نتایج جستجو برای: gradient selected sperm

تعداد نتایج: 533627  

Journal: :Human reproduction 2004
Carole Marchetti Miguel-Angel Gallego André Defossez Pierre Formstecher Philippe Marchetti

BACKGROUND Detection of apoptosis in sperm samples may help evaluate sperm quality. Recently, it has been suggested that in some ejaculated sperm populations, apoptosis is caspase dependent. The aim of this study was to investigate the presence of activated caspases and examine possible correlations with apoptosis and sperm parameters in semen samples prepared for IVF. METHODS To detect activ...

Journal: :Journal of biomedical optics 2006
Jaclyn M Nascimento Elliot L Botvinick Linda Z Shi Barbara Durrant Michael W Berns

This study examines the use of optical trapping as a quantitative measure of sperm motility. The effects of laser trap duration and laser trapping power on sperm motility are described between sperm swimming force, swimmimg speed, and speed of progression (SOP) score. Sperm (SOP scores of 2-4) were trapped by a continuous-wave 1064 nm single-point gradient laser trap. Trap duration effects were...

Journal: :Fertility and sterility 2011
Luke Simon Deborah Lutton Joanne McManus Sheena E M Lewis

OBJECTIVE To evaluate sperm DNA fragmentation and semen parameters to diagnose male factor infertility and predict pregnancy after IVF. DESIGN Prospective study. SETTING Academic research laboratory. PATIENT(S) Seventy-five couples undergoing IVF and 28 fertile donors. INTERVENTION(S) Sperm DNA fragmentation was measured by the alkaline Comet assay in semen and sperm after density gradi...

Journal: :Human reproduction 2014
Lara Tamburrino Sara Marchiani Federico Minetti Gianni Forti Monica Muratori Elisabetta Baldi

STUDY QUESTION Does CatSper have a role in the achievement of human sperm motility and in the Progesterone (P)-induced acrosome reaction (AR)? SUMMARY ANSWER CatSper1 expression is associated with human sperm progressive motility and the P-induced AR; it may have a role in the pathogenesis of asthenozoospermia. WHAT IS KNOWN ALREADY Knockout mice for any of the Catsper family genes fail to ...

Journal: :Biomedical microdevices 2007
Bing Shao Linda Z Shi Jaclyn M Nascimento Elliot L Botvinick Mihrimah Ozkan Michael W Berns Sadik C Esener

Sperm motility is an important concept in fertility research. To this end, single spot laser tweezers have been used to quantitatively analyze the motility of individual sperm. However, this method is limited with throughput (single sperm per spot), lacks the ability of in-situ sorting based on motility and chemotaxis, requires high laser power (hundreds of milliWatts) and can not be used to dy...

Journal: :Journal of andrology 1994
C Xu D R Rigney D J Anderson

The purpose of this study was to characterize highly enriched human spermatozoa membrane proteins by two-dimensional electrophoresis and computer image analysis. Sperm membrane proteins were extracted by detergent solubilization from three different preparations: 1) washed semen cells following centrifugation and three wash steps in Ham's F-10 medium (the standard sperm preparation, which is co...

Journal: :Journal of cell science 2013
Adán Guerrero Jesús Espinal Christopher D Wood Juan M Rendón Jorge Carneiro Gustavo Martínez-Mekler Alberto Darszon

In many broadcast-spawning marine organisms, oocytes release chemicals that guide conspecific spermatozoa towards them through chemotaxis. In the sea urchin Lytechinus pictus, the chemoattractant peptide speract triggers a train of fluctuations of intracellular Ca(2+) concentration in the sperm flagella. Each transient Ca(2+) elevation leads to a momentary increase in flagellar bending asymmetr...

Journal: :Fertility and sterility 2005
Tamer M Said Ashok Agarwal Rakesh K Sharma Anthony J Thomas Suresh C Sikka

OBJECTIVE To investigate the role of DNA damage induced by beta-nicotinamide adenine dinucleotide phosphate (NADPH) in human spermatozoa. DESIGN Prospective controlled study. SETTING Male infertility clinic at the Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, Ohio. PATIENT(S) Twenty-eight men undergoing infertility screening. INTERVENTION(S) Chemiluminescence as...

Journal: :Wiley interdisciplinary reviews. Systems biology and medicine 2011
Linda Z Shi Jaclyn Nascimento Elliot Botvinick Barbara Durrant Michael W Berns

Optical trapping is a noninvasive biophotonic tool that has been developed to study the physiological and biomechanical properties of cells. The custom-designed optical system is built to direct near-infrared laser light into an inverted microscope to create a single-point three-dimensional gradient laser trap at the microscope focal point. A real-time automated tracking and trapping system (RA...

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