DNA testing: a breakthrough in early disease detection

By Carol Aloysius

Genetic engineering is a relatively new field. Apart from its application to other fields such as crime detection, parentage analysis etc, the medical world is now using this sophisticated technology to detect diseases or confirm their suspicions of virus related diseases such as dengue, hepatitis B and C, HIV, or bacteria caused diseases like TB or parasite borne diseases such as malaria, filarial and worm infestation, in their patients.

“Early detection can significantly cut down the risks of a disease discovered at a later stage, thus avoiding complications. It can save lives”, say scientists at GENOTECH, a leading research institute using DNA to analyse samples of hundreds of suspected cases of diseases caused by viruses, bacteria and parasites commonly found in Sri Lanka.

Molecular diagnostics was first introduced to Sri Lanka by the late Dr Maya Gunesekera, founder of the country's first Molecular Diagnostic lab (Genetech). Since then the GENE lab has analysed thousands of human samples for various purposes including crime investigation.

Now this research institute is reaching out to help doctors battling against various infectious diseases including the current dengue epidemic which though now on the decline, is still prevalent in the country.

Senior Scientist specialising in molecular diagnostic infections at Genetech, Dr Dammika Senevirathne, explains how DNA technology works, and why it is so much better, quicker, and faster for diagnosing diseases than Antibody Testing which is the common procedure used to test suspected cases of dengue in most health facilities in the island.

Following are excerpts from an interview with the Sunday Observer.

Q. There are four different types of Dengue found in the world. What are the most common types found in Sri Lanka?

A. Dengue type 1, 2, 3, and 4.

Q. What type/or types are most common right now?

A. Type 1, But we do have a few cases of Type 4 as well.

Q. What about the other two types?

A. So far there is no evidence of type 2 or type 3 in the samples sent to us for testing.

Q. Are they samples from across the country? Or limited to a few areas?

A. All the samples are from Colombo. But anyone from any part of the country outside Colombo can also send us samples for DNA testing. This service is to help all Sri Lankans.

Q. Is there a correlation between the type of dengue and the age of the victim?

A. Our data does not show any correlation between the sero types and the age of the victims. Transmission is through the vector. No matter what type the mosquito is, the dengue carrying vector attacks everyone irrespective of age, gender or race.

Q. Then why do health officials say children and adolescents are more at risk?

A. Because they are more active than adults and constantly outdoors at day time. So they are more exposed to the vector. Their immunity is also lower as their immune systems are still developing.

Q. What exactly is Genetech's role in minimising dengue risks in this country?

A. We concentrate only on early detection of the dengue infection which is automatically supplied to reduce the complications, and manage patients better.

Q. What does this procedure involve?

A. The work we do can be divided into three stages. At the first stage, we draw a blood sample from the suspect case, and then extract the viral RNA (Ribonucleic Acid) or what is called the viral genetic material.

At stage 2 we magnify a specific fragment of viral RNA using PCR technology (Polymerase Chain Reaction). The 3rd stage is to check the presence of that specific amplified product using a technique known as agarosegel electrophoresis which gives us an image of DNA bands.

Q. How are you be able to say if it is positively dengue or not?

A. If that specific DNA band is present, then we positively identify that patient as being infected with the dengue viral. If it isn't there and even if he has some other disease, it will come up negative as this is a highly specific test, using the PCR machine

This whole process is called Conventional PCR, and was designed for the quantitative detection of micro-organism. There is also another method called RealTime PCR which was specially designed for qualitative detection. Both these methods are available at our lab.

Q. What are the functions of the PCR machine?

A. PCR is the most important piece of technology in any molecular diagnostic lab. What is does, is take the DNA or RNA material and find the highly specific area for that particular organism, through a unique process, and produce multiple copies of that specific piece of fragment. This higher number of copies facilitates the function analysis of that specific DNA fragment. This is the main advantage of using PCR in DNA testing. All our analysis is based on this piece of equipment.

All our analysis is based on this piece of equipment.

Q. What are the advantages of using this technique as against antibody testing?

A. Early detection. Whereas previously we had to wait for at least 4-5 days after onset of symptoms to check the antibodies (IgM and IgG), DNA technique helps us detect the onset of these symptoms even on the first day of the fever.

Q. Does the fever have to be very high to respond to this testing?

A. It depends on the individual. It is possible to detect the virus whether the patient has mild, moderate or high fever or no fever at all.

The last category of patients are however rare. But they can still carry the infection with them even if they don't have any symptoms.

Q. How long will this whole procedure take?

A. Usually about six hours. But the results can be ready within 24 hours.

Q. Is there a time limit for DNA testing?

A. Yes. We recommend DNA testing only within the first four days if they suspect they have contracted the virus, i.e. before the human response starts and before the production of antibodies.

Q. If there is a delay, what happens?

A. If they have passed the initial four days, it is better to go for an antibody testing, because the viral particles no longer exist.

Q. Apart from early detection leading to quicker management of the disease and avoiding complications, are there any other benefits?

A. DNA testing also has high accuracy and sensitivity, allowing very little room for human errors.

Besides this, here in Sri Lanka, patients will have the benefit of highly qualified, efficient scientists.

Q. How many of you are there in the GENE lab?

A. Right now we have around twenty full time research highly qualified scientists, who have developed our own in-house method. This has enabled us to offer our services at very affordable prices.

Q. How much does a test cost?

A. Rs 3,500. It is one of the cheapest rates on offer in any Asian hospital. Which is why we now have an increasing number of clients from abroad, requesting for both diagnostic tests and for DNA typing.

Q. Does a patient have to come to you directly for a test? Or can he send a sample of his blood to the nearest MOH hospital with a request to send it to your lab?

A. A patient can either come to us directly or else through the hospital.

Q. Your message to the public?

A. Many people are still unaware of our services, although Genetech is the first ISO accredited genetic lab in Sri Lanka. We have ISO 15 189, 2007 which is the latest technology available anywhere in the world.

We also constantly update our information and data bank. If a person suspects he/she has symptoms of a specific disease, then an early DNA test will reduce risks of complications developing at a later stage. We have the ability to diagnose over eighty diseases.

Q. What are Genetech's plans for the future?

A. Genetic testing will be the future technology for the medical world. Our aim is to make this technology available to all at the lowest possible price.

Q. Are your staff available any time a person needs to have a blood specimen quickly?

A. Yes. We have a 24 hour hotline and we accept samples at any time of the day and night. The number to call is 0112696992.

Revolutionary ‘biomarker’ for clinical depression in teenage boys

Young men who have depressive symptoms and high cortisol levels are the most susceptible

A revolutionary way of identifying the teenage boys who are most likely to develop clinical depression in later life has been discovered by researchers at the University of Cambridge.

Predicting those who may be at risk of depressive symptoms has been puzzling doctors for decades but now scientists have found the first biomarker - or biological signpost - for clinical depression.

Teenage boys who have a combination of depressive symptoms and raised levels of the stress hormone cortisol are up to 14 times more likely to develop clinical depression than those who show neither trait. Around one in six people suffer from clinical depression at some point in their lives and three-quarters of mental health diseases start before people are 24 years old. Researchers believe this latest discovery, could help target treatment and mean doctors can intervene earlier.

Prof Ian Goodyer from the University of Cambridge, who led the study, said: “Depression is a terrible illness that will affect as many as 10 million people in the UK at some point in their lives. Through our research, we now have a very real way of identifying those teenage boys most likely to develop clinical depression.

“This will help us strategically target preventions and interventions at these individuals and hopefully help to reduce their risk of serious episodes of depression and their consequences in adult life.”

At the moment the indicators work only for men because cortisol levels are higher in women and they have not found an equivalent way of predicting outcomes for female patients.

Researchers analysed several early morning saliva samples taken within a week from more than 1,850 teenagers - and did the same again a year later.

The samples showed cortisol levels were stable over the year and were then combined with self-reports about symptoms of depression.

The teenagers were then divided into four groups, ranging from group one, who had normal levels of morning cortisol and low symptoms of depression over time, through to group four, who had elevated levels of morning cortisol and high symptoms of depression over time. Teenage boys in group four were 14 times more likely to develop clinical depression than those in the first group. Teenage girls in this fourth group were only four times more likely than those in the first group to develop major depression - and were no more likely to develop the condition than those with either high morning cortisol or symptoms of depression alone. The findings suggest gender differences in how depression develops.

John Williams, head of neuroscience and mental health at the Wellcome Trust, said: “Progress in identifying biological markers for depression has been frustratingly slow, but now we finally have a biomarker for clinical depression. The approach taken by Prof Goodyer's team may yet yield further biomarkers. It also gives tantalising clues about the gender differences in the causes and onset of depression.”

The Independent

Scientists hope monkeys could help paralysed people

The technique has been called a “key step forward”

Scientists have developed a way for monkeys to control “avatars” that could be used to help paralysed people move their bodies.

In the tests scientists found that brain signals from the master monkey's mind could be used to stimulate an avatar's spinal cord to control its movements.

The findings published in Natural Communications have been called a “key step forward” and could help people who have damaged their spinal cord to the extent that its stops information flowing from the brain to the body.

People with such damage are often left unable to walk or feed themselves, and researchers say that even the smallest amount of movement could dramatically improve a person's life, the BBC reported.

The scientists from Harvard Medical School in the US envisage their findings could go towards creating machinery to help patients.

As researchers said they could not justify paralysing a monkey for the study, they used a conscious monkey with an implanted brain chip, and an unconscious avatar to be controlled.

During the experiment, the conscious monkey's movements were mapped according to patterns of electrical activity in its neurons. The scientists then hooked the avatar's spinal cord up to 36 electrodes to measure how it moved according to different combinations of stimulation.

In a different test, as the sedated monkey held a joystick, the master thought about moving a cursor up and down.

In 98 percent of tests, the master could correctly control the avatar's arm.

One of the researchers, Dr Ziv Williams, told the BBC : “The goal is to take people with brain stem or spinal cord paralysis and bypass the injury.

“The hope is ultimately to get completely natural movement, I think it's theoretically possible, but it will require an exponential additional effort to get to that point.”

Dismissing claims that the technology could be used to control people's bodies, Prof Christopher James of University of Warwick told the BBC : “Some people may be concerned this might mean someone taking over control of someone else's body, but the risk of this is a no-brainer.

- The Independent

Letter:

Don't let cancer break your spirit

Finding out that you have a cancer can be difficult and stressful.

When I was diagnosed with cancer in October last year I didn't panic but was determined to face the challenge.

My great belief in the Buddha gave me courage to balance my mind and face the situation. I also had great faith in the doctors at Kalubowila Hospital to whom I'm grateful for treating me.

Cancer treatment was challenging and stressful. But I knew that what I was experiencing was not unique and others too are facing the same challenge.

I request fellow citizens irrespective of their education or social background to stop habits such as running behind soothsayers, spiritual or local healers waiting to gamble with your life for their own benefit.

If you have any doubt about your health don't waste time. Go to the correct doctor and get yourself relieved from all your aches and pains.

Time is very important in the case of cancer and every minute you waste means you take a step towards your grave.

Cancer may change your body but don't let your mind and spirit be shaken.

Try to be positive, stress-free and trust your doctors waiting with open arms to give your life back to you.

It is very important to know that cancer patients don't need sympathy but what they need is proper medical attention, love, care and sharing.

I am free of cancer today because of the diligent medical attention of the Doctors and the love, care and sharing showered on me by my children, grand children and true friends who made me feel how much they value me and need me.

Padmini Varnasooriya
Boralesgamuwa.