domingo, 26 de fevereiro de 2012

Médicos pediatras devem recusar clientes que não aceitam vacinar seus filhos?




Neste artigo publicado na Forbes, a opinião da maioria dos consultados é dispensar pacientes que se recusam a vacinar seus filhos, uma vez dadas todas as explicações sobre os benefícios das vacinas, incluindo informá-los sobre dados falsos publicados sobre vacina e Autismo.                                Should Doctors Fire Their Anti-Vaccine Patients?

The anti-vaccination movement continues to grow, despite the retraction and thorough discrediting of the 1998 scientific study that spurred much of its growth.  The stubborn persistence of anti-vaxxers shows how difficult it is to dispel misinformation once that information is out there, even after dozens of new studies and millions of dollars in research that demonstrate that vaccines are safe.
One of the most dangerous trends is the growing number of parents who refuse to vaccinate their kids, or who choose “alternative” vaccine schedules, such as the one promoted aggressively by Robert Sears (who goes by “Dr. Bob”).  Sears appears to have simply invented this alternative schedule without bothering to conduct any scientific studies, in part to promote sales of his 2007 book, The Vaccine Book: Making the Right Decision for Your Child.  Vaccine expert Dr. Paul Offit explained, in a 2009 article in the journal Pediatrics, why Dr. Sears’ schedule was a very poor choice for children and for the public health.  After thoroughly dismantling Sears’ anti-science positions, Offit concludes, “Sears has a poor grasp of the scientific method.”  That’s an understatement.
Other doctors, perhaps jealous of all the attention that Sears has gained through his anti-vaccine writings and television appearances, have created their own alternative vaccine schedules.  One of them, Donald Miller, even goes so far as to say that vaccines cause childhood cancer, despite the complete lack of evidence for this wild claim.  Somehow Sears, Miller, and others like them have managed to convince many parents that their children don’t need vaccines.
In response to parents who don’t want to vaccinate, many of whom show up with Dr. Bob’s schedule in hand, pediatricians have struggled to find an effective response.  Parents can be utterly convinced by the misinformation they find on the Internet, which is all too easy to find.  (For example, Googling “vaccine” brings up the National Vaccine Information Center, a hotbed of anti-vaccine propaganda and pseudoscience, on the first page of hits.)  By the time parents arrive with their babies for the first vaccine, convincing them to change their minds can be nearly impossible.
Perhaps in frustration, doctors have started to “fire” their patients if they refuse to vaccinate.  As reported by Shirley Wang in The Wall St. Journal last week, 20-30% of doctors in two different surveys, in Connecticut and the Midwest, reported having to kick patients out of their practices because of vaccine refusal.  These numbers have roughly doubled over the past ten years, according to the American Academy of Pediatrics.
Is firing a patient the right thing to do? It’s a difficult question.  On the one hand, doctors should do everything they can to make sure kids are vaccinated.   If a doctor kicks a parent out, that parent may find another doctor who doesn’t insist on vaccinating children, which ultimately harms the children.  Doctors have to spend more time educating parents about the tremendous benefit of vaccines, about the very strong evidence (based on tens of millions of doses) for vaccine safety, and about the frightening consequences of infection with meningitis, hepatitis, measles, polio, and other vaccine-preventable diseases.
On the other hand, unvaccinated children bring diseases into the pediatrician’s office, where they can spread them to other children.  Some of these other children are too young to be vaccinated, and childhood infections can be extremely dangerous, even fatal, in the very young.  From this perspective, “firing” a patient might be the only responsible action, after first trying to convince the parents to vaccinate.  I know that I wouldn’t want to bring my child to a doctor’s office where unvaccinated children were in the same room.
I understand how nervous a parent can be about vaccinations.  I will never forget the day my older daughter got her first vaccine: the needle looked huge compared to her tiny leg, and she screamed when the doctor gave her the shot.  But she was fine a few minutes later, and she’ll be protected against a dangerous infection for her entire life.  Vaccines have been so successful at eliminating childhood infections that parents no longer see these infections as a threat.  Ironically, the very success of vaccines has allowed the anti-vaccine movement to sway so many people.
Doctors may have to keep firing the parents of their young patients, but I hope they’ll first make every effort to educate them.  They need to explain that vaccines do not cause autism, nor do the ingredients in vaccines, and that scientific studies involving hundreds of thousands of patients support these conclusions.
They should also explain that many of the anti-vaccination claims on the Internet started when Andrew Wakefield published one small study of 12 patients, now retracted, claiming a link between the MMR vaccine and autism.  Investigations later revealed that he was paid a large sum of money to recruit patients for a lawsuit against vaccine makers, that he didn’t reveal these payments to his co-authors or the patients, and that he manipulated the data.  Since then, the anti-vaccine movement has exploded and we’ve experienced multiple outbreaks of measles, mumps, and other illnesses linked directly to unvaccinated children.
Doctors interviewed by the Wall St. Journal reported that they had convinced at least some parents to follow the recommended vaccine schedule.  Perhaps that’s the best we can hope for.  If we’re going to avoid a return to the era when children routinely died from infections, we must keep trying.

Salvador, Carnaval e Copa do Mundo- Financial Times



World Cup vs glorified street party

“We are definitely prepared for the World Cup,” said Merina Aragao, a tourism official in Salvador, the northeastern city with Brazil’s second-largest Carnival celebrations behind Rio de Janeiro. “After organizing this grandiose party which is the Carnival in Salvador, we will certainly be able to handle the challenges of the World Cup.”
That’s from an Associated Press story on Thursday. You have to ask whether officials might have got a bit carried away by the past week’s party mood.
Not that holding a carnival is any small achievement. The exuberant parades put on by samba schools that dominate carnival in Rio de Janeiro and São Paulo are immense feats of organisation. Scores of people from local communities work together for months to create fabulous floats and costumes. Drum sections are big, powerful and highly sychronised. Dancers learn intricate choreographies, and supporters and members of the public are corralled into what look like well-rehearsed presentations that come together often literally at the very last minute.
Those involved are deeply dedicated. As Lourival Almeida, carnival director of the Vai-Vai samba school in São Paulo, told the FT before the 2010 carnival: “The most important thing that every company wants of its customers and its workers, is loyalty, love for the brand,” he says. “Samba schools have this to spare. People dedicate themselves out of love.”
Carnival in Brazil’s north-east is no less exuberant, though here it is more a matter of following the trio elétrico, an amplified band on the back of a truck.
Whatever the style, though, carnival celebrations are street parties that generations of local people have been putting together since the late 19th century. That’s not quite the same as organising a world football tournament. The latter will involve a bit more than putting people up in hotels, caring for them when they get sick and cleaning up after them (though it will involve all that, too).
Officials from around Brazil have pointed to their success in providing health, security and cleaning services during the long carnival weekend. That’s not what this commentator had to say about the Rio carnival on a readers forum run by the Esatado de S. Paulo newspaper:
Patients complain about the lack of beds in public hospitals. A great exercise for the 2014 World Cup and other events. What we need, urgently, is to improve services at Rio de Janeiro’s hospitals, because the quality of service is very bad and the number of patients can only increase. Carnival is an excellent test of all the essential services in the city, which also needs to urgently review the supply of public toilets and avoid this scandal of people urinating everywhere without a minimum of respect. The time is now.
Brazil has all of two years to get ready for the World Cup, and another two years for Rio to be ready to host the 2016 Olympic Games. President Dilma Rousseff is well known for knocking heads together when public works get behind schedule. By now, heads should be aching up and down the country.

sábado, 25 de fevereiro de 2012

Cada dia fica mais facil, barato e rápido sequenciar um genoma

Technology that its parent company says will sequence a human genome in just 15 minutes opened its first data run to scrutiny today.

Oxford Nanopore Technologies, based in Oxford, UK, revealed the initial results from its GridION system at the Advances in Genome Biology and Technology meeting in Marco Island, Florida. The firm expects to start selling its new machine in the second half of this year and also plans to launch the world’s first miniaturized, disposable sequencer — the MinION — which will retail for less than US$900.


Fast track: nanopore sequencing identifies individual bases as a strand of DNA is passed through a pore.
IEMEDIA SOLUTIONS
Given its flexibility, scalability and low entry price, “this technology could have a seriously disruptive effect on the sequencing industry,” says Daniel MacArthur, a geneticist who blogs about the genomics industry.

That industry is already seeing significant jockeying for position with Swiss drug giant Roche last month launching a takeover bid for the manufacturer of the sector’s dominant technology: Illumina of San Diego, California (see Roche takeover bid poses challenge to Illumina). In the same month, up-and-coming company Ion Torrent Systems of Guilford, Connecticut, vowed to begin selling a machine by the end of the year that can sequence an entire human genome in a day for less than $1,000 per sequence.And last April, Pacific Biosciences of Menlo Park, California, launched its own sequencing technology.

Oxford Nanopore’s system uses nanopore sequencing to rapidly read DNA sequences. A strand of DNA is fed through a biological pore and the various bases are identfied by measuring the difference in their electrical conductivity as they pass through the pore (see Personal genomes: Standard and pores).

Related stories
Roche takeover bid poses challenge to Illumina
Genome sequencing: the third generation
Personal genomes: Standard and pores
More related stories
The launch of the nanopore machines marks the end of a decades-long wait. Nanopore technology was first mooted in the early 1990s, and as it has taken so long to get to the market, many scientists have reserved judgement on the technique’s capabilities until they can see the results for themselves. But upon seeing some of the data presented today, some scientists, at least, are cautiously enthusiastic, in part because, they note, Oxford has refrained from hyping its technology until now.

“I think it is all credible,” says Chad Nusbaum, co-director of the Genome Sequencing and Analysis Program at the Broad Institute in Cambridge, Massachusetts. “I would bet they are even underplaying it because they don't want to risk overpromising. It is attractive in that it could put pressure on the market to innovate and lower prices.”

That first taste of sequence arrived in the shape of the genome of a virus, the Phi X phage. Clive Brown, chief technology officer at Oxford Nanopore, told today’s meeting that the company’s system can sequence the entire 5.4-kilobase genome of the virus in one continuous read. However, the machines being launched later this year will initially aim to deliver reads of 100 kilobases. That is still much longer than the fragments typically delivered by today’s machines, and so should provide a more accurate picture of a genome’s true structure, by allowing researchers to generate continuous sequences of regions that now are read out as short pieces of DNA, Brown said.

Strand and deliver
The potential advantages of the nanopore system are that it could deliver real-time seqeuncing of single molecules at low cost, and should not damage the DNA, so in theory the same molecule can be reanalysed, said Brown.

The Oxford machines will be configured as scalable computer clusters, so that new ‘nodes’ can be added to them, so that users can customize the machines. The initial system will feature a nodes containing 2,000 nanopores that can read DNA at a rate of hundreds of kilobases per second, the company said. Next year, the company will begin selling nodes containing 8,000 nanopores; 20 of these combined would theoretically be able to sequence an entire human genome in 15 minutes, says Gordon Sanghera, Oxford’s chief executive.

Sanghera, adds that the company’s systems will be priced such that large genome centres would pay $25 to $40 per gigabase of sequence this year. That would mean a cost of just a few thousand dollars to sequence a human genome to the standard 30-fold coverage.

The technology has a 4% error rate, meaning that 4% of the bases are read incorrectly, but Brown says that the company is working to cut this down to 0.1– 1% by the time the system launches, which would make it more competitive with current systems.

It is unclear how Oxford Nanopore will affect the landscape of companies that are already pushing genomics into the clinic (see Sequencing set to alter clinical landscape). The firm has not released any data sequenced from human genomes, so it is unclear how its technology would perform with genomes more complex than those of viruses. (The human genome contains more than 3 gigabases of DNA.)

"It's a long way from Phi X to routine human genomes at the accuracy and completeness that are now needed as this moves to the clinic,” says Kevin Ulmer, who has worked in the sequencing industry for decades. “We'll need to see more from sequencing large, complex genomes and then understand the real cost comparison with other platforms.”

quinta-feira, 16 de fevereiro de 2012

Estudantes de Medicina não sabem lavar as mãos na Alemanha


German medical students need hand holding for hand washing
By: Emilie Green


Four out of five medical students do not know when to clean their hands in a clinical setting, show the results of a survey.

For the survey, by a team at Hannover Medical School in Germany, 85 third year medical students were presented with clinical scenarios that either warranted or did not warrant the use of alcohol hand gel. Overall, 79% failed to recognise the correct indications for using the gel.

Many of the students surveyed believe that good hand hygiene is inversely proportional to the level of training and increasing age of the physician responsible for training students. Those predominantly responsible for training medical students might not be setting a good example.

Karolin Graf, one of the study authors, suggests that senior healthcare professionals need to set a good example, “There is no doubt that we need to improve the overall attitude toward the use of alcohol-based hand rub in hospitals. To achieve this goal, the adequate behaviour of so-called “role models” is of particular importance,” she said.

Despite the initiation of the German Clean Hands Campaign in 2008, this study shows that hand hygiene remains inadequate. The authors recommend adapting the six year medical degree programme so that students are educated on infection control issues more often and in more detail.

A report published in June 2009 by the National Audit Office said doctors working in UK hospitals are less likely to comply with good infection control practice than nurses. The report also states that some doctors, particularly those in their foundation years, remain unaware of the link between hand hygiene and hospital-acquired infections.

quarta-feira, 15 de fevereiro de 2012

Células tronco contribuem com a saúde do coração


Bone marrow stem cells give 'some' heart healing
By James Gallagher
Health and science reporter, BBC News

Scar tissue forms after a heart

Cells 'heal' heart attack scars
Hearts made to repair themselves
Stem cell hope for heart patients
Bone marrow stem cell therapy offers "moderate improvement" to heart attack patients, according to a large UK review of clinical trials.

The analysis by the Cochrane Collaboration looked at 33 trials involving more than 1,700 patients.

It said longer-term studies were needed to see if the experimental therapy affected life expectancy.

The review comes a day after doctors reported the first case of using heart cells to heal heart attack damage.

If a patient survives a heart attack, dead heart muscle is replaced with scar tissue - leaving the patient weaker and possibly on a lifetime of medicine.

Researchers are beginning to show that taking cells from a heart, growing millions of new heart cells in the laboratory and pumping those back into the heart may reduce scar tissue and lead to new heart muscle.

Stem cell therapy may also reduce the number of patients who later die or suffer from heart failure, but currently there is a lack of statistically significant evidence based on the small number of patients treated so far”

Dr Enca Martin-Rendon
Lead researcher
However, the trials are at a very early stage and in only a handful of patients. Using a similar technique with cells taken from the bone marrow, which is a prime source of stem cells, has a much longer pedigree.

The report by Cochrane pooled the data from all 33 bone marrow trials which had taken place up to 2011.

It concluded that bone marrow therapy "may lead to a moderate long-term improvement" in heart function which "might be clinically very important".

Longer life uncertain
It said there was still no evidence of "any significant effect on mortality" in comparison with standard treatment. However, this may be due to the size of the studies and that patients were followed for a short period of time.

Lead author Dr Enca Martin-Rendon, from NHS Blood and Transplant at the John Radcliffe Hospital in Oxford, said: "This new treatment may lead to moderate improvement in heart function over standard treatments.

"Stem cell therapy may also reduce the number of patients who later die or suffer from heart failure, but currently there is a lack of statistically significant evidence based on the small number of patients treated so far."

Prof Anthony Mathur, from Barts and the London School of Medicine and Dentistry, is leading the largest ever trial of stem cells in heart attack patients.

It starts this year, however, he told the BBC that the results could come quite quickly. Three thousand patients across Europe will take part. They will be injected with stem cells five days after a heart attack and then followed for two years to see if the therapy affects life expectancy.

Prof Peter Weissberg, medical director at the British Heart Foundation, said: "This review reflects the consensus of opinion about these trials - cell therapy has a modestly beneficial effect.

"Despite that, no-one knows why, or even if, cell therapies will translate into better survival or sustained improvement in damaged hearts. It's much too early to judge the likely long-term benefits."