Hamster DAX1: Molecular insights, specific expression, and its role in the Harderian gland

DAX1 plays an essential role in the differentiation and physiology of the Hypothalamic-Pituitary-Adrenal-Gonadal (HPAG) axis during embryogenesis. However, in adult tissues, in addition to the HPAG axis, evidence has not been found for its differential expression and function. We isolated the DAX1 cDNA to analyze its tissue localization and gene expression profiles in male and female hamsters' Harderian glands (HGs), Mesocricetus auratus. The isolated cDNA clone contains 1848 base pairs (bp), and a 1428-bp open reading frame (ORF) encodes a 476 amino acid protein. Sequence alignments and the phylogenetic tree display a relevant percentage of similarity with human (66%), rat (81%), and mouse (84%) sequences. In adult tissues, the mRNA distribution demonstrated that DAX1 is present in testis, ovaries, and male and female HGs. The highest expression profiles were identified in the adrenal glands, where females exhibit higher mRNA levels than males. The sexually dimorphic expression of DAX1 in adrenals suggests that its presence could be associated with regulating, functioning, and maintaining this endocrine tissue. These findings indicate that the DAX1 gene is limitedly expressed in adult tissues. In the HGs, we demonstrate the absence of sexually dimorphic gene expression. Our results suggest that DAX1 might have an additional physiological function outside of the HPAG axis, specifically in the HG, which may be required for the regulation of intracrine steroidogenesis, secretion, and maintenance of exocrine tissue.

Exome sequencing reveals variants in known and novel candidate genes for severe sperm motility disorders

STUDY QUESTION

What are the causative genetic variants in patients with male infertility due to severe sperm motility disorders?

SUMMARY ANSWER

We identified high confidence disease-causing variants in multiple genes previously associated with severe sperm motility disorders in 10 out of 21 patients (48%) and variants in novel candidate genes in seven additional patients (33%).

WHAT IS KNOWN ALREADY

Severe sperm motility disorders are a form of male infertility characterised by immotile sperm often in combination with a spectrum of structural abnormalities of the sperm flagellum that do not affect viability. Currently, depending on the clinical sub-categorisation, up to 50% of causality in patients with severe sperm motility disorders can be explained by pathogenic variants in at least 22 genes.

STUDY DESIGN, SIZE, DURATION

We performed exome sequencing in 21 patients with severe sperm motility disorders from two different clinics.

PARTICIPANTS/MATERIALS, SETTING, METHOD

Two groups of infertile men, one from Argentina (n = 9) and one from Australia (n = 12), with clinically defined severe sperm motility disorders (motility <5%) and normal morphology values of 0-4%, were included. All patients in the Argentine cohort were diagnosed with DFS-MMAF, based on light and transmission electron microscopy. Sperm ultrastructural information was not available for the Australian cohort. Exome sequencing was performed in all 21 patients and variants with an allele frequency of <1% in the gnomAD population were prioritised and interpreted.

MAIN RESULTS AND ROLE OF CHANCE

In 10 of 21 patients (48%), we identified pathogenic variants in known sperm assembly genes: CFAP43 (3 patients); CFAP44 (2 patients), CFAP58 (1 patient), QRICH2 (2 patients), DNAH1 (1 patient) and DNAH6 (1 patient). The diagnostic rate did not differ markedly between the Argentinian and the Australian cohort (55% and 42%, respectively). Furthermore, we identified patients with variants in the novel human candidate sperm motility genes: DNAH12, DRC1, MDC1, PACRG, SSPL2C and TPTE2. One patient presented with variants in four candidate genes and it remains unclear which variants were responsible for the severe sperm motility defect in this patient.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

In this study, we described patients with either a homozygous or two heterozygous candidate pathogenic variants in genes linked to sperm motility disorders. Due to unavailability of parental DNA, we have not assessed the frequency of de novo or maternally inherited dominant variants and could not determine the parental origin of the mutations to establish in all cases that the mutations are present on both alleles.

WIDER IMPLICATIONS OF THE FINDINGS

Our results confirm the likely causal role of variants in six known genes for sperm motility and we demonstrate that exome sequencing is an effective method to diagnose patients with severe sperm motility disorders (10/21 diagnosed; 48%). Furthermore, our analysis revealed six novel candidate genes for severe sperm motility disorders. Genome-wide sequencing of additional patient cohorts and re-analysis of exome data of currently unsolved cases may reveal additional variants in these novel candidate genes.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported in part by funding from the Australian National Health and Medical Research Council (APP1120356) to M.K.O.B., J.A.V. and R.I.M.L., The Netherlands Organisation for Scientific Research (918-15-667) to J.A.V., the Royal Society and Wolfson Foundation (WM160091) to J.A.V., as well as an Investigator Award in Science from the Wellcome Trust (209451) to J.A.V. and Grants from the National Research Council of Argentina (PIP 0900 and 4584) and ANPCyT (PICT 9591) to H.E.C. and a UUKi Rutherford Fund Fellowship awarded to B.J.H.

Detailed Morphological Analysis of Cryoinjury in Human Ovarian Tissue Following Vitrification or Slow Freezing

Cryopreservation of human ovarian tissue represents a key procedure for fertility preservation. The two most widely used cryopreservation methods for human ovarian cortex samples are slow freezing\thawing (SF\T) and vitrification\warming (V\W). The aim of the present study was to analyze the effects of SF\T and V\W using a metal chamber, on specific follicle and oocyte structures and on the stromal organization post-cryopreservation. We did histology analysis of SF\T and V\W ovarian fragments from nine healthy subjects. Overall results showed that cryopreserved tissues presented significant rates of damage in primordial and primary follicles. Altered nuclear structure of primordial follicles and cell detachment from primordial and primary follicles were the main injuries observed after V/W and SF/T. The stromal components were similarly well preserved after cryopreservation. We conclude that both cryopreservation methods may be used for fertility preservation purposes with similar outcomes in terms of follicular and stromal integrity. Detachment of follicle cells from basal membrane represents an important cryoinjury that deserves further investigation.

va. d. Werken C, Ramos L. P–133 Monopronuclear (1PN) embryos can derive in healthy pregnancies

Study question

Should 1PN embryos be considered suitable for transfer when normal development is observed at day 3 or day 5?

Summary answer

In IVF/ICSI cycles, 1PN zygotes are encountered in 2.7% of inseminated oocytes. Transfer of 1PN-embryos should be considered in the absence of suitable 2PN embryos.

What is known already

During in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) zygotes containing only a single pronucleus (monopronuclear, 1PN) are encountered in 1–7.7% of cases, while the display of two pronuclei is expected in a normally fertilised oocyte. A 1PN zygote can be of gynogenetic or androgenetic origin, but it can also be biparental. Gynogenetic and androgenetic 1PN embryos can be haploid or diploid, so a diploid 1PN embryo is not guaranteed to be normally fertilised. Generally, 1PN are discarded, as they have an increased risk for aneuploidy. However, sporadically they can develop into healthyl babies.

Study design, size, duration

1PN-zygotes (n = 1287, 2.7% from all inseminated oocytes) from 1–1–2016 up to 15–12–2020 were retrospectively evaluated. The development and fate (discarded/transferred/cryopreserved) of all embryos were recorded. Embryos were evaluated at day 2, 3 or 5 of development. The policy of our unit is that, in absence of 2PN embryos, normal developed 1PN-embryos can be transferred on day 3. Supernumerary 1PN embryos can be cryopreserved at blastocyst stage. Ongoing pregnancies from fresh embryo transfers (ET) were analysed.

Participants/materials, setting, methods

In 946 IVF/ICSI cycles, at least one 1PN zygote was observed (total 1287 embryos). ICSI with ejaculated, PESA or TESE sperm counted for a total of 795 embryos, IVF cycles for 494 embryos. Embryo evaluation was performed using a home-made numerical algorithm: A (top embryo; 150–200 points), B (regular embryo; 100–149 points) or C (poor embryo; 0–99 points). Monopronuclear embryos always scored lower than equal developed 2PN embryos. Blastocyst evaluation was according to Gardner score.

Main results and the role of chance

From the 795 ICSI embryos, 49 (6.1%) were used for fresh ET (26 scored quality A or B), and a total of 60 embryos developed to blastocyst and were cryopreserved. From these 49 ICSI transfers, 4 (8.1%) ongoing pregnancies were obtained, all 4 from DET (1PN+2PN embryo), from which one twin pregnancy was confirmed. From the 494 IVF embryos, 41 (8.3%) were used for fresh ET (24 scored A or B), and 62 blastocysts were cryopreserved. A total of 9/41 (22%) ongoing pregnancies were obtained: 5 from SET (1PN) and 4 from DET (1PN+ 2PN embryo). Therefore, in only five IVF cycles a confirmed pregnancy was observed from a 1PN embryo (all A-quality embryos).

Considering six ongoing pregnancies with complete certainty of monopronuclear origin from fresh tranfers could be confirmed from our retrospective data, we can conclude that although the live birth rate of these embryos is very low (around 0,5- 1.0%), they should not be discarded when development is normal and no dipronuclear embryos are present.

Limitations, reasons for caution

Cryo-thawing data is missing as these embryos were not differentially marked at freezing. Therefore, the cumulative pregnancies from monopronuclear embryos could be higher. Embryos were not evaluated in a time lapse system, so asynchronicity of PN formation could explain missing the right moment for evaluation, while normal fertilized.

Wider implications of the findings: Notably, IVF monopronuclear embryos display a higher developmental potential than those derived from ICSI. We suggest that, in absence of dipronuclear embryos, culture to blastocyst stage before considering fresh ET or cryopreservation will help differentiate viable 1PN embryos, reducing the higher chance of genetic anomalies and miscarriages.

Trial registration number

N.A.

Exhaustive characterization of (semi-)volatile organic contaminants in car dust using comprehensive two-dimensional gas chromatography ‒ Time-of-flight mass spectrometry

This work represents the first reported effort to build an extensive database of the organic volatile and semi-volatile contaminants present in car dust as a result of migration from materials used in auto-manufacturing. Untargeted analysis of car dust samples has been performed using comprehensive two-dimensional gas chromatography combined with time-of-fight mass spectrometry (GC×GC ‒ToF MS) after generic sample preparation. The enhanced separation power and structural confirmation capabilities provided by this technique have been used for the either positive or tentative identification of 245 GC-amenable compounds, a number of them being identified for the first time in this type of matrix. Information concerning 5 compounds remaining unidentified has also been provided. Results have been summarised in a searchable database containing chromatographic, mass spectral and normalised abundances calculated for the detected analytes in the ten investigated car dusts used to discuss the main findings of the study. Results are expected to serve other researcher to take decisions concerning priority analytes for further evaluation in this research field and for car manufacturers who might search for safer materials.

Harderian SOX9: Molecular characterization and its dimorphic expression in hamster

The molecular action of SOX9 can promote lipogenesis. Because the hamster Harderian gland (HG) synthesizes lipids and exhibits sexual dimorphism, this study aimed to identify and characterize Harderian SOX9. We examined the tissue distribution and expression profiles of SOX9 in hamster Mesocricetus auratus HGs. The full-length SOX9 cDNA sequence [3649-base pairs (bp)] contains an 81-bp 5' untranslated region (UTR), a 3' UTR of 2044-bp, an open reading frame (ORF) of 1524-bp, and a polyadenylation signal (AATAAA) at 19-bp upstream of poly(A) tail. The cDNA encodes a 507 amino acid protein containing the potential DNA-binding domain known as the HMG box. BLAST analysis revealed 99%, 99%, and 97% identity with the SOX9 of mouse, rat, and human, respectively. High expression levels were also observed in the testis, cerebellum, and hypothalamus. qPCR analysis demonstrated that SOX9 is expressed more abundantly in the HGs of males than in females. Sexually dimorphic expression of SOX9 suggests that differential expression between male and female HGs could be under the regulation of sex steroids. SOX9 might play a similar role in regulating exocrine secretions of lipids; these could occur downstream of FGF signaling - as found during embryogenesis - and/or androgen signaling.

Effect of parental and ART treatment characteristics on perinatal outcomes

STUDY QUESTION

Do parental characteristics and treatment with ART affect perinatal outcomes in singleton pregnancies?

SUMMARY ANSWER

Both parental and ART treatment characteristics affect perinatal outcomes in singleton pregnancies.

WHAT IS KNOWN ALREADY

Previous studies have shown that singleton pregnancies resulting from ART are at risk of preterm birth. ART children are lighter at birth after correction for duration of gestation and at increased risk of congenital abnormalities compared to naturally conceived children. This association is confounded by parental characteristics that are also known to affect perinatal outcomes. It is unclear to which extent parental and ART treatment characteristics independently affect perinatal outcomes.

STUDY DESIGN, SIZE, DURATION

All IVF clinics in the Netherlands (n = 13) were requested to provide data on all ART treatment cycles (IVF, ICSI and frozen-thawed embryo transfers (FET)), performed between 1 January 2000, and 1 January 2011, which resulted in a pregnancy. Using probabilistic data-linkage, these data (n = 36 683) were linked to the Dutch Perinatal Registry (Perined), which includes all children born in the Netherlands in the same time period (n = 2 548 977).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Analyses were limited to singleton pregnancies that resulted from IVF, ICSI or FET cycles. Multivariable models for linear and logistic regression were fitted including parental characteristics as well as ART treatment characteristics. Analyses were performed separately for fresh cycles and for fresh and FET cycles combined. We assessed the impact on the following perinatal outcomes: birth weight, preterm birth below 37 or 32 weeks of gestation, congenital malformations and perinatal mortality.

MAIN RESULTS AND THE ROLE OF CHANCE

The perinatal outcomes of 31 184 out of the 36 683 ART treatment cycles leading to a pregnancy were retrieved through linkage with the Perined (85% linkage). Of those, 23 671 concerned singleton pregnancies resulting from IVF, ICSI or FET. Birth weight was independently associated with both parental and ART treatment characteristics. Characteristics associated with lower birth weight included maternal hypertensive disease, non-Dutch maternal ethnicity, nulliparity, increasing duration of subfertility, hCG for luteal phase support (compared to progesterone), shorter embryo culture duration, increasing number of oocytes retrieved and fresh embryo transfer. The parental characteristic with the greatest effect size on birth weight was maternal diabetes (adjusted difference 283 g, 95% CI 228-338). FET was the ART treatment characteristic with the greatest effect size on birth weight (adjusted difference 100 g, 95% CI 84-117) compared to fresh embryo transfer. Preterm birth was more common among mothers of South-Asian ethnicity. Preterm birth was less common among multiparous women and women with 'male factor' as treatment indication (compared to 'tubal factor').

LIMITATIONS, REASONS FOR CAUTION

Due to the retrospective nature of our study, we cannot prove causality. Further limitations of our study were the inability to adjust for mothers giving birth more than once in our dataset, missing values for several variables and limited information on parental lifestyle and general health.

WIDER IMPLICATIONS OF THE FINDINGS

Multiple parental and ART treatment characteristics affect perinatal outcomes, with birth weight being influenced by the widest range of factors. This highlights the importance of assessing both parental and ART treatment characteristics in studies that focus on the health of ART-offspring, with the purpose of modifying these factors where possible. Our results further support the hypothesis that the embryo is sensitive to its early environment.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Foreest Medical School, Alkmaar, the Netherlands (grants: FIO 1307 and FIO 1505). B.W.M. reports grants from NHMRC and consultancy for ObsEva, Merck KGaA, iGenomics and Guerbet. F.B. reports research support grants from Merck Serono and personal fees from Merck Serono. A.C. reports travel support from Ferring BV. and Theramex BV. and personal fees from UpToDate (Hyperthecosis), all outside the remit of the current work. The remaining authors report no conflict of interests.

TRIAL REGISTRATION NUMBER

N/A.

Exome sequencing reveals novel causes as well as new candidate genes for human globozoospermia

STUDY QUESTION

Can exome sequencing identify new genetic causes of globozoospermia?

SUMMARY ANSWER

Exome sequencing in 15 cases of unexplained globozoospermia revealed deleterious mutations in seven new genes, of which two have been validated as causing globozoospermia when knocked out in mouse models.

WHAT IS KNOWN ALREADY

Globozoospermia is a rare form of male infertility characterised by round-headed sperm and malformation of the acrosome. Although pathogenic variants in DPY19L2 and SPATA16 are known causes of globozoospermia and explain up to 70% of all cases, genetic causality remains unexplained in the remaining patients.

STUDY DESIGN, SIZE, DURATION

After pre-screening 16 men for mutations in known globozoospermia genes DPY19L2 and SPATA16, exome sequencing was performed in 15 males with globozoospermia or acrosomal hypoplasia of unknown aetiology.

PARTICIPANTS/MATERIALS, SETTING, METHOD

Targeted next-generation sequencing and Sanger sequencing was performed for all 16 patients to screen for single-nucleotide variants and copy number variations in DPY19L2 and SPATA16. After exclusion of one patient with DPY19L2 mutations, we performed exome sequencing for the 15 remaining subjects. We prioritised recessive and X-linked protein-altering variants with an allele frequency of <0.5% in the population database GnomAD in genes with an enhanced expression in the testis. All identified candidate variants were confirmed in patients and, where possible, in family members using Sanger sequencing. Ultrastructural examination of semen from one of the patients allowed for a precise phenotypic characterisation of abnormal spermatozoa.

MAIN RESULTS AND ROLE OF CHANCE

After prioritisation and validation, we identified possibly causative variants in eight of 15 patients investigated by exome sequencing. The analysis revealed homozygous nonsense mutations in ZPBP and CCDC62 in two unrelated patients, as well as rare missense mutations in C2CD6 (also known as ALS2CR11), CCIN, C7orf61 and DHNA17 and a frameshift mutation in GGN in six other patients. All variants identified through exome sequencing, except for the variants in DNAH17, were located in a region of homozygosity. Familial segregation of the nonsense variant in ZPBP revealed two fertile brothers and the patient’s mother to be heterozygous carriers. Paternal DNA was unavailable. Immunohistochemistry confirmed that ZPBP localises to the acrosome in human spermatozoa. Ultrastructural analysis of spermatozoa in the patient with the C7orf61 mutation revealed a mixture of round heads with no acrosomes (globozoospermia) and ovoid or irregular heads with small acrosomes frequently detached from the sperm head (acrosomal hypoplasia).

LIMITATIONS, REASONS FOR CAUTION

Stringent filtering criteria were used in the exome data analysis which could result in possible pathogenic variants remaining undetected. Additionally, functional follow-up is needed for several candidate genes to confirm the impact of these mutations on normal spermatogenesis.

WIDER IMPLICATIONS OF THE FINDINGS

Our study revealed an important role for mutations in ZPBP and CCDC62 in human globozoospermia as well as five new candidate genes. These findings provide a more comprehensive understanding of the genetics of male infertility and bring us closer to a complete molecular diagnosis for globozoospermia patients which would help to predict the success of reproductive treatments.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by The Netherlands Organisation for Scientific Research (918–15-667); National Health and Medical Research Council of Australia (APP1120356) and the National Council for Scientific Research (CONICET), Argentina, PIP grant 11220120100279CO. The authors have nothing to disclose.

Dutasteride combined with androgen receptor antagonists inhibit glioblastoma U87 cell metabolism, proliferation, and invasion capacity: Androgen regulation

Glioblastoma (GB) is the most common and aggressive primary brain tumor in adult humans. Therapeutic resistance and tumor recurrence after surgical resection contributes to a poor prognosis for glioblastoma patients. Men are known to be more likely than women to develop an aggressive form of GB. Although the reasons for this disparity remain poorly understood, differences in sex steroids have emerged as a leading explanation. Studies indicate that GB-derived cells express androgen receptors (ARs) and synthesize androgens, suggesting that androgens may have a role in the tumor pathogenesis. Thus, our objective was to investigate the effects of the 5α-reductase enzyme inhibitor dutasteride, the AR antagonists cyproterone and flutamide, and combinations of these drugs on the metabolism, proliferation, and invasion capacity of GB-derived U87 cells. We also examined the effects of three natural androgens testosterone, androstenedione and dihydrotestosterone (T, A₄, and DHT) on these cells. Cell metabolism was investigated by MTT assay, proliferation was assessed by the bromodeoxyuridine (BrdU) incorporation assay, and invasion was assessed by Boyden chamber assay. The results revealed that T and especially DHT, but not A₄, increased U87 cell metabolism and proliferation. Following these findings, we examined the effect of adding dutasteride, cyproterone, or flutamide to the culture media and found that they all significantly decreased cell metabolism and proliferation. Dutasteride also significantly reduced cell invasion. Moreover, any combination of these drugs enhanced their inhibitory effects; the combination of dutasteride to flutamide was most effective at decreasing GB cell proliferation. Our results suggest that administering a combination of AR antagonists and enzyme blockers may be a more effective alternative treatment for GB.

Molecular genetic analysis of AKR1C2-4 and HSD17B6 genes in subjects 46,XY with hypospadias

BACKGROUND

The formation of the male urethra depends to enzyme-mediated testosterone (T) conversion into 5α-dihydrotestosterone (DHT). Two metabolic pathways could be operating in the fetal testis to synthesize androgens: 1) the "classic" route (T→DHT) mediated by SRD5A2 and 2) a "backdoor" pathway in which DHT is synthesized by aldo-keto reductase family 1, member C2 (AKR1C2), AKR1C3, and AKR1C4 enzymes without formation of a T intermediate.

OBJECTIVE

We studied four genes of the "backdoor" pathway in karyotypic males with hypospadias to ascertain whether gene defects in AKRs impair urethral DHT formation that result in hypospadias.

DESIGN AND PATIENTS

The coding regions of the AKR1C2-4 and HSD17B6 genes were analyzed by PCR-SSCP and sequencing in a cohort of 25 Mexican patients (0.3-9 year-old-children) with 46,XY-hypospadias. Chi-squared tests was performed to evaluate the distribution of genotypes, alleles, and the Hardy-Weinberg (H-W) equilibrium. The effect of the genetic variants was investigated by in silico studies.

RESULTS

Screening studies revealed distinct genotypic patterns at different exons of AKR1C2-4 whereas HSD17B6 presented a wild-type sequence. The DNA analyses detected two synonymous variants (c.327C>T, c.666T>C/unreported) in AKR1C2. The AKR1C3 had two variants (c.15C>G, c.230A>G), two unreported variants (c.538T>C, c.596G>A), and one silent variant (c.312G>A). Two variants (c.434C>G, c.931C>G) were identified in AKR1C4. All variants were in H-W equilibrium without structural changes.

DISCUSSION

Hypospadias have been associated with defects that alter androgen biosynthesis in the human fetal testis, specifically 5α-DHT. We selected four candidate genes involved in the "backdoor" pathway for the formation of 5α-DHT. Molecular assays of the AKR1C2, AKR1C3, and AKR1C4 genes revealed a total of nine genetic single nucleotide variants. Several variants in the AKR1C genes have been associated with a variety of human pathologies. However, our studies suggest that active steroid biosynthesis via AKR1C might not be involved in hypospadias. Additionally, genetic research suggests a low involvement in the "backdoor" 5α-DHT pathway during human sexual development, specifically, the differentiation of male external genitalia.

CONCLUSION

These results indicate that substitutions in AKR1C2-4 are polymorphisms and all genetic variants lacks deleterious significant association with hypospadias. The data suggest that inactivating mutations in the AKR1C2-4 and HSD17B6 genes are an infrequent cause of hypospadias, which might weaken the contribution of the "backdoor" pathway to embryonic urethral masculinization.

Fertility preservation in boys: recent developments and new insights †

BACKGROUND

Infertility is an important side effect of treatments used for cancer and other non-malignant conditions in males. This may be due to the loss of spermatogonial stem cells (SSCs) and/or altered functionality of testicular somatic cells (e.g. Sertoli cells, Leydig cells). Whereas sperm cryopreservation is the first-line procedure to preserve fertility in post-pubertal males, this option does not exist for prepubertal boys. For patients unable to produce sperm and at high risk of losing their fertility, testicular tissue freezing is now proposed as an alternative experimental option to safeguard their fertility.

OBJECTIVE AND RATIONALE

With this review, we aim to provide an update on clinical practices and experimental methods, as well as to describe patient management inclusion strategies used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss.

SEARCH METHODS

Based on the expertise of the participating centres and a literature search of the progress in clinical practices, patient management strategies and experimental methods used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss were identified. In addition, a survey was conducted amongst European and North American centres/networks that have published papers on their testicular tissue banking activity.

OUTCOMES

Since the first publication on murine SSC transplantation in 1994, remarkable progress has been made towards clinical application: cryopreservation protocols for testicular tissue have been developed in animal models and are now offered to patients in clinics as a still experimental procedure. Transplantation methods have been adapted for human testis, and the efficiency and safety of the technique are being evaluated in mouse and primate models. However, important practical, medical and ethical issues must be resolved before fertility restoration can be applied in the clinic.Since the previous survey conducted in 2012, the implementation of testicular tissue cryopreservation as a means to preserve the fertility of prepubertal boys has increased. Data have been collected from 24 co-ordinating centres worldwide, which are actively offering testis tissue cryobanking to safeguard the future fertility of boys. More than 1033 young patients (age range 3 months to 18 years) have already undergone testicular tissue retrieval and storage for fertility preservation.

LIMITATIONS REASONS FOR CAUTION

The review does not include the data of all reproductive centres worldwide. Other centres might be offering testicular tissue cryopreservation. Therefore, the numbers might be not representative for the entire field in reproductive medicine and biology worldwide. The key ethical issue regarding fertility preservation in prepubertal boys remains the experimental nature of the intervention.

WIDER IMPLICATIONS

The revised procedures can be implemented by the multi-disciplinary teams offering and/or developing treatment strategies to preserve the fertility of prepubertal boys who have a high risk of fertility loss.

STUDY FUNDING/COMPETING INTERESTS

The work was funded by ESHRE. None of the authors has a conflict of interest.

Mutational analysis of SRD5A2: From gene to functional kinetics in individuals with steroid 5α-reductase 2 deficiency

Human steroid 5α-reductase 2 (SRD5A2) plays a determinative role in the masculinization of external genitalia. To date, approximately 114 different mutations of the SRD5A2 gene have been reported; however, little information is available about their impact on catalytic function or their three-dimensional (3D) structures. We determined the effect of point mutations on the testosterone-depend kinetic constants (K_m,app and V_max,app) and structural characteristics of SRD5A2 from Mexican patients with 46,XY-steroid 5α-reductase 2 deficiency. PCR-SSCP assays identified ten distinct gene variants and sequencing analysis identified missense mutations [p.V3I, p.S14R, p.A52T, p.F118L, p.R145W, p.R171S, p.L226P, p.F229S, p.S245Y, and p.A248V]. Mutations were re-created by site-directed mutagenesis and expressed in HEK293 cells. Functional studies demonstrated that 8 variants led to partial (K_m,app = 0.16-2.6 μM; V_max,app = 224-2640 pmol/mg P/min) or complete losses of activity compared to the wild-type enzyme (K_m,app = 0.7 μM; V_max,app = 4044 pmol/mg P/min). All the mutations were assessed using multiple software tools and the results predicted that all of the mutations were associated with disease or damage. Mapping mutations on the model of a 3D structure of SRD5A2 demonstrated alterations in contact sites with their proximal amino acids. Our data show that mutations affect the catalytic efficiency (V_max/K_m) or result in residual enzymatic activity, which could be due to erroneous interactions between amino acid residues, the substrate testosterone, or NADPH.

Potential of topological descriptors to model the retention of polychlorinated biphenyls in different gas chromatography stationary phases, including ionic liquid-based columns

The aim of this study was to develop a statistical model based on a set of intuitive topological descriptors that will help to determine the influence of the polychlorinated biphenyls (PCBs) structural features on the chromatographic behavior of these analytes in a variety of gas chromatographic stationary phases, including the highly polar ionic liquid (IL)-based SLB-IL76 and SLB-IL60 columns. The model was developed using the stepwise multiple linear regression method, and constructed through several levels of increasing complexity to make evident the relative influence of the selected descriptors. The proposed model was easy to implement and provided similar satisfactory results irrespective of the dependent variables used (i.e., retention index or retention time) or the chromatographic conditions applied (i.e., pseudo-isotherm and programmed temperature) for IL-based phases. The model also allowed the correct prediction of the elution order of selected PCBs in these and other less polar phases evaluated (i.e., SW-10, DB-17, ZB-5 and HT-8). To our knowledge, this is the first models based on topological descriptors described in the literature that provided a satisfactory fitting of the PCB behavior in IL-based phases. Our results indicated that the mechanism governing the chromatographic separation of PCBs in these highly polar columns showed significant differences compared with those observed in other less polar stationary phases.

Safety of hospital discharge before return of bowel function after elective colorectal surgery

BACKGROUND

Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function.

METHODS

A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien-Dindo classification system.

RESULTS

A total of 3288 patients were included in the analysis, of whom 301 (9·2 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4-7) and 7 (6-8) days respectively (P < 0·001). There were no significant differences in rates of readmission between these groups (6·6 versus 8·0 per cent; P = 0·499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0·90, 95 per cent c.i. 0·55 to 1·46; P = 0·659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34·7 versus 39·5 per cent; major 3·3 versus 3·4 per cent; P = 0·110).

CONCLUSION

Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients.

Safety and efficacy of non-steroidal anti-inflammatory drugs to reduce ileus after colorectal surgery

BACKGROUND

Ileus is common after elective colorectal surgery, and is associated with increased adverse events and prolonged hospital stay. The aim was to assess the role of non-steroidal anti-inflammatory drugs (NSAIDs) for reducing ileus after surgery.

METHODS

A prospective multicentre cohort study was delivered by an international, student- and trainee-led collaborative group. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The primary outcome was time to gastrointestinal recovery, measured using a composite measure of bowel function and tolerance to oral intake. The impact of NSAIDs was explored using Cox regression analyses, including the results of a centre-specific survey of compliance to enhanced recovery principles. Secondary safety outcomes included anastomotic leak rate and acute kidney injury.

RESULTS

A total of 4164 patients were included, with a median age of 68 (i.q.r. 57-75) years (54·9 per cent men). Some 1153 (27·7 per cent) received NSAIDs on postoperative days 1-3, of whom 1061 (92·0 per cent) received non-selective cyclo-oxygenase inhibitors. After adjustment for baseline differences, the mean time to gastrointestinal recovery did not differ significantly between patients who received NSAIDs and those who did not (4·6 versus 4·8 days; hazard ratio 1·04, 95 per cent c.i. 0·96 to 1·12; P = 0·360). There were no significant differences in anastomotic leak rate (5·4 versus 4·6 per cent; P = 0·349) or acute kidney injury (14·3 versus 13·8 per cent; P = 0·666) between the groups. Significantly fewer patients receiving NSAIDs required strong opioid analgesia (35·3 versus 56·7 per cent; P < 0·001).

CONCLUSION

NSAIDs did not reduce the time for gastrointestinal recovery after colorectal surgery, but they were safe and associated with reduced postoperative opioid requirement.

Serum caspase-3 levels during the first week of traumatic brain injury

OBJECTIVE

Confluence between the intrinsic and extrinsic apoptosis pathways is reached at the point of caspase-3 activation, which induces death cell. Higher serum caspase-3 levels have been recorded on day 1 of traumatic brain injury (TBI) in 30-day non-survivors compared to survivors. The objectives of this study therefore were to determine whether serum caspase-3 levels are persistently higher in non-survivors than in survivors, and whether these levels may be used to predict 30-day mortality.

DESIGN

A prospective observational study was carried out.

SETTING

Six Spanish Intensive Care Units.

PATIENTS

Patients with severe isolated TBI (defined as Glasgow Coma Scale <9 points and non-cranial Injury Severity Score <10 points).

INTERVENTIONS

Serum caspase-3 concentrations were measured on days 1, 4 and 8 of TBI.

MAIN VARIABLES OF INTEREST

Thirty-day mortality was considered as the study endpoint.

RESULTS

In comparison with non-survivors (n=34), 30-day survivors (n=90) showed lower serum caspase-3 levels on days 1 (p=0.001), 4 (p<0.001) and 8 (p<0.001) of TBI. Analysis of the ROC curves showed serum caspase-3 concentrations on days 1, 4 and 8 of TBI to have an AUC (95% CI) in predicting 30-day mortality of 0.70 (0.61-0.78; p=0.001), 0.83 (0.74-0.89; p<0.001) and 0.87 (0.79-0.93; p<0.001), respectively.

CONCLUSIONS

The novel findings of our study were that serum caspase-3 levels during the first week of TBI were lower in survivors and could predict 30-day mortality.

DNA and RNA oxidative damage are associated to mortality in patients with cerebral infarction

OBJECTIVE

Secondary injury due to oxidation may occur during ischemic stroke, possibly leading to oxidative damage to deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Higher blood concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG) (through the oxidation of guanosine from DNA) have been found in ischemic stroke patients than in healthy subjects, and in patients with versus without post-ischemic stroke depression. The present study was carried out to explore the possible association between serum DNA and RNA oxidative damage and mortality in patients with cerebral infarction.

METHODS

A prospective, multicenter observational study was carried out in the Intensive Care Units of 6 Spanish hospitals. We included patients with severe malignant middle cerebral artery infarction (MMCAI) defined as ischemic changes evidenced by computed tomography in more than 50% of the middle cerebral artery territory and a Glasgow Coma Score (GCS)<9. Serum concentrations of the three oxidized guanine species (OGS) (8-hydroxyguanine from DNA or RNA, 8-hydroxyguanosine from RNA, and 8-OHdG from DNA) on the day of MMCAI diagnosis were determined. The study endpoint was 30-day mortality.

RESULTS

We found higher serum OGS levels (p<0.001) in non-surviving (n=34) than in surviving patients (n=34). Logistic regression analyses showed serum OGS levels to be associated to 30-day mortality controlling for lactic acid, GCS and platelet count (OR=1.568; 95%CI=1.131-2.174; p=0.01).

CONCLUSIONS

The novel observation in this study is the association between global serum OGS concentration and mortality in ischemic stroke patients.