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December 25, 2005, 10:32 AM CT

Merry Christmas To All Our Readers

Merry Christmas To All Our Readers
Medicineworld wishes all our readers merry Christmas.

Oh, jingle bells, jingle bells
Jingle all the way
Oh, what fun it is to ride
In a one horse open sleigh
Jingle bells, jingle bells
Jingle all the way
Oh, what fun it is to ride
In a one horse open sleigh

A day or two ago
I thought I'd take a ride
And soon Miss Fanny Bright
Was seated by my side
The horse was lean and lank
Misfortune seemed his lot
We got into a drifted bank
And then we got upsot

Oh, jingle bells, jingle bells
Jingle all the way
Oh, what fun it is to ride
In a one horse open sleigh
Jingle bells, jingle bells
Jingle all the way
Oh, what fun it is to ride
In a one horse open sleigh yeah

Daniel      Permalink


December 21, 2005

Light-sensing cells in retina

Light-sensing cells in retina
Investigators at Washington University School of Medicine in St. Louis have found that cells making up a non-visual system in the eye are in place and functioning long before the rods and cones that process light into vision. The discovery should help researchers learn more about the eye's non-visual functions such as the synchronization of the body's internal, circadian clock, the pupil's responses to light and light-regulated release of hormones.

The scientists report in the Dec. 22 issue of Neuron that in the mouse retina, intrinsically photosensitive retinal ganglion cells (ipRGCs) are active and functioning at birth. That was surprising because the mouse retina doesn't develop fully until a mouse is almost three weeks old, and the first rod cells don't appear until about 10 days after birth.

"We were stunned to find these photoreceptors were firing action potentials on the day of birth," says Russell N. Van Gelder, M.D., Ph.D., associate professor of ophthalmology and visual sciences and of molecular biology and pharmacology. "Mice are very immature when they're born. It takes about three weeks after birth for the retina to fully develop. No one previously had detected light-dependent cell firing in a mouse before 10 days."

Van Gelder says the ganglion cells react to light in two ways, sending messages to parts of the brain that control circadian rhythms, and (on the first day or two of life) also setting off a wave of activity that spreads through the retina, possibly helping visual cells develop.

Van Gelder and his colleagues have spent the last few years learning how blind animals (and people) can sense light and use it to set their circadian clocks. The ipRGCs were first identified in 2002 - by David M. Berson, Ph.D., and his colleagues at Brown University - as the cells that could sense light even in visually blind eyes. But it was very difficult and time consuming to isolate and study the cells, requiring precise injection of a tracing dye into the brains of animals to label and identify the ipRGCs.........

Mike      Permalink


December 18, 2005

Eye Cell Implants Improve Motor Symptoms

Eye Cell Implants Improve Motor Symptoms
A preliminary study suggests that implants of cells from the human retina improved motor symptoms in patients with Parkinson disease, and they appear to be safe and well tolerated, according to a report in the recent issue of the Archives of Neurology, one of the JAMA/Archives journals.

Parkinson disease (PD) is a neurodegenerative disorder characterized by tremor, rigidity, postural instability, and slowed ability to start and continue movements. Most patients with PD require treatment with the medicine levodopa to control symptoms three to five years after a diagnosis of PD. However, disease progression and long-term oral therapy with levodopa may lead to the development of motor fluctuations and dyskinesias (difficulty or distortion in performing voluntary movements). Human retinal pigment epithelial (RPE) cells produce levodopa and can be isolated from post mortem human eye tissue, grown in culture, and implanted into the brain attached to microcarriers. These implants have ameliorated the motor deficits in animal models of Parkinson disease, according to background information in the article. (The retinal pigment epithelium is the pigment cell layer found in the inner layer of the retina of the eye.)

Natividad P. Stover, M.D., of the University of Alabama at Birmingham, and his colleagues conducted an open-label pilot study to evaluate the effect of unilateral implantation of human RPE cells attached to gelatin microcarriers. Six patients with advanced Parkinson disease received cell implants, which were inserted into the brain tissue. The scientists performed efficacy evaluations at one and three months after surgery, and then at six, nine, 12, 15, 18 and 24 months. Yearly follow-up visits are ongoing and will continue.

"The implants were well tolerated," the authors report. "We observed an average improvement of 48 percent at 12 months after implantation in the Unified Parkinson's Disease Rating Scale motor subscore with the patient in the off state, which was sustained through 24 months." .........

Mike      Permalink


December 17, 2005

Gene Mutation In Bardet-beidl Syndrome (BBS)

Gene Mutation In Bardet-beidl Syndrome (BBS)
Johns Hopkins researchers studying a rare inherited syndrome marked by eye and kidney problems, learning disabilities and obesity have discovered a genetic mutation that makes the syndrome more severe but that alone doesn't cause it. Their report appears in the advance online edition of Nature (Dec. 4).

The new discovery about Bardet-Beidl syndrome (BBS) came from a panoply of studies -- starting with comparative genomics and experiments with yeast, and moving to experiments with zebrafish and genetic analysis of families with the syndrome -- and mirrors what experts expect for the genetically complex common diseases that kill most Americans, like diabetes, heart disease and cancer.

"Researchers are going to have to think very hard before they discount genetic variation that appears not to directly cause a disease," says the study's leader, Nicholas Katsanis, Ph.D., associate professor in the McKusick-Nathans Institute of Genetic Medicine at Johns Hopkins. "The onus is on us to figure out how to dissect the effects of what appear to be silent genetic variants. I have a greatly renewed respect for the complexity of the genome, for the subtle ways that genes and gene products interact with each other".

Conventional wisdom says that a collection of subtle genetic variations contribute to a person's risk of common diseases, but hunting for such subtle effects is daunting. As a result, most gene hunts have targeted relatively rare diseases that appear from their pattern in families to be fairly simple genetically.

Katsanis and colleagues have recognized for years that BBS, eventhough rare, is more similar to the genetic complexity of common diseases, in part because patients with this condition have extremely variable severity, even within families. The newly identified mutation, in a gene called MGC1203, is the first to affect only the severity of the syndrome. Mutations in eight other genes, all dubbed BBS genes, are known to cause the disease, often in combination with each other.........

Sue      Permalink


December 14, 2005, 8:11 PM CT

Depression Improves After Epilepsy Surgery

Depression Improves After Epilepsy Surgery
Depression and anxiety are common problems for people whose epilepsy cannot be controlled by medication. A new study found that depression and anxiety improve significantly after epilepsy surgery.

The study, which is published in the December 13, 2005, issue of Neurology, the scientific journal of the American Academy of Neurology, found that the rate of depression and anxiety disorders decreased by more than 50 percent up to two years after the surgery. People who no longer experienced any seizures after surgery were even more likely to be free of depression and anxiety.

"These results are important because depression and anxiety can significantly affect the quality of life," said study author Orrin Devinsky, MD, Professor of Neurology, Neurosurgery, and Psychiatry at New York University School of Medicine and Director of the NYU Comprehensive Epilepsy Center. "For people with refractory epilepsy, studies show that depression is more likely to affect their quality of life than how often they have seizures or how a number of drugs they have to take.".

The study involved 360 people in seven U.S. epilepsy centers who were undergoing epilepsy surgery to remove the area of the brain producing the seizures. Epilepsy surgery is generally reserved for those whose seizures cannot be adequately controlled by medication. The majority of participants had surgery on the brain's temporal lobe. The participants' mental health and any symptoms of depression and anxiety were evaluated before surgery and at three months, one year, and two years after surgery.

Previous to the surgery, 22 percent of the participants met the criteria for a diagnosis of depression, compared to 9 percent two years after the surgery. For anxiety disorders, 18 percent met the criteria for a diagnosis before the surgery, compared to 10 percent two years after the surgery.........

Mike      Permalink


December 14, 2005, 8:5 PM CT

Squinting While Staring At A Computer

Squinting While Staring At A Computer
Squinting at a computer screen can cut in half the number of times someone blinks each minute. And that could lead to an irritating condition called dry eye, new research suggests.

The more that the participants in this study squinted their eyes, the less they blinked. And the less they blinked, the more their eyes ached or burned, and the more they reported sensations of dryness, irritation and tearing.

Just a slight amount of squinting reduced blink rates by half, from 15 blinks a minute to 7.5 blinks a minute.

"People tend to squint when they read a book or a computer display, and that squinting makes the blink rate go way down," said James Sheedy, the study's lead author and a professor of optometry at Ohio State University. "Blinking rewets the eyes. So if your job requires a lot of reading or other visually intense work, you may be blinking far less than normal, which may cause eye strain and dry eye."

Squinting serves two purposes: It improves eyesight by helping to more clearly define objects that are out of focus. It also cuts down on the brightness from sources of glare. It may be voluntary or involuntary - a person working at a computer may not realize that he is squinting.

Dry eye is commonly treatable with over-the-counter eye drops. It's rarely a debilitating condition, but it can be irritating and painful.

The results appear in a January issue of the journal Optometry and Vision Science. Sheedy conducted the study with Ohio State colleagues Sowjanya Gowrisankaran, a graduate student, and John Hayes, a research scientist in optometry.

The scientists asked 10 college students to squint at different levels. All participants had 20/20 vision in both eyes. The scientists attached two tiny electrodes to the lower eyelids of each student. The electrodes were also attached to an electromyogram, a machine that records the electrical activity of muscles. In this case, the scientists wanted to record the action of the orbicularis oculi muscle, which encircles the eye socket and allows the eye to both blink and squint. The electromyogram measured the different degrees of squint.........

Mike      Permalink


December 14, 2005

Intraocular Lens Implant Reduces Need For Reading Glasses

Intraocular Lens Implant Reduces Need For Reading Glasses
Ophthalmologists at Mayo Clinic are implanting a new intraocular lens (IOL) during cataract surgery that promises to reduce or eliminate the need for reading glasses. Standard IOL implants are monofocal. They correct for distance vision but not close-up vision. For activities like reading or working on a computer, patients who've had cataracts removed commonly require reading glasses. The Food and Drug Administration (FDA) approved the ReSTOR lens in March. In the clinical trial to gain FDA approval, 80 percent of patients who had the lens implanted reported they no longer needed glasses for any activity.

"To me the greatest thing this lens offers is freedom," says Mayo Clinic ophthalmologist Dr. Akbar Hasan. "You can focus at different depths. You can go into a grocery store, look down the lane and then pick up a can of soup and read the ingredients. You don't have to reach for your glasses." Dr. Hasan is quick to point out that the new lens doesn't offer better quality vision than standard implants, but rather, less dependence on reading glasses.

A cataract is a clouding of the normally clear lens of the eye. It can occur in one or both eyes and generally occurs as part of the normal aging process. In fact, about 70 percent of all Americans over 75 have a significant degree of visual impairment due to cataracts. Cataract surgery, in which the clouded lens is removed and replaced with an artificial one, is one of the most usually performed operations, and IOL implants have been used for over 30 years. "It's a 15-minute operation," Hasan says. "Recovery is quick. People are back on their feet the same day. Commonly their vision stabilizes within a few days."

Sandra Jones, an accountant at a realty office, was both nearsighted and farsighted. Today she wears neither glasses nor contact lens, though she had relied on them since she was a child. Weeks ago, Hasan placed a ReSTOR IOL in both her eyes. "It far exceeded my expectations," Jones says. "I never thought it would be this good. I can read the phone book without glasses, and that's about as small as it gets."........

Mike      Permalink


December 14, 2005

Cataract Surgery Rates And Costs

Cataract Surgery Rates And Costs
A system in which physicians are reimbursed for each procedure they perform (fee-for-service) is associated with a significantly higher rate of cataract surgery and related surgical costs, compared to a system in which physicians receive a lump sum for each patient they manage (contact capitation), as per a studyin the recent issue of the Archives of Ophthalmology, one of the JAMA/Archives journals.

A variety of studies have evaluated the influence of clinician incentive and reimbursement systems on the provision of services. A number of of those studies have evaluated practice patterns in the primary care setting, and the majority of them confirmed expectations that financial incentives to provide less care result in decreased hospitalization, resource use, and costs, eventhough not universally, according to background information in the article. Under the fee-for-service (FFS) system, physicians are reimbursed for each procedure, and under the contact capitation (CC) system, physicians are provided a lump sum for each patient they manage.

William Shrank, M.D., MSHS, who was with the Veterans Affairs Greater Los Angeles Health Care System at the time of the research, and his colleagues compared the effects of FFS and CC on cataract extraction rates and costs. (Dr. Shrank is now with Brigham and Women's Hospital, Harvard Medical School, Boston.) The scientists analyzed claims and other data for an average of 91,473 commercial beneficiaries and 14,084 Medicare beneficiaries receiving eye care from a network of ophthalmologists and optometrists in St. Louis, Mo., between 1997 and 1998. The rate of cataract extractions per 1,000 beneficiaries, the costs of cataract procedures, the rates of non-cataract procedures, and the level of professional reimbursement for providers were compared during the final six months of FFS clinician reimbursement and the first six months of CC.........

Mike      Permalink


December 12, 2005

Eye's Structure, Muscles Engineered

Eye's Structure, Muscles Engineered
The design of the eye and the muscles and bone that surround it help the brain manage certain complex aspects of eye movement, according to scientists at Washington University School of Medicine in St. Louis. The finding, published in Neuron, may help push an old debate about how eye movement is controlled toward resolution and help eye surgeons better diagnose and treat disorders such as strabismus (crossed eyes) that lead to misalignment of the eyes.

The task of orienting the eyes is more complicated than it might seem at first glance, notes senior investigator Dora Angelaki, Ph.D., Alumni Endowed Professor of Neurobiology.

When we roll our head sideways, our eyes must counter-roll or move in the opposite direction to keep the visual world stable on the retina," Angelaki explains. "This is a well-studied reflex called the vestibulo-ocular reflex or VOR, and it's what lets us see clearly when we walk, drive a car or turn around to see a friend."

Adding to the complexity, rotation of a round, three-dimensional object such as the eye has a property known as non-commutativity. This means that the result of a series of motions - a quarter-turn left and a half-turn up, for example - is dependent on the order in which those motions are performed. Reverse the order of two steps in the series of motions, and the end result is different.

Researchers began to debate in the late 1980s whether the complexities of these problems were handled solely by signals from the brain or accomplished via contributions both from the brain and from the eye. The latter group theorized that the "motor plant" of the eye - which includes the eye, the orbit or eye socket and the muscles that pull on it - could handle some aspects of these tasks without input from the brain. The different models suggested very different things about the way the brain controls eye movement.........

Mike      Permalink


December 12, 2005

Clinical Trial for New Ocular Prosthetic Device

Clinical Trial for New Ocular Prosthetic Device
Emory Eye Center has begun a new clinical trial to evaluate the efficacy of a new prosthetic ocular device, made by Porex Surgical, Inc. The device, the MEDPOR ATTRACTOR Magnetic Coupling System, will offer patients who need a prosthetic eye a better alternative than ever before.

Those needing a prosthetic eye include patients who have had recent enucleations (eye removal) due to trauma or disease and congenital disorders.

"The new device provides our patients with a more realistic prosthetic eye because of a magnetic attraction that can improve the eye's movement," says Robert Bernardino, MD, oculoplastics specialist at Emory Eye Center. "Because the prosthetic eye is vital to making a patient feel whole again, this new one, which provides better movement of the prosthetic eye, is helping their comfort level."

BACKGROUND Porex Surgical, Inc. (Newnan, Ga.) is a manufacturer of medical devices and is the maker of MEDPOR porous polyethylene implants, used for craniofacial reconstruction, and of the MEDPOR ATTRACTOR (TM) Magnetic Coupling System.

MEDPOR Spheres and related shapes are designed for reconstruction of the anophthalmic socket, the condition resulting from the removal of the eye due to trauma or disease. The MEDPOR Implant is placed within the socket and covered with the pink conjunctival tissues after the eye is removed.

After healing, a prosthetic eye, (usually called a "Glass Eye" eventhough made of acrylic plastic), painted to look like a real eye, and shaped like a thick contact lens, is placed in the socket behind the eyelids and over the tissue covered implant. The MEDPOR Implant often moves within the socket in the same way a normal eye will move, but this motion is only partially transmitted to the prosthetic eye, resulting in an unnatural appearance when the patient looks around.........

Mike      Permalink




Did you know?
Medicineworld wishes all our readers merry Christmas. Oh, jingle bells, jingle bells Jingle all the way

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