Posts filed under ‘Health’
Breakthrough: nerve connections are regenerated after spinal cord injury
Sun, 08/08/2010 – 17:46 – NLN
Researchers for the first time have induced robust regeneration of nerve connections that control voluntary movement after spinal cord injury, showing the potential for new therapeutic approaches to paralysis and other motor function impairments.
In a study on rodents, the UC Irvine, UC San Diego and Harvard University team achieved this breakthrough by turning back the developmental clock in a molecular pathway critical for the growth of corticospinal tract nerve connections.
They did this by deleting an enzyme called PTEN (a phosphatase and tensin homolog), which controls a molecular pathway called mTOR that is a key regulator of cell growth. PTEN activity is low early during development, allowing cell proliferation. PTEN then turns on when growth is completed, inhibiting mTOR and precluding any ability to regenerate.
Trying to find a way to restore early-developmental-stage cell growth in injured tissue, Zhigang He, a senior neurology researcher at Children’s Hospital Boston and Harvard Medical School, first showed in a 2008 study that blocking PTEN in mice enabled the regeneration of connections from the eye to the brain after optic nerve damage.
He then partnered with Oswald Steward of UCI and Binhai Zheng of UCSD to see if the same approach could promote nerve regeneration in injured spinal cord sites. Results of their study appear online in Nature Neuroscience.
“Until now, such robust nerve regeneration has been impossible in the spinal cord,” said Steward, anatomy & neurobiology professor and director of the Reeve-Irvine Research Center at UCI. “Paralysis and loss of function from spinal cord injury has been considered untreatable, but our discovery points the way toward a potential therapy to induce regeneration of nerve connections following spinal cord injury in people.”
According to Christopher & Dana Reeve Foundation data, about 2 percent of Americans have some form of paralysis resulting from spinal cord injury, which is due primarily to the interruption of connections between the brain and spinal cord.
An injury the size of a grape can lead to complete loss of function below the level of injury. For example, an injury to the neck can cause paralysis of arms and legs, loss of ability to feel below the shoulders, inability to control the bladder and bowel, loss of sexual function, and secondary health risks including susceptibility to urinary tract infections, pressure sores and blood clots due to an inability to move the legs.
“These devastating consequences occur even though the spinal cord below the level of injury is intact,” Steward noted. “All these lost functions could be restored if we could find a way to regenerate the connections that were damaged.”
He and his colleagues are now studying whether the PTEN-deletion treatment leads to actual restoration of motor function in mice with spinal cord injury. Further research will explore the optimal timeframe and drug-delivery system for the therapy.
Tel Aviv University study offers an evolutionary approach for today’s fertility problems
About 10% of all couples hoping for a baby have fertility problems. Environmentalists say pollution is to blame and psychiatrists point to our stressful lifestyles, but evolutionary biologist Dr. Oren Hasson of Tel Aviv University’s Department of Zoology offers a different take. The reproductive organs of men and women are currently involved in an evolutionary arms race, he reports in a new study. And the fight isn’t over yet.
“The rate of human infertility is higher than we should expect it to be,” says Dr. Hasson. “By now, evolution should have improved our reproductive success rate. Something else is going on.” Combining empirical evidence with a mathematical model developed in cooperation with Prof. Lewi Stone of the department’s Biomathematics Unit, the researchers suggest that the bodies of men and women have become reproductive antagonists, not reproductive partners. The conclusions of this research were published recently in the journal Biological Reviews.
Favoring the “super-sperm”
Over thousands of years of evolution, women’s bodies have forced sperm to become more competitive, rewarding the “super-sperm” — the strongest, fastest swimmers — with penetration of the egg. In response, men are over-producing these aggressive sperm, producing many dozens of millions of them to increase their chances for successful fertilization.
But these evolutionary strategies demonstrate the Law of Unintended Consequences as well, says Dr. Hasson. “It’s a delicate balance, and over time women’s and men’s bodies fine tune to each other. Sometimes, during the fine-tuning process, high rates of infertility can be seen. That’s probably the reason for the very high rates of unexplained infertility in the last decades.”
The unintended consequences have much to do with timing. The first sperm to enter and bind with the egg triggers biochemical responses to block other sperm from entering. This blockade is necessary because a second penetrating sperm would kill the egg. However, in just the few minutes it takes for the blockade to complete, today’s over-competitive sperm may be penetrating, terminating the fertilization just after it’s begun.
Sexual evolution explained
Women’s bodies, too, have been developing defenses to this condition, known as “polyspermy.” “To avoid the fatal consequences of polyspermy, female reproductive tracts have evolved to become formidable barriers to sperm,” says Dr. Hasson. “They eject, dilute, divert and kill spermatozoa so that only about a single spermatozoon gets into the vicinity of a viable egg at the right time.”
Any small improvement in male sperm efficiency is matched by a response in the female reproductive system, Dr. Hasson argues. “This fuels the ‘arms race’ between the sexes and leads to the evolutionary cycle going on right now in the entire animal world.”
Advice for doctors and marriage counselors
Sperm have also become more sensitive to environmental stressors like anxious lifestyles or polluted environments. “Armed only with short-sighted natural selection,” Dr. Hasson argues, “nature could not have foreseen those stressors. This is the pattern of any arms race. A greater investment in weapons and defenses entails greater risks and a more fragile equilibrium.”
Dr. Hasson says that IVF specialists can optimize fertility odds by more carefully calculating the number of sperm placed near the female ova. And nature itself may have its say as well. Sexually adventurous women, like females of many birds and mammals who raise their offspring monogamously but take on other sexual partners, help create a more fertile future. But not always, says Hasson and Stone’s mathematical model ― certain types of infertile sperm race to the egg as competitively as any healthy sperm, and may block the sperm of a fertile lover.
But whatever the source of infertility, Dr. Hasson, who also works as a marriage counselor, can’t recommend cheating, not even as an evolutionary psychologist. Infertile marriages can be stressful, but unlike birds, we have the capacity for rational thinking. He advises infertile couples to openly communicate about all their options, and seek counseling if necessary.
Weed is a drug. Drugs are bad. Wine is alcohol. Politicians drink alcohol. Therefore, alcohol is ok and weed is not. Say WHAT? This is how most people function when it comes to issues of right and wrong. And while maybe it’s not as simple as caveman grunting, the way we’re wired to think is actually as a result of systemic beliefs created by institutions. Government is an institution. We live under government. Government creates drug laws. Drug laws are institutional. See what I mean?
Basically, if we don’t question what’s created by institutions, then we are products of that institution, and created by that institution for the sake of its perpetuation. This doesn’t really sound like LIFE, to me. It sounds like Alias, or Twilight, or some other fictionalized scary story. And so, we must question.
That’s what marijuana legalization advocate Steve Fox is doing, in the new book  Marijuana is Safer: So Why Are We Driving People to Drink? And he’s not a Judd Apatow character, ripping bong hits. This ish is for real–marijuana is a perfect symbol for how we’ve been institutionalized in this country to believe something harmless is bad.
From  LasVegasCityLife:
For a plant that’s never caused a single human death in the tens of thousands of years it’s been with us, marijuana still faces a gargantuan social stigma.
Government propagandists and some social conservatives, in their quest to proscribe our behavior, and consumption, are quick to cite anecdotal evidence and piles of bogus liquor- and prescription-drug-industry-funded studies that warn of the dangers of firing up even that first joint.
Yet these crusaders invariably fail to cite a little thing we call the truth: That alcohol, tobacco and prescription drugs kill or maim hundreds of thousands of Americans each year while marijuana kills, oh, no one; that marijuana – still this nation’s leading cash crop, with estimated sales of $35.8 billion in 2006 – was legal in this country until almost 1940 (long after Prohibition had come and gone); that legalizing, and taxing, the sale of a plant that’s been legal for most of our history could help pull state governments, including Nevada’s, out of recent budgetary sink holes; that’s it not the government’s (or anyone else’s) business to tell Americans what they can and cannot put into their own bodies.
Luckily, a growing number of legal, medical and policy experts are changing perceptions through the intellectual and logical force of their arguments that the time has come to re-examine and change our failed drug policies. Policies which will cost us more than $15 billion this fiscal year alone.
Steve Fox, director of State Campaigns for the Marijuana Policy Project (the nation’s largest organization dedicated to reforming marijuana laws) is one such expert. A former congressional lobbyist and a longtime proponent of sanity in public policy, Fox recently spent some time with CityLife talking about his new book Marijuana is Safer and to hash out and contrast the relative harms, and legal status, of this nation’s two most popular recreational substances: alcohol and marijuana.
CityLife: Considering the growth of the medical marijuana movement, especially here in the American West, and an increasing number of government and university studies that show alcohol to be far more dangerous that marijuana, do you think the United States will join other civilized nations such as The Netherlands and Portugal in re-legalizing cannabis?
Fox: It’s seeming like the writing is on the wall, but that doesn’t mean we’re as close as we’d like to be. There are, obviously, decades of propaganda and myth out there that have the ability to stall reform. It will be a battle, in the end, to change things.
The good news is that coffee is finally back in good graces because it has been proven to have numerous health benefits that have just recently been discovered. Coffee, for the past several decades, has definitely gotten a bad rap because it was in a number of studies citing that it had bad health effects, when many of the participants in the studies were actually smokers so the results were skewed.
Right now, as you enjoy your daily cup of Joe, you can also rest assured that you are drinking a natural source of antioxidants, from the findings in a study by the University of Scranton. And what do antioxidants provide for your health? I am sure that you have heard how important it is to drink green tea and a glass of wine for all of the antioxidant benefits, but now recent news and media sources like MSNBC have proclaimed that coffee is actually one of the main beneficiaries of antioxidants for Americans.
The reason behind this is that it is the number one drink of choice by all Americans, so this is where you are all getting your antioxidant intake from. Antioxidants actually work to counteract the damage from free radicals in your body which can harm your cells and cause premature aging, as well as disease. It is completely comforting to know that as you are sipping your Java every day, you are also working to protect your body as a whole.
To conclude, I have to tell you that one of the most eco-friendly and delicious ways to enjoy your daily coffee drink is by using a French Press. This is actually a wonderful and natural way to enjoy your brew because there are no filters being used or discarded, and all you have to do is freshly grind your beans and steep them in boiling water to have a steaming cup of coffee in minutes!
My personal favorite is the Bodum 3 cup French Press, which is a personal size and completely convenient to use in your home or office. Regardless of the way that you choose to enjoy your Java, just know that it is a natural beverage that provides an astounding number of health benefits. I’ll drink to that!
This has been a guest post by Bethany North. Way to go green blog does not imply any medical or health benefits other than the personal opinion of Ms. North. Thank you Bethany for the nice article. Who doesn’t like a great cup of coffee?
People often wonder what is the deadliest creature on the planet and argue about which animal should take that spot. To be honest though, none deserve that crowning glory better than us humans. But that set aside, let us take a quick look at the supposedly deadliest animals on the planet rated based on their danger to humans as the main criteria.
10. Poison dart frog
The natives just run darts against the skin of this tiny, bright and colorful frog from the rainforests of South America to hunt down prey. Why? Because its poison is enough to kill ten men and will be triggered the moment you touch its skin.
9. Cape buffalo
Here is a simple lesson if and when hunting the cape buffalo- Do not hurt it and leave it wounded as it will actively chase and kill you. This aggressive and massive animal kills more people in Africa than even the mighty predators prowling the continent.
8. Polar bear
The largest predator on the planet is ultra-protective when it comes to its young cubs. And when over-enthusiastic tourists or locals get too close to the cuddly, cute cubs, they are just inviting the wrath of the polar behemoth.
7. The elephant
They are not always the gentle giants and when in rampaging mood, a herd can mow down anything in its path. Reason for over 600 deaths every year, if you manage to keep out of the path then you are safe.
6. African lion
This seems a tab bit strange considering the fact that you would be careful enough to keep your way out of the Jungle king. But in nations like Tanzania where around 70 humans each year fall prey to the lion, that border between civilization and the African Savannah is thin and blurred.
5. Great white shark
With 30 to 100 global deaths each year, the great white is a predator that is all too well known and well documented. It is said that once it gets a taste of human flesh, it will develop a taste for further kills. The ocean’s most well-oiled and evolved killing machine strikes fear at sight.
4. Australian box jellyfish
With 5,567 deaths since 1884, that will definitely speak volumes about how lethal these creatures are. The most venomous marine creature known to man, each tentacle has enough toxins to kill 60 people. Beware if you’re swimming on the Australian coasts.
3. Australian saltwater crocodile
The famous ‘death roll’ will ensure that once you step into the water, it will drown you and then tear you apart. Water is its domain and the largest living reptile on the planet brings with it the ferocity of its Jurassic heritage causing around 2000 causalities each year.
2. Asian Cobra
Snakes like the Resells Viper and the Black Mamba might be deadlier, but the fact that the populous Asian continent is the home to the King Cobra makes its run-ins with humans all too regular and causalities aplenty.
A small bite that can turn out to be deadly with malaria infecting and killing millions of people across the globe each year. With majority of the victims residing in the developing nations and in the tropical belt, this tiny creature is the biggest killer of them all.
Fri, Apr 04 2009Researchers in Spain have found out that the main chemical in marijuana appears to be helpful in the destruction of brain cancer cells.
The active component of marijuana, tetrahydrocannabinol (THC), causes cancer cells to undergo a process called autophagy – the breakdown that occurs when the cell essentially self-digests, according to a new study released on Thursday.
The authors from the Complutense University in Madrid conducted the study with scientists from other universities, AFP reported. The research indicates that THC and related “cannabinoids” appear to be “a new family of potential antitumoral agent.”
The authors wrote that the chemical may prove useful in the development of future “antitumoral agents.”
The scientists conducted their research on mice, first stimulating the growth of cancer in the lab animals, then injecting them with a daily dose of THC near the site of their tumors.
The researchers also analyzed the tumors of two patients in an experimental trial looking at the effects of THC on a highly aggressive form of brain tumor, and saw findings “in line with the preclinical evidence” first observed in the laboratory mice.