Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Air dried sperm could allow home storage

01.07.2003


A novel method of preserving sperm through air drying is showing initial promise and has the potential to revolutionize sperm storage, allowing men awaiting in vitro fertilization (IVF) to take care of their sperm at home.



Dr Daniel Imoedemhe, a consultant in reproductive medicine and endocrinology, working in Saudi Arabia, told the annual meeting of the European Society of Human Reproduction and Embryology, that for the first time studies on human embryos fertilized with air-dried sperm have shown that the new technique does not impair the early stages of embryo cell division

Dr Imoedemhe, from Erfan and Bagedo Hospitals, Centre for Assisted Reproduction, Jeddah, said that in the past it was believed that sperm "died" when allowed to dry in air because they were no longer motile and therefore unable to penetrate an egg. "But with the technique intracytoplasmic sperm injection (ICSI), the loss of motility doesn’t necessarily mean the loss of ability to fertilize an egg, since this is largely dependent on the DNA (genetic material) that is tightly packed into the sperm head. We believe our study confirms that sperm DNA is resistant to damage by air drying."


Established methods of sperm preservation require special freezing equipment that needs careful programming to deliver controlled cooling so that the sperm are not destroyed by cooling too fast or too slowly. Sperm also need to be stored with a cryoprotectant (a special chemical that protects sperm from the adverse effects of cooling to low temperatures), which then needs to be removed prior to use.

Sperm are stored in large liquid Nitrogen tanks that require regular top-ups to ensure that they remain in the desired condition. The tanks are expensive, large and occupy a great deal of laboratory space. In the current system, in order to prevent mis-identification during recovery from storage tanks, a rigorous labelling and coding system is required.

"These methods are time-consuming and cumbersome compared to our simple technique of air-drying that just requires re-suspension before use," said Dr Imoedemhe. "The process can be further simplified by allowing patients to take responsibility for storing their air-dried sperm at home."

The new air-drying technique involves smearing a sample pellet of washed sperm on to a glass slide and then leaving it to dry for two to three hours in a laminar flow cabinet that allows a directional flow of filtered air to ensure that the sample remained uncontaminated by airborne dust or micro-organisms. The dried sperm can then be stored at normal room temperature or in a normal refrigerator and do not seem to require any other special storage conditions. Just prior to injection by ICSI into an egg, the sperm film can be re-suspended with a large drop of special biological medium (similar to that in which the eggs are held in order to avoid osmotic changes).

The present study compared early embryos that had been formed from 24 oocytes subjected to ICSI with re-suspended dried sperm (the experimental group) with 108 oocytes that that had been subjected to ICSI with fresh sperm (the therapeutic group). The study involved nine couples where the eggs taken from wives were injected with their husband’s sperm.

Researchers found that drying did not prevent the sperm from taking part in the first stages of fertilization that are considered signs of normal development as 92 % of the eggs underwent the formation of two pronuclei (microscopically visible structures can be seen in the egg representing the genetic contributions from the mother and father) in the egg and 86% developed into cleaved embryos (the early stages of cell division).

But although drying did not seem to interfere with fertilization, it was found that 72 hours after sperm injection, the therapeutic group (eggs fertilized with fresh un-dried sperms) had significantly more embryos advancing to the eight or more cell stage than the experimental group (air dried sperm) – 50.5% versus 18.2%.

However Dr Imoedemhe believes this may have more to do with the differences in experimental procedure necessitated by the difficulty of acquiring fresh mature eggs for the experimental group, than the effects of air-drying. In the treatment group all the eggs were mature (at metaphase II), whereas in the air-dried group the eggs were immature (at metaphase I) and had to be matured outside before ICSI. It is thought that such immature eggs may have less potential for development after fertilization compared to normally matured eggs.

"We are greatly encouraged that even under these experimental conditions out of 24 oocytes in the air-dried group, two embryos developed to the blastocyst stage – this is the last free floating stage of development before implantation in the uterine cavity. It’s thought that only the best quality embryos can continue developing outside the body to this stage," he said.

Dr Imoedemhe believes the widespread introduction of air drying would allow stored sperm to be transported without the need for specialized equipment, relieve laboratories of the responsibility of caring for preserved sperm and allow decisions and responsibilities for disposal to be borne by owners in the privacy of their own homes.

Storing sperm at home also removes fear of the potential transmission of HIV and other viral diseases (often expressed by patients) if samples from infected individuals were stored inadvertently with those from uninfected people.

Dr Imoedemhe said the next stage is to test the air-drying technique in mature (metaphase II) eggs to see whether division happens at the same rate as with fresh sperm and then to carry out pre-implantation studies on resulting embryos to ensure no adverse genetic effects have been induced by sperm drying.


###
Abstract no: O-178 (Tuesday, 17.30hrs CET, Europa room)

Further information:
Margaret Willson, information officer
Tel: 44-0-1536-772181
Fax: 44-0-1536-772191
Mobile: 44-0-7973-853347
Email: m.willson@mwcommunications.org.uk

Press Office: (Sunday 29 June -Wednesday 2 July)
Margaret Willson, Emma Mason, Maria Maneiro, Janet Blümli
Tel: 34-917-220-501 or 34-917-220-502
Fax: 34-917-220-503

Emma Mason | EurekAlert!
Further information:
http://www.eshre.com/

More articles from Health and Medicine:

nachricht New malaria analysis method reveals disease severity in minutes
14.08.2017 | University of British Columbia

nachricht New type of blood cells work as indicators of autoimmunity
14.08.2017 | Instituto de Medicina Molecular

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>