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by Dr. Susan Sarajari
Two studies presented at the 67th Annual Meeting of the American Society for Reproductive Medicine (ASRM) in Florida showed a possible link between semen parameters and diet.
The first study, conducted by a team of researchers from the Harvard School of Public Health, University of Rochester and University of Murcia in Spain, showed that sperm motility, but not morphology or concentration, was increased in those men who adhered to a diet high in intake of fish, vegetables and whole grains, as compared to those men who followed a diet with high intake of red meat and refined grains.The second study, done at the Fertility Center at Massachusetts General Hospital, showed that a high intake of trans fats was associated with a lower sperm concentration.
These studies indicate that there might be a link between a good diet and male fertility.
“Better Diet Equals Better Sperm”. 20-October, 2011. http//:www.medicalnews.com/articles/236316.php.
by Dr. Susan Daniel
An international team of scientists from the United States, Hong Kong, Taiwan, and England have identified the component of the outer shell (zona pellucida) of the egg that binds sperm. Using mass spectrometry the scientists found an abundance of a sugar chain known as sialyl-lewis-x sequence (SLeX). The scientists then performed experiments to see if sperm would stick to SLeX. Using a very small knife, they cut zonae from nonviable human eggs into two pieces. One piece was treated with a chemical that inactivates SLeX. The other piece served as a control and was not treated with anything. When sperm were added to the experiment, the scientists found that there were far less sperm bound to the treated zonae than to the untreated controls.
This work provides an exciting insight into the first steps involved in fertilization. It opens up new doors for the development of new types of contraceptives and the diagnosis and possibly the treatment of human infertility.
“How Sticky Egg Captures Sperm”. 22 Aug 2011. http://www.medicalnewstoday.com/releases/233038.php
by Dr. Susan Daniel
Scientists at Kyoto University in Japan have just announced that they have been able to use mouse embryonic stem cells to make primordial germ cells. When these cells were transplanted to the testes of sterile mice, normal sperm were produced. The sperm were then used to inseminate mouse eggs in the laboratory. The embryos were transferred to female mice who became pregnant and delivered healthy male and female pups. The pups were bred and have had litters of their own without the use of laboratory-grown sperm.
It has been suggested that this research might eventually be extended to the human male. It may be possible someday to take cells from an azoospermic man, reprogram them to develop into sperm cells, and restore fertility.
Kraft, S. “Male infertility may be cured by reprogramming skin cells”. 4 Aug 2011. http://www.medicalnewstoday.com/articles/232285.php
by Dr. Susan Sarajari
A study from the Nevada School of Medicine recently published in the British Journal of Pharmacology, elucidated some interesting facts regarding caffeine consumption and possibly decreased fertility.
The researchers at the University of Nevada studied fallopian tubes of mice and found that caffeine consumption stops the actions of specialized cells that coordinate fallopian tube contractions, which are necessary to move the egg along the fallopian tube. When these contractions are inhibited, eggs can not move along the tubes. These findings could potentially be extrapolated to humans and could provide a mechanism by which caffeine consumption could affect fertility and provide an explanation why high caffeine consumption can make it more difficult for a woman to conceive.
“Caffeine consumption and female infertility rates linked: Nevada School of Medicine Researcher”. 23-July, 2011. http//:www.medindia.net/news.
by Dr. Susan Daniel
Dr. Richard Zimmer at UCLA and Dr. Jeffrey Riffell at the University of Washington believe that their research into the interactions between egg and sperm in the red abalone might lead to improved treatments for infertility in humans. Red abalone are large sea snails that live in rocky areas on the ocean floor. When they spawn, the females release millions of eggs and the males discharge billions of sperm directly into the water. The scientists have found that the eggs release an amino acid called tryptophan that acts to help sperm to find and fertilize the eggs in the often turbulent ocean waters.
The same mechanism may be at work in the mammalian reproductive tract. Similar to the abalone, mammalian sperm must navigate through a fluid-filled environment to locate an egg. The fluid dynamics in an ocean environment are remarkably similar to those in the mammalian reproductive tract. To facilitate their interaction, eggs release an attractant for the sperm to follow.
Dr. Zimmer is confident that his research will make it possible to define the optimal environmental conditions in the mammalian reproductive system for contact between sperm and egg. New treatments may be developed in humans to enhance communication between the egg and sperm and modify fluid motion to make it easier for sperm to travel through the reproductive tract.
“Study of abalone yields new insights into sexual reproduction which could lead to techniques to improve fertilization in humans”. 7 Aug 2011. http://www.medicalnewstoday.com/releases/232333.php
by Dr. Susan Daniel
Using high-speed photography, scientists at the University of Cambridge, UK have discovered that the insides of mouse eggs pulse and vibrate after fertilization. They found that the speed and direction of the movements was highly predictive for the ability of an egg to develop into a viable embryo. Dr. Magdalena Zernicka-Goetz, one of the scientists working on the study believes that this is the fastest, easiest, and possibly the safest method available to determine whether a mouse egg has the potential to develop successfully.
The method has not been used on human eggs yet, but Dr. Zernicka-Goetz does not see why it should not work. She says that the insides of human eggs move in similar ways to mouse eggs. The scientists are hoping to be able to collaborate with an IVF clinic in the UK to determine if the method can be applied to the human. It could prove to be an invaluable tool to determine which embryos are viable and capable of resulting in pregnancy.
Weintraub, K. “Choosing the good eggs”. 09 Aug 2011. http://www.technologyreview.com/biomedicine/38259/
by Susan Sarajari
In a recent study, researchers at the University of California, San Francisco, examined in addition to acute ovarian failure, age-specific long-term effects of chemotherapy on women’s fertility, such as infertility and early menopause. The study included 620 women diagnosed with 5 specific cancers between the ages of 18-40 years old who were treated with chemotherapy.
The study found that chemotherapy narrows the window of fertility significantly even if a patient’s menstrual cycle returns. It was also noted that acute ovarian failure and incidence of infertility increased significantly with age at diagnosis of cancer. In addition, the probability of early menopause increased significantly with younger age at cancer diagnosis.
Focusing only on the resumption of the menstrual period after chemotherapy, will most likely not accurately predict a woman’s fertility potential after chemotherapy and more research studies are needed to better assess chemotherapy impact.
“Study shows greater impact of chemotherapy on fertility”. 25 August 2011.
http://www.medicalexpress.com.
by Dr. Susan Daniel
Scientists at UC Davis have discovered that up to 25% of men carry two copies of a defective gene known as DEFB126 which results in the production of abnormal β-defensin 126.
β-defensin 126 is a protein that is made in the epididymis of the male reproductive tract. It attaches to sperm and coats their surfaces to allow sperm to swim through the mucus in the female reproductive tract. The protein acts by protecting the sperm from attack by the woman’s immune system.
Men with abnormal β-defensin 126 generally have a normal semen analysis (sperm density, motility, progression, and morphology), but their sperm are unable to swim through the cervical mucus and up through the uterus and Fallopian tubes to fertilize eggs after ovulation. The scientists hope that they will be able to develop a simple test for the presence of the abnormal form of the protein so that couples having difficulty becoming pregnant can be directed to the best treatment option.
“Key to male infertility may be sperm coat protein”. 21 July 2011. http://www.medicalnewstoday.com/releases/231469.php
by Dr. Susan Sarajari
In a recent study led by researchers from the University of Michigan, data from 150,000 IVF cycles done at 361 different clinics was analyzed. Heavier women were noted to have an increased rate of cycle cancellation, decreased pregnancy rate and an increased risk of miscarriage as compared with normal weight women. Therefore, both fertility treatment cycle success and pregnancy outcome was affected. The reason for this is unclear but might be associated with extra estrogen that is released from adipose tissue. Weight is an important modifiable factor in IVF success and even a small decrease in weight can have significant effects on IVF outcome.
“Heavier women may have less IVF success”. 24 Aug 2011. Reuters Health. http//:www.reutersreprints.com.
by Dr. Susan Daniel
When you look at an early embryo in the lab, it is amazing to think that in a few short weeks this ball of cells will become an elongated embryo with distinct parts.
The first clues to explain how this dramatic change in shape occurs came from the work of Han Spemann and Hilde Mangold in 1924. They discovered that amphibian embryos contain an ‘organizer center’. When organizer cells from a newt tadpole were transplanted to another newt, they induced the cells in the area that they had been placed to form an embryonic structure that would not have formed otherwise. Spemann was awarded the Nobel Prize in 1935 for the discovery of organizers in early embryonic development.
Recently, scientists at the Hebrew University of Jerusalem reported that they have been able to generate human organizer cells from human embryonic stem cells. To show that these cells had organizer ability, they repeated Spemann and Mangold’s experiments using frog embryos. Amazingly, the human organizer cells induced the formation of a neural tube (a tissue that becomes the embryo’s central nervous system) composed of frog cells in the area into which the organizer cells had been injected.
“Hans Spemann – Biography”. 20 July 2011. http://nobelprize.org/nobel_prizes/medicine/laureates/1935/spemann-bio.html
“Scientists show for the first time how early human embryo acquires its shape”. 19 July 2011. http://medicalxpress.com/news/2011-07-scientists-early-human-embryo.html
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