Tag Archives: human health

Cats Prevent Heart Attacks

I suppose some people don’t know how great cats are 🙂 Here is news of a study showing that those with cats are less likely to have heart attacks.

Whether it’s a frisky kitten or a tubby tabby, a cat at home could cut your heart attack risk by almost a third, a new study suggests.
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In the new study, Qureshi’s team analyzed data on 4,435 Americans, aged 30 to 75, who took part in the federal government’s second National Health and Nutrition Examination Study, which ran from 1976-1980. According to the data in the survey, 2,435 of the participants either owned a cat or had owned a cat in the past, while the remaining 2,000 had never done so.

Qureshi’s team then tracked rates of death from all causes, including heart and stroke. Cat owners “appeared to have a lower rate of dying from heart attacks” over 10 years of follow-up compared to feline-free folk, Qureshi said. The magnitude of the effect — a 30 percent reduction in heart attack risk — “was a little bit surprising,” he added. “We certainly expected an effect, because we thought that there was a biologically plausible mechanism at work. But the magnitude of the effect was hard to predict.”

This is just one more example of cat power. As we have shown before: cats can be photographers and also protect you from bears.

Have a nice weekend.

The Risks of Scanning

The Risks of Scanning by Nayer Khazeni, M.D

When ordered by your doctor in the proper setting, any risks of CT scans are far outweighed by their potential benefits. They are one of modern medicine’s greatest diagnostic tools, used to examine any part of your body and, increasingly, to guide minimally invasive procedures previously performed with surgery. CT rapidly rotates X-ray beams around you, obtaining images from different angles that a powerful computer then compiles to build, slice by slice, highly detailed pictures of your insides.
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The impressive level of detail that CT provides can also cause confusion. In CTs of healthy adults, more than 90 percent of findings are “false positives.”
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Full-body CT scans cost $500 to $1,000. Insurance companies do not cover the cost, but may use any detected abnormality to raise your premiums or limit future coverage. There are no public health organizations that advocate the use of full body or cardiac CT scans in healthy adults, and the American College of Radiology and American Heart Association have released statements recommending against them.

Parasitic Worms Reduce Hay Fever Symptoms

Parasitic worms reduce hay fever symptoms

Researchers are seeking to use the ability of the hookworm, Necator americanus, to suppress immune system responses that occur in conditions including Crohn’s disease, multiple sclerosis, asthma and other allergies. Recently-completed studies suggest giving worms to people with hay fever is safe, and potentially beneficial.
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Scientists have suggested a lack of such intestinal parasites has left those in the developed world more vulnerable to diseases caused an overactive immune system.

Parasite Rex is an excellent book exploring similar ideas and more on the interaction of parasites with hosts. And from Good Germs Bad Germs, page 100:

in 1999 the Dutch biologist Maria Yazdanbakhsh found that eliminating intestinal worms from infected children in African villages immediately predisposed them to allergies.”

Surprising New Diabetes Data

But these measures are only surrogates for disease. And in many cases, the connection between “better” numbers and better health is tenuous. In the case of cholesterol, many people won’t see a health benefit from lower numbers.

Now comes yet another sobering reminder that lowering a surrogate marker doesn’t necessarily bring better health. On Feb. 6, the National Institutes of Health announced it was halting a key trial for diabetes. Researchers had hoped the trial, dubbed ACCORD (Action to Control Cardiovascular Risk in Diabetes), would show that more aggressive lowering of blood sugar would significantly reduce deaths. Instead, the opposite happened. More people in the intensive treatment group died than in the group getting standard care. “A thorough review of the data shows that the medical treatment strategy of intensively reducing blood sugar below current clinical guidelines causes harm in these…patients,” says Dr. Elizabeth Nabel, director of the National Heart, Lung & Blood Institute.

Scientific study often results in less than clear conclusions, especially in complex systems. There is great difficulty understanding what is actually going on, what interactions are present, what factors are significant, etc.. One of the great problems with the low level of scientific literacy in the USA is so many people think science is about simple absolute truth.

Scientific inquiry, especially related to health care, must attempt to gain insights from confusing signals. To gain scientific literacy one must understand basics concepts, like data is a proxy for what you aim to understand. To understand yourself you need to accept that science is not math. For a long time we are going to have to do our best to build up our understanding of human health (and other complex systems) as best we can. We need to be able to sort out what are solid conclusion, what are guesses, what seem like reasonable explanation and what level of confidence we can have in statements.

It is not enough to learn facts we need to be able to think scientifically and comprehend the subtleties surrounding the advances in scientific understanding. Some criticize newspapers and popular science for providing too simplistic a view of new scientific knowledge. While this can be a problem I really see the problem much more serious if people read obviously overly simplistic articles and don’t understand that it is just scratching the surface. The reader needs to take responsibility too. I enjoy many great articles that gloss over many of the details but provide a quick view of intriguing new breakthroughs.

Clues to Prion Infectivity

Structural Studies Reveal New Clues to Prion Infectivity

One of the unexplained questions facing prion researchers is how a single prion can apparently assume different conformations — with each conformation having different disease or phenotypic properties. Previous structural studies of prions had not yielded a clear understanding of the basis of strains because the prion protein is large and complex. Due to the size and complexity of prions, studies utilizing x-ray crystallography, a technique commonly used to determine the structure of proteins and other molecules, have been limited to short peptide fragments of the prion protein.

“There have been a number of fairly low-resolution pictures of prions that more or less proved that these different strains were in different conformations; but they really hadn’t established the nature of the different conformations,” Weissman said. “It was really a big black box. We basically didn’t have the conformation of any single prion, let alone the two prion protein strains in two different conformations.”
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““In our minds, our findings brought to a certain level of closure the understanding of the structural differences underlying strains,” said Weissman. “Now we understand the structural differences. We also have an idea how those differences lead to the differences in physical properties, and, in turn, how these differences in the physical properties lead to the phenotypic differences. We are starting to go all the way from the structural understanding of the different strains up to in vivo understanding of why they cause different behaviors inside the cell.”

Weissman noted that the findings offer a broader lesson to researchers studying prions and other proteins whose misfolding can cause disease. “Certainly, a bottom line from this study is that the rules of protein folding and the rules of protein misfolding are fundamentally different,” he said. “In many ways, we have to relearn basic principles of how proteins misfold. We have to forget many of the rules we learned from textbooks about protein folding because they are not necessarily applicable.”

Prions are very interesting. Related posts: Scientists Knock-out Prion Gene in Cows – Gene Study Finds Cannibal Pattern – Open Access Education Materials on Protein Folding

Lifestyle Drugs and Risk

I see taking drugs as risky. Certain drug have long histories and seem safe and even seem to have positive side effect like Aspirin (though even it is not without risks – see below). Even if a drug has a good chance of a positive result in treating some medical condition – assuming it is otherwise safe is not wise. I believe you have have a significant positive known benefit to consider taking drugs given the unknown problems that are likely to be lurking. I find the pop a pill culture for anything that might be a minor annoyance to be foolish – taking risks without consideration. Taking drugs entails taking a risk and the more you take the risks of interactions and cumulative effects increase the risks to you. Business Week (somewhat surprising given the huge amount drug makers pay to advertise lifestyle drugs) has a decent article pointing out some of the foolishness involved in the Lifestyle Drug Binge:

The renewed excitement is most evident in four treatment areas that account for the bulk of lifestyle-drug sales: weight loss, hair loss, sleep, and sexual dysfunction.

This trend is surprising because such treatments can expose patients to risks, sparking criticism of drug companies at a time when patient safety is already under a spotlight. Lifestyle drugs are defined loosely as products used to treat conditions that are not life-threatening. Because people take them over long periods of time, sometimes on a daily basis, they may be more dangerous than they first appear.

We have found amazingly helpful and useful drugs. This is great. But people need to remember these drugs are not without potential negative consequences. Take advantage of them when appropriate but don’t forget the risks each instance has for negative side effects. Related: health care improvement articles – health care blog posts
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How The Brain Rewires Itself

How The Brain Rewires Itself:

The finding was in line with a growing number of discoveries at the time showing that greater use of a particular muscle causes the brain to devote more cortical real estate to it. But Pascual-Leone did not stop there. He extended the experiment by having another group of volunteers merely think about practicing the piano exercise. They played the simple piece of music in their head, holding their hands still while imagining how they would move their fingers. Then they too sat beneath the TMS coil.

When the scientists compared the TMS data on the two groups–those who actually tickled the ivories and those who only imagined doing so–they glimpsed a revolutionary idea about the brain: the ability of mere thought to alter the physical structure and function of our gray matter.

Self-Assembling Cubes Could Deliver Medicine

Nanocubes photos

Tiny Self-Assembling Cubes Could Carry Medicine, Cell Therapy – News Release from Johns Hopkins (pdf format)

Details of photos: “Scanning electron microscopy images of image of (A) a hollow, open surfaced, biocontainer, and (B) a device loaded with glass microbeads. (C) Fluorescence microscopy images of a biocontainer loaded with cell-ECM-agarose with the cell viability stain, Calcein-AM. (D) Release of viable cells from the biocontainer.”

Johns Hopkins researchers have devised a self- assembling cube-shaped perforated container, no larger than a dust speck, that could serve as a delivery system for medications and cell therapy.

When the process is completed, they form a perforated cube. When the solution is cooled, the solder hardens again, and the containers remain in their box-like shape.

“To make sure it folds itself exactly into a cube, we have to engineer the hinges very precisely,” Gracias said. “The self-assembly technique allows us to make a large number of these microcontainers at the same time and at a relatively low cost.”

Gracias and his colleagues used micropipettes to insert into the cubes a suspension containing microbeads that are commonly used in cell therapy. The lab team showed that these beads could be released from the cubes through agitation. The researchers also inserted human cells, similar to the type used in medical therapy, into the cubes. A positive stain test showed that these cells remained alive in the microcontainers and could easily be released.

And they are “always on the lookout for exceptional and highly creative undergraduate, graduate students and post-doctoral candidates” – maybe you.