With generous support from Pfizer Pharmaceuticals and private donors, The Goddess Fund has awarded five grants to promising young scholars. Our scholars are redefining stroke research: see for yourself by reading about their results. Simply click on the links below to read each scholar's research report and summary.
The Goal of the Study
Preeclampsia is a complication of pregnancy that involves high blood pressure and a risk of stroke, both during and well after delivery — even up to 30 years later. The reasons for the risk of stroke are thought to be related to abnormal blood vessel opening and closing in the brain in response to stress, otherwise known as endothelial dysfunction. This blood vessel function can also be abnormal in people with high blood pressure (hypertension), and women with preeclampsia are four times as likely to have hypertension as women with normal pregnancies.
Therefore, the goal of the study is to measure the response of blood vessels in the brain to stress (vasomotor reactivity) in women with recent severe preeclampsia (severe high blood pressure during pregnancy) compared to women with normal pregnancies (normal blood pressure). We also measured biomarkers in the blood that may be related to preeclampsia, stroke, and/or vascular disease.
This pilot study uses a case-control design. Cases (women with severe preeclampsia) were compared with an equal number of controls (women with normal pregnancies) and matched based on maternal age, race-ethnicity, month of delivery, and number of pregnancies.
Women were identified at the time of delivery with having preeclampsia and were invited to participate. They were scheduled to return 6 weeks or more after delivery for the study testing.
We used ultrasound to measure blood vessel response in the brain (vasomotor reactivity) to breathing 5% carbon dioxide, which normally causes an increase in blood flow. An abnormal response is a blood flow increase of only 30% or less. We also collected blood for biomarkers on the same day.
Enrollment Summary: Enrollment for this study was from early February 2010 through September 2013. A total of 36 participants signed consent, 24 cases and 12 controls. However, only 8 of the cases could be contacted or were able to complete the study tests. The neurology coordinator made multiple attempts to reach these women, and this issue was the major stumbling block for completion of the study enrollment target. Some of these women were very young, single mothers, and faced difficult issues with child support, transportation, and employment (if employed in the first place). When it was time to complete the study, they either could not be reached, or they were scheduled and then did not show for the appointment. The final year of enrollment was focused on enrolling controls to match these 8 cases. We were only able to find controls for 7 of the cases, therefore the majority of the analyses were performed on 14 subjects.
The cases and controls were well-matched by race-ethnicity and age, as well as number of pregnancies (parity). The cases had a shorter duration of pregnancy (gestational age), as might be expected in the setting of severe preeclampsia, which often leads to premature delivery.
Clinical characteristics of the cases: One case had postpartum eclampsia (preeclampsia plus seizures) and severe hypertension, 2 small brain hemorrhages, and seizures occurring suddenly 12 days after delivery. Another case had a history of preeclampsia with her first pregnancy and was found to have Factor V Leiden mutation, which leads to blood clots. She was enrolled after she was diagnosed with preeclampsia during her second pregnancy. One case had sickle cell trait. There were no other women with stroke or brain blood vessel abnormalities diagnosed with imaging among the cases.
There was no difference in the vasomotor reactivity between cases and controls, but the small sample and wide variability in the results made it difficult to detect any differences between the two groups.
Interestingly, there was a strikingly significant difference in the levels of glycogen phosphorylase in cases vs. controls. In fact, 6 of the 7 control samples were below the level of detection of the assay, yet all of the cases had levels nearly 10 times higher or more than controls. To explore these biomarker results further, we looked for a marker of severity of preeclampsia, namely the admission blood pressure. It appears that the higher the initial blood pressure, the higher the levels of glycogen phosphorylase.
Conclusions: In this small case-control pilot study of severe preeclampsia vs women with normal pregnancy, there were no differences in vasomotor reactivity. However, we found evidence of a biomarker that was significantly higher in cases. Glycogen phosphorylase is an enzyme that has been associated with preeclampsia, particularly the BB (brain) subtype. In addition, expression this enzyme has been shown to be increased in the placentas of women with preeclampsia.1 The novel finding in the women in our study is that glycogen phosphorylase levels were still elevated many weeks to years after pregnancy, whereas the other studies were done only during pregnancy. Glycogen phosphorylase appears to be a measure of vascular stress, based on increased levels in patients with acute heart attacks,2 and this enzyme may be important in the hours after stroke symptoms start, as well.3 Our results suggest that women with a history of severe preeclampsia may show signs of vascular stress well after delivery. Multiple questions arise from these pilot data, such as whether glycogen phosphorylase is specific to preeclampsia or just the increased blood pressure, whether it is related to the lack of oxygen in placenta,1 or whether women with elevated levels of this enzyme are at risk for future stroke or heart attack, and when that risk is increased. More research is clearly needed to answer these questions.
The over-arching goal of this work was to better understand the persistent signs of vascular stress that could be related to future stroke risk in women who had recent severe preeclampsia. With these preliminary results, we can plan additional studies to confirm whether glycogen phosphorylase is a marker of future stroke risk in women with preeclampsia.
Plans for the Next Year: These pilot study results will be summarized and submitted for publication in a peer-reviewed journal. Any publications resulting from this study will acknowledge the Hazel K Goddess Fund for Research on Stroke in Women.
- Lippi G, Mattiuzzi C, Comelli I, Cervellin G. Glycogen phosphorylase isoenzyme BB in the diagnosis of acute myocardial infarction: a meta-analysis. Biochem. Medica. 2013;23:78–82.
- Tang Y, Lu A, Du X, Ran R, Xu H, Reilly M, Pancioli A, Khoury J, Sauerbeck L, Carrozzella J, Spilker J, Clark J, Wagner K, Jauch E, Verro P, Chang D, Broderick J, Sharp F. Gene expression in blood changes rapidly in neutrophils and monocytes after ischemic stroke in humans: a microarray study. J. Cereb. Blood Flow Metab. 2006;26:1089–1102.
- Tsoi SCM, Cale JM, Bird IM, Kay HH. cDNA microarray analysis of gene expression profiles in human placenta: up-regulation of the transcript encoding muscle subunit of glycogen phosphorylase in preeclampsia. J. Soc. Gynecol. Investig. 2003;10:496–502.
Estrogen-Mediated Neuroprotective Gene Expression in Brain
These studies have increased the understanding of the effects of hormone replacement therapy on the brain and their implications for stroke injury prevention and treatment. The goal was to identify genes expressed in the brain after stroke that are specifically modulated by estrogen. This informationis being used to understand the role of genes in mediating the effects of estrogen in stroke, with the ultimate goal of targeting specific genes as a novel strategy to modulate stroke risk and outcome.
The Beauty Shop Education Project: Educating African-American Women About Stroke
This study targeted the stroke education of African-American women by performing an educational intervention project in beauty parlors in Cincinnati, Ohio and Atlanta, Georgia. Beauticians that serve mostly African-American women were taught about stroke, including an easy-to-remember mnemonic for stroke warning signs. Beauticians now educate their clients regarding stroke, and hand out educational materials. Women who participated were tested on their knowledge of stroke at six weeks and four months to identify sustained increases in knowledge.
Healthcare Utilization, Costs and Outcomes of Older Women with Stroke
This effort analyzed the gender gap in healthcare utilization patterns, costs, and outcomes of stroke. A particular emphasis was placed on understanding why revascularization procedures, a preventative step, are applied differently and have different outcomes in women. The study tracked Medicare data longitudinally to:
- Provide best estimates of long-term outcome following stroke in women;
- Inform planning for current stroke prevention therapies;
- Identify new opportunities for stroke prevention, and
- Provide data for influencing health policy related to stroke in women
Estrogen and Neurogenesis: Understanding Functional Recovery After Stroke
This study will analyze the effect of estrogen on the brain after stroke. The primary goal of this study is to evaluate the mechanisms by which estrogen enhances cell regeneration or proliferation in the brain after stroke, a process known as neurogenesis. This study will also determine if hormonal status impacts long-term behavioral recovery after injury. This research will lead to an improved understanding of stroke-induced neurogenesis, with the hope that this process can be enhanced and lead to improved recovery after stroke.
Research Summary: Repair and Regrowth of Brain Cells With Estrogen
Dr. Louise McCullough received a Goddess Fund Career Development Grant in 2002. From 2002 to 2004, Dr. McCullough studied the effects of the female hormone estrogen on the development and repair of brain cells in mice. Previous research by Dr. McCullough and others had shown that female animals suffer less damage from stroke than male animals. It was unclear, however, whether estrogen aided the healing process after a stroke, and whether estrogen could be of use in males as well. Understanding the relationship between estrogen, brain cell repair, and gender has significant implications for the rehabilitation of stroke patients in the future.
Dr. McCullough studied both the behavior, and later the brains, of male and female mice after ischemic strokes. Focusing on damage and recovery at the cellular level, Dr. McCullough has made several discoveries that have far-reaching significance. Some of the highlights of Dr. McCullough's research are:
- Stroke leads to cell death among males and cell survival among females at the cellular level as well as in intact animals: gender differences may exist at the cellular level, meaning that female brain cells react differently than male brain cells during a stroke.
- Estrogen significantly improves the growth of new neurons in stroke-damaged brains, regardless of gender: estrogen may improve and hasten recovery after a stroke in both females and males.
- Females with reduced estrogen levels had greater damage to brain cells than those with normal estrogen levels: estrogen protects brain cells and may reduce brain damage as a result of stroke.
Additionally, this Career Development Award has led to 9 published articles, 2 chapters in press, as well as 5 additional articles that are currently in preparation. Dr. McCullough has been invited to give several talks on the subject of gender and stroke, and has been actively involved in the "Stop Stroke" campaign in Maryland. In addition, she has obtained grant funding from the American Heart Association until 2007.
Carotid Artery Properties, Stroke Risk & Mortality in Multi-Ethnic Women
This study potentially increased the ability to predict stroke among postmenopausal women and may ultimately lead to new ethnic-specific interventions to prevent cerebrovascular disease. The research assessed the association of specific carotid artery wall properties and carotid plaque with menopausal status and risk of stroke, myocardial infarction and mortality in an ethnically diverse population. A primary goal was to determine whether the progression of subclinical atherosclerosis in the carotid artery is influenced by age at menstruation, years since menopause and hormone replacement therapy, independent of conventional risk factors.
Research Summary: Using Ultrasound to Identify Stroke Risk
When Dr. Tanja Rundek was Columbia University Assistant Professor, she received a Goddess Fund Career Development Grant in 2001. During the subsequent three years, Dr. Rundek had been using ultrasound - a form of sonar best known for its use in obstetrics - to study the build up of plaque in the carotid arteries of the neck. Hardening of artery walls due to plaque buildup, a condition known as atherosclerosis, is a common cause of stroke. Unfortunately, people with atherosclerosis generally do not manifest symptoms until the condition is considerably advanced. If caught early enough, however, atherosclerosis can be treated and the risk for a later stroke greatly reduced.
Through ultrasound analysis of carotid arteries, Dr. Rundek sought to identify atherosclerosis among women from diverse racial and ethnic backgrounds before symptoms developed. Her work established a promising foundation for exciting new research in the use of ultrasound in stroke prevention. Among her results, Dr. Rundek found that:
- The carotid arteries of postmenopausal women are smaller and have stiffer walls: postmenopausal women may have a greater risk of stroke than men of similar age.
- There is a significant association between the metabolic syndrome (obesity, high cholesterol, high insulin, high blood pressure, and high triglycerides) and thickened carotid arteries: women with the metabolic syndrome may be at greater risk of developing atherosclerosis, and thus be at greater risk for stroke.
- Carotid ultrasound can be used for early identification of atherosclerosis: carotid ultrasound is a promising technique for identifying individuals with higher stroke risk.
These data have been of enormous scientific interest and have generated hypotheses for future research. As a result of her Career Development Grant research, Dr. Rundek has been lead author on 15 papers and abstracts, and has presented her results at 12 different research conferences worldwide. She has also received the prestigious Gilbert Baum Memorial Grant for promotion of ultrasound in medicine from the American Institute of Ultrasound in Medicine. Finally, Dr. Rundek has received three subsequent research grants to test the hypotheses generated from her Career Development Grant research.