Biomedical Engineering News

Shiga toxin is a dangerous by-product of certain infectious bacteria, such as strains of Shigella and E. coli, which causes symptoms ranging from intestinal pain to kidney failure and even death. Over 150 million people are afflicted with Shiga toxicosis every year, mostly in developing countries where waterborne diseases are prevalent. It is estimated that Shiga toxins kill more than one million people annually, and is particularly lethal to children. Even in developed countries, Shiga toxicosis remains a threat via foodborne outbreaks.

While exploring the inner workings of the cell, scientists at Carnegie Mellon discovered that Shiga toxin exploits the GPP130 protein found in the Golgi apparatus. As described in their article for the January 20th issue of Science, when a harmful substance enters the cell, it is normally packaged by the Golgi apparatus and sent to the lysosome for degradation. GPP130, however, is an unusual protein that cycles from the Golgi apparatus to endosomes and back without crossing paths with the lysosome. This feature of the GPP130 is utilized by the Shiga toxin which binds to the protein to avoid detection allowing it to remain in the cell where it can cause harm.

However, when high levels of manganese infiltrate the cell, GPP130 alters its pathway to go directly to the lysosome. Beyond a certain point, manganese is also toxic to humans, but the concentrations and methods of administration are already well-documented.

“Manganese is inexpensive. While Shiga toxin affects people in the developed world, it affects far more people in the developing world. An inexpensive, accessible treatment– not a designer drug — is the ideal solution,”  says Adam Linstedt, professor of biological sciences at Carnegie Mellon. “While further testing is needed to determine if manganese is a suitable treatment for humans, I’m optimistic that trials should move forward quickly.

Current treatment methods utilize antibiotics to kill the Shiga-excreting bacteria, which actually causes them to lyse (or break apart) and release the toxin in higher concentrations to the detriment of the host. The researchers propose using manganese in conjunction with the antibiotics to neutralize the toxin as well as the bacteria simultaneously. If the scientists are successful in balancing the manganese dosage and the proper supply chain avenues are set up, millions of lives could be saved.

Qualcomm Life, a subdivision of the major telecom product company that aspires to be a market leader in the developing wireless health network, recently unveiled their new 2net™ Platform and Hub.  Qualcomm Life was formed last week as a wholly owned subsidiary to operate the formerly known Qualcomm Wireless Health. 2net™ includes a wireless hub hardware that integrates signals from many health monitoring devices around the home, collects and encrypts the data,  then sends it to the cloud for physicians or other permitted parties to view.

Roughly 133 million Americans suffer from chronic diseases and their homes are littered with health monitoring devices such as blood pressure monitors or glucose meters. These devices collect data that would greatly benefit health providers in making more efficient treatment decisions if only they had access to that data.

While it is possible to use apps on smartphones to collect and transmit health data, not all signals from the array of health monitoring devices can communicate with smartphone technology. Qualcomm Life Vice President Rick Valencia purports that the new 2net™ Platform not only meets all medical standards, but is “technology agnostic, and can pair with virtually anything”. Qualcomm life is in the process of establishing partnerships with several device manufacturers and their case studies show positive results for the growing wireless healthcare user market.

“There are plenty of apps that will monitor your heart rate or glucose, but if it’s involved in any clinical decision making, that will need to be sent over secure channels and have backup capabilities,” says Andy Castonguay, principal analyst for handsets and devices at Informa.

2net™ is likely the first product on the market with its level of connectivity, security and ease-of-use. 2net™ Platform will probably include a service fee, but Qualcomm Life supports that the convenience and widely informative technology will be worth the price.

Patients that suffer from macular degeneration may regain their vision with the help of an implantable telescope.

Macular degeneration is a progressive disease in which a portion of the retina, called the macula, no longer functions properly. The retina, and particularly the macula, is the anatomical structure that converts light waves into electrical signals to be sent to the brain. When the macula degenerates, only the light that comes in from the peripheral vision (to non-macular areas) can be seen. External magnification devices such as contacts or glasses do not help because the macula does not function.

VisionCare Ophthalmic Technologies has developed a pea-sized device that is implanted in the eye that can magnify visual information entering the eye by almost three-fold. More importantly, it takes light that comes into the eye and refracts to a place on the retina that has not been affected by the disease (a non-macular area). So instead of relying on a degenerated macula to harness and convert light information, areas of the retina that are normally used for peripheral vision are now providing sight for that eye.

The device is only implanted in one of the two eyes despite the fact that macular degeneration usually affects both eyes. The main reason for relegating treatment to one eye is that once the telescope implant is in place, the patient no longer has adequate peripheral vision in that eye. Thus peripheral vision is up to the non-treated eye. In other words, the eye with the telescope is used for central vision while the untreated eye (still with macular degeneration) supplies the patient with peripheral vision.

This device is not for everyone, at least not in this stage of development. In fact doctors that implant the devices must screen out about 80% of patients because they do not meet eligibility requirements. Patients generally must have end-stage macular degeneration and have failed other medical and surgical treatments for the disease. Also, treated patients require visual physical therapy, of sorts (low vision therapy) to be able to perform activities of daily living after implant surgery.

The FDA has cleared the way for Simbionix Ltd. to manufacture and sell a software/hardware system that simulates surgical procedures. PROcedure Rehearsal Studio is a technological advance over earlier medical simulators in that it incorporates the patient’s own clinical information into the simulation. Instead of using idealized human anatomy, surgeons and interventional radiologists can now practice a given procedure using the patient’s specific anatomy.

PROcedure Rehearsal Studio is currently available for endovascular procedures, such as angioplasty and stenting. The patient undergoes a CT scan with contrast and the results are fed into the simulator program. The program then incorporates this unique information into a detailed surgical simulation. The surgeon controls simulated instruments used in the real endovascular procedure. To improve realism, the interface provides tactile feedback, such as when the catheter brushes up against the inside of the blood vessel or reaches a natural branch in the artery. The operator views the simulated cannula moving toward the intended target through the patient’s overlaid CT images.

The biggest advantage of this new simulator software is that it takes the guesswork out of challenging endovascular procedures. While traditional simulator software can train new surgeons and radiologists to perform an angioplasty or to deploy a stent, the PROcedure Rehearsal Studio prepares physicians of any skill level to negotiate the branches and curves of a patient’s particular anatomy. Thus anomalous anatomical variations do not catch the physician by surprise. While larger clinical studies assessing efficacy and safety are forthcoming, the promise of this software/hardware is that it can reduce the number of complications that arise from endovascular procedures, such as trauma to the blood vessel and hemorrhage.

The Food and Drug Administration has given Teleflex Incorporated the green light to use their Chlorag+ard™ technology on peripherally inserted central catheters for human use. ArrowEVOLUTION PICC is similar to other PICC lines with one distinct advantage: it is impregnated with chlorhexidine molecules. Chlorhexidine is a potent antimicrobial agent that has been used in clinical and research settings to disinfect and sterilize medical equipment. The devices should be available on the market by the end of 2010.

Peripherally inserted central catheters or PICC lines provide intermediate and long term venous access in patients. PICC lines are longer than peripheral IVs with tips that extend to and terminate in central veins. Unlike central venous catheters, however, PICC lines begin in the veins of the limbs. This unique configuration means that they can deliver antibiotics that would be harmful to small veins, parenteral nutrition (food into the veins), and even chemotherapy. PICC lines are easier to insert and have fewer complications than central lines.

Historically, the main complication with long term use of PICC lines was that they could become colonized or laden with bacteria or other microorganisms. When a PICC line becomes infected, it must be removed, the patient’s medication administration is delayed, and the patient may need specific antibiotic or antifungal treatment for the catheter-related infection.

The promise of a chlorhexidine-coated catheter is that the PICC line could be left in place longer as the risk of catheter-related infections decrease. Since the catheter itself is the microorganism’s portal to the bloodstream, the Chlorag+ard™ technology should create a harsh, local environment for microbes and keep the PICC line relatively sterile.

By clearing the product, the FDA has essentially said that it is reasonably safe for use in patients. Only time and clinical research will show if ArrowEVOLUTION PICC lines are actually effective in reducing catheter-related infections.

While injectable drugs for multiple sclerosis (MS) have been available for some time, but Novartis’ fingolimod (Gilenya) is the first oral MS drug approved by the FDA. Gilenya has been shown to slow the progression of MS and to reduce the number of flares that patients experience during the course of the disease. As the first oral medicine that treats the disease rather than just treating symptoms, Gilenya may free patients from the need to give themselves regular needle injections in order to control their disease.

MS is a chronic neurological illness in which the immune system attacks and interferes with the myelin sheath that covers nerve cells in the central nervous system. Similar to an electric cord that no longer has its covering, the bare, myelin-less neurons do not send electrical information properly. This causes a number of neurological problems, from blindness to movement disorders, depending on the nerves that are affected.

Gilenya is a superagonist of sphingosine-1-phosphate receptors on the surface of white blood cells, specifically thymocytes and lymphocytes. White blood cells are one of the main tools of the immune system. In MS, they participate in the attack against myelin. In contrast to an agonist which stimulates a response in a biological tissue, a superagonist stimulates an exaggerated response—beyond what the biological tissue normally produces. Gilenya reduces the number of circulating white blood cells lymphocytes, which means there are fewer cells around to attack myelin and cause symptoms of MS.

While most neurologists have been impressed with the drug’s effectiveness, there is still concern about the side effects. Two patients that took the drug during the study died of diseases that their immune systems normally would have cleared, while other illnesses occurred as a result of depressed immune systems. In other words, Gilenya blocks the autoimmune attack on myelin but may inhibit the immune system to a degree that it cannot fight of infections.

Novartis has already agreed to a five year 5 post-approval safety study for the drug that will follow patients on the drug all over the world. As with any new drug, surveillance of side effects is important to determine the long term safety of the drug. For patients with MS that do not tolerate needles, Gilenya provides the first hope of managing the disease without needles.