Isabel Rangel Barón: Mass suicide documented in bacteria

Mass suicide documented in bacteria

Microbes pump out acid until they burst.

Some bacteria trigger their own destruction by making their environment uninhabitable, a process that researchers have named ‘ecological suicide’.

Many microbes produce by-products that alter the acidity of their environment, but large pH changes can cause their cells to burst. Christoph Ratzke and Jeff Gore at Massachusetts Institute of Technology in Cambridge and Jonas Denk at Ludwig-Maximilian University of Munich in Germany set out to understand how such alterations impact microbes’ survival. The authors grew a soil bacterium (Paenibacillus tundrae) in test tubes and found that the microbes quickly acidified their environment to a deadly pH 4, wiping the colony out within 24 hours.

Further work showed that a sample of local soil contained five species of bacterium that could drive themselves to extinction by raising acidity to toxic levels. Antibiotics and other substances designed to harm microbes might be counterproductive if they reduce the size of microbial populations enough to prevent self-destructive pH change, the authors say.

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Isabel Rangel Barón: Reduced-calorie diet shows signs of slowing ageing in people

A study of people who reduced the calories they consumed has found the strongest evidence yet that such restrictions can slow down human metabolism. The results raise hopes that a low-calorie lifestyle — or treatments that mimic the biological effects of restricted eating — could prolong health in old age and even extend life.

Past work in many short-lived animals, including worms, flies and mice, has shown that calorie restrictions reduce metabolism and extend lifespan. But experiments in longer-living humans and other primates are more difficult to conduct and have not yet drawn clear conclusions.

The study was part of the multi-centre trial called CALERIE (Comprehensive Assessment of Long term Effects of Reducing Intake of Energy), sponsored by the US National Institutes of Health. The randomized, controlled trial tested the effects of 2 years of caloric restriction on metabolism in more than 200 healthy, non-obese adults.

“The CALERIE trial has been important in addressing the question of whether the pace of ageing can be altered in humans,” says Rozalyn Anderson, who studies ageing at the University of Wisconsin–Madison. She leads one of two large, independent studies on calorie restriction in rhesus monkeys, and began her research career studying calorie restriction in yeast. “This new report provides the most robust evidence to date that everything we have learnt in other animals can be applied to ourselves.”

Precise measurements

Published on 22 March in Cell Metabolism, the latest study1 looked at 53 CALERIE participants who had been recruited at the Pennington Biomedical Research Center in Baton Rouge, Louisiana. This facility is home to 4 of the world’s 20 or so state-of-the-art metabolic chambers, which are like small, sealed hotel rooms that measure minute-by-minute the amount of oxygen that occupants use and how much carbon dioxide they exhale. This allows researchers to track how the occupants use energy with unprecedented precision, says Anderson. The ratio between the two gases, combined with analysis of nitrogen in occupants’ urine, indicates whether the occupant is burning fat, carbohydrate or protein.

The trial participants, aged between 21 and 50, were randomized into two groups: 34 people in a test group reduced their calorie intake by an average of 15%, and 19 people in a control group ate as usual. At the end of each of the two years, they all underwent a range of tests related to overall metabolism and biological markers of ageing, including damage associated with oxygen free radicals released during metabolism. They were also placed in the metabolic chamber for 24 hours.

The scientists found that participants on the diet used energy much more efficiently while sleeping than did the control group. This reduction in their base metabolic rate was greater than would be expected as a result of the test group’s weight loss, which averaged nearly 9 kilograms per participant. All the other clinical measurements were in line with reduced metabolic rate, and indicated a decrease in damage due to ageing.

Model metabolism

Caloric restriction has been known for decades to extend life in different species. In the 1990s, scientists began to identify the genes and biochemical pathways actively involved in longevity in the short-lived worm Caenorhabditis elegans, and in the fly Drosophila melanogaster. These include pathways relevant to insulin sensitivity and the function of mitochondria — tiny structures in cells that use oxygen to generate energy. Subsequent studies revealed that calorie restrictions alter similar pathways in mice and monkeys. Mice on restricted diets can live up to 65% longer than mice allowed to eat freely, and the ongoing monkey studies hint at longer survival and reduced signs of ageing.

“The Rolls-Royce of a human longevity study would carry on for many decades to see if people do actually live longer,” says Pennington physiologist Leanne Redman, the lead author of the latest study. CALERIE ran for just two years, and was designed to see whether a calorie-restricted diet in humans induces some of the same metabolic, hormonal and gene-expression adaptations that are thought to be involved in slowing ageing in other species during long-term caloric restriction.

Few people would want, or be able, to restrict their diet as severely as the participants in the study. “But understanding the biology of how restricting calories extends life will allow us to find easier ways to intervene,” says Anderson.

Redman would like to repeat the study, combining less-ambitious calorie restriction with a diet containing antioxidant food to control oxidative stress, or with a drug such as resveratrol, which mimics key aspects of calorie restriction.

Other scientists are starting to try out the effect of restricting calories for just a few days every month. Such intermittent restriction has been found to be as effective as continuous calorie restriction in protecting mice against diseases of ageing such as diabetes and neurodegeneration2. “I think that’s going to be a way to get all the benefits, without the problems of constant dieting,” says gerontologist Valter Longo of the University of Southern California in Los Angeles, who is embarking on clinical trials of intermittent calorie restriction in various disorders.

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Isabel Rangel Barón: Mystery fiction and being a better internist

As a child, mystery fiction captivated me.  Probably the Bobbsey Twins, then the Hardy Boys and Nancy Drew started the passion.  I remember the TV show Perry Mason, which led me to reading books from the Earl Stanley Gardner series.  Lt. Columbo captivated me.  Discovering Sherlock Holmes was an epiphany.  And throughout my life, I love finding great new mystery authors.

I suspect that my love of mystery fiction made my choice of internal medicine inevitable.  While our field has many dimensions, the core of being a good internist is accurate diagnosis.  While sometimes diagnosis is straightforward, often the patient’s story unfolds much like a mystery novel.

Clinical reasoning has attracted many internists.  The field of cognitive psychology helps us understand the road to excellence and the pitfalls along the way.

But recently I have paid much attention to the brilliance of mystery fiction writers.  Literature (and yes the mystery genre is literature) often gives insights into the human condition.  As I read mysteries or watch mystery TV or film, I often see parallels to our field.  Here are a few examples:

“The world is full of obvious things which nobody by any chance ever observes.” ? Arthur Conan Doyle, The Hound of the Baskervilles

While we often see the patient, our training should teach us to really observe.

“I’ve learned over the years that sometimes if you ask the same question more than once you get different responses.” ? Michael Connelly, The Brass Verdict

We learn this truth as students and residents.  The attending physician often gets a better answer the next day.  Patients think about their situation and often recall details that did not come initially to mind.

“It often seems to me that’s all detective work is, wiping out your false starts and beginning again.”

“Yes, it is very true, that. And it is just what some people will not do. They conceive a certain theory, and everything has to fit into that theory. If one little fact will not fit it, they throw it aside. But it is always the facts that will not fit in that are significant.” ? Agatha Christie, Death on the Nile

How true this is!  Our biggest flaw is falling in love with a diagnosis.  Sometimes the diagnosis is thrust onto to the patient before we see the patient.  We must always re-examine our thoughts for our patients.  If the treatment is working beautifully and the patient’s respond fits our knowledge, we can stick with a diagnosis, but when the course wanders away from the expected we need the courage to doubt ourselves and everyone else.  We must start over from the beginning and not assume anything.

I have found many more great quotes.  Many mystery writers have great insights into the detective process.  And since we pride ourselves as detectives, I believe we can learn from their wisdom.

If you have quotes from mystery writers that make important points, please share them with me and our readers.  I will gladly share them with attribution on this blog and on twitter.

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Isabel Rangel Barón: An efficient deep-learning tool for detecting eye disease

An efficient deep-learning tool for detecting eye disease

A new artificial-intelligence tool deploys a highly efficient form of deep learning to diagnose eye disease from medical images.

Convolutional neural networks are deep-learning algorithms adept at processing images, but researchers typically need to train them on more than a million medical images before they can test how well the algorithms work. Kang Zhang at the University of California, San Diego, in La Jolla and his colleagues created a kind of convolutional neural network capable of learning with many fewer images.

The team trained the model on 108,000 images of retinas. All had been classified by experts as either healthy or showing signs of a leading cause of blindness: macular degeneration or diabetic macular edema, a build-up of fluid in the retina. The algorithm identified critical cases of these conditions as accurately as six experts in ophthalmology.

The model also identified pediatric pneumonia from chest X-rays, suggesting that the technique could be broadly applied across medicine.

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INTERESTING! Isabel Rangel Barón: Better Lifestyle Anyone?

If you are the kind of person who wants to have a better health, you should not hesitate looking for a better diet. There are things that you can’t just eat very often if you want to have a better life. As an example, people who eats often way too much are literally risking their health.

This is not good because sometimes, that much grease can be harmful for your body. There are people who end up in a surgery because of eating too often. It may sound excessive but it is not far away from reality.

If you are a chubby guy, you have to start training a bit more. Try to consider exercising as something good for your life and do not expect fast results either. Maybe the best thing you can do is to train yourself to get used to the idea of enjoying to work out. If you enjoy doing your exercises at least 3 times per week, there will be a moment in which you will see results without any doubt.

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It Is necessary that you also do not eat that much junk food as said before and if you combine it with a good diet, you will surely not be left behind when it comes to entering the group of healthy people.

It would be advisable that you eat more fruits and vegetables if you want to have a good flavor food at the same time you eat something that is better for your body.

You may not want to have that much time working out in a gym but if you are the kind of outdoors person, walking and jogging would be definitely good ideas. Do not stop doing this because that it s going to help you out a lot and you should not stop liking to work out in a different place than most people.

Sometimes it is about being different from the rest and if you look for improvement, you can’t just be watching TV as most people do when they do not work out.

IMPORTANT! Isabel Rangel Baron: Health and Lifestyle: Good Ideas

If you want to have a healthier life, you should not hesitate on trying out these ideas:

Swimming more often: that can be a very entertaining way to improve your health. Moreover, chances are that you get a better body since this is a complete work out. Your body would be moving in the pool often and this would unavoidably make you r arms, legs and back work out a lot. Consider it if you do not have any problem with wearing a bath suit while working out!

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Parkour: this is for those ones who want to try a sport which implies more adrenaline and movement. This is not a sport that you practice in the water but on solid ground. This means that you will need to do different tricksrolling, and jumps and so on. You may be a bit skeptical on practicing such a sport if you have not raining but the good news is that you can always find a tutorial on YouTube to get started. Expert parkour is very interesting and the work out that it gives to your body is very complete. It is going to be a very nice idea if you want to be fit without needing a gym but do not stop being preventive while training.

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These two sports are going to be very helpful if you are willing to get more of a better healthy life. Also, consider going to a place you like while practicing since you should be often going to a place you enjoy so you do not see it as an obligation. A sport that gives you a good health should be fun too so do not stop trying out these so you can avoid those gym routines which may be not of your taste.

AMAZING! Isabel Rangel Barón: Let’s get Thinner!

If you want to be a person with a better weight, you should understand that there are some tips that can use today. Time to get thin! See the tips Isabel Rangel Barón brought today for you!

In fact, being thinner is into only matter of working out every single day but actually of combination between sleep, eating healthy and working out.

Many people would agree with the fact that there are many myths on the physical health area. Then this means that you will need to focus a lot on discovering what is better for you and there are times in which a nutritionist will be the more practical method to make that sure.

You should remember that sleep time is critical. If you do not sleep from 7 to 8 hours, you cannot expect being thinner in the long term because of the lack of energy you would have if you sleep less time. You need to take care of your body and remember that if you are willing to change, then change have to be made.

Your vegetable can be a good idea. Many people do not like broccoli but it is a great alternative to as well prevent cancer and getting good energy during the day avoiding high fat meats.

The best you can do is to have a better knowledge on what to do and this will imply to have a better understanding on how much time you have to invest on getting thinner while working out. You do not need to be in a gym either. A long as you do good exercise at least 3 times per week, you will be seeing results at some point.

You should stop having bad habits such a sitting for long periods of time without doing anything and remember that this is going to have important and useful results for your life.