Researchers Find Key to Making Neurons From Stem Cells

A research team at UC San Francisco has discovered an RNA molecule called Pnky that can be manipulated to increase the production of neurons from neural stem cells.

The research, led by neurosurgeon Daniel A. Lim, MD, PhD, and published on March 19, 2015 in Cell Stem Cell, has possible applications in regenerative medicine, including treatments of such disorders as Alzheimer’s disease, Parkinson’s disease and traumatic brain injury, and in cancer treatment.

Co-first authors Alex Ramos, PhD, and Rebecca Andersen, who are students in Lim’s laboratory, first studied Pnky in neural stem cells found in mouse brains, and also identified the molecule in neural stem cells of the developing human brain. They found that when Pnky was removed from stem cells in a process called knockdown, neuron production increased three to four times.

“It is remarkable that when you take Pnky away, the stem cells produce many more neurons,” said Lim, an assistant professor of neurological surgery and director of restorative surgery at UCSF. 

“These findings suggest that Pnky, and perhaps lncRNAs in general, could eventually have important applications in regenerative medicine and cancer treatment.”

Lim observed that Pnky has an intriguing possible connection with brain tumors.

Pnky is one of a number of newly discovered long noncoding RNAs (lncRNAs), which are stretches of 200 or more nucleotides in the human genome that do not code for proteins, yet seem to have a biological function.

The name, pronounced “Pinky,” was inspired by the popular American cartoon series Pinky and the Brain. “Pnky is encoded near a gene called ‘Brain,’ so it sort of suggested itself to the students in my laboratory,” said Lim. Pnky also appears only to be found in the brain, he noted.

Using an analytical technique called mass spectrometry, Ramos found that Pnky binds the protein PTBP1, which is also found in brain tumors and is known to be a driver of brain tumor growth. In neural stem cells, Pnky and PTBP1 appear to function together to suppress the production of neurons. “Take away one or the other and the stem cells differentiate, making more neurons,” said Lim. “It is also possible that Pnky can regulate brain tumor growth, which means we may have identified a target for the treatment of brain tumors.”

Lim said that the larger significance of the research is that it adds to a growing store of knowledge about lncRNAs, previously unknown sections of the genome that some biologists have referred to as the “dark matter” of the human genome.

“Recently, over fifty thousand human lncRNAs have been discovered. Thus, there may be more human lncRNAs than there are genes that code for proteins,” said Lim. “It is possible that not all lncRNAs have important biological functions, but we are making a start toward learning which ones do, and if so, how they function. It’s a new world of experimental biology, and the students in my lab are right there on the frontier.”

Lim had particular praise for Ramos, an MD-PhD student in the UCSF Medical Scientist Training Program, and Andersen, who has a fellowship from the prestigious National Science Foundation (NSF) Graduate Research Fellowship Program. “They have been a great collaborative team and an inspiration to others in my lab,” said Lim. “I think they represent the pioneering, investigative spirit of the UCSF student body.”

Fonte: http://bioengineer.org/researchers-find-key-to-making-neurons-from-stem-cells/

How our DNA may prevent bowel cancer

A new study published in the prestigious Journal of the American Medical Association (JAMA) suggests the link between aspirin and colon cancer prevention may depend on a person’s individual genetics.

The link between taking aspirin, and similar medications called non-steroidal anti-inflammatory drugs (or NSAIDS), and bowel (colorectal) cancer prevention is well established.

However, the mechanisms behind the protective effect have not been understood and it is not known why some people appear to benefit while others do not.

Conducted by investigators from four countries, including Professors Mark Jenkins and John Hopper from the University of Melbourne, the findings suggest this protection differs according to variations in DNA.

“We’ve known for a long time that aspirin lowers the risk of bowel cancer, but we also know that not everyone gets the same degree of protection,” said Professor Mark Jenkins, a co-author of the paper and Director of the Centre for Epidemiology and Biostatistics, School of Population and Global Health.

“The aim of this study was to investigate if genetic variation can be used to determine who will benefit from taking aspirin and who will not,” he said.

For the study, Professors Jenkins, Hopper and collaborators analysed the combined data from ten large studies conducted in Australia, USA, Canada and Germany.

They compared genetic and lifestyle data from 8,624 people who developed bowel cancer with that of 8,553 people who did not.

An important component of this data included 1,085 participants from Australia who enrolled in the Australasian Colorectal Cancer Family Study.

“This study confirmed that for most people, taking regular aspirin and NSAIDs lowered their risk of bowel cancer, but it also showed that the benefit from taking these medicines was not the same for everyone, and one of the differences was in their DNA” said Professor Jenkins.

“While most people benefit from aspirin, there was DNA evidence that about 1 in 25 people do not, and in fact may increase their risk of bowel cancer if they take aspirin,” Professor Jenkins said.

“While these results are very promising, they do need to be validated in independent studies before they can be used to determine who should and should not take aspirin to prevent bowel cancer,” cautioned Professor Jenkins.

Fonte: http://bioengineer.org/how-our-dna-may-prevent-bowel-cancer/

Early Diagnosis Opportunities for Alzheimer’s Through Simple Blood Test

By the time most people receive a diagnosis of Alzheimer’s disease — based on clinical signs of mental decline — their brains have already suffered a decade or more of damage. But although the mechanisms that spur the destruction of neurons in Alzheimer’s disease are not yet fully understood, two well-documented signs of the condition are accumulation of the amyloid-β peptide (the main component of plaques found in Alzheimer’s patient brains) and chronic inflammation.

New research from Rockefeller University, published March 16 in the Proceedings of the National Academy of Sciences, identifies a bridge between the two. That bridge, a molecular cascade known as the contact system, may provide opportunities for early diagnosis of the disease through simple blood tests.

“People have been looking for a long time for markers for Alzheimer’s disease,” says Sidney Strickland, head of the Patricia and John Rosenwald Laboratory of Neurobiology and Genetics. But current diagnostic tests for pre-symptomatic Alzheimer’s leave much to be desired. Evaluating the level of amyloid-β in the cerebral spinal fluid, for instance, requires an invasive spinal tap procedure.

“Finding a blood biomarker that would let us know through a simple test whether someone is on their way to developing the disease would be a significant advance,” says first author Daria Zamolodchikov, a postdoctoral associate in the Strickland lab.

The new study grew from the lab’s ongoing work that looks at how the vascular system is involved in Alzheimer’s disease. It has been shown that amyloid-β can activate a protein in plasma called factor XII, the first step in a pathway known as the contact system. When activated, this system leads to the release of a small peptide called bradykinin, a molecule known to promote potentially damaging inflammation. Although some studies have found these molecules in the cerebral spinal fluid and brain tissue of Alzheimer’s patients, no one had studied them in Alzheimer’s patient plasma.

Using plasma from people with and without diagnosed Alzheimer’s disease, the researchers measured the activation levels of the contact system. They found increased activation of this system in the plasma of Alzheimer’s patients, potentially implicating it in the inflammatory pathology of the disease. Moreover, in a subset of patients whose amyloid-β levels in the cerebral spinal fluid were known, the researchers demonstrated a positive correlation between activation of the contact system and changes in cerebral spinal fluid amyloid-β levels, which as mentioned above are correlated with the development of Alzheimer’s.

The researchers found similar activation of the contact system in mouse models of Alzheimer’s, which are genetically modified to overproduce amyloid-β. They then conducted a follow-up experiment with healthy mice. “We went one step further and took completely normal wild-type mice and injected them with amyloid-β. We found that on its own, injection with amyloid-β can activate this system. It’s a proof of principle in a complex environment,” says Zamolodchikov.

These findings will need to be supported by studies in larger patient populations and longitudinal studies, but they could eventually open the door to diagnosis of pre-symptomatic Alzheimer’s based on blood levels of these molecules.

The contact system may also offer a new approach to therapies for Alzheimer’s disease, since inhibition of the pathway could blunt some of the inflammatory aspects of the disease. One concern is that the contact system is also involved in blood clotting and inhibition might carry a risk of bleeding. However, people with a defect in this system do not have hemophilia. Thus, inhibition of this pathway might slow progression of the disease without increasing the risk of hemorrhage.

Fonte: http://bioengineer.org/early-diagnosis-opportunities-for-alzheimers-through-simple-blood-test/

Scientists call for caution in using DNA-editing technology

A group of 18 scientists and ethicists today warned that a revolutionary new tool to cut and splice DNA should be used cautiously when attempting to fix human genetic disease, and strongly discouraged any attempts at making changes to the human genome that could be passed on to offspring.

Among the authors of this warning is Jennifer Doudna, the co-inventor of the technology, called CRISPR-Cas9, which is driving a new interest in gene therapy, or “genome engineering.” She and colleagues co-authored a perspective piece that appears in the March 20 issue of Science, based on discussions at a meeting that took place in Napa on Jan. 24. The same issue of Science features a collection of recent research papers, commentary and news articles on CRISPR and its implications.

“Given the speed with which the genome engineering field is evolving, our group concluded that there is an urgent need for open discussion of the merits and risks of human genome modification by a broad cohort of scientists, clinicians, social scientists, the general public and relevant public entities and interest groups,” the authors wrote.

Doudna, director of UC Berkeley’s Innovative Genomics Initiative, was joined by five current and two former UC Berkeley scientists, plus David Baltimore, a Nobel laureate and president emeritus of the California Institute of Technology, Stanford Nobelist Paul Berg and eminent scientists from UC San Francisco, Stanford, Harvard and the universities of Wisconsin and Utah. Several of these scientists are currently involved in gene therapy to cure inherited diseases.

Such warnings have been issued numerous times since the dawn of genetic engineering in 1975, but until now the technology to actually fix genetic defects was hard to use.

“However, this limitation has been upended recently by the rapid development and widespread adoption of a simple, inexpensive and remarkably effective genome engineering method known as CRISPR-Cas9,” the scientists wrote. “The simplicity of the CRISPR-Cas9 system enables any researcher with knowledge of molecular biology to modify genomes, making feasible many experiments that were previously difficult or impossible to conduct.”

Correcting genetic defects

Scientists today are changing DNA sequences to correct genetic defects in animals as well as cultured tissues generated from stem cells, strategies that could eventually be used to treat human disease. The technology can also be used to engineer animals with genetic diseases mimicking human disease, which could lead to new insights into previously enigmatic disorders.

The CRISPR-Cas9 tool is still being refined to ensure that genetic changes are precisely targeted, Doudna said. Nevertheless, the authors met “… to initiate an informed discussion of the uses of genome engineering technology, and to identify proactively those areas where current action is essential to prepare for future developments. We recommend taking immediate steps toward ensuring that the application of genome engineering technology is performed safely and ethically.”

Of particular concern are changes to genes in “germline cells” – sperm and egg – that can be passed on to offspring. Even a germline modification that eliminated a genetic disease that has plagued a family for generations could have unintended consequences, given current limitations on our knowledge of human genetics.

“We believe that initiating these fascinating and challenging discussions now will optimize the decisions society will make at the advent of a new era in biology and genetics,” the authors concluded.

The UC Berkeley authors are Michael Botchan, a professor of molecular and cell biology and IGI co-director; G. Steven Martin, dean of biological sciences and a professor of molecular and cell biology; chemistry researcher Samuel Sternberg; IGI scientific director Jacob Corn; and IGI program director Marsha Fenner. Edward Penhoet, a former dean of the UC Berkeley School of Public Health, and Martin Jinek, a co-inventor of CRISPR now at the University of Zurich, also signed the commentary.

Doudna is also the Li Ka Shing Chancellor’s Chair in Biomedical and Health Sciences and a Howard Hughes Medical Institute investigator at UC Berkeley.

Fonte:http://bioengineer.org/scientists-call-for-caution-in-using-dna-editing-technology/

World-first cancer drugs could work in larger group of patients

A pioneering class of drugs that target cancers with mutations in the BRCA breast cancer genes could also work against tumours with another type of genetic fault, a new study suggests.

Scientists at The Institute of Cancer Research, London, found that errors in a gene called CBLC leave cancer cells vulnerable to PARP inhibitor drugs. Around 2 per cent of all tumours have defects in CBLC.

The study, which was carried out in collaboration with colleagues in Denmark and the Czech Republic, was funded in the UK by the European Union, and was published today in the journal Oncotarget.

Olaparib, a PARP inhibitor, became the first cancer drug targeted at an inherited genetic fault to reach the market when it was approved in December for use in ovarian cancer patients with BRCA1 or BRCA2 mutations. Its development was underpinned by research at the ICR.

Using an approach known as RNA interference screening – which ‘silences’ genes to analyse their function – researchers systematically tested which of the 25,000 genes in the human genome affected the response of cancer cells to olaparib.

The ICR team found that cancer cells with a defect in the CBLC gene were as sensitive to the drug as those with a faulty BRCA2 gene.

By analysing the molecular processes that the CBLC gene controls, researchers found that it normally allows cells to repair damaged DNA by fixing broken DNA strands back together.

This finding indicates that a flaw in DNA repair mechanisms explains the sensitivity of CBLC-defective cancer cells to PARP inhibitors – which knock out the action of another DNA repair mechanism.

DNA repair is often disrupted in cancer cells, which sacrifice genetic stability as they gain mutations that allow them to divide uncontrollably. These cancer cells may be particularly vulnerable to drugs to block DNA repair proteins, since they may lack any alternative functioning repair systems to fall back on.

Study co-leader Dr Chris Lord, Team Leader in Gene Function at the ICR, said: “Our study has found that defects in a rather poorly studied DNA repair gene called CBLC seem to greatly increase sensitivity to olaparib, a PARP inhibitor which is currently licensed only for BRCA-mutated cancer.

“PARP inhibitors are an exciting new class of cancer drug. Understanding why different types of tumour cells respond to PARP inhibitors will play a critical part in making sure these new drugs are used in the most effective way.”

Professor Paul Workman, Chief Executive of the ICR, said: “The development of PARP inhibitors is a UK success story, with collaboration between ICR academics, companies, charities and the NHS leading to trials in BRCA-mutated cancers and the licensing of olaparib only a few months ago.

“This new study adds to evidence that PARP inhibitors can be effective in a broader group of patients than those with BRCA mutations, and could lead to them being used more widely in patients with other kinds of faults in DNA repair.”

Fonte:http://bioengineer.org/world-first-cancer-drugs-could-work-in-larger-group-of-patients/#prettyPhoto

Luva devolve movimentos das mãos a pacientes que tiveram AVC

Musical Glove é um dispositivo de computação em formato de luva que promete ser um grande aliado na reabilitação de pessoas que sofreram um AVC, pois ajuda a melhorar suas habilidades motoras finas. A luva é equipada com minúsculos sensores que são capazes de controlar os movimentos das mãos do usuário, permitindo com que ele jogue jogos apertando e segurando teclas na tela de uma tablet.

Segundo Nizan Firedman, fundador da Flint Dispositivos para Reabilitação, são esses alguns dos exercícios recomendados para serem executados pelos pacientes depois de deixar o hospital, pois são de alta repetição. A ideia da luva musical é manter as pessoas mais motivadas a fazerem os exercícios, sem ficarem entediados.

Friedman teve a ideia de criar o dispositivo enquanto fazia doutorado em engenharia biomédica na Universidade da Califórnia, com David Reinkesmeyer e Mark Bachman. Inicialmente, queriam juntar robótica e musicoterapia, mas, por causa dos elevados custos da robótica, surgiu a ideia da luva, que se saiu melhor do que eles imaginavam. “As pessoas que não tinham usado as mãos em meses ou até mesmo anos, estavam vendo benefício”, lembra Friedman.

Além das vendas para clínicas de reabilitação de pacientes, uma versão doméstica da novidade também é vendida em um kit com, além da própria luva, um tablet projetado especialmente para ela. 

Fonte:http://www.techtudo.com.br/noticias/noticia/2015/03/luva-devolve-movimentos-das-maos-a-pacientes-que-tiveram-avc-entenda.html

New Compound Prevents Diabetes Before It Begins

Scientists from the Florida campus of The Scripps Research Institute (TSRI) have successfully tested a potent synthetic compound that prevents type 1 diabetes in animal models of the disease.

“The animals in our study never developed high blood sugar indicative of diabetes, and beta cell damage was significantly reduced compared to animals that hadn’t been treated with our compound,” said Laura Solt, Ph.D., a TSRI biologist who was the lead author of the study.

Type 1 diabetes is a consequence of the autoimmune destruction of insulin-producing beta cells in the pancreas. While standard treatment for the disease aims to replace lost insulin, the new study focuses instead on the possibility of preventing the initial devastation caused by the immune system—stopping the disease before it even gets started.

In the study, published in the March 2015 issue of the journal Endocrinology, the scientists tested an experimental compound known as SR1001 in non-obese diabetic animal models. The compound targets a pair of “nuclear receptors” (RORα and RORg) that play critical roles in the development of a specific population (Th17) of immune cells associated with the disease.

“Because Th17 cells have been linked to a number of autoimmune diseases, including multiple sclerosis, we thought our compound might inhibit Th17 cells in type 1 diabetes and possibly interfere with disease progression,” said Solt. “We were right.”

The researchers found SR1001 eliminated the incidence of diabetes and minimized insulitis, which is the inflammation associated with, and destroyer of, insulin-producing cells, in the treated animals. The compound suppressed the immune response, including the production of Th17 cells, while maintaining normal insulin levels; it also increased the frequency of the expression of Foxp3 in T cells, which controls the development and function of a type of immune cell known as T regulatory cells.

Solt notes that the study strongly suggests that Th17 cells have a pathological role in the development of type 1 diabetes and use of ROR-specific synthetic compounds targeting this cell type may have potential as a preventative therapy for type 1 diabetes. “It certainly opens the door for other areas to be looked at,” she said.

Fonte: http://bioengineer.org/new-compound-prevents-diabetes-before-it-begins/

Draw Biosensors on Your Skin

Someday soon, on-demand diagnostics could be as simple as doodling on your arm or leg. Special sensor-laden inks would help diabetics monitor their blood sugar and allow people to stay on top of other elements of their body chemistry. The write-once, read-several-times inks could also let homeowners test for toxic pollutants, and help soldiers detect explosives and nerve agents on the battlefield.

Researchers at the University of California, San Diego (UCSD) who developed the inks published their results in the 26 February issue of the journal Advanced Healthcare Materials. They revealed that the main ingredients of these inks are the enzymes glucose oxidase, which responds to blood glucose, and tyrosinase, which responds to common pollutants known as phenols. To make these bio-inks serve as electrodes, they added electrically conductive graphite powder. They also added: chitosan, a clotting agent used in bandages, to help the ink stick to surfaces; xylitol, a sugar substitute, to help stabilize the enzymes during chemical reactions; and biocompatible polyethylene glycol, which is used in several drug delivery applications, to help bind all these ingredients together.

The scientists filled off-the-shelf ballpoint pens with their enzymatic inks. The pens could create a blood glucose sensor simply by drawing glucose-sensitive ink on a transparent, flexible strip that included an electrode. When a blood drop was placed on the sensor, the ink reacted with glucose in the blood and the sensor measured the reaction.

The UCSD team demonstrated that these biosensors were reusable. They only had to wipe the strips clean and draw more ink on them.

But the eye-popping achievement they reported was that the inks coul deliminate painful finger pricks to draw blood simply by scrawling sensors directly on the body. The diagnostic body art, they said in the paper detailing their findings, would take glucose readings through the skin and deliver the results via a Bluetooth device. The investigators estimated one pen held enough ink to write the equivalent of roughly 500 blood glucose sensor strips.

The pens could also draw sensors on leaves to detect pollution using phenol-sensitive ink. The scientists noted that the inks could be modified to react with many other pollutants, such as heavy metals or pesticides, and can be drawn on a variety of surfaces such as smartphone cases and building windows.

The UCSD researchers noted these pens could help people build useful sensors anywhere easily and cheaply anytime they need to, without needing to know ahead of time where and when sensors might be required. The group’s next steps include connecting the handwritten sensors wirelessly to monitoring devices and analyzing how they perform in difficult conditions such as extreme temperatures, varying humidity levels, and extended exposure to sunlight.

Fonte: http://spectrum.ieee.org/tech-talk/biomedical/devices/draw-biosensors-on-your-skin

A Brain-Computer Interface That Lasts for Weeks

Brain signals can be read using soft, flexible, wearable electrodes that stick onto and near the ear like a temporary tattoo and can stay on for more than two weeks even during highly demanding activities such as exercise and swimming, researchers say.

The invention could be used for a persistent brain-computer interface (BCI) to help people operate prosthetics, computers, and other machines using only their minds, scientists add.

For more than 80 years, scientists have analyzed human brain activity non-invasively by recording electroencephalograms (EEGs). Conventionally, this involves electrodes stuck onto the head with conductive gel. The electrodes typically cannot stay mounted to the skin for more than a few days, which limits widespread use of EEGs for applications such as BCIs.

Now materials scientist John Rogers at the University of Illinois at Urbana-Champaign and his colleagues have developed a wearable device that can help record EEGs uninterrupted for more than 14 days. Moreover, their invention survived despite showering, bathing, and sleeping. And it did so without irritating the skin. The two weeks might be "a rough upper limit, defined by the timescale for natural exfoliation of skin cells," Rogers says. 

The device consists of a soft, foldable collection of gold electrodes only 300 nanometers thick and 30 micrometers wide mounted on a soft plastic film. This assemblage stays stuck to the body using electric forces known as van der Waals interactions—the same forces that help geckoes cling cling to walls.

The electrodes are flexible enough to mold onto the ear and the mastoid process behind the ear. The researchers mounted the device onto three volunteers using tweezers. Spray-on bandage was used once twice a day to help the electrodes survive normal daily activities.

The electrodes on the mastoid process recorded brain activity while those on the ear were used as a ground wire. The electrodes were connected to a stretchable wire that could plug into monitoring devices. "Most of the experiments used devices mounted on just one side, but dual sides is certainly possible," Rogers says.

The device helped record brain signals well enough for the volunteers to operate a text-speller by thought, albeit at a slow rate of 2.3 to 2.5 letters per minute.

According to Rogers, this research: 

...could enable a persistent BCI that one could imagine might help disabled people, for whom mind control is an attractive option for operating prosthetics… It could also be useful for monitoring cognitive states—for instance, to see if people are paying attention while they're driving a truck, flying an airplane, or operating complex machinery. It could also help monitor patterns of sleep to better understand sleep disorders such as sleep apnea, or for monitoring brain function during learning.

The scientists hope to improve the speed at which people can use this device to communicate mentally, which could expand its use into commercial wearable electronics. They also plan to explore devices that can operate wirelessly, Rogers says. The researchers detailed their findings online March 16 in the journal Proceedings of the National Academy of Sciences.

Fonte: http://spectrum.ieee.org/tech-talk/biomedical/bionics/a-braincomputing-interface-that-lasts-for-weeks

Platina pode ser eficaz contra o cancro do pâncreas

Um grupo internacional de investigadores conseguiu, pela primeira vez, descobrir quais os quatro subtipos em se divide o cancro do pâncreas, tendo anunciado que, consoante o subtipo da doença, o uso de medicamentos com platina pode ser benéfico para o tratamento dos pacientes.

Segundo os cientistas, coordenados por Andrew Biankin, da organização britânica Cancer Research UK, estes subtipos distinguem-se entre si através das caraterísticas do ADN - estável, instável, reorganizado localmente ou disperso - e desenvolvem-se, todos eles, devido a uma "confusão genética" resultante de danos causados em genes específicos.

Isto significa, portanto, que os tumores pancreáticos podem, de futuro, ser classificados não apenas de acordo com a frequência ou a localização, mas com base nas "reorganizações" de ADN provocadas pelas falhas genéticas, falhas que, sabe-se agora, podem ser potencialmente combatidas com medicamentos já existentes.

"Apesar das muitas décadas de investigação sobre o cancro pancréatico, temos enfrentado numerosos obstáculos na procura por tratamentos novos e eficientes", admite, em comunicado, o líder deste estudo internacional, Andrew Biankin.

"Porém, o nosso trabalho, que explica de que forma a reorganização caótica dos cromossomas desencadeia danos nos genes que, por sua vez, levam à doença, traz consigo a oportunidade de criar tratamentos mais personalizados contra este problema", congratula-se o investigador.

A equipa descobriu ainda que o uso de medicamentos com platina - commumente utilizados em tratamentos de quimioterapia contra o cancro do ovário ou do testículo - pode, além disso, beneficiar os pacientes cujo cancro pancreático se insira no subtipo da doença resultante da reorganização instável do ADN.

Até ao momento, estes fármacos têm tipo um impacto limitado contra o cancro do pâncreas, mas, no âmbito deste estudo, publicado, recentemente, na revista científica Nature, os especialistas tomaram conhecimento de que um número reduzido de pacientes mostrou "melhorias excecionais" graças à sua administração.

 "Embora a maior parte dos pacientes não responda à terapia com platina, certo número beneficiou de uma resposta impressionante, que a maioria dos oncologistas nunca esperou ver durante toda a vida", revela Biankin.

O cientista adianta que "duas pessoas tratadas com platina viram os seus tumores desaparecer completamente e uma delas está viva cinco anos depois do diagnóstico", uma esperança renovada para os doentes já que, em ambos os casos, os cancros estavam em estágios tão avançados que a esperança de vida era de apenas alguns meses. 

"Conseguir identificar os pacientes que podem beneficiar dos fármacos baseados na platina será uma viragem determinante para tratar o cancro pancreático, aumentando, potencialmente, a sobrevivência de uma parcela dos doentes", finaliza o investigador, que acrescenta que tal poderá permitir também o desenvolvimento de medicamentos mais eficientes.

Fonte: http://boasnoticias.pt/noticias_Platina-pode-ser-eficaz-contra-o-cancro-do-p%C3%A2ncreas_22606.html?page=0

Artigo : http://www.nature.com/nature/journal/v518/n7540/full/nature14169.html

Sementes de abóbora são o melhor "snack" para o humor

Quando se sentir em baixo, esqueça os bolos e os chocolates. Embora os doces sejam, com frequência, os "snacks" preferidos de homens e mulheres contra a tristeza, especialistas britânicas asseguram que as sementes, em especial as de abóbora e chia, são os aperitivos ideais para melhorar o humor. 

Um inquérito realizado pela marca inglesa de arroz Tilda envolvendo 2.000 pessoas revelou que sete em cada 10 mulheres e um em cada dois homens se "presenteiam" com um doce quando estão nervosos ou precisam de uma injeção de ânimo, sendo que apenas uma em cada sete pessoas afirma preferir fruta, vegetais ou grãos, alimentos que combatem o 'stress' e promovem o bem-estar mental.

De acordo com a dietista Sarah Schenker e a psicóloga alimentar Christy Fergusson, que trabalham com a marca, optar pelas alternativas mais calóricas e ricas em açúcar é uma má ideia e contribui mesmo, a longo-prazo, para intensificar a sensação de infelicidade. 

"É chocante observar que os hábitos alimentares saudáveis são 'atirados pela janela' quando as pessoas se confrontam com um desafio ou um aborrecimento na rotina", afirma Schenker, citada pelo jornal Daily Mail. 

Segundo a especialista, é nestes momentos que "a alimentação saudável é mais importante". "Precisamos de substituir a adrenalina de pouca dura que obtemos a partir do açúcar refinado e as gorduras processadas por opções saudáveis e hábitos alimentares saudáveis de longo-prazo", alerta a britânica. 

Schenker e Fergusson compilaram, a propósito do inquérito realizado, uma lista com os 10 melhores alimentos para beneficiar o humor. Além das sementes de abóbora e chia, que lideram o 'top', fazem também parte das escolhas ideias o salmão, o arroz, a quinoa, o grão de bico, o côco, os espargos, os espinafres e o feijão. 

"Para nos sentirmos melhor e produzirmos químicos 'felizes' precisamos de fornecer ao nosso organismo as pedras basilares corretas", destaca Fergusson.

 "Estas 'pedras basilares' apresentam-se sob a forma de aminoácidos que são necessários para a produção de hormonas, incluindo a serotonina, um dos mais importantes químicos cerebrais ao nível do humor e da regulação do sono", acrescenta a psicóloga, justificando, assim, a importância de manter uma alimentação saudável mesmo em períodos de desgaste emocional.

Fonte: http://boasnoticias.pt/noticias_Sementes-de-ab%C3%B3bora-s%C3%A3o-o-melhor-snack-para-o-humor_22615.html?page=0

Livro : http://www.tilda.com/wholegrain

Fazer voluntariado alivia o 'stress' e o cansaço

Ajudar os outros ajuda-nos, também, a nós próprios. A conclusão é de um novo estudo internacional que revela que fazer voluntariado contribui para reduzir o 'stress' e a exaustão associados ao trabalho, aumentando o equilíbrio entre a vida pessoal e profissional.

A investigação publicada este mês na revista científica Journal of Occupational and Environmental Medicine, debruçou-se sobre 746 trabalhadores suíços que exercem funções a tempo inteiro e a tempo parcial, 35% dos quais se dedicam, também, ao voluntariado, várias vezes por ano.

 Através de inquéritos, os cientistas procuraram "compreender a relação entre o voluntariado e a saúde" com vista a apurar se esta prática pode funcionar como "um recurso psicossocial, contribuindo para um maior balanço entre a vida pessoal e profissional e, em última instância, para uma melhor saúde". 

 Os participantes no estudo responderam a questões sobre a exigência do emprego e a sua perceção acerca do equilíbrio entre vida e trabalho. Além disso, a equipa de investigadores procurou, também, medir os seus níveis de 'stress' cansaço associados à atividade profissional. 

 O estudo provou que os que indivíduos que praticavam voluntariado apresentavam níveis inferiores de 'stress' e tinham menor probabilidade de se sentir exaustos no trabalho.

Os voluntários relataram, também, uma maior sensação de equilíbrio entre vida profissional e pessoal em comparação com os que não tinham por hábito fazer voluntariado.

 "Embora consuma energia e tempo, o voluntariado pode contribuir para uma maior sensação de equilíbrio entre os trabalhadores, o que, por sua vez, pode influenciar positivamente a saúde", afirmam os autores da investigação.

Esta não é a primeira vez que os benefícios do voluntariado para a saúde são comprovados pela ciência. Em 2013, a Universidade de Harvard revelou que ser voluntário faz bem ao corpo e à mente e contribui, até, para baixar a tensão arterial, para aumentar a longevidade e para diminuir os sentimentos de solidão e depressão. 

Fonte: http://boasnoticias.pt/noticias_Fazer-voluntariado-alivia-o-stress-e-o-cansa%C3%A7o_22620.html?page=0

Artigo: http://www.ncbi.nlm.nih.gov/pubmed/25654517

Afinal, beber café pode reduzir risco de ataque cardíaco

A relação entre o consumo de café e a saúde cardiovascular é, por norma, amplamente debatida, com a bebida a ser, muitas vezes, associada à hipertensão arterial. Agora, um novo estudo revelou, porém, que o café pode ajudar a diminuir o risco de ataque cardíaco ao contribuir para evitar o entupimento das artérias. 

Um grupo de investigadores do Kangbuk Samgun Hospital, em Seul, na Coreia do Sul, realizou uma meta-análise de um total de 36 estudos que se debruçaram sobre a associação entre o consumo de café e o risco de doença cardiovascular, tendo constatado que a ingestão de três a cinco chavénas de café diárias parece contribuir para uma menor probabilidade de ataque cardíaco. 

 Para chegar a estas conclusões, os cientistas examinaram a relação entre a ingestão de café e a acumulação de cálcio nas artérias coronárias, um indicador precoce da aterosclerose, doença que se carateriza pelo entupimento das artérias com placas de gordura, que, em consequência, se estreitam e "enrijecem", conduzindo ao aparecimento de coágulos e aumentando o risco de ataque cardíaco e enfarte. 

 A equipa avaliou dados sobre um total de 25.138 homens e mulheres com uma média de idades de 41 anos e sem quaisquer sinais de doença cardiovascular. Tendo em consideração fatores como o nível de atividade física, os hábitos tabágicos, o historial familiar e a alimentação, dividiram, depois, o grupo, de acordo com o consumo de café (que variava de menos uma chávena por dia a cinco ou mais chávenas diárias). 

 De acordo com o estudo, a prevalência média de cálcio detetável nas artérias era de 13,4% em todo o grupo, com um consumo médio de café de 1,8 chávenas por dia. A percentagem mais baixa de entupimento das artérias (0,59%) registou-se entre os que bebiam três a cinco chávenas de café diariamente, revelam os investigadores.

 "O nosso estudo vem juntar-se ao crescente conjunto de evidências que sugere que o consumo de café pode estar inversamente associado ao risco de doença cardiovascular", escrevem os autores a propósito da investigação publicada esta segunda-feira na revista cientifica Heart. 

Ainda assim, realçam, será necessária uma investigação mais aprofundada para "confirmar" os resultados do estudo e para "estabelecer a base biológica do possível efeito preventivo do café contra a doença coronária". 

 Os especialistas apontam como possíveis explicações para os benefícios do café o facto de o consumo da bebida estar associado a uma menor probabilidade de desenvolver diabetes tipo 2, um fator de risco da aterosclerose, e de melhorar a sensibilidade à insulina e o funcionamento das células beta pancreáticas.

Fonte: http://boasnoticias.pt/noticias_Afinal,-beber-caf%C3%A9-pode-reduzir-risco-de-ataque-card%C3%ADaco_22661.html?page=0

Artigo : http://heart.bmj.com/content/early/2015/02/06/heartjnl-2014-306663.abstract?sid=dbb36fdf-6efb-42d5-bf83-e20a23484618