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| HEALTH TRIBUNE | Wednesday, September 18, 2002, Chandigarh, India |
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Biochemical markers in coronary artery disease The bronchial problems New refined insulin
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Biochemical markers in coronary artery disease Heart is a muscular organ responsible for pumping blood to all parts of the body efficiently. During an average human life span of 75 years, the human heart contracts approximately 3x109 times. However, heart failure can and does occur. There are many causes for heart
failure but coronary artery disease (CAD) is the leading cause. CAD is defined as impairment of the heart function due to inadequate blood flow to the heart compared to its needs, caused by obstructive changes in the blood vessels supplying heart muscle and is responsible for 25-30 per cent deaths in most industrialised countries. It is a “modern epidemic” and several risk factors are associated with this disease. Some of the risk factors are modifiable like cigarette smoking, hypertension, evevated serum cholesterol, diabetes mellitus, obesity, sedentary habits and stress while others are non-modifiable — age, sex, family history, genetic factors and personality. These factors place an individual in high-risk category for developing CAD. Serum cholesterol is a significant biochemical marker for developing CAD as elevated serum cholesterol levels enhance atherosclerotic process (fat deposition in blood vessels). When fat is deposited in blood vessels supplying heart muscles, it damages the muscles by obstructing the blood flow leading to a condition known as myocardial infarction (MI). Further, hypertension accelerates the atherosclerotic process too. Elevated levels of blood lipoproteins (lipids associated with proteins) like low density lipoproteins (LDL) and decreased high-density lipoproteins (HDL) have direct association with CAD. These lipoproteins are responsible for the deposition of fat in blood vessels thereby hampering the flow of blood to tissues. Lipoproteins like Apo(a) and small dense LDL are better predictors of CAD. In recent years, homocysteine (an amino acid) has been identified as an independent risk factor for CAD. Because of its importance, it has been aptly called the “new cholesterol”. Hyperhomocysteinemia produces two major effects. Firstly, it favours the clotting of blood thereby enhancing the risk of blood vessel blockages. Secondly, it favours the formation of oxidized-LDL, which in turn accelerates atherosclerosis. Hyperhomocysteinemia may be genetic or it could be acquired as happens in the case of deficieny of B-complex vitamins, low levels of thyroid hormones, kidney disease and psoriasis. As many as 20 per cent of patients with CAD have concurrent hyperhomocysteinemia. A few known serum proteins are released into blood in large quantities from damaged heart muscles after myocardial infarction (MI) and these are referred to as cardiac markers. The most valuable diagnostic serum cardiac markers are CK-MB (Greatinine kinase — MB isoform) and Troponins (Tn-T, Tn-I). CK-MB rises within 48 hours and generally returns to normal by 48-72 hours. The MB isozyme has an advantage over total CK as it is not present in significant concentration in extra cardiac tissues and is more specific. Serial measurement of CK-MB is comparatively better to reach at exact diagnosis of MI. Cardiac troponins are better diagnostic biological markers than CK-MB. Troponins unlike CK-MB are normally not detectable in the blood of healthy individuals but may increase to levels over 20 times than normal in acute myocardial infarction and hence are the preferred cardiac markers for MI. Cardiac troponins can distinguish even small MI or skeletal muscle injuries undeteched by CK-MB measurement. Levels of cardiac troponins may remain elevated for up to 10-14 days and hence have replaced the measurement of lactate dehydrogenase (LDH) and its isoenzyme in patients suspected of MI. LDH, especially the LDH1 isozyme, used to be one of the significant cardiac markers for diagnosing MI in patients coming 24-48 hours after the onset of the symptoms (when the initial CK-MB) elevation might have been missed) but being less cardiac specific is not in use now. Serum 2-hydroxy butyrate dehydrogenase (SHBD) is a more sensitive index of MI showing a similar profile as LDH but remains elevated even after 16-18 days, which is obsolete now. If the Tn level remains elevated for more than 1 wk it indicates recurrent MI. Myoglobin is a muscle protein, which gets released into blood after muscle damage (both cardiac/skeletal) and is released into blood within only a few hours of the onset AMI. Although myoglobin is one of the first serum markers that rises above the normal range, it lacks cardiac specificity and is excreted out in urine, so that blood-level returns to normal within 24 hours of the onset of infarction. Generally, patients of MI are not able to reach the hospital in early hours of attack and many patients even miss it hence, serial measurement of serum cardiac markers specifically troponins can lead to exact diagnosis. Moreover, 15-20 per cent cases in MI are painless (e.g. in some diabetic patients and the cardiac markers are essential in making the differential diagnosis. Thus, serum cardiac markers have a significant diagnostic role in assessing coronary artery disease. The writer is Head, Department of Biochemistry, PGI, Chandigarh.
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The bronchial problems Inflammation of the bronchial tubes may be acute or chronic. The acute variety is more common in children as a complication in wooping cough, measles and other acute affections may occur even without any connection with other diseases. Malnutrition, unhygienic surroundings and habits may act as predisposing factors while exposure to cold, wet weather and extension of nasal catarrh may serve as exciting causes. The attack ushers in with nasal catarrh and cough with scanty, frothy expectoration at first which soon becomes abundant. The temperature is not very high, and there is difficulty in respiration. The breathing is rattling and wheezing as the air has to pass through the mucus in the bronchi. The type described above is the mild one which affects only the wind pipe (trachea) and the larger bronchi. When the smaller bronchioles are affected, the condition is serious. The is met with in connection with influenza, measles or any other such acute complaints and leads to pneumonia. There is dyspnoea, quick pulse, temperature ranging between 102 and 104. The disease generally runs a course of 14 days in severe cases. Prognosis is bad in the extremeties of age due to defective resistance. If acture bronchitis does not begin to clear up within two or three weeks, phthisis may be suspected. Treatment: Keep the patient away from draughts, but in a well-ventilated room. Keep him away from the exciting causes. Inhalation of steam may do good in some cases. After he is cured, breathing exercises should be taken in a graduated form so as to prevent a relapse. Begin the treatment with a few doses of Aconite-30 every three hours in the acute type. After 24 hours of the administration of Acon, stop Aconite and give any of the following according to indications. Antim Tart, Ferr, Phos, Ipec, Bry, etc. Any remedy which is indicated in cough may be indicated in bronchitis, especially the chronic type. The writer is a practising homoeopath based in Chandigarh.
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New refined insulin Melbourne People with diabetes may only need a third of their usual dose when taking the new form of insulin, a team of Australian scientists has shown. It is made up of tiny particles under 100 nanometres (100 millionths of a millimetre) across. In tests on rats conducted at Deakin University, near Melbourne, 0.15 units per kilogram of body weight produced the same response as 0.5 units of normal insulin. The study did not set out to establish a minimum dose, and experts believe the new insulin may be more than three times as potent as the traditional form. The new drug also produced a more sustained effect, New Scientist magazine reported.
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INFO CAPSULE Tobacco, travel & asthma problems Washington The study, published in Chest, examined 374 non-smoking adults with asthma who lived in California. The authors said that the state prohibits smoking at workplaces and most other public areas. That means travel is the main source of ETS for non-smokers who don't live with a smoker. ANI Stomach cancer Sydney In experiments on mice, Dr Matthias Ernst from the Ludwig Institute for Cancer Research in Melbourne and Associate Professor Andy Giraud from the University of Melbourne (Western Hospital) made specific mutations to a molecule found on the surface of cells that is traditionally involved in helping regulate the body's immune system.
ANI Restricted diet’s role Washington Now, a 14-year-long US study of canine diet and health, partial results of which were published in the May issue of the Journal of the American Veterinary Medical Association, has only added to this growing body of evidence.
ANI For dying patients Toronto The researchers said their recommendations clarify the blurry lines between euthanasia, which is illegal in all countries except the Netherlands, and good medical care for dying people who are in pain. The study’s guidelines could spark controversy with groups opposed to euthanasia who say they’re concerned that doctors might take the recommendations of the study too loosely.
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