Presence of M540 bodies in human semen: techniques to detect them require attention

20 06 2013

To the Editor:

We read with interest the paper by Gomez-Lopez et al., published in Fertility and Sterility (1), in which the authors investigated the presence of merocyanine 540 bodies (M540 bodies) and their impact on the detection of sperm apoptotic markers, including sperm DNA fragmentation.
In this paper the authors report that the incidence of M540 bodies in the semen of infertile men is very low (about 1%) and that their occurrence does not affect the determination of sperm DNA Fragmentation (sDF) by TUNEL coupled to flow cytometry.

These results contrast with previous data by our group that first described M540 bodies (2) and later on demonstrated that they are apoptotic bodies of testicular origin (3). Indeed, we found that M540 bodies can be present in high amount in semen of sub/infertile men (2, 3) and that they heavily flaw the determination of TUNEL positive sperm by flow cytometry (4). We believe that the cause of such discrepancies is the technique that the authors used to reveal M540 bodies in TUNEL processed samples. They first stained by merocyanine 540 and then washed and processed samples by TUNEL assay. By this procedure, merocyanine labeling is washed away from the bodies, since M540 does not bind in a stable (covalent) manner to bodies. As a consequence, they failed to detect M540+ elements, not because of their absence but because of the loss of merocyanine staining. Read the rest of this entry »





Letter regarding use of laptop computers connected to internet through Wi-Fi decreases human sperm motility and increases sperm DNA fragmentation.

3 02 2012

To the Editor:

We read with great interest the article by Avendaño et al (1), “Use of laptop computers connected to internet through Wi-Fi decreases human sperm motility and increases sperm DNA fragmentation.” We want to congratulate the authors for their original and interesting work. However, this study has also raised a few questions.

First of all, the issue of sperm analysis method should be addressed. Indeed, sperm analysis was performed manually before selection, after swim up, and after 4 hours of incubation under the computer or not (control group). Despite efforts towards improvement and standardization of laboratory procedures (2), manual sperm analysis still suffers from a lack of precision and accuracy (3), particularly when counting progressive motile spermatozoa in an enriched supernatant. Moreover, sperm analysis was conducted here by a single observer and apparently not repeated, which leads to a high risk of intra observer variability. We also would like the authors to precise if the study was operator-blinded or if the operator was aware of the origin of the samples he was assessing. All these limitations could constitute a bias and prevent from relevant interpretation of the results. Could the authors consider automated sperm analysis as a reliable alternative in order to improve reproducibility and precision of their results? (4) Moreover, CASA could bring new insights into a potential WiFi-induced sperm motility alteration and kinetics modification. Read the rest of this entry »





Re: Use of laptop computers connected to internet through Wi-Fi decreases human sperm motility and increases sperm DNA fragmentation

12 01 2012

To the Editor:

We read with interest the article “Use of laptop computers connected to internet through Wi-Fi decreases human sperm motility and increases sperm DNA fragmentation” by Avendano et al.(1). However, we do actually think that the evidence presented in this paper cannot support the claim that the observed effects are nonthermal and caused by exposure to a Wi-Fi radiofrequency electromagnetic field.

Keeping constant the temperature under the computer by an air conditioning system is not sufficient to ensure homogeneity of the temperatures within the experimental area, since the heat source from the laptop is not homogenous itself, and to exclude that there is no local variation in the samples temperatures. Read the rest of this entry »