Medical Tests


The devastation wrought by the worst recorded Ebola outbreak in history grows daily. As of Thursday, the deaths totalled 729 deaths in West Africa, according to the World Health Organization (WHO), but it’s far from over; ”Ebola is worsening in West Africa,” CDC director Tom Frieden said not once, or twice, but three times on Thursday.

Infectious disease experts are mobilizing, borders are shutting down, and, despite the fact that there is no cure for Ebola haemorrhagic fever (the illness caused by Ebola virus infection), health care officials are trying anything they can to help the stricken—especially those who put themselves at risk to save others. That means digging deep into the list of experimental methods the WHO, CDC and others have developed over the past few years to cure the deadly viral infection—including a simple but controversial therapy called immune plasma infusion.

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In Monrovia, Liberia, 33-year old Dr. Kent Brantly of Forth Worth, Texas had been treating Ebola patients since June, as part of an international relief group called Samaritan’s Purse. But in mid-July, Brantly recognized that he himself was showing symptoms of Ebola. He isolated himself, and told the rest of the team of his suspicions; soon after, his diagnosis was confirmed.

On Thursday Brantly was given a shot at survival: a 14-year-old male Ebola patient who had been under Brantly’s care, and survived, donated a “unit of blood” to Brantly, according to Samaritan’s Purse President Franklin Graham. “The young boy and his family wanted to be able to help the doctor that saved his life.”

The idea—novel, though not unprecedented—is that the blood (plasma, in medical parlance) of a survivor, full of antibodies proven to be strong enough to fight off the disease (i.e., immune), when transfused into an infected body, might help that body become immune itself. Though it sounds a bit like something Hollywood might have cooked up, there’s some science behind it—and an historical precedent that offers hope.

By the time Robert Colebunders arrived in Kikwit, Democratic Republic of Congo (known as Zaire at the time), on June 15 of 1995, the Ebola virus had ravaged the city of 250,000 and the neighboring area for nearly 6 months. The hospitals in the riverport town were empty; patients and healthcare workers had fled to other parts of the country for fear of contracting the deadly disease, which would ultimately affect 317 people and kill 245.

Eventually, the Kikwit Ebola outbreak was traced back to January 1995, but it wasn’t until the start of May of that year that local public health officials recognized the many sick patients in the area as victims of the infectious disease. On May 8th, the Zairian government officially declared the epidemic, asking the World Health Organization to mobilize international assistance. Soon after, infectious disease experts arrived from the WHO, the CDC, Doctors Without Borders, the South African Medical Institute, the Red Cross, and Belgium’s Institute of Tropical Medicine—which sent Colebunders.

Immediately, the team went to work to contain the disease.

“We rapidly began talking to local leaders, quickly helping create an understanding in the population that an intervention was needed,” says Colebunders. The team established a surveillance network to identify and isolate patients who were suspected to have Ebola, and distributed protective equipment that gave local health care workers the ability—and the confidence—to safely work with the infected.

“We buried the dead bodies ourselves,” says Colebunders, working with Red Cross volunteers. Not just the known Ebola victims, either; every dead body in the area. The traditional burial rituals in the area involve family members cleaning the dead body, mourners coming to touch and kiss the body, and even keeping hair and nail as souvenirs. “If its not done in the right way, they think the ghost of the person will do them some harm,” says Colebunders. They had to convince them to put the bodies in plastic bags, a hard sell anywhere. “Putting your loved one in a plastic body bag is really not acceptable. That’s for your trash,” Colebunders says. “You need to help them understand.”

It worked: soon enough, reports of newly infected patients petered out. They were near declaring victory.

Then, in the last days, a nurse at Kikwit General Hospital, who had volunteered to care for a pair of Ebola-infected Italian nuns, developed symptoms of Ebola hemorrhagic fever.

“The rest of the team became concerned,” says Colebunders, and some of the medical professionals there who had suffered through and survived an earlier infection (“convalescent patients” in the literature) wanted to donate some of their blood to the nurse. “The Americans and Scientists from the States didnt believe it could work,” says Colebunders, but the Congolese doctors did it anyway. The same blood transfusion procedure was repeated for seven others who were ill, the final group of Ebola-stricken patients in the hospital.

The results were staggering: seven of the eight survived.

Typically, Ebola is almost unbelievably deadly, historically killing almost 90 percent of those it infects. It’s “very dramatic and even preternatural,” says David Quammen, a journalist and author of Spillover, a book documenting the impact of zoonotic diseases like Ebola. “It kills people quickly and it kills a high proportion of the people it infects.” The Kikwit case study (which would go on to be published in the Journal of Infectious Diseases) showed an almost 90 percent survival rate.

There’s precedent for this treatment approach, too. “We use this in other infectious diseases, and we can—and should—use that experience and apply it to Ebola,” says Heinrich Feldmann, the head of the National Institute of Health’s Laboratory of Virology. In Argentina, for example, infection of the Junin virus is often (and effectively) treated with blood transfusions from a Junin survivor.

So, why hasn’t the CDC, the WHO and the rest of the public health organizations worldwide jumped all over immune plasma infusion for Ebola? Why are we still scrambling for an Ebola treatment 20 years later?

The answer is that it has been essentially impossible to test. Why? Because Ebola only pops up occasionally, infects a relative few, and kills most. There’s no way, says Feldmann, to get enough plasma during an outbreak to treat others involved in that same outbreak. “Of course if you are collecting plasma now for the next outbreak, then you will have the time to do it,” Feldmann adds, though he is unaware of anyone collecting plasma during the current West African outbreak.

At least, until the unnamed 14-year-old boy, who, of his own accord, is about to become a key piece of the second test case in 20 years for what could be the treatment we’ve all been waiting for.

“We clearly need more effective ways to treat these patients and to protect health care workers,” says Colebunders. “Confronted with such a deadly disease, it is time to consider the use of experimental vaccines and treatments as compassionate use.”

* By  , 8/1/14 (Newsweek)

A Boyle Heights farmers market for medical marijuana users has been temporarily shut down by a Los Angeles County Superior Court judge.

The judge’s ruling Tuesday grants a temporary restraining order sought by Los Angeles City Atty. Mike Feuer to stop the California Heritage Market operations, saying it failed to comply with the city’s voter-approved law regulating marijuana dispensaries.

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“The bottom line is that we argued successfully that this so-called farmers market was an attempt to make an end-run around the will of the people,” Feuer said. “The court saw through this subterfuge.”

Los Angeles voters passed Proposition D last year, establishing legal parameters under which marijuana dispensaries could do business in the city.

The court’s ruling, Feuer said, supports the “spirit and the letter of Proposition D.”

The cannabis market opened to a booming business over the Fourth of July weekend, attracting hundreds of customers and an array of growers offering marijuana buds with airy names such as Blue Dream and Banana Kush along with marijuana-infused balms, sunblock, lollipops, tea and even a waffle mix.

Customers, who were required to show their IDs and prove they could legally buy pot, said they appreciated being able to cut the “middleman” out of the equation and buy their product at a discount straight from the growers.

Jamie Brown of First Choice Farms said he found the marketplace to be “absolute genius,” a place where customers could find out about different strains of marijuana.

But the temporary injunction issued Tuesday halts all that for now by restricting the market’s operators from setting up booths and advertising it, according to legal documents. Police and fire officials must also be granted access to the site.

“The court was very clear: There could be no multiple vendors selling at this site, only bona fide employees,” Feuer said.

The market — which attracted both old and young, tattooed and clean-cut — was held over the Fourth of July weekend in a warehouse directly behind the West Coast Collective dispensary in an industrial zone in Boyle Heights.

The following weekend, the market opened again.

Proposition D, Feuer said, does not allow multiple, independent vendors to sell on one site.

“That’s essentially what this business model was,” Feuer said.

But attorney David Welch, who represents the Progressive Horizon collective, said Feuer’s argument doesn’t make sense.

He said a farmers market is no different from a dispensary in that they both sell goods from a variety of vendors.

“Their arguments are basically a misunderstanding on how this business operates,” he said.

The city’s actions, Welch said, were essentially proving that “you can’t actually open a marijuana dispensary” in Los Angeles.

A hearing is scheduled Aug. 6 to determine whether the market will be permanently closed.

 

* Veronica Rocha, latimes, July 15, 2014

Rep. Trey Radel, a Florida Republican elected in 2012, will be in court Wednesday on charges that he possessed cocaine.

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Radel, 37, was charged with misdemeanor possession of cocaine in D.C. Superior Court on Tuesday.

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He faces a maximum of 180 days in jail, as well as a fine of up to $1,000. Several sources with direct knowledge say it was the FBI and Drug Enforcement Administration who were involved in the charges.

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Radel has missed all four votes in the House this week.

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Radel, in a statement released by his office, made no mention of resigning from the House. He said he struggles “with the disease of alcoholism, and this led to an extremely irresponsible choice. As the father of a young son and a husband to a loving wife, I need to get help so I can be a better man for both of them.”

A spokesman for Speaker John Boehner (R-Ohio) said, “Members of Congress should be held to the highest standards, and the alleged crime will be handled by the courts. Beyond that, this is between Rep. Radel, his family, and his constituents.”

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The U.S. Attorney’s office for the District of Columbia declined to comment on Radel’s arrest and case.

The Associated Press, citing an unnamed DEA official, said Radel allegedly bought cocaine from a dealer in the Dupont Circle area who had been previously arrested as part of a federal probe. “Later that night, federal authorities went to his apartment and informed him that he would be facing criminal charges related to his purchase of cocaine,” the AP said.

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The Florida Republican, who holds a district on the western coast of Florida that includes the tony Marco Island, is a former journalist, TV anchor and radio talk-show host. He never held elective office before winning his House seat last November. His district was vacated by former Rep. Connie Mack (R-Fla.), who ran for the Senate.

In the statement, Radel said he realizes “the disappointment my family, friends and constituents must feel. Believe me, I am disappointed in myself, and I stand ready to face the consequences of my actions.”

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The arrest, he said, has a “positive side.”

“It offers me an opportunity to seek treatment and counseling,” he said. “I know I have a problem and will do whatever is necessary to overcome it, hopefully setting an example for others struggling with this disease.”

Text by John Bresnahan and Jake Sherman (Politico), 11/19/2013

Many people hit the gym or pound the pavement to improve cardiovascular health, build muscle, and of course, get a rockin’ bod, but working out has above-the-neck benefits, too. For the past decade or so, scientists have pondered how exercising can boost brain function. Regardless of age or fitness level (yup, this includes everyone from mall-walkers to marathoners), studies show that making time for exercise provides some serious mental benefits. Get inspired to exercise by reading up on these unexpected ways that working out can benefit mental health, relationships and lead to a healthier and happier life overall.

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1. Reduce Stress 

Rough day at the office? Take a walk or head to the gym for a quick workout. One of the most common mental benefits of exercise is stress relief. Working up a sweat can help manage physical and mental stress. Exercise also increases concentrations of norepinephrine, a chemical that can moderate the brain’s response to stress. So go ahead and get sweaty — working out can reduce stress and boost the body’s ability to deal with existing mental tension. Win-win!

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2. Boost Happy Chemicals
Slogging through a few miles on the ‘mill can be tough, but it’s worth the effort! Exercise releases endorphins, which create feelings of happiness and euphoria. Studies have shown that exercise can even alleviate symptoms among the clinically depressed. For this reason, docs recommend that people suffering from depression or anxiety (or those who are just feeling blue) pencil in plenty of gym time. In some cases, exercise can be just as effective as antidepressant pills in treating depression. Don’t worry if you’re not exactly the gym rat type — getting a happy buzz from working out for just 30 minutes a few times a week can instantly boost overall mood.

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3. Improve Self-Confidence
Hop on the treadmill to look (and more importantly, feel) like a million bucks. On a very basic level, physical fitness can boost self-esteem and improve positive self-image. Regardless of weight, size, gender or age, exercise can quickly elevate a person’s perception of his or her attractiveness, that is, self-worth. How’s that for feeling the (self) love?

4. Enjoy The Great Outdoors
For an extra boost of self-love, take that workout outside. Exercising in the great outdoors can increase self-esteem even more. Find an outdoor workout that fits your style, whether it’s rock-climbing, hiking, renting a canoe or just taking a jog in the park. Plus, all that Vitamin D acquired from soaking up the sun (while wearing sunscreen, of course!) can lessen the likelihood of experiencing depressive symptoms. Why book a spa day when a little fresh air and sunshine (and exercise) can work wonders for self-confidence and happiness?

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5. Prevent Cognitive Decline

It’s unpleasant, but it’s true — as we get older, our brains get a little… hazy. As aging and degenerative diseases like Alzheimer’s kill off brain cells, the noggin actually shrinks, losing many important brain functions in the process. While exercise and a healthy diet can’t “cure” Alzheimer’s, they can help shore up the brain against cognitive decline that begins after age 45 Working out, especially between age 25 and 45, boosts the chemicals in the brain that support and prevent degeneration of the hippocampus, an important part of the brain for memory and learning.

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6. Alleviate Anxiety
Quick Q&A: Which is better at relieving anxiety — a warm bubble bath or a 20-minute jog? You might be surprised at the answer. The warm and fuzzy chemicals that are released during and after exercise can help people with anxiety disorders calm down. Hopping on the track or treadmill for some moderate-to-high intensity aerobic exercise (intervals, anyone?) can reduce anxiety sensitivity. And we thought intervals were just a good way to burn calories!

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7. Boost Brainpower
Those buff lab rats might be smarter than we think. Various studies on mice and men have shown that cardiovascular exercise can create new brain cells (akaneurogenesis) and improve overall brain performance. Ready to apply for a Nobel Prize? Studies suggest that a tough workout increases levels of a brain-derived protein (known as BDNF) in the body, believed to help with decision making, higher thinking and learning. Smarty (spandex) pants, indeed.

8. Sharpen Memory
Get ready to win big at Go Fish. Regular physical activity boosts memory and ability to learn new things. Getting sweaty increases production of cells in hippocampusresponsible for memory and learning. For this reason, research has linked children’sbrain development with level of physical fitness (take that, recess haters!). But exercise-based brainpower isn’t just for kids. Even if it’s not as fun as a game of Red Rover, working out can boost memory among grown-ups, too. A study showed thatrunning sprints improved vocabulary retention among healthy adults.

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9. Help Control Addiction
The brain releases dopamine, the “reward chemical” in response to any form of pleasure, be that exercise, sex, drugs, alcohol or food. Unfortunately, some people become addicted to dopamine and dependent on the substances that produce it, like drugs or alcohol (and more rarely, food and sex). On the bright side, exercise can help in addiction recovery. Short exercise sessions can also effectively distract drug oralcohol addicts, making them de-prioritize cravings (at least in the short term). Working out when on the wagon has other benefits, too. Alcohol abuse disrupts many body processes, including circadian rhythms. As a result, alcoholics find they can’t fall asleep (or stay asleep) without drinking. Exercise can help reboot the body clock, helping people hit the hay at the right time.

10. Increase Relaxation
Ever hit the hay after a long run or weight session at the gym? For some, a moderate workout can be the equivalent of a sleeping pilleven for people with insomnia. Moving around five to six hours before bedtime raises the body’s core temperature. When the body temp drops back to normal a few hours later, it signals the body that it’s time to sleep.

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11. Get More Done
Feeling uninspired in the cubicle? The solution might be just a short walk or jog away. Research shows that workers who take time for exercise on a regular basis are more productive and have more energy than their more sedentary peers. While busy schedules can make it tough to squeeze in a gym session in the middle of the day, some experts believe that midday is the ideal time for a workout due to the body’scircadian rhythms.

12. Tap Into Creativity
Most people end a tough workout with a hot shower, but maybe we should be breaking out the colored pencils instead. A heart-pumping gym session can boost creativity for up to two hours afterwards. Supercharge post-workout inspiration by exercising outdoors and interacting with nature (see benefit #4). Next time you need a burst of creative thinking, hit the trails for a long walk or run to refresh the body and the brain at the same time.

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13. Inspire Others
Whether it’s a pick-up game of soccer, a group class at the gym, or just a run with a friend, exercise rarely happens in a bubble. And that’s good news for all of us. Studies show that most people perform better on aerobic tests when paired up with a workout buddy. Pin it to inspiration or good old-fashioned competition, nobody wants to let the other person down. In fact, being part of a team is so powerful that it can actuallyraise athletes’ tolerances for pain. Even fitness beginners can inspire each other to push harder during a sweat session, so find a workout buddy and get moving!

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Working out can have positive effects far beyond the gym (and beach season). Gaining self-confidence, getting out of a funk, and even thinking smarter are some of the motivations to take time for exercise on a regular basis.

 

* Text by Sophia Breene, Huff Post (3/27/2013)

Our brains are better than Google or the best robot from iRobot.

We can instantly search through a vast wealth of experiences and emotions. We can immediately recognize the face of a parent, spouse, friend or pet, whether in daylight, darkness, from above or sideways—a task that the computer vision system built into the most sophisticated robots can accomplish only haltingly. We can also multitask effortlessly when we extract a handkerchief from a pocket and mop our brow while striking up a conversation with an acquaintance. Yet designing an electronic brain that would allow a robot to perform this simple combination of behaviors remains a distant prospect.

How does the brain pull all this off, given that the complexity of the networks inside our skull—trillions of connections among billions of brain cells—rivals that of theInternet? One answer is energy efficiency: when a nerve cell communicates with another, the brain uses just a millionth of the energy that a digital computer expends to perform the equivalent operation. Evolution, in fact, may have played an important role in pushing the three-pound organ toward ever greater energy efficiencies.

Parsimonious energy consumption cannot be the full explanation, though, given that the brain also comes with many built-in limitations. One neuron in the cerebral cortex, for instance, can respond to an input from another neuron by firing an impulse, or a “spike,” in thousandths of a second—a snail’s pace compared with the transistors that serve as switches in computers, which take billionths of a second to switch on. The reliability of the neuronal network is also low: a signal traveling from one cortical cell to another typically has only a 20 percent possibility of arriving at its ultimate destination and much less of a chance of reaching a distant neuron to which it is not directly connected.

Neuroscientists do not fully understand how the brain manages to extract meaningful information from all the signaling that goes on within it. The two of us and others, however, have recently made exciting progress by focusing new attention on how the brain can efficiently use the timing of spikes to encode information and rapidly solve difficult computational problems. This is because a group of spikes that fire almost at the same moment can carry much more information than can a comparably sized group that activates in an unsynchronized fashion.

Beyond offering insight into the most complex known machine in the universe, further advances in this research could lead to entirely new kinds of computers. Already scientists have built “neuromorphic” electronic circuits that mimic aspects of the brain’s signaling network. We can build devices today with a million electronic neurons, and much larger systems are planned. Ultimately investigators should be able to build neuromorphic computers that function much faster than modern computers but require just a fraction of the power [see “Neuromorphic Microchips,” by Kwabena Boahen; Scientific American, May 2005].

Cell Chatter

Like many other neuroscientists, we often use the visual system as our test bed, in part because its basic wiring diagram is well understood. Timing of signals there and elsewhere in the brain has long been suspected of being a key part of the code that the brain uses to decide whether information passing through the network is meaningful. Yet for many decades these ideas were neglected because timing is only important when compared between different parts of the brain, and it was hard to measure activity of more than one neuron at a time. Recently, however, the practical development of computer models of the nervous system and new results from experimental and theoretical neuroscience have spurred interest in timing as a way to better understand how neurons talk to one another.

Brain cells receive all kinds of inputs on different timescales. The microsecond-quick signal from the right ear must be reconciled with the slightly out-of-sync input from the left. These rapid responses contrast with the sluggish stream of hormones coursing through the bloodstream. The signals most important for this discussion, though, are the spikes, which are sharp rises in voltage that course through and between neurons. For cell-to-cell communication, spikes lasting a few milliseconds handle immediate needs. A neuron fires a spike after deciding that the number of inputs urging it to switch on outweigh the number telling it to turn off. When the decision is made, a spike travels down the cell’s axon (somewhat akin to a branched electrical wire) to its tips. Then the signal is relayed chemically through junctions, called synapses, that link the axon with recipient neurons.

In each eye, 100 million photoreceptors in the retina respond to changing patterns of light. After the incoming light is processed by several layers of neurons, a million ganglion cells at the back of the retina convert these signals into a sequence of spikes that are relayed by axons to other parts of the brain, which in turn send spikes to still other regions that ultimately give rise to a conscious perception. Each axon can carry up to several hundred spikes each second, though more often just a few spikes course along the neural wiring. All that you perceive of the visual world—the shapes, colors and movements of everything around you—is coded into these rivers of spikes with varying time intervals separating them.

Monitoring the activity of many individual neurons at once is critical for making sense of what goes on in the brain but has long been extremely challenging. In 2010, though, E. J. Chichilnisky of the Salk Institute for Biological Studies in La Jolla, Calif., and his colleagues reported in Nature that they had achieved the monumental task of simultaneously recording all the spikes from hundreds of neighboring ganglion cells in monkey retinas. (Scientific American is part of Nature Publishing Group.) This achievement made it possible to trace the specific photoreceptors that fed into each ganglion cell. The growing ability to record spikes from many neurons simultaneously will assist in deciphering meaning from these codelike brain signals.

For years investigators have used several methods to interpret, or decode, the meaning in the stream of spikes coming from the retina. One method counts spikes from each axon separately over some period: the higher the firing rate, the stronger the signal. The information conveyed by a variable firing rate, a rate code, relays features of visual images, such as location in space, regions of differing light contrast, and where motion occurs, with each of these features represented by a given group of neurons.

Information is also transmitted by relative timing—when one neuron fires in close relation to when another cell spikes. Ganglion cells in the retina, for instance, are exquisitely sensitive to light intensity and can respond to a changing visual scene by transmitting spikes to other parts of the brain. When multiple ganglion cells fire at almost the same instant, the brain suspects that they are responding to an aspect of the same physical object. Horace Barlow, a leading neuroscientist at the University of Cambridge, characterized this phenomenon as a set of “suspicious coincidences.” Barlow referred to the observation that each cell in the visual cortex may be activated by a specific physical feature of an object (say, its color or its orientation within a scene). When several of these cells switch on at the same time, their combined activation constitutes a suspicious coincidence because it may only occur at a specific time for a unique object. Apparently the brain takes such synchrony to mean that the signals are worth noting because the odds of such coordination occurring by chance are slim.

 

Electrical engineers are trying to build on this knowledge to create more efficient hardware that incorporates the principles of spike timing when recording visual scenes. One of us (Delbruck) has built a camera that emits spikes in response to changes in a scene’s brightness, which enables the tracking of very fast moving objects with minimal processing by the hardware to capture images [see box above].

Into the Cortex

New evidence adds proof that the visual cortex attends to temporal clues to make sense of what the eye sees. The ganglion cells in the retina do not project directly to the cortex but relay signals through neurons in the thalamus, deep within the brain’s midsection. This region in turn must activate 100 million cells in the visual cortex in each hemisphere at the back of the brain before the messages are sent to higher brain areas for conscious interpretation.

We can learn something about which spike patterns are most effective in turning on cells in the visual cortex by examining the connections from relay neurons in the thalamus to cells known as spiny stellate neurons in a middle layer of the visual cortex. In 1994 Kevan Martin, now at the Institute of Neuroinformatics at the University of Zurich, and his colleagues reconstructed the thalamic inputs to the cortex and found that they account for only 6 percent of all the synapses on each spiny stellate cell. How, then, everyone wondered, does this relatively weak visual input, a mere trickle, manage to reliably communicate with neurons in all layers of the cortex?

Cortical neurons are exquisitely sensitive to fluctuating inputs and can respond to them by emitting a spike in a matter of a few milliseconds. In 2010 one of us (Sejnowski), along with Hsi-Ping Wang and Donald Spencer of the Salk Institute and Jean-Marc Fellous of the University of Arizona, developed a detailed computer model of a spiny stellate cell and showed that even though a single spike from only one axon cannot cause one of these cells to fire, the same neuron will respond reliably to inputs from as few as four axons projecting from the thalamus if the spikes from all four arrive within a few milliseconds of one another. Once inputs arrive from the thalamus, only a sparse subset of the neurons in the visual cortex needs to fire to represent the outline and texture of an object. Each spiny stellate neuron has a preferred visual stimulus from the eye that produces a high firing rate, such as the edge of an object with a particular angle of orientation.

In the 1960s David Hubel of Harvard Medical School and Torsten Wiesel, now at the Rockefeller University, discovered that each neuron in the relevant section of the cortex responds strongly to its preferred stimulus only if activation comes from a specific part of the visual field called the neuron’s receptive field. Neurons responding to stimulation in the fovea, the central region of the retina, have the smallest receptive fields—about the size of the letter e on this page. Think of them as looking at the world through soda straws. In the 1980s John Allman of the California Institute of Technology showed that visual stimulation from outside the receptive field of a neuron can alter its firing rate in reaction to inputs from within its receptive field. This “surround” input puts the feature that a neuron responds to into the context of the broader visual environment.

Stimulating the region surrounding a neuron’s receptive field also has a dramatic effect on the precision of spike timing. David McCormick, James Mazer and their colleagues at Yale University recently recorded the responses of single neurons in the cat visual cortex to a movie that was replayed many times. When they narrowed the movie image so that neurons triggered by inputs from the receptive field fired (no input came from the surrounding area), the timing of the signals from these neurons had a randomly varying and imprecise pattern. When they expanded the movie to cover the surrounding area outside the receptive field, the firing rate of each neuron decreased, but the spikes were precisely timed.

 

The timing of spikes also matters for other neural processes. Some evidence suggests that synchronized timing—with each spike representing one aspect of an object (color or orientation)—functions as a means of assembling an image from component parts. A spike for “pinkish red” fires in synchrony with one for “round contour,” enabling the visual cortex to merge these signals into the recognizable image of a flower pot.

Attention and Memory

Our story so far has tracked visual processing from the photoreceptors to the cortex. But still more goes into forming a perception of a scene. The activity of cortical neurons that receive visual input is influenced not only by those inputs but also by excitatory and inhibitory interactions between cortical neurons. Of particular importance for coordinating the many neurons responsible for forming a visual perception is the spontaneous, rhythmic firing of a large number of widely separated cortical neurons at frequencies below 100 hertz.

Attention—a central facet of cognition—may also have its physical underpinnings in sequences of synchronized spikes. It appears that such synchrony acts to emphasize the importance of a particular perception or memory passing through conscious awareness. Robert Desimone, now at the Massachusetts Institute of Technology, and his colleagues have shown that when monkeys pay attention to a given stimulus, the number of cortical neurons that fire synchronized spikes in the gamma band of frequencies (30 to 80 hertz) increases, and the rate at which they fire rises as well. Pascal Fries of the Ernst Strüngmann Institute for Neuroscience in cooperation with the Max Planck Society in Frankfurt found evidence for gamma-band signaling between distant cortical areas.

Neural activation of the gamma-frequency band has also attracted the attention of researchers who have found that patients with schizophrenia and autism show decreased levels of this type of signaling on electroencephalographic recordings. David Lewis of the University of Pittsburgh, Margarita Behrens of the Salk Institute and others have traced this deficit to a type of cortical neuron called a basket cell, which is involved in synchronizing spikes in nearby circuits. An imbalance of either inhibition or excitation of the basket cells seems to reduce synchronized activity in the gamma band and may thus explain some of the physiological underpinnings of these neurological disorders. Interestingly, patients with schizophrenia do not perceive some visual illusions, such as the tilt illusion, in which a person typically misjudges the tilt of a line because of the tilt of nearby lines. Similar circuit abnormalities in the prefrontal cortex may be responsible for the thought disorders that accompany schizophrenia.

When it comes to laying down memories, the relative timing of spikes seems to be as important as the rate of firing. In particular, the synchronized firing of spikes in the cortex is important for increasing the strengths of synapses—an important process in forming long-term memories. A synapse is said to be strengthened when the firing of a neuron on one side of a synapse leads the neuron on the other side of the synapse to register a stronger response. In 1997 Henry Markram and Bert Sakmann, then at the Max Plank Institute for Medical Research in Heidelberg, discovered a strengthening process known as spike-timing-dependent plasticity, in which an input at a synapse is delivered at a frequency in the gamma range and is consistently followed within 10 milliseconds by a spike from the neuron on the other side of the synapse, a pattern that leads to enhanced firing by the neuron receiving the stimulation. Conversely, if the neuron on the other side fires within 10 milliseconds before the first one, the strength of the synapse between the cells decreases.

Some of the strongest evidence that synchronous spikes may be important for memory comes from research by György Buzsáki of New York University and others on the hippocampus, a brain area that is important for remembering objects and events. The spiking of neurons in the hippocampus and the cortical areas that it interacts with is strongly influenced by synchronous oscillations of brain waves in a range of frequencies from four to eight hertz (the theta band), the type of neural activity encountered, for instance, when a rat is exploring its cage in a laboratory experiment. These theta-band oscillations can coordinate the timing of spikes and also have a more permanent effect in the synapses, which results in long-term changes in the firing of neurons.

 

A Grand Challenge Ahead

Neuroscience is at a turning point as new methods for simultaneously recording spikes in thousands of neurons help to reveal key patterns in spike timing and produce massive databases for researchers. Also, optogenetics—a technique for turning on genetically engineered neurons using light—can selectively activate or silence neurons in the cortex, an essential step in establishing how neural signals control behavior. Together, these and other techniques will help us eavesdrop on neurons in the brain and learn more and more about the secret code that the brain uses to talk to itself. When we decipher the code, we will not only achieve an understanding of the brain’s communication system, we will also start building machines that emulate the efficiency of this remarkable organ.

 

* By Terry Sejnowski and Tobi Delbruck  

ABOUT THE AUTHOR(S)

Terry Sejnowski is an investigator with the Howard Hughes Medical Institute and is Francis Crick Professor at the Salk Institute for Biological Studies, where he directs the Computational Neurobiology Laboratory.

Tobi Delbruck is co-leader of the sensors group at the Institute of Neuroinformatics at the University of Zurich.

 MORE TO EXPLORE

Terry Sejnowski’s 2008 Wolfgang Pauli Lectures on how neurons compute and communicate: www.podcast.ethz.ch/podcast/episodes/?id=607

Neuromorphic Sensory Systems. Shih-Chii Liu and Tobi Delbruck in Current Opinion in Neurobiology, Vol. 20, No. 3, pages 288–295; June 2010. http://tinyurl.com/bot7ag8

SCIENTIFIC AMERICAN ONLINE
Watch a video about a motion-sensing video camera that uses spikes for imaging at ScientificAmerican.com/oct2012/dvs

Capt. Susan Carlson was not a typical recruit when she volunteered for the Army in 2006 at the age of 50. But the Army desperately needed behavioral health professionals like her, so it signed her up.

Though she was, by her own account, “not a strong soldier,” she received excellent job reviews at Fort Leavenworth, Kan., where she counseled prisoners. But last year, Captain Carlson, a social worker, was deployed to Afghanistan with the Colorado National Guard and everything fell apart.

After a soldier complained that she had made sexually suggestive remarks, she was suspended from her counseling duties and sent to an Army psychiatrist for evaluation. His findings were shattering: She had, he said in a report, a personality disorder, a diagnosis that the military has used to discharge thousands of troops. She was sent home.

She disputed the diagnosis, but it was not until months later that she found what seemed powerful ammunition buried in her medical file, portions of which she provided to The New York Times. “Her command specifically asks for a diagnosis of a personality disorder,” a document signed by the psychiatrist said.

Veterans’ advocates say Captain Carlson stumbled upon evidence of something they had long suspected but had struggled to prove: that military commanders pressure clinicians to issue unwarranted psychiatric diagnoses to get rid of troops.

“Her records suggest an attempt by her commander to influence medical professionals,” said Michael J. Wishnie, a professor at Yale Law School and director of its Veterans Legal Services Clinic.

Since 2001, the military has discharged at least 31,000 service members because of personality disorder, a family of disorders broadly characterized by inflexible “maladaptive” behavior that can impair performance and relationships.

For years, veterans’ advocates have said that the Pentagon uses the diagnosis to discharge troops because it considers them troublesome or wants to avoid giving them benefits for service-connected injuries. The military considers personality disorder a pre-existing problem that emerges in youth, and as a result, troops given the diagnosis are often administratively discharged without military retirement pay. Some have even been required to repay enlistment bonuses.

By comparison, a diagnosis of post-traumatic stress disorder is usually linked to military service and leads to a medical discharge accompanied by certain benefits.

In recent weeks, questions about whether the Army manipulates psychiatric diagnoses to save money have been raised at Joint Base Lewis-McChord near Tacoma, Wash., where soldiers undergoing medical evaluations before discharge complained that psychiatrists rescinded PTSD diagnoses, leaving the soldiers with diagnoses like personality disorder that did not qualify them for medical discharges.

In a memorandum, an Army ombudsman wrote that a doctor from the base hospital, Madigan Army Medical Center, said that one diagnosis of post-traumatic stress disorder can cost $1.5 million in benefits over a soldier’s lifetime. The doctor also counseled his colleagues to be good stewards of taxpayer money by not “rubber-stamping” such diagnoses.

In the wake of those complaints, the Army has removed the head of Madigan and suspended two doctors at a special forensic psychiatric unit. It has also reviewed the cases of 14 soldiers and reinstituted PTSD diagnoses for 6 of them.

Some senior military officials have raised concerns that PTSD is overdiagnosed. Still, the Defense Department has denied that it uses psychiatric diagnoses either to weed out injured or low-performing troops, or to save money.

“Our goal is to provide the most accurate diagnosis,” said Maria Tolleson, a spokeswoman for the Army Medical Command.

On Captain Carlson’s case, the Colorado National Guard declined to comment. Officials at Womack Army Medical Center at Fort Bragg, N.C., said the psychiatrist who evaluated Captain Carlson in Afghanistan, Maj. Aniceto Navarro, was not available for an interview.

But in a statement, the hospital said: “No commander may order a credentialed clinician to make a particular diagnosis. Dr. Navarro did not feel he was being ordered by the service member’s command to make a particular diagnosis. The sentence referenced was written in terms of the commander asking to evaluate for a personality disorder, i.e. asking if one existed, not ordering to diagnose a personality disorder.”

Though it is impossible to know how many veterans are disputing their personality disorder discharges, Vietnam Veterans of America, an advocacy group, with help from the Yale veterans legal clinic, has sued the Defense Department seeking records they say will show that thousands of troops have been unfairly discharged for personality or adjustment disorder since 2001.

“We believe that many of the people who received personality disorder discharges were wrongly diagnosed and that in fact they were suffering from PTSD or traumatic brain injury,” said Thomas Berger, executive director of Vietnam Veterans of America’s health council.

Although the number of personality disorder discharges is small relative to the total number of troops who have served since 2001, Congress was concerned enough about the issue to hold hearings in 2007 after reading reports that troops with post-traumatic stress and other combat-related injuries were being discharged for personality disorder.

The Defense Department then tightened its requirements, partly to ensure that troops who had served in combat zones and had PTSD were not discharged for personality disorder. Personality disorder discharges subsequently declined, to 1,078 in 2010 from 4,264 in 2007, data obtained by Vietnam Veterans of America show.

But the Government Accountability Office said in 2010 that the Defense Department had not proved that it was in full compliance with its rules. And Captain Carlson’s case shows that the military continues to issue personality disorder diagnoses in questionable ways, according to veterans’ advocates and her lawyers, Stephen H. Carpenter Jr. and Daniel C. Russ.

Unlike the soldiers at Madigan, Captain Carlson has not been given a diagnosis of PTSD. But the personality disorder diagnosis could complicate her ability get a medical discharge for a back injury and other problems. Perhaps more significant, the diagnosis will be listed on her discharge papers, which employers typically review when they are considering veterans for a job.

“It may have a significant impact on her ability to find employment,” Mr. Carpenter said.

Captain Carlson, now 55, signed up with the Army after a co-worker at a Milwaukee trauma hospital, a surgeon in the National Guard, told her that the Army badly needed therapists and social workers. Intrigued, she got an age waiver and joined through a program that commissions officers based on their specialized training.

At Fort Leavenworth, where she served for three years, supervisors called her “highly talented,” “outstanding” and “a dedicated officer,” according to a 2008 evaluation.

After leaving active duty, Captain Carlson moved to Colorado Springs in 2010 to take a civilian job as a substance abuse counselor at Fort Carson. But she soon learned that the Colorado National Guard, which she had just joined, would deploy to Afghanistan in early 2011. She told her commander she wanted to go.

“I wanted to experience what soldiers experience,” she said in an interview.

But her problems began soon after she arrived in Afghanistan last February. She got lost outside a combat outpost and wore shorts when she should have been in combat uniform. Then a junior enlisted soldier accused her of sexual harassment, citing an off-color remark she made during a game of Scrabble with several soldiers at a combat outpost.

Captain Carlson contends the remark was innocent, but the Army sent her back to Bagram Air Base near Kabul and opened an investigation. A major general eventually gave her a memorandum of reprimand, a potentially career-ending action. But she says it was the psychological evaluation she received at Bagram that upset her the most.

In notes from that evaluation, Dr. Navarro wrote that “it is very difficult to draw absolute conclusions for a personality disorder.” But he noted that her command had asked for the diagnosis and, in his final report dated three days later, Dr. Navarro did just that.

Captain Carlson has “a very dramatic style” and “chronic difficulty in adjusting,” Dr. Navarro wrote in that report, concluding that she had “personality disorder NOS” — not otherwise specified — “with histrionic traits.” He recommended that the Army move swiftly to discharge her if she did not comply with counseling from her commander.

Experts say personality disorder is generally evident in a person’s youth, leaving a telltale pattern across failed jobs and broken relationships. For that reason, they generally recommend that diagnoses include reviews of patients’ medical records and interviews with people who have known them for years. Dr. Navarro says in his notes that he did not have access to her records.

Dr. Andrew E. Skodol, research professor of psychiatry at the University of Arizona and an expert on personality disorder who was not familiar with Captain Carlson’s case, said it would not be surprising for a person who entered the Army in middle age to have trouble adapting to the stresses of military life and deployment. But that would not necessarily qualify as a personality disorder, Dr. Skodol said.

After leaving Afghanistan last year, Captain Carlson went to Joint Base Lewis-McChord, where a psychiatrist gave her a diagnosis of adjustment disorder, her lawyers said. That psychiatrist has since been suspended as part of the Army’s investigation into Madigan.

It will be up to the Colorado National Guard to decide how Captain Carlson will be discharged, a process that could take months. At the least, Captain Carlson wants the personality disorder diagnosis removed from her record.

“It’s a bad label,” she said. “I’m a broken soldier. I’m old. And they just want to get rid of me.”

 

By , NYT, February 24, 2012

 

 

Actor Charlie Sheen, known for his heavy cocaine use, has been stating in interviews that he freed himself of his drug habit. How likely is that?


When asked recently on The Today Showhow he cured himself of his addiction, Two and a Half Men sitcom star Charlie Sheen replied, “I closed my eyes and made it so with the power of my mind.”
Until last month, he was the highest paid actor on TV, despite his well-known bad-boy lifestyle and persistent problems with alcohol and cocaine. After the rest of his season’s shows were canceled by producers, Sheen has gone on an interview tear with many bizarre statements, including that he is on a “winning” streak. His claims of quitting a serious drug habit on his own, however, is perhaps one of his least eccentric statements.

A prevailing view of substance abuse, supported by both the National Institute on Drug Abuse and Alcoholics Anonymous, is the disease model of addiction. The model attributes addiction largely to changes in brain structure and function. Because these changes make it much harder for the addict to control substance use, health experts recommend professional treatment and complete abstinence.

But some in the field point out that many if not most addicts successfully recover without professional help. A survey by Gene Heyman, a research psychologist at McLean Hospital in Massachusetts, found that between 60 to 80 percent of people who were addicted in their teens and 20s were substance-free by their 30s, and they avoided addiction in subsequent decades. Other studies on Vietnam War veteranssuggest that the majority of soldiers who became addicted to narcotics overseas later stopped using them without therapy.

Scientific American spoke with Sally Satel, a resident scholar at the American Enterprise Institute for Public Policy Research and lecturer in psychiatry at the Yale University School of Medicine, about quitting drugs without professional treatment. Satel was formerly a staff psychiatrist at the Oasis Clinic in Washington, D.C., where she worked with substance abuse patients.

[An edited transcript of the interview follows.]

Is it possible to cure yourself of addiction without professional help? How often does that happen?

Of course it’s possible. Most people recover and most people do it on their own. That’s in no way saying that everyone should be expected to quit on their own and in no way denies that quitting is a hard thing to do. This is just an empirical fact. It is even possible that those who quit on their own could have quit earlier if they sought professional help. The implicit message isn’t that treatment isn’t important for many—in fact it should probably be made more accessible—but it is simply a fact that most people cure themselves.

How do addicts stop on their own?

They have to be motivated. It takes the realization that their family, their future, their employment—all these—are becoming severely compromised. The subtext isn’t that they just “walk away” from the addiction. But I’ve had a number of patients in the clinic whose six-year-old says, “Why don’t you ever come to my ball games?” This can prompt a crisis of identity causing the addict to ask himself, “Is this the type of father I want to be?”

If not, there are lots of recovery strategies that users figure out themselves. For example, they change whom they associate with. They can make it harder to access drugs, perhaps by never carrying cash with them. People will put obstacles in front of themselves. True, some people decide they can’t do it on their own and decide to go into treatment—that’s taking matters into one’s own hands, too.


What do professional drug addiction programs offer that is difficult to replicate on one’s own?


If you’re already in treatment, you’ve made a big step. Even for court-ordered treatment, people often internalize the decision as their own. You get a lot of support. You get instruction in formal relapse prevention therapy. You might get methadone for withdrawal and medications for an underlying psychiatric problem.

Most experts regard drug addiction as a brain disease. Do you agree?
I’m critical of the standard view promoted by the National Institute on Drug Abuse that addiction is a brain disease. Naturally, every behavior is mediated by the brain, but the language “brain disease” carries the connotation that the afflicted person is helpless before his own brain chemistry. That is too fatalistic.

It also overlooks the enormously important truth that addicts use drugs to help them cope in some manner. That, as destructive as they are, drugs also serve a purpose. This recognition is very important for designing personalized therapies.


Don’t most studies show that addicts do better with professional help?


People who come to treatment tend to have concurrent psychiatric illness, and they also tend to be less responsive to treatment. Most research is done on people in a treatment program, so by definition you’ve already got a skewed population. This is called the “clinical illusion,” and it applies to all medical conditions. It refers to a tendency to think that the patients you see in a clinical setting fully represent all people with that condition. It’s not true. You’re not seeing the full universe of people.


Based on his public interviews, does it seem likely that Charlie Sheen cured himself?


I doubt it. Of course, I haven’t examined him, but based on what one sees, one would be concerned about ongoing drug use and underlying mental illness.


Is there brain damage from drug use? Is it possible to recover from such damage?


The only drugs that are neurotoxic are alcohol, methamphetamine, probably MDMA [ecstasy], and some inhalants.* Cocaine can lead to micro strokes. That’s brain damage. Yes, addiction changes the brain but this does not doom people to use drugs forever. The most permanent change is memories. Some people have stronger memories and they are more cue-reactive [more reactive to stimulus that triggers the reward pathway]. Nonaddicts won’t show that level of cue-reactivity.

For some people the addiction and withdrawal will be more intense through genetically mediated problems. Those people have a harder time stopping.


What else might account for Charlie Sheen’s strange behavior in those interviews?


One would want to explore the possibility of underlying psychiatric problems. The grandiosity, the loose associations, the jumbled flow suggest a thought disorder. Heavy, heavy drug use could cause that. Stimulant use can cause temporary thought disorder or intensify an underlying thought disorder or hypomanic state. To try to make a good diagnosis, whatever ongoing drug use there is would have to stop. After the withdrawal phase is resolved clinicians would then need to see if an underlying thought or mood disorder persisted. That would aid in parsing how much of a confusing clinical picture is due to drug use and how much is due to a primary mental disorder.


By Nina Bai , March 4, 2011

Medical screening tests are a great way to keep on top of your health. Think of them as basic maintenance, just like checking the oil and tire pressure to keep your car safe on the highway. To keep it simple, we’ve compiled a list of the most important medical tests every man should have—along with what age to start and how often to repeat. Here’s to routine maintenance for your health.


1. Cholesterol screening/lipoprotein profile
Cholesterol is a type of fatty protein in your blood that can build up in your arteries, so knowing how much cholesterol is present is a good predictor of your risk for heart disease. There are two kinds of cholesterol: HDL, or high-density lipoproteins, and LDL, or low-density lipoproteins. Confusingly enough, HDL is “good” and protects against heart disease, while LDL is “bad” and poses a risk to your heart.
Your total cholesterol reading combines the measures of both and is used as an overall reading; 220 is the magic number that you want to stay beneath. In addition, the profile measures triglycerides, which are fats in the blood that can also block arteries; you want them below 150 milligrams per deciliter.
What Are the New Cholesterol Tests?
What it is: A blood test for cholesterol, measured in milligrams per deciliter of blood (mg/dl); usually measures triglycerides at the same time
When to start: Age 20
How often: Every five years. If testing reveals your levels are high, your doctor will recommend retesting every six months to one year. If you have risk factors for heart disease in your family, the regular cholesterol test may not be specific enough; ask your doctor for an additional test called the lipoprotein subfraction test. It’s more sensitive and checks the size of the cholesterol particles as well as the amount.


2. Blood pressure check

It seems simple, but checking your blood pressure regularly is one of the most important things you can do to protect your present and future health. One in every five adults, totaling 50 million people, has elevated blood pressure, also known as hypertension. When your blood pressure readings are higher than the cutoff of 140/90, it puts stress on your heart, leaving you at risk for heart attack and stroke. Many experts believe 120/80 is a healthier target to shoot for.
What it is: A physical reading using an arm cuff
When to start: Any age; best to begin during childhood
How often: Once a year if readings are normal; your doctor will recommend every six months if readings are high or if you’re taking medication to control hypertension.


3. Diabetes screening
To check your risk for diabetes, doctors check your tolerance for glucose absorption, which means how readily your body digests sugar.
What it is: A blood draw performed after drinking a sugary drink; a fasting glucose tolerance test requires you not to eat for nine hours prior to the test.
When to start: At age 45 if you have no risk factors or symptoms. If you’re significantly overweight, have high blood pressure, or have other risk factors for diabetes, such as family history of the disease, it’s a good idea to get tested younger. If your insurance doesn’t cover it, free testing is available at most major chain drugstores.
How often: Every three years


4. Bone density test
The loss of bone strength, called osteoporosis, afflicts nearly 10 million people every year, according to the National Osteoporosis Foundation. Surveys show that men see osteoporosis as a “woman’s disease,” but this is a misconception. After age 50, 6 percent of all men will break a hip and 5 percent will have a vertebral fracture as a result of osteoporosis. As we age, minerals such as calcium begin to leach from bones, weakening them and leading to osteoporosis, which literally means “porous bone.”
What it is: A specialized X-ray called a DXA (dual-energy X-ray) screens your spine, hips, and wrists as you lie on a table.
When to start: At age 65, everyone should have a DXA. But men who have risk factors for bone loss, such as being thin, taking corticosteroids, or having a history of fractures, should talk to their doctor about being screened now.
How often: Every five years


5. Vitamin D test
Recently, doctors have realized that vitamin D is a key nutrient that helps maintain strong bones and protect against cancer, infection, and other health conditions. For example, a study last year found that men with low levels of vitamin D had a higher incidence of heart attack. Most men have no idea if they’re D-deficient or not, though a simple blood test can tell. If you live in a northern climate, work indoors, or don’t drink a lot of milk, chances are your vitamin D level is low. If so, your doctor will recommend taking a vitamin D supplement.
What it is: A blood test, often done along with the cholesterol and lipid panel, to check the level of vitamin D in your blood. You want your reading to be between 30 and 80 nanograms per milliliter, though some experts argue that 50 nanograms should be the lowest level considered normal. Many experts recommend the 25(OH)D3 test as providing the more accurate measurement.
When to start: Age 40; sooner if you have signs or risk factors for osteoporosis. As we age, our bodies become less efficient at synthesizing vitamin D from the sun, so after the age of 40 it’s more likely that you’ll become D-deficient. Also, if you have any signs of low bone density, such as a fracture, your doctor will want to test your vitamin D along with your bone density.
How often: Although vitamin D testing isn’t yet required or listed on the official schedule of recommended tests, more and more doctors are recommending it as an annual test after age 45.


6. Colonoscopy or
sigmoidoscop
y
Colorectal cancer, which is cancer of the lower part of the intestines, is curable in 90 percent of all cases—as long as it’s caught early. And screening tests that look inside the colon, called colonoscopy and flexible sigmoidoscopy, are the secret to catching it early.
Unfortunately, this still isn’t happening as often as it should. Currently, 39 percent of cases are already stage III or IV when discovered. This test is considered so lifesaving that news anchor Katie Couric allowed hers to be presented on live TV as an educational campaign to raise awareness after her husband died of colorectal cancer. Colorectal cancer is the third leading cause of death from cancer for men, after lung and prostate cancer, so it’s important to take it seriously.
What it is: An examination of your colon using a tiny scope and camera, which are inserted through the rectum. A colonoscopy can see the whole colon, while a sigmoidoscopy can see only the sigmoid, or lower section of the colon.
When to start: Age 50 for those with no risk factors. If, however, you have a first-degree family member who’s had colon cancer before the age of 50, begin colonoscopy screening when you’re 10 years younger than the age at which your family member was diagnosed. If a family member was diagnosed at 45, for example, you should have your first screening at 35.
How often: Flexible sigmoidoscopies should be repeated every five years, and a colonoscopy should be repeated every 10 years. A computerized imaging technique called virtual colonoscopy is gaining popularity at some medical centers, but many doctors still consider it experimental and some insurers, including Medicare, don’t cover it.


7. Fecal occult blood test (FOBT)
Although it sounds otherworldly, the word occult simply refers to the fact that this test checks for blood in the stool that’s not visible to the eye. This is the least invasive screening tool available. A chemical solution is used to test a stool sample for the presence of blood, which can indicate intestinal conditions such as Crohn’s disease and ulcerative colitis, or colorectal cancer.
Colorectal cancer still strikes more men than women—more than 50,000 men are diagnosed with the disease every year.
What it is: A stool sample test that looks for blood in the stool using a chemically treated pad that turns blue in the presence of blood. Three stool samples are collected on consecutive days, since cancer and other conditions may not bleed consistently.
When to start: At age 50; your doctor may suggest it earlier if there’s cause for concern about intestinal conditions.
How often: Yearly after age 50


8. Skin cancer screening
Skin cancer, while less deadly than some, is the No. 1 cancer diagnosed among Americans. And men are at higher risk for skin cancer than women, something most men don’t know. While most types of skin cancer are easily treated, one type, melanoma, can be deadly. Skin cancer is relatively easy to detect as long as you bring any suspicious areas to the attention of your doctor.
What it is: An examination of your skin, particularly moles, lesions, or other areas that are changing or growing.
When to start: Any age
How often: Experts recommend conducting a personal “mole check” once a month in the shower to look for unusual growths or changes to existing moles. If you notice anything suspicious, call your doctor. Many communities offer free skin cancer screenings, usually held at drug stores or clinics. They’re often held in May, just as the summer season begins and people start to expose more skin.


9. Eye exam and vision screening
Whether you have problems seeing at a distance or close up, you need regular eye exams as you age to check the overall health of your eyes. The American Academy of Ophthalmology says that by the year 2020, 43 million Americans will have some type of degenerative eye disease, yet surveys show that more than a third of adults fail to get regular eye exams.
What it is: A vision screening tests how well you can see; an eye exam checks for glaucoma, macular degeneration, retinopathy, and other eye diseases. Make sure you’re having both kinds of exams.
When to start: Age 18
How often: Every one to three years between the ages of 18 and 61, says the American Optometric Association; after that, as often as your doctor thinks is necessary depending on what’s happening with your vision. If you have diabetes, you’re at much higher risk for eye problems and should be checked more often.


10. Hearing test (audiogram)
Fourteen percent of adults between ages 45 and 64 have hearing loss, and by the age of 60 one in three adults is losing hearing. Men are at highest risk for all types of noise-induced hearing loss, the most common type. Yet many men go years before getting tested, primarily because hearing tests are voluntary. You and your doctor have to decide that you need a hearing test and request one.
If you notice problems following conversations, missed social cues, or an inability to distinguish people’s speech from background noise, ask for a referral to an otolaryngologist to check the condition of your ears, and an audiologist to check your hearing.
What it is: A series of tests to assess different aspects of hearing. Tone tests are used to measure your overall hearing, while additional tests check inner- and middle-ear function and evaluate your ability to register speech.
When to start: When you or others notice problems
How often: Hearing tests are voluntary, but the American Speech-Language-Hearing Association recommends hearing tests every 10 years for adults up to the age of 50. After that, experts say, you should have a hearing test every three years.


11. Thyroid test
The thyroid, a small gland in your neck, regulates your body’s metabolic rate. If your thyroid is overactive, a condition known as hypothyroidism, your metabolic rate is too high. Symptoms include insomnia, weight loss, and overactive pulse. If you’re hypothyroid, it means your thyroid is underactive and your metabolism will be slow and sluggish. This usually leads to fatigue, constipation, and weight gain. While more women than men are hypothyroid, that doesn’t mean men can’t be—and in men, hypothyroidism can cause some upsetting side effects, such as erectile dysfunction, low sex drive, and ejaculation problems.
What it is: The most common test, the TSH test, is a blood test that measures the level of thyroid-stimulating hormone. The desired level is between 0.4 and 5.5. However, many experts believe testing thyroxine (a hormone made by the thyroid) directly with what’s called the T4 test is a more accurate way to assess thyroid function.
When to start: Age 35
How often: Once a year, says the American Thyroid Association. Other doctors don’t recommend a thyroid test for midlife adults unless you have symptoms of hypothyroidism or hyperthyroidism. After the age of 60, thyroid testing is usually conducted annually.


12. Screening for metabolic syndrome
Metabolic syndrome is a group of symptoms that put you at increased risk for both diabetes and heart disease. The screening involves checking for a list of issues and, if they’re present, recommending additional tests. Doctors consider men to have metabolic syndrome if three of the following five risk factors are present:
Waist circumference greater than 40 inches
Low “good” cholesterol (below 40 mg/dL)
Elevated triglycerides (greater than 150 mg/dL)
Blood pressure higher thasting glucose above 100 mg/dL
If three or more of these apply, ask your doctor for an additional screening test called the C-reactive protein (CRP), which many experts think is the best way to monitor heart health risks.
What it is: A blood test that measures an inflammatory marker for plaque buildup
When to start: Age 50
How often: Every three to five years, along with cholesterol and diabetes screening


13. Testicular cancer screening

Lance Armstrong brought testicular cancer to national attention, but many men still don’t know the signs of this disease. With early detection, a man’s chances of survival go up by a whopping 90 percent, so it pays to be vigilant. While testicular cancer is rare, it’s the most common type of cancer in younger men, ages 15 to 34.
What it is: A self-exam or doctor’s exam for tumors in the testicle. The doctor (or you) rolls each testicle slowly between thumb and forefinger, looking for any hardened areas or lumps and checking to make sure there haven’t been changes in size.
When to start: All ages
How often: The Livestrong Foundation recommends that all men do a self-exam every month for testicular cancer. Sometimes a man’s partner is the first to notice signs of testicular cancer. At the first sign of concern, call your doctor and ask for an examination. Your doctor may also recommend an ultrasound or a blood test for tumor markers that can indicate testicular cancer.


14. Prostate cancer screening
Not the favorite of most men, the digital rectal exam is a lifesaver because prostate cancer is one of the most common types of cancer, affecting one in six men. A second test, called the PSA test, is used to look for elevated levels of prostate-specific antigen. While the PSA test has come under fire for producing a high number of false positives, it’s still the best first-line blood test for prostate cancer.
What it is: A digital rectal exam in which the doctor inserts a finger into the rectum to feel the prostate gland, and a blood test that measures the level of prostate-specific antigen.
When to start: Age 50, according to the American Cancer Society, unless you have symptoms such as difficulty with urination. In that case, see your doctor for a prostate cancer exam at age 45.
How often: Every year


15. Bladder cancer screening
Men, particularly Caucasian men and men who have a history of smoking, are at an elevated risk for bladder cancer. In the early stages, bladder cancer can be symptomless, and in these cases a test is the only way to detect it. There’s a good reason to be vigilant about bladder cancer: If caught while still localized, it has a cure rate of 95 percent. While routine bladder cancer screening is not yet recommended, talk to your doctor if you’re Caucasian and a smoker.
What it is: A urine test that looks for small amounts of blood in the urine not visible to the eye
When to start: Age 50, if you have a history of smoking
How often: When your doctor recommends it. Another test recently introduced checks the urine for a marker called NMP22; this test is expected to come into wider use in the next few years.


* By Melanie Haiken