July 11, 2012
Blood doping usually involves the hormone growth factor, erythropoietin (EPO), which stimulates red blood cell formation in the bone marrow. Although it occurs naturally in the body, DNA technology can be used to produce EPO in the lab and then injected under the skin.
Why are red blood cells so important?
Red blood cells, or more specifically the haemoglobin (Hb) protein of the red blood cell, binds oxygen in the lungs and carries it to muscles throughout the body. One of the major limiting factors in endurance exercise is oxygen delivery to the working muscles. The more oxygen carrying capacity an athlete has, the better the athlete’s endurance.
How do scientists detect the use of EPO?
The volume of the red cell population in the blood is known as the haematocrit (HCT) and is normally between 41-50% in men, and 36-44% in women. Haemoglobin concentration can also be measured and should fall between 14-17g/dL in men, and 12-15g/dL in women. If blood tests detect high HCT or Hb values, it can indicate the use of EPO. Occasionally, athletes have naturally high HCT or Hb measurements, so testing over extended time periods is essential to determine exceptional values for the individual athlete.
The dangers of EPO doping
Excessive use of EPO can make blood more viscous; putting a strain on the heart muscles and has in many cases led to heart failure. The sport probably most associated with EPO is cycling but many endurance sports including rowing, distance running, triathlons and horseracing have had their fair share of scandal.
June 8, 2012
Legionella pneumophila is a gram negative bacterium (this refers to the characteristics of the bacterial cell wall and is important in determining which antibiotics will be most useful to fight it) and is the causative agent in Legionnaires’ disease.
Once the bacterium has entered the body it invades cells called macrophages. Macrophages are cells of the immune system which normally scavenge cells debris and engulf invading pathogens so they can be destroyed by other cells.
The Legionella pneumophila bacterium, however, is able to replicate itself inside the macrophage instead of being destroyed.
The bacterium is transmitted via tiny airborne droplets that are released when water is disturbed and are then inhaled into the lungs.
The most common sources are cooling towers (suspected to be the case in the current Scottish outbreak), ice machines, hot-tubs, showers, air conditioning systems and any complex potable water system or cooling system.
Once infection has taken hold (between 2-10 days), the immune response initially causes fever, chills, muscle aches, headaches and a cough, similar to flu symptoms.
More serious consequences of infection include kidney and liver damage. Middle aged, elderly people, smokers, and patients with chronic lung conditions have an elevated risk of contracting the disease.
Antibiotics that have good intercellular penetration are most effective against the bacterium, such as tetracyclines or erythromycin.
May 29, 2012
The Pacific bluefin tuna (Thunnus orientalis) on the Californian coast have been found to have ten times the expected levels of radioactive caesium, following the Fukushima nuclear disaster in 2011.
The fish, which spawn in Japanese waters, migrate to the Californian coast to feed and have transported the radioactive particles across the ocean. Several thousand tonnes are caught each year for human consumption but marine scientists do not currently think they pose any harm to human health.
The tuna, tested by scientists at Stony Brook University, New York, contain levels of radioactive caesium averaging 5-10 becquerels (Bq), which is below the accepted safe level for human consumption (100Bq/kg). Scientists warn the levels could rise when the fish return to Japanese waters and are once again exposed to the high levels of radionuclides.
Caesium is often present in seawater as a result of atomic weapons testing but Fukushima was the biggest accidental release of radioactive material into the sea in history. Marine biologists, however, have stumbled upon a silver lining because measuring the rate at which the Fukushima caesium decays will enable them to trace migratory patterns in marine wildlife.
April 12, 2012
A study to be published in next month’s American Journal of Cardiology has confirmed that earlobe creases are associated with coronary artery disease. This research upholds the findings of several other studies, including a 2006 Swedish study, which showed that earlobe creases as a marker for heart disease had a positive predictive value of 80% in people under 40 years old.
The marker is a diagonal crease running from the opening of the ear to the outside tip of the earlobe and is not associated with sleeping position or the wearing of earrings. Having the marker is a higher risk factor than having a family history of heart problems, diabetes or even smoking.
It is not fully understood what causes the crease but it’s probable that it indicates premature aging. The soft tissue of the earlobe contains tiny blood vessels called arterioles and degeneration of the tissue surrounding the arterioles causes the wrinkle to appear. This is similar to the type of change associated with the hardening of the arteries and so is perhaps an insight into what is happening inside the body.
Certain retinal disorders have long been known to correlate with heart disease incidence and now it seems the earlobes are another window to the heart. The association between the earlobe marker and the incidence of heart disease is so strong that it could be a significant independent predictor of any coronary artery disease, according to the authors of the study.
I bet you go and look in the mirror right now…
April 11, 2012
For the last few decades the mainstream press have extolled the virtues of moderate red wine consumption, particularly the possible cardioprotective benefits of resveratrol, found in the skin of red grapes. Sales of red wine have increased dramatically as the masses have embraced the notion of ‘healthy’ drinking but it seems only those truly appreciating the wine reap the cardioprotective benefits.
Once resveratrol reaches the gut it is rapidly converted into another compound called piceatannol and so does not enter the bloodstream. Sipping wine slowly, however, allows the resveratrol to be absorbed intact via the mucous membranes in the mouth, which greatly increases resveratrol blood levels. So perhaps the quaffers should pay heed to the wine connoisseur and pause to appreciate the taste and mouth-feel attributes of the wine, improving their health all the while.
Although many wine drinkers already delight in savouring a good red on the palate, it’s not all bad news for the quaffers. New research by scientists at Purdue University, Indiana, indicates that piceatannol, the breakdown product of resveratrol, might have its own health benefits. The study, published in this week’s issue of The Journal of Biological Chemistry, reports that piceatannol prevents fat cells from maturing, thereby arresting fat cell formation. Although still in its preliminary stages it has potential implications for combating rising obesity levels and preventing weight gain.
As noteworthy as the research is, it presents a serious dilemma to the red wine drinker: sip to save your heart or quaff to quell the weight? Sciencegirl thinks it’s probably wise to have two glasses on the go, one for sipping and one for quaffing. Just to be sure, of course.
April 3, 2012
An estimated 150,000 people in the UK have a stroke each year and more than a third die within a week. For those who do survive, rehabilitation is a lengthy process and stroke patients occupy up to 25% of long-term hospital beds.
Stroke victims are often left with impaired communication, known as aphasia. The most common problem is anomia, a condition in which the patient is unable to find the right word to say (a very severe form of everyone’s ‘tip of the tongue’ experiences). Traditional therapy to treat anomia is extensive and requires intervention over a long time period to be successful. However, a new brain zapping therapy trialled by neuroscientists at University College, London has enabled patients to make a startling recovery, compared to patients undergoing traditional therapy.
Whilst patients were undergoing vocabulary training neuroscientist Jenny Crinion and her colleagues applied transcranial direct current stimulation to the left side of the brain in the area related to speech production. After six weeks the patients had improved by an astonishing 92%, compared to just 56% in patients who had received the vocabulary training without the stimulation therapy. The stimulation is thought to stimulate nerve cell activity in Broca’s area, which is the part of the brain devoted to speech comprehension and production.
For more information about stroke and how to recognise the signs click here.
March 5, 2012
Women who do not attend for cervical screening have only a 66% cure rate for cervical cancer, according to research published in the British Medical Journal this week. Not attending screening appointments means that women do not seek medical advice until symptoms of cervical cancer are being experienced. Symptoms of cervical cancer include abnormal bleeding, pelvic pain, unusual heavy discharge, pain after urination and bleeding after intercourse, and can easily be mistakenly attributed to other illnesses.
The Swedish Centre for Research and Development followed all 1230 women who were diagnosed with cervical cancer in Sweden between 1999 and 2001 to see just how significant smear tests are in cure rates. Sadly, 373 of the women died from cervical cancer and three quarters of them had one thing in common: they had not had a cervical smear in the recommended time frame.
For women diagnosed through screening the cure rate is 92% and the chances of a cure are higher for women who attend an appointment through invitation and are not overdue for a smear test. The NHS recommend that women between the ages of 25-49 be screened every three years and women over 50 every five years. You should be sent a letter telling you when your screening is due and if you think you are overdue, contact your GP to check.
The research shows that cervical screening within the recommended time frame substantially reduces the risk of cervical cancer and improves cure rates. You should make every effort to attend your appointment.