Tuesday, January 31, 2017

Novel DNA Base Pairs

At left, a redesigned protein (not directly related to the paper discussed here).  By Pablo.gainza - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=25728531

This article is on a more basic science topic we usually don’t discuss here, but I thought it is very interesting and useful to introduce such study to a more general audience. Abstract:

All natural organisms store genetic information in a four-letter, two-base-pair genetic alphabet. The expansion of the genetic alphabet with two synthetic unnatural nucleotides that selectively pair to form an unnatural base pair (UBP) would increase the information storage potential of DNA, and semisynthetic organisms (SSOs) that stably harbor this expanded alphabet would thereby have the potential to store and retrieve increased information. Toward this goal, we previously reported that Escherichia coli grown in the presence of the unnatural nucleoside triphosphates dNaMTP and d5SICSTP, and provided with the means to import them via expression of a plasmid-borne nucleoside triphosphate transporter, replicates DNA containing a single dNaM-d5SICS UBP. Although this represented an important proof-of-concept, the nascent SSO grew poorly and, more problematically, required growth under controlled conditions and even then was unable to indefinitely store the unnatural information, which is clearly a prerequisite for true semisynthetic life. Here, to fortify and vivify the nascent SSO, we engineered the transporter, used a more chemically optimized UBP, and harnessed the power of the bacterial immune response by using Cas9 to eliminate DNA that had lost the UBP. The optimized SSO grows robustly, constitutively imports the unnatural triphosphates, and is able to indefinitely retain multiple UBPs in virtually any sequence context. This SSO is thus a form of life that can stably store genetic information using a six-letter, three-base-pair alphabet.

In summary, bacteria are being engineered to stably contain within their genome novel DNA base pairs, a phenomenon that can, with further work, expand the genetic information contained in DNA and therefore expand the products that can be generated from these novel genes, bestowing unique and/or enhanced physiological function for the organism.  

Sunday, January 29, 2017

For the love of cheese




I love cheese; however, I am aware that too much of it is not great for my health. Therefore, I try to reduce the fat intake from cheese, without giving up the taste and flavor of cheese.

My first trick is to strain fat-free yogurt, add garlic, salt, and olive oil. This is a pretty good substitute for my favorite feta cheese. Of course, you could make it fancier by adding dill, crushed walnuts, olives, or even cucumbers (as in Tzatziki).  The yogurt spread on toasted bread.

My second approach is to crumble feta cheese with a fork and add non-fat yogurt to the density of a spread. To diversify the taste, add  a bit of olive oil and spices (e.g., black pepper, garlic, chopped baked and peeled peppers, chopped olives, red pepper flakes, etc.).

I also cook with cheese in a way that the taste is enhanced despite the small amount of cheese used. Here are two ideas for baked sandwiches:


Baked cheese sandwiches

1. Use dense type of bread. Mix crumbled feta cheese with a raw egg (add black pepper, if you like), and spread on slices of bread. Bake/grill until the egg is not runny. You could also butter the bread first, and then spread the egg-cheese mixture.

2. Grate cheese on top of a slice of bread, add your favorite spices (e.g., black pepper, hot pepper flakes, basil or savory) and bake.

Here is one appetizer recipe:


Baked peppers with cheese
Use ready-to-eat baked and peeled peppers (I buy Daily Chef Whole Roasted Peppers, the link is below). Cut thin slices of your favorite cheese, stuff them into the peppers. Heat a pan, oil it (with olive oil or use no-stick spray) and warm up the peppers on both sides until the cheese starts melting. Serve warm or cold.


Here is also one very "cheesy" recipe for a main dish:

Poached eggs with feta cheese and yogurt  

For this dish, you will need to poach a few eggs. I plan on two eggs per person. Break the eggs carefully into a pan of boiling water and cook.

For serving, prepare crumbled feta cheese mixed with yogurt and crushed garlic. Distribute the mixture into individual plates. Once the poached eggs are ready, drain them on a paper towel and then transfer onto the cheese-yogurt “bedding” in each individual dish. 


In a clean pan, melt a bit of butter (I use Smart Balance instead of butter), add a pinch of paprika, swirl quickly, and pour this fragrant mix on top of each egg (a teaspoon per egg would do).

Saturday, January 28, 2017

Probiotics For Clostridium Difficile Prevention?

At left, how probiotics work; By Rachelshoemaker - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=54240651

Clostridium difficile is a common cause of acquired GI infections in the medical setting, often cuaing severe diarrhea. There is a school of thought that suggests that colonizing the gut with beneficial bacteria can inhibit infection with harmful bacterial species. This study suggests "moderate quality evidence" that probiotics can be used to prevent diarrhea from Clostridium difficile.  The conclusions from their abstract:

AUTHORS' CONCLUSIONS:
Based on this systematic review and meta-analysis of 23 randomized controlled trials including 4213 patients, moderate quality evidence suggests that probiotics are both safe and effective for preventing Clostridium difficile-associated diarrhea.

If supported by further research, this would certainly be welcome news, to reduce the incidence of the severe problems that accompany these sorts of infections, and once again demonstrates the positive value of a proper gut microbiota.


Thursday, January 26, 2017

Folate Restriction And Breast Cancer

An interesting study using cell culture suggests that folate restriction may be beneficial for breast cancer.  Abstract:

Folate coenzymes are involved in biochemical reactions of one-carbon transfer, and deficiency of this vitamin impairs cellular proliferation, migration, and survival in many cell types. Here, the effect of folate restriction on mammary cancer was evaluated using three distinct breast cancer subtypes differing in their aggressiveness and metastatic potential: noninvasive basal-like (E-Wnt), invasive but minimally metastatic claudin-low (M-Wnt), and highly metastatic claudin-low (metM-Wntliver) cell lines, each derived from the same pool of MMTV-Wnt-1 transgenic mouse mammary tumors. NMR-based metabolomics was used to quantitate 41 major metabolites in cells grown in folate-free medium versus standard medium. Each cell line demonstrated metabolic reprogramming when grown in folate-free medium. In E-Wnt, M-Wnt, and metM-Wntliver cells, 12, 29, and 25 metabolites, respectively, were significantly different (P < 0.05 and at least 1.5-fold change). The levels of eight metabolites (aspartate, ATP, creatine, creatine phosphate, formate, serine, taurine and β-alanine) were changed in each folate-restricted cell line. Increased glucose, decreased lactate, and inhibition of glycolysis, cellular proliferation, migration, and invasion occurred in M-Wnt and metM-Wntliver cells (but not E-Wnt cells) grown in folate-free versus standard medium. These effects were accompanied by altered levels of several folate-metabolizing enzymes, indicating that the observed metabolic reprogramming may result from both decreased folate availability and altered folate metabolism. These findings reveal that folate restriction results in metabolic and bioenergetic changes and a less aggressive cancer cell phenotype.
IMPLICATIONS:
Metabolic reprogramming driven by folate restriction represents a therapeutic target for reducing the burden of breast cancer. Mol Cancer Res; 15(2); 1-12. ©2016 AACR.

Of course, one study using "transgenic mouse mammary tumor" cells in a tissue culture model system is not definitive for human patient treatment, and so much more work is needed to better evaluate the role of folate restriction as one therapeutic approach for breast (and other?) cancer. Nevertheless, this is a potentially useful example of the interplay between diet, nutrients, and cancer development.

Wednesday, January 25, 2017

The Exercise Paradox

At left, man running.  By Graysonbay - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=12174170

There is an interesting article in the latest Scientific American about the “Exercise Paradox.” Perhaps you may have heard that diet is more important than exercise in losing weight. This article discusses the finding that daily caloric expenditure seems to be similar between peoples despite big differences in their activity level. Therefore, very active hunter-gatherers expend roughly the same number of calories as sedentary Western populations. The difference between the two in obesity is not due to caloric expenditure but caloric intake; thus, the authors claim that obesity is a disease of “gluttony not sloth.” In other words, the best way to lose weight is to adjust your diet (reduce caloric intake for example), exercise won’t do the trick (there have been a number of articles recently about this).

As to why caloric expenditure is similar despite ostensible differences in activity, we are not sure. The amount of calories expended per type of physical; activity seems to be the same between populations. Perhaps the hunter-gatherers rest more when not overly active or sleep better. Another intriguing possibility is that their bodies have adjusted to use less calories in regular “housekeeping activities” – the normal functions of bodily maintenance. In fact, the authors speculate that one benefit of exercise is to divert the body’s energy away from such potentially harmful processes as inflammation. And of course, exercise has a wide variety of positive effects on health and fitness – it’s just not the main vehicle for losing weight, which has to be diet.

How about the theory that increasing muscle mass is metabolically beneficial because muscle burns more calories at rest than does fat? This is still open to question, but this article makes one wonder if this is true. There is also the discussed phenomenon that the body can adjust to diet and decrease caloric expenditure, making it harder to lose weight by diet alone – is this perhaps where exercise or muscle mass plays a role? One possible advantage of so-called “cheat days” or “cheat meals” in a more restricted diet is to reset the body’s metabolic set point and once again allow weight loss when the (brief) “cheating” is over.

Tuesday, January 24, 2017

BOOST YOUR BRAIN: SKIP THE DRUGS, EXERCISE INSTEAD



He has done it again. 

The anonymous author of the YouTube channel What I've Learned has uploaded another brilliant video. This time it is on exercise and what exercise does for your brain, WHY Exercise is so Underrated (Brain Power & Movement Link).
 

I would suggest that you also check the website of the author, as the transcripts of the What I've Learned videos are posted there.

For more information on the topic, read my previous post, Jumping jacks or medications. I recently re-read it, and I realized that I was naïve when advising my readers under Actionable, “Dear doctors, instead of ADHD medications, would you please prescribe jumping jacks to our children?


Why is this naïve? Because the frightening truth is that your doctors might be on the same medications themselves. I have had numerous conversations with medical students who have seen the inner works of clinical practices and I assure you that not only the medical students, but also some of the young MDs are “enhancing” their everyday professional performance with drugs. 


Therefore, do not expect that the doctors will help you overcome your dependence on pharmaceuticals. You have to take care of yourself. The more you know about psychotropic drugs, the better you will protect yourself.

Saturday, January 21, 2017

Oatmeal Breakfast Bars

What do you have for breakfast?

Until recently I was having two slices of toasted bread (double fiber or whole wheat), sprinkled with olive oil and 3 - 4 spoonfuls of sunflower seeds on top, a cube of feta cheese and a cup of yogurt drink (plain yogurt mixed with water). My veggies and fruit are reserved for snacks throughout the day.

I decided to change my breakfast, however, after reading a scary story about contaminated seeds (including sunflower seeds).

To replace my usual breakfast, I developed a recipe for oatmeal breakfast bars that is a variation of my oatmeal-walnut crackers recipe. These bars have no sugar, and no preservatives and unwanted chemicals. The taste is mild and pleasant.


If you have a sweet tooth, you may prepare the sweet version of oatmeal bars (no sugar added).


The two recipes for oatmeal bars are suitable not only for breakfast, but also for bring-to-work lunches.

Oatmeal Breakfast Bars

You need:
3 cups oatmeal, 1 cup chopped walnuts, 1 cup whole wheat flour, 3 eggs, 2 Tbsp olive oil, 1/2 cup plain yogurt (I buy low fat or no fat), 2 tsp baking soda, 2 tsp salt, optional spices (black pepper, turmeric, caraway seeds, cayenne pepper).

Instructions:

In a big bowl, mix oatmeal, walnuts, flour, baking soda, all spices and salt. Make a well in the middle of the oatmeal mixture and in it, pour the three eggs mixed with olive oil and yogurt. Incorporate all ingredients by hand and spread the dough on top of an oiled cookie sheet. Press the dough down to approximately one inch of thickness. Bake at 400F for 15 minutes and after turning off the heat, leave the oatmeal bars for another 5 - 6 minutes in the oven. After cooling, slice into the desired size bars and keep in the refrigerator.

Thursday, January 19, 2017

Stem Cell Therapy For ALS

At left, Lou Gehrig
By Pacific & Atlantic Photos, Inc - Heritage Auctions, Public Domain, https://commons.wikimedia.org/w/index.php?curid=41470554

Here is a review on the potential of stem cell therapy to reduce disease progression in amyotrophic lateral sclerosis (ALS). Abstract:

Amyotrophic lateral sclerosis (ALS) is an unusual, fatal, neurodegenerative disorder leading to the loss of motor neurons. After diagnosis, the average lifespan ranges from 3 to 5 years, and death usually results from respiratory failure. Although the pathogenesis of ALS remains unclear, multiple factors are thought to contribute to the progression of ALS, such as network interactions between genes, environmental exposure, impaired molecular pathways and many others. The neuroprotective properties of neural stem cells (NSCs) and the paracrine signaling of mesenchymal stem cells (MSCs) have been examined in multiple pre-clinical trials of ALS with promising results. The data from these initial trials indicate a reduction in the rate of disease progression. The mechanism through which stem cells achieve this reduction is of major interest. Here, we review the to-date pre-clinical and clinical therapeutic approaches employing stem cells, and discuss the most promising ones.

Here is a paper online for free, which contains this informative figure. Essentially, possible mechanisms by which stem cells can improve symptoms of ALS include helping to rebuild or maintain neural circuitry damaged by the disease, facilitate growth of nervous tissue, reduce toxicity of nervous tissue, support functional neuromuscular junctions, and reduce inflammation by modulating the immune response. In theory, these mechanisms could reduce progression of further damage and possibly even reverse some damage that has occurred. All of this is in very early stages, but there seems to be some promising results.





Maintaining a Healthy Diet While Traveling


Some tips on how to eat healthy when traveling come from this excellent article:

Business trips have plenty of perks -- new travel destinations, expense-account meals and an excuse to get out of the office. But road trips have a common pitfall as well in terms of the poor food choices you may make -- from indulgent client dinners and unhealthy airport fare to the temptation of room service. All can quickly derail your healthy lifestyle.

The good news is that it’s easier than you think to stay on track while you travel. If you’re actively trying to lose weight or managing a chronic condition like diabetes, be sure to work with your healthcare provider to create a plan that suits your needs. If you’re just trying to maintain your healthy habits while you’re on the go, here are some simple tips to keep you feeling great.

The article continues to give a series of useful tips. 


It is important to maintain a healthy lifestyle (in terms of diet and exercise) when traveling. 

However, you should not be discouraged, if you cannot perfectly replicate your home program. Do the best you can, and maintain as much of your routine as possible. 

Remember that many times “the perfect is the enemy of the good.” If you can maintain most of your health agenda on the road, that will be good enough. Of course, the more you travel, the more important it will be to better replicate your home program when on the road. 

If you are going to be away for only a few days once or twice a year, it’s not a big deal, but weeks away from home necessitate more stringent attempts to optimize the situation.

Additional advice comes from my wife:
 
Before my trips, I always Google-search my final destination for nearby health food stores, pharmacies and supermarkets. Once I am at my destination, I buy fruit, vegetables (usually baby carrots), nuts, crackers, and plain yogurt (if the hotel room has a refrigerator). I do not load my luggage with food, since I travel with a small bag that fits any overhead compartment in any plane. The only food I do carry with me is the food I consume during the travel hours, since the food choices at the airports are surprisingly unhealthy, expensive, or both.

Saturday, January 14, 2017

Weekend cooking: Spinach-potato torte


I cook only cheap and healthy dishes. I usually find an idea for a recipe, and then experiment with it. I adjust the recipe to what I have at hand, and substitute less healthy ingredients with healthier products.  Below is one of my new experiments for a lunch meal.


Fun in the kitchen


Spinach-potato torte

You need: 

8-10 small to medium potatoes, washed, cleaned and cut into 1/3 inch slices (I used red potatoes, but any type would do), 10 eggs, 1 pack frozen chopped spinach, 1 large onion, chopped, 1 cup of nonfat yogurt, 1 cup crumbled feta cheese, 3 Tbsp whole wheat flour, 1/3 tsp of baking soda. Salt, black pepper, and 4 Tbsp olive oil.

 


Arrange the microwaved potatoes in a layer
Instructions:
Arrange the potatoes in a microwaveable dish (I pile the slices on top of each other), and microwave for 10-15 minutes to soften the potatoes a bit (but not cook completely). In a large pan (mine is 10/13 inches), mix the potato slices with 2 Tbsp of olive oil, black pepper, and salt. Arrange the slices in a layer. 
In a pan, cook the onion in 2 Tbsp of olive oil until caramelized, and add the thawed spinach. In a large bowl, mix the spinach-onion with eggs, cheese, yogurt, flour, baking soda, salt, and black pepper.  Pour the egg-spinach mixture on top of the potatoes and bake at 375-400°F for approximately one hour, or until the eggs are completely cooked.

Here is the finished product: