المرجع الالكتروني للمعلوماتية
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Seminal fluid analysis  
  
5337   01:36 صباحاً   date: 15-2-2016
Author : المرجع الالكتروني للمعلوماتية
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Seminal fluid analysis

 

Semen is an organic fluid, also known as seminal fluid, that usually contains spermatozoa. It is secreted by the gonads (sexual glands) and other sexual organs of male or hermaphroditic animals and can fertilize female ova. In humans, seminal fluid contains several components besides spermatozoa: proteolytic and other enzymes as well as fructose are elements of seminal fluid which promote the survival of spermatozoa and provide a medium through which they can move or "swim". The process that results in the discharge of semen is called ejaculation.

A semen analysis (plural: semen analyses) evaluates certain characteristics of a male's semen and the sperm contained in the semen. It may be done while investigating a couple's infertility or after a vasectomy to verify that the procedure was successful.

Relation to fertility

The characteristics measured by semen analysis are only some of the factors in semen quality. One source states that 30% of men with a normal semen analysis actually have abnormal sperm function. Conversely, men with poor semen analysis results may go on to father children.

Collection methods

The most common way to collect a semen sample is through masturbation, directing the sample into a clean cup. A sample may also be collected during intercourse in a special type of condom known as a collection condom. Collection condoms are made from silicone or polyurethane, as latex is somewhat harmful to sperm. Finally, if a blockage in the vas deferens is suspected to impede fertility, semen can be taken directly from the epididymis. Such a collection is called per cutaneous epididymal sperm aspiration (PESA). Alternatively, the testicular tissue itself, instead of the sperm produced can be investigated. Then, the collecting method is called TESE.

Postprocedure Care

  1. Document specimen collection time. Specimens must be received within 1 hour and examined within 3 hours.
  2. Reject semen specimens over 2 hours old.
  3. Heavy tobacco smoking and heavy coffee consumption may decrease the number of motile

spermatozoa. However, one recent study found that sperm motility increased significantly with coffee drinking and with smoking when evaluated in infertile couples.

  1. Coital lubricants reduce sperm motility.
  2. The presence of antisperm antibodies has been shown to affect sperm linearity, but not sperm motility.

Client and Family Teaching

  1. This test is used to estimate the number of sperm and evaluate fertility.
  2. Do not have intercourse or masturbate for 48 hours before specimen collection. Make sure to ejaculate at least once between 48 hours and 7 days before collection.
  3. Collect a fresh semen specimen in a plastic cup without using a condom or lubricants other then saliva. The specimen should be collected by masturbation at the institution or at home.
  4. Keep track of the time the semen was collected.
  5. For home collection: After collecting the specimen, keep the container of semen warm by putting it in a pocket next to the body.
  6. If the specimen is collected at  home, it must be delivered to the laboratory within 1 hour.
  7. Consult with your physician   before using natural or herbal remedies or medicines because

some have been shown to impair the activity of or damage sperm as well as oocytes.

Factors That Affect Results

  1. Temperature extremes decrease the sperm count.
  2. Reject semen specimens more than 1 hour old.
  3. Males with infertility tend to have increased semen volume, which  is associated          with diminished sperm count.

Other Data

Repeat testing may be necessary because results vary with samples.

Parameters

Examples of parameters measured in a semen analysis are: sperm count, motility, morphology, volume, fructose level and pH.

Sperm count

Over 15 million sperm per milliliter is considered normal, according to the WHO in 2010. Older definitions state 20 million. A lower sperm count is considered oligozoospermia. A vasectomy is considered successful if the sample is azoospermic.

Total sperm count

Total sperm count, or total sperm number, is the total number of spermatozoa in the entire ejaculate. By WHO, lower reference limit (2.5th percentile) is 39 million per ejaculate.

Motility

The motility of the sperm is evaluated. The World Health Organization has a value of 50% and this must be measured within 60 minutes of collection. WHO also has a parameter of vitality, with a lower reference limit of 60% live spermatozoa. A man can have a total number of sperm far over the limit of 20 million sperm cells per milliliter, but still have bad quality because too few of them are motile. A more specified measure is motility grade, where the motility of sperm are divided into four different

grades:

- Grade 4: Sperm with progressive motility. These are the strongest and swim fast in a straight line. Sometimes it is also denoted motility a.

- Grade 3: (non-linear motility): These also move forward but tend to travel in a curved or crooked motion. Sometimes also denoted motility b.

- Grade 2: These have non-progressive motility because they do not move forward despite the fact that they move their tails.

- Grade 1: These are immotile and fail to move at all.

Morphology

The morphology of the sperm is also evaluated. With WHO criteria as described in 2010, a sample is normal if 4% or more of the observed sperm have normal morphology.

Volume

The volume of the sample is measured, volumes between 1.0 mL and 6.5 mL are normal; WHO regards 1.5 ml as the lower reference limit. Low volume may indicate partial or complete blockage of the seminal vesicles, or that the man was born without seminal vesicles. In clinical practice, a volume of less than 2 mL in the setting of infertility and absent sperm should prompt an evaluation for obstructive azoospermia.

Fructose level

The level of fructose in the semen is measured. WHO specifies a normal level of 13 umol per sample. Absence of fructose may indicate a problem with the seminal vesicles.

pH

The pH of the sample is measured. WHO criteria specify normal as 7.2-7.8. Acidic ejaculate (lower pH value) may indicate one or both of the seminal vesicles are blocked. A basic ejaculate (higher pH value) may indicate an infection. A pH value outside of the normal range is harmful to sperm.

Liquefaction

The liquefaction is the process when the gel formed by proteins from the seminal vesicles is  and the semen becomes more liquid. It normally takes less than 20 minutes for the sample from a thick gel into a liquid. An abnormally long liquefaction (more than 30 minutes at 37 24 ċ may indicate an infection.

MOT

MOT is a measure of how many million sperm cells per ml are highly motile , that is, approximately of grade 4, or sometimes also taking grade 3 into account. Thus, it is a combination of sperm count and motility.

Total motile spermatozoa

Total motile spermatozoa (TMS) or total motile sperm count (TMSC) is a combination of sperm count, motility and volumes, measuring how many million sperm cells in an entire ejaculate are motile.

Others

The sample is tested for white blood cells. A high level of white blood cells (over 1 million per milliliter) may indicate an infection.

Abnormalities

  • Aspermia: absence of semen
  • Azoospermia: absence of sperm
  • Hypospermia: low semen volume
  • Oligozoospermia: low sperm count
  • Asthenozoospermia: poor sperm motility
  • Teratozoospermia: sperm carry more morphological defects than usual

Computer Assisted Semen Analysis (CASA) is a catch-all phrase for automatic or semi-automatic semen analysis techniques. Most systems are based on image analysis, but alternative methods exist such as tracking cell movement on a digitizing tablet. Computer-assisted techniques are most-often used for the assessment of sperm concentration and mobility characteristics, such as velocity and linear velocity. Nowadays, there are CASA systems, based on image analysis and using new techniques, with near perfect results, and doing full analysis in a few ^seconds. With some techniques, sperm concentration and motility measurements are at least as reliable as current manual methods.




علم الأحياء المجهرية هو العلم الذي يختص بدراسة الأحياء الدقيقة من حيث الحجم والتي لا يمكن مشاهدتها بالعين المجرَّدة. اذ يتعامل مع الأشكال المجهرية من حيث طرق تكاثرها، ووظائف أجزائها ومكوناتها المختلفة، دورها في الطبيعة، والعلاقة المفيدة أو الضارة مع الكائنات الحية - ومنها الإنسان بشكل خاص - كما يدرس استعمالات هذه الكائنات في الصناعة والعلم. وتنقسم هذه الكائنات الدقيقة إلى: بكتيريا وفيروسات وفطريات وطفيليات.



يقوم علم الأحياء الجزيئي بدراسة الأحياء على المستوى الجزيئي، لذلك فهو يتداخل مع كلا من علم الأحياء والكيمياء وبشكل خاص مع علم الكيمياء الحيوية وعلم الوراثة في عدة مناطق وتخصصات. يهتم علم الاحياء الجزيئي بدراسة مختلف العلاقات المتبادلة بين كافة الأنظمة الخلوية وبخاصة العلاقات بين الدنا (DNA) والرنا (RNA) وعملية تصنيع البروتينات إضافة إلى آليات تنظيم هذه العملية وكافة العمليات الحيوية.



علم الوراثة هو أحد فروع علوم الحياة الحديثة الذي يبحث في أسباب التشابه والاختلاف في صفات الأجيال المتعاقبة من الأفراد التي ترتبط فيما بينها بصلة عضوية معينة كما يبحث فيما يؤدي اليه تلك الأسباب من نتائج مع إعطاء تفسير للمسببات ونتائجها. وعلى هذا الأساس فإن دراسة هذا العلم تتطلب الماماً واسعاً وقاعدة راسخة عميقة في شتى مجالات علوم الحياة كعلم الخلية وعلم الهيأة وعلم الأجنة وعلم البيئة والتصنيف والزراعة والطب وعلم البكتريا.