It's Not Just The Sun: DeCODE Discovers Sequence Variants Affecting Susceptibility To Skin Cancer
Scientists at deCODE genetics (Nasdaq: DCGN) and academic colleagues from Europe and the United States today present in the journal Nature Genetics the discovery of common genetic risk factors for basal cell carcinoma (BCC) that affect people with fair and dark complexions alike. deCODE had previously discovered five common single-letter variants in the sequence of the human genome (SNPs) linked to risk of BCC, the most common cancer in people of European descent. However, most of these earlier findings were also correlated with fair skin, well known to accompany vulnerability to the damaging effects of ultraviolet radiation in sunlight.
Cardiovascular
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What Is Low Blood Pressure? What Is Hypotension?
these heart problems tend to result in serious hypotension. How is low blood pressure (hypotension) diagnosed? The doctor will try to establish whether there is an underlying cause. This will help decide on the best treatment. A nervous disease problem will not have the same treatment as, for example, a heart problem. The doctor may order some of the following tests: Sphygmomanometer - to measure blood pressure Most lay people have seen this device. It consists of an inflatable cuff that is wrapped around the upper arm. When the cuff is inflated it restricts the blood flow. A mercury or mechanical manometer measures the pressure. A sphygmomanometer is always used together with a means to determine at what pressure blood flow is just starting, and at what pressure it is unimpeded. For example, a manual sphygmomanometer is used together with a stethoscope. *The cuff is placed snugly and smoothly around the upper arm, at approximately the same altitude as the heart while the patient is sitting up with the arm supported (resting on something). It is crucial that the size of the cuff is appropriate. If it is too small the reading will be inaccurately high; if it is too large the reading will be too low. *The cuff is inflated until the artery is completely obstructed (occluded). *The nurse, doctor, or whoever is doing the examination listens with a stethoscope to the brachial artery at the elbow and slowly releases the cuff"s pressure (deflates it). *As the cuffs pressure falls the examiner will hear a whooshing sound or a pounding sound when blood flow starts again. *The pressure at the point when the sound began is noted down and recorded as the systolic blood pressure. *The cuff is deflated further until no sound can be heard. At this point the examiner notes down and records the diastolic blood pressure. With a digital sphygmomanometer everything is done with electrical sensors. To find out whether the problem is a sustained one, diagnosis confirmation requires more than one reading. Blood tests These may indicate whether there are any problems with high sugar (hyperglycemia) or low sugar (hypoglycemia) levels. A low red blood cell count would indicate anemia. ECG (electrocardiogram) This device detects heart rhythm irregularities, problems with blood supply to heart muscles, as well as any structural abnormalities in the heart. It can also determine whether the patient ever had a heart attack, or is even having one while the test is underway. Holter monitor This is a sort of portable ECG device. If the ECG does not detect any problems the doctor may want to monitor the patient"s heart rhythm for longer, perhaps for a 24 hour period. The patient wears the Holter monitor which records the heart"s electrical activity as he/she goes about his/her daily business. The device is worn in a pouch either around the waist or neck. The doctor may ask the patient to record their activities and any symptoms they may feel into a diary. The details of the diary, which should include specific times, will be compared to the Holter"s records. Echocardiogram This device uses ultrasound waves which show the heart in motion. The doctor will be able to detect problems, such as defective heart valves. Exercise stress test An exercise stress test sometimes reveals problems that are not apparent when the body is resting. The stress test assesses how the body"s cardiovascular system responds to increased physical activity. The test monitors the electrical activity of the heart, as well as the patient"s blood pressure during exercise. Imaging scans of the heart"s blood supply might be done at the same time. Valsalva maneuver This tests the functioning of the autonomic nervous system. After several cycles of a type of deep breathing it analyses the heart rate and blood pressure. The patient takes a deep breath and then tries to blow out with the mouth closed and the nose blocked (so no air can get out). Tilt-table test If you have postural hypotension (low blood pressure when standing from a sitting/lying position), or neurally mediated hypotension (low blood pressure from faulty brain signals) and neither the ECG nor the Holter revealed anything, a tilt-table test may be performed. This monitors blood pressure, heart rhythm and heart rate while the patient is moved from a lying down to an upright position. Our reflexes cause the heart rate and blood pressure to change when moved to an upright position - this is to make sure the brain gets an adequate supply of blood. If the reflexes are inadequate, they could explain some of the symptoms, such as the fainting spells. What is the treatment for low blood pressure (hypotension)? People with hypotension and either no symptoms or very mild ones do not require treatment. The National Health Service (NHS), UK, says that a very small percentage of patients who are diagnosed with low blood pressure by their GPs (general practitioners, primary care physicians) are prescribed medications. *Medication for low blood pressure Some elderly patients who experience symptoms when they suddenly stand up (postural hypotension) may be prescribed medication to narrow the arteries. Fludrocortisones helps boost blood volume. Midodrine also helps boost blood pressure levels. *Low blood pressure caused by medications If the doctor believes the low blood pressure is being caused by a medication, the dose may be altered. If possible, the doctor may prescribe another medication. If the patient is on a blood pressure lowering drug, such as doxazosin, or an alpha blocker and becomes dizzy or faints when standing up, the doctor will need to find out whether it is being caused by a drop in blood pressure. If it is, the medication will need to be changed. *Underlying illnesses or conditions If the General Practitioner believes the hypotension is being caused by an underlying condition or illness, such as adrenal gland failure, a thyroid disorder, a nerve condition or a heart condition, the patient will most likely be referred to a specialist. *Adrenal gland failure This is treated by replacing the missing hormone, aldosterone. *A nerve condition This is usually harder to treat. The patient may be given medication to stimulate the nervous system. *Salt and fluids Increasing salt intake may improve the symptoms of hypotension, especially for those with postural hypotension. This can be done either by taking salt tablets or adding more salt to food. It is important to make sure your fluid intake is adequate - ask your doctor how much fluid (water) you should ideally consume each day. Fluids increase blood volume and prevent dehydration - both have an impact on blood pressure levels. *Compression stockings These help stimulate circulation. What are the complications of hypotension (low blood pressure)? *Orthostatic hypotension (postural hypotension) In most cases becoming slightly dizzy or woozy when you stand up is just a nuisance, and nothing more. However, if it causes a severe drop in blood pressure there is a risk of injury if you faint and fall down. If sitting and then standing and then sitting, etc., cause large fluctuations in blood pressure there is also a higher risk of developing stroke, dementia, and other brain disorders. *Severe hypotension Untreated severe low blood pressure can in the long-term damage the organs, including the heart and the brain. Written by Christian Nordqvist Copyright: Medical News Today Not to be reproduced without permission of Medical News TodayPages: 1 [2]