2/15/2009
Is too much exercise a bad thing?
Doctors at the University of Maryland Medical Center had a mystery on their hands. A 51-year-old physician colleague who looked the picture of healthno cardiovascular risks, a marathon runner who had exercised vigorously each day for 30 yearshad just flunked a calcium screening scan of his heart.The...
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Doctors at the University of Maryland Medical Center had a mystery on their hands. A 51-year-old physician colleague who looked the picture of health%26#8212;no cardiovascular risks, a marathon runner who had exercised vigorously each day for 30 years%26#8212;had just flunked a calcium screening scan of his heart.
The patient had expected a score indicating a healthy cardiovascular system. Instead, the images indicated a high score: a build-up of calcium in his coronary arteries put him at high risk for blocked blood vessels and a possible heart attack.
The mystery was all the more intriguing because his resting blood pressure and fasting cholesterol levels, the usual measures of cardiovascular health, were in the normal range.
In the March 1, 2007, issue of the American Journal of Cardiology, the researchers say this is the first case, to their knowledge, of advanced coronary calcification in an otherwise healthy middle-aged male marathon runner who lacked traditional cardiac risk factors and had no symptoms of heart disease.
The researchers conclude that the physician%26#8217;s intense, long-term exercise regime, coupled with a predisposition toward a type of hypertension, contributed to his cardiovascular disease. "In this particular individual, we think that oxidative stress was an important contributor," says the study%26#8217;s senior author, Michael Miller, M.D., director of preventive cardiology at the University of Maryland Medical Center and associate professor of medicine at the University of Maryland School of Medicine. "But we also found that this individual has exercise-induced hypertension, which I think is vastly under-diagnosed."
Oxidative stress is a byproduct of the normal cellular metabolism of oxygen. It refers to cell, tissue or organ damage from a class of molecules associated with oxygen metabolism, including unstable molecules called "free radicals." Oxidative stress plays a role in many heart, lung, blood and sleep disorders, including atherosclerosis, or hardening of the arteries, hypertension, heart failure, asthma and sleep apnea.
To help gage the impact of oxidative stress on the patient%26#8217;s cardiovascular system, his doctors evaluated the response to exercise of the endothelium, the lining of his arteries. An ultrasound device was used to measure what is known as flow-mediated vasodilation. It shows how well the endothelium responds to a sudden increase in the flow of blood through an artery in the upper arm. The endothelium in a healthy vessel typically dilates or expands during this test to accommodate the increased blood flow, while an impaired vessel constricts or narrows.
The patient's blood vessel dilation was normal before exercising. But after exercise, vessel constriction occurred immediately and showed no improvement after an hour. To put this response into perspective, the researchers administered the same exercise/blood vessel response test to a group of ten men whose mean age was 41. The vessels of these men initially constricted, but improved significantly one hour after exercise.
Several weeks later, the patient was given vitamins C and E just before exercise and was tested again for endothelial response. These vitamins are known as antioxidants and may protect cells from free radical damage. This time, the test revealed a partial reversal of the blood vessel constriction after one hour, and normalization after two hours.
"As he took the vitamin C and vitamin E, you could see improvements in his brachial arteries," says Dr. Miller. "We recommended that the patient take these vitamins before he runs."
With half the mystery solved, the research team explored another possible cause of the calcium buildup%26#8212;elevated blood pressure. Hypertension can cause artery walls to thicken and the endothelium to narrow. This narrowing can promote the formation of fatty plaque deposits in artery walls. The plaque, from cholesterol and fats, can eventually harden or calcify.
Although hypertension did not seem to be a risk factor for this patient, exercise is a major factor in his life. So, the researchers turned to a treadmill stress test to measure his blood pressure during exercise. At the start of the treadmill test, his baseline blood pressure was normal, 118/78 millimeters of mercury (mmHg). He was in such great shape that it took 20 minutes to reach high blood pressure levels, and this happened only after the treadmill speed and incline had been raised. But by the end of the test, his blood pressure had soared to 230/78 mmHg. A check of several of his previous treadmill tests indicated a similar rise in blood pressure.
On the basis of running duration and intensity, the researchers estimated that the patient spent about 30 minutes a day at a systolic blood pressure above 200 mmHg. This number is well into the blood pressure danger zone and meets one definition of exercise-induced hypertension%26#8212;a jump of at least 60 mmHg from baseline after exercise.
This finding should be investigated further, says co-investigator Matthew R. Weir, M.D., head of nephrology at the University of Maryland Medical Center and professor of medicine and head of the division of nephrology at the University of Maryland School of Medicine. %26#8220;Because we know that blood pressure rises during a stress test, we tend not to pay attention to it. We%26#8217;re more interested in changes in electrical activity and the redistribution of blood during exercise, which could indicate inadequate blood supply to the heart muscle,%26#8221; says Dr. Weir. %26#8220;The question is, should we pay more attention to treadmill-induced changes in blood pressure as a means to identify people at risk for developing coronary artery disease?%26#8221;
Dr. Miller adds another question, "Should we screen all middle-aged individuals who want to participate in an exercise program to make sure they don%26#8217;t have exercise-induced high blood pressure?"
Unlike cholesterol or triglyceride levels, blood pressure levels fluctuate dramatically throughout the day, depending on a variety of factors such as exercise, emotions and even the time of day. In light of that phenomenon, Dr. Weir says the study raises another issue. "This research indicates that we need a more dynamic measure of blood pressure to truly profile the risk of an individual. We%26#8217;ve been using casual, at-rest office readings of blood pressure for more than 50 years. It%26#8217;s not bad, but it%26#8217;s not the answer." The treadmill is one way to gather a more dynamic measurement, but he says there%26#8217;s an easier option. "It can even be done at home if you have a blood pressure cuff and someone who can take your blood pressure at peak exercise."
The patient in the study continues to run, but is now taking medications to lower both his cholesterol and blood pressure. Despite his exercise regime, he appears to be in the same boat as millions of Americans who do not exercise regularly. So, is too much exercise a bad thing? The physicians answer to the contrary. "We are not publishing this report to suggest in any way that people should not be exercising. Exercise has stood the test of time as being one of the best ways to modify cardiovascular risk," says Dr. Miller. %26#8220;But what we%26#8217;re looking at are improved detection methods for predicting those at risk. Exercise-induced high blood pressure may be a part of that.%26#8221;
Source:
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Drug delivery system consists of nanocrystals of a hydrophobic drug
The problem of efficiently delivering drugs, especially those that are hydrophobic or water-repellant, to tumors or other disease sites has long challenged scientists to develop innovative delivery systems that keep these drugs intact until reaching their targets.Now scientists in the University at ...
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The problem of efficiently delivering drugs, especially those that are hydrophobic or water-repellant, to tumors or other disease sites has long challenged scientists to develop innovative delivery systems that keep these drugs intact until reaching their targets.
Now scientists in the University at Buffalo's Institute for Lasers, Photonics and Biophotonics and Roswell Park Cancer Institute have developed an innovative solution in which the delivery system is the drug itself.
They describe for the first time in Molecular Pharmaceutics a drug delivery system that consists of nanocrystals of a hydrophobic drug.
The system involves the use of nanocrystals measuring about 100 nanometers of pure HPPH, (2-devinyl-2-(1'-hexyloxyethyl) pyropheophorbide), a photosensitizer currently in Phase I/II human clinical trials at RPCI for treating various types of cancer.
The UB researchers found that the nanocrystals of HPPH were taken up by tumors in vivo, with efficacy comparable to conventional, surfactant-based delivery systems.
A patent has been filed on this work.
"In this case, the drug itself acts as its own carrier," said Haridas Pudavar, Ph.D., UB research assistant professor of chemistry and a co-author.
The nanocrystals present a major advantage over methods of delivery involving other carriers, according to Paras Prasad, Ph.D., SUNY Distinguished Professor in the Department of Chemistry in UB's College of Arts and Sciences, executive director of the institute and a co-author.
Because other delivery systems, especially those containing surfactants, commonly used with HPPH and many other drugs, may add to the toxicity in the body, they have been considered imperfect solutions.
"Unlike formulations that require separate delivery systems, once this drug is approved, no additional approvals will be needed," said Prasad.
"Our published data in animal models demonstrate no difference in drug activity with the nanocrystal formulation," said Ravindra Pandey, Ph.D., Distinguished Professor of Biophysical Sciences at RPCI and a co-author on the paper.
"This is a case where the easiest formulation works the best," added Indrajit Roy, Ph.D., UB research assistant professor of chemistry and another co-author.
The researchers found that because HPPH is amphiphillic, i.e., partially soluble in water and oil, nanocrystals of it will self-assemble, that is, in solution the molecules aggregate, but not into such big clusters that they settle to the bottom.
"It's a controlled formation of a colloidally stable suspension of nanosized crystals," explained Tymish Ohulchanskyy, Ph.D., UB senior research scientist and a co-author.
The researchers originally were investigating nanocrystals as a delivery method for hydrophobic dyes in bioimaging applications, another promising use for nanocrystals that they continue to pursue.
Further in vivo studies with HPPH nanocrystals are being conducted by scientists at UB and RPCI, including Pandey and Allan R. Oseroff, M.D., Ph.D., chair of the department of dermatology at RPCI and in UB's School of Medicine and Biomedical Sciences.
The UB/RPCI team is exploring the use of the same technique for delivering other hydrophobic drugs, including those used in chemotherapy.
Source: University at Buffalo
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Scientists build new model of enzyme responsible for all aerobic life on Earth - May help researchers gain insights into causes of cancer and other major diseases
The protein cytochrome c oxidase (CcO) is the ultimate enzyme responsible for all aerobic life on Earth, from bacteria to people. It is also a crucial component of the cellular machinery that generates energy in our body. With such impressive credentials, you might expect that scientists would have ...
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The protein cytochrome c oxidase (CcO) is the ultimate enzyme responsible for all aerobic life on Earth, from bacteria to people. It is also a crucial component of the cellular machinery that generates energy in our body. With such impressive credentials, you might expect that scientists would have a clear understanding of how CcO works. But they don't, according to James P. Collman, professor emeritus of chemistry at Stanford University.
To help scientists achieve a better understanding of how CcO works, Collman and his colleagues have built a new model of the enzyme's active site-a region on the protein's surface where chemical reactions occur. According to Collman, this new model might eventually help researchers gain insights into the causes of cancer and other major diseases, and might even prove useful in the development of new forms of alternative energy. The team's findings appear in the March 16 issue of the journal Science.
Energy source
Many organisms, including humans, derive their energy from tiny organelles in cells known as mitochondria. Embedded in the membrane of each mitochondrion is a structure called the electron transport chain, which produces adenosine triphosphate (ATP), a molecule that is the source of the cell's energy. The transport chain is made up of a series of proteins known as electron carriers. Each carrier receives electrons from the preceding one, then transfers them down the chain. The final receptor of the electrons is a molecule of oxygen that is transformed into water and, in the process, generates energy in the form of ATP and heat.
CcO is the last electron carrier in the transport chain. It receives four electrons from the other carriers and transfers the electrons to the molecule of oxygen, converting it into two molecules of water.
"CcO has to behave perfectly," Collman said. "If it adds less than four electrons, it can produce partially reduced oxygen molecules, and these are known to be very toxic." The two most deleterious forms of reduced oxygen are superoxide and hydrogen peroxide, which have been implicated in cancer, heart failure, Alzheimer's disease and other illnesses, he added.
The good news is that CcO rarely fails, said Stanford postdoctoral fellow Neal K. Devaraj, whose doctoral dissertation was the basis of the Science paper. According to Devaraj, CcO has more than 99 percent efficiency in transforming oxygen into water.
To understand why CcO is so efficient, Collman's group, led by Stanford research associate Richard Decreau, created an artificial version of the enzyme active site using organic compounds as building materials. The imitation site, which involves an elaborate sequence of 32 chemical steps, was built from scratch and took several years to develop.
The site contains the three active centers found in the naturally occurring enzyme: an organic molecule called phenol, an iron atom and a copper atom. Working together, these three centers provide the four electrons necessary to transform oxygen into water. "How all four electrons are added to oxygen has always been mysterious," Collman said. "Very few people study it. It's quite complex, and it's been broadly ignored."
Each electron is brought to the enzyme one at a time, Collman said: "It's like a bucket brigade in a Western movie." But the electrons are consumed too fast to study individually, he noted. Therefore, the researchers had to invent a technique that supplied electrons to their enzyme model in a slow and continuous way. They solved the problem by attaching the model to a liquid crystalline film on a gold electrode, which provided a nonstop supply of electrons to the model as it transformed oxygen molecules into water-a process called steady turnover.
"The biochemists that study the enzyme typically study single turnover," Collman said. "They let the enzyme have only one oxygen molecule and watch what happens." He said that single turnover is like taking a single photograph of an event, while steady turnover is like shooting a movie.
Damaged enzymes
Once Collman's group had solved the continuous electron supply problem, the scientists systematically removed each of the three active centers-phenol, iron and copper-one at a time, as if the enzyme had been damaged and a specific active center was missing. "We found that great damage occurred, and that partially reduced oxygen species were produced in large amounts," Collman said. This finding led the researchers to conclude that all three active sites are essential for the proper functioning of the enzyme.
According to Devaraj, the new laboratory techniques developed in this experiment may have applications for research involving other enzymes. Understanding what makes CcO so efficient in reducing oxygen to water may even be useful to the study of fuel cells-very efficient power sources that convert chemical energy to electricity. "If we can develop better catalysts to do that reduction, we can get better fuel cells," Devaraj explained.
Source: Stanford University
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Soy foods decreased risk of localized prostate cancer but increased risk of advanced prostate cancer
The largest study examining the relationship between the traditional soy-rich Japanese diet and development of prostate cancer in Japanese men has come to a seemingly contradictory conclusion: intake of isoflavone chemicals, derived largely from soy foods, decreased the risk of localized prostate ca...
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The largest study examining the relationship between the traditional soy-rich Japanese diet and development of prostate cancer in Japanese men has come to a seemingly contradictory conclusion: intake of isoflavone chemicals, derived largely from soy foods, decreased the risk of localized prostate cancer but increased the risk of advanced prostate cancer.
The prospective study of 43,509 men, published in the March issue of Cancer Epidemiology, Biomarkers %26amp; Prevention, suggests that the effects of isoflavones on prostate cancer development may differ according to disease stage, say researchers at the National Cancer Center in Japan.
One possible explanation is that isoflavones may delay the progression of latent prostate cancer only; once tumors lose estrogen-receptor beta expression and become aggressive, isoflavones may fail to protect against the development of advanced cancer, and might even increase the risk of progression, possibly by reducing serum testosterone, researchers say. It is also possible that advanced and localized prostate cancer may be different tumor subtypes, which may react differently to isoflavones.
"The present findings provide no clear understanding of when or how localized cancer will develop to aggressive cancer, and of the related effect of isoflavones," said the study's first author, Norie Kurahashi, M.D., of the Epidemiology and Prevention Division of the National Cancer Center.
"Given that Japanese consume isoflavones regularly throughout life, we do not know the period during which the effects of isoflavones on prostate cancer are preventive, and further research is required to find that out, including well-designed clinical trials," she said.
Until those studies are done, the researchers recommend that Japanese men continue to consume isoflavones through their food and not through supplements.
"Consumption of isoflavones from traditional Japanese food throughout life may protect against the incidence of prostate cancer, but we cannot recommend the use of isoflavones from supplements for people who do not regularly consume these chemicals, because the relationship between isoflavones and the risk of advanced prostate cancer is not yet clear," Kurahashi said.
Isoflavones act as both strong antioxidants and plant-based estrogens. Soybeans are the most common source of isoflavones, especially genistein and daidzein, which have been shown in some animal studies to exert a protective effect against prostate cancer.
Japanese men eat significantly more soy-based foods than do Western men, and the incidence of prostate cancer is much lower in Asian countries than in Western countries. Still, reviews of latent, or clinically insignificant, prostate cancer findings in autopsy reports have revealed no difference between the populations so scientists have theorized that isoflavones stop latent cancers from developing further.
But because smaller epidemiological studies in Japan have reached differing conclusions about the protective effects of soy on prostate cancer development, this research team conducted the most comprehensive analysis to date. They polled thousands of men age 40-69 about their consumption of 147 foods, the most popular of which were miso soup (primarily made from fermented soybeans), natto (also a product of fermented soybeans) and tofu, made from soy milk. Japanese consume miso soup more frequently, usually daily, than other soy foods, and miso, natto, and tofu account for about 90 percent of the population's consumption of daidzein and genistein, according to Kurahashi.
The researchers then followed participants from 1995 through 2004 and found that 307 men were diagnosed with prostate cancer. In this group, 74 cases were advanced, 218 were confined to the prostate organ, and 15 were of undetermined stage.
They concluded that intake of genistein, daidzein, miso soup and soy food had no overall link to diagnosis of prostate cancer. However, they calculated that the risk of developing localized prostate cancer was 50 percent lower in men who ate the most isoflavones compared to men who ate the least %26#8722; meaning that men in the top category ate between two and three times as much isoflavone-rich food.
However, in a discovery they cannot explain, they also calculated that the risk of developing advanced prostate cancer was twice as high in men who consumed two or more bowls of miso soup a day than in men who ate less than one bowl of soup.
They also found that the protective effect of isoflavone-rich food was strongest in men who were older than 60: the more isoflavones they ate, the more they reduced their risk of developing localized prostate cancer. "Isoflavone may be protective for localized prostate cancer only in men aged more than 60 years, and may not have a protective effect in the early stage of prostate cancer in younger men," the researchers conclude in their study.
The inconsistencies in the finding %26#8722; that isoflavones decreased the risk of localized prostate cancer, but not the risk of advanced prostate cancer %26#8722; could be errors in food measurement, or
could be due to the fact that the number of participants who developed advanced prostate cancer was small, said Kurahashi. Or, as researchers speculate, isoflavones could interact with the estrogen receptor on prostate tissue enough to inhibit production of testosterone, which can fuel prostate cancer. When tumors lose all of their estrogen receptors and stop responding to isoflavone-induced hormonal interference, they grow aggressively.
"A broad body of research is required to clarify the timing and period of isoflavones' preventive effect on prostate cancer development," Kurahashi said.
Source: American Association for Cancer Research
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Success of long term hip replacement surgery may lie in your genes
The success of long term hip replacement surgery may lie in the genes, suggests research published ahead of print in the Annals of the Rheumatic Diseases.The researchers analysed genetic variations in 312 people, just over half of whom (162) had problems after hip replacement in the 10 years followi...
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The success of long term hip replacement surgery may lie in the genes, suggests research published ahead of print in the Annals of the Rheumatic Diseases.
The researchers analysed genetic variations in 312 people, just over half of whom (162) had problems after hip replacement in the 10 years following surgery.
Among those with symptoms, 91 had early signs of %26#8220;aseptic loosening,%26#8221; which describes a condition in which the artificial joint comes loose and the surrounding bone begins to dissolve. The other 71 patients had deep-seated infection, which occurs when the body is unable to control infection caused by bacteria colonising the artificial implants.
DNA samples were taken from all participants to test for genetic variations in genes responsible for generating matrix metalloproteinase 1, or MMP1 for short, interleukin 6, and vitamin D synthesis.
MMP1 is an enzyme that breaks down collagen, the main protein found in bone and cartilage, while interleukin 6 is a chemical involved in bone metabolism and the immune response.
Vitamin D synthesis is important for strong healthy bones.
Variations in the interleukin 6 gene did not seem to have any effect. But those with variations in MMP1 were more than three times as likely to have aseptic loosening as those who did not carry the genetic variation.
And variations in the vitamin D receptor gene almost doubled the chances of bone dissolution and deep infection.
The authors conclude that if confirmed in other research, these findings could be used to predict long term success in patients undergoing hip replacement surgery. And they could also be used to develop targeted genetic treatments.
Source: British Medical Journal
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Embryonic stem cells implanted in brain appear to develop into fully differentiated granule neurons
In order to differentiate and specialize, stem cells require very specific environmental cues in a very specific order, and scientists have so far been unable to prod them to go through each of the necessary steps. But now, for the first time, a study in mice by Rockefeller University scientists sho...
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Image: When differentiated embryonic stem cells were implanted into the cerebellums of newborn mice (green), they migrated to the internal granule layer -- the area where fully differentiated granule neurons extend dendrites (bottom right).
Embryonic stem cells have shown a great deal of promise for alleviating heart disease and regenerating organs. But for some of the conditions for which people hold out the most hope -- Alzheimer's and Parkinson's, for example -- there's been little evidence to date that stem cells can work. Part of the problem is that neural stem cells, especially those involved in brain development, specialize as they mature and lose their ability to diversify. They require very specific environmental cues in a very specific order, and scientists have so far been unable to prod them to go through each of the necessary steps. But now, for the first time, a new study in mice shows that embryonic stem cells implanted in the brain appear to develop into fully differentiated granule neurons, the most plentiful neurons in the cerebellum.
The cerebellum, which is tucked into the lower, rear portion of the mammalian brain, contains neural circuits that are responsible for motor learning, motor memory and sensory perception. It's also the location of 40 percent of pediatric brain tumors. Mary E. Hatten, Rockefeller's Frederick P. Rose Professor and head of the Laboratory of Developmental Neurobiology, has been studying granule cells for 30 years; she sees her results as a step toward understanding how embryonic stem cells could be regulated in vivo and ultimately used for cell replacement therapy, especially after childhood tumors, in the central nervous system.
Hatten and postdoc Enrique Salero found that in order to get the embryonic stem cells to differentiate, progressing through each of the known steps of granule neuron maturation as they did so, the cells had to be treated with signals that induce specific transcription factors - proteins that can turn genes on and off - in a specific order. The researchers then implanted the newly differentiated cells into a specific spot in the brains of newborn mice, the gray layer on the surface of the cerebellum called the cerebellar cortex. Once in the brain, the cells extended parallel fibers, migrated to and incorporated themselves into the internal granule cell layer, and extended short projections called dendrites, something that neurons use to communicate with each other. Each of these steps, Hatten says, is characteristic of a typical granule cell.
Salero and Hatten then looked for evidence that their embryonic stem cells had not just gone through the developmental steps of young granule neurons, but that they also had the known markers of young granule neurons, including those indicating that the neurons had formed in the cerebellum. "We're excited about this paper because it's the first time that anybody has shown that a cell not only migrates to where it's supposed to go, but extends dendrites," Hatten says. "So they're actually in the synaptic network that's sitting on the cortex."
Hatten isn't yet convinced that the cells differentiated into true granule neurons. "There is such wild-eyed enthusiasm over stem cells," she says, "but it's very hard to know when you've provided sufficient evidence that a cell is actually what you say it is." So her next step will be to work with Nathaniel Heintz, an HHMI investigator and Rockefeller's James and Marilyn Simons Professor, to determine how close a genetic match the native granule cells are to the embryonic stem cell-derived versions.
"This whole field of stem cell biology is exciting, but also frightening because of the potential harm that could be done," Hatten says. "We have made a lot of progress with stem cells outside the brain, especially with the heart and skin. But neurons in the brain seem to undergo more complicated genetic changes as they progress through a long series of maturation steps. So we want to be absolutely sure that we're generating neurons that will aid, rather than hamper, brain function."
Source: Rockefeller University
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Intercessory prayer has positive effect among people with psychological or medical problems
Does God or some other type of transcendent entity answer prayer?The answer, according to a new Arizona State University study published in the March journal Research on Social Work Practice, is yes. David R. Hodge, an assistant professor of social work in the College of Human Services at Arizona St...
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Does God or some other type of transcendent entity answer prayer?
The answer, according to a new Arizona State University study published in the March journal Research on Social Work Practice, is %26#8220;yes.%26#8221; David R. Hodge, an assistant professor of social work in the College of Human Services at Arizona State University, conducted a comprehensive analysis of 17 major studies on the effects of intercessory prayer %26#8211; or prayer that is offered for the benefit of another person %26#8211; among people with psychological or medical problems. He found a positive effect.
%26#8220;There have been a number of studies on intercessory prayer, or prayer offered for the benefit of another person,%26#8221; said Hodge, a leading expert on spirituality and religion. %26#8220;Some have found positive results for prayer. Others have found no effect. Conducting a meta-analysis takes into account the entire body of empirical research on intercessory prayer. Using this procedure, we find that prayer offered on behalf of another yields positive results.%26#8221;
Hodge%26#8217;s work is featured in the March, 2007, issue of Research on Social Work Practice, a disciplinary journal devoted to the publication of empirical research on practice outcomes. It is widely recognized as one of the most prestigious journals in the field of social work.
Hodge noted that his study is important because it is a compilation of available studies and is not a single work with a single conclusion. His %26#8220;Systematic Review%26#8221; takes into account the findings of 17 studies that used intercessory prayer as a treatment in practice settings.
%26#8220;Some people feel Benson and associates%26#8217; study from last year, which is the most recent and showed no positive effects for intercessory prayer, is the final word,%26#8221; said Hodge, referring to a 2006 article by Dr. Herbert Benson of the Harvard Medical School that measured the therapeutic effect of intercessory prayer in cardiac bypass patients. %26#8220;But, this research suggests otherwise. This study enables us to look at the big picture. When the effects of prayer are averaged across all 17 studies, controlling for differences in sample sizes, a net positive effect for the prayer group is produced.
%26#8220;This is the most thorough and all-inclusive study of its kind on this controversial subject that I am aware of,%26#8221; said Hodge. %26#8220;It suggests that more research on the topic may be warranted, and that praying for people with psychological or medical problems may help them recover.%26#8221;
The use of prayer as a therapeutic intervention is controversial. Yet, Hodge notes that survey research indicates that many people use intercessory prayer as an intervention to aid healing, which raises questions about its effectiveness as an intervention strategy.
%26#8220;Overall, the meta-analysis indicates that prayer is effective. Is it effective enough to meet the standards of the American Psychological Association%26#8217;s Division 12 for empirically validated interventions? No. Thus, we should not be treating clients suffering with depression, for example, only with prayer. To treat depression, standard treatments, such as cognitive therapy, should be used as the primary method of treatment.%26#8221;
In addition to his inclusion in the upcoming issue of Research on Social Work Practice, Hodge is widely published and has appeared on the pages of Social Work, Social Work Research, Journal of Social Service Research, Journal of Marital and Family Therapy, and Families in Society. He has also authored the book %26#8220;Spiritual assessment: A handbook for helping professionals.%26#8221;
Source: Arizona State University
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Scientists able to shut down gene that plays a crucial role in a leading cause of inherited blindness
University of Florida researchers have used an experimental therapy in mice to shut down a gene that plays a crucial role in a leading cause of inherited blindness.The technique, detailed in an upcoming issue of Vision Research, involves injecting the eye with a bit of genetic material called interf...
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University of Florida researchers have used an experimental therapy in mice to shut down a gene that plays a crucial role in a leading cause of inherited blindness.
The technique, detailed in an upcoming issue of Vision Research, involves injecting the eye with a bit of genetic material called interfering RNA, which helps disable the gene.
Normally the gene is essential for healthy eyesight, but mutated versions of it are passed from generation to generation in some families and can lead to blindness.
Disabling the gene is a step toward developing a gene therapy to treat people with retinitis pigmentosa, an inherited disease that attacks the light-sensing cells in the eye. It affects about one in 60,000 people, with an estimated 1.5 million people afflicted worldwide.
"One of the causes of the disease is mutated gene expression," said Marina Gorbatyuk, Ph.D., an assistant professor of molecular genetics and microbiology in the UF College of Medicine. "We work with rhodopsin, which is the main retinal protein. Without it, or if it is mutated, people simply won%26#8217;t see."
Mutated forms of the rhodopsin produce a toxic protein in the retina that kills cells that receive light. People with the disease usually notice symptoms between the ages of 10 and 30. At first they have problems seeing in dimly lit places, followed by loss of their peripheral sight. The rate of progression varies, but most patients are blind by 40.
UF Genetics Institute researchers engineered the interfering RNA into a virus, which in turn was injected below the retinas in more than a dozen normal mice. Analysis showed the technique reduced the amount of rhodopsin by about 60 percent.
With the gene drastically muzzled, scientists have begun experiments to create a therapy in which healthy versions of the gene can be introduced into the eye using an apparently harmless virus to deliver the genetic material.
"If we reduce the amount of protein formed by mutated rhodopsin, that may be sufficient to maintain vision in people who are affected by retinitis pigmentosa," Gorbatyuk said. "The second step, introducing the normal gene to the retina, will show whether we are able to restore vision in this model or not."
If both steps are perfected, scientists plan to study the treatment in a larger animal model and then possibly move to a human clinical trial.
Source: University of Florida
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