O Mundo do Biomédico

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 surge...

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 Epidem...

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...

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...

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 – researcher...

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 robót...

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...

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; xylito...

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 he...

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 d...

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.  "...

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 e...

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...