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How do you make a working human heart? Scientists can turn stem cells into beating heart cells, but getting them to organize into a 3D heart requires a scaffold. At the Massachusetts General Hospital in Boston, Harald Ott and his team are reusing the scaffold that nature provides. They’re stripping away all the living cells from dead hearts, before filling in the leftover matrix with healthy new cells. In this video, Brendan Maher finds out how the technique could be used to develop parts of the heart, like the aortic root and valve, for transplant.
Knee replacement, also called arthroplasty, is a surgical procedure to resurface a knee damaged by arthritis. Metal and plastic parts are used to cap the ends of the bones that form the knee joint, along with the kneecap. This surgery may be considered for someone who has severe arthritis or a severe knee injury.
During the examination, the doctor gently puts a lubricated, gloved finger of one hand into the rectum. He or she may use the other hand to press on the lower belly or pelvic area. A digital rectal exam is done for men as part of a complete physical examination to check the prostate gland .
Encephalitis (en-sef-uh-LIE-tis) is inflammation of the brain. Viral infections are the most common cause of the condition. Encephalitis can cause flu-like symptoms, such as a fever or severe headache. It can also cause confused thinking, seizures, or problems with senses or movement. However, many cases of encephalitis result in only mild flu-like symptoms or even no symptoms. Severe cases of encephalitis, while relatively rare, can be life-threatening. Because the course of any single case of encephalitis can be unpredictable, it's important to get a timely diagnosis and treatment.
Less than a decade ago, corneal transplantation took a big leap forward with the introduction of Descemet’s stripping endothelial keratoplasty (DSEK), which removes only Descemet’s membrane and the diseased endothelium and replaces them with a thin, tripartite donor graft of posterior corneal stroma, Descemet’s membrane, and healthy endothelium. Then came DSAEK, in which the donor graft is prepared with an automated microkeratome, allowing for easier donor preparation and reproducible results by surgeons and eye bank technicians.1 DSAEK has proved to have many advantages over penetrating keratoplasty (PK) and its endothelial predecessors (see “A Brief History of Endothelial Keratoplasty”). Now DSAEK is being compared with a newer technique, Descemet’s membrane endothelial keratoplasty (DMEK), which has emerged as a promising alternative—grafting only Descemet’s membrane and endothelium, allowing for a pure anatomical replacement of only what was removed and the possibility of even better vision with quicker healing.1 Although indications for these procedures are similar, each has unique benefits and drawbacks. Five cornea surgeons offer their perspectives on the procedures and their thoughts on whether it may be time to move to the newer surgery.
The cornea occupies the front center part of the outer wall of the eye. It is made of collagen fibers in a very special arrangement so that the cornea is clear. One looks through the cornea to see the iris and pupil. The cornea bends light coming into the eye so that it is focused on the retina.
You get motion sickness when one part of your balance-sensing system (your inner ear , eyes, and sensory nerves) senses that your body is moving, but the other parts don't. For example, if you are in the cabin of a moving ship, your inner ear may sense the motion of waves, but your eyes don't see any movement.