biology

I have always said that I would be much more likely to sell my eggs for stem cell research than for use by infertile couples.  Since I want to have my own babies someday, the idea of half my DNA being out there in the world and me not being able to see what form it takes, weirds me out.  However, I wholeheartedly support stem cell research and find it incredibly fascinating.  And it doesn’t weird me out.  Would I let my eggs be used for stem cell research?  You betcha.  Would I let someone pay me $5000-$10000 for them?  Definitely.  Would I take the health risks and risks to my future personal fertility?  Unfortunately, no way..  I say unfortunately because now the formerly hypothetical is actually possible (but the health risks remain).  In an unprecedented move in the forward direction (and a break from what was considered national ethical consensus), the state of New York has approved payment for women donating their eggs to research.

From the statement released by the Empire State Stem Cell Board:

“On June 11, 2009, the Empire State Stem Cell Board (the “Board”) voted to allow funding of research on stem cell lines derived using eggs (called “oocytes”) donated solely for research purposes where the donor was, or will be, compensated for the expense, time, burden and discomfort associated with the donation process — within specified limits — as is currently permitted when women donate oocytes for reproductive purposes in New York State.”

The statement later adds:

“There is no principled reason to distinguish between donation of oocytes for reproductive purposes and research purposes when determining the ethicality of reimbursement.  The risks associated with donating oocytes to stem cell research are no greater than those associated with reproductive donations.  Moreover, donating oocytes to stem cell research arguably confers a greater benefit to society than does oocyte donation for private reproductive use.”

And:

“Similarly, there is no ethical basis for promulgating different payment policies for women who donate oocytes to stem cell research and from participants in other types of human subjects research.  National and international consensus bodies, as well as ethics scholars, generally have found it acceptable to provide reasonable compensation to subjects who participate in human subjects research to remunerate for the time and discomfort associated with participation in such research. To treat differently women who donate oocytes to stem cell research would be unjust, and would demean the significant contribution that oocyte donors make to society by participating in stem cell research.”

To donate one’s eggs, a woman has to inject hormones into her own abdomen for weeks, in order to stimulate the ovaries to release a large quantity of eggs at once.  This and the retrieval process can cause minor complications such as mood swings and swelling and bruising at injections sites, to major complications such as structural damage to reproductive organs or decreased fertility.  However, for some women who aren’t worried about being fertile, need the cash, and/or are feeling especially altruistic, it might be a good option.

I’m thankfully able to support myself on a meager graduate fellowship at the moment, so although I wish I could contribute to stem cell research somehow, I’ll hold on to my fertility and extra ooooooooooocytes for now!

I keep a close eye on the daily science headlines from a variety of sources, and one topic that I never stop seeing new news on is breastfeeding - and its benefits to both child and mother.  Just a few in the last year, I believe, will illustrate enough.

Benefits to Child:

NY Times article covering a large-scale study (over 15,000 participants) that found that at 6.5 years of age, the breastfed children scored significantly higher on vocabulary, word matching and verbal I.Q. tests compared to formula-fed children.  Additionally, teacher ratings were consistently higher for the breastfed children.

Breastfeeding transfers immunity to babies through antibodies made from the mother, and researchers are beginning to figure out the mechanism.  This transference of antibodies is why breastfed babies have much lower incidences of GI infections compared to formula-fed babies.

Benefits for Mother:

NY Times article covering a study that found breastfeeding reduces the risk of rheumatoid arthritis in the mother.  Women who breastfed up to a year decreased their risk by 25% and women who breastfed for over a year reduced their risk by 50%!

Breastfeeding for 6 months or more has also been associated with a lower risk of certain types of breast cancer - luminal cancer as well as triple-negative cancer, which is very aggressive and particularly difficult to treat.  Another research group is suggesting that lactation-based therapies could provide a component to a natural, non-toxic, anti-cancer therapy.

WHY then, may I ask did a recent study find that 94% of the nearly 1300 hospitals surveyed in east coast states from Maine to Mississippi are distributing formula samples to new mothers, even though multiple studies have shown that hospital-based distribution of formula samples is associated with reduction in exclusive breastfeeding rates, and opposition to this has been voiced by The American Academy of Pediatrics, World Health Organization, Centers for Disease Control and Prevention, and The American College of Obstetricians and Gynecologists??

Effluent from a wastewater treatment plant in Montreal was found to contain:

(measured in nanograms of hormone per liter of water)

90ng/L Estradiol - a natural estrogen, prescribed for HRT (Hormone Replacement Therapy)

53ng/L Norethindrone - used in BCPs (Birth Control Pills), HRT, and menstruation regulation

30ng/L Levonorgestrel - used in BCPs and morning after pills

The latter two are synthetic progestagens, compounds which mimic progesterone.  Human and animal excretion is considered the primary source of natural and synthetic estrogens and progestagens found in aquatic ecosystems.  Some of these hormones have been shown to reach our drinking water as well.  These hormone levels are sufficient enough to have endocrine-disrupting effects in wild aquatic ecosystems, which are receiving the effluent.  In some fish, exposure to as little as 1ng/L of a hormone can result in hermaphroditism, feminization and decreased fertility.  The numbers found in the Montreal effluent were between 30 and 90 times that amount!  Pretty scary.

Study Reference: Viglino L., K. Aboulfadl, M. Prevost, S. Sauve. 2008. Analysis of natural and synthetic endocrine disruptors in environmental waters using online preconcentration coupled with LC-APPI-MS/MS. Talanta 76: 1088-1096.

I’ve been preoccupied with finishing up the very last of my coursework.. so I haven’t been blogging for a while, despite all the interesting articles I’ve come across, not to mention the running list of reproduction-related topics that I’ve been wanting to research and communicate on, in this form. Now the semester is over and I’m sitting in Philadelphia waiting for my sister, and only sibling, to go into labor for the first time. In other words, I will be a first-time aunt! I’ll be the doula of course. Stay tuned for blog entries about the imminent experience..

In other news, a friend forwarded me some information a month or so ago about a really interesting situation in southwestern Nigeria. In the town of Igbo-Ora, population 60,000, a local elder asserts that there is hardly a family without a set of twins or triplets. Some parents in the town even have several sets of twins! According to population experts, Nigeria as a country has one of the highest rates of multiple births, but this particular part of the country seems to be particularly populated with high numbers of multiples.

No one seems to really be quite sure why this is. Some have suggested that it is perhaps a genetic predisposition that accounts for this strange phenomenon. Most interestingly, is the diet-related hypothesis. The Igbo-Ora population consumes a local yam, called agida (Dioscorea, I imagine) in high quantities, utilizing it as a staple food. Yams contain compounds which mimic human estrogens. This was demonstrated for the first time this year by Cheng et al., who found estrogenic activity in all 7 species/varieties of Dioscorea they screened.

It’s interesting to review and compile all these different articles related to the effects of estrogen or lack of estrogen on the human body. It is related to my doctoral work and helps me to have a greater understanding of hormonal regulation of various physiological functions. For instance, one example currently very relevant is my sister’s pregnancy. She has experienced fertility issues for the last several years. In the spring, after I had been reading extensively on female hormones and health for months to prepare for writing grant proposals and beginning my research, I noticed that she had been displaying signs of estrogen deficiency. I suggested that she begin taking a mixed phytoestrogen supplement, and a month later she was pregnant! Now 9 months later, here we are this moment trying to determine if her contractions are indicative of the onset of true labor or if bebe needs a few more days before she’s ready.

Image credit: AFP

Estrogenic yam study reference: Cheng, Wei-Yi, Yueh-Hsiung Kuo and Ching-Jang Huang. 2007. Isolation and Identification of Novel Estrogenic Compounds in Yam Tuber (Dioscorea alata Cv. Tainung No. 2). J. Agric. Food Chem. 55: 7350-7358.

For the first time, scientists have succesfully gotten a surrogate animal to produce offspring of another species. Masu salmon parents conceived babies that were 100% rainbow trout. Previous attempts using fertile salmon were far less successful. This time around, however, as reported in the September 14th issue of Science, Okutsu et al. used salmon, which were sterile and unable to produce their own egg and sperm. The sterile salmon were triploid, meaning they had 3 sets of chromosomes in their cells. Humans, and most other animals are diploid, meaning we have 2 sets of chromosomes. Human gametes (eggs and sperm) contain just 1 set, then the egg and sperm combine completing the double set that codes for the new organism made of half mom and half dad. However, if you have a triploid organism, the 3 sets cannot equally divide in half to create viable sperm or egg, so these individuals are sterile, with rare exceptions.

In this study, germ cells that are the progenitors of sperm and eggs were harvested from trout and implanted into young salmon embryos. The salmon grew and developed viable rainbow trout sperm and eggs exclusively. When combined through artificial insemination, the surrogate female salmon produced offspring which were fully trout. Although salmon and trout are not endangered, many species closely related to them are. This successful innovative use of surrogates provides a technique for increasing population numbers of genetically true individuals of endangered fish species. Masu salmon reproduce more quickly than the trout do, so if the trout for example did become endangered, this technique would allow baby trout to be produced more quickly than nature would normally allow. And the technology is not specific to salmon and trout, suggesting that it could applied to other species as well… at least other fish species, it appears. Pretty neat.