Your dog understands more than you think

It’s the eternal question for pet owners: Does your dog understand what you’re saying?
Even if Fido doesn’t “get” your words, surely he gets your tone when you let loose about
another accident on the carpet. But a new imaging study shows that dogs’ brains respond to actual words, not just the tone in which they’re said. The study will likely shake up research into the origins of language, scientists say, as well as gratify dog lovers.

“It’s an important study that shows that basic aspects of speech perception can be shared with quite distant relatives,” says Tecumseh Fitch, a cognitive biologist at the University of Vienna, who was not involved in the work.

Words, the basic building blocks of human languages, are seldom found among other species. Bottlenose dolphins and green-rumped parrotlets make sounds that function like names, and animals including chickens, prairie dogs, and some primates utter alarm calls that identify specific predators. Dogs don’t produce words, but some are known to recognize more than 1000 human words—behavior that suggests they may attach meaning to human sounds. The new study shows that it is indeed the words themselves—and not the tone in which they're spoken or the context in which they're used—that dogs comprehend.

To find out how dogs process human speech, Attila Andics, a neuroscientist at Eötvös Loránd University in Budapest, and his colleagues used brain scanners and 13 willing family dogs from four breeds: border collies, golden retrievers, Chinese crested dogs, and German shepherds. The dogs had been trained to lie motionless in the scanner while they listened to recordings of their trainer’s voice. The dogs heard meaningful words (“well done!” in Hungarian) in a praising tone and in a neutral tone. They also heard meaningless words (“as if”) in a neutral or praising tone of voice.

When the scientists analyzed the brain scans, they saw that—regardless of the trainer’s intonation—the dogs processed the meaningful words in the left hemisphere of the brain, just as humans do, they write this week in Science. But the dogs didn’t do this for the meaningless words. “There’s no acoustic reason for this difference,” Andics says. “It shows that these words have meaning to dogs.”

The dogs also processed intonation in the right hemisphere of their brains, also like humans. And when they heard words of praise delivered in a praising tone, yet another part of their brain lit up: the reward area. Meaning and tone enhanced each other. “They integrate the two types of information to interpret what they heard, just as we do,” Andics says.

The new results add to scientists’ knowledge of how canine brains process human speech. Dogs have brain areas dedicated to interpreting voices, distinguishing sounds (in the left hemisphere), and analyzing the sounds that convey emotions (in the right hemisphere).

The finding “doesn’t mean that dogs understand everything we say,” says Julie Hecht, who studies canine behavior and cognition at City University of New York in New York City and who was not involved in the study. “But our words and intonations are not meaningless to dogs.” Fitch hopes that similar studies will be done on other domestic animals and on human-raised wolves to see how much of this ability is hardwired in dogs and how much is due to growing up among talking humans.

‘Bad luck’ not a major cause of cancer, new study says

In January, two researchers at Johns Hopkins University in Baltimore, Maryland, (and the journalists who wrote about them) spurred a firestorm by writing in Science that much of cancer is due to “bad luck,” or random mistakes that take place when cells divide. That paper launched a lively debate, and today a group at the State University of New York at Stony Brook has fired back: The authors argue in Nature that the earlier analysis was flawed, and cancers are due to this “bad luck” only 10% to 30% of the time, STAT reports. The Stony Brook researchers say that, instead, external causes such as environmental risks overwhelmingly drive disease.

Publicação retirada da Science.org

Two gene networks help control human intelligence

About 40% of variation in human intelligence is inherited, but isolating the genes responsible has been a daunting task. Now, researchers have leveraged vast amounts of genetic and behavioral data to identify two networks of genes that seem to contribute to higher brain functions, The Guardian reports. The networks are implicated in both neurodevelopmental disorders and normal variation in cognitive abilities, the researchers reported Monday in Nature Neuroscience. Perhaps most exciting, the networks are likely to share the same regulatory system—a system that researchers could potentially target to treat conditions such as epilepsy and schizophrenia. 

Novas descobertas científicas sugerem que os filhos podem herdar mais do que simplesmente genes.
Abaixo a reportagem, na íntegra.

Male mice bequeath an unexpected legacy to their progeny. Two studies published online this week in Science reveal that sperm from the rodents carry pieces of RNAs that alter the metabolism of their offspring. The RNAs spotlighted by the studies normally help synthesize proteins, so the findings point to an unconventional form of inheritance. The results are “exciting and surprising, but not impossible,” says geneticist Joseph Nadeau of the Pacific Northwest Diabetes Research Institute in Seattle, Washington. 

“Impossible” is exactly how biologists once described so-called epigenetic inheritance, in which something other than a DNA sequence passes a trait between generations. In recent years, however, researchers have found many examples. A male mouse’s diet and stress level, for instance, can tweak offspring metabolism. Researchers are still trying to determine how offspring inherit a father’s metabolic attributes and physiological condition. Some evidence implicates chemical modification of DNA. Other work by neuroscientist Tracy Bale of the University of Pennsylvania Perelman School of Medicine in Philadelphia and colleagues has found that mammalian sperm pack gene-regulating molecules called microRNAs.

The new work highlights a different class of RNAs, transfer RNAs (tRNAs). In one study, genomicist Oliver Rando of the University of Massachusetts Medical School in Worcester and colleagues delved into a case of epigenetic inheritance in which the progeny of mice fed a low-protein diet show elevated activity of genes involved in cholesterol and lipid metabolism. When Rando’s group analyzed sperm from the protein-deprived males, they uncovered an increased abundance of fragments from several kinds of tRNAs. The researchers concluded the sperm acquired most of these fragments while passing through the epididymis, a duct from the testicle where the cells mature. 

In the second study, a team from the Chinese Academy of Sciences in Beijing and other institutions also homed in on tRNA fragments. After feeding male mice either a high-fat or low-fat diet, the scientists injected the animals’ sperm into unfertilized eggs. They then tracked the metabolic performance of the offspring, which ate a normal diet. Although progeny of the fat-eating fathers remained lean, they showed two abnormalities often found in their dads and in people who are obese or diabetic: abnormal absorption of glucose and insensitivity to insulin. To determine whether tRNA fragments were responsible for the traits, the researchers inserted the fragments into eggs fertilized with other sperm. Fragments that came from fathers that ate the high-fat diet resulted in offspring that also showed impaired glucose absorption. “We’ve found another link that can connect the father and offspring,” says reproductive biologist Qi Chen, a study co-author, now at the University of Nevada School of Medicine in Reno.

Although tRNAs are best known for roles in protein synthesis, their fragments are turning up in other cellular situations. “Pieces of functional units that are pretty well understood can have interesting moonlighting functions,” Rando says. Both studies suggest that the RNA bits alter gene activity. Rando and colleagues blocked one of the tRNA fragments inside embryonic stem cells and increased the activity of about 70 genes. 

Bale says “both papers are really impressive” for digging deep into epigenetic mechanisms. And Nadeau says they should help overcome the challenge of identifying “the molecules that are responsible for inheritance outside of DNA sequences.”

Researchers now need to ask “how permanent these changes are and how quickly they can be reversed by changing diet,” says developmental endocrinologist Susan Ozanne of the University of Cambridge in the United Kingdom. The effects of the RNA fragments don’t have to be harmful, Chen notes. “If a bad diet can influence us, I think a healthy diet can do it in the same way,” he predicts.

Posted in Biology

By  

Mitch Leslie 

http://news.sciencemag.org/biology/2015/12/are-you-inheriting-more-genes-your-father

Novas alternativas de combate ao CA

Estudo publicado por cientistas demonstram que o uso de RNA de interferencia pode reduzir a proliferação de tumores de câncer de próstata.

\HUANG, S.Q. et al. RNAi-mediated knockdown of pituitary tumor- transforming gene-1 (PTTG1) suppresses the proliferation and invasive potential of PC3 human prostate cancer cells. Braz J Med Biol Res [online]. 2012, vol.45, n.11, pp. 995-1001.  Epub Aug 09, 2012 ISSN 1414-431X.  http://dx.doi.org/10.1590/S0100-879X2012007500126.

Pituitary tumor-transforming gene-1 (PTTG1) is a proto-oncogene that promotes tumorigenesis and metastasis in numerous cell types and is overexpressed in a variety of human tumors. We have demonstrated that PTTG1 expression was up-regulated in both human prostate cancer specimens and prostate cancer cell lines. For a more direct assessment of the function of PTTG1 in prostate tumorigenesis, RNAi-mediated knockdown was used to selectively decrease PTTG1 expression in PC3 human prostate tumor cells. After three weeks of selection, colonies stably transfected with PTTG1-targeted RNAi (the knockdown PC3 cell line) or empty vector (the control PC3 cell line) were selected and expanded to investigate the role of PTTG1 expression in PC3 cell growth and invasion. Cell proliferation rate was significantly slower (28%) in the PTTG1 knockdown line after 6 days of growth as indicated by an MTT cell viability assay (P < 0.05). Similarly, a soft agar colony formation assay revealed significantly fewer (66.7%) PTTG1 knockdown PC3 cell colonies than control colonies after three weeks of growth. In addition, PTTG1 knockdown resulted in cell cycle arrest at G1 as indicated by fluorescence-activated cell sorting. The PTTG1 knockdown PC3 cell line also exhibited significantly reduced migration through Matrigel in a transwell assay of invasive potential, and down-regulation of PTTG1 could lead to increased sensitivity of these prostate cancer cells to a commonly used anticancer drug, taxol. Thus, PTTG1 expression is crucial for PC3 cell proliferation and invasion, and could be a promising new target for prostate cancer therapy.

Keywords : PTTG1; Prostate cancer; Cell proliferation; Transwell invasion assay; Anticancer drug resistance.

IDB 2009 Brasil:indicadores e dados básicos para a saúde. O folheto do IDB 2009 destaca o tema da mortalidade causada pelo trânsito de veículos de transporte terrestre no Brasil. Esta é a faceta mais trágica de um grave problema de saúde pública que está a  exigir  ações  intersetoriais  e  intergovernamentais  articuladas,  visando  aperfeiçoar  políticas  públicas regulatórias dos meios e das vias de transporte, de educação no trânsito e de atenção às vítimas de acidentes. O Brasil está entre os dez países do mundo com maior número de mortes causadas pelo trânsito. Em 2008 foram registradas aproximadamente 38 mil mortes por esta causa, representando para a população um risco de 19 óbitos para cada 100 mil habitantes. O mapa da capa mostra a mortalidade por acidentes de trânsito nos municípios brasileiros, representada pelas médias das taxas calculadas para o período de 2006 a 2008. Observa-se ampla distribuição dos valores mais elevados (taxas acima de 30 mortes por 100 mil habitantes), sobretudo na Região Centro-Oeste e em estados das regiões Sul e Sudeste. Na contracapa, estão ilustrados alguns aspectos de interesse para a análise do tema. Os gráficos mostram que a taxa de mortalidade tem se mantido estável desde 2001, após declínio observado entre 1996 a 2000, período no qual se situa a implantação do Código Nacional de Trânsito, em 1998. De modo geral, a mortalidade por esta causa é mais frequente em indivíduos do sexo masculino. Em relação aos grupos etários atingidos, existe uma diferenciação quanto ao tipo de acidente. Os idosos são as principais vítimas de atropelamento; e na faixa etária de 15 a 39 anos predominam os óbitos de motociclistas. Os gráficos apresentam também as tendências da mortalidade por acidentes de trânsito segundo o porte dos municípios. Constata-se que, a partir de 2001, as curvas correspondentes aos municípios com menos de 100 mil habitantes continuaram em ascensão, tendo se estabilizado no caso dos municípios mais populosos. Um dos fatores que explicam essa situação é a precária municipalização do trânsito, especialmente em pequenos municípios, no que concerne à fscalização, educação, sinalização e investimento em infraestrutura viária, entre outros. Outro fato também indicado pelos gráficos é que ao longo dos anos houve declínio na mortalidade de pedestres em todas as regiões do país; entretanto, comportamento inverso foi observado entre motociclistas, para os quais a mortalidade apresenta tendência marcadamente ascendente em todas as regiões brasileiras, em especial, na Centro-Oeste. Esse aumento do risco de morte de motociclistas pode ser atribuído ao contexto social de busca de rapidez em ações e serviços, com facilidade para aquisição de motocicletas e ausência de uma política efetiva de transporte público. Os dados apresentados no folheto representam uma síntese da base completa da RIPSA disponível na página do DATASUS (www.datasus.gov.br/idb) e na BVS–RIPSA (www.ripsa.org.br), nas quais podem ser obtidos dados de séries históricas e informações técnicas detalhadas sobre todos os indicadores, além de indicações sobre a revisão e atualização de dados anteriormente publicados. Os arquivos podem ser visualizados em: http://new.paho.org/bra/index.php?option=com_content&task=view&id=1775&Itemid=347

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