Limits...
Rotational dynamics of optically trapped human spermatozoa.

Subramani E, Basu H, Thangaraju S, Dandekar S, Mathur D, Chaudhury K - ScientificWorldJournal (2014)

Bottom Line: Optical trapping is a laser-based method for probing the physiological and mechanical properties of cells in a noninvasive manner.An integrated optical system with near-infrared laser beam has been used to analyze rotational dynamics of live sperm cells from oligozoospermic and asthenozoospermic cases and compared with controls.The linear, translational motion of the sperm is converted into rotational motion on being optically trapped, without causing any adverse effect on spermatozoa.

View Article: PubMed Central - PubMed

Affiliation: School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721 302, India.

ABSTRACT

Introduction: Optical trapping is a laser-based method for probing the physiological and mechanical properties of cells in a noninvasive manner. As sperm motility is an important criterion for assessing the male fertility potential, this technique is used to study sperm cell motility behavior and rotational dynamics.

Methods and patients: An integrated optical system with near-infrared laser beam has been used to analyze rotational dynamics of live sperm cells from oligozoospermic and asthenozoospermic cases and compared with controls.

Results: The linear, translational motion of the sperm is converted into rotational motion on being optically trapped, without causing any adverse effect on spermatozoa. The rotational speed of sperm cells from infertile men is observed to be significantly less as compared to controls.

Conclusions: Distinguishing normal and abnormal sperm cells on the basis of beat frequency above 5.6 Hz may be an important step in modern reproductive biology to sort and select good quality spermatozoa. The application of laser-assisted technique in biology has the potential to be a valuable tool for assessment of sperm fertilization capacity for improving assisted reproductive technology.

Show MeSH

Related in: MedlinePlus

ROC curve analysis indicates cutoff value which has high sensitivity and specificity for discrimination of (a) oligozoospermic sperm cells and controls (AUC = 0.8) (b) asthenozoospermic sperm cells and controls (AUC = 0.714). Sensitivity, specificity, and their 95% confidence of interval of (c) asthenozoospermic and (d) oligozoospermic cases plotted against the sperm rotational speed. (e) Comparison of ROC curves of oligozoospermic and asthenozoospermic cases.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3926395&req=5

fig3: ROC curve analysis indicates cutoff value which has high sensitivity and specificity for discrimination of (a) oligozoospermic sperm cells and controls (AUC = 0.8) (b) asthenozoospermic sperm cells and controls (AUC = 0.714). Sensitivity, specificity, and their 95% confidence of interval of (c) asthenozoospermic and (d) oligozoospermic cases plotted against the sperm rotational speed. (e) Comparison of ROC curves of oligozoospermic and asthenozoospermic cases.

Mentions: The optical tweezers set-up was used to analyze the rotational dynamics of various categories of sperm cells. As already noted, normal linear translational motion of all motile spermatozoa was halted upon trapping. Cells possessing a functional tail began to rotate under the trap in either a clockwise or anticlockwise direction (Figure 2(a)), with the rotational direction being stochastic. The rotational motion is due to the torque developed by the sperm tail force acting tangentially to the force generated within the optical trap which pins down the head of the sperm (see accompanying video in Supplementary Materials). The rotational speed of oligozoospermic and asthenozoospermic sperm cells was found to be significantly less when compared with controls (Figure 2(b)). Receiver operating characteristic (ROC) curve analysis indicated the beat frequency cut-off value to be 5.6 Hz for differentiating normal and abnormal sperm cells (both oligozoospermic and asthenozoospermic) (Figures 3(a) and 3(b)). Sensitivity and specificity values for differentiating abnormal spermatozoa from normal sperm cells at various beat frequencies are presented in Figures 3(c) and 3(d) for oligozoospermic and asthenozoospermic cases, respectively. The sensitivity and specificity for cut-off value of oligozoospermic and asthenozoospermic cases are 72% and 70% and 86% and 70%, respectively. The rotational speed or beat frequency of various categories of sperm cells also positively correlated (r = 0.73) with swimming speed of the sperm (Figure 4(a)). Swimming speeds of oligozoospermic and asthenozoospermic sperm cells were observed to be significantly lower than those of controls (Figure 4(b)). In addition, no significant differences were found between the pretrap and posttrap swimming speeds of oligozoospermic, asthenozoospermic, and normal sperm cells (Figure 4(b)). The trapping efficiency values of the tweezers for oligozoospermic, asthenozoospermic, and normal sperm cells were determined to be 96.2%, 92.2%, and 95.9%, respectively by using formula (1).


Rotational dynamics of optically trapped human spermatozoa.

Subramani E, Basu H, Thangaraju S, Dandekar S, Mathur D, Chaudhury K - ScientificWorldJournal (2014)

ROC curve analysis indicates cutoff value which has high sensitivity and specificity for discrimination of (a) oligozoospermic sperm cells and controls (AUC = 0.8) (b) asthenozoospermic sperm cells and controls (AUC = 0.714). Sensitivity, specificity, and their 95% confidence of interval of (c) asthenozoospermic and (d) oligozoospermic cases plotted against the sperm rotational speed. (e) Comparison of ROC curves of oligozoospermic and asthenozoospermic cases.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3926395&req=5

fig3: ROC curve analysis indicates cutoff value which has high sensitivity and specificity for discrimination of (a) oligozoospermic sperm cells and controls (AUC = 0.8) (b) asthenozoospermic sperm cells and controls (AUC = 0.714). Sensitivity, specificity, and their 95% confidence of interval of (c) asthenozoospermic and (d) oligozoospermic cases plotted against the sperm rotational speed. (e) Comparison of ROC curves of oligozoospermic and asthenozoospermic cases.
Mentions: The optical tweezers set-up was used to analyze the rotational dynamics of various categories of sperm cells. As already noted, normal linear translational motion of all motile spermatozoa was halted upon trapping. Cells possessing a functional tail began to rotate under the trap in either a clockwise or anticlockwise direction (Figure 2(a)), with the rotational direction being stochastic. The rotational motion is due to the torque developed by the sperm tail force acting tangentially to the force generated within the optical trap which pins down the head of the sperm (see accompanying video in Supplementary Materials). The rotational speed of oligozoospermic and asthenozoospermic sperm cells was found to be significantly less when compared with controls (Figure 2(b)). Receiver operating characteristic (ROC) curve analysis indicated the beat frequency cut-off value to be 5.6 Hz for differentiating normal and abnormal sperm cells (both oligozoospermic and asthenozoospermic) (Figures 3(a) and 3(b)). Sensitivity and specificity values for differentiating abnormal spermatozoa from normal sperm cells at various beat frequencies are presented in Figures 3(c) and 3(d) for oligozoospermic and asthenozoospermic cases, respectively. The sensitivity and specificity for cut-off value of oligozoospermic and asthenozoospermic cases are 72% and 70% and 86% and 70%, respectively. The rotational speed or beat frequency of various categories of sperm cells also positively correlated (r = 0.73) with swimming speed of the sperm (Figure 4(a)). Swimming speeds of oligozoospermic and asthenozoospermic sperm cells were observed to be significantly lower than those of controls (Figure 4(b)). In addition, no significant differences were found between the pretrap and posttrap swimming speeds of oligozoospermic, asthenozoospermic, and normal sperm cells (Figure 4(b)). The trapping efficiency values of the tweezers for oligozoospermic, asthenozoospermic, and normal sperm cells were determined to be 96.2%, 92.2%, and 95.9%, respectively by using formula (1).

Bottom Line: Optical trapping is a laser-based method for probing the physiological and mechanical properties of cells in a noninvasive manner.An integrated optical system with near-infrared laser beam has been used to analyze rotational dynamics of live sperm cells from oligozoospermic and asthenozoospermic cases and compared with controls.The linear, translational motion of the sperm is converted into rotational motion on being optically trapped, without causing any adverse effect on spermatozoa.

View Article: PubMed Central - PubMed

Affiliation: School of Medical Science and Technology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721 302, India.

ABSTRACT

Introduction: Optical trapping is a laser-based method for probing the physiological and mechanical properties of cells in a noninvasive manner. As sperm motility is an important criterion for assessing the male fertility potential, this technique is used to study sperm cell motility behavior and rotational dynamics.

Methods and patients: An integrated optical system with near-infrared laser beam has been used to analyze rotational dynamics of live sperm cells from oligozoospermic and asthenozoospermic cases and compared with controls.

Results: The linear, translational motion of the sperm is converted into rotational motion on being optically trapped, without causing any adverse effect on spermatozoa. The rotational speed of sperm cells from infertile men is observed to be significantly less as compared to controls.

Conclusions: Distinguishing normal and abnormal sperm cells on the basis of beat frequency above 5.6 Hz may be an important step in modern reproductive biology to sort and select good quality spermatozoa. The application of laser-assisted technique in biology has the potential to be a valuable tool for assessment of sperm fertilization capacity for improving assisted reproductive technology.

Show MeSH
Related in: MedlinePlus