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Posts Tagged ‘sperm’

STEM CELLS MAY CONQUER INFERTILITY IN CANCER SURVIVORS

In STEM CELLS IN THE NEWS on December 10, 2012 at 9:00 am

sperm stem cells

Cancer survivors, who have undergone radiation or chemotherapy treatments, are often met with the dismal reality of infertility.  Oncologists, for years, have been unable to address the long-term and permanent consequences of these life saving treatments.  New research conducted on the concept of using spermatogonial stem cells to restore fertility has proven to be a success in male primates and is getting closer to clinical trials.

-DG

A UTSA professor has now demonstrated that it is possible to remove testicular stem cells from a monkey prior to chemotherapy, freeze them and later, after cancer treatments, transplant these cells where they can restart sperm production and restore fertility.  UTSA Assistant Professor Brian Hermann worked in collaboration with researchers at the University Of Pittsburgh School Of Medicine Magee-Women’s Research Institute (MWRI) on a technique that might be used to make male cancer patients fertile using their own spermatogonial stem cells.

“This is a really exciting milestone for this research,” said John McCarrey, director of the San Antonio Cellular Therapeutics Institute. “This is the first time that anybody has been able to show the concept works in a primate model, and that is an important step in moving the research forward to clinical trials.”

While men facing cancer treatments, which could cause infertility, are able to store their own sperm for future use in the fertility clinic, this is not an option for boys before puberty who are not yet making sperm. But, all pre-pubertal boys have spermatogonial stem cells (SSCs) in their testes, which could be used for transplantation.  The concept of using spermatogonial stem cells to restore fertility was first introduced in the mid-1990s by University of Pennsylvania scholar Ralph L. Brinster. Since that time, scholars have been working to demonstrate the concept is viable.  But, more work is required. The research must overcome a number of hurdles before it can become a common clinical practice.  “This research demonstrates the proof of principle — that the concept works in primates and has a good chance of working in humans,” said Hermann. “We need to better understand the optimal timing of transplantation, how to prepare testicular stem cells for transplantation and make them safe for transplantation, and how to maximize their ability to restart sperm production.”  But, it’s difficult for researchers to know when clinical trials will begin, since the removal and storage of spermatogonial stem cells currently is a rare practice worldwide.

“There are currently only a handful of clinics around the world that will remove and preserve testicular stem cell samples from pre-pubertal patients, and that limits the availability of candidates,” said Hermann. “Until more clinics get on board and save stem cells for patients, we are limited in what we can do to test transplantation in clinical trials.”

Hermann joined the UTSA College of Sciences faculty in summer 2011, following a post-doctoral fellowship at MWRI alongside Associate Professor Kyle Orwig. At UTSA, he is continuing to focus his research on basic and translational studies of spermatogonial stem cells to preserve fertility in boys treated for cancer and related diseases.  “For a long time, oncologists have been unable to address the long-term consequences of life-saving chemotherapy and radiation treatments such as infertility,” said Hermann. “That is now beginning to change as laboratory research such as this study provides new experimental options for patients facing infertility after cancer.”

Hermann’s research is funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the Max and Minnie Tomerlin Voelcker Fund, and UTSA.

http://bio.utsa.edu/news/brian-hermanns-stem-cell-research-provides-hope-for-infertile-cancer-surviv/#.UMXVuXf4J8g

STEM CELL TRANSPLANTS RESTORE FERTILITY

In SCIENCE & STEM CELLS on November 5, 2012 at 8:06 pm

Stem cells

Stem Cell Transplants Restore Fertility in Monkeys

Injections of banked sperm-making stem cells can restore fertility to male non-human primates. This work comes from stem cell researchers at the University of Pittsburgh School of Medicine and the Magee-Womens Research Institute and was published in the journal Cell Stem Cell.

This is a remarkable finding because some men or boys must undergo cancer treatment before they have their families. Since cancer drugs destroy dividing cells and do not discriminate between normal cells and cancer cells, the stem cells that make sperm tend to take a serious beating during chemotherapy. The cancer might be destroyed, but the patient will be rendered sterile.

The senior investigator for this work, Kyle Orwig, associate professor in the Department of Obstetrics, Gynecology and Reproductive Medicine at the University of Pittsburgh School of Medicine said: “Men can bank sperm before they have cancer treatment if they hope to have biological children later in their lives,” he says. “But that is not an option for young boys who haven’t gone through puberty, can’t provide a sperm sample, and are many years away from thinking about having babies.”

Young boys that have yet to experience puberty do not yet make any sperm, but they have a modicum of spermatogonial stem cells in their testes that are waiting in the wings to produce sperm during puberty. During puberty, neurons in a part of the brain called the hypothalamus release a 10-amino acid peptide called “gonadotropin releasing hormone” (GnRH). Because these neurons release their GnRH into blood vessels that feed the pituitary gland, just below the hypothalamus, it flows directly to the pituitary.

GnRH stimulates the anterior lobe of the pituitary to release two trophic hormones: follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are collectively known as gonadotropins. FSH initiates sperm cell production in the tubules within the testes and LH stimulates the synthesis of the steroid hormone testosterone, which is necessary for sperm maturation.

Orwig and his colleagues wanted to determine if it is possible to restore fertility by freezing and banking these spermatogonial stem cells and then reintroducing them back into the testes after the completion of chemotherapy. Orwig and others took biopsies from the testes of young, adult male macaque monkeys that had yet to experience puberty. This tissue was cryopreserved in small samples. Then the monkeys were treated with chemotherapy agents that are known to reduce fertility.

A few months after chemotherapy treatment, Orwig and his colleagues transplanted each monkey’s own spermatogonial stem cells into their own testes by means of ultrasound-guided surgery. Nine of twelve adult animals showed restoration of sperm production and three of five very young animals that had not yet experienced puberty demonstrated an ability to make functional sperm after they reached maturity.

In a second experiment, spermatogonial stem cells from unrelated monkeys were transplanted into infertile animals. These transplanted cells generated sperm that had the DNA fingerprint of the donor. Because the testes contain a barrier to the immune system that prevents access of the sperm to the immune system, the implanted tissue could survive without being attacked by the immune system. This is a problem is males who have immune responses to sperm. For example, men who have had a vasectomy or make homosexuals have immune responses to human sperm. Laboratory tests showed that sperm from transplant recipients successfully fertilized 81 eggs that lead to embryos that developed normally. Donor parentage was confirmed in these embryos.

“This study demonstrates that spermatogonial stem cells from higher primates can be frozen and thawed without losing their activity, and that they can be transplanted to produce functional sperm that are able to fertilize eggs and give rise to early embryos,” Orwig says.

Several centers in the U.S. and elsewhere are already banking testicular tissue for young male cancer patients. This is in future anticipation that new stem cell-based therapies will be developed that will help them achieve pregnancy and have their own biological children. Thus this proof-of-principle experiment has generated no small degree of excitement for clinicians and patients who have compromised fertility.

According to Orwig, “These patients and their families are the pioneers that inspire our research and help drive the development of new medical breakthroughs.” He continued: “Many questions remain to be answered,” Orwig notes. “Should we re-introduce the spermatogonial cells as soon as treatment is over, or wait until the patient is considered cured of his disease, or when he is ready to start a family? How do we eliminate the risk of cancer recurrence if we give back untreated cells that might include cancer cells? These are issues we still must work through, but this study does show us the concept is feasible.”

http://beyondthedish.wordpress.com/author/mburatov/

Men Replaced: Killing Spiders Not Enough

In VICTORIES & SUCCESS STORIES on January 24, 2012 at 4:20 am
Researchers to build artificial testicles for infertile men
San Francisco – Researchers in California are working to build an artificial testicle, a human “sperm-making biological machine,” that can produce human sperm and allow otherwise infertile men to make babies.
According to My Health News Daily, Dr. Paul Turek, director of the Turek Clinic, a men’s health medical practice in San Francisco, says that recent advances show that the idea of treating infertility in male animals by producing sperm using stem cells is feasible. While this has been done successfully in mice, it has not been done in humans.
Turek recently announced on his Turek on Men’s Health site that he has received a government grant to develop a human “sperm-making biological machine.” According to My Health News Daily, Turek and his colleague, Dr. Constance John, chief executive of MandalMed Inc., a biotech company in San Francisco, received a small research grant from the National Institute of Environmental Health Sciences.
Turek says the new “machine” will not be designed to resemble a testicle like non-sperm-producing prosthesis that are saline-filled implant for men who don’t have testicles. Rather, the sperm producing machine will come as a cylindrical bag a few inches in length and will look “like a transparent, over-sized Tootsie Roll.”
Turek on Men’s Health explains: “To be clear, this grant is not about creating a testicular implant for a man who is missing a real one. We did that a decade or so ago. This award is to develop a sperm making biological machine…We now have a couple of years to create human artificial sperm in a dish, or more formally, a ‘bioreactor,’ a fancy dish to be sure.” …

Read more: http://www.digitaljournal.com/article/318149#ixzz1kHKdE2hL

Sperm Grown in a Dish – Technology Review

In VICTORIES & SUCCESS STORIES on March 24, 2011 at 9:46 am

Stem cells now capable of making sperm. – dg


Sperm Grown in a Dish

Researchers make sperm that successfully produces offspring in mice—a development that could one day help infertile men.

Savior sperm: Scientists in Japan have grown functional mouse sperm (shown here in green) in a dish by mimicking the chemical environment of the testes. The sperm is capable of producing fertile offspring.  – Credit: Takehiko Ogawa, Yokohama City University

In a significant step toward combating male infertility, researchers at Yokohama City University have grown mouse sperm in a dish and used the sperm to produce pups that were themselves fertile in adulthood.

Researchers started with small fragments of tissue containing sperm stem cells, called spermagonia, collected from the testes of baby mice. They then grew those cells into functional sperm, using various chemicals to simulate the natural environment of the testes. The results of the study, published in this week’s issue of Nature, may eventually benefit infertile men and boys undergoing chemotherapy.

http://inplacenews.files.wordpress.com/2008/04/sperm.jpg

Sperm Grown in a Dish – Technology Review.

Can Stem Cells Produce More Sperm

In VICTORIES & SUCCESS STORIES on September 14, 2009 at 6:18 pm

Stem cell injection for infertile men

An injection of stem cells could be a new treatment for male infertility. Research suggests that as many as one in three men has problems producing sperm.

In the trial, due to start this month in Jordan, bone marrow cells will be taken from men aged 20 to 50 and added to a solution similar to that found in the testes.

The mixture will then be injected into and around the tubes in the testes where sperm cells develop. The idea is that the stem cells will convert into those that help make sperm. Initial laboratory tests have found this to be the case.

Doctors will monitor the amount of sperm in semen samples taken over the following six months, and will also look at pregnancy rates after around one year.

via Health news: New schizophrenia drug, help for diabetics and stem cell injections for infertile men | Mail Online.

Sperm Stem Cell Expiration Date?

In ALL ARTICLES on August 26, 2009 at 2:04 pm

Do men have a best-before date when it comes to fathering kids? Ridiculous, most of us would answer. Just look at these celebrity old guys who became dads in their 50s, 60s, and beyond: Charlie Chaplin at 73; former prime minister Pierre Trudeau at 72, Pablo Picasso at 68; Larry King at 65; Warren Beatty at 63; and Dave Letterman at 56.

https://i2.wp.com/4.bp.blogspot.com/_3y3MF-4HXAM/SFowRAG3FfI/AAAAAAAAEN8/ABlsqfpkE94/s400/picasso-sylvette.jpg

“Women are born with a fixed number of oocytes,” says Dr. Bernard Robaire, describing the female germ cells crucial to reproduction. The McGill University researcher who is funded by the Canadian Institutes of Health Research (CIHR), says that men have no such limitation. Unlike women who, after the age of 35 find it more difficult to get pregnant, men produce 1,000 sperm a heartbeat–about 100 million sperm each day.

Theoretically speaking, then, men can go forth and multiply forever — or as long as their hearts beat. “The argument has always been that because men keep producing sperm that are fresh all the time it makes no difference whether you have sperm from an 85-year-old man or a 35-year-old man,” says Robaire.

However, there’s a growing body of research that suggests there may be limits to men’s fertility, too. Recent studies have shown that men over the age of 40 have a lower chance of producing children than their younger counterparts. And they have an elevated risk of having children with autism, bipolar disease and schizophrenia.

In addition to concerns about mental illness, some studies have also shown that children born to older fathers score lower on intelligence tests. One study found that the incidence of down syndrome was related to sperm approximately 50% of the time.

“What we found was that if you put old males with young females, the development of the says Robaire, explaining his work with lab only the quality of the sperm,” he stresses. So is there a biological clock for men? “Yes, because a biological clock doesn’t just refer to the number of sperm produced but also their quality.” Robaire adds that there are many older men who produce children who are normal in every way. Nonetheless, studies show that the best age for perfect sperm is under 40.

via Best before… – Northern News – Ontario, CA.

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