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Biomedical subjects

J Leung

Publications and source records attributed to J Leung.

81 records · Page 5Linked to original sources

Evaluation of computerized analysis of sperm movement characteristics and differential sperm tail swelling patterns in predicting human sperm in vitro fertilizing capacity.

Multivariate discriminant analysis was used to evaluate the usefulness of computer image analysis of sperm movement characteristics and differential patterns of sperm tail swelling after hypoosmotic treatment for predicting the human sperm in vitro fertilizing capacity assessed by the zona-free hamster egg penetration assay. Fifty-five semen samples, mostly normospermic, from untreated infertility clinic patients were analyzed. The % normal sperm morphology, linearity of seminal sperm movement, seminal sperm head beat frequency, mean and maximum amplitudes of lateral head displacement, and hypoosmotic sperm tail swelling patterns c, d and f were selected by multivariate discriminant analysis to be capable of discriminating the samples exhibiting the presence or the absence of sperm in vitro fertilizing capacity. The % total sperm tail swelling did not give additional information about in vitro fertilizing capacity. These preliminary data suggest that computer image analysis of sperm movement characteristics and differential evaluation of hypoosmotic sperm tail swelling might be useful for the prediction of human sperm fertility. Further prospective studies are necessary to validate their predictive functions.

Evaluation Studies as Topic↗

The accuracy of sperm concentration determination by the automated CellSoft semen analyzer before and after discontinuous Percoll gradient centrifugation.

The automated CellSoft semen analyzer identifies human spermatozoa on the basis of user-defined values for cell size and luminosity. Previous studies have shown that the non-sperm particles usually present in seminal plasma would interfere with the computerized determination of sperm concentration by the CellSoft system. Therefore, an effective method to separate the sperm from non-sperm particles would be desirable to obtain accurate determination of sperm concentration. In the present study, sperm concentrations in 72 semen samples before and after discontinuous Percoll gradient centrifugation were determined by the automated CellSoft system and the results compared with those obtained with the routine procedure using the haemocytomer according to the World Health Organization laboratory manual. The computerized measurement caused a significant overestimation when the sperm concentration in semen was less than 80 x 10(6)/ml. Processing of human semen sample by the simple two-layer discontinuous Percoll gradient centrifugation removed the majority of non-sperm particles and the overestimation by the automated CellSoft system became significant only when the sperm concentration in the final Percoll sperm preparation was less than 10 x 10(6)/ml. These findings indicate that the automated CellSoft semen analyzer has to be improved to allow for the correction of non-sperm particles in seminal plasma or processed sperm samples before it can be used to provide sufficiently accurate sperm concentration results for routine laboratory service or research purposes.

Cell Separation↗

Effectively utilizing device maintenance data to optimize a medical device maintenance program.

Methods developed by the clinical engineering community and the principles outlined by ISO regulations for the application of risk management to medical devices were integrated to provide a basis for the unique optimization system implemented into the University Health Network medical device maintenance program. Device maintenance history data stored in the database is used to conduct a risk analysis and to compute predefined benchmarks to highlight groups of equipment for which the current maintenance regime is not optimal. Using a software data research tool we are able to investigate device history data and support alterations in maintenance intervals, user training, maintenance procedures, and/or device purchasing. These alterations are justified, documented, and monitored for risk in a continuous management cycle. The predicted benefits are an overall improvement in the reliability of the devices maintained, coupled with a drop in repetitive device checks that result in no measurable benefits.

Electronic Data Processing↗

Evaluation of human sperm hyperactivated motility and its relationship with the zona-free hamster oocyte sperm penetration assay.

The authors studied hyperactivated motility of human spermatozoa as a method of evaluating capacitation by examining its relationship to results of zona-free hamster oocyte sperm penetration assays (SPA) of semen samples from 50 men attending the infertility clinic. Hyperactivated motility was assessed in the seminal plasma and after swim-up preparation of spermatozoa at 1, 3, and 24 hours of incubation in capacitation media using a computer-assisted semen analysis system equipped with a hyperactivation module. Hyperactivated motility reached a peak at 1 hour and plateaued at 3 hours. The percentage of spermatozoa in seminal plasma with star-spin hyperactivated motility was significantly lower in the group showing no penetration in the SPA. The hyperactivated motility characteristics did not differ in the groups with positive or negative penetration. Correlation analysis failed to show any significant relationship between the hyperactivated motility parameters and SPA score. When the hyperactivated motility characteristics were compared in samples with normal and abnormal semen analyses, the total percentage of spermatozoa with hyperactivated motility and the percentage with star-spin at 3 hours were significantly lower in the group with abnormal semen analysis. The data indicate that lower hyperactivated motility of spermatozoa was found in patients with a score of zero for SPA and in patients with abnormal semen analysis. It was concluded that although no direct correlations were found between the results of SPA and hyperactivated motility, evaluating hyperactivated motility may still be useful as an early indicator of capacitation abnormalities of human spermatozoa not measured by SPA.

Animals↗