Posted by on December 3, 2015 - 1:25pm

Since the mid-19th century, researchers claimed they could identify the sex of an indivudual just by examining their disembodied brain. However, a new study out of Tel Aviv University disputes this. Indeed, all brians share characteristics, some more common in males, others more common in females, and other characteristics that are common in both of the sexes. While there are some general tendencies for each sex--for instance, men tend to have a larger amygdala--these differences are quite small and highly influenced by the environment. Essentially, throughout history, scientists have attempted to find the differences between male and female brains, when, in actuality, their similarieis are far greater in number.

In this new study, Dr. Daphnea Joel, a behavioral neuroscientist at Tel Aviv University, used existing sets of MRI brain images and measured the volumes of gray and white matter in over 1400 individuals. The research team also analyzed data collected from diffusion tensor imaging, which shows how white matter extends throughout the brain into different regions. The team found that instead of a clear-cut binary between male and female brains, there were large overlaps in the structures of each sex's brain. The researchers created a continuum of "femaleness" to "maleness" for the brain--indicating how some characteristics are more common in females vs. males and vice versa, but still leaves room for overlap. Take the hippocampus, for example. The left hippocampus is usually larger in men than in women, but the study indicated there were many female brains that had a larger or more male-typical left hippocampus and many males who had a hippocampus smaller than the average female. Therefore, this spectrum was needed to indicate the overlaps between sexes. The team reported that the majority of the brains were a mosaic of 'male' and 'female' structures. In fact, fewer than 8% of brains contained all male or all female structures; in other words, "There is no one type of male brain or female brain," Joel says.

Joel and her team also analyzed the propensity for assumed gender behavior and found that only 0.1% of subjects displayed only stereotypically-male or stereotypically-female behaviors, instead finding the vast majority of people to have mixed 'male' and 'female' behavioral characteristics. These findings paint an interesting picture, but there is still much more to learn. If male and female brains are so similar, they why are males five times as likely to develop autism or why are females twice as likely to suffer from depression? It's important to understand how these differences develop out of seemingly similar physiologies. 

Source: Brain & Behavior, DOI: 10.1126/science.aad7499

Posted by on June 1, 2015 - 9:20am

Scientists at Northwestern Medicine recently made an exciting discovery regarding why there is a higher prevalence rate for women than men in multiple sclerosis (MS) and other autoimmune diseases. They found that the innate lymphoid cell, which is a type of white blood cell, works differently in males versus females.

Most labs that study MS use female mice because they are much more likely than male mice to get the disease. Typically, two groups of female mice are used: one group of normal mice used as a control group and one group of mice with a genetic mutation in a growth factor receptor, which blocks the development of a subset of immune cells. However, a graduate student in the lab made an honest mistake and used two sets of male mice instead of female mice. At the end of the experiment, the male mice who had the mutation were extremely sick, which led to the realization that the mutation was acting differently in females and males.

The mice with the mutation were found to lack type 2 innate lymphoid cells, which are normally present in bone marrow, lymph nodes, and the thymus of both females and males. These cells are not found in the males with the mutation, which leads to a drastic change in the immune response of the mice and means that they are not protected against MS. In the normal male mice, these lymphoid cells were activated and protected the mice from the disease.

While female mice have the same lymphoid cells that male mice do, they do not become activated and therefore do no protect them from developing MS. This discovery in the lab has led to the current investigation into why these cells are activated more so in males than females and subsequently if it is possible to activate them in females in order to reduce their vulnerability to contracting MS.

Background on MS

Multiple sclerosis is a disease in which your immune system attacks your central nervous system, which is made up of your brain, optic nerves, and spinal cord. More specifically, the protective layer (myelin) that covers your nerves is attacked and subsequently damaged, disrupting the crucial communication between your brain and the rest of your body. The distortion and disturbance of nerve impulses traveling to and from the brain generate a wide variety of symptoms, depending on which nerves are affected and how damaged they become.



Northwestern Press Release

Original Publishes Findings in The Journal of Immunology

National Multiple Sclerosis Society

Mayo Clinic



Posted by on February 17, 2015 - 10:46am

When we think about sex differences in health, we do not normally think about our eyes.   While some clinical conditions are well known to affect the visual systems of men and women differentially, the sex-dependent effects on the visual system of other clinical conditions may be more subtle or more sporadic and hence less documented. Researchers are now discovering that sex differences exist in a wide range of eye disorders.  In some cases, the differences can be related to the hormone milieu.  In others, they are intertwined with other bodily systems such as neurotransmitter activity and blood flow. 

The visual system is especially amenable to assessment and examination because it has an organ-- the eye , that provides a "window" for interior inspection and study.     All these sex-dependent effects need to be better understood – from the front surface of the eye, to its interior, and to those parts of the visual system behind the eye.

A special issue of Current Eye Research includes a series of 12 review articles, solicited from experts in their respective fields, with most articles focused on different opthalmology subspecialtes. These articles collectively serve as a resource for eye care professionals as well as health care providers in other fields, especially those fields pertaining to women’s health.  In addition to helping improve care, the information in this special issue will provide timely foundations for future research projects reflecting the new NIH mandates that concern the inclusion of sex variables into preclinical studies.While this special issue centers on ophthalmic disorders, it aims to bridge existing specialties and it takes the view that women’s health concerns more than obstetrics and gynecology.

To learn more, visit:  Sex, Eyes, and Vision:   Male/female Distinctions in Opthalmic Disorders


Posted by on December 26, 2014 - 4:29pm

Chronic Obstructive Pulmonary Disease, the third leading cause of death in the U.S., was thought to primarily affect men.   But in recent years, the number of women with COPD has significantly increased and today more women than men die of COPD.  This increase was originally thought to be a latent effect due to the  increase in smoking in women in the 1060's but new research suggests that some other sex effects may be in play.

One of the challenges of uncovering sex differences is sometimes technology.  Today, a new technical, computerized method ---integrative network inference analysis--- is providing new insight into potential mechanisms for sex differences in COPD.  Scientists are able to chart different genetic patterns within likely networks for each sex using sputum and blood.   Using this technique, researchers at Harvard have identified functionally related sets of genes that are different in women and men with COPD.   These methods are beyond the scoop of this writer but the lesson here is that every day researchers are using more and more complex applications to better understand the impact of  biological sex on disease.

Sex difference exist in all body systems and the need to support sex inclusive research is critical.


Posted by on September 23, 2014 - 1:15pm

 National Institutes of Health has invested $10.1 million in supplemental funding to bolster the research of 82 grantees to explore the effects of sex in preclinical and clinical studies.

This investment encourages researchers to study females and males, and is a catalyst for considering sex as a fundamental variable in research. The current overreliance on male subjects in preclinical research can obscure key findings related to sex that could guide later human studies. This progressive approach will result in greater awareness of the need to study both sexes, demonstrate how research can incorporate sex, and reinforce the value of taking it into account as these studies yield results.

The Women's Health Research Institute has been actively supporting more sex equity in research not only at the human level but also in critical preclinical animal and cell research.  To read more about the NIH announcement, click HERE.

Posted by on August 28, 2014 - 10:41am

Melina Kibbe, MD  reported in a new study that surgical researchers rarely use female animals or cells in the published studies---despite a huge body of evidence showing that sex differences can play a critical role in medical research.  "Women make up half the population, but in surgical literature, 80 percent of the studies only include males," said Kibbe.  Published Aug. 28 in the journal Surgery, the study follows a "60 Minutes" segment aired in February that featured Dr. Kibbe and raised concerns that overlooking sex differences in biomedical research could lead to serious adverse effects.


As a result of Kibbe's article, editors of the five major surgical journals reviewed in Kibbe's publication will now require authors to state the sex of animals and cells used in their studies, and if both sexes are not included give the reasons why.

Dr. Kibbe, Professor of Surgical Research at Northwestern University Feinberg School of Medicine is member of the Women's Health Research Institute which is actively working on sex equity in research at the national level.   To read more:   CLICK HERE

Posted by on August 16, 2014 - 7:30am

Musculoskeletal health is one of the areas of medicine in which differences between males and females are most striking.   Although males have a higher incidence of traumatic injuries, females are disproportionately disabled by musculoskeletal conditions such as adolescent spinal deformities, ACL injuries, osteoarthritis, and osteoporotic fragility fractures. Therapeutic modalities have been based on studies of male populations or young adult male animals, or the studies do not specify the sex of the population. Understanding of these conditions as they occur throughout the human life span thus has been limited with respect to sex. Fostering research The American Academy of Orthopaedic Surgeons (AAOS) Women’s Health Issues Advisory Board (WHIAB) seeks to advocate, advance, and serve as a resource on sex and gender differences in musculoskeletal health and research. Since females suffer from disease in different ways than males, recognizing sex-related differences is critical to optimizing patient care. In an effort to foster the mission of the WHIAB, the Journal of Orthopaedics is featuring 10 articles which highlight research focused on sexual dimorphism in orthopaedics. Sexual dimorphism is considered a priority within the spectrum of orthopaedic research as demonstrated within these articles, including research in basic science, anatomy, biochemistry, hormonal, physiological, neuromuscular, and clinical form and function of bone and soft tissues.

Improved Healthcare Delivery

An approach tailored to the separate biologic needs of females and males through basic science and clinical research will enable healthcare providers to address each patient based on his or her individual biologic needs. Interventions, therapeutic modalities, and best future practices based on sexual dimorphism will improve healthcare delivery for all patients.

Sex-Related Differences in Neuromuscular Control: Implications for Injury Mechanisms or Healthy Stabilisation Strategies?
Teresa E. Flaxman, Andrew J. J. Smith, and Daniel L. Benoit

Effects of ACL reconstruction surgery on muscle activity of the lower limb during a jump-cut maneuver in males and females
Margaret S. Coats-Thomas, Daniel L. Miranda, Gary J. Badger and Braden C. Fleming

Knee rotation in healthy individuals related to age and gender
Per O. Almquist, Charlotte Ekdahl, Per-Erik Isberg and Thomas Fridén

Effect of Age and Gender on Cell Proliferation and Cell Surface Characterization of Synovial Fat Pad Derived Mesenchymal Stem Cells
Emma Fossett, Wasim S. Khan, Umile Giuseppe Longo, and Peter J. Smitham

Morphology of the Proximal Femur Differs Widely with Age and Sex: Relevance to Design and Selection of Femoral Prostheses
David S. Casper, Gregory K. Kim, Javad Parvizi, and Theresa A. Freeman

Gender and condylar differences in distal femur morphometry clarified by automated computer analyses
Kang Li, Evan Langdale, Scott Tashman, Christopher Harner and Xudong Zhang

Viscoelastic properties of human cortical bone tissue depend on gender and elastic modulus
Ziheng Wu, Timothy C. Ovaert and Glen L. Niebur

Gender Differences in Both Active and Passive Parts of the Plantar Flexors Series Elastic Component Stiffness and Geometrical Parameters of the Muscle-Tendon Complex
Alexandre Fouré , Christophe Cornu, Peter J. McNair, and Antoine Nordez

Age, sex, body anthropometry, and ACL size predict the structural properties of the human anterior cruciate ligament
Javad Hashemi, Hossein Mansouri, Naveen Chandrashekar, James R. Slauterbeck, Daniel M. Hardy and Bruce D. Beynnon

Gender differences in 3D morphology and bony impingement of human hips
Ichiro Nakahara, Masaki Takao, Takashi Sakai, Takashi Nishii, Hideki Yoshikawa and Nobuhiko Sugano

SOURCE:  Journal of Orthopaedic Research (JOR), in conjunction with the AAOS Women’s Health Issues Advisory Board, published a special virtual issue highlighting articles that focus on musculoskeletal sex differences.

Edited by: Laura M. Bruse Gehrig, MD, and the chairs the AAOS Women’s Health Issues Advisory Board.  It is available online at

Posted by on July 10, 2014 - 9:10am

Most people know that human clinical trials are critical to prove safety and efficacy in new medications.   This is also true for medical devices yet a recent study indicated that only 14% of device studies included sex as a key outcome measure, and only 4% included a subgroup analysis for female participants.    The differences in anatomy and physiology, as well as other factors in men and women,  can lead to devices working less effectively and safely.

The FDA's Office of Women's Health  recently supported a study of clinical trials conducted on cardiac resynchronization therapy (CRT), a pacemaker therapy for patients with heart failure.  Only 22% of the clinical trial participants were women.   By combining multiple studies and mining the multi-study data, the FDA Center for Devices and Radiological Health (CDRH) found that women benefited more than men from CRT.

This particular study demonstrates that we need adequate samples of men and women in studies early in the research process.   The good news is the FDA is taking two steps to insure more sex inclusion is built int0 future studies:

  • The FDA will finalized a guidance document that provides a clear framework for the inclusion of women in device studies
  • Mandated by Congress, the FDA will release an Action Plan, that will further address the analysis of data on women and product and safety data in labeling for drugs and devices.

How can you help??  Ask you doctor if there are clinical studies looking for subjects or contact your local medical school.    If you live in Illinois, you can join the Illinois Women's Health Registry  a gateway to clinical trials in Illinois.

Source:  FDA VOICE, June 23, 2014

Posted by on June 9, 2014 - 12:54pm

Dr. Teresa Woodruff and Dr. Melina Kibbe of the Women's Health Research Institute's Leadership Council were featured recently on WTTW Chicago Tonight. They discussed their activism for the inclusion of males and females in pre-clinical research studies. The recent shift by the NIH to include both genders in NIH-funded basic research, will help minimize gender biases in devises and medications once studies reach the clinical phase. Dr. Woodruff and Dr. Kibbe laud the NIH for this shift and also share their insights on this important issue. Watch the full WTTW interview today!