I’m not bipolar, my mother had my blood tested.

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Carrie Mathison – Monique Nazareth

Assessing mood is inherently subjective.
“I’m sad.”
– “How sad are you?”
“Very sad.”
– “. . .”
However, scientifically quantifiable means of determining the severity of mood disorders are on the rise. Through the cooperation of researchers of the United States, Europe, and Australia spanning from the University of Texas to Deakin University, a blood compound (BDNF) was identified as an indicator of bipolar mood swings.

Brain-derived neurotrophic factor (BDNF) is a protein that aids in the development and survival of neurons. BDNF works to promote growth of neurons and synapses in the brain, eyes, and kidneys among other places. This protein has important links to obesity, epilepsy, schizophrenia, and as seen in this study, bipolar disorder.

Bipolar disorder causes intense emotionally states (overly happy or extreme hopelessness) that last for unusually long periods of time. In a state of mania, one might be easily distracted, sleep very little, overestimate their personal abilities, and act impulsively on high risk high pleasure activities. During a depressive episode the person might feel tired, lack concentration, drastically change eating habits, and actively think of death or suicide.

The researchers of this study analyzed the data of 52 studies published from 2005 to 2015 that looked at levels BDNF circulating within 3,339 individuals in manic, depressive, or euthymic (moderately happy) states compared to 3,142 healthy control participants. The goal was to find a link between amount of BDNF in the blood and current manic or depressed signs. The meta-analysis showed BDNF levels significantly dropped during manic and depressed episodes (Hedges’ g = -0.57 and -0.93 respectively), while euthymia showed no change in BDNF.

Not only did BDNF decrease more with increasing severity of bipolar episode, but individuals treated for their manic episodes showed increases in BDNF with medication. The BDNF increase was not seen with depressive episode treatment, but this could be due to depression signs persisting through treatment (Read as: science is good at depressing people, but bad at cheering them up).

If further research finds that BDNF levels are decreasing before depressive or manic episodes, this protein could be used as a forecaster of bipolar mood jumps. BDNF currently shows the most promise as a biomarker for activity.

In conjunction with other blood assays, BDNF may be able to help determine if in fact someone is bipolar, how severe their mood swings are, and give a more numeric answer to “how sad are you?”.

Reference:
Brisa S. Fernandes, Marc L. Molendijk, Cristiano A. Köhler, Jair C. Soares, Cláudio Manuel G. S. Leite, Rodrigo Machado-Vieira, Thamara L. Ribeiro, Jéssica C. Silva, Paulo M. G. Sales, João Quevedo, Viola Oertel-Knöchel, Eduard Vieta, Ana González-Pinto, Michael Berkand, André F. Carvalho. Peripheral brain-derived neurotrophic factor (BDNF) as a biomarker in bipolar disorder: a meta-analysis of 52 studies. BioMed Central Medicine, 2015.
DOI: 10.1186/s12916-015-0529-7

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Love and Biology

From Ihle, Kempenaers, and Forstmeier

From Ihle, Kempenaers, and Forstmeier

If two people marry each other to mutually benefit each other’s rise to the top of the political ladder or because their combined wealth will give their child a worry free life, what’s love got to do with it? If a man married his wife because his mother arranged it, would that affect the affection he showed towards their son? Researchers of the German Max Planck Institute for Ornithology studied zebra finches to find out if being able to freely choose one’s mate, ensured reproductive success.

The zebra finch is a monogamous species of bird that tends to stay with its chosen mate for life. With only one mate, however, the rate at which baby finches can be produced is limited. With the goal of creating offspring that will continue to pass down genes, many organisms including lions, deer, and crickets choose the polyandrous route and mate with numerous partners. The married zebra finch is not at a disadvantage, however. Fitness is a means of gauging success in passing on genes. This study found the relative fitness of finch pairs that chose their mate and compared it to those whose mate was chosen for them.

160 zebra finches freely chose a partner of the opposite sex. Following, half of the pairs were assigned to a random partner instead of their chosen one. Two more rounds of either allowing pairs to stay together or force choosing a partner for them followed this. After each pairing cycle, the couples were allowed to court and mate (get to know each other and have sex). Either good parenting or good genes would be the factor to determine if the group of finches choosing their own mate or the group with their mate chosen for them as having more fitness.

The study found the pairs of finches whom chose their own partners (C) were 37% more reproductively fit than pairs with mates force chosen for them (F). Many factors played into this:

– (C) vs. (F)
– Divorce rate: 8% vs. 24%
– Disappeared or buried eggs: 12% vs. 19%
– Offspring mortality: 32% vs. 52%
– Male courting outside his pair: Once every five hours vs. once every three hours

The higher fitness of zebra finch pairs that chose their own mates (C) supports the behavioral compatibility model. The finch pairs may have chosen each other based on harmony in parenting or general behavior according to the study. The downfalls seen within the (F) pairs were lower nest attendance by males, reduced motivation to care for young, chronic stress with a forced mate, lower female responsiveness, and higher male cheating rates with compatibility not increasing as marriages lengthened.

Is love the ultimate motivator for ensuring family success? Studies with people follow similar conclusions to this study in that emotionally satisfying relationships showed more commitment and less domestic violence. Lions can have their harem. I for one am a proponent of love (and so is science it seems).

Reference:
Malika Ihle, Bart Kempenaers, Wolfgang Forstmeier. Fitness Benefits of Mate Choice for Compatibility in a Socially Monogamous Species. PLOS Biology, 2015.
DOI: 10.1371/journal.pbio.1002248

Resveratrol Vs. Exercise

Photo provided by  Anthony L. Hall

Photo provided by Anthony L. Hall

Exercise proves itself yet again as a more powerful way to stay healthy than taking dietary supplements. The department of sport science at Chungnam National University is where research was done to study the effectiveness of exercise versus resveratrol on fighting fat.

Resveratrol is a nutrient found in many foods that has become famous in recent years for its benefits of reducing blood pressure, protecting the heart, and preventing neuro-degenerative diseases. Specifically related to this research, resveratrol can increase metabolism, reduce lipids in the body, and help weight loss. It has been touted as an alternative to exercise.

To test this, 30 obese mice were assorted into three groups of 10: (R) mice were given resveratrol five days per week (10mg/kg of body weight), (E) mice exercised (30-60 minutes of treadmill running for five days a week), (C) mice acted as the control. All mice were on a low fat diet for eight weeks along with their group’s regimen during the study. The concluding results showed an average weight loss of 15% for (E) mice and about 5% for (R) compared to the controls (C). The higher weight loss most likely resulted from increased fat breakdown and blockage of new fat creation seen from exercise.

Although resveratrol has many highly sought after health benefits, it cannot beat good ol’ fashioned exercise in the battle against obesity.

Reference:
Jun Hyun Jeong, Hee Geun Park, Young Ran Lee, Wang Lok Lee. Moderate exercise training is more effective than resveratrol supplementation for ameliorating lipid metabolic complication in skeletal muscle of high fat diet-induced obese mice. The Journal of Exercise Nutricion & Biochemistry, 2015
http://dx.doi.org/10.5717/jenb.2015.19.2.131

Stem Cells Heal Hearts

Photo courtesy of Abigail Droege

Photo courtesy of Abigail Droege

Running up stairs, hiking a new trail, eating great food can all cause acute, unexpected heart attack. That is, given arterial plaque buildup is unstable and ready to pop. Researchers of Zhejiang University, Ningbo University, and the Chinese PLA 305 Hospital, however, found that mesenchymal stem cells can stabilize this heartbreaking plaque.

Cardiovascular disease is the number one most common cause of death worldwide accounting for over 25% of all deaths in 2012. More specifically, one out of every six deaths in the United States is caused by heart attack alone. A large contributing factor to heart attack is accumulated plaque within the walls of arteries. This research focused on a big player in sudden and often unexpected heart attack, vulnerable plaque.

As cholesterol moves through the bloodstream, excess will often accumulate in the walls of blood vessels. Seen as a foreign substance, the cholesterol pool will constantly be attacked by white blood cells. This however, leads to larger plaque buildup as the macrophages and neutrophils are swallowed up by the tarlike plaque. As well, the fibrous cap keeping the plaque away from the blood thins out as cells die. Although the narrowing of arteries is dangerous, acute heart attack is only induced once the lipid deposit ruptures and spills into the bloodstream. This instantly clogs arteries.

Process of vulnerable plaque rupture and arterial blockage

Process of vulnerable plaque rupture and arterial blockage

If inflammation around the plaque could be stopped, white blood cells would not exacerbate growth, the fibrous cap would remain thick and robust, and the fatty clot would not form. The researchers experimented with stem cells’ ability to prohibit inflammation and thereby stabilize plaque deposits.

Forming groups of ten, 30 rabbits were put into either stable plaque (SP), vulnerable plaque (VP), or mesenchymal stem cell (MSC) groups. The groups had plaque formations with no danger of rupture, extreme danger of rupture, or extreme danger of rupture with the addition of MSC’s respectively. To detect plaque stability throughout the project, H&E and Masson staining were used to measure the fibrous cap/lipid core ratio. A high ratio indicated low chance of rupture (stable) while a low ratio indicated high chance of rupture (vulnerable).

After the intravenous introduction of MSC’s, levels of various inflammation markers were measured over a four week period. The following was found:

Pro-inflammatory compound levels (hs-CRP, TNF-a, IL-6, NF-kb)
MSC: Low
SP: Low
VP: High

Anti-inflammatory compound levels (TSG-6, IL-10)
MSC: High
SP: Normal
VP: Normal

As well, the levels of cellular suicide inducer MMP were found to be low in the MSC group. This meant that the stem cells were decreasing inflammation and apoptosis at the site of the plaque deposit. Vulnerable plaques with high risk of inducing abrupt heart attack were transformed into less harmful, stable plaques without the risk of causing sudden cardio-ischemic attacks.

Stem cells seem to be the next big hero of the heart. The list of accomplishments for these little multipotent warriors just keeps on growing.

Reference:
Shuang-shuang Wang, Si-wang Hu, Qing-hua Zhang, Ai-xiang Xia, Zhi-xin Jiang, Xiao-min Chen. Mesenchymal Stem Cells Stabilize Atherosclerotic Vulnerable Plaque by Anti-Inflammatory Properties. PLOS ONE, 2015
http://dx.doi.org/10.1371/journal.pone.0136026