An analysis of the frequency of Y-chromosome microdeletions and the determination of a threshold sperm concentration for genetic testing in infertile men.

OBJECTIVE: To describe the prevalence of Y-chromosome microdeletions in a multi-ethnic urban population in London, UK. To also determine predictive factors and a clinical threshold for genetic testing in men with Y chromosome microdeletions. PATIENTS AND METHODS: A retrospective cohort study of 1473 men that were referred to a tertiary Andrology centre with male factor infertility between July 2004 and December 2016. All had a genetic evaluation, hormonal profile and 2 abnormal semen analyses. Those with abnormal examination findings also had targeted imaging performed. RESULTS: The prevalence of microdeletions was 4% (n = 58) in this study. These microdeletions were partitioned into the following regions: Azoospermia factors (AZF); AZFc (75%), AZFb+c (13.8%), AZFb (6.9%), AZFa (1.7%), and partial AZFa (1.7%). A high follicle-stimulating hormone level (P < 0.001) and a low sperm concentration (P < 0.05) were both found to be significant predictors for the identification of a microdeletion. Testosterone level, luteinising hormone level and testicular volume did not predict the presence of a microdeletion. None of the men with an AZF microdeletion had a sperm concentration of >0.5 million/mL. Lowering the sperm concentration threshold to this level retained the high sensitivity (100%) and increased the specificity (31%). This would produce significant cost savings when compared to the European Academy of Andrology/European Molecular Genetics Quality Network and European Association of Urology guidelines. The surgical sperm retrieval (SSR) rate after microdissection testicular sperm extraction was 33.2% in men with AZFc microdeletion. CONCLUSIONS: The prevalence of Y-chromosome microdeletions in infertile men appears to vary between populations and countries. A low sperm concentration was a predictive factor (P < 0.05) for identifying microdeletions in infertile males. A threshold for genetic testing of 0.5 million/mL would increase the specificity and lower the relative cost without adversely affecting the sensitivity. The rate of SSR was lower than that previously described in the literature.

Effects of different focus of attention rehabilitative training on gait performance in Multiple Sclerosis patients.

The present investigation studied the effects of different focus of attention training on gait performance. Twelve volunteers with Multiple Sclerosis and with an average disability score (Expanded Disability Status Scale=6.5) were selected from a Medical School and took part in a three-phase intervention including baseline, internal focus, and external focus, for eight weeks. In the baseline condition, the participants walked on a treadmill without any information. In the first (internal-focus) intervention they focused on foot performance and in the second (external-focus) intervention they focused on external markers and auditory information. The results of within-group analysis of variance showed that the external intervention was significantly (p<.05) better than the other conditions for stride length, step length, step speed, and gait energy expenditure, but not for force and stride timing (p>.05). In conclusion, the second (external-focus) intervention was found to be an appropriate perceptual training method and to result in improvements in some of the gait performance parameters.