Publications by authors named "Rafael F Ambar"

Article Synopsis
  • Non-obstructive azoospermia (NOA) is a prevalent and complex issue with varied treatment options and no definitive guidelines, leading to differing management practices internationally.
  • A comprehensive survey with 336 responses from specialists in 49 countries explored current medical and surgical strategies for NOA, analyzing results against existing guidelines and offering expert recommendations.
  • Key findings included diverse approaches to hormonal therapy, significant variation in sperm retrieval success rates, and differing protocols around varicocele repair and follicle-stimulating hormone cutoff levels for sperm retrieval.
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Article Synopsis
  • * Conducted from July to September 2022, a questionnaire gathered responses from 367 doctors in 49 countries, focusing on how they diagnose NOA through methods like hormone tests and genetic analyses.
  • * The survey identified that while many practices align with guidelines, significant differences in approaches were found, underscoring the need for standardized, evidence-based international guidelines for NOA evaluation.
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Article Synopsis
  • The study investigates global practices and challenges in using sperm DNA fragmentation (SDF) assays, which can affect male reproductive potential, as outlined in the latest WHO manual.
  • A survey of 436 reproductive clinicians revealed that the most popular SDF assay is TUNEL, with a significant influence from availability on their choices.
  • Clinicians see the value of SDF testing in understanding infertility but face barriers like insufficient professional guidelines and a lack of accepted reference values for interpreting SDF results.
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  • The meta-analysis investigates the effects of varicocele repair on semen parameters in infertile males, combining data from diverse studies without language restrictions.
  • A total of 351 studies were analyzed, revealing significant improvements in several semen parameters post-repair, including semen volume, sperm concentration, total sperm count, motility, and morphology, while sperm vitality showed no improvement.
  • This research is the largest of its kind and highlights the benefits of varicocele repair for male infertility, contributing valuable insights for clinical practice.
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Article Synopsis
  • The study investigates global practices for managing sperm DNA fragmentation (SDF) in infertile men, highlighting its impact on fertility and assisted reproductive technology (ART).
  • A survey collecting data from 436 reproductive experts across 55 countries revealed a common recommendation for lifestyle changes and antioxidants, with varying durations for treatment and differing management approaches for specific infertility cases.
  • The findings indicate a lack of uniformity in practices, emphasizing the need for standardized guidelines and expert consensus for treating men with elevated SDF.
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Article Synopsis
  • The study explores global practices for sperm DNA fragmentation (SDF) testing in infertile men, following its inclusion in the WHO laboratory manual.
  • A survey conducted among 436 infertility clinicians across 55 countries reveals varied testing practices, with many testing SDF in cases of unexplained infertility, recurrent pregnancy loss, and among smokers.
  • The findings highlight the need for clearer professional guidelines on SDF testing, given the diversity in current practices and the potential benefits for certain patient populations.
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Purpose: Seminal oxidative stress (OS) is a recognized factor potentially associated with male infertility, but the efficacy of antioxidant (AOX) therapy is controversial and there is no consensus on its utility. Primary outcomes of this study were to investigate the effect of AOX on spontaneous clinical pregnancy, live birth and miscarriage rates in male infertile patients. Secondary outcomes were conventional semen parameters, sperm DNA fragmentation (SDF) and seminal OS.

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Purpose: Varicocele is a common problem among infertile men. Varicocele repair (VR) is frequently performed to improve semen parameters and the chances of pregnancy. However, there is a lack of consensus about the diagnosis, indications for VR and its outcomes.

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Purpose: The success of vasectomy is determined by the outcome of a post-vasectomy semen analysis (PVSA). This article describes a step-by-step procedure to perform PVSA accurately, report data from patients who underwent post vasectomy semen analysis between 2015 and 2021 experience, along with results from an international online survey on clinical practice.

Materials And Methods: We present a detailed step-by-step protocol for performing and interpretating PVSA testing, along with recommendations for proficiency testing, competency assessment for performing PVSA, and clinical and laboratory scenarios.

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Objective: : To explore the medical literature on techniques of tissue and sperm handling after surgical retrieval for intracytoplasmic sperm injection (ICSI).

Methods: : A search was performed in PubMed and Google Scholar databases, according to a modified Preferred Reporting Items for Systemic Reviews and Meta-Analyses (PRISMA) guideline, considering the studies investigating tissue handling and sperm selection techniques for ICSI.

Results: : Overall, 42 articles were included in this study, investigating sample handling, methods for sperm selection, and the use of chemical compounds to improve sperm motility and fertilisation rates.

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Article Synopsis
  • Semen analysis is usually the first way to check if a guy has fertility issues, but it can be tricky because results can vary a lot.
  • The article emphasizes the need for better lab standards to get accurate sperm shape assessments so patients can get the right treatment.
  • It also talks about how the shape of sperm can affect fertility treatments, especially for men with very abnormal sperm.
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The current WHO 2010 manual for human semen analysis defines leukocytospermia as the presence of peroxidase-positive leukocytes at a concentration >1×10/mL of semen. Granular leukocytes when activated are capable of generating high levels of reactive oxygen species in semen resulting in oxidative stress. Oxidative stress has been correlated with poor sperm quality, increased level of sperm DNA fragmentation and low fertility potential.

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Retrograde ejaculation (RE) is a condition defined as the backward flow of the semen during ejaculation, and when present can result in male infertility. RE may be partial or complete, resulting in either low seminal volume or complete absence of the ejaculate (dry ejaculate). RE can result from anatomic, neurological or pharmacological conditions.

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Purpose: The use of antioxidants is common practice in the management of infertile patients. However, there are no established guidelines by professional societies on antioxidant use for male infertility.

Materials And Methods: Using an online survey, this study aimed to evaluate the practice pattern of reproductive specialists to determine the clinical utility of oxidative stress (OS) testing and antioxidant prescriptions to treat male infertility.

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Purpose: The objective of this scientometric analysis was to recognize the top 100 cited articles on 'Male infertility and Antioxidants' and analyze its publication characteristics.

Materials And Methods: The Scopus database was used to retrieve related articles and the top 100 identified based on citation rate.

Results: The articles were published in 56 journals between 1995 and 2019 with a median (interquartile range) citation score of 17 (5-62).

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Purpose: To compare two automated semen quality analysis systems (LensHooke® X1 PRO [X1 PRO]) and IVOS CASA) for accuracy, precision and agreement with laboratory-based manual semen analysis (MSA).

Materials And Methods: Semen samples (n=31) were obtained from normozoospermic healthy male volunteers and infertile men with a minimum abstinence period between 2-3 days. After complete liquefaction, 101 seminal aliquots were prepared and tested according to WHO 5th Edition (2010) guidelines.

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Interest in male infertility has increased, as it plays an important role in up to 50% of couples struggling with infertility, which is an estimated 48.5 million couples globally. Despite recent advances, diagnosing and treating male infertility remain a significant clinical challenge owing to complex multifactorial pathways and the diversity of treatment options.

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The advent of intracytoplasmic sperm injection (ICSI) has changed the human reproduction landscape by overcoming several limitations related to both male and female infertility factors. However, despite the development of new technologies, the live-birth rate with ICSI has not exceeded 30%. In order to improve assisted reproductive technology outcomes, advanced sperm function analysis have gained increased attention and the effects of sperm DNA fragmentation (SDF) on assisted reproduction success are being extensively studied.

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Male factor is responsible for up to 50% of infertility cases in the world. Semen analysis is considered the cornerstone of laboratory evaluation of male infertility, but it has its own drawbacks and fails to predict the male fertility potential with high sensitivity and specificity. Different etiologies have been linked with male infertility, of which sperm DNA damage has gained significant attention with extensive research on sperm function tests.

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Glutaraldehyde is used in order to improve the mechanical and immunogenic properties of biological tissues, such as bovine pericardium membranes, used to manufacture heart valve bioprostheses. Lyophilization, also known as freeze-drying, preserves biological material without damage by freezing the water content and removing ice by sublimation. Through this process, dehydrated products of high quality may be obtained; also, the material may be easily handled.

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Objective: Glutaraldehyde is currently used in bovine pericardium bioprosthesis to improve mechanical and immunogenic properties. Lyophilization is a process that may decrease aldehyde residues in the glutaraldehyde treated pericardium decreasing cytotoxicity and enhancing resistance to calcification. The aim of this study is to evaluate bioprosthetic heart valves calcification in adolescent sheep and to study the potential of lyophilization as a mechanism to protect calcification.

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HIV-1 from infected subjects has been characterized in order to provide a more accurate view of the strains that are currently found in a given region. In this report, we focused on characterizing the pol gene diversity obtained from newly diagnosed patients in Santos metropolitan area, Brazil. This region is composed of nine cities and an international port.

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