Technical Aspects and Clinical Limitations of Sperm DNA Fragmentation Testing in Male Infertility: A Global Survey, Current Guidelines, and Expert Recommendations

PURPOSE: Sperm DNA fragmentation (SDF) is a functional sperm abnormality that can impact reproductive potential, for which four assays have been described in the recently published sixth edition of the WHO laboratory manual for the examination and processing of human semen. The purpose of this study was to examine the global practices related to the use of SDF assays and investigate the barriers and limitations that clinicians face in incorporating these tests into their practice. MATERIALS AND METHODS: Clinicians managing male infertility were invited to complete an online survey on practices related to SDF diagnostic and treatment approaches. Their responses related to the technical aspects of SDF testing, current professional society guidelines, and the literature were used to generate expert recommendations via the Delphi method. Finally, challenges related to SDF that the clinicians encounter in their daily practice were captured. RESULTS: The survey was completed by 436 reproductive clinicians. Overall, terminal deoxynucleotidyl transferase deoxyuridine triphosphate Nick-End Labeling (TUNEL) is the most commonly used assay chosen by 28.6%, followed by the sperm chromatin structure assay (24.1%), and the sperm chromatin dispersion (19.1%). The choice of the assay was largely influenced by availability (70% of respondents). A threshold of 30% was the most selected cut-off value for elevated SDF by 33.7% of clinicians. Of respondents, 53.6% recommend SDF testing after 3 to 5 days of abstinence. Although 75.3% believe SDF testing can provide an explanation for many unknown causes of infertility, the main limiting factors selected by respondents are a lack of professional society guideline recommendations (62.7%) and an absence of globally accepted references for SDF interpretation (50.3%). CONCLUSIONS: This study represents the largest global survey on the technical aspects of SDF testing as well as the barriers encountered by clinicians. Unified global recommendations regarding clinician implementation and standard laboratory interpretation of SDF testing are crucial

Controversy and Consensus on Indications for Sperm DNA Fragmentation Testing in Male Infertility: A Global Survey, Current Guidelines, and Expert Recommendations

Purpose: Sperm DNA fragmentation (SDF) testing was recently added to the sixth edition of the World Health Organization laboratory manual for the examination and processing of human semen. Many conditions and risk factors have been associated with elevated SDF; therefore, it is important to identify the population of infertile men who might benefit from this test. The purpose of this study was to investigate global practices related to indications for SDF testing, compare the relevant professional society guideline recommendations, and provide expert recommendations. Materials and Methods: Clinicians managing male infertility were invited to take part in a global online survey on SDF clinical practices. This was conducted following the CHERRIES checklist criteria. The responses were compared to professional society guideline recommendations related to SDF and the appropriate available evidence. Expert recommendations on indications for SDF testing were then formulated, and the Delphi method was used to reach consensus. Results: The survey was completed by 436 experts from 55 countries. Almost 75% of respondents test for SDF in all or some men with unexplained or idiopathic infertility, 39% order it routinely in the work-up of recurrent pregnancy loss (RPL), and 62.2% investigate SDF in smokers. While 47% of reproductive urologists test SDF to support the decision for varicocele repair surgery when conventional semen parameters are normal, significantly fewer general urologists (23%; p=0.008) do the same. Nearly 70% would assess SDF before assisted reproductive technologies (ART), either always or for certain conditions. Recurrent ART failure is a common indication for SDF testing. Very few society recommendations were found regarding SDF testing. Conclusions: This article presents the largest global survey on the indications for SDF testing in infertile men, and demonstrates diverse practices. Furthermore, it highlights the paucity of professional society guideline recommendations. Expert recommendations are proposed to help guide clinicians

Technical aspects and clinical limitations of sperm DNA fragmentation testing in male infertility: A global survey, current guidelines, and expert recommendations

Purpose Sperm DNA fragmentation (SDF) is a functional sperm abnormality that can impact reproductive potential, for which four assays have been described in the recently published sixth edition of the WHO laboratory manual for the examination and processing of human semen. The purpose of this study was to examine the global practices related to the use of SDF assays and investigate the barriers and limitations that clinicians face in incorporating these tests into their practice. Materials and Methods Clinicians managing male infertility were invited to complete an online survey on practices related to SDF diagnostic and treatment approaches. Their responses related to the technical aspects of SDF testing, current professional society guidelines, and the literature were used to generate expert recommendations via the Delphi method. Finally, challenges related to SDF that the clinicians encounter in their daily practice were captured. Results The survey was completed by 436 reproductive clinicians. Overall, terminal deoxynucleotidyl transferase deoxyuridine triphosphate Nick-End Labeling (TUNEL) is the most commonly used assay chosen by 28.6%, followed by the sperm chromatin structure assay (24.1%), and the sperm chromatin dispersion (19.1%). The choice of the assay was largely influenced by availability (70% of respondents). A threshold of 30% was the most selected cut-off value for elevated SDF by 33.7% of clinicians. Of respondents, 53.6% recommend SDF testing after 3 to 5 days of abstinence. Although 75.3% believe SDF testing can provide an explanation for many unknown causes of infertility, the main limiting factors selected by respondents are a lack of professional society guideline recommendations (62.7%) and an absence of globally accepted references for SDF interpretation (50.3%). Conclusions This study represents the largest global survey on the technical aspects of SDF testing as well as the barriers encountered by clinicians. Unified global recommendations regarding clinician implementation and standard laboratory interpretation of SDF testing are crucial

Rembrandt'a Stüdyodan Bakmak: 17. Yüzyıl Hollanda Sanatında Özgün Bir Üretim Mekanı

Hollanda Altın Çağı'nda ticaretle zenginleşen kentli tüccar (burgher) sınıfın yükselişiyle, sanat yapıtına sahip olma arzusu toplumun geniş kesimlerine yayılmış ve Hollanda’da giderek büyüyen bir sanat pazarı oluşmuştur. Bu talebi karşılamak üzere yoğun bir üretim faaliyetinin gerçekleştiği sanatçı stüdyoları (schilderkamer) 17. yüzyıl Hollanda Sanatı araştırmacıları için önemli bir araştırma alanı olarak belirmiştir. Lonca kayıtları, sanatçı biyografileri ve envanter kayıtları gibi birincil kaynaklardan edinilen bilgilerin ortaya koyduğu sosyo ekonomik tablonun yanı sıra stüdyo, yapıtın üretildiği fiziki mekanın sınırlarını aşarak ressamın tuvaline de uzanmıştır. Sanatçılar arasında artan rekabetin etkisiyle özgün ve yetkin sanatçı kimliğinin sergilenme ihtiyacına olanak tanıyan “Stüdyosunda Sanatçı” betimleri 17. yüzyıl Hollanda resminde bir janra dönüşerek ressamlar tarafından başlı başına bir tema olarak ele alınmıştır. 17. yüzyılda tüm Hollanda içinde kentli nüfusun en kalabalık olduğu şehir olarak Amsterdam sahip olduğu ekonomik imkânlar ve ülkeler arası bağlantılar ağıyla genç ressamlar için bir çekim merkezine dönüşmüştür. Rembrandt da memleketi Leiden’daki ilk stüdyo deneyiminin ardından Amsterdam’a taşınmış, 1639’da kentin yükselen bölgesi St. Antoniesbreestraat’da satın aldığı ve 1656’daki iflasına kadar sanat kariyerinin en parlak dönemini geçirdiği evi kapsamlı bir stüdyo olarak kullanmıştır. Rembrandt henüz kariyerinin başındayken farklı şehirlerdeki ustaların yanında çıraklık eğitimini tamamlayan ressamların, sanatçının yanında kalfalık ya da stüdyo asistanlığı yaparak daha fazlasını öğrenmek istedikleri prestijli bir usta olarak ün kazanmıştır. Rembrandt’ın özgün fırçası kadar bir eğitmen olarak uyguladığı gelenek dışı stüdyo modeli de bu başarısında rol oynamıştır. Grand Tour geleneğinin bir uzantısı olarak genç ressamın eğitiminin son basamağında yer alan İtalya deneyimi karşısında kendi stüdyosunu eşdeğer bir alternatif olarak görmesi, Rönesans ustalarının yapıtlarını kopyalama yöntemiyle etüt etme yerine kendi ders materyallerini hazırlaması, öğrencilerin yalnız çalışabilmeleri için evinde fiziki mekân bölmeleri oluşturması gibi uygulamalar bu modelin özellikleri arasında sayılabilir. Bunlar arasında, Svetlana Alpers’in öncüsü olmayan bir yaklaşım olarak değerlendirdiği ve narrative drawing olarak adlandırdığı teknik ayrıca öne çıkar. Kutsal Kitap öykülerinin resmedilmeden önce öğrenciler tarafından bir tiyatro oyunu gibi canlandırıldığını öne süren bu uygulamayla öyküde yer alan figürlerin jest ve mimiklerinin tuval yüzeyine en iyi şekilde aktarılması hedeflenmiştir. Dönemin yaygın 77 stüdyo işleyişi ile Rembrandt stüdyosuna özgü dinamiklerin değerlendirileceği bu bildiride sanat ve yaşamın güçlü bir kesişimini örnekleyen Amsterdam stüdyosunun sanatçının yaşamından biyografik kayıtlar eşliğinde ele alınması amaçlanmaktadır

The role of nitric oxide in plants

Nitric oxide (NO) is the simplest, lightest and only gaseous signal transmitting molecule in animals. In recent years, there have been several comprehensive studies examining the role of NO in plant growth, metabolism and defense responses, This compilation, following a brief history of the emergence of NO research, will chiefly summarize what is currently known about NO signaling pathways and describe the potential sources of endogenous NO, its biosynthesis, metabolism and transport, particularly in plants. This work also examines the role of NO in plant growth and development, its interaction with hormones, and its activity in response to abiotic stress conditions. Many studies employing pharmacologic and biochemical methods have shown that NO is functional in programmed cell death, stoma closure, and seed germination. These functions are particularly defense-related gene expression in plants. That the role of NO in plant biology was proven by newly developed methods adds an ever growing importance to this messenger molecule