New corkscrew device reverses stroke
A revolutionary tiny corkscrew that captures blood clots from vessels deep inside the brain can “almost instantly” reverse damage caused by ischemic stroke, according to the first report on the safety and efficacy of the device presented today at the American Stroke Association’s 29th International Stroke Conference.
Ischemic strokes are caused by a blood clot that blocks blood supply to the brain. Each year, about 700,000 Americans suffer a stroke and 88 per cent of those strokes are ischemic, according to the American Stroke Association.
Blood clots causing stroke can be dissolved using the FDA-approved clot-busting drug tissue plasminogen activator (tPA) as standard therapy. But, it must be initiated intravenously within three hours (the earlier the better) of stroke onset to be effective.
The investigational device, the Concentric MERCI (Mechanical Embolus Removal in Cerebral Ischemia) Retrieval System, restored blood flow in 61 of 114 patients (54 per cent) in Phase I and II of the MERCI trials, which studied patients up to eight hours after initial stroke symptoms who were not eligible for standard tPA therapy, said principal investigator Sidney Starkman, MD, Professor of Emergency Medicine and Neurology at the University of California, Los Angeles (UCLA) and Co-Director of the UCLA Stroke Center.
Restoring blood flow in these trials reversed paralysis and other stroke symptoms, Starkman said.
“How often do we get a chance to reverse a patient’s stroke on the table? We have had patients completely paralysed on one side of their body, who were made normal almost instantaneously when the clot was retrieved,” he said.
The MERCI Retrieval System is inserted into an artery in the groin, and then carefully guided via standard angiography into the brain until it reaches the blood clots. The device is made from a combination of nickel and titanium, “which is unique in that it allows the device to have a ‘memory.’ So in this case, when it is deployed, it ‘remembers’ to form itself into a helical shape, like a corkscrew,” Starkman said.
Once the device “captures” the blood clot, the device and clot are withdrawn into a larger catheter with a balloon. During the evacuation process, the balloon is briefly inflated to momentarily stop blood flow so the clots can be safely removed. Starkman added that the retrieval procedure can only be performed by a highly trained team at specialised centres.
“Thus far, we have seen that the MERCI Retrieval System is quite safe and we believe it holds great promise, but more research is needed to refine the device and study its effectiveness,” Starkman said.
Child asthma study
A recent study has found that infective episodes during pregnancy may be associated with atopic and nonatopic asthma in children.
The case-controlled study, reported in the January edition of Allergy, included 338 children with asthma and 467 healthy controls. Parents were asked to complete a questionnaire detailing any fever episodes, flu episodes, threatened abortions or drug factors that occurred during the pregnancy. Children in the study were given skin-prick tests to 10 allergens to determine atopy.
Flu episodes that occurred during pregnancy were significantly associated with the development of asthma, especially nonatopic asthma. Fever episodes during pregnancy were associated with the development of both atopic and nonatopic asthma. Both flu and fever episodes seemed to have the greatest effect if they occurred during the third trimester of pregnancy.
The authors emphasised the need for larger, prospective studies to confirm their results.
Gulf war syndrome case fails
Recent media reports indicated that a legal battle by Gulf war veterans who claim they were made ill by the conflict was set to collapse.
According to one report the veterans’ own solicitors said that, despite a publicly funded probe, they could not uncover enough evidence that “Gulf war syndrome” existed.
Their finding was likely to mean that legal aid would be withdrawn from the eight-year bid for compensation.
The National Gulf Veterans’ and Families Association says there remains a case to answer, and plans an appeal.
The BBC quoted one of the solicitors, Patrick Allen, as saying the government should now consider ex gratia payments to settle the issue.
The problem for scientists is trying to establish a cause for the variety of symptoms reported by veterans. Many of these are experienced regularly by the general population, and linking them directly to any particular exposure to chemicals or vaccines during the conflict - as has been alleged - is extremely difficult, the BBC reported.
Mice produce monkey sperm
US scientists say they have been able use mice to produce viable monkey sperm using tissue transplanted from the testes of macaques. The implications are that it might also be possible to grow human sperm in mice.
The researchers, from the universities of Pennsylvania and California, report their studies in a recent issue of the journal Biology of Reproduction.
The procedure involves transplanting a tiny amount of testicular tissue from an immature rhesus macaque monkey under the skin of a lab mouse. After seven months, the testes grafts were seen to produce viable sperm.
According to the researchers the technique could produce offspring from other endangered species or valuable livestock. And if human sperm were produced, although they pointed out this would be a controversial move, the technique could provide a way of testing toxins or male contraceptive drugs on sperm development.
Scientists clone 30 human embryos
South Korean scientists, led by Seoul National University’s Woo Suk Hwang, have cloned 30 human embryos to obtain stem cells they hope could be used to treat disease.
Details of the research were published online by the journal Science.
No research group has reported producing so many early-stage clones and seen their development progress to such an advanced stage.
The team says it sought approval for its work from an ethical review board and obtained informed consent from its women donors before proceeding with the work. Thirty embryos - exact genetic copies of their female donors - were then cultured to the so-called blastocyst stage at which stem cells could be extracted.
The intention of the research is to study human embryonic stem cells to see how they could be used as a therapeutic tool to treat disorders, such as diabetes, osteoarthritis, and Parkinson’s disease, among others, in which tissues in the body have begun to fail.
Professor Hwang, an expert in animal cloning, told the BBC that any attempt to produce a baby would be “crazy”.
“We will never try to produce cloned human beings,” he said.
“During animal cloning, we experienced so many difficulties and dangers with deformities, especially in the internal organs.”
New cancer scan
A new type of brain scan could tell doctors whether or not a cancer treatment is working weeks earlier than is currently possible, researchers reported recently in the British Journal of Cancer.
Scientists found the technique - known as nuclear magnetic resonance (NMR) - was able to predict at an early stage how a brain tumour, called a glioma, was responding to treatment with the drug temozolomide.
A team of researchers studied temozolomide (Temodal) - a chemotherapy drug developed by Cancer Research UK which works by causing lethal DNA damage in cancer cells.
Doctors currently learn whether or not the drug is proving effective in a patient by monitoring the size of tumours after months of treatment. Now researchers have found they could get this information much more quickly by using a sophisticated machine to monitor subtle chemical changes in tumours brought about by temozolomide.
Study author Dr Andrzej Dzik-Jurasz, Honorary Senior Lecturer at The Institute of Cancer Research, explains: “NMR has been used in laboratories for over 40 years to determine the chemical structure of molecules. Although the technique has been used in cancer research for a number of years, this is the first attempt to use it to monitor the action of a drug within a low-grade brain tumour.”
Fellow author Professor Martin Leach, of the Cancer Research UK Clinical Magnetic Resonance Research Group at The Institute of Cancer Research, said: “NMR could help doctors identify different types of gliomas and learn about their interactions with drugs by looking directly at cancer cell behaviour. They could then predict which tumour types are likely to respond to treatments before giving them to patients.”
Smoking harms foetuses
A report by the British Medical Association says smoking damages almost all aspects of sexual, reproductive and child health.
It is responsible for up to 5,000 miscarriages a year, reduces the chances of successful IVF and is implicated in cases of cervical cancer. It adds that smoking reduces the chances of a woman conceiving by up to 40 per cent per cycle
The report says the damage inflicted by smoking is evident throughout reproductive life - from puberty to middle age.
There is also evidence that smoking may increase the risk of certain foetal malformations, such as cleft lip and palate.
Women who smoke have also been found to produce smaller volumes of lower quality breastmilk.
Passive smoking is linked to cot death, premature birth, respiratory infection in children and the development of childhood asthma.
Researchers writing in the journal Science say they have found a predatory bacterium that may be able replace antibiotics which are steadily decreasing in effectiveness.
The researchers from the Max-Planck Institute of Developmental Biology and Nottingham University say the Bdellovibrio bacterium could be harnessed to tackle infections.
Although the bacterium has been know for some time, it’s potential to fight infection had not been investigated.
According to a report on BBC News Online, the scientists have mapped the complete genome of the bacterium.
They say the bug finds its prey by sensing chemicals it emits and then swims at high speed towards the target before attaching itself to the prey cell, cutting a hole in the cell wall, entering the cell and then consuming it from the inside.
Bdellovibrio does not infect mammalian cells, so it is potentially safe to use in humans, although there is still more research that needs to be done.
Illicit kidney trade scandal
South African media report that the Israeli Government has been dragged into an international kidney transplant trafficking scandal, with claims that it financed the illegal operations done at St Augustine’s Hospital in Durban, South Africa, through its own state healthcare schemes.
According to reports a syndicate recruited kidney donors from Brazil and paid them about US$10,000 to come to Durban to donate a kidney.
The organs were then transplanted into Israeli recipients, who apparently paid the syndicate up to $120,000 for the flights, accommodation, operations and the organs.
All the operations - about 80 in the past two years - were done by surgeons at St Augustine’s Hospital.
The scandal came to light late last year with the arrest of Israeli kidney recipient Agania Robel.
In a guilty plea before a Durban magistrate, Robel admitted to paying $45,000 for the kidney, which was donated by Brazilian Rogerio Bozzera da Silva, who had been paid $6,000 for it.
He revealed that an insurance claim was to be instituted in Israel in connection with the operation.
Roderick Kimberley, the Durban co-ordinator of the syndicate, also pleaded guilty and said he had been recruited by an Israeli government official called Ilan Perry to look after the donors and recipients while they were in Durban.
In Brazil, retired Israeli army officer Geldaya Tauber Gady, under arrest in that country for belonging to the international trafficking ring, also mentioned “Ilan”, as the man who had put him in touch with an intermediary in Brazil.
According to reports, he told the court: “The Israeli Government is aware of the traffic in organs for patients in its country and pays for all the transactions through four health plans. I never thought the government was financing anything illegal. I was only helping people in need.”
And in Israel it is reported that Perry has been arrested for tax evasion. The Israeli Government claims he owes it $5 million.
South African police say the investigation is ongoing.
WHO warns against xenotransplantation
The World Health Organ-isation (WHO) has warned that pioneering research into organ transplants from animals to humans must urgently be regulated to prevent diseases jumping the species barrier in a similar manner to Severe Acute Respiratory Syndrome (SARS).
WHO officials said the experimental transplants were on the verge of going ahead in some countries, but there was little regulation to keep track of what is going on or to prevent the misuse of xenotransplantation or animal-to-human transplants.
Alex Capron, WHO Director of Ethics, Trade, Human Rights and Law, said: “The risks in terms of immune reactions and the transfer of animal patho-gens to not only the individual recipient, but potentially in to the general population as we saw with SARS ... pose as of yet unquantified risks.”
The WHO wants its 192 member states to stop xenotransplantation until they have a regulatory framework, which barely exists anywhere at the moment according to Capron.
Men try out ‘male pill’
German pharmaceutical company Schering AG said recently that it and Dutch firm Organon had started mid-stage trials on a contraceptive injection for men that could be the next step towards the elusive “male pill”.
Schering said trials of the drug, which is a combination of an implant and an injection, would be conducted on 350 men at 14 centres across Europe, and would be completed by December 2005.
X-rays increase cancer risk
Researchers from Oxford University and Cancer Research UK say that about 0.6 per cent of total cancer risk may be due to exposure to x-rays in hospitals.
They warn that doctors should avoid “unnecessary” x-rays and CT scans.
The report, published in the Lancet medical journal, says worldwide, x-rays ac-count for approximately 14 per cent of the general population’s exposure to radiation from both man-made and natural sources. However, the proportion of cancers deemed to be caused by x-rays varies widely from country to country.
In the UK studies have shown up to 30 per cent of chest x-rays are unnecessary.