IMMUNITY - The resistance of the body to infection, especially resistance due to antibodies. Babies have passive immunity from antibodies transferred from the mother’s blood through the placenta. Active immunity involves the formation of antibodies after exposure to an antigen (bacteria that invade the body during an infection are antigens). The two different kinds of immune response produced by antibodies involve: white blood cells called T-lymphocytes (produced by the thymus), which produce cells with antibody bound to their surface and are responsible for such reactions as graft rejection; B-lymphocytes, which produce cells that release free antibody into the blood.

 

IMMUNE SYSTEM is the complex group of defence responses found in humans and other advanced vertebrates that helps repel disease-causing organisms - pathogens. Immunity from disease is actually conferred by two cooperative defence systems, called non-specific, innate immunity and specific, acquired immunity. Non-specific protective mechanisms repel all micro-organisms equally, while the specific immune responses are tailored to particular types of invaders. Both systems work together to thwart organisms from entering and proliferating within the body. These immune mechanisms also help eliminate abnormal cells of the body that can develop into cancer.

IMMUNIZATION is the production of immunity by an injection containing antibodies against specific diseases (e.g. tetanus and diphtheria), which provides temporary passive immunity, or by vaccination, which produces the longer lasting active immunity.

IMMUNITY

Inside almost every living creature, especially mammals there is a remarkable piece of protection machinery called the immune system.

It was not always with us, but it has evolved over millions of years to defend us against millions of bacteria, microbes, viruses, toxins and parasites that might break through our initial defence, the skin, and take residence within our bodily system.

To fully comprehend the power of outside forces, consider this, many thousands die every day on our planet, simply because they, and their immune system lost the battle for life.

To fully comprehend the power of the immune system, consider that once an animal dies and is left to Mother Nature, with its bodily functions soon ceasing to work, outside and internal bacteria and insects will invade the body unabated, and within twelve months the body will be almost fully decomposed, bar for the skeleton. The bacteria and maggots will feed on rotting flesh breaking it down, turning it into various chemicals and gases.

SKIN in human anatomy, the covering, or integument, of the body's surface that both provides protection and receives sensory stimuli from the external environment. The skin consists of three layers of tissue: the epidermis, an outermost layer that contains the primary protective structure, the stratum corneum; the dermis, a fibrous layer that supports and strengthens the epidermis; and the subcutis, a subcutaneous layer of fat beneath the dermis that supplies nutrients to the other two layers and that cushions and insulates the body.

The epidermis is made up of living and nonliving layers. Its innermost layers, the basal and spinous layers, are alive, and they produce cells, called keratinocytes, that form the dead outer layer, the stratum corneum, also called the horny layer. Keratinocytes contain the tough, insoluble group of proteins known as keratins that also make up hair and nails. The horny layer forms as keratinocytes, which become thin, hard, and dehydrated and migrate upward to the surface of the epidermis. The basal layer also contains melanocytes, i.e., cells that produce the pigment melanin, which imparts color to the skin and also protects it from the effects of ultraviolet radiation. Other cells found in the epidermis include Langerhans cells, which play a role in the body's immune defenses, and Merkel cells, which are involved in sensory reception. Structures such as hair follicles, nails, and sweat and sebaceous (oil-producing) glands are appendages that develop from the epidermis and extend into the dermis.

The dermis takes up the greater part of human skin. It consists primarily of connective tissue through which an elaborate network of sensory nerves and blood vessels thread. The major component of dermal connective tissue is the extra cellular fibrous protein collagen, which provides strength to the skin and resists deformation and tearing under stress. Fibres of collagen are organized loosely in the papillary layer of the dermis, which is adjacent to the epidermis. In the reticular layer, beneath the papillary layer, the collagen fibres are denser and more branched. Another fibrous protein, elastin, which is more flexible than collagen, is found in the dermis; fibres of elastin help the skin return to its original form after it has been stretched. Elastin fibres in the papillary layer also help to anchor the epidermis to the dermis. Surrounding these fibrous bundles is an extra cellular gel like matrix called ground substance, which consists primarily of water, ions, and complex carbohydrates such as glycosaminoglycans that are often attached to proteins (proteoglycans). Ground substance helps to hold the cells of the tissue together and allows oxygen and nutrients to diffuse through the tissue to cells. Three types of cells—fibrocytes, histiocytes, and mastocytes—are scattered throughout the dermis. Fibrocytes synthesize collagen, elastin, and ground substance. Histiocytes are a type of macrophage—i.e., cells that dispose of cellular debris and invading micro-organisms by engulfing and destroying them. Mastocytes, or mast cells, are located near blood vessels; they release substances that elicit such responses as fever, edema, and pain.

The subcutaneous fat layer consists chiefly of fat cells - lipocytes, arranged into collagen-bound lobules. This fat serves as a nutritional storage depot for the entire body, and it cushions the skin and insulates the body against temperature extremes.

Vancomycin Resistant Staphylococcus Aureus

June 1997

The recently publicized finding of a strain of Staphylococcus Aureus showing resistance (or reduced susceptibility) to vancomycin has caused considerable concern, especially since the low level of the resistance means that such strains may be missed in routine laboratory anti-microbial susceptibility tests. Dr Keiichi Hiramatsu of Juntendo University, Tokyo, Japan, who described the characteristics of the vancomycin-resistant strain, has provided a summary and a provisional method for detection available on EMC's web site for Anti-microbial Resistance. An account of his findings will be published in Journal of Anti-microbial Chemotherapy in July 1997. 

Methicillin-resistant Staphylococcus Aureus (MRSA)?

Methicillin-resistant staphylococcus Aureus is a bacterial infection resistant to antibiotic Methicillin. Staphylococcus Aureus, sometimes referred to simply as "staf" or "staph A" is a common bacterium found on the skin of healthy people. If staph gets into the body it can cause a minor infection such as boils or pimples or serious infections such as pneumonia or blood infections.

MRSA

Methicillin-Resistant Staphylococcus Aureus produces symptoms no different from any other type of Staphylococcus Aureus bacteria. The skin will appear red and inflamed around wound sites. Symptoms in serious cases may include fever, lethargy, and headache. MRSA can cause urinary tract infections, pneumonia, toxic shock syndrome, and even death.

The organism Staphylococcus Aureus is found on many individuals skin and seems to cause no major problems. However if it gets inside the body, for instance under the skin or into the lungs, it can cause important infections such as boils or pneumonia. Individuals who carry this organism are usually totally healthy, have no problems whatever and are considered simply to be carriers of the organism.

The term MRSA or Methicillin resistant Staphylococcus Aureus is used to describe those examples of this organism that are resistant to commonly used antibiotics. Methicillin was an antibiotic used many years ago to treat patients with Staphylococcus Aureus infections. It is now no longer used except as a means of identifying this particular type of antibiotic resistance.

Individuals can become carriers of MRSA in the same way that they can become a carrier of ordinary Staphylococcus Aureus which is by physical contact with the organism. If the organism is on the skin then it can be passed around by physical contact. If the organism is in the nose or is associated with the lungs rather than the skin then it may be passed around by droplet spread from the mouth and nose. We can find out if and where Staphylococcus Aureus is located on a patient by taking various samples, sending them to the laboratory and growing the organism. Tests done on any Staphylococcus Aureus grown from such specimens can then decide how sensitive the organisms is to antibiotics and if it is a Methicillin resistant (MRSA) organism. These test usually take 2-3 days.

Can MRSA be treated?

Yes. While MRSA is resistant to many antibiotics and can be difficult to treat there are a few antibiotics that can cure MRSA infections. Patients that are only colonized with MRSA usually do not require treatment.

Bacteria  - Microscopic single-celled organisms found wherever life is possible. Generally 0.0001–0.005 mm long, they may be spherical - coccus, rodlike  - bacillus, or spiral-shaped - spirillum and often occur in chains or clusters of cells. True bacteria have a rigid cell wall, which may be surrounded by a slimy capsule, and they often have long whip-like flagella for locomotion and short hair-like pili used in a form of sexual reproduction. A few bacteria can use simple chemical substances, including carbon dioxide from the atmosphere, to manufacture their own nutrients, but most require a source of carbon derived from living organisms (i.e. organic carbon) plus other nutrients for growth. Some bacteria can reproduce every 15 minutes, leading to rapid population growth.

 

The most important role of bacteria is in decomposing dead plant and animal tissues and releasing their constituents to the soil (see carbon cycle). Nitrogen-fixing bacteria in the soil or sea convert atmospheric nitrogen gas to nitrites and nitrates, which can then be used by plants (see nitrogen cycle). Cheese making and fermentation reactions depend on bacteria. Bacteria also play an important part in animal digestion, especially in ruminants. However, certain (pathogenic) species may cause disease while others, such as Salmonella, can cause food poisoning.

How Does Your Body Fight Infection?

Immunity   -  The resistance of the body to infection, especially resistance due to antibodies. Babies have passive immunity from antibodies transferred from the mother’s blood through the placenta. Active immunity involves the formation of antibodies after exposure to an antigen - bacteria that invade the body during an infection are antigens. The two different kinds of immune response produced by antibodies involve: white blood cells called T-lymphocytes - produced by the thymus, which produce cells with antibody properties bound to their surface and are responsible for such reactions as graft rejection; B-lymphocytes, which produce cells that release free antibody into the blood.

Leucocyte - lymphocytes - or white blood cell. A colorless cell found in large numbers in the blood. There are several kinds, all involved in the body’s defence mechanisms. Granulocytes and monocytes destroy and feed on bacteria and other micro-organisms that cause infection -  see also phagocyte. The lymphocytes are involved with the production of antibodies.

Phagocyte   -  A cell that engulfs and then digests particles from its surroundings: this process is called phagocytosis. In vertebrate animals, phagocytes are a type of white blood cell that protect the body by engulfing bacteria and other foreign particles.

Immunization is the production of immunity by an injection containing antibodies against specific diseases e.g. tetanus and diphtheria, which provides temporary passive immunity, or by vaccination, which produces the longer lasting active immunity.

Antibody   -  A protein produced by certain white blood cells  - lymphocytes that reacts with a particular foreign particle e.g. a bacterium,  that has entered the body. The antibody helps to destroy the foreign particle, known as the antigen. If the same bacteria invade the body in future, many more of the same antibodies are produced, enabling the body to destroy the bacteria very rapidly and so resist infection. This provides the basis of  immunity. Antibodies are also responsible for the rejection of foreign tissue or organ transplants. See also monoclonal antibody.

Monoclonal antibody  -  A type of pure antibody that can be produced artificially in large quantities and used, for example, to distinguish the major blood groups. Mouse lymphocytes producing the required antibody are fused with mouse cancer cells; the resulting hybrid cells multiply rapidly and all produce the same type of antibody as their parent lymphocytes.

Whilst all this bodily protection sounds wonderful, the problem with MRSA, is that there is no defense to it, no answer to its attack.

Blood cells

There are a number of different cell types in circulation in the blood stream. Here's a quick review:

Red cells carry oxygen to the cells of the body. They are essentially bags of hemoglobin, the oxygen carrying molecule. Hemoglobin binds oxygen to iron atoms, which give the hemoglobin and thus the cells their distinctive red color.

Polymorphonuclear cells, or "polys" for short, fight bacterial infections by engulfing bacteria and digesting them. They form PUS and are the chief ingredient of an abscess.

Lymphocytes are the virus killers. There are two types of these:

T-cells which remember what germs we've been exposed to and how to kill them. T-cells are the key component of the immune system that is missing in AIDS.

B-cells that secrete the actual antibodies that attach to viruses and bacteria and identify them as things to be destroyed - rather like tagging the target with a laser so that the smart bomb will home in and blast the target.

Monocytes are cells that are related to lymphocytes but have a killing and cleaning function. They cruise through the tissues of the body cleaning up debris and killing any bacteria they find. They are often increased in viral infections - a reassuring finding that your doctor may note on your child's blood count.

Eosinophils are cells which are strongly related to allergy and the recognition of foreign things in the body like parasites.

Basophils are cells that are also part of the allergy and parasite recognition system.

Platelets are the cells that plug leaks in the vascular system, the clotting cells.

Prion - An an infectious protein particle called a Prion or Prion Protein. These prions appear to have the ability to recruit other normal proteins and induce them to alter their structure to become more prions, that act as vehicles of infection. This is quite different from other infectious diseases, commonly caused by bacteria or viruses. Prions are not a genetic.

  Asthma - Athletes Foot - MRSA - Anthrax -  Malaria - Head Lice -Meningitis - Piles - Worms - Smelly Feet - Allergies  

  All suburls are, © copyright of Foogle Business 2006 

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