3 Lymphatic & Immune System Terms

Frank LemondBiology 120

6/27/10

I. ELISA

I. ELISA

• ELISA, aka an enzyme immunoassay, or EIA, aka enzyme-linked immunosorbent assay, = a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample. (An antibody = a protein material made in the body as a response to the invasion of a foreign substance. An antigen = a foreign invader that stimulates an immune response). ELISA has been used as a diagnostic tool in medicine & for plant diseases, and also as a quality-control check in some industries. In ELISA, an unknown amount of antigen = attached to a surface, and then a certain antibody = applied over the surface so that it’ll bind to the antigen.

I. ELISA (cont’d)

• This antibody = linked to an enzyme, (protein that increases the rate of a chemical reaction) & in the final step a substance = added that the enzyme can convert to some detectable signal. For example, in the case of fluorescence ELISA, when light of the right wavelength = shone on a sample, any antigen and/or antibody complexes will fluoresce so that the amount of antigen in the sample can be inferred through the strength of the fluorescence.

• ELISA = a useful tool in checking serum antibody concentrations (such as the HIV test or West Nile Virus).

II. HIVES

II. HIVES• Hives are raised, often itchy, red welts on the epidermis. They’re

usually an allergic (hypersensitive) reaction to medicine or food. • The symptoms of hives include:• 1. Swelling of the epidermis (surface of the skin) into skin-colored or

red welts (wheals) with clearly-defined edges.• 2. Itching.• The wheals may enlarge, spread, and join together to form larger

areas of flat, raised skin. • They can also change shape, disappear, and reappear within hours or

minutes .• The wheals tend to start suddenly and go away quickly. When one

presses the center of a red welt, it turns white. This = aka blanching.

II. HIVES (cont’d)

• Treatment may or may not be needed if the hives are mild. They can disappear on their own. To reduce swelling & itching:

• AVOID HOT baths or showers.• Avoid irritating the area(s) with tight-fitting clothes.• Take antihistamines (substances that act to control

allergic symptoms by counteracting histamine, which = in the body & = released in allergic reactions).

II. HIVES (cont’d).

• When one has an allergic reaction to a substance, the body releases histamines + other chemicals into the blood. This causes swelling, itching, + other symptoms. Hives are a common reaction, esp. in those with other allergies such as hay fever.

• Many substances can trigger hives, such as:• 1. Cat dander (or other animal dander)• 2. Insect bites• 3. Certain medications• 4. Pollen• 5. Foods, such as milk, eggs, peanut butter, nuts, shellfish, fish,

etc.

III. NOSOCOMIAL INFECTIONS

III. NOSOCOMIAL INFECTION• Nosocomial infections are infections that are a result of treatment

in a healthcare service unit such as a nursing home or hospital. These infections are considered nosocomial if they first appear 2 days or more after hospital admission or within 30 days after discharge. In the US, the CDC (Centers for Disease Control & Prevention) estimated that approx. 1,700,000 hospital-associated infections, from all types of bacteria combined, cause or contribute to 99,000 deaths/year.

• Nosocomial comes from the Greek word nosokomeion (hospital) (nosos = disease, komeo = to take care of).

• Nosocomial infections are often transmitted when hospital workers become complacent & personnel don’t practice hygiene regularly.

III. NOSOCOMIAL INFECTION (cont’d).

• Also, increased use of outpatient treatment means that people who are hospitalized are more ill & have more weakened immune systems than may have been true before.

• Hospitals have sanitation rules regarding uniforms, equipment sterilization, washing, & other measures. Complete hand-washing and/or use of alcohol wipes by all medical personnel before + after each patient contact = a very effective way to fight nosocomial infections.