Saturday, September 22, 2007
Friday, September 21, 2007
Do We Really Need To Use Immunosuppressant Therapy For Antiovarian Antibodies?
Over three decades ago researchers observed a high rate of premature ovarian failure associated with poly-endocrine autoimmune disease and suggested that there might be an autoimmune disease of the ovary. At about the same time IVF workers observed auto-antibodies to eggs in the ovary in women with infertility and also suggested there might be an autoimmune disease of the ovary. Since that time, the concept of ovarian autoimmune disease has become more widely recognized but significant advances in our understanding are only just beginning to occur.
Such antibodies would bind to important functional sites in the ovary and granulosa cells and impair the normal response. The anti-ovarian antibodies were found fairly recently, and their complete function is not well known yet. It is believed that these antibodies cause disturbances that are a cause of ovarian failure/non-ovulation or poor ovulation. They are believed also to be a cause of less-than-expected response to various medications to stimulate proper ovarian function, and possibly even formation of less-than-excellent and normal eggs. The treatment of this condition is more or less experimental. Very infrequently, this condition can be helped through in vitro fertilization and if everything else fails an egg donation from a fertile donor is the evidence based-medicine’s answer to this disorder. When such a pregnancy is properly supported by administration of exogenous hormones – progesterone and sometimes even estrogen – it has an excellent chance to lead to normal delivery.
Ovarian autoimmune disease is principally associated with Premature Ovarian Failure (POF) and with unexplained infertility. It is possible that autoimmune unexplained infertility is an early stage of autoimmune POF but this remains to be demonstrated conclusively. POF is the onset of menopause before age 40 and occurs in one to two percent, or about one to two million women. Like natural menopause around age 50, premature menopause is identified by cessation of menstrual cycles for one year, accompanied by elevated follicle stimulating hormone (FSH) and reduced estradiol levels in blood . While some cases of POF have a genetic cause (such as Turner syndrome), or are due to chemotherapy, recent studies suggest that about half the cases of premature menopause are due to an autoimmune attack on ovarian follicles and the eggs (oocytes).
There is still a lack of information on the specific features of autoimmune POF. Some women with POF may have a family history of POF but most do not. However, women with POF have a higher risk for other autoimmune endocrine diseases, such as thyroid disease, Addison disease, type 1 diabetes, and autoimmune poly-glandular syndromes.
Women with infertility and ovarian auto-antibodies tend to have lower than expected estradiol responses to gonadotropin hormone stimulation (i.e. poor responders) and lower pregnancy rates following infertility treatment. Poor responders with ovarian antibodies were younger than poor responders without ovarian antibodies. This suggests that although some poor responses are associated with early stages of the menopause progression and reduced number of functional follicles, others are associated with an autoimmune process.
Ovarian autoimmunity is identified by the presence of anti-ovarian antibodies. There are several different types of tests and consequently different names for these antibodies. Antibodies specifically to eggs and to the zona pellucida (an area surrounding the eggs), or to ovarian cells have been described (9). Some women have antibodies to both ovarian cells and to eggs and others have only one of these antibodies. Ovarian autoimmunity is not identified by traditional tests for ovarian function, such as elevated pituitary follicle stimulating hormone in POF. Although the cause may differ, the symptoms of autoimmune and non-autoimmune POF are the same as in a normal menopause, including hot flashes, dry vaginal tissues, painful sex, infertility, bone loss, and an increased risk of cardiovascular disease. Likewise, autoimmune infertility can only be distinguished from non-autoimmune infertility by specific antibody tests.
As with other endocrine disorders, POF is treated by replacing the lost hormone, in this case hormone replacement therapy (HRT) with estrogen and progesterone to protect the heart, bones, genital and urinary tract tissues, and the nervous system. However, if a woman with infertility or POF wants to become pregnant, treatment with hormones that stimulate ovarian follicles to grow and produce eggs can be tried. If hormone stimulation alone does not result in a pregnancy, women may be treated by more aggressive methods such as in vitro fertilization (IVF). There have been reports of success in combination with low dose immunosuppression. However, success rates are relatively low and there are concerns about the side effects of immunosuppressant therapy. We, at Rotunda do not believe in Immunosuppression with steroids. This sort of approach has not been helpful or useful for any patients in our experience. In some rare cases of POF, follicular function may spontaneously resume, and a pregnancy can occur.
The next significant advance in characterizing ovarian autoimmune disease will be identification of the specific ovarian proteins recognized by the auto antibodies. Once we have tests that detect specific auto-antigens, we will be moving closer to some evidence-based medicine answers. This will permit development of tests based on use of specific antigens, which will improve clinical diagnosis. An understanding of how these proteins become targets of an autoimmune attack would be a significant step toward designing therapies for reversing the effects of this disorder.
As of now, the only known treatment which gives results for this disorder is Donor Egg IVF.
Such antibodies would bind to important functional sites in the ovary and granulosa cells and impair the normal response. The anti-ovarian antibodies were found fairly recently, and their complete function is not well known yet. It is believed that these antibodies cause disturbances that are a cause of ovarian failure/non-ovulation or poor ovulation. They are believed also to be a cause of less-than-expected response to various medications to stimulate proper ovarian function, and possibly even formation of less-than-excellent and normal eggs. The treatment of this condition is more or less experimental. Very infrequently, this condition can be helped through in vitro fertilization and if everything else fails an egg donation from a fertile donor is the evidence based-medicine’s answer to this disorder. When such a pregnancy is properly supported by administration of exogenous hormones – progesterone and sometimes even estrogen – it has an excellent chance to lead to normal delivery.
Ovarian autoimmune disease is principally associated with Premature Ovarian Failure (POF) and with unexplained infertility. It is possible that autoimmune unexplained infertility is an early stage of autoimmune POF but this remains to be demonstrated conclusively. POF is the onset of menopause before age 40 and occurs in one to two percent, or about one to two million women. Like natural menopause around age 50, premature menopause is identified by cessation of menstrual cycles for one year, accompanied by elevated follicle stimulating hormone (FSH) and reduced estradiol levels in blood . While some cases of POF have a genetic cause (such as Turner syndrome), or are due to chemotherapy, recent studies suggest that about half the cases of premature menopause are due to an autoimmune attack on ovarian follicles and the eggs (oocytes).
There is still a lack of information on the specific features of autoimmune POF. Some women with POF may have a family history of POF but most do not. However, women with POF have a higher risk for other autoimmune endocrine diseases, such as thyroid disease, Addison disease, type 1 diabetes, and autoimmune poly-glandular syndromes.
Women with infertility and ovarian auto-antibodies tend to have lower than expected estradiol responses to gonadotropin hormone stimulation (i.e. poor responders) and lower pregnancy rates following infertility treatment. Poor responders with ovarian antibodies were younger than poor responders without ovarian antibodies. This suggests that although some poor responses are associated with early stages of the menopause progression and reduced number of functional follicles, others are associated with an autoimmune process.
Ovarian autoimmunity is identified by the presence of anti-ovarian antibodies. There are several different types of tests and consequently different names for these antibodies. Antibodies specifically to eggs and to the zona pellucida (an area surrounding the eggs), or to ovarian cells have been described (9). Some women have antibodies to both ovarian cells and to eggs and others have only one of these antibodies. Ovarian autoimmunity is not identified by traditional tests for ovarian function, such as elevated pituitary follicle stimulating hormone in POF. Although the cause may differ, the symptoms of autoimmune and non-autoimmune POF are the same as in a normal menopause, including hot flashes, dry vaginal tissues, painful sex, infertility, bone loss, and an increased risk of cardiovascular disease. Likewise, autoimmune infertility can only be distinguished from non-autoimmune infertility by specific antibody tests.
As with other endocrine disorders, POF is treated by replacing the lost hormone, in this case hormone replacement therapy (HRT) with estrogen and progesterone to protect the heart, bones, genital and urinary tract tissues, and the nervous system. However, if a woman with infertility or POF wants to become pregnant, treatment with hormones that stimulate ovarian follicles to grow and produce eggs can be tried. If hormone stimulation alone does not result in a pregnancy, women may be treated by more aggressive methods such as in vitro fertilization (IVF). There have been reports of success in combination with low dose immunosuppression. However, success rates are relatively low and there are concerns about the side effects of immunosuppressant therapy. We, at Rotunda do not believe in Immunosuppression with steroids. This sort of approach has not been helpful or useful for any patients in our experience. In some rare cases of POF, follicular function may spontaneously resume, and a pregnancy can occur.
The next significant advance in characterizing ovarian autoimmune disease will be identification of the specific ovarian proteins recognized by the auto antibodies. Once we have tests that detect specific auto-antigens, we will be moving closer to some evidence-based medicine answers. This will permit development of tests based on use of specific antigens, which will improve clinical diagnosis. An understanding of how these proteins become targets of an autoimmune attack would be a significant step toward designing therapies for reversing the effects of this disorder.
As of now, the only known treatment which gives results for this disorder is Donor Egg IVF.
Thursday, September 20, 2007
Is Co-culture The Magic Recipe For Improving IVF Implantation Rates?
Although I am writing about co-culture in IVF, we are not currently doing any co-culture. With recent improvements in IVF culture media and techniques, our IVF pregnancy rates (without co-culture) have improved dramatically. Therefore, we no longer see a need for co-culture. In vitro fertilization with co-culture has been utilized in animal in vitro embryo culture systems for over 30 years and more recently in some clinical human in vitro fertilization laboratories as well. The basic concept involves growing embryos in a culture medium on top of a proliferating monolayer of cells such as fallopian tube cells or cells from the lining of the uterus called endometrial cells. The idea is that these cells, which are sometimes referred to as "feeder" cells or "helper" cells, will stimulate development of the embryos by removing toxins from the medium, adding growth factors, or some other beneficial effect. Some studies have demonstrated improved pregnancy rates and delivery rates with utilization of co-culture for human in vitro fertilization.
Why don't all IVF centers use co-culture? There are several reasons that co-culture is not currently more widely used for human IVF:
1. Co-culture involves a lot of tedious work in the laboratory which leads to additional expense.
2. Most IVF labs are not experienced with culture of cells other than eggs, sperm, and embryos. Although culturing cells from the endometrium or fallopian tube is not extremely difficult, it does involve learning some new techniques.
3. There is no universal agreement that co-culture is necessary to provide optimal pregnancy rates from human in vitro fertilization.
4. Another issue is that depending on the source of cells used for the co-culture there may be concerns about transmission of infectious diseases such as viruses from the cell line to the developing embryos. To date there have been no reported cases of viral transmission to a human fetus. Non-autologous cell lines should be screened for infectious diseases prior to use in human embryo coculture.
Coculture is usually not applied universally to all cases in an IVF program. It is usually reserved for use in the "poor prognosis" patients. Studies have suggested that these patients can benefit the most from IVF with co-culture. Examples of poor prognosis patients include women over 40, women with previous IVF failures, women with elevated FSH (follicle stimulating hormone) levels, and women who respond poorly to ovarian stimulation with gonadotropins.
In general there are two schools of thought in this area. One school says that co-culture can be of a benefit for some patients undergoing in vitro fertilization. The philosophy here is that we do not need to know the exact mechanism of the benefit of co-culture, or exactly how standard in vitro culture systems are deficient - what we want is to help the couple get their baby. More like experienced hunches & claims rather than solid evidence based medicine. The other school says co-culture is a crutch that masks the real problem which is sub-optimal in vitro embryo culture systems. These people would prefer to use very pure and carefully defined media in order to maximize the culture environment. They believe that this can yield an equally high pregnancy rate without the use of co-culture. This is what we strongly believe in. I believe that the heart of an IVF clinic are good solid culture systems.
Clinical in vitro fertilization programs that are utilizing co-culture for their human IVF generally use one of three cell types. However, there are numerous other cell lines that have been successfully utilized as well. The cell lines most often used are fallopian tube cells which can be from either human or animal origin, endometrial cells from the lining of the uterus, or Vero cells which are from an immortalized cell line derived from African Green Monkey kidney cells. Cumulus cells from around the egg with or without granulosa cells from the walls of the ovarian follicles where the eggs develop can also be used for co-culture.
Most commonly the eggs and sperm are mixed together on the day of egg retrieval without the co-culture cells. The next morning, after identification of the fertilized eggs (called zygotes), these embryos are then transferred on to the co-culture cells which have been prepared several days in advance. The embryos are then cultured with the helper cells until the time of embryo transfer. This is usually two more days of culture.
Another potential application of co-culture for human in vitro fertilization programs is that of culturing embryos to the blastocyst stage and then performing blastocyst transfer. This allows selection of embryos that have been able to survive through the early cleavage stages of the first five days after fertilization. It is generally very difficult to get good numbers of high quality blastocysts when culturing in defined medium (no co-culture). This technique can allow transfer of fewer embryos while still maintaining an excellent pregnancy rate. For example, some programs have cultured embryos to blastocyst stage and had very good pregnancy rates resulting from transfer of only two blastocysts. This would greatly reduce the risk of high order multiple pregnancy that is seen in some programs transferring higher numbers of embryos.
Further research is needed in order to define exactly which patients would be benefited by co-culture. Also, the co-culture technique itself may be able to be further modified such that in vitro embryonic development is even better than what can be achieved with current technology. For example, many aspects of the co-culture technique could be altered, such as using a different cell line, a different medium, smaller droplets for culture, changing the medium more frequently, or other changes. By varying the usual co-culture techniques, we might obtain a further improvement in embryonic development over what is currently possible.
A practical problem with research in this area is that studies using variations on standard techniques are relatively easy to perform using animal embryos, but studies using human embryos are problematic to set up and implement. Results from co-culture studies done with animal embryos will not necessarily be applicable to IVF with human embryos.
Much has been learned about co-culture both for animal in vitro embryo culture and for in vitro culture in the human as well. Studies continue to attempt to discover exactly how co-culture improves embryonic development. If the cells make certain products that stimulate development of healthier embryos, these products might be able to be produced commercially and added to conventional culture media.
It is possible that pure and exactly defined chemical media might someday be so improved as compared to what is now in use that co-culture would not offer any increase in pregnancy rates, even for poor prognosis patients. However, we do not appear to be at that point today. Further co-culture research is needed before we make tall claims about this being a panacea & a potential Nobel prize winner.
Wednesday, September 19, 2007
Tuesday, September 18, 2007
The First Steps of an In-captivity born pre-term Panda
When the ancestors of human beings had only just learnt how to walk upright, the footprints of the Giant Panda were already all over East and South East Asia. But the peak population of the family of giant pandas has diminished greatly since then. Today, the total population of Pandas wavers at around one thousand, including some 100 animals in captivity. More seriously, in captivity few seem to have the natural desire to mate.
This year, a record number of 16 pandas have been born in captivity, according to China's Panda Breeding Programme. Because pandas in the wild number less than 1000, these sixteen babies are a significant addition to this endangered species population.This year the Wolong Chinese Giant Panda Protection Center has been successful in breeding two infants in total. It may seem like a small number, but around the world only 50 pandas are born every year and out of this number only 20 have a chance to grow up. Scientists are now investigating ways to get pandas bred in captivity back to where they belong - the wild. It is this that will complete the work of the researchers at the Wolong Chinese Panda Protection Center. Work which is ensuring the survival of the giant panda.
I recently came across these series of pictures of a pre-term Panda baby which would have made a baby-album proud! Pictures speak louder than a 1000 words & I will let you enjoy these from the pre-term delivery to 120 days of life...
Monday, September 17, 2007
Origins of Sex
A study cataloguing the different types of protein found in sperm for the first time could help to unveil some of the questions surrounding infertility and the origin of sex, scientists claim. Researchers from the University of Bath identified 381 proteins present in sperm of the fruit fly, Drosophila melanogaster. This finding is a 50-fold increase in the proteins previously identified.
Writing in the journal Nature Genetics, the researchers claim that their study is the first to characterise the whole-cell protein components of a higher eukaryotic cell (a cell in which all the genetic components are contained within a nucleus). These components (known as the proteome) contain everything the sperm needs to survive and function properly and provide the basis for studies investigating why some sperm are more successful than others. The findings could be significant for researching infertility in men as around half of the genes of the fruit fly sperm proteome have comparable versions in humans and mice. Proteins carry out an immense range of functions, from forming structural materials to catalysing chemical reactions, so knowing exactly what proteins are in sperm is a great step forward in understanding.
"This study offers a tantalising glimpse into how we might begin to answer some of biology's most fundamental questions," said Dr Tim Karr from the University of Bath, who led the study. "Amazingly we know very little about what is in a sperm, which probably explains why we don't really understand sex, let alone how it evolved." He added: "Before we catalogued the sperm proteome, we only knew a few specific proteins in the Drosophila sperm. Being able to compare the structure and content of the proteomes of sperm from different species should help us understand the evolution and origin of sperm."
Research published in Nature Genetics today describes 381 proteins present in sperm of the fruit fly, Drosophila melanogaster. Whilst more proteins may be identified as research progresses, this study marks the first substantial ’whole-cell’ characterisation of the protein components of a higher eukaryotic cell (a cell in which all the genetic components are contained within a nucleus).
By comparing the sperm proteome of the fruit fly with other species, scientists will also be able to rewind evolution and work out the core sperm proteome – the most basic constituents a sperm needs for sexual reproduction. This will shed light on how sex itself evolved.
Writing in the journal Nature Genetics, the researchers claim that their study is the first to characterise the whole-cell protein components of a higher eukaryotic cell (a cell in which all the genetic components are contained within a nucleus). These components (known as the proteome) contain everything the sperm needs to survive and function properly and provide the basis for studies investigating why some sperm are more successful than others. The findings could be significant for researching infertility in men as around half of the genes of the fruit fly sperm proteome have comparable versions in humans and mice. Proteins carry out an immense range of functions, from forming structural materials to catalysing chemical reactions, so knowing exactly what proteins are in sperm is a great step forward in understanding.
"This study offers a tantalising glimpse into how we might begin to answer some of biology's most fundamental questions," said Dr Tim Karr from the University of Bath, who led the study. "Amazingly we know very little about what is in a sperm, which probably explains why we don't really understand sex, let alone how it evolved." He added: "Before we catalogued the sperm proteome, we only knew a few specific proteins in the Drosophila sperm. Being able to compare the structure and content of the proteomes of sperm from different species should help us understand the evolution and origin of sperm."
Research published in Nature Genetics today describes 381 proteins present in sperm of the fruit fly, Drosophila melanogaster. Whilst more proteins may be identified as research progresses, this study marks the first substantial ’whole-cell’ characterisation of the protein components of a higher eukaryotic cell (a cell in which all the genetic components are contained within a nucleus).
By comparing the sperm proteome of the fruit fly with other species, scientists will also be able to rewind evolution and work out the core sperm proteome – the most basic constituents a sperm needs for sexual reproduction. This will shed light on how sex itself evolved.
Sunday, September 16, 2007
Angle Matters
Hi Friends,
Here are some super shots taken by amateur photographers.Hope to get some additions on the Blog!
Cheers & Have a Lazy Sunday!
Gautam
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