menopause
dr. dolittle | January 13, 2017 Image of an orca and her calf from Wikimedia Commons
Orcas are one of only three species of mammals that go through menopause, including humans of course. A new study published in Current Biology may have discovered why this happens in killer whales.
Examination of 43 years worth of data collected by the Center for Whale Research and Fisheries and Oceans Canada, revealed a remarkable finding about the costs of reproduction in orcas. Older mothers tend to spend more time taking care of the family, so to speak, by making sure her offspring know where or when to find food. While this…
oracknows | April 24, 2016Arguably, one of the most popular forms of so-called "complementary and alternative medicine" (CAM) being "integrated" with real medicine by those who label their specialty "integrative medicine" is acupuncture. It's particularly popular in academic medical centers as a subject of what I like to refer to as "quackademic medicine"; that is, the study of pseudoscience and quackery as though it were real medicine. Consider this. It's very difficult to find academic medical centers that will proclaim that they offer, for example, The One Quackery To Rule Them All (homeopathy). True, a lot of…
oracknows | April 13, 2016Of all the forms of quackery that have been “integrated” into medicine of late, arguably one of the most popular is acupuncture. It’s offered in fertility clinics. It’s offered in hospitals and medical clinics all over the place. The vast majority of academic medical centers that have embraced quackademic medicine offer acupuncture. (Quackademic medicine, for those not familiar with the term we reserve for the study of alternative medicine in academic medical centers that really should recognize it as quackery.) Hell, quite a few that haven’t embraced quackademic medicine offer acupuncture.…
oracknows | August 26, 2015It's always disappointing to see a good journal fall for bad medicine, particularly when it's in your field. For example, the Journal of Clinical Oncology (affectionately referred to by its abbreviation JCO) is the official journal of the American Society of Clinical Oncology (ASCO) and probably the most read clinical journal by those involved in the clinical care of cancer patients. Just as most oncologists, surgeons, and radiation oncologists who specialize in the care of cancer patients belong to ASCO, most of them also at least peruse JCO on a regular basis because major results of large…
razib | October 30, 2009I've discussed menopause as an adaptation and the grandmother effect before. I was also pleased to see the responses of Larry Moran's readers when he presented his standard anti-adaptationist line of argument. I don't want to retread familiar ground here, I'm not sure if menopause is an adaptation, but let's assume so for the purposes of reviewing a new paper which has come out and offers a slight but fascinating twist on the grandmother hypothesis. Grandma plays favourites: X-chromosome relatedness and sex-specific childhood mortality:
Biologists use genetic relatedness between family…
razib | October 12, 2009I've talked about menopause before. One question in evolutionary anthropology is whether it is an adaptation, a derived trait in our species which emerged due to the force of natural selection, or simply a physiological byproduct of some other phenomenon. The key point is the peculiar asymmetry in male and female reproductive potentials; males decline gradually over time, while the general suite of female reproductive function simply shuts down at during middle age. Eric Michael Johnson reviews a new paper by the redoubtable Virpi Lummaa, Fitness benefits of prolonged post-reproductive…
razib | May 18, 2009There are several papers and letters in Nature Genetics on the relationship between menarche, menopause, etc. and genetics.
Meta-analysis of genome-wide association data identifies two loci influencing age at menarche:
We conducted a meta-analysis of genome-wide association data to detect genes influencing age at menarche in 17,510 women. The strongest signal was at 9q31.2 (P = 1.7 10-9), where the nearest genes include TMEM38B, FKTN, FSD1L, TAL2 and ZNF462. The next best signal was near the LIN28B gene (rs7759938; P = 7.0 10-9), which also influences adult height. We provide the first…
edyong | April 1, 2008You could argue that life is all about cheating death and having enough sex to pass on your genes to the next generation, as many times as possible. From this dispassionate viewpoint, human reproduction is very perplexing for our reproductive potential has an early expiry date. At an average age of 38, women start becoming rapidly less fertile only to permanently lose the ability to have children some 10 years later during menopause.
From an evolutionary point of view, this decline is bizarre. Other long-lived animals stay fertile until close to the end of their lives, with elephants…
neurotopia | August 3, 2007The LA Times has an interesting story about a statement regarding the use of bisphenol A, a compound that has many uses in the plastics industry and also happens to have estrogenic effects.
The scientists -- including four from federal health agencies -- reviewed about 700 studies before concluding that people are exposed to levels of the chemical exceeding those that harm lab animals. Infants and fetuses are most vulnerable, they said.
This is an important point. Organisms in utero can be exquisitely sensitive to growth factors and hormones, sometimes hundreds or even thousands of times…
neurotopia | July 9, 2007I recently posted three "Basics"-style blurbs about menopause and hormone therapy (HT). If you missed it, they are here, here, and here. The field has gone through a lot of upheaval since the WHI studies in 2002, and I would just like to share my thoughts on how to approach where we stand now. These are the sorts of questions and considerations that researchers and health care professionals need to keep in mind when they evaluate HT. After the reference-heavy previous posts this one is going to just be my thoughts, and very off-the-cuff at that.
We, as humans, have a tendency to put…
neurotopia | July 5, 2007This is the third part in an overview of menopause and hormone therapy. Parts one and two are here and here. This time around I describe changes in cognitive and behavioral profiles for women and animal models of menopause. I may decide to expand on a handful of studies at a later date, but for now I wanted to provide a very brief overview of human studies, problems inherent to human studies, and animal studies. I think the next part of this series will focus on the quality of our animal models and what they have to tell us. But for now, anyone who is interested in these issues knows where…
neurotopia | July 4, 2007This is the second of a series that examines menopause, hormone therapy, and consequences of each. Today's installment looks at the makeup of common hormones on the market, physiological consequences of hormone loss and replacement, and the Women's Health Initiative (WHI) studies. A slight emphasis is placed on Alzheimer's Disease as a segway to the next installments, which will focus on cognitive and neurobiological consequences of menopause and hormone therapy.
Components of Common Hormone Therapies
17-beta estradiol (E2), the primary circulating estrogen during reproductive years, was…
neurotopia | June 13, 2007I thought I'd hop on the Basics bandwagon. Here's an oldy of mine with some menopause and hormone therapy background. WARNING: rampant pharmaceutical company sexism ahead. Do not attempt to communicate or reason with Zuska for at least 4 hours after reading. Rumor also has it that Tara is advocating for a beat-down.
Parts II and III are here and here.
The Transition to Menopause
Menopause is defined as the cessation of ovarian function. It occurs at the average age of 50 in women, is accompanied by a decrease in circulating levels of estrogen and progesterone associated with the loss of…
neurotopia | January 4, 2007The blog carnival Mendel's Garden got bumped because of the holiday. I've decided to post it this coming Monday, so I'm giving everyone until Sunday at 6pm EST to get their posts in!
neurotopia | June 9, 2006...you might not know what to do
you might have to think of
how you got started
sittin' in your little room
--The White Stripes
Welcome to the second incarnation of Neurotopia! The old incarnation can be found here, although lately it has just been a collection of posts where I complain about how Blogger stinks. But no more! Now I'm here on this slick new platform! The SEED overlords pulled a mean trick on me: they set up the new blog launch mere hours before I'm supposed to hit the road and celebrate my 8th anniversary by accompanying Mrs. Evil Monkey to Fallingwater for the weekend.…