NEW VACCINES
Cuba has new vaccine for cholera, the US develops one for shingles, while China is testing another for SARS
War not always bad for soldiers' psychological health
LONDON
While it has long been associated with distressing psychological condition such as shell shock, war can sometimes be good for a soldier's mental health, according to a British study.
Researchers from King's College London, who looked at the psychological well-being of hundreds of British troops before and after they served in Iraq, found a significant relative improvement in their overall mental state.
The survey published in the British Journal of Psychiatry analyzed questionnaires from 421 members of 16 Air Assault Brigade, before and after taking part in operations in Iraq for around four months.
The team led by Dr. Jamie Hacker Hughes analyzed the soldiers' psychological scores and concluded that they revealed "a highly significant relative improvement in mental health."
"These findings raise the question of whether military deployment is necessarily bad for psychological health," the researchers said. "This study also reminds us that where there are highly selected forces with high morale involved in focused operations with positive outcomes, whatever the immediate political context, participation in war fighting may sometimes not necessarily be as deleterious to psychological well-being as has previously been thought."
A separate study in the same journal found that missing loved ones, rather than combat stress, appeared to be the main cause of psychiatric illness in troops. Researchers looked at the reasons for airlifting evacuees from Iraq on psychiatric grounds from the start of the build-up of UK forces in January 2003 until the end of October that year. Of 2,009 flown out, 178 were evacuated primarily for psychiatric reasons, but only three percent of these were suffering a combat stress reaction. The vast majority--more than 85 percent--were suffering from a low mood linked to separation from friends or family, or difficulties adjusting to the environment in Iraq.
Cuba develops new cholera vaccine
HAVANA
Cuban scientists have developed a new cholera vaccine and are ready to do "field testing" in Africa before it is marketed worldwide, officials said. The vaccine is derived from a live strain of a genetically modified bacillus that transmits cholera. It was successfully tested on 100 healthy subjects at Cuba's Instituto Finlay, said its vice president Francisco Dominguez.
"The research showed the antigen is safe and highly effective," Dominguez said.
The next step will be to test whether immunization with the new vaccine maintains its efficacy in countries that have high incidences of cholera, and where people have secondary conditions from malnutrition to malaria or AIDS, Dominguez said.
The Instituto Finlay has been behind a number of new vaccine developments. It developed the only effective vaccine against type B meningitis, which Cuba markets in several countries around the world.
Experimental vaccine proves effective v. shingles
WASHINGTON
An experimental vaccine has proved effective in a nationwide US study at combating the incidence and severity of shingles in older adults. The experimental vaccine was found to reduce the incidence of shingles by just over 50 percent during tests, according to the study published in the New England Journal of Medicine.
"These striking results indicate for the first time that we can use a vaccine to prevent shingles," said Stephen Straus, an infectious-diseases specialist at the National Institute of Allergy and Infectious Diseases and one of those who had overseen the trial. "This is very promising news for older persons."
The trial was conducted at 22 study sites across the United States between 1998 and 2001, and included 38,500 men and women aged 60 or older. Half of the study participants received a single injection of the zoster vaccine, while the other half received a placebo vaccine. During an average of more than three years of follow-up, the vaccine reduced the incidence of shingles by 51 percent, according to the study results.
China readies phase-II human trial on SARS vaccine
BEIJING
China is ready to begin the second phase of human trials on a vaccine for SARS after the first phase proved successful. Researchers want to sign up 300 volunteers for the next stage of testing the new medicine, the China Daily reported. The first phase of the trial began on 36 volunteers in May last year and by December SARS antibodies were found in all of them with no obvious side effects.
The new vaccine produced by Beijing's Sinovac Biotech Co. must go through three phases of trials before it can be licensed for human use. During the second phase, researchers hope to determine how long the antibodies remain in the volunteers and test the dosage.
Fuel cell runs on blood
TOKYO
A Japanese research team has developed a fuel cell that runs on blood without using toxic substances, opening the way for use in artificial hearts and other organs.
The biological fuel cell uses glucose with a nontoxic substance used to draw electrons from glucose, said the team led by Matsuhiko Nishizawa, bioengineering professor at the graduate school of Tohoku University. "Since the electron mediator is based on vitamin K3, which exists in human bodies, it excels in safety and could in the future generate power from blood as an implant-type fuel cell," the group said.
Most other bio-fuel cells under study use a metal complex, spawning concern over harm if used for implants. The newly developed cell, which is the size of a tiny coin, is able to generate 0.2 milliwatt of electricity, enough to power a device that measures blood-sugar level and transmits data elsewhere.
Placenta could provide alternative to stem cells
TAIPEI
Cells from the human placenta could provide an alternative to the ethically controversial fetal stem cells. A team of Taiwan scientists isolated "multipotent" cells from the placenta, which they described as "new type of cells" between embryonic and adult stem cells. The new cells are called placenta-derived multipotent cells (PDMCs).
"Unlike embryonic stem cells, PDMCs are free from ethical considerations," said Chen Yao-Chang, head of the National Health Research Institutes' (NHRI) Stem Cell Research Center.
They also have the advantage of being obtained through a noninvasive procedure compared with the painful operation required to obtain bone-marrow stem cells.
"The significance of the results is that it could provide another application option in future stem-cell therapy," Chen said. But he cautioned it could take some 10 years before the technology completes the required tests and clinical trials.
The research team has successfully used the technology and results have been published in an article titled "Isolation of Multipotent Cells from Human Term Placenta" in the journal Stem Cells.
The research team was composed of researchers from NHRI, Cathay General Hospital, National Taiwan University Hospital, and several other hospitals.
First step in interspecies transplants
SEOUL
South Korean scientists have discovered ways to prevent monkeys from rejecting organ transplants from pigs, paving the way for the use of animal organs and cells in humans and raising new hopes for millions of people needing heart, liver, and kidney transplants.
The study was led by Prof. Hwang Woo-Suk of Seoul National University whose team manufactured stem cells by cloning human embryos using human eggs from donors and skin cells from patients. The stem-cell research reported by the Korea Times marked a step forward in efforts to make it possible one day to transplant healthy cells into humans to replace cells ravaged by illnesses such as Parkinson and diabetes.
The Korea Times said the researchers hope to transplant hearts and insulin-producing cells from cloned miniature pigs into monkeys by the end of the year. "We have created dozens of pigs embedded with human immunity genes since late last year. We plan to start transplanting their organs or cells into monkeys as early as late this year," one of the researchers identified only as Kim said. The organs of pigs are almost the same in size as those of humans and their metabolic functions are also similar, he added.
Kim said Hwang would first transplant islets of Langerhans into monkeys. The research team then hopes to transplant pig organs into monkeys. To prevent rejection of the organs, Hwang's team cloned cells of sterilized pigs and transplanted them, along with human immunity genes, into piglets.
"We decided to begin with islets because transplanting cells have more chances of being usefully applied in the short term for many diabetes patients," Kim said. Islets are clusters of cells in charge of making blood sugar. "Even though we have come up with various ways to address negative immune responses, there's still a long way to go before clinically using the organs of other species," Kim said.
Trigger for stem-cell differentiation
SEOUL
A team of South Korean scientists said they had developed an efficient way of triggering stem cells to transform into specialist cells that can help the body repair itself. The team led by Moon Shin-Yong of the state-financed Stem Cell Research Center said they had found that the PDX-I protein produced in the human pancreas can work as an agent to trigger stem-cell differentiation.
By using the new method, they were able to direct human embryonic stem cells to develop into cells producing insulin.
The research is still at a preliminary stage, and researchers caution that although they can trigger differentiation, they have little or no control over what kind of mature cell the stem cell develops into. "Compared with conventional ways, this new method is highly efficient," researcher Kwon Young-Do said.
The success rate of the new method is about 70 percent while the traditional method that consists of gene manipulation is merely somewhere between one and 30 percent, according to Kwon.
Maggots perform "microsurgery"
SYDNEY
The ancient medical practice of using maggots to clean difficult wounds should be revived, according to an Australian study by Dr. Alvin Cham. The study showed that purpose-bred, sterile maggots can act as "microsurgeons" by eating only the dead tissue around slow-healing wounds. Cham said maggots may be especially useful for patients with diabetes or vascular disease because of difficulty in wound-healing and the added dangers posed by frequent surgery, as well as for those who have developed resistance to antibiotics.
In nine patients given larval therapy at the Royal Hobart Hospital, the maggots effectively cleaned all slow-healing wounds upon which they were placed--providing an additional option to surgical debridement.
"Maggots can do a better job of cleaning a wound because a surgeon can only rely on what their eye can see when cutting away dead tissue," Cham said. "These larvae only clean and eat what is dead and can act like a form of microsurgery." He said maggot therapy was especially useful in patients suffering from heart or lung disease, where ongoing surgery can present extra risks. They could even halt gangrene.
Patients in the study were not horrified at the treatment. "The patients seem to feel better about it than the people who are applying the therapy because they don't see it and feel only an occasional wriggling sensation," he said.
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