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Saturday, August 22, 2015

Gut microbes linked to eye disease

Some microbes that naturally dwell in our intestines might be bad for our eyes, triggering autoimmune uveitis, one of the leading causes of blindness. A new study suggests that certain gut residents produce proteins that enable destructive immune cells to enter the eyes.

The idea that gut microbes might promote autoimmune uveitis “has been there in the back of our minds,” says ocular immunologist Andrew Taylor of the Boston University School of Medicine, who wasn’t connected to the research. “This is the first time that it’s been shown that the gut flora seems to be part of the process.”


As many as 400,000 people in the United States have autoimmune uveitis, in which T cells—the commanders of the immune system—invade the eye and damage its middle layer. All T cells are triggered by specific molecules called antigens, and for T cells that cause autoimmune uveitis, certain eye proteins are the antigens. Even healthy people carry these T cells, yet they don't usually swarm the eyes and unleash the disease. That's because they first have to be triggered by their matching antigen. However, those proteins don't normally leave the eye. So what could stimulate the T cells? One possible explanation is microbes in the gut.

In the new study, immunologist Rachel Caspi of the National Eye Institute in Bethesda, Maryland, and colleagues genetically engineered mice so their T cells recognized one of the same eye proteins targeted in autoimmune uveitis. The rodents developed the disease around the time they were weaned. But dosing the animals with four antibiotics that killed off most of their gut microbes delayed the onset and reduced the severity of the disease. The researchers saw the same effects in so-called germ-free mice, which lack gut bacteria.

To test whether gut microbes were stimulating these T cells, Caspi and colleagues added the intestinal contents of the diseased mice to T cell cultures. This gut goop switched on the cells, priming them for eye infiltration. The team wondered whether a protein released by the intestinal microbes was triggering the T cells, so they then added a protein-destroying enzyme to the intestinal mixture. The T cell response was weaker, suggesting they were responding to a protein. In another experiment, the scientists injected T cells from the genetically altered mice into control mice that were not prone to autoimmune uveitis. If these T cells haven’t been exposed to intestinal material, they don’t cause uveitis. But 86% of the animals developed autoimmune uveitis if they received a large dose of T cells that had been exposed to intestinal contents of diseased mice, the researchers report online today inImmunity.

The results suggest that certain bacteria in the intestines produce proteins that closely resemble those in the eye—and can switch on some T cells in the intestines. “We can prove that activation is occurring in the gut,” Caspi says. The activated cells then presumably travel to the eyes, which they enter and start to destroy.

“It’s a very rigorous approach, and it really adds to our knowledge” about the origins of autoimmune uveitis, says ocular immunologist Russell Read of the University of Alabama, Birmingham, who was not involved in the study. One question researchers now need to answer is why we don’t all have these autoimmune reactions in our retinas, says ocular immunologist James Rosenbaum of the Oregon Health & Science University in Portland. It’s possible, he says, that only some people have the bacteria that stimulate the T cells or that certain genes could leave some individuals vulnerable to the disease.

Caspi and colleagues are still trying to find out which gut proteins the T cells recognize and which bacteria produce them. “I don’t want to suggest that popping an antibiotic pill or taking a probiotic is going to be a solution for the disease,” she says. But identifying these molecular mimics of the eye proteins, along with the bacteria that spawn them, could help researchers develop new ways to treat or prevent autoimmune uveitis. 


Posted in BiologyHealth

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How to Digitally Record/Video a UFO sighting:


Como registar digitalmente ou gravar um vídeo de um avistamento de um UFO:




Stabilize the camera on a tripod. If there is no tripod, then set it on top of a stable, flat surface. If that is not possible lean against a wall to stabilize your body and prevent the camera from filming in a shaky, unsteady manner.

Estabilize a camera com um tripé. Se não tiver um tripé, então coloque-a em cima de uma superfície estável. Se não for possível, então encoste-se a uma parede para estabilizar o corpo e evitar que a camera registe de maneira tremida e instável.

Provide visual reference points for comparison. This includes the horizon, treetops, lampposts, houses, and geographical landmarks (i.e., Horsetooth Reservoir, Mt. Adams, etc.) Provide this in the video whenever is appropriate and doesn’t detract from what your focus is, the UFO.

Forneça pontos visuais de referência para comparação. Isso inclui o horizonte, cimo das árvores, postes de iluminação, pontos de referência geográficos (como o Reservatório de Horsetooth, Mone Adams, etc) Forneça esses pontos no vídeo sempre que for apropriado e não se distraia do que é o seu foco, o UFO/a Nave.

Narrate your videotape. Provide details of the date, time, location, and direction (N,S,E,W) you are looking in. Provide your observations on the weather, including approximate temperature, windspeed, any visible cloud cover or noticeable weather anomalies or events. Narrate on the shape, size, color, movements, approximate altitude of the UFO, etc and what it appears to be doing. Also include any unusual physical, psychological or emotional sensations you might have. Narrate any visual reference points on camera so they correlate with what the viewer will see, and thereby will be better able to understand.

Faça a narração do vídeo. Forneça pormenores sobre a data, hora, local e direcção (Norte, Sul, Este, Oeste) que está a observar. Faça observações sobre as condições atmosféricas, incluindo a temperatura aproximada, velocidade do vento, quantidade de nuvens, anomalias ou acontecimentos meteorológicos evidentes. Descreva a forma, o tamanho, a cor, os movimentos, a altitude aproximada onde se encontra o UFO/nave, etc e o que aparenta estar a fazer. Inclua também quaisquer aspectos pouco habituais de sensações físicas, psicológicas ou emocionais que possa ter. Faça a narração de todos os pontos de referência visual que o espectador irá ver e que, deste modo, será capaz de compreender melhor.

Be persistent and consistent. Return to the scene to videotape and record at this same location. If you have been successful once, the UFO sightings may be occurring in this region regularly, perhaps for specific reasons unknown, and you may be successful again. You may also wish to return to the same location at a different time of day (daylight hours) for better orientation and reference. Film just a minute or two under “normal” circumstances for comparison. Write down what you remember immediately after. As soon as you are done recording the experience/event, immediately write down your impressions, memories, thoughts, emotions, etc. so it is on the record in writing. If there were other witnesses, have them independently record their own impressions, thoughts, etc. Include in this exercise any drawings, sketches, or diagrams. Make sure you date and sign your documentation.

Seja persistente e não contraditório. Volte ao local da cena e registe o mesmo local. Se foi bem sucedido uma vez, pode ser que nessa região ocorram avistamentos de UFOs/naves com regularidade, talvez por razões específicas desconhecidas, e talvez possa ser novamente bem sucedido. Pode também desejar voltar ao mesmo lugar a horas diferentes do dia (durante as horas de luz)para ter uma orientação e referência melhor. Filme apenas um ,inuto ou dois em circunstâncias “normais” para ter um termo de comparação. Escreva tudo o que viu imediatamente após o acontecimento. Logo após ter feito o registo da experiência/acontecimento, escreva imediatamente as impressões, memórias, pensamentos, emoções, etc para que fiquem registadas por escrito. Se houver outras testemunhas, peça-lhes para registar independentemente as suas próprias impressões, pensamentos, etc. Inclua quaisquer desenhos, esbolos, diagramas. Certifique-se que data e assina o seu documento/testemunho.

Always be prepared. Have a digital camera or better yet a video camera with you, charged and ready to go, at all times. Make sure you know how to use your camera (and your cell phone video/photo camera) quickly and properly. These events can occur suddenly, unexpectedly, and often quite randomly, so you will need to be prepared.

Esteja sempre preparado, Tenha sempre uma camera digital, melhor ainda, uma camera vídeo consigo, carregada e pronta a usar sempre que necessário. Certifique-se que sabe como lidar com a sua camera (ou com o seu celular/camera fotográfica) rápida e adequadamente. Esses acontecimentos podem acontecer súbita e inesperadamente e, por vezes, acidentalmente, por isso, necessita estar preparado.

Look up. Be prepared. Report. Share.

Olhe para cima, Esteja preparado, Relate, Partilhe.

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