Addison's Disease (also known as adrenal insufficiency) is a dangerous affection of the renal capsules characterised by deep bronzing of the skin, anaemia, and extreme weakness. It was first described by Thomas Addison in 1855. Research Addison's Disease
Anaemia is the medical condition of lacking red blood cells or haemoglobin or both. I anaemic conditions the blood can carry less oxygen round the body, and is slower in removing the waste substances such as carbon dioxide from the tissues and organs. Research Anaemia
Ancylostomiasis (ankylostomiasis, anchylostomiasis) popularly known as hookworm disease, is an infestation of the human intestine by blood-sucking hookworms that causes progressive anaemia. Research Ancylostomiasis
Ankylostomiasis is a 'worm disease' to which miners are subject in some localities, is caused by vast numbers of small parasitic worms (Ankylostoma or Anchylostoma duodenale) in the duodenum or upper portions of the intestinal canal. Deriving their sustenance from the system, these worms produce anaemia or bloodlessness (that is, deficiency of the red corpuscles of the blood), the sufferers being pallid, feeble, short-breathed, liable to faint, and unequal to any laborious work, and death may result if a cure is not effected. Fortunately the disease is not difficult to cure using remedies which expell the worms from the system.
The disease is said to be common in tropical and sub-tropical countries all over the world. In Europe it was perhaps first observed in 1879 in the case of workmen engaged in excavating the St Gothard tunnel. Since 1896 it has been well known in some of the German mines; and in 1903 it was detected among the miners engaged in the Dolcoath mine in Cornwall. The eggs of the worms are carried from the body with the fasces; under favourable circumstances develop into larvae, which may gain entrance again into the human body by the mouth (perhaps in drinking-water), to attain full development in the intestine. Careful sanitary arrangements are a preventive of the disease, which is also known as 'miner's worm', 'miner's anaemia', etc. Research Ankylostomiasis
Ascariasis is an infection caused by a parasitic worm, ascarsis lumbricoides. This parasite is a pale, cylindrical, tapered roundworm that grows to between fifteen and forty centimetres in length. It lives in the small intestine of its host. The infection is common worldwide, especially in the tropics. It affects 80% to 90% of the population in poorer countries where standards of public hygiene and sanitation are low. One or several worms may be present in the infection, but symptoms generally only appear when there is multiple infestation. The eggs of the worm are carried by the wind in drier climates. In most cases, however, they are transmitted through water, food, and hands. The eggs are swallowed via the mouth of the new host and then hatch into larvae in the small intestine. The larvae travel through the wall of the intestine and are carried by the lymphatic vessels and the bloodstream to the lungs, up the trachea, and are swallowed back to the small intestine where they mature in the jejunum.
The worms reach maturity about two months after ingestion. The adult worms release eggs which are passed out through faeces to be acquired by a new host and start the cycle over. The lifespan of the worm is under 18 months, however, female worms produce up to 200,000 eggs per day. The eggs can remain viable for months or years. The condition is diagnosed by the presence of the eggs in an infected person's faeces during microscopic examination. Light infestation generally causes no symptoms or may cause slight nausea. Early symptoms of the passage through the respiratory system include coughing, wheezing, and a slight fever. Heavy infestation of the parasites compete with the host for food, leading to malnutrition and anaemia. In children, migration of the worms to the liver, gall bladder, or peritoneal cavity may cause death. Research Ascariasis
azathioprine is a synthetic drug that suppresses the normal immune responses of the body and is administered orally during and after organ transplantation and also in certain types of anaemia and rheumatoid arthritis. It has the formula C9H7N7O2S. Research Azathioprine
The development of bed sores in a patient in hospital, is usually considered to indicate bad nursing. Bed sores occur from interruption of the nutrition of areas of skin where the blood supply has been impaired by pressure. Bed sores are almost inevitable in some patients. The very thin, the very heavy, the incantinent and those who through some injury to the spine have lost the sensation of the skin at these points are most likely to develop pressure sores. Common sites for bed sores are the sacral area and the heels. In patients with septic conditions, nutrition is impaired by prolonged fever and there is frequently anaemia. Their toxic condition renders them less likely to move about and the greatest care needs to be taken to prevent the development of these pressure ulcers. Frequent change of position and massage of pressure points with spirit followed by powder is the best method of prevention. Early post-operative mobilisation of all patients who are fit to get up has done much to prevent this distressing complaint.
In unconscious patients or those who have had some injury to the spinal cord, a large pressure sore can develop as soon as twelve hours after the injury or onset of the illness. A bed sore on the sacral area may even develop from the patient's position on the operating table during a long operation. Although pressure sores rarely develop over the scapulae or the elbows, these points are subject to soreness and require similar preventive treatment when a patient is washed. An ulcer may develop on the shin from the weight of the other leg, if the legs of an unconscious patient are left crossed. Research Bed Sores
Normal red blood cells are of four main groups in relation to their behaviour when mixed with bloodplasma (or serum) of another individual. Similarly the plasma (and serum) of each individual belongs to one of four groups. If cells of one group meet plasma of an 'incompatible' group, the cells stick together in blocks. These clumps obstruct blood vessels and may cause death. The interaction of the incompatible cells and plasma is called 'agglutination'. The provocative substance in the cells is called the agglutlnogen, while the defensive substance in the plasma is the agglutinin. A similar mechanism develops in relation to our immunity to infections by certain bacteria and viruses. In blood transfusion, the amount of plasma administered is small in relation to the large amount of plasma in the recipient's circulation. On the other hand, even a small quantity of cells given to a patient whose plasma will not tolerate that particular type of cell, will lead to clumping of the donor's cells in the recipient's blood vessels. The importance therefore lies in the cells of the donor and the plasma of the recipient.l Plasma and serum for this purpose are identical and the serum obtained when a small quantity of blood is allowed to clot is used for testing against the donor's red cells. In order to determine a patient's blood group, a small quantity of blood is obtained from a finger or ear prick and immediately mixed with citrate to prevent clotting; the cells are then tested against special serum of known groups. To obtain the patient's serum for cross-matching, 5 ml of blood is taken, by vein puncture, and allowed to clot.
The four common groups have been numbered variously. The Moss classification I, II, III, and IV was used extensively until the adoption of the International A, B, O classification, which describes the groups according to the presence or absence of the specific cell factors, which are of two types, A and B. Thus we have four blood groups in the international system. In the first of these, both cell factors are present but no serum factors. The serum factors are called anti-A and anti-B, and obviously the cellfactor A and the serum factor anti-A could not exist in the same person. The second group contains cellfactor A and serum factor anti-B. The third group contains cellfactor B with serum factor anti-A, and the fourth group contains neither cellfactor but both serum factors. The fourth group could therefore be given to any of the other groups and the cells, having no clumping factors, would be tolerated in any recipient. On the other hand, the first group with both cell factors could not be given to any other group. The terms universal donor, Group O (MossIV), and universal recipient, Group AB (MossI), were used to amplify the earlier grouping system. Transfusion with the wrong group of blood is usually fatal so that very great care has to be taken in the determination of the blood group, both of donor and recipient.
Since the 1950s hitherto unexplained incompatability was found to be due to the presence of other factors than the A, B, O, agglutinogens. The most important of these is the rhesus cellfactor. Certain monkeys (Rhesus species) have this factor naturally, but it is present in only 85 per cent of white people in England and America. The other 15 per cent - Rh negative - may become sensitized to Rh positive cells by repeated transfusion of Rh positive blood. A rhesus negative mother whose husband is ph positive may produce an Rh positive baby. A battle occurs between the unborn baby's cells and the mother's plasma. The baby may die before birth (miscarriage) or be born with very severe anaemia and jaundice. If born alive, the baby is treated by complete replacement of its blood to get rid of the mother' s sensitized Rh negative plasma. This is 'exsanguination-transfusion'. During the 1950s blood grouping in preparation for transfusion became a complex and very responsible task. In most hospitals it is undertaken by specialists - perhaps a pathologist or transfusion officer. During the 1980s as HIV paranoia spread, even more testing started to be done. Research Blood Groups
The transfer of blood from one individual to another first became a practical proposition during the Great War. The recognition of four major blood groups indicated that there were limitations on blood transfusion which necessitated very careful examination of the blood of the two individuals concerned. In the early days of transfusion after preliminary grouping, the blood was transferred from the donor to the recipient by the ' direct' method, using a two-way tap and syringe, so that the blood was not exposed to the air and had no opportunity for clotting. The 'indirect' method was later introduced in which the donor's blood was received into a solution of sodium citrate which prevented it from clotting by inactivating the calcium. Within an hour or so the blood was then injected into the veins of the recipient. Prior to the second World War, most large hospital centres in Great Britain maintained a panel of blood donors who were willing to come to the hospital at any hour of the day or night for emergency transfusion. The relatives of patients also were called upon, if with the right blood group, to give their blood.
The necessities of war, and the greater demands of surgery for blood transfusion led to the establishment of ' blood banks', in which are stored large quantities of blood taken at a convenient time from thousands of volunteers. With suitable refrigeration, blood may be stored for three weeks with safety and such blood is quite suitable for the treatment of shock and conditions of blood loss. Certain other disorders, mainly medical conditions affecting the formation of red cells in the bonemarrow, are preferably treated with the transfusion of fresh blood: this seems to possess properties which become lost in storage. Blood transfusion performs a double purpose. It replaces the oxygen-carrying red cells and its fluidfraction, the plasma, contributes protein which maintains the circulating blood volume, thus preventing the escape of water into the tissues. Plasma or serum may be separated from the whole blood and dried. In this form it was used extensively during the Second World War because it could be stored indefinitely and could be reconstituted by the addition of distilled water when infusion was needed in the treatment of shock. By the extraction of the fluid portion of the whole blood, the cell content may be concentrated. Such a preparation is known as packed cells. This has become of particular value if it is necessary to raise the haemoglobin rapidly without raising the blood volume unduly. Such a procedure may be required in the treatment of severe anaemia arising from toxaemia. Research Blood Transfusion
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Gallsickness
