Medicina está sendo reduzida às questões econômicas

Segundo os pesquisadores, essa redução da Medicina à Economia vai afastar profissionais realmente focados no humanismo, transformando os profissionais da saúde em burocratas seguidores de regras pré-estabelecidas para darem maior lucro.

Fornecedores e clientes

Em uma denúncia contundente e alarmante, dois médicos britânicos alertam que a Medicina está sendo reduzida às questões econômicas.

Os médicos, que antes precisavam aprender apenas a linguagem médica, agora devem também lidar com um mundo da saúde que transformou hospitais em fábricas e consultas médicas em transações econômicas.

"Os pacientes não são mais pacientes, são 'consumidores' ou 'clientes'. Os médicos e enfermeiros foram transformados em 'fornecedores'," afirmam Pamela Hartzband e Jerome Groopman em um artigo no conceituadoNew England Journal of Medicine.

Soluções de prateleira

Segundo os estudiosos, as reformas dos sistemas de saúde que estão ocorrendo no mundo todo estão permitindo que economistas e políticos estabeleçam que os cuidados aos pacientes devam ser "industrializados e padronizados".

"Os hospitais e clínicas devem funcionar como fábricas, e termos arcaicos, como doutor, enfermeira e paciente devem ser assim substituídos por uma terminologia mais adequada a essa nova ordem," escrevem eles.

O problema, segundo os autores, é que o conhecimento especializado que os médicos e enfermeiras têm e usam para ajudar os pacientes a entenderem as razões de duas doenças e os tratamentos disponíveis está se perdendo em um sistema em que tudo deve depender de "soluções de prateleira", que pretendem substituir a "prática baseada em evidências" pelo "julgamento clínico".

Curandeirismo moderno

"Reduzir a medicina à economia faz uma paródia do vínculo entre o curandeiro e os doentes," escrevem os pesquisadores.

"Por séculos, os médicos mercenários têm sido publicamente e devidamente castigados. Esses médicos traem seu juramento. Devemos nós agora elogiar o médico cuja prática, como um negócio bem-sucedido, maximiza os lucros obtidos de seus 'clientes'?" questionam eles.

Nesse novo mundo da "Medicina Econômica", economistas e políticos querem que a prática da Medicina se reduza a seguir alguns manuais de instruções contendo orientações pré-estabelecidas.

Mas essas orientações, argumentam os estudiosos, são preferências subjetivas escolhidas por quem elabora as normas, e não conclusões científicas.

Normas subjetivas

Eles citam como exemplo o fato de que diferentes grupos de especialistas traçam guias de orientação diferentes partindo dos mesmos dados e dos mesmos experimentos científicos.

E isso em questões que vão dos cuidados com a hipertensão e o colesterol alto até os exames preventivos para câncer de próstata e câncer de mama.

Nos casos dos cânceres de mama e próstata, por exemplo, inúmeros estudos afirmam que o rastreamento não produz os benefícios apregoados, mas as organizações médicas orientam exames cada vez mais precoces.

Quando são colocados para debater, a discussão dá razão aos dois estudiosos, acabando em questões econômicas: os defensores de uma posição dizem que os outros querem ganhar dinheiro com mais exames, enquanto os defensores da outra posição dizem que o outro lado quer economizar dinheiro para os planos de saúde.

E os estudos científicos são deixados de lado.

Usurários da Medicina

Mais problemática ainda, afirmam os dois estudiosos, é o impacto do novo vocabulário sobre os futuros médicos, enfermeiros, terapeutas e assistentes sociais.

"Quando nós mesmos ficamos doentes, nós queremos alguém cuidando de nós como pessoas, não como clientes que estão pagando, e para individualizar nosso tratamento de acordo com nossos valores," escrevem eles.

Segundo os pesquisadores, essa redução da Medicina à Economia vai afastar profissionais realmente focados no humanismo, transformando os profissionais da saúde em burocratas seguidores de regras pré-estabelecidas para darem maior lucro.

Lesão medular contornada por estimuladores acionados por luz

Cada microestimulador é feito de um material semicondutor, semelhante ao usado na fabricação de processadores de computador.

Estimulação por luz

Cientistas estão testando um minúsculo estimulador, acionado por luz, que pode ajudar pessoas paralisadas por lesão medular a recuperarem parte dos movimentos.

Mesut Sahin e seus colegas do Instituto de Tecnologia de Nova Jérsei (EUA) afirmam que seus dispositivos sem fios (wireless) poderão ser úteis para pacientes com lesão na medula espinhal.

A tecnologia foi batizada de FLAMESfloating light activated micro-electrical stimulators, estimuladores microelétricos flutuantes ativados por luz, em tradução livre.

Microestimuladores medulares

Cada microestimulador é feito de um material semicondutor, semelhante ao usado na fabricação de processadores de computador.

Cada microestimulador é implantado em um ponto da medula, logo abaixo da lesão. O termo flutuante no nome da tecnologia refere-se ao fato de que cada um deles fica "solto", ou seja, pode mover-se pelo tecido.

Depois de implantados, os estimuladores são ativados por um feixe de luz infravermelha disparada por um laser através de uma fibra óptica.

Como a ativação é feita por luz, não há fios de interligação, o que torna este um implante wireless.

Movimentos computadorizados

Controlando a intensidade da luz, os pesquisadores demonstraram que é possível energizar os microestimuladores que, por sua vez, acionam os nervos na medula espinhal exatamente abaixo do ponto da lesão.

Isto permite movimentar os músculos que estavam paralisados - tudo o que um paciente terá que fazer será apertar um botão ou dar um comando de voz para acionar o laser infravermelho e ativar o microestimulador desejado.

Futuramente, esse controle poderá ser computadorizado, para permitir movimentos ritmados, como andar ou mover os braços de forma controlada.

Recuperação de movimentos

"Nossos testes in vivo sugerem que a tecnologia Flames pode ser usada para estimulação intra-espinhal mesmo nos pontos mais profundos do implante," afirma Sahin.

Os testes in vivo foram feitos em cobaias, o que é a última etapa antes que uma tecnologia possa ser testada em seres humanos.

"Nós esperamos que, assim que a Flames avance para o estágio clínico, os pacientes paralisados por lesão medular possam recuperar funções vitais," afirmou Sahin.

Perinatal Antidepressant Stunts Brain Development in Rats; Miswired Brain Circuitry Traced to Early Exposure

ScienceDaily (Oct. 24, 2011) — Rats exposed to an antidepressant just before and after birth showed substantial brain abnormalities and behaviors, in a study funded by the National Institutes of Health.

Cross-sections of the part of the rat brain that connects the left and right hemisphere (corpus collosum) show stunted development of neuronal wiring, called axons, in an animal that received an antidepressant (right) during a critical period around the time of birth. A protective sheath, called myelin (visible in normal animal at left), that normally wraps the axons and boosts their efficiency, failed to develop normally in the treated animal. The resultant inefficient neuronal communications could underlie the pattern of deficits seen in autism. 

After receiving citalopram, a serotonin-selective reuptake inhibitor (SSRI), during this critical period, long-distance connections between the two hemispheres of the brain showed stunted growth and degeneration. The animals also became excessively fearful when faced with new situations and failed to play normally with peers -- behaviors reminiscent of novelty avoidance and social impairments seen in autism. The abnormalities were more pronounced in male than female rats, just as autism affects 3-4 times more boys than girls.

"Our findings underscore the importance of balanced serotonin levels -- not too high or low -- for proper brain maturation," explained Rick Lin, Ph.D., of the University of Mississippi Medical Center, Jackson, a Eureka Award grantee of the NIH's National Institute of Mental Health.

Lin and colleagues report on their discovery online during the week of Oct. 24, 2011, in the Proceedings of the National Academy of Sciences.

Last July, a study reported an association between mothers taking antidepressants and increased autism risk in their children. It found that children of mothers who took SSRI's during the year prior to giving birth ran twice the normal risk of developing autism -- with treatment during the first trimester of pregnancy showing the strongest effect. A study published last month linked the duration of a pregnant mother's exposure to SSRIs to modest lags in coordination of movement -- but within the normal range -- in their newborns.

"While one must always be cautious extrapolating from medication effects in rats to medication effects in people, these new results suggest an opportunity to study the mechanisms by which antidepressants influence brain and behavioral development," said NIMH Director Thomas R. Insel, M.D. "These studies will help to balance the mental health needs of pregnant mothers with possible increased risk to their offspring."

Earlier studies had hinted that serotonin plays an important role in shaping the still-forming brain in the days just after a rat is born, which corresponds to the end of the third trimester of fetal development in humans. Experimental manipulations of the chemical messenger during this period interfered with formation of sensory-processing regions of the cortex, or outer mantle, and triggered aggressive and anxiety-related behaviors in rodents.

There is also recent evidence in humans that serotonin from the placenta helps shape development of the fetal brain early in pregnancy. Disrupted serotonin has been linked to mood and anxiety disorders. SSRIs, the mainstay medication treatment for these disorders, boost serotonin activity.

Lin and colleagues gave citalopram to male and female rat pups prenatally and postnatally and examined their brains and behavior as they grew up. Male, but not female, SSRI exposed rat pups abnormally froze when they heard an unfamiliar tone and balked at exploring their environment in the presence of unfamiliar objects or scents. These behaviors persisted into adulthood. The male pups especially also shunned normal juvenile play behavior -- mimicking traits often seen in children with autism.

A key brain serotonin circuit, the raphe system, known to shape the developing brain during the critical period when the animals were exposed to the drug, showed dramatic reductions in density of neuronal fibers. Evidence of stunted development in the circuit coursed through much of the cortex and other regions important for thinking and emotion, such as the hippocampus.

The researchers also discovered miswiring in the structure responsible for communications between the brain's left and right hemispheres, called the corpus collosum. Extensions of neurons, called axons, through which such long-distance communications are conducted, were deformed. A protective sheath, called myelin, that normally wraps and boosts axons' efficiency-- like insulation on an electrical wire -- was reduced by one-third in the treated animals. This damage was three times worse in male than in female pups and would likely result in abnormal communication between the two hemispheres, say the researchers.

Moreover, the perinatally exposed animals showed evidence of neurons firing out of sync and other electrophysiological abnormalities, suggesting faulty organization of neuronal networks in the cortex.

The research also was supported by the NIH's National Center for Research Resources, National Institute of Neurological Disorders and Stroke and National Institute of Child Health and Human Development.

Hold Your Forces: Mechanical Stress Can Help or Hinder Wound Healing Depending On Time of Application

ScienceDaily (Oct. 24, 2011) — A new study demonstrates that mechanical forces affect the growth and remodeling of blood vessels during tissue regeneration and wound healing. The forces diminish or enhance the vascularization process and tissue regeneration depending on when they are applied during the healing process.

Micro-computed tomography reconstructions of bone formation (left) when the injury site experienced no mechanical force for seven weeks and (right) when mechanical forces were exerted on the injury site beginning after four weeks for a duration of three weeks. Study results showed that bone formation improved by 20 percent with delayed loading compared to when no force was applied, and strong tissue biomaterial integration was evident.

The study found that applying mechanical forces to an injury site immediately after healing began disrupted vascular growth into the site and prevented bone healing. However, applying mechanical forces later in the healing process enhanced functional bone regeneration. The study's findings could influence treatment of tissue injuries and recommendations for rehabilitation.

"Our finding that mechanical stresses caused by movement can disrupt the initial formation and growth of new blood vessels supports the advice doctors have been giving their patients for years to limit activity early in the healing process," said Robert Guldberg, a professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. "However, our findings also suggest applying mechanical stresses to the wound later on can significantly improve healing through a process called adaptive remodeling."

The study was published last month in the journal Proceedings of the National Academy of Sciences. The research was supported by the National Institutes of Health, the Armed Forces Institute of Regenerative Medicine and the U.S. Department of Defense.

Because blood vessel growth is required for the regeneration of many different tissues, including bone, Guldberg and former Georgia Tech graduate student Joel Boerckel used healing of a bone defect in rats for their study. Following removal of eight millimeters of femur bone, they treated the gap with a polymer scaffold seeded with a growth factor called recombinant human bone morphogenetic protein-2 (rhBMP-2), a potent inducer of bone regeneration. The scaffold was designed in collaboration with Nathaniel Huebsch and David Mooney from Harvard University.

In one group of animals, plates screwed onto the bones to maintain limb stability prevented mechanical forces from being applied to the affected bone. In another group, plates allowed compressive loads along the bone axis to be transferred, but prevented twisting and bending of the limbs. The researchers used contrast-enhanced micro-computed tomography imaging and histology to quantify new bone and blood vessel formation.

The experiments showed that exerting mechanical forces on the injury site immediately after healing began significantly inhibited vascular growth into the bone defect region. The volume of blood vessels and their connectivity were reduced by 66 and 91 percent, respectively, compared to the group for which no force was applied. The lack of vascular growth into the defect produced a 75 percent reduction in bone formation and failure to heal the defect.

But the study found that the same mechanical force that hindered repair early in the healing process became helpful later on.

When the injury site experienced no mechanical force until four weeks after the injury, blood vessels grew into the defect and vascular remodeling began. With delayed loading, the researchers observed a reduction in quantity and connectivity of blood vessels, but the average vessel thickness increased. In addition, bone formation improved by 20 percent compared to when no force was applied, and strong tissue biomaterial integration was evident.

"We found that having a very stable environment initially is very important because mechanical stresses applied early on disrupted very small vessels that were forming," said Guldberg, who is also the director of the Petit Institute for Bioengineering and Bioscience at Georgia Tech. "If you wait until those vessels have grown in and they're a little more mature, applying a mechanical stimulus then induces remodeling so that you end up with a more robust vascular network."

The study's results may help researchers optimize the mechanical properties of tissue regeneration scaffolds in the future.

"Our study shows that one might want to implant a material that is stiff at the very beginning to stabilize the injury site but becomes more compliant with time, to improve vascularization and tissue regeneration," added Guldberg.

Georgia Tech mechanical engineering graduate student Brent Uhrig and postdoctoral fellow Nick Willett also contributed to this research.

Gallium Nitride Is Non-Toxic, Biocompatible; Holds Promise for Implants, Research Finds

ScienceDaily (Oct. 24, 2011) — Researchers from North Carolina State University and Purdue University have shown that the semiconductor material gallium nitride (GaN) is non-toxic and is compatible with human cells -- opening the door to the material's use in a variety of biomedical implant technologies.

Scanning electron microscope image of cell growth on GaN that has been coated with peptides.

GaN is currently used in a host of technologies, from LED lighting to optic sensors, but it is not in widespread use in biomedical implants. However, the new findings from NC State and Purdue mean that GaN holds promise for an array of implantable technologies -- from electrodes used in neurostimulation therapies for Alzheimer's to transistors used to monitor blood chemistry.

"The first finding is that GaN, unlike other semiconductor materials that have been considered for biomedical implants, is not toxic. That minimizes risk to both the environment and to patients," says Dr. Albena Ivanisevic, who co-authored a paper describing the research. Ivanisevic is an associate professor of materials science and engineering at NC State and associate professor of the joint biomedical engineering program at NC State and the University of North Carolina at Chapel Hill.

Researchers used a mass spectrometry technique to see how much gallium is released from GaN when the material is exposed to various environments that mimic conditions in the human body. This is important because gallium oxides are toxic. But the researchers found that GaN is very stable in these environments -- releasing such a tiny amount of gallium that it is non-toxic.

The researchers also wanted to determine GaN's potential biocompatibility. To do this they bonded peptides -- the building blocks that make up proteins -- to the GaN material. Researchers then placed peptide-coated GaN and uncoated GaN into cell cultures to see how the material and the cells interacted.

Researchers found that the peptide-coated GaN bonded more effectively with the cells. Specifically, more cells bonded to the material and those cells spread over a larger area.

"This matters because we want materials that give us some control over cell behavior," Ivanisevic says. "For example, being able to make cells adhere to a material or to avoid it.

"One problem facing many biomedical implants, such as sensors, is that they can become coated with biological material in the body. We've shown that we can coat GaN with peptides that attract and bond with cells. That suggests that we may also be able to coat GaN with peptides that would help prevent cell growth -- and keep the implant 'clean.' Our next step will be to explore the use of such 'anti-fouling' peptides with GaN."

The paper, "Gallium Nitride is Biocompatible and Non-Toxic Before and After Functionalization with Peptides," is forthcoming from Acta Biomaterialia and was co-authored by Ph.D. students Scott A. Jewett and Matthew S. Makowski; undergraduate Benjamin Andrews; and Michael J. Manfra -- all of Purdue. The research was funded by the National Science Foundation.

NC State's Department of Materials Science and Engineering, and joint Department of Biomedical Engineering, are part of the university's College of Engineering.