The role of spermatozoa-zona pellucida interaction in selecting fertilization-competent spermatozoa in humans

Human fertilization begins when a capacitated spermatozoon binds to the zona pellucida (ZP) surrounding a mature oocyte. Defective spermatozoa-ZP interaction contributes to male infertility and is a leading cause of reduced fertilization rates in assisted reproduction treatments (ARTs). Human ejaculate contains millions of spermatozoa with varying degrees of fertilization potential and genetic quality, of which only thousands of motile spermatozoa can bind to the ZP at the fertilization site. This observation suggests that human ZP selectively interacts with competitively superior spermatozoa characterized by high fertilizing capability and genetic integrity. However, direct evidence for ZP-mediated sperm selection process is lacking. This study aims to demonstrate that spermatozoa-ZP interaction represents a crucial step in selecting fertilization-competent spermatozoa in humans. ZP-bound and unbound spermatozoa were respectively collected by a spermatozoa-ZP coincubation assay. The time-course data demonstrated that ZP interacted with a small proportion of motile spermatozoa. Heat shock 70 kDa protein 2 (HSPA2) and sperm acrosome associated 3 (SPACA 3) are two protein markers associated with the sperm ZP-binding ability. Immunofluorescent staining indicated that the ZP-bound spermatozoa had significantly higher expression levels of HSPA2 and SPACA3 than the unbound spermatozoa. ZP-bound spermatozoa had a significantly higher level of normal morphology, DNA integrity, chromatin integrity, protamination and global methylation when compared to the unbound spermatozoa. The results validated the possibility of applying spermatozoa-ZP interaction to select fertilization-competent spermatozoa in ART. This highly selective interaction might also provide diagnostic information regarding the fertilization potential and genetic qualities of spermatozoa independent of those derived from the standard semen analysis

Short-term results of using Lamellar Corneo-scleral patch graft for the Ahmed glaucoma valve implant surgery.

BACKGROUND: Human donor sclera is commonly used in glaucoma implant surgery to cover the external portiori of the silicone tube and prevent its erosion through the overlying conjunctiva. Corneo-scleral graft is used in this study as an alternative material for its desirable properties of being transparent, higher in tensile strength, cheap and more readily available. METHODS: Eighteen consecutive cases were implanted with the Ahmed glaucoma valve implant. The limbal portion of the silicone tube was covered by a corneo-scleral graft obtained from the corneo-scleral rim left over following corneal transplant operation. The effectiveness in protecting the tube from erosion or migration, the transparency of the patch graft and complications encountered after surgery were assessed. RESULTS: At a mean follow-up of 6 months, all tubes were well protected and no complications related to the patch graft were encountered during intra and postoperative period. All corneo-scleral grafts remained transparent and healthy at the latest follow-up. CONCLUSION: Lamellar corneo-scleral tissue from residual corneal transplant material, with its many unique properties and advantages, appears to be a cheap, easily available and effective patch graft material for glaucoma implant surgery. Further explorations and studies on this material are recommended.link_to_subscribed_fulltex

A 93-Year-Old Man With a Left Lung Mass and Exudative Pleural Effusion

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Pancreatic neuroendocrine tumours

© 2017 Hong Kong College of Radiologists. Neuroendocrine tumours (NETs) are a heterogeneous group of malignancies that can arise in different organs. Although NETs account for only 0.5% of all malignancies, their incidence has significantly increased in recent years. In the Asia Pacific region, the most common site of primary NETs is the pancreas. Many new treatment modalities have been shown to be effective in treating NETs. This study re views the diagnosis, management, and prognosis of pancreatic NETs.Link_to_subscribed_fulltex

Design and Synthesis of Heterobimetallic Ru(II)–Ln(III) Complexes as Chemodosimetric Ensembles for the Detection of Biogenic Amine Odorants

The detection of neutral biogenic amines plays a crucial role in food safety. Three new heterobimetallic Ru­(II)–Ln­(III) donor-acceptor complexes, KPrRu, KNdRu, and KSmRu, K­{[Ru^(II)(^tBubpy)­(CN)₄]₂–Ln^(III)(H₂O)₄} (where ^tBubpy = 4,4′-di-<i>tert</i>-butyl-2,2′-bipyridine), have been synthesized and characterized. Their photophysical and X-ray crystallographic data were reported in this study. These complexes were found to be selective for biogenic amine vapors, such as histamine, putrescine, and spermidine, with a detection limit down to the ppb level. The sensitivities of these complexes to the amines were recorded as ∼log <i>K</i> = 3.6–5.0. Submicron rods of the complexes, with a nanoscale diameter and microscale length, were obtained through a simple precipitation process. Free-standing polymeric films with different degrees of porosity were fabricated by blending the submicron rods with polystyrene polymer. The polymer with the highest level of porosity exhibited the strongest luminescence enhancement after amine exposure. Real time monitoring of gaseous biogenic amines was applied to real fish samples (Atlantic mackerel) by studying the spectrofluorimetric responses of the Ru­(II)–Ln­(III) blended polymer film