Kristen Magliola 12/1/13 BIO 414 Allergies When foreign antigens possess structures similar to host structures, the immune system can be tricked into attacking itself. This problem is otherwise known as an allergic hypersensitive reaction. The antigen that causes the reaction is called an allergen. So altogether allergies are caused by allergens. There are four different types of allergic/ hypersensitivity reactions. They include: Type II, III hypersensitivity, and I. Last but not least Type IV is cell- mediated hypersensitive. Type I hypersensitivity is otherwise known as IgE mediated hypersensitivity. It usually takes about 2-30 min for the reaction to occur and the host has to be exposed to the allergen twice. This kind of sensitivity can also be referred to as immediate or anaphylactic hypersensitivity. This reaction is usually the most common and it occurs due to excess IgE targeting the antigen. The skin, eyes, nasopharynx(nose) bronco pulmonary tissues( lungs/ asthma) and gastrointestinal tract are usually involved. For example when an individual is exposed (ie bee sting allergy) the smooth muscle contracts and the capillaries dilate due to the release of pharmacologically active substances. To break it down even further the primary cellular component in this hypersensitivity is the mast cell or basophil. The reactions are then amplified by platelets, neutrophils and eosinophils. Altogether the mast cells are mostly made up of eosinohils. As stated above excess IgE is produced in response to the antigen so exposure to the same allergen cross links the cell bound IgE and triggers the release of active substances. This is important in triggering the basophil or mast cells. Basophil degranulation is preceded by increased calcium. Ionophores also promote degrnaulation. Agents that decrease cytoplasmic calcium suppress degranulation. There are also many mediators involved in immediate hypersensitivity. To name a few, they include histamine, tryptase, kininogenase, ECF-A, Leukotriene B-4, C4, D4, Prostoglandins D2, and PAF. Other stimuli such as exercise, stress, chemicals, and anaphylotoxins can also trigger mast cells. These reactions are not considered hypersensitive reactions because they are mediated by agents without a IgE allergen interaction. SO how do they work? They are amplified by platelet activation factors. This causes platelet aggregation and releases amines. These amines are: histamine, heparin, and vasoactive. Cyclic nucleotides also play a role in immediate hypersensitivity. Subtances which alter camp and cGMP levels alter allergic symptoms. Increasing cAMP relieves symptoms and vice versa. Treatment for immediate hypersensitivity includes antihistamines, leukotriene receptor blockers, chromolyn sodium, inhibitors of cyclooxygenase pathway, inhalers/ bronchodilators, Thophylline, and IgG antibodies against Fc potions of IgE. Type II hypersensitivity is otherwise known as cytotoxic hypersensitivity. It is also more severe than type I and takes 5-8 hrs to be initiated. In this case the organs and tissues are affected. Antibodies of IgM and IgG play a big role in this type of reaction. A typical example of type II hypersensitivity is a mismatched blood transfusion. In this case the interaction of antibodies and surface antigens of the cells are followed by complement-assisted lysis of these cells. To sum it up, in antibody-dependent cell-mediated cytotoxicity (ADCC), cells exhibiting the foreign antigen are tagged with antibodies (IgG or IgM) and they are then recognized by natural killer (NK) cells and macrophages, which in turn kill these tagged cells. Type III hypersensitivity is otherwise known as immune complex hypersensitivity. This type of reaction occurs when there is little antibody and an excess of antigen, leading to the formation of small immune complexes. This reaction usually takes 2-8 hrs to have results. In this case the Ag- Ab complexes are…
The Immune System
The immune system is the most incredible part of our body. It has the task of keeping the body healthy by destroying pathogens and disease-producing organisms, and by neutralizing their toxins. The immune system employs the services of the skin, mucous membranes, hair, cilia, saliva, urine and other natural means of waste disposal to keep the body free of illness and pathogens, For instance, should foreign bacteria enter the body, the immune system will employ cells in the…
airborne, waterborne, food, insects and animals
Pathogens cause disease by producing toxins and damaging cells.
This is a serious water borne and food borne bacterial infection
Sufferer suffers from dehydration and diarrhoea.
A toxic protein is released by the cholera bacteria into the small intestine.
Toxin damages the carrier proteins in the plasma membrane of the epithelial cells lining the small intestine.
This produces a large release of chloride ions into the gut lumen.
By researching stem cells scientists have suggested that too much SP2 protein may turn stem cells into cancer cells. Other issues thought to play a role in the spread of cancer include viruses, immune system issues, genetics, environment and age. However, a lack of particular co-stimulated molecules that aid in the way antigens react with lymphocytes can impair the natural killer cells ability and ultimately cause cancer.
All cancers begin in cells, the body's basic unit of life. To understand…
1. Discuss the structure and function of the normal cell belonging to the effected organ.
a) Name the cancer affected organ and what are the vital functions of that organ in the human body
The cancer affected organ in the body is the breast. Breasts are complex, specialized organs whose primary function is to produce milk for an infant or a baby.
b) Specialised tissues that the organ is made up of
The structure of the female breast is complex — including fat and connective…
immunodeficiency disorders. It is a group of congenital disorders in which the humoral part of the patient’s immune system and cells involved in immune responses fail to work properly. Children with this horrible disorder are vulnerable to infections, retarded growth, and early death.
SCID is thought to affect between one in every 100,000 persons, and one in every 500,000 infants. Several different immune system disorders are currently grouped under SCID:
Adenosine deaminase deficiency…
information. Can be either single-stranded or double stranded DNA or RNA
capsid= protein coat which surrounds and protects genome
envelope= membrane (phospholipid bilayer) which surrounds the capsid.
Highly specific for organism it infects
To make new copies of the cell
Influenza (the flu)
Purpose is to replicate
Highly contagious respiratory infection
The influenza virus usually enters the body through mucus membranes in the mouth, nose, or eyes
On average in the…
cause illness by releasing chemicals that are toxic to the host or by destroying healthy body cells. Example: tuberculosis
Viruses enter the body and take over healthy a cell, which leads them to stop performing their normal tasks. Example: HIV
Fungi go into the body then break the cell wall and use its nutrients to grow. Example: zygote fungi
Protozoa are singled organisms that feed on other cells. Example: ameba
Parasites are organisms that grow and feed on the host some can even kill…
The Lymphoid System and Immunity
Dr. Jim Aston
Bacteria, viruses, parasites, allergens, foreign chemicals, and even cancer cells are
agents called pathogens that can cause disease. The body has cells capable of defending itself
in a nonspecific and very specific way if called upon to do so. The location, housing,
development, and circulation pathways for these cells are found in organs and vessels that
comprise the lymphoid system.
I. The Lymphoid /Immune System
A. Lymphatic vessels
nanoparticles in the membranes of white blood cells, scientists at the Methodist Hospital Research Institute might have found a way to prevent the human body from recognizing and destroying before they deliver their drugs. The group describes talks about their "LeukoLike Vectors," or LLVs, in a recent issue of Nature Nanotechnology.
In this article they discuss nanoparticles being able to deliver specific drug types; an example of this is chemotherapy to cancer cells. But to receive all of the benefits of…