accepted by professionals. While claims-based feedback has been previously used for A&F interventions, its acceptance by medical specialists is largely unknown. This study examined medical specialists' acceptance of claims-based A&F for QI. DESIGN: Qualitative design, with focus group discussions. Transcripts were analysed using discourse analysis. SETTING AND PARTICIPANTS: A total of five online focus group discussions were conducted between April 2021 and September 2022 with 21 medical specialists from varying specialties (urology; paediatric surgery; gynaecology; vascular surgery; orthopaedics and trauma surgery) working in academic or regional hospitals in the Netherlands. RESULTS: Participants described mixed views on using claims-based A&F for QI. Arguments mentioned in favour were (1) A&F stimulates reflective learning and improvement and (2) claims-based A&F is more reliable than other A&F. Arguments in opposition were that (1) A&F is insufficient to create behavioural change; (2) A&F lacks clinically meaningful interpretation; (3) claims data are invalid for feedback on QI; (4) claims-based A&F is unreliable and (5) A&F may be misused by health insurers. Furthermore, participants described several conditions for the implementation of A&F which shape their acceptance. CONCLUSIONS: Using claims-based A&F for QI is, for some clinical topics and under certain conditions, accepted by medical specialists. Acceptance of claims-based A&F can be shaped by how A&F is implemented into clinical practice. When designing A&F for QI, it should be considered whether claims data, as the most resource-efficient data source, can be used or whether it is necessary to collect more specific data.

Influence of nitrous oxide added to general anaesthesia on postoperative mortality and morbidity: a systematic review and meta-analysis.

BACKGROUND: Nitrous oxide (N2O) is a common adjuvant to general anaesthesia. It is also a potent greenhouse gas and causes ozone depletion. We sought to quantify the influence of N2O as an adjuvant to general anaesthesia on postoperative patient outcomes. METHODS: We searched Medline, EMBASE, and Cochrane Central for works published from inception to July 6, 2023. RCTs comparing general anaesthesia with or without N2O were included. Risk ratios (RRs) and standardised mean differences (SMDs) were calculated, along with 95% confidence intervals (CIs), using a random-effects model. Outcomes were derived from the Standardised Endpoints for Perioperative Medicine (StEP) outcome set. Primary outcomes were mortality and organ-related morbidity, and secondary outcomes were anaesthetic and surgical morbidity. RESULTS: Of 3305 records, 179 full-text articles were assessed, and 71 RCTs, totalling 22 147 patients, were included in the meta-analysis. Addition of N2O to general anaesthesia did not influence postoperative mortality or most morbidity outcomes. N2O increased the incidence of atelectasis (RR 1.62, 95% CI 1.24 to 2.12) and postoperative nausea and vomiting (RR 1.27, 95% CI 1.15 to 1.40), and decreased intraoperative opioid consumption (SMD -0.19, 95% CI -0.35 to -0.04) and time to extubation (MD -2.17 min, 95% CI -3.32 to -1.03 min). CONCLUSIONS: N2O did not influence postoperative mortality or most morbidity outcomes. Considering the environmental effects of N2O, these findings confirm that current policy recommendations to limit its use do not affect patient safety. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42023443287.

Health Care Professionals' Experiences With a Mobile Self-Care Solution for Low Complex Orthopedic Injuries: Mixed Methods Study.

BACKGROUND: To cope with the rising number of patients with trauma in an already constrained Dutch health care system, Direct Discharge (DD) has been introduced in over 25 hospitals in the Netherlands since 2019. With DD, no routine follow-up appointments are scheduled after the emergency department (ED) visit, and patients are supported through information leaflets, a smartphone app, and a telephone helpline. DD reduces secondary health care use, with comparable patient satisfaction and primary health care use. Currently, little is known about the experiences of in-hospital health care professionals with DD. OBJECTIVE: The aim of this study was to explore the experiences of health care professionals with the DD protocol to enhance durable adoption and improve the protocol. METHODS: We conducted a mixed methods study parallel to the implementation of DD in 3 hospitals. Data were collected through a preimplementation survey, a postimplementation survey, and semistructured interviews. Quantitative data were reported descriptively, and qualitative data were reported using thematic analysis. Outcomes included the Bowen feasibility parameters: implementation, acceptability, preliminary efficacy, demand, and applicability. Preimplementation expectations were compared with postimplementation experiences. Health care professionals involved in the daily clinical care of patients with low-complex, stable injuries were eligible for this study. RESULTS: Of the 217 eligible health care professionals, 128 started the primary survey, 37 completed both surveys (response rate of 17%), and 15 participated in semistructured interviews. Health care professionals expressed satisfaction with the DD protocol (median 7.8, IQR 6.8-8.9) on a 10-point scale, with 82% (30/37) of participants noting improved information quality and uniformity and 73% (27/37) of patients perceiving reduced outpatient follow-up and imaging. DD was perceived as safe by 79% (28/37) of participants in its current form, but a feedback system to reassure health care professionals that patients had recovered adequately was suggested to improve DD. The introduction of DD had varying effects on workload and job satisfaction among different occupations. Health care professionals expressed intentions to continue using DD due to increased efficiency, patient empowerment, and self-management. CONCLUSIONS: Health care professionals perceive DD as an acceptable, applicable, safe, and efficacious alternative to traditional treatment. A numerical in-app feedback system (eg, in-app communication tools or recovery scores) could alleviate health care professionals' concerns about adequate recovery and further improve DD protocols. DD can reduce health care use, which is important in times of constrained resources. Nonetheless, both advantages and disadvantages should be considered while evaluating this type of treatment. In the future, clinicians and policy makers can use these insights to further optimize and implement DD in clinical practice and guidelines.

Does Centralization of Radical Prostatectomy Reduce the Incidence of Postoperative Urinary Incontinence?

Background: On the basis of previous analyses of the incidence of urinary incontinence (UI) after radical prostatectomy (RP), the hospital RP volume threshold in the Netherlands was gradually increased from 20 per year in 2017, to 50 in 2018 and 100 from 2019 onwards. Objective: To evaluate the impact of hospital RP volumes on the incidence and risk of UI after RP (RP-UI). Design setting and participants: Patients who underwent RP during 2016-2020 were identified in the claims database of the largest health insurance company in the Netherlands. Incontinence was defined as an insurance claim for ≥1 pads/d. Outcome measurements and statistical analysis: The relationship between hospital RP volume (HV) and RP-UI was assessed via multivariable analysis adjusted for age, comorbidity, postoperative radiotherapy, and lymph node dissection. Results and limitations: RP-UI incidence nationwide and by RP volume category did not decrease significantly during the study period, and 5-yr RP-UI rates varied greatly among hospitals (19-85%). However, low-volume hospitals (≤120 RPs/yr) had a higher percentage of patients with RP-UI and higher variation in comparison to high-volume hospitals (>120 RPs/yr). In comparison to hospitals with low RP volumes throughout the study period, the risk of RP-UI was 29% lower in hospitals shifting from the low-volume to the high-volume category (>120 RPs/yr) and 52% lower in hospitals with a high RP volume throughout the study period (>120 RPs/yr for 5 yr). Conclusions: A focus on increasing hospital RP volumes alone does not seem to be sufficient to reduce the incidence of RP-UI, at least in the short term. Measurement of outcomes, preferably per surgeon, and the introduction of quality assurance programs are recommended. Patient summary: In the Netherlands, centralization of surgery to remove the prostate (RP) because of cancer has not yet improved the occurrence of urinary incontinence (UI) after surgery. Hospitals performing more than 120 RP operations per year had better UI outcomes. However, there was a big difference in UI outcomes between hospitals.

What information sources do Dutch medical specialists use in medical decision-making: a qualitative interview study.

OBJECTIVE: To explore what information sources medical specialists currently use to inform their medical decision-making. DESIGN: Qualitative, semistructured interviews. SETTING AND PARTICIPANTS: A total of 20 semistructured interviews were conducted with 10 surgeons and 10 internal medicine specialists who work in academic and/or regional hospitals in the Netherlands. RESULTS: Medical specialists reported that they primarily rely on their general knowledge and experience, rather than actively using information sources. The sources they use to update their knowledge can be categorised into 'scientific publications', 'guidelines or protocols', and 'presentations and meetings'. When medical specialists feel their general knowledge and experience are insufficient, they use three different approaches to find answers in response to clinical questions: consulting a colleague, actively searching the literature and asking someone else to search the literature. CONCLUSION: Medical specialists use information sources to update their general knowledge and to find answers to specific clinical questions when they feel their general knowledge and experience are insufficient. An important finding is that medical specialists prefer accessible information sources (eg, consulting colleagues) over existing evidence-based medicine tools.

Randomized Controlled Trials in ICU in the Four Highest-Impact General Medicine Journals.

OBJECTIVE: To study ICU trials published in the four highest-impact general medicine journals by comparing them with concurrently published non-ICU trials in the same journals. DATA SOURCES: PubMed was searched for randomized controlled trials (RCTs) published between January 2014 and October 2021 in the New England Journal of Medicine , The Lancet , the Journal of the American Medical Association , and the British Medical Journal. STUDY SELECTION: Original RCT publications investigating any type of intervention in any patient population. DATA EXTRACTION: ICU RCTs were defined as RCTs exclusively including patients admitted to the ICU. Year and journal of publication, sample size, study design, funding source, study outcome, type of intervention, Fragility Index (FI), and Fragility Quotient were collected. DATA SYNTHESIS: A total of 2,770 publications were screened. Of 2,431 original RCTs, 132 (5.4%) were ICU RCTs, gradually rising from 4% in 2014 to 7.5% in 2021. ICU RCTs and non-ICU RCTs included a comparable number of patients (634 vs 584, p = 0.528). Notable differences for ICU RCTs were the low occurrence of commercial funding (5% vs 36%, p < 0.001), the low number of RCTs that reached statistical significance (29% vs 65%, p < 0.001), and the low FI when they did reach significance (3 vs 12, p = 0.008). CONCLUSIONS: In the last 8 years, RCTs in ICU medicine made up a meaningful, and growing, portion of RCTs published in high-impact general medicine journals. In comparison with concurrently published RCTs in non-ICU disciplines, statistical significance was rare and often hinged on the outcome events of just a few patients. Increased attention should be paid to realistic expectations of treatment effects when designing ICU RCTs to detect differences in treatment effects that are reliable and clinically relevant.

[Sustainability as a pillar of our healthcare system]. / Duurzaamheid als nieuwe pijler van ons zorgstelsel.

When making choices in healthcare, in addition to quality, affordability and accessibility, sustainability (climate and environmental impact) must also be taken into account. Dutch healthcare is responsible for 7% of the entire CO2 footprint, 4% of all waste and 13% of raw material consumption. In addition to the fact that making buildings and processes in healthcare more sustainable is desperately needed, we advocate that we also look at the care provided. We propose two approaches: firstly, not delivering the care that has no added value for the patient is the most sustainable care. So that needs to be looked at even more critically. Secondly, the effect on climate and the environment must be taken into account when choices are made between different care options. The social discussion should be conducted about how negative effects on the sustainability of the planet relate to (small) positive effects on individual health. How do quality, affordability and accessibility relate to sustainability? Given the urgency of the climate crisis, these questions need to be addressed now.

Using Existing Clinical Information Models for Dutch Quality Registries to Reuse Data and Follow COUMT Paradigm.

BACKGROUND: Reuse of health care data for various purposes, such as the care process, for quality measurement, research, and finance, will become increasingly important in the future; therefore, "Collect Once Use Many Times" (COUMT). Clinical information models (CIMs) can be used for content standardization. Data collection for national quality registries (NQRs) often requires manual data entry or batch processing. Preferably, NQRs collect required data by extracting data recorded during the health care process and stored in the electronic health record. OBJECTIVES: The first objective of this study was to analyze the level of coverage of data elements in NQRs with developed Dutch CIMs (DCIMs). The second objective was to analyze the most predominant DCIMs, both in terms of the coverage of data elements as well as in their prevalence across existing NQRs. METHODS: For the first objective, a mapping method was used which consisted of six steps, ranging from a description of the clinical pathway to a detailed mapping of data elements. For the second objective, the total number of data elements that matched with a specific DCIM was counted and divided by the total number of evaluated data elements. RESULTS: An average of 83.0% (standard deviation: 11.8%) of data elements in studied NQRs could be mapped to existing DCIMs . In total, 5 out of 100 DCIMs were needed to map 48.6% of the data elements. CONCLUSION: This study substantiates the potential of using existing DCIMs for data collection in Dutch NQRs and gives direction to further implementation of DCIMs. The developed method is applicable to other domains. For NQRs, implementation should start with the five DCIMs that are most prevalently used in the NQRs. Furthermore, a national agreement on the leading principle of COUMT for the use and implementation for DCIMs and (inter)national code lists is needed.

The risk of hypogonadism after testicular sperm extraction in men with various types of azoospermia: a prospective cohort study.

RESEARCH QUESTION: What is the risk of hypogonadism in men with obstructive azoospermia, non-obstructive azoospermia (NOA) or Klinefelter syndrome after testicular sperm extraction (TESE)? DESIGN: This prospective longitudinal cohort study was carried out between 2007 and 2015. RESULTS: Around 36% of men with Klinefelter syndrome, 4% of men with obstructive azoospermia and 3% of men with NOA needed testosterone replacement therapy (TRT). Klinefelter syndrome was strongly associated with TRT while no association was found between obstructive azoospermia or NOA and TRT. Irrespective of the pre-operative diagnosis, a higher testosterone concentration before TESE was associated with a lower chance of needing TRT. CONCLUSIONS: Men with obstructive azoospermia or NOA have a similar moderate risk of clinical hypogonadism after TESE, while this risk is much larger for men with Klinefelter syndrome. The risk of clinical hypogonadism is lower when testosterone concentrations are high before TESE.

Childhood cancer and hematological disorders negatively affect spermatogonial quantity at diagnosis: a retrospective study of a male fertility preservation cohort.

STUDY QUESTION: What is the impact of cancer or hematological disorders on germ cells in pediatric male patients? SUMMARY ANSWER: Spermatogonial quantity is reduced in testes of prepubertal boys diagnosed with cancer or severe hematological disorder compared to healthy controls and this reduction is disease and age dependent: patients with central nervous system cancer (CNS tumors) and hematological disorders, as well as boys <7 years are the most affected. WHAT IS KNOWN ALREADY: Fertility preservation in pediatric male patients is considered based on the gonadotoxicity of selected treatments. Although treatment effects on germ cells have been extensively investigated, limited data are available on the effect of the disease on the prepubertal male gonad. Of the few studies investigating the effects of cancer or hematologic disorders on testicular function and germ cell quantity in prepuberty, the results are inconsistent. However, recent studies suggested impairments before the initiation of known gonadotoxic therapy. Understanding which diseases and at what age affect the germ cell pool in pediatric patients before treatment is critical to optimize strategies and counseling for fertility preservation. STUDY DESIGN, SIZE, DURATION: This multicenter retrospective cohort study included 101 boys aged <14 years with extra-cerebral cancer (solid tumors), CNS tumors, leukemia/lymphoma (blood cancer), or non-malignant hematological disorders, who were admitted for a fertility preservation programme between 2002 and 2018. PARTICIPANTS/MATERIALS, SETTING, METHODS: In addition to clinical data, we analyzed measurements of testicular volume and performed histological staining on testicular biopsies obtained before treatment, at cryopreservation, to evaluate number of spermatogonia per tubular cross-section, tubular fertility index, and the most advanced germ cell type prior to chemo-/radiotherapy. The controls were data simulations with summary statistics from original studies reporting healthy prepubertal boys' testes characteristics. MAIN RESULTS AND THE ROLE OF CHANCE: Prepubertal patients with childhood cancer or hematological disorders were more likely to have significantly reduced spermatogonial quantity compared to healthy controls (48.5% versus 31.0% prevalence, respectively). The prevalence of patients with reduced spermatogonial quantity was highest in the CNS tumor (56.7%) and the hematological disorder (55.6%) groups, including patients with hydroxyurea pre-treated sickle cell disease (58.3%) and patients not exposed to hydroxyurea (50%). Disease also adversely impacted spermatogonial distribution and differentiation. Irrespective of disease, we observed the highest spermatogonial quantity reduction in patients <7 years of age. LIMITATIONS, REASONS FOR CAUTION: For ethical reasons, we could not collect spermatogonial quantity data in healthy prepubertal boys as controls and thus deployed statistical simulation on data from literature. Also, our results should be interpreted considering low patient numbers per (sub)group. WIDER IMPLICATIONS OF THE FINDINGS: Cancers, especially CNS tumors, and severe hematological disorders can affect spermatogonial quantity in prepubertal boys before treatment. Consequently, these patients may have a higher risk of depleted spermatogonia following therapies, resulting in persistent infertility. Therefore, patient counseling prior to disease treatment and timing of fertility preservation should not only be based on treatment regimes, but also on diagnoses and age. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by Marie Curie Initial Training Network (ITN) (EU-FP7-PEOPLE-2013-ITN) funded by European Commision grant no. 603568; ZonMW Translational Adult stem cell research (TAS) grant no. 116003002. No competing interests. TRIAL REGISTRATION NUMBER: N/A.

Statistical robustness of randomized controlled trials in high-impact journals has improved but was low across medical specialties.

OBJECTIVES: To determine whether the statistical fragility of randomized controlled trials (RCTs) in high-impact journals has improved in the last decade and to perform an umbrella review of all published data on the Fragility Index (FI) across medical specialties. STUDY DESIGN AND SETTING: The FI was calculated for all eligible RCTs published from 2014-2021 in the New England Journal of Medicine, The Lancet, the Journal of the American Medical Association, the British Medical Journal, and the Annals of Internal Medicine. Trials reporting dichotomous, statistically significant, superiority results were eligible. All previously published systematic reviews on the FI were included in the umbrella review and analyzed by medical (sub) specialty. RESULTS: Of 2,544 screened RCTs, 643 were eligible for the FI analysis. These had a median sample size of 625 (interquartile range [IQR]: 265-2,056), a median FI of 12 (IQR: 3-28), and a median Fragility Quotient of 0.015 (IQR: 0.004-0.045). This is an improvement compared with the median FI of 8 (IQR: 3-18) of RCTs published a decade earlier in the same five journals (P < 0.001). The umbrella review included 57 publications across 15 different medical specialties, with a total of between 10 and 692 RCTs for each specialty. The median FI ranged between two and four for all disciplines. CONCLUSION: In the last decade, the median statistical robustness of RCTs published in high-impact journals has improved, yet the unchanged lower bound of the interquartile range reveals that statistical significance in 25% of trials is still dependent on three or less events. The umbrella review revealed that statistical fragility is prevalent across all medical specialties. The FI is an easy-to-understand metric that can be used to supplement reported P values and help readers look beyond merely reaching statistical significance.

High incidence of outcome switching observed in follow-up publications of randomized controlled trials: Meta-research study.

OBJECTIVES: To determine the incidence of outcome switching in follow-up publications of randomized controlled trials. Outcome switching leads to bias where treatment benefits are more likely to be overestimated or based on chance. STUDY DESIGN AND SETTING: Meta-research study including all follow-up publications 2014-2018 in the New England Journal of Medicine, The Lancet, the Journal of the American Medical Association, and the British Medical Journal. Two independent reviewers compared the primary outcomes of follow-up publications with the original RCT publication and the trial protocol. RESULTS: Seventy-eight follow-up publications were identified. Thirty-one (40%) used different primary outcomes in the follow-up publication compared with the original RCT. In seventeen (55%) of these the outcome switch was neither pre-specified nor explained in the journal publication. The incidence of outcome switching in follow-up studies rose to 70% when preceded by outcome switching in the corresponding initial RCT (P< 0.001). CONCLUSION: In this study, outcome switching occurred in 40% of follow-up publications of previously published RCTs. The majority is neither pre-specified nor explained.

IGSF1 Does Not Regulate Spermatogenesis or Modify FSH Synthesis in Response to Inhibins or Activins.

Loss-of-function mutations in the X-linked immunoglobulin superfamily, member 1 (IGSF1) gene result in central hypothyroidism, often associated with macroorchidism. Testicular enlargement in these patients might be caused by increases in follicle-stimulating hormone (FSH) levels, as IGSF1 has been proposed to function as an inhibin B receptor or as an inhibitor of activin type I receptor (ALK4) activity in pituitary gonadotrope cells. If true, loss of IGSF1 should lead to reduced inhibin B action or disinhibition of activin signaling, thereby increasing FSH synthesis. Here, we show that FSH levels and sperm counts are normal in male Igsf1 knockout mice, although testis size is mildly increased. Sperm parameters are also normal in men with IGSF1 deficiency, although their FSH levels may trend higher and their testes are enlarged. Inhibin B retains the ability to suppress FSH synthesis in pituitaries of Igsf1-knockout mice and IGSF1 does not interact with ALK4 or alter activin A/ALK4 stimulation of FSHß (Fshb/FSHB) subunit transcription or expression. In light of these results, it is unlikely that macroorchidism in IGSF1 deficiency derives from alterations in spermatogenesis or inhibin/activin regulation of FSH.

ITGA6+ Human Testicular Cell Populations Acquire a Mesenchymal Rather than Germ Cell Transcriptional Signature during Long-Term Culture.

Autologous spermatogonial stem cell transplantation is an experimental technique aimed at restoring fertility in infertile men. Although effective in animal models, in vitro propagation of human spermatogonia prior to transplantation has proven to be difficult. A major limiting factor is endogenous somatic testicular cell overgrowth during long-term culture. This makes the culture both inefficient and necessitates highly specific cell sorting strategies in order to enrich cultured germ cell fractions prior to transplantation. Here, we employed RNA-Seq to determine cell type composition in sorted integrin alpha-6 (ITGA6+) primary human testicular cells (n = 4 donors) cultured for up to two months, using differential gene expression and cell deconvolution analyses. Our data and analyses reveal that long-term cultured ITGA6+ testicular cells are composed mainly of cells expressing markers of peritubular myoid cells, (progenitor) Leydig cells, fibroblasts and mesenchymal stromal cells and only a limited percentage of spermatogonial cells as compared to their uncultured counterparts. These findings provide valuable insights into the cell type composition of cultured human ITGA6+ testicular cells during in vitro propagation and may serve as a basis for optimizing future cell sorting strategies as well as optimizing the current human testicular cell culture system for clinical use.

High-quality human preimplantation embryos stimulate endometrial stromal cell migration via secretion of microRNA hsa-miR-320a.

STUDY QUESTION: How do high-quality human preimplantation embryos influence the endometrium to promote their own implantation? SUMMARY ANSWER: High-quality human preimplantation embryos secrete a specific microRNA (miRNA), hsa-miR-320a, which promotes migration of human endometrial stromal cells (hESCs). WHAT IS KNOWN ALREADY: We have previously shown that high-quality human preimplantation embryos excrete unknown factors that influence migration of hESCs. STUDY DESIGN, SIZE, DURATION: Embryo excreted miRNAs, specifically those excreted by high-quality embryos, were identified and their effect on hESCs was determined by measuring the migration capacity and gene expression patterns of primary isolated hESCs. PARTICIPANTS/MATERIALS, SETTING, METHODS: Embryo conditioned medium (ECM) from routine ICSI procedures was used to identify embryo excreted miRNAs. miRNome analyses were performed on ECM from individually cultured embryos with high morphological quality, with low morphological quality or empty control medium. MiRNA mimics and inhibitors were then used to further study the effect of miRNAs of interest on migration and gene expression of hESCs. Migration assays were performed using hESCs that were obtained from endometrial biopsies performed on hysterectomy specimens from women that received surgery for spotting due to a niche in a cesarean section scar. MAIN RESULTS AND THE ROLE OF CHANCE: By using miRNA mimics and inhibitors, we showed that hsa-miR-320a alone can stimulate migration of decidualized hESCs, accurately resembling the response typically triggered only by high-quality embryos. Transcriptome analysis further demonstrated that this effect is very likely mediated via altered expression of genes involved in cell adhesion and cytoskeleton organization. LIMITATIONS, REASONS FOR CAUTION: The effect of hsa-miR-320a on hESCs was measured in vitro. Further studies on the in vivo effect of hsa-miR-320a are warranted. WIDER IMPLICATIONS OF THE FINDINGS: Implantation failure is one of the major success limiting factors in human reproduction. By secreting hsa-miR-320a, high-quality human preimplantation embryos directly influence hESCs, most likely to prime the endometrium at the implantation site for successful implantation. Together, our results indicate that hsa-miR-320a may be a promising target to further increase success rates in assisted reproduction. STUDY FUNDING/COMPETING INTEREST(S): The study was funded by the Amsterdam University Medical Centers and the Amsterdam Reproduction & Development Research Institute. R.P.B., G.H. and S.M. have a patent on the use of hsa-miR-320a in assisted reproduction treatments pending. TRIAL REGISTRATION NUMBER: N/A.

A comparative analysis of human adult testicular cells expressing stem Leydig cell markers in the interstitium, vasculature, and peritubular layer.

BACKGROUND: Origin of human adult Leydig cells (ALCs) is not well understood. This might be partly due to limited data available on the identification and location of human precursor and stem Leydig cells (SLCs) which hampers the study on the development of ALCs. OBJECTIVES: The aim of the present study was to investigate whether described human (PDGFRα, NGFR) and rodent (NES, PDGFRα, THY1, NR2F2) SLC markers are expressed by a common cell population within human adult testicular interstitial cells in vivo and before and after in vitro propagation. MATERIALS AND METHODS: Immunohistochemical analyses were used to identify localization of human adult testicular interstitial cells expressing described SLC markers. Next, interstitial cells were isolated and cultured. The percentage of cells expressing one or more SLC markers was determined before and after culture using flow cytometry. RESULTS: NR2F2 and PDGFRα were present in peritubular, perivascular, and Leydig cells, while THY1 was expressed in peritubular and perivascular cells. Although NES and NGFR were expressed in endothelial cells, co-localization with PDGFRα was found for both in vitro, although for NGFR only after culture. All marker positive cells were able to undergo propagation in vitro. DISCUSSION: The partly overlap in localization and overlap in expression in human testicular cells indicate that PDGFRα, NR2F2, and THY1 are expressed within the same ALC developmental lineage from SLCs. Based on the in vitro results, this is also true for NES and after in vitro propagation for NGFR. CONCLUSION: Our results that earlier described SLC markers are expressed in overlapping human interstitial cell population opens up further research strategies aiming for a better insight in the Leydig cell lineage and will be helpful for development of strategies to cure ALC dysfunction.

Comparing genome-scale DNA methylation and CNV marks between adult human cultured ITGA6+ testicular cells and seminomas to assess in vitro genomic stability.

Autologous transplantation of spermatogonial stem cells is a promising new avenue to restore fertility in infertile recipients. Expansion of the initial spermatogonial stem cell pool through cell culturing is a necessary step to obtain enough cells for effective repopulation of the testis after transplantation. Since in vitro propagation can lead to (epi-)genetic mutations and possibly malignant transformation of the starting cell population, we set out to investigate genome-wide DNA methylation status in uncultured and cultured primary testicular ITGA6+ sorted cells and compare them with germ cell tumor samples of the seminoma subtype. Seminomas displayed a severely global hypomethylated profile, including loss of genomic imprinting, which we did not detect in cultured primary testicular ITGA6+ cells. Differential methylation analysis revealed altered regulation of gamete formation and meiotic processes in cultured primary testicular ITGA6+ cells but not in seminomas. The pivotal POU5F1 marker was hypomethylated in seminomas but not in uncultured or cultured primary testicular ITGA6+ cells, which is reflected in the POU5F1 mRNA expression levels. Lastly, seminomas displayed a number of characteristic copy number variations that were not detectable in primary testicular ITGA6+ cells, either before or after culture. Together, the data show a distinct DNA methylation patterns in cultured primary testicular ITGA6+ cells that does not resemble the pattern found in seminomas, but also highlight the need for more sensitive methods to fully exclude the presence of malignant cells after culture and to further study the epigenetic events that take place during in vitro culture.

Comparison of DNA methylation patterns of parentally imprinted genes in placenta derived from IVF conceptions in two different culture media.

STUDY QUESTION: Is there a difference in DNA methylation status of imprinted genes in placentas derived from IVF conceptions where embryo culture was performed in human tubal fluid (HTF) versus G5 culture medium? SUMMARY ANSWER: We found no statistically significant differences in the mean DNA methylation status of differentially methylated regions (DMRs) associated with parentally imprinted genes in placentas derived from IVF conceptions cultured in HTF versus G5 culture medium. WHAT IS KNOWN ALREADY: Animal studies indicate that the embryo culture environment affects the DNA methylation status of the embryo. In humans, birthweight is known to be affected by the type of embryo culture medium used. The effect of embryo culture media on pregnancy, birth and child development may thus be mediated by differential methylation of parentally imprinted genes in the placenta. STUDY DESIGN, SIZE, DURATION: To identify differential DNA methylation of imprinted genes in human placenta derived from IVF conceptions exposed to HTF or G5 embryo culture medium, placenta samples (n = 43 for HTF, n = 54 for G5) were collected between 2010 and 2012 s as part of a multi-center randomized controlled trial in the Netherlands comparing these embryo culture media. Placenta samples from 69 naturally conceived (NC) live births were collected during 2008-2013 in the Netherlands as reference material. PARTICIPANTS/MATERIALS, SETTING, METHODS: To identify differential DNA methylation of imprinted genes, we opted for an amplicon-based sequencing strategy on an Illumina MiSeq sequencing platform. DNA was isolated and 34 DMRs associated with well-defined parentally imprinted genes were amplified in a two-step PCR before sequencing using MiSeq technology. Sequencing data were analyzed in a multivariate fashion to eliminate possible confounding effects. MAIN RESULTS AND THE ROLE OF CHANCE: We found no statistically significant differences in the mean DNA methylation status of any of the imprinted DMRs in placentas derived from IVF conceptions cultured in HTF or G5 culture medium. We also did not observe any differences in the mean methylation status per amplicon nor in the variance in methylation per amplicon between the two culture medium.groups. A separate surrogate variable analysis also demonstrated that the IVF culture medium was not associated with the DNA methylation status of these DMRs. The mean methylation level and variance per CpG was equal between HTF and G5 placenta. Additional comparison of DNA methylation status of NC placenta samples revealed no statistically significant differences in mean amplicon and CpG methylation between G5, HTF and NC placenta; however, the number of placenta samples exhibiting outlier methylation levels was higher in IVF placenta compared to NC (P < 0.00001). Also, we were able to identify 37 CpG sites that uniquely displayed outlier methylation in G5 placentas and 32 CpG sites that uniquely displayed outlier methylation in HTF. In 8/37 (G5) and 4/32 (HTF) unique outliers CpGs, a medium-specific unique outlier could be directly correlated to outlier methylation of the entire amplicon. LIMITATIONS, REASONS FOR CAUTION: Due to practical reasons, not all placentas were collected during the trial, and we collected the placentas from natural conceptions from a different cohort, potentially creating bias. We limited ourselves to the DNA methylation status of 34 imprinted DMRs, and we studied only the placenta and no other embryo-derived tissues. WIDER IMPLICATIONS OF THE FINDINGS: It has often been postulated, but has yet to be rigorously tested, that imprinting mediates the effects of embryo culture conditions on pregnancy, birth and child development in humans. Since we did not detect any statistically significant effects of embryo culture conditions on methylation status of imprinted genes in the placenta, this suggests that other unexplored mechanisms may underlie these effects. The biological and clinical relevance of detected outliers with respect to methylation levels of CpGs and DMR require additional analysis in a larger sample size as well. Given the importance and the growing number of children born through IVF, research into these molecular mechanisms is urgently needed. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the March of Dimes grant number #6-FY13-153. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER: Placental biopsies were obtained under Netherlands Trial Registry number 1979 and 1298.