Detecting eye diseases by a simple eye scan

A team of international scientists at the Massachusetts Institute of Technology has developed a new hand-held optical device that simply scans the retina to detect whether a person is suffering from eye diseases such as diabetic retinopathy, glaucoma and macular degeneration.

The tool, which is about the size of a hand-held video camera, scans a patient's entire retina in seconds and could aid primary care physicians in the early detection of a host of retinal diseases.

Although other research groups and companies have created hand-held devices using similar technology, the new design is the first to combine cutting-edge technologies such as ultrahigh-speed 3-D imaging, a tiny micro-electro-mechanical systems (MEMS) mirror for scanning, and a technique to correct for unintentional movement by the patient. The instrument uses a technique called optical coherence tomography (OCT) that sends beams of infrared light into the eye and onto the retina. Echoes of this light return to the instrument, which uses interferometry to measures changes in the time delay and magnitude of the returning light echoes, revealing the cross sectional tissue structure of the retina-similar to radar or ultrasound imaging.

Tabletop OCT imagers have become a standard of care in ophthalmology, and current generation hand-held scanners are used for imaging infants and monitoring retinal surgery. The researchers were able to shrink what has been typically a large instrument into a portable size by using a MEMS mirror to scan the OCT imaging beam.

They tested two designs, one of which is similar to a handheld video camera with a flat-screen display. In their tests, the researchers found that their device can acquire images comparable in quality to conventional table-top OCT instruments used by ophthalmologists. By using multiple 3-D images of the same part of the retina, it is possible to correct for distortions due to motion of the operator's hand or the subject's own eye.

But the device is still relatively expensive, he added, and before this technology finds its way into doctors' offices or in the field, manufacturers will have to find a way to support or lower its cost.

SAGE test for Alzheimer's Disease

New research suggests that early symptoms of the Alzheimer’s disease could now be detected early with the help of a 15-minute home-based test, meaning potential treatments could be started much earlier. The new pen-and-paper-based test, called the Self-Administered Gerocognitive Examination (SAGE), consists of four interchangeable forms and takes approximately 15 minutes to complete.

The test determines the cognitive abilities of each patient by assessing the following areas:

• Orientation (the month, date and year)
• Language (verbal fluency and picture naming)
• Reasoning/computation (abstract and calculation)
• Visuospatial (3D construction and clock drawing)
• Executive (problem solving) and memory abilities

Patients can achieve a maximum of 22 points on the test, and missing six or more points may warrant a follow-up visit to a clinician, according to the researchers. This test can be carried out in almost any setting, such as at home, and prove useful in terms of early detection of cognitive impairment.

For more details and to go through the test, please click here

The sunshine vitamin

Vitamin D deficiency is fast becoming a global and national health concern. It is estimated that around 75% of the Indian population has Vitamin D levels less than normal. However, the bigger concern is that the population at large is not even aware of Vitamin D deficiency and its consequences.

Vitamin D is a pro-hormone that influences the expression of more than 200 genes in the human body. Nearly every tissue in the human body has receptors of vitamin D, be it the brain, heart, skin, kidney, pancreas etc. Any deficiency of vitamin D in the human body is bound to affect normal functioning of all organs having Vitamin D receptors.

Earlier, vitamin D was thought to be responsible for maintaining calcium homeostasis to prevent osteoporosis and maintain bone health. But, in the past decade, research has established the strong association of vitamin D deficiency in diabetes, immunity, asthma, TB, high blood pressure, neuro-muscular function, etc. Low level of vitamin D is associated with higher incidence of type 2 diabetes and correcting Vitamin D deficiency improves insulin sensitivity and helps in better management of hyperglycemia. Also vitamin D deficiency has been associated with high incidence of type 1 diabetes.

As the mother is the sole source of vitamin D substrate for her developing foetus, vitamin D status is very important during pregnancy. Maternal deficiency of vitamin D is linked with abnormal foetal growth and gestational diabetes. Sunscreen lotions, staying indoors, clothing habits, pollution and minimal exposure to direct sunlight (during the period of 10am to 3pm) are the major reasons of such widespread deficiency in the Indian population.

Given the fact that vitamin D receptors are present in various organs and tissues of the human body, maintaining vitamin D levels in blood above 30 ng/ml may ensure normal functioning of the body organs and protect many from suffering from chronic ailments.

Scientists successfully grow artificial human 'mini-brains'

The researchers from the Institute of Molecular Biotechnology at the Austrian Academy of Sciences have successfully grown complex human brain tissue from stem cells using a new 3D culture system.

They have modified an established approach to generate so-called neuroectoderm, a cell layer from which the nervous system derives. Fragments of this tissue were maintained in a 3D-culture and embedded in droplets of a specific gel that provided a platform for complex tissue growth. In order to enhance nutrient absorption, they later transferred the gel droplets to a spinning bioreactor. Defined regions of the brain - including a cerebral cortex, retina, meninges and a choroid plexus - developed after 20-30 days. After 2 months, full size "mini-brains" had been created that have continued to survive in a spinning bioreactor, and they are currently surviving at 10 months.

The researchers say that this method could potentially be used to create "model systems" for human brain disorders and will eventually allow for the study of a variety of neurodevelopment processes specific to human brain development.

Maternal vitamin D levels could affect child later in life

The investigators from University of Southampton in the UK suggest that mothers who have a higher intake of vitamin D during pregnancy are more likely to have children with stronger muscles.

Vitamin D is known to help regulate the amount of calcium and phosphate in the bloodstream, as well as help cells to communicate. Previous research has linked low vitamin D levels to decreased muscle strength in children and adults, but the researchers say there is little knowledge on how a child may be affected by their mother's vitamin D intake during pregnancy. To find out more, the researchers measured the vitamin D levels of 678 pregnant women at 34 weeks gestation. They found that mothers who had high levels of vitamin D had children with a much higher grip strength compared with the children of mothers who had low vitamin D levels.

Muscle strength peaks in young adulthood before declining in older age and low grip strength in adulthood has been associated with poor health outcomes including diabetes, falls and fractures. It is likely that the greater muscle strength observed at 4 years of age in children born to mothers with higher vitamin D levels will track into adulthood, and so potentially help to reduce the burden of illness associated with loss of muscle mass in old age. This work should help us to design interventions aimed at optimizing body composition in childhood and later adulthood and thus improve the health of future generations.

A new method to detect malaria infection within seconds

An advanced, non-invasive technology can now accurately detect even the low levels of malaria infection through the skin within seconds using a laser scanner that doesn't need dyes, diagnostic chemicals, or needles. This technology is developed by the Dept. of Biochemistry and Cell Biology in Physics & Astronomy at Rice University, USA

Malaria, one of the world's deadliest diseases, kills more than 600,000 people each year, most of them being young children. An efficient epidemiological screening and early diagnosis of the disease is a major challenge in the countries affected by the disease.

This is the first through-the-skin method that's been shown to rapidly and accurately detect malaria in seconds without the use of blood sampling or reagents, It just requires a single person to place a finger on a laser apparatus.

The test involves passing a low-powered laser beam through the skin that creates tiny vapor "nanobubbles" inside malaria-infected cells. Due to a particular wavelength set in the apparatus the laser beam is absorbed only by malaria infected cells and subsequently the parasite bursts out. This device can be handled by non medical personnel and approximately 200,000 people could be screened in a year. In addition it's a painless method of testing which surpasses blood withdrawal requirement with 100% accuracy.

Vitamin E & Alzheimer's Disease

Vitamin E is a group of eight fat-soluble compounds and is naturally found in many foods, including eggs, fortified cereals, fruit, green leafy vegetables, meat, nuts, poultry and vegetable oils. New research suggests that a daily dose of vitamin E may help to slow functional decline for patients with mild to moderate Alzheimer's disease.

Alzheimer's disease is a neurological disorder in which the death of brain cells causes memory loss and cognitive decline. A neurodegenerative type of dementia, the disease starts mild and gets progressively worse.

According to the research team at Minneapolis VA Health Care System, vitamin E acts as an antioxidant in patients with severe Alzheimer's disease. The studies have shown that the vitamin was effective in slowing progression of moderately severe Alzheimer's disease. Results of the study revealed that patients who received the vitamin E had a 19% reduction in functional decline. This is the equivalent to a "clinically meaningful delay in progression" of 6.2 months.

However, Doug Brown, director of research and development of the Alzheimer's Society in the UK, says that patients should be aware that the dosage of vitamin E taken in this study is significantly higher than the adult upper recommended daily allowance of 1,500 IU/day and may be harmful for some."While this study into the link between vitamin E intake and reduction in functional decline is of interest, it is by no means conclusive. More research is needed to see if vitamin E really does have benefits for people with dementia, and whether it would be safe to be taking such a high dose on a daily basis," he adds.

But the researchers say their findings oppose previous studies suggesting that high doses of vitamin E may increase the risk of all-cause mortality."We found no significant increase in mortality with vitamin E. The annual mortality rate was 7.3% in the alpha tocopherol group vs. 9.4% for the placebo group," they add.