Archive for June 9th, 2006
By: University of Queensland
i-Newswire, - The work is reported by Olivia Carter and Jack Pettigrew of the University of Queensland, Australia, and colleagues at the University of Queensland and the University of California, Berkeley.
Perceptual rivalry arises normally when two different images are presented to
each eye, and it is manifested as a fluctuation, typically, over the course of seconds, in the “dominant” image that is consciously perceived. The neural events underlying perceptual rivalry are not well understood but are thought to involve brain mechanisms that regulate attention and conscious awareness.
Some previous work had suggested that skilled meditation can alter certain aspects of the brain’s neural activity, though the significance of such changes in terms of actually understanding brain function remains unclear.
To gain insight into how visual perception is regulated within the brain, researchers in the new study chose to investigate the extent to which certain types of trained meditative practice can influence the conscious experience of visual perceptual rivalry.
With the support of His Holiness the Dalai Lama, 76 Tibetan Buddhist monks participated in the study, which was carried out at or near their mountain retreats in the Himalaya, Zanskar, and Ladakhi Ranges of India. The monks possessed meditative training ranging from 5 to 54 years; among the group were three “retreatist” meditators, each with at least 20 years of experience in isolated retreats.
The researchers tested the experience of visual rivalry by monks during the practice of two types of meditation: a “compassion”-oriented meditation, described as a contemplation of suffering within the world combined with an emanation of loving kindness, and “one-point” meditation, described as the maintained focus of attention on a single object or thought, a focus that leads to a stability and clarity of mind.
Whereas no observable change in the rate of “visual switching” during rivalry was seen in monks practicing compassion meditation, major increases in the durations of perceptual dominance were experienced by monks practicing one-point meditation. Within this group, three monks, including two of the retreatists, reported complete visual stability during the entire five-minute meditation period. Increases in duration of perceptual dominance were also seen in monks after a period of one-point meditation.
In a different test of perceptual rivalry, in this case prior to any meditation, the duration of stable perception experienced by monks averaged 4.1 seconds, compared to 2.6 seconds for meditation-naïve control subjects. Remarkably, when instructed to actively maintain the duration, one of the retreatist monks could maintain a constant visual perception during this test for 723 seconds.
The findings suggest that processes particularly associated with one-point meditation, perhaps involving intense attentional focus and the ability to stabilize the mind, contribute to the prolonged rivalry dominance experienced by the monks. The researchers conclude from their study that individuals trained in meditation can considerably alter the normal fluctuations in conscious state that are induced by perceptual rivalry and suggest that, in combination with previous work, the new findings support the idea that perceptual rivalry can be modulated by high-level, top-down neural influences.
The researchers include O.L. Carter, C. Callistemon, Y. Ungerer, G.B. Liu, and J.D. Pettigrew of University of Queensland; and D.E. Presti of University of California, Berkeley.
June 9th, 2006
By: JAMA
Patients who were first treated with an oral antibiotic and topical gel for acne were often able to maintain their clearer skin by using topical agents alone,
according to two studies in the May issue of the Archives of Dermatology, one of the JAMA/Archives journals.
Acne is a common, recurring disease, according to background information in the article. Acne treatment can be complex, often requiring aggressive combination therapy of oral antibiotics and medication applied directly to the skin (topical), as well as a long-term strategy. Because acne can return after successful treatment, maintenance therapy is necessary for many patients. However, due to reduced sensitivity of acne to some antibiotics, it has been recommended that antibiotic use be limited to three months. Topical retinoids, medications derived from vitamin A, have been identified as a choice for maintenance therapy.
Diane M. Thiboutot, M.D., of the Pennsylvania State University College of Medicine and Milton S. Hershey Medical Center, Hershey, and colleagues studied the efficacy of a gel containing adapalene, a retinoid-like compound, in maintaining the effects of successful acne treatment. Patients from a previous study were included if they had shown at least moderate improvement in their acne when treated with either adapalene gel and 100 mg of doxycycline (an oral antibiotic) or doxycycline and an unmedicated gel. A total of 253 patients aged 12 to 30 years were randomly assigned to receive either adapalene gel or unmedicated gel once daily for 16 weeks. Patients’ acne was evaluated at the beginning of the study and after four, eight, 12 and 16 weeks.
The group that continued treatment with adapalene gel had significantly higher rates of maintaining previous treatment success, defined as at least 50 percent improvement since beginning therapy, than the unmedicated gel group, 75 percent vs. 54 percent. During the study, the number of breakouts gradually increased in the unmedicated gel group, while remaining stable or decreasing in the adapalene gel group. In a survey, a significantly larger percentage of patients treated with adapalene gel were “very satisfied” or “satisfied” with the overall treatment, compared with patients treated with unmedicated gel (75 percent vs. 58 percent).
“The present 16-week and previous 12-week studies provide data to support regimens, such as those recommended in the recent acne treatment guidelines, wherein oral antibiotics can be used initially in combination with topical retinoids to gain control over the acne, and maintenance with adapalene can delay the recurrence of acne,” the authors write. (Arch Dermatol. 2006;142:597-602)
June 9th, 2006
By: CFSAN FDA
The inks used in tattoos and permanent makeup (also known as micropigmentation) and the pigments in these inks are subject to FDA regulation as cosmetics and color additives.
However, FDA has not attempted to regulate the use of tattoo inks and the pigments used in them and does not control the actual practice of tattooing.
Rather, such matters have been handled through local laws and by local jurisdictions.
But with the growth in popularity of tattooing and permanent makeup, FDA has begun taking a closer look at related safety questions. Among the issues under consideration are tattoo removal, adverse reactions to tattoo colors, and infections that result from tattooing.
Another concern is the increasing variety of pigments and diluents being used in tattooing — more than fifty different pigments and shades, and the list continues to grow. Although a number of color additives are approved for use in cosmetics, none is approved for injection into the skin. Using an unapproved color additive in a tattoo ink makes the ink adulterated. Many pigments used in tattoo inks are not approved for skin contact at all. Some are industrial grade colors that are suitable for printers’ ink or automobile paint.
Nevertheless, many individuals choose to undergo tattooing in its various forms. For some, it is an aesthetic choice or an initiation rite. Some choose permanent makeup as a time saver or because they have physical difficulty applying regular, temporary makeup. For others, tattooing is an adjunct to reconstructive surgery, particularly of the face or breast, to simulate natural pigmentation. People who have lost their eyebrows due to alopecia (a form of hair loss) may choose to have “eyebrows” tattooed on, while people with vitiligo (a lack of pigmentation in areas of the skin) may try tattooing to help camouflage the condition.
Whatever their reason, consumers should be aware of the risks involved in order to make an informed decision.
June 9th, 2006
By: FDA
Vaccine for Cervical Cancer and HPV
The Food and Drug Administration (FDA) today announced the approval of Gardasil, the first vaccine developed to prevent cervical cancer, precancerous genital lesions and genital warts due to human papillomavirus (HPV) types 6, 11, 16 and 18.
The vaccine is approved for use in females 9-26 years of age. Gardasil was
evaluated and approved in six months under FDA’s priority review process - a process for products with potential to provide significant health benefits
“Today is an important day for public health and for women’s health, and for our continued fight against serious life-threatening diseases like cervical cancer,” said Alex Azar, Deputy Secretary, U.S. Department of Health and Human Services (HHS). “HHS is committed to advancing critical health measures such as the development of new and promising vaccines to protect and advance the health of all Americans.”
HPV is the most common sexually-transmitted infection in the United States. The Centers for Disease Control and Prevention estimates that about 6.2 million Americans become infected with genital HPV each year and that over half of all sexually active men and women become infected at some time in their lives. On average, there are 9,710 new cases of cervical cancer and 3,700 deaths attributed to it in the United States each year. Worldwide, cervical cancer is the second most common cancer in women; and is estimated to cause over 470,000 new cases and 233,000 deaths each year.
For most women, the body’s own defense system will clear the virus and infected women do not develop related health problems. However, some HPV types can cause abnormal cells on the lining of the cervix that years later can turn into cancer. Other HPV types can cause genital warts. The vaccine is effective against HPV types 16 and 18, which cause approximately 70 percent of cervical cancers and against HPV types 6 and 11, which cause approximately 90 percent of genital warts.
“This vaccine is a significant advance in the protection of women’s health in that it strikes at the infections that are the root cause of many cervical cancers,” said Andrew C. von Eschenbach, MD, Acting Commissioner of Food and Drugs. “The development of this vaccine is a product of extraordinary work by scientists as well as by FDA’s review teams to help facilitate the development of very novel vaccines to address unmet medical needs. This work has resulted in the approval of a number of new products recently, including Gardasil, which address significant public health needs.”
Gardasil is a recombinant vaccine (contains no live virus) that is given as three injections over a six-month period. Immunization with Gardasil is expected to prevent most cases of cervical cancer due to HPV types included in the vaccine. However, females are not protected if they have been infected with that HPV type(s) prior to vaccination, indicating the importance of immunization before potential exposure to the virus. Also, Gardasil does not protect against less common HPV types not included in the vaccine, thus routine and regular pap screening remain critically important to detect precancerous changes in the cervix to allow treatment before cervical cancer develops.
“This is the first vaccine licensed specifically to prevent cervical cancer. Its rapid approval underscores FDA’s commitment to help make safe and effective vaccines available as quickly as possible. Not only have vaccines dramatically reduced the toll of diseases in infants and children, like polio and measles, but they are playing an increasing role protecting and improving the lives of adolescents and adults,” said Jesse Goodman, MD, MPH, Director of FDA’s Center for Biologics Evaluation and Research.
Four studies, one in the United States and three multinational, were conducted in 21,000 women to show how well Gardasil worked in women between the ages of 16 and 26 by giving them either the vaccine or placebo. The results showed that in women who had not already been infected, Gardasil was nearly 100 percent effective in preventing precancerous cervical lesions, precancerous vaginal and vulvar lesions, and genital warts caused by infection with the HPV types against which the vaccine is directed. While the study period was not long enough for cervical cancer to develop, the prevention of these cervical precancerous lesions is believed highly likely to result in the prevention of those cancers.
The studies also evaluated whether the vaccine can protect women already infected with some HPV types included in the vaccine from developing diseases related to those viruses. The results show that the vaccine is only effective when given prior to infection.
Two studies were also performed to measure the immune response to the vaccine among younger females aged 9-15 years. Their immune response was as good as that found in 16-26 year olds, indicating that the vaccine should have similar effectiveness when used in the 9-15 year age group.
The safety of the vaccine was evaluated in approximately 11,000 individuals. Most adverse experiences in study participants who received Gardasil included mild or moderate local reactions, such as pain or tenderness at the site of injection.
The manufacturer has agreed to conduct several studies following licensure, including additional studies to further evaluate general safety and long-term effectiveness. The manufacturer will also monitor the pregnancy outcomes of women who receive Gardasil while unknowingly pregnant. Also, the manufacturer has an ongoing study to evaluate the safety and effectiveness of Gardasil in males.
Gardasil is manufactured by Merck & Co., Inc., of Whitehouse Station, NJ.
June 9th, 2006
(CBS) Today’s New England Journal of Medicine has a study that links caffeine to the risk of miscarriage in pregnant women. Dr. Bernadine Healy tells us more about the findings.
For years, obstetricians and prenatal healthcare providers have suspected a connection
between caffeine and miscarriage, so they advised pregnant women to limit their caffeine intake. A new study in the New England Journal of Medicine reveals that five cups of coffee per day more than DOUBLES a pregnant woman’s chance of having a miscarriage.
In the meantime, the US Food and Drug Administration and the March of Dimes, which funds research on birth defects, have both advised pregnant women to curtail caffeine. Caffeine, which is easily passed to the fetus, stays in the body longer among pregnant women.
Unlike earlier research, the latest study looked at women in the first trimester, when most miscarriages occur. It also tried to account for a separate risk from genetic defects in fetuses and a possible risk from smoking.
The More You Drink, The Greater The Risk
The research team in Sweden and the United States found that the equivalent of one-to-three cups of American coffee increases the risk of miscarriage by 30%. Three to five cups raises the risk by 40%. Five cups or more yields more than doubled the risk.
Not All Coffee Are Created Equal
The findings are based on interviews with 562 women who had miscarriages between six to 12 weeks of pregnancy (the first trimester), and 953 pregnant women who did not. Since they were Swedish, they often drank stronger coffee than Americans did. The results are “translated” to American cups of coffee.
A cup of Swedish coffee typically carries about 180 milligrams (”mg”) of caffeine, compared to the 100 mg in a typical American cup of coffee.
Smokers May Not Have Increased Risk
Interestingly, among nonsmokers, more miscarriages occurred in women who drank at least 100mg per day. Among smokers, caffeine was NOT associated with increased risk of abortion. The researchers say this is probably because the smokers already face a higher risk of miscarriage.
Two Cups Still Okay
Dr. Sven Cnattingius of the Karolinska Institute in Stockholm directed the study. He suggests that pregnant women curtail their coffee to the equivalent of about two American cups per day.
Caffiene In Drinks & Medicine
Tea, cocoa and coke normally contain less caffeine per ounce than coffee. But the study suggests a similar effect on miscarriage for these drinks and for medications with caffeine, if enough is consumed. Caffeine is also present in chocolate.
On The Other Hand: The Morning Sickness Effect
The researchers also tried to account for the effects of morning sickness, which tended to exaggerate the impact of caffeine in earlier studies because nausea is more common in pregnant women with healty fetuses. Since morning sickness gives many women with healthy fetuses a distaste of coffee, more unhealthy fetuses are found among coffee drinkers.
Dr. Mark Klebanoff, at the National Institute of Child Health and Human Development, who was familiar with the findings, said it is still possible that morning sickness skews the results. “I think it will never be completely possible to rule it out, no matter how good a study you do,” he said. But Klebanoff said this study is probably the strongest yet, because it was specifically designed to answer whether caffeine promotes miscarriage. Other studies used data initially collected to resolve other questions.
June 9th, 2006