Spermyogram

CASA terminology

This article describes some standard terminology for variables measured by CASA systems. In addition to the parameters you can obtain in the SpermCell ™ report, you can find the parameters found in the reports from CASA systems.

1. VCL, curvilinear velocity (µm/s). Time-averaged velocity of a sperm head along its actual curvilinear path, as perceived in two dimensions in the microscope. A measure of cell vigour.

2. VSL, straight-line (rectilinear) velocity (µm/s). Time-averaged velocity of a sperm head along the straight line between its first detected position and its last.

3. VAP, average path velocity (µm/s). Time-averaged velocity of a sperm head along its average path. This path is computed by smoothing the curvilinear tra- jectory according to algorithms in the CASA instrument; these algorithms vary between instruments, so values may not be comparable among systems.

4. ALH, amplitude ofl ateral head displacement(µm). Magnitude of lateral displacement of a sperm head about its average path. It can be expressed as a maximum or an average of such displacements. Different CASA instruments compute ALH using different algorithms, so values may not be comparable among systems.

5. LIN, linearity. The linearity of a curvilinear path,VSL/VCL.

6. WOB, wobble. A measure of oscillation of the actual path about the average path, VAP/VCL.

7. STR, straightness. Linearity of the average path, VSL/VAP.

8. BCF, beat cross frequency(Hz).The average rate at which the curvilinear path crosses the average path.

9. MAD, mean angular displacement (degrees).The time averaged absolute values of the instantaneous turning angle of the sperm head along its curvilinear trajectory.

Note: Different CASA instruments use different mathematical algorithms to compute many of these movement variables. The comparability of measurements across all instruments is not yet known.

*This entire article is taken from the WHO Laboratory Handbook-Examination and processing of human semen, from pages 138 and 139 of the 5th Edition. To the complete of the book and references to the information given http://apps.who.int/iris/bitstream/10665/44261/1/9789241547789_eng.pdf?ua=1

**Images used in this article are taken from http://newshawktime.com web site.

Reactive Oxygen Species

Reactive Oxygen Species

The excessive generation of reactive oxygen species (ROS) and the presence of high activities of cytoplasmic enzymes, such as creatine phosphokinase, may reflect abnormal spermatozoa with excess residual cytoplasm in the midpiece (Rao et al., 1989; Gomez et al., 1996; Aitken et al., 2004).

Indication of factors causing the formation of Reactive Oxygen Radicals

Reactive oxygen species are metabolites of oxygen and include

  • The superoxide anion,
  • Hydrogen peroxide,
  • Hydroxyl and hydroperoxyl radicals,
  • Nitric oxide

When present in excess, they can initiate pathological changes by induc- ing oxidative damage to cellular lipids, proteins and DNA (Griveau & Le Lannou, 1997; Aitken et al., 2003; Henkel et al., 2004). Most cells are equipped with either enzymatic antioxidant systems (superoxide dismutase, glutathione peroxidase and catalase) or non-enzymatic antioxidant systems (uric acid, ascorbic acid, D-toco- pherol), and when these defences are overwhelmed, sperm function is impaired (Agarwal et al., 2004).

In the human ejaculate, reactive oxygen species are produced by both sperma- tozoa (Aitken & Clarkson, 1987; Alvarez et al., 1987; Iwasaki & Gagnon, 1992) and leukocytes (Aitken & West, 1990). Seminal plasma possesses free radical anti- oxidant scavengers and antioxidant enzymes, which may be deficient in some men (Jones et al., 1979; Smith et al., 1996). Thus the removal of seminal plasma during the preparation of spermatozoa for assisted conception (see Chapter 5) may render these cells vulnerable to oxidative attack. High ROS production may cause peroxidative damage and loss of sperm function, as well as DNA damage in both the nuclear and mitochondrial genomes (Sawyer et al., 2003). Sperm survival assays are frequently used to assess the quality of human spermatozoa. The results of such assays are highly correlated with the lipid peroxidation status of the spermatozoa (Gomez et al., 1998).

A chemiluminescent procedure, employing probes such as luminol or lucigenin, may be used to measure ROS production and the redox activity of human spermatozoa.

*This entire article is taken from the WHO Laboratory Handbook-Examination and processing of human semen, from pages 142 and 143 of the 5th Edition. To the complete of the book and references to the information given http://apps.who.int/iris/bitstream/10665/44261/1/9789241547789_eng.pdf?ua=1

**Images used in this article are taken from http://www.humineral.com web site.