Biomedical subjects

T Angelopoulos

Publications and source records attributed to T Angelopoulos.

6 recordsLinked to original sources

PubMed1999

Enhancement or initiation of testicular sperm motility by in vitro culture of testicular tissue.

OBJECTIVE: To describe different techniques of testicular tissue culture and their effect on sperm motility, mainly in cases of totally immotile spermatozoa, and to compare the effect of in vitro culture with that of motility stimulants. DESIGN: Prospective study. SETTING: University teaching hospital. PATIENT(S): Ten patients undergoing testicular biopsy for diagnostic purposes or for intracytoplasmic sperm injection. INTERVENTION(S): Dissected testicular biopsy samples and tissue blocks were cultured at 37 degrees C for up to 96 hours. Immediately after dissection, immotile testicular spermatozoa were incubated for 30 minutes in pentoxifylline and 2-deoxyadenosine. MAIN OUTCOME MEASURE(S): Sperm motility and vitality. RESULT(S): Overall, dissected samples showed improved sperm motility, which peaked within 48 hours of culture. Unlike motility, vitality declined linearly, from 56.3%+/-19% at initial assessment to 18.8%+/-11% at 96 hours. Five samples had initially immotile spermatozoa, of which four acquired motility at 48 hours. In vitro culture showed results comparable with those of incubation with pentoxifylline and 2-deoxyadenosine. Culture of tissue blocks did not improve motility or vitality compared with dissected tissue. CONCLUSION(S): The motility of testicular spermatozoa was enhanced or initiated after in vitro culture. Testicular biopsy culture may be an alternative to the use of motility stimulants to obtain motile spermatozoa for intracytoplasmic sperm injection, particularly when oocytes are not immediately available.

Adult↗

PubMed1998

Simultaneous assessment of sperm chromatin condensation and morphology before and after separation procedures: effect on the clinical outcome after in vitro fertilization.

OBJECTIVE: To look for correlations between acridine orange (AO) staining and semen parameters before and after sperm separation procedures and to assess whether the AO test predicts fertilization or pregnancy outcomes after standard IVF and intracytoplasmic sperm injection. DESIGN: Prospective study that simultaneously assesses sperm morphology and nuclear protein maturity on a cell-by-cell basis before and after preparative procedures. SETTING: University teaching hospital. PATIENT(S): Men (n = 140) undergoing diagnostic semen analysis. MAIN OUTCOME MEASURE(S): Acridine orange fluorescence of sperm nuclei, semen parameters, IVF outcome. RESULT(S): In unprocessed samples, 90% of sperm with normal heads displayed green fluorescence (mature nuclear protein); significantly lower percentages of green fluorescence were observed in sperm with abnormal heads. The percentage of mature normal sperm in the specimen correlated with motility. Sperm maturity after swim-up or Percoll gradient was significantly improved for sperm with normal or abnormal heads. The percentage of mature normal sperm correlated with motility after either Percoll or swim-up. Neither the percentages of mature nuclei nor mature normal nuclei correlated with fertilization or pregnancy outcome. CONCLUSION(S): Nuclear protein maturation correlates with sperm motility and morphology. Because morphologically normal and motile sperm are more mature, separation procedures should generate a population of sperm with the highest fertilization capacity. Acridine orange staining, however, did not predict fertilization efficiency or pregnancy outcome in IVF cycles.

Acridine Orange↗

PubMed1997

A simple and objective approach to identifying human round spermatids.

Although round spermatids have been studied extensively using staining techniques and electron microscopy, little information is available about their appearance in living conditions. We describe a method of collecting and identifying round spermatids from ejaculates and testicular biopsies. The validity of the selection procedure was confirmed by fluorescence in-situ hybridization. Based on cell size, morphological characteristics of nucleus and cytoplasm, and on the nucleus/cytoplasm ratio, we harvested a population of cells that was 84% haploid. This procedure can be applied to select spermatids for clinical or research purposes.

Biopsy↗

PubMed1997

Efficient modification of intracytoplasmic sperm injection technique for cases with total lack of sperm movement.

A rapid, simple and efficient method for selecting living spermatozoa for intracytoplasmic sperm injection (ICSI) in cases with total lack of sperm movement is described. The selection is based on a characteristic deformation of living spermatozoa exposed to hypo-osmotic conditions during short sequential exposures to modified culture medium and polyvinylpyrrolidone solution; the osmolarity of both of these solutions is reduced by one half by diluting them with an equal amount of water. The application of the sperm viability selection step in six ICSI treatment cycles with total absence of sperm movement resulted in a fertilization rate of 41.9% and the establishment of two ongoing clinical pregnancies. The method described for the selection of living spermatozoa makes it possible to reach acceptable fertilization rates and to obtain ongoing pregnancies by ICSI in cases with total lack of sperm movement. Because of its simplicity, this method can easily be improvised when the total lack of sperm movement is an unexpected finding made on the day of the planned ICSI.

Cell Separation↗

PubMed1996

Validity of the Borg perceived exertion scale for use in semirecumbent ergometry during immersion in water.

This investigation examined the validity of the Borg 15-category Ratings of Perceived Exertion (RPE) scale during semirecumbent exercise in 32 degrees C water. 9 men undertook 12 8-min. trials at 3 power outputs and 4 pedal-crank rates. The power output was distributed between the arms (20%) and legs (80%). RPEs were measured for the arms, legs, chest, and over-all body. Correlation coefficients for RPE expressed as a function of power output and gross metabolic efficiency (MEG) ranged from .56 to .83 and .54 to .70, respectively, for each pedal-crank rate. Validity coefficients were greatest at those pedal-crank rates having the highest MEG. The Borg 15-category RPE scale is valid for use during semirecumbent exercise in water.

Adult↗

PubMed1995

Metabolic and perceptual responses during arm and leg ergometry in water and air.

This investigation determined metabolic (i.e., kcal.min-1) responses and ratings of perceived exertion (RPE) for varying pedal-crank rates (PCR) and power outputs (PO) during arm and leg exercise in thermoneutral air (TA) and water (TW). Nine males (age 28.2 yr; leg cycle VO2peak 3.4 l.min-1) undertook the 24 exercise trials. During the TW trials kcal.min-1 were less (P < 0.05): at 50 W for 40 (X +/- SE; 10.9 +/- 0.8) than 50 (8.2 +/- 0.2), 60 (8.2 +/- 0.6), or 70 (7.4 +/- 0.3) rev.min-1 and at 100 W for 40 (15.2 +/- 0.7), 50 (14.0 +/- 1.1), and 60 (13.8 +/- 0.7) than 70 (12.1 +/- 0.5) rev.min-1. All other comparisons of kcal.min-1 between PCR at the three PO were not significant. During the TA trials kcal.min-1 were less (P < 0.05): at 50 W for 40 (11.4 +/- 0.3) than 60 (9.7 +/- 0.4) and 70 (9.1 +/- 0.4) rev.min-1 and for 50 (11.0 +/- 0.5) than 70 rev.min-1. During the TW trials: RPE-Arms and RPE-Overall at 50 W were lower (P < 0.05) for 40 (8.1 +/- 0.5; 8.3 +/- 0.4) than 60 (9.6 +/- 0.5; 9.8 +/- 0.6) and 70 (9.3 +/- 0.5; 9.9 +/- 0.7) rev.min-1, RPE-Legs at 50 W was lower (P < 0.05) for 40 (8.3 +/- 0.4) than 70 (9.9 +/- 0.7) rev.min-1. All other comparisons of RPE between PCR at the three PO were not significant.

Adult↗