Excreta Health Dictionary

A group of viruses that infect mice, rats and voles and can also infect humans who come into contact with the excreta or secretions of these animals. Widely distributed in Asia, the USA and Europe, in Britain hantavirus usually affects rural and sewage workers, as well as people engaged in watersports. Many victims have a mild feverish illness; severe cases are characterised by headache, high temperature, nausea, vomiting and even shock, accompanied by skin PETECHIAE. The kidneys and sometimes the lungs are affected, and in severely affected patients mortality is high.... hantavirus

This is a form of a chemical element with the same chemical properties as other forms, but which has a di?erent atomic mass. It contains an identical number of positively charged particles called protons, in the nucleus, giving it the same atomic number, but the numbers of neutrons di?er. A radioactive isotope, or radionuclide, is one that decays into other isotopes, and in doing so emits alpha, beta or gamma radiation.

Applications of radionuclides to diagnosis The use of radionuclides in diagnosis is based on the fact that it is possible to tag many of the substances normally present in the body with a radioactive label. Certain synthetic radioactive elements, such as technetium, can also be used. Because it is possible to detect minute quantities of radioactive material, only very small doses are needed, making the procedure a safe one. Furthermore the body pool of the material is therefore not appreciably altered, and metabolism is not disturbed. Thus in studies of iodine metabolism the ratio of radioactive atoms administered to stable atoms in the body pool is of the order of 1:1,000 million. By measuring radioactivity in the body, in blood samples, or in the excreta it is possible to gain information about the fate of the labelled substance, and hence of the chemically identical inactive material. Therefore it is theoretically possible to trace the absorption, distribution and excretion of any substance normally present in the body, provided that it can be tagged with a suitable radioactive label.

If the investigation necessitates tracing the path of the material through the body by means of external counting over the body surface, it is obviously essential to use an isotope that emits gamma radiation or positrons. If, however, only measurements on blood sample or excreta are required, it is possible to use pure beta emitters. Whole-body counters measure the total radioactivity in the body, and these are of great value in absorption studies.

Moving images can provide information on body functions such as the movements of the heart, blood ?ow, bile ?ow in the liver, and urine in the kidneys. The development of COMPUTED TOMOGRAPHY or CT scanning has replaced radionuclide scanning for some imaging procedures.

Five main groups of diagnostic uses may be de?ned:

(1) METABOLIC STUDIES The use of radioactive materials in metabolic studies is based on the fundamental property that all isotopes of an element are chemically identical. The radioactive isotope is used as a true isotope tracer – that is, when introduced into the body (in whatever form) it behaves in the same way as the inactive element. For example, isotopes of iodine are used to measure thyroid function (see THYROID GLAND), and isotopes of calcium enable kinetic studies of bone formation and destruction to be performed.... isotope

These are waste products or metabolites of nucleoproteins. They are not recyclable and are broken down further to the primary excretable form, uric acid. High purine presence in a tissue signifies a recent high turnover in nucleoproteins from injury or cell death, which is why some purines, such as allantoin, will stimulate cell regeneration. Many plants contain allantoin, most noticeably Comfrey. Some foods are heavy purine producers and can elevate serum uric acid levels. These include organ meats, seafood, legumes, and such politically correct foods as spirulina, chlorella, and bee pollen. Caffeine and theobromine are purine-based alkaloids and can mildly increase uric acid, but they pale beside algae, pollen, and glandular extracts from the chiropractor.... purines

An infection caused by the amoeba ENTAMOEBA HISTOLYTICA, a tiny single-celled parasite that lives in the human large intestine. Amoebiasis is spread through drinking water or eating food contaminated by human excreta containing cysts of the amoeba.

Some people carry the amoeba in their intestines and excrete cysts but have no symptoms.

However, some strains invade and ulcerate the intestinal wall, causing diarrhoea and abdominal pain, which may develop into full-blown dysentery.

The amoebae may spread via the bloodstream to the liver, or, rarely, the brain or lung, where they cause abscesses.

Symptoms of an amoebic liver abscess are chills, fever, weight loss, and painful enlargement of the liver.

Treatment of all forms of amoebiasis is with drugs such as metronidazole or diloxanide, which kill the parasite within a few weeks, leading to full recovery.... amoebiasis

n. (pl. miracidia) the first-stage larva of a parasitic *fluke. Miracidia hatch from eggs released into water with the host’s excreta. They have *cilia and swim about until they reach a snail. The miracidia then bore into the snail’s soft tissues and there continue their development as *sporocysts.... miracidium

a large non-bloodsucking fly, Cordylobia anthropophaga, widely distributed in tropical Africa. The female fly lays its eggs on ground contaminated with urine or excreta or on clothing tainted with sweat or urine. The maggots are normally parasites of rats, but if they come into contact with humans they penetrate the skin, producing boil-like swellings (see also myiasis). The maggots can be gently eased out by applying oil to the swellings.... tumbu fly