Publications by authors named "Sarah Martins Da Silva"

Infertility is estimated to affect more than 50 million couples around the world, with male factor accounting for half of these cases, yet there is a notable absence of effective treatment options for men, other than in-vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI). This review considers unlicensed and empirical treatments used for male subfertility, including hormonal therapy, phosphodiesterase inhibitors, and antioxidants. Compounds generally demonstrate variable improvements in sperm function but benefits for fertility are less clear.

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Male contraceptive options and infertility treatments are limited, and almost all innovation has been limited to updates to medically assisted reproduction protocols and methods. To accelerate the development of drugs that can either improve or inhibit fertility, we established a small molecule library as a toolbox for assay development and screening campaigns using human spermatozoa. We have profiled all compounds in the Sperm Toolbox in several automated high-throughput assays that measure stimulation or inhibition of sperm motility or the acrosome reaction.

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Purpose: Many countries prohibit payment for gamete donation, which means fertility clinics do not have to compensate donors. However, acquiring and utilizing donor sperm can still be expensive for fertility clinics. This study evaluates international fertility workers' views on charging patients for altruistically donated sperm.

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Sperm cryopreservation for men with severely impaired spermatogenesis is one of the commonest reasons for short-term sperm storage, usually in advance of fertility treatment. Cryopreservation is generally very effective, although not all spermatozoa survive the process of freezing and thawing. This review considers various aspects of freezing sperm, including an overview of methods, appropriate use of cryoprotectants and practical considerations, as well as oxidative stress and mechanisms of cell cryodamage.

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Compared to women, increasing male age is not accompanied by such marked changes in reproductive function but changes certainly do happen. These include alterations to the hypothalamo-pituitary-testicular axis, with resultant implications for testosterone production and bioavailability as well as spermatogenesis. There is a decline in sexual function as men age, with a dramatic increase in the prevalence of erectile dysfunction after the age of 40, which is a marker for both clinically evident as well as covert coronary artery disease.

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Progesterone and prostaglandin E1 are postulated to trigger the human sperm acrosome reaction (AR). However, their reported efficacy is very variable which likely, in part, reflects the plethora of experimental conditions and methodologies used to detect this physiologically relevant event. The purpose of this study was to develop an assay for the robust induction and objective measurement of the complete AR.

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Article Synopsis
  • Biomedical science is improving in transparency and reproducibility, which is crucial for research involving semen analysis.
  • Two key documents have been released: the WHO Laboratory Manual and the International Standard ISO 23162:2021, both focusing on semen examination protocols.
  • It is recommended that authors adhere to these guidelines when publishing their studies, ideally using a provided checklist for proper compliance.
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Infertility is a time-consuming and exhaustive process, which disproportionally affects women. Although concerns have been raised about deficiencies in clinical evaluation of infertile men, there is currently little published data documenting this. A SurveyMonkey questionnaire was therefore created to capture current clinical practice of fertility specialists working in IVF clinics.

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Fertility preservation has gained momentum in recent years. As cancer survival rates improve, late effects of loss of gonadal function have increased the need to consider fertility preservation. NICE recommends offering cryopreservation of gametes or embryos to patients undergoing gonadotoxic therapy, highlighting that this should be extrapolated to those with non-malignant conditions that pose a risk to fertility.

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Artificial oocyte activation, most commonly using calcium ionophore, is a treatment add-on utilized to avoid recurrence of abnormally low or total failed fertilization following in vitro fertilization/intracytoplasmic sperm injection. It aims to modify defective physiological processes, specifically calcium-mediated cell signaling that are critical to events required for fertilization. Routine application of artificial oocyte activation is neither required nor recommended; however, it represents an invaluable intervention for a subgroup of patients affected by sperm-related oocyte activation deficiency.

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In IVF, eggs and sperm are added together for fertilisation to occur whereas ICSI involves injecting a single sperm into each egg. ICSI is very effective where sperm count or swimming is poor (male infertility) but is slightly riskier than IVF in terms of health problems in children, although these risks are small. However, the risk of no eggs fertilising is higher for IVF compared to ICSI and couples undertaking fertility preservation, for example, before cancer treatment, usually only have time for one attempt.

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Study Question: Can a high-throughput screening (HTS) platform facilitate male fertility drug discovery?

Summary Answer: An HTS platform identified a large number of compounds that enhanced sperm motility.

What Is Known Already: Several efforts to find small molecules modulating sperm function have been performed but none have used high-throughput technology.

Study Design, Size, Duration: Healthy donor semen samples were used and samples were pooled (3-5 donors per pool).

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Study Question: What is the clinical-effectiveness and safety of the endometrial scratch (ES) procedure compared to no ES, prior to usual first time in vitro fertilisation (IVF) treatment?

Summary Answer: ES was safe but did not improve pregnancy outcomes when performed in the mid-luteal phase prior to the first IVF cycle, with or without intracytoplasmic sperm injection (ICSI).

What Is Known Already: ES is an 'add-on' treatment that is available to women undergoing a first cycle of IVF, with or without ICSI, despite a lack of evidence to support its use.

Study Design, Size, Duration: This pragmatic, superiority, open-label, multi-centre, parallel-group randomised controlled trial involving 1048 women assessed the clinical effectiveness and safety of the ES procedure prior to first time IVF, with or without ICSI, between July 2016 and October 2019.

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A prevalent cause of sperm dysfunction in male infertility patients is the overproduction of reactive oxygen species, an attendant increase in lipid peroxidation and the production of cytotoxic reactive carbonyl species such as 4-hydroxynonenal. Our previous studies have implicated arachidonate 15-lipoxygenase (ALOX15) in the production of 4-hydroxynonenal in developing germ cells. Here, we have aimed to develop a further mechanistic understanding of the lipoxygenase-lipid peroxidation pathway in human spermatozoa.

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Unlabelled: Fifteen percent of couples are globally estimated to be infertile, with up to half of these cases attributed to male infertility. Reactive oxidative species (ROS) are known to damage sperm leading to impaired quantity and quality. Although not routinely assessed, oxidative stress is a common underlying pathology in infertile men.

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Fertility services were significantly curtailed or suspended as an initial response to the coronavirus (COVID-19) pandemic earlier this year, following guidance from European Society for Human Reproduction and Embryology (ESHRE) and the American Society for Reproductive Medicine (ASRM) as well as a General Direction (GD0014) issued by the Human Fertilisation and Embryo Authority (HFEA). It is difficult to argue with triage of medical care and resources in the face of anticipated overwhelming demand, but this situation resulted in considerable distress, as shown by a change.org petition opposing ASRM recommendations, which has gathered over 21,000 signatures to date.

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Oxidative stress is detrimental to spermatozoa and is acknowledged to be a common pathology in infertile men. Antioxidant supplements, therefore, represent a logical therapeutic approach, although the recent Cochrane review recommends cautious interpretation of publications and findings to date. This commentary considers whether male fertility supplements have a place in current reproductive medicine practice.

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Background: Intensive research on sperm ion channels has identified members of several ion channel families in both mouse and human sperm. Gene knock-out studies have unequivocally demonstrated the importance of the calcium and potassium conductances in sperm for fertility. In both species, the calcium current is carried by the highly complex cation channel of sperm (CatSper).

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Background And Purpose: Asthenozoospermia is a leading cause of male infertility, but development of pharmacological agents to improve sperm motility is hindered by the lack of effective screening platforms and knowledge of suitable molecular targets. We have demonstrated that a high-throughput screening (HTS) strategy and established in vitro tests can identify and characterise compounds that improve sperm motility. Here, we applied HTS to identify new compounds from a novel small molecule library that increase intracellular calcium ([Ca ] ), promote human sperm cell motility, and systematically determine the mechanism of action.

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Human sperm show a variety of different behaviours (types of motility) that have different functional roles. Previous reports suggest that sperm may reversibly switch between these behaviours. We have recorded and analysed the behaviour of individual human sperm (180 cells in total), each cell monitored continuously for 3-3.

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Study Question: Does a man (patient 1) with a previously described deficiency in principle cation channel of sperm (CatSper) function have a mutation in the CatSper-epsilon (CATSPERE) and/or CatSper-zeta (CATSPERZ) gene?

Summary Answer: Patient 1 has a homozygous in-frame 6-bp deletion in exon 18 (c.2393_2398delCTATGG, rs761237686) of CATSPERE.

What Is Known Already: CatSper is the principal calcium channel of mammalian spermatozoa.

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