An ELISA test uses components of the immune system and chemicals to detect immune responses in the body (for example, to infectious microbes). The ELISA test involves an enzyme (a protein that catalyzes a biochemical reaction). It also involves an antibody or antigen (immunologic molecules).
ELISA tests are widely utilized to detect substances that have antigenic properties, primarily proteins (as opposed to small molecules and ions such as glucose and potassium). The substances detected by ELISA tests include hormones, bacterial antigens and antibodies.
There are variations of the ELISA test, but the most basic type consists of an antibody attached to a solid surface. This antibody has affinity for (will latch on to) the substance of interest, for example, human chorionic gonadotropin (HCG), the commonly measured protein which indicates pregnancy. A mixture of purified HCG linked (coupled) to an enzyme and the test sample (blood, urine, etc) are added to the test system. If no HCG is present in the test sample, then only HCG with linked enzyme will bind. The more HCG which is present in the test sample, the less enzyme linked HCG will bind. The substance the enzyme acts on is then added, and the amount of product measured in some way, such as a change in color of the solution.
ELISA tests are generally relatively accurate tests. They are considered highly sensitive and specific and compare favorably with other methods used to detect substances in the body, such as radioimmune assay (RIA) tests. They have the added advantages of not needing radioisotopes (radioactive substances) or a costly radiation counter (a radiation-counting apparatus).
There are many symptoms involved in the 1st, 2nd and 3rd trimesters of pregnancy. The first early pregnancy symptom is typically a missed period, but others include breast swelling and tenderness, nausea and sometimes vomiting, fatigue and bloating. Second trimester symptoms include backache, weight gain, itching, and possible stretch marks. Third trimester symptoms are additional weight gain, heartburn, hemorrhoids, swelling of the ankles, fingers, and face, breast tenderness, and trouble sleeping. Read more to learn about recommended procedures and tests for each stage of a healthy pregnancy.
Hypothyroidism is any state in which thyroid hormone production is below normal. Normally, the
rate of thyroid hormone production is controlled by the brain at the pituitary.
Hypothyroidism is a very common condition and the symptoms of hypothyroidism are
often subtle.
HIV (human immunodeficiency virus) is the cause of AIDS (acquired immunodeficiency syndrome). HIV is a type of virus called a retrovirus, which infects humans when it comes in contact with a break in the skin or tissues such as those that line the vagina, anal area, mouth, or eyes.
Lyme disease is a bacterial illness, which is spread by ticks when they bite the skin. Initially the disease affects the skin causing a reddish rash associated with flu-like symptoms. It takes weeks to months after the initial redness of the skin for its effects to spread throughout the body. Lyme disease can be treated with antibiotics. Lyme disease can be prevented by using tick avoidance techniques.
Hyperthyroidism is an excess of thyroid hormone resulting from an overactive thyroid gland. Symptoms can include increased heart rate, weight
loss, depression, and cognitive slowing. Treatment is by medication, the use of
radioactive iodine, thyroid surgery, or reducing the dose of thyroid hormone.
The most common food allergies are to eggs, nuts, milk, peanuts, fish, shellfish, strawberries and tomatoes. Symptoms and signs include nausea, vomiting, diarrhea, abdominal pain, itching, hives, eczema, asthma, lightheadedness, and anaphylaxis. Allergy skin tests, RAST, and ELISA tests may be used to diagnose a food allergy. Though dietary avoidance may be sufficient treatment for mild allergies, the use of an Epipen may be necessary for severe food allergies.
An allergy refers to a misguided reaction by our immune system in response to bodily contact with certain foreign substances. When these allergens come in contact with the body, it causes the immune system to develop an allergic reaction in people who are allergic to it. It is estimated that 50 million North Americans are affected by allergic conditions. The parts of the body that are prone to react to allergies include the eyes, nose, lungs, skin, and stomach. Common allergic disorders include hay fever, asthma, allergic eyes, allergic eczema, hives, and allergic shock.
Pregnancy planning is important to help prevent exposure of the mother and fetus to potentially harmful medications and substances during the early days, and throughout the pregnancy. Nutritional planning, prevention of birth defects, conditions such as high blood pressure, heart disease, diabetes, and kidney disease need careful monitoring. Gestational diabetes, preeclampsia, and pregnancy induced hypertension are conditions that may arise during pregnancy. Immunizations, inherited disorders, exercise, air travel, intercourse, and birth control are important factors to consider when planning a pregnancy.
Leishmaniasis is a disease caused by the bite of an infected sand fly. The most common types of leishmania infection are cutaneous and visceral leishmaniasis. Leishmaniasis is found mainly in the subtropics and tropics. Symptoms and signs of cutaneous leishmaniasis include skin sores with a raised edge and central crater, while those with visceral leishmaniasis usually have fever, weight loss, and an enlarged liver and spleen.
Chagas disease is an infection caused by the T. cruzi parasite. Symptoms of Chagas disease include rash, swollen lymph nodes, fever, fatigue, nausea, vomiting, and the Romaña sign. An ELISA test is used to diagnose Chagas disease. Treatment depends upon the phase of the disease and the patient's age.
Rocky Mountain spotted fever (RMSF) is an infectious disease that's transmitted by the bite of a tick infected with the Rickettsia rickettsii bacterial organism. Initial symptoms of RMSF include fever, nausea, vomiting, muscle pain and severe headache. Later symptoms include rash, abdominal pain, joint pain, and diarrhea. Treatment usually involves a tetracycline antibiotic.
Monkeypox is a viral disease that causes symptoms such as fever, sweating, and a rash with papules and pustules on the face and chest. PCR, ELISA, or Western blot tests are used to diagnose monkeypox. Treatment usually involves administering a smallpox vaccination, cidofovir, and possibly vaccinia immune globulin.
Disease prevention in women includes screening tests that are a basic part of prevention medicine. All screening tests
are commonly available through your general doctor. Some specialized tests may be available elsewhere.
Hyperthyroidism is a condition in which an overactive thyroid gland is producing an excessive amount of
thyroid hormones
that circulate in the
blood. ("Hyper" means "over" in Greek). Thyrotoxicosis is a toxic condition that is caused by
an excess of thyroid hormones from any cause. Thyrotoxicosis can be caused by
an excessive intake of thyroid hormone or by overproduction of thyroid hormones by the thyroid gland. Because both physicians and patients
often use these words interchangeably, we will take some liberty by using the
term "hyperthyroidism" throughout this article.
What are thyroid hormones?
Thyroid hormones stimulate the metabolism of cells. They are produced by the
thyroid gland. The thyroid gland is located in the lower part of the neck, below the Adam's apple. The gland wraps around the
windpipe (trachea) and has a shape that is similar to a butterfly formed by two
wings (lobe...