WOUND DICTIONARY

Saldy Yusuf, S.Kep.Ns.ETN

ABPI
Ankle Brachial Pressure Index. A hand-held Doppler ultrasound test used to determine the presence and degree of peripheral arterial disease in patients with leg ulcers.

Adhesion (Cell adhesion)
Cell to cell attachment and cell to matrix attachment are often referred to as cell adhesion. Cells bind to matrix molecules (or cell surface molecules) via adhesion sites on the cell surface, e.g. integrins. The binding strength is low for these adhesion sites and the cell adhesion strength relies on simultaneous binding of multiple integrins to multiple ligands in the adjacent matrix, sometimes referred to as the “Velcro principle”.

Adhesion protein
See Extracellular matrix.

Alginate
A dressing made from seaweed which can be composed of the steams – G alginate (galuronic) and from the leaves M alginate (mannuronic acid), with the proportions of these determining the gel forming properties of the final fibre. G is more gel forming than M. Best used in moderate to highly exuding wounds. If the wound bed is too dry the alginate will not gel and will adhere to the wound bed. Some alginates have haemostatic qualities.

Amelogenins
Extracellular proteins and the major organic component in the enamel matrix of developing teeth. They are therefore also called enamel matrix proteins. Amelogenin self-assembles, under physiological conditions, to large protein aggregates to which cells adhere. See also Enamel matrix protein.

Anaerobic bacteria
Bacteria that multiply in the absence of free oxygen.

Anaesthesia
Medical treatment to reduce feeling of pain, heat, cold, touch etc

Angiogenesis
The proliferation of new blood vessels. Angiogenesis within a wound occurs during the proliferative phase of healing. The extracellular matrix provides the scaffolding into which new capillaries will grow.

Antibacterial
Agent that acts against bacteria.


Antibiotic
Agent tending to prevent or destroy life, used to treat infection.

Antibiotic resistance
Property of micro-organism to resist inactivation by antibiotics.

Antimicrobial
Agent that acts against micro-organisms (includes bacteria, fungi, virus, and protozoa). Antimicrobial is a "broader" term than antibacterial.

Antiseptic
Chemical agents that can be used on skin or living tissue to inhibit or eliminate micro-organisms. Antiseptics can be dilute disinfectants; they are not selective and therefore can be toxic to the host tissue, particularly at higher concentrations. Antiseptics have the advantage of rarely selecting for resistant microbial strains, and being topical, do not rely on the bloodstream for access to the wound; this is particularly important for wounds with poor blood circulation.

Asepsis
Keeping an object free from contamination by micro-organisms. Antisepsis is the use of a substance, which prevents or inhibits the growth of micro-organisms without necessary destroying them.

Apoptosis
Programmed cell death. Apoptosis is an active self-destructive process, which is part of the normal process of growth control. Apoptosis is fundamental to the maintenance of homeostasis, tissue repair and regeneration.

Autolysis
The term used for the natural, spontaneous process of devitalized tissue being separated from viable tissue. Together with proteolytic enzymes, macrophage activity is thought to be responsible for autolysis. Disintegration or liquification of tissue or cells by the body's own mechanisms (leukocytes or enzymes); as in autolytic Debridement.


Bacteria
1-10 µ small primitive single cells. They can aggregate and look like twins or in chains or in grape like clusters.

Bactericidal
Agent that kills bacterial cells.

Bacteriostatic
Agent that prevents bacteria from multiplying.

Basement membrane
Also called basal lamina. Thin mat of extracellular matrix that separates epithelial tissue from connective tissue, e.g. the epidermis from dermis.

Biofilm
Microbial community associated with a surface. In natural environments, the biofilm is often made up of a multispecies microbial community enclosed in slime, made up of polysaccharides. This slime renders the microbes more resistant to environmental factors such as antibiotics.

Blister
Elevation of the epidermis containing watery liquid.



Capsule
Dense layer of protein or polysaccharide that surrounds a bacterial cell.

Carbon-Silver dressing
Carbon dressing impregnated with Silver. Activated charcoal attracts and traps bacteria and odour.

Cell
All living organisms are composed of one or more cells. A cell is an autonomous self-replicating unit that may constitute an organism (in the case of unicellular organisms) or be a subunit of multi-cellular organisms in which individual cells may be more or less specialised (differentiated) for particular functions.

Cell adhesion
See Adhesion.

Cell membrane / Plasma membrane
Membrane that surrounds a living cell. A cell membrane is a double layer of lipid molecules, so called phospholipids, and associated proteins.

CFU; colony forming units
CFUs represent single microbial cells or clumps of cells that form distinct colonies when grown in vitro, a way of viable counting in microbiology.

Charcot foot
is a term used to characterize a progressive arthropathy common to diabetes mellitus. A Charcot deformity is a destruction or fragmentation of the bones of the foot.

Chemokines
Small cellular signals that stimulate chemotaxis (which means cell motion toward, or away from, a chemical gradient) e.g. migration of leukocytes into the tissue from blood vessels. Chemokines function by binding to receptors on the surface of or inside target cells.

Chemotaxis
Motile response of a cell or an organism that carries it toward or away from a diffusible chemical in their environment. The movement is affected by the concentration gradient of the substance.

Collagen
Fibrous protein that is a major component of the extracellular matrix and connective tissues. Exists in many forms: type I, the most common is found in skin, tendon, and bone. Type IV is present in basal membranes. Collagen may be detected in a wound within 10 hours following injury. It is synthesised and modified during the proliferative and maturation phases of wound healing.

Colonisation
Multiplication of micro-organisms without a corresponding host reaction.

Contamination
Transient presence of bacteria which do not cause local or systemic symptoms of disease, no total increase of microbial population.

Critical colonization
Multiplying microbes with some local signs but no systemic signs leading to impaired healing.

Cytokines
Small, extracellular cell signals (polypeptides / proteins) that act as local mediators in cell communication. They affect the behaviour of cells, such as macrophages’ expression of growth factors, neutrophils’ migration to the wound site and fibroblast proliferation. Cytokines are released, mainly by neutrophils and macrophages, during episodes of inflammation, and they are crucial for the normal healing process. The cytokine activates the cell by binding to a specific cell surface receptor, associated with an intracellular enzyme that initiates a series of reactions in the cell.

Cytoplasm
Contents of a cell that are contained within its cell membrane but outside the nucleus, that is, a collective term for cytosol and organelles. Cytosol, the colloidal suspension within a cell, is mainly composed of water with ions and organic molecules and its viscosity constantly changes due to cellular metabolism.

Cytosol
See Cytoplasm.

Cytotoxic
Agent that is toxic to living cells.




Deoxyribonucleic acid (DNA)
The genetic material of all cells and many viruses. Deoxyribonucleic acid is the double-helix molecule holding the genetic information of organisms. DNA along with protein composes the chromatin (chromosomes).

Debridement
Removal of devitalised tissue (surgical, mechanical, enzymatic, autolytic etc).

Debris
Remains of broken down or damaged cells or tissue.

Differentiation
Process in development of cells in a multicellular organism by which cells become specialized for particular functions.

Disinfections
Agents that destroy the micro-organisms from inert surfaces, used particularly on instruments, work surfaces, etc. Not intended for use on the tissue. Not effective on bacterial spores and other relatively resistant organisms e.g. mycobacteria, nonlipid virus and fungi. Reduction of bioburden with > 5 log steps is expected.




Elastase
Enzyme that digests elastin, which leads to tissue break down. P. aeruginosa produce elastases.

Enamel matrix protein
Proteins found in the enamel-forming region on developing teeth, mainly amelogenin. These proteins are adhesive extracellular matrix proteins involved in tissue development and are not found in the organism after the teeth have been fully developed.

Endotoxin
A part of the bacterial body, freed when the bacteria disintegrates, e.g. LPS

Endoplasmic reticulum
An organelle of eukaryotic cells consisting of a membrane network that is fused to the nuclear membrane and which passes through the cytoplasm. It is the site for protein and lipid synthesis, "rough" and "smooth" ER, respectively, where rough refers to ribosomes attached to the membrane.

Enzyme
Protein that catalyses a specific chemical reaction, that is, speeding up the reaction by reducing the activation energy for a particular chemical change. Each enzyme has a unique shape and binds a particular set of other molecules, called substrates. Enzymes molecules themselves are not changed after participating in a reaction and therefore can function over and over again.

Epithelialisation
The final stage of wound healing where epidermal cells migrate across the surface of the wound from the wound margins and the remaining hair follicles.

Erythema
A redness of the skin owing to hyperaemia.

Erythrocytes
Red blood cells.

Eschar
A thick coagulated crust or slough which develops in both acute and chronic wounds consisting of dried serum and devitalised dermal cells.

Eucaryotic cell
All cells are classified as either eucaryotes or procaryotes. All cells in multicellular organisms, and in unicellular organisms other than bacteria, are eucaryotic cells that in contrast to prokaryotic cells have a distinct nucleus surrounding its genetic material and cytoplasm containing numerous membrane-bound organelles.

Exotoxin
A toxin produced by micro organisms and released into the surrounding.

Extracellular matrix (ECM)
Complex network of macromolecules filling up the extracellular space in animal tissues. The ECM is composed of a variety of proteins and polysaccharides that are secreted locally and assembled into an organized meshwork in close association with the cells that produced them (mainly the fibroblasts cell family). Some of the ECM proteins are referred to as structural- and adhesion proteins, e.g. collagen and fibronectin. They serve as structural elements in tissues and influences their development and physiology, respectively. In connective tissue the ECM is more plentiful than the cells it surrounds and it determines the tissue’s physical properties.




Fibroblast
A connective tissue cell that secretes proteins and especially molecular collagen from which connective tissue is developed.



Film dressings
Used as primary of secondary dressing. Semi-permeable films are made of clear polyurethane coated with an adhesive. They are conformable and resistant to shear and tear. They prevent bacterial colonisation but do not absorb exudate.

Fibrin
Fibrin is produced from fibrinogen by proteolytic removal of the highly charged fibrinopeptides by thrombin, in the presence of calcium ions. The fibrin gel, formed during blood clotting (fibrin clot), acts as a haemostatic plug, and matrix for early wound healing.

Fibrin clot / fibrin matrix
See Fibrin.

Fibrinogen
A soluble blood plasma protein that is the precursor protein of fibrin.

Fibroblast
Resident cell of connective tissue that secretes ECM components (fibrillar procollagen,elastin, fibronectin and ECM polysaccharides) and necessary proteinases and cell signals. Fibroblasts numbers increase in injured tissue where they respond to chemotactic stimuli. Fibroblasts also stimulate cell migration, angiogenesis, soft tissue growth and repair.

Fibronectin
An adhesion protein produced mainly by fibroblasts and macrophages. It is a glycoprotein that occurs in insoluble fibrillar form in the extracellular matrix of animal tissues, and soluble in blood plasma. Fibronectins have multiple functions that confer the ability of cells to interact with many extracellular substances such as collagen, fibrin and heparin, and also with specific cell surface receptors on responsive cells.

Foam dressing
A dressing produced from polyurethane a soft, open cell sheets and may be single layer or multiple layers. They are non-adherent, can absorb large amounts of exudate and can also be used as secondary dressings. They are also available impregnated with charcoal and with a waterproof backing.




Gangrene
A complication of necrosis (cell death) characterized by the decay of body tissues, which become black (and/or green) and malodorous. It is caused by infection or ischemia.

Glycosaminoglycan
Long linear highly charged polysaccharide composed of a repeating pair of sugars. Mainly found linked to a protein core in extracellular matrix proteoglycans, such as hyaluronic acid.

Glycoprotein
A protein, which has attached branching carbohydrates. Many plasma membrane proteins are glycoproteins and these may function in cell-cell recognition, such as in human blood groups and immune system response.

Golgi complex
Membrane-bounded organelle in eucaryotic cells where the proteins and lipids made in the endoplasmic reticulum are modified and sorted. Also referred to as Golgi apparatus.

Gram-negative
Bacteria that stain red with Gram's stain, e.g. Escherichia coli (survive under wet conditions).

Gram-positive
Bacteria that stain blue with Gram's stain, e.g. Staphylococcus aureus (survive under dry conditions).

Granulation
The bright red tissue formed from new capillary loops during the proliferative phase of healing.

Ground substance
A term that is often used for the gel-like water containing polysaccharides and proteoglycans in the extracellular matrix.

Growth factors
Growth factors are a subset of cytokines, cell signals, which have a number off functions including regulation and coordination of cell and tissue growth and development, and processes such as wound healing. There are numerous different growth factors with different functions, which have the potential to enhance wound healing through several mechanisms (see wound healing module). Examples of growth factors involved in wound healing are EGF (epidermal growth factor), PDGF (platelet-derived GF), FGF (fibroblast GF). See also Cytokines.




Haemostasis
The process that induces blood clotting and controls bleeding.
Homeostasis
The process by which the body maintains health in order to survive. The maintenance of normality is a delicate balance and includes regulation of blood pressure, temperature, pH etc.

Hyaluronic acid (HA)
Also known as hyaluronan. It is the main polysaccharide component (glycosaminoglycan) of the extracellular matrix and is found in most areas of the body. Tissues show an increase in HA in the early stages of repair and regeneration. HA stimulates cytokine production by macrophages to promote angiogenesis.

Hydrocolloid
A waterproof, occlusive dressing that consists of a mixture of pectin, gelatine, sodium carboxymethylcellulose and elastomers. Hydrocolloids create an environment that encourages autolysis to debride wounds that are sloughy or necrotic. As the hydrocolloid mixes with exudate, it produces a yellow gel with a characteristic odour.

Hydrofibre
A highly absorbent wound dressing made up of 100% Hydrocolloid (Sodium Carboxymethylcellulose). The hydrocolloid is spun into fibres and needled to make a soft, non-woven fleece-like dressing that comes as a sheet or ribbon. An alternative to alginate dressing. The dressing retains a high quantity of water without releasing it, thereby forming a thick conformable gel.

Hydrogel
A dressing that comes as a sheet or gel. Sheets are used for shallow or low exuding wounds. The gels are suitable for cavities and are effective for desloughing and debriding wounds. Gels have a high water content, which aids the rehydration of hard eschar and promotes autolysis in necrotic wounds. Secondary dressing is required to keep the gel moist and in situ. To prevent possible maceration a protective barrier film may be applied on peri-wound areas.

Hypoxia
Deficiency in the amount of oxygen delivered to the body tissues. All wounds are hypoxic at first, a situation that may persist in chronic wounds. There is considerable evidence that early hypoxia has a stimulatory effect on the healing process, while the persistence of low oxygen tension may actually impair wound repair.




Incubation
In bacteriology; the cultivation time.

Infection
Presence of micro organisms capable of tissue destruction and invasion or formation of toxins, accompanied by local or systemic signs or symptoms.

Inflammation
Defensive reaction to tissue injury (not necessarily microbial cause); involves increased blood flow and capillary permeability with migration of white blood cells which facilitate physiologic clean up of wound. Signs and symptoms: heat (calor), redness (rubor), swelling (tumor), pain (dolor).

Interleukin
Cell signals, cytokines, produced by leucocytes (not exclusively), which function during inflammatory responses. Many cytokines are initially given descriptive names but, as their basic structure is identified, they are renamed as “interleukins” (messengers between leukocytes). E.g. interleukin-1, or IL-1, that e.g. helps to activate B- and T-lymphocytes during inflammation.

Integrins
Membrane proteins involved in the adhesion (attachment) of cells to the
extracellular matrix.

Invasive
An organism or a device (e.g. needle) that penetrate tissue.

In vitro
Literally means ‘in glass’. It is a general term for cells, or experiments performed on cells, in culture as opposed to cells in a multicellular organism.

In vivo
Literally means ‘in life’. It is a general term used to describe cells in their natural multicellular environment, or experiments done on intact organisms, rather than on isolated cells in culture.

Infection
The deposition and multiplication of organisms in tissue with an associated host reaction.

Inflammation
Bacteria are killed, foreign matter and toxins are removed and damaged tissue is walled off. Symptoms are: erythema, raised temperature, swelling, exudate and pain.




Keratinocyte
The predominant cell type of the epidermis, which synthesises keratin. These cells divide at the basement membrane and migrate slowly towards the surface of the skin.




Larval therapy
The use of Lucilla serecata (10 pcs/ cm2 wound surface) for debridement. The specially bred, sterile maggots liquefy dead tissue using enzymes. The treatment appears to have very few adverse side-effects.

Leukocyte
White blood cell.

Ligand
Any molecule that binds to a specific binding site on a protein or other molecule. Binding of the ligand may transfer information or activate the binding site or receptor in different ways depending on type of ligand - receptor pair.

Lipids
Are composed of fatty acids and do not disperse in water, so they are hydrophobic.

Lymphocyte
White blood cell that makes an immune response when activated by a foreign molecule (an antigen). They are derived from stem cells within the lymph nodes. B-lymphocytes (when activated) are responsible for the production of circulating antibodies.
T-lymphocytes are subdivided into subsets (helper, suppressor, cytotoxic T-cells), and are responsible both for cell-mediated immunity and for stimulating B-lymphocytes.

Lysosome
Membrane-bounded organelle, in eucaryotic cells, containing digestive enzymes, which are typically most active at the acid pH found in the lumen of lysosomes. Lysosomes transport undigested material to the cell membrane for removal. Uncontrolled release of lysosomal enzymes in a cell leads to autolysis and cell death.




Maceration
A softening or sogginess of the tissue owing to retention of excessive moisture.

Macrophage
White blood cell that is specialized for the uptake of particulate material by phagocytosis. It is derived from blood monocytes that differentiate to macrophages after migrating from the circulating blood into the tissue. Macrophages from different sites have distinctly different properties. Main types are peritoneal, alveolar and tissue macrophages. Beside phagocytosis, tissue macrophages play an important part in wound healing as they synthesise and secrete cytokines to control the wound healing process. Macrophages also play an important role in killing of some bacteria, protozoa, and tumour cells and release substances that stimulate other cells of the immune system.

Matrix metalloproteinases (MMPs)
Proteolytic enzymes necessary for growth, development and tissue repair and regeneration, which are produced by e.g. fibroblasts and macrophages. Collagenases and elastases, are examples of MMPs that break down specific proteins and help to remodel the extracellular matrix.

MBC
Minimum Bactericidal Concentration.
Membrane /Biological membrane
A double layer of lipid molecules, so called phospholipids, that encloses all cells and, in eukaryotic cells, many organelles.

Metabolism
The sum total of the chemical processes that takes place in living cells.
Metabolic activity
See metabolism.

MIC
Minimum Inhibitory Concentration.

Micrometer, μm, micron
Micro- is a prefix denoting 10-6; A micrometer is 10-6 meter = 0.001 mm.

Microbe
See micro-organism.

Micro-organism
Organisms of microscopic size, generally less than 0.01 mm. Includes bacteria, fungi (yeasts and moulds), viruses, and protozoa.

Mitochondrion
Membrane-bounded organelle, about the size of a bacterium, which carries out oxidative phosphorylation and produces most of the ATP in eucaryotic cells. Mitochondria are thus the cellular ‘powerhouse’ producing energy for overall cell metabolism and other active processes e.g. movement, wound healing processes

Mitogen
Extracellular substances, such as a growth factor, that stimulates cell proliferation (i.e. cell growth and division).

Monocyte
White blood cell, a so-called mononuclear phagocyte, in circulating blood, that will later pass into tissues and differentiate into a macrophage.

MRSA
Methicillin Resistant Staphylococcus aureus. MSRA are resistant to a range of antibiotics.

Myofibroblasts
Differentiated fibroblasts that contain actin microfilaments, myosin and other muscle proteins that produce contractile forces. They behave in a similar way as smooth muscle cells. These cells are motile and pull wound tissue together in the contraction phase of healing to reduce the wound volume.




Necrosis
The local death of tissue. This tissue is often black/brown in colour and leathery in texture.

Neutrophil
Commonest type of white blood cells, (leucocytes) that constitute 2/3 of all white blood cells and are specially attracted to skin, where they play an important role to destroy foreign particles e.g. microbes. These phagocytic cell are short lived and are responsible for the primary cellular response to an acute inflammatory episode.

Nosocomial infection
Hospital acquired infection (HAI), MRSA is a common cause of HAI.

NPWT
Negative pressure wound therapy is a system that creates a hypoxic environment within the wound bed in which aerobic bacteria cannot survive. The environment forces the microcirculation to regenerate rapidly and produce large amounts of capillaries. The negative pressure also removes slough, loose necrotic material and exudate from the wound bed.

Nucleus
The major organelle of eukaryotic cells, containing the genetic material, DNA, organized into chromosomes.




Osteomyelitis
Is an infection of bone or bone marrow, usually caused by pyogenic bacteria or mycobacteria.

Organelle
Specialized part of a cell, often surrounded by a membrane (e.g. mitochondrion) analogous to an organ in the body.

Oxidation
The process of removing electrons from a substance by adding more oxygen, or removing hydrogen, which changes its chemical structure and reactivity. Opposite of reduction.





Pathogen
Disease producing micro-organism.

Pathogenicity
The ability to produce pathological changes and disease.

Peptide
Short linear molecule composed of amino acids, bound together by so called peptide bonds. See polypeptide.

Phagocyte
General term for a phagocytic cell, that is, a cell such as a macrophage or neutrophil that is specialized to take up particles or microorganisms by phagocytosis.

Phagocytosis
Process by which particulate material, such as necrotic tissue, bacteria and cellular debris, is endocytosed (“eaten”) by a cell. Prominent in macrophages and neutrophils.

Phenotype
The observable character of a cell or an organism. That is, an organism has one genotype but can express different phenotypes, depending on changes of environmental factors.

Plasma membrane
See Cell membrane.

Plasminogen
Inactive precursor of plasmin, which is a hydrolytic enzyme that degrades fibrin.

Platelet
Small cell-like structures, that lack nucleus and genetic material, found in large numbers in the bloodstream. They are important for blood coagulation and for haemostasis. Platelets release granules, containing lysosomal enzymes, following injury to initiate the clotting cascade. Platelets also release platelet-derived growth factor, which contributes to tissue repair by stimulating fibroblast proliferation.

Polyneuropathy
is a neurological disorder that occurs when many peripheral nerves throughout the body malfunction simultaneously.

Polypeptide
Line ar polymer composed of multiple amino acids. Proteins are large polypeptides, and the two terms can be used interchangeably.

Polysaccharide
Line ar or branched polymer of monosaccharides. These include glycogen, hyaluronic acid and cellulose.

Primary Intention
The process of healing a wound with minimal tissue loss where the wound edges can be brought together e.g. surgical wounds. Within 48 hours the epidermis will have sealed the wound so that healing can continue below the surface. These wounds heal mainly due epithelialisation in the maturation phase of healing and is much quicker than wounds healing by secondary intention.

Procaryotic cell
Organisms, namely bacteria, characterised by a simple DNA chromosome, usually of circular structure, without a nuclear membrane. They are smaller and not advanced as eucaryotic cells and generally possess no other organelles than plasma membrane and ribosomes.

Propylene glycol alginate (PGA)
A propylene glycol ester of algenic acid, used as a vehicle or carrier for the amelogenin protein in Xelma.
Protease (proteinase, proteolytic enzyme)
Enzyme such as trypsin that degrades proteins by hydrolysing some of their peptide bonds.

Protein
The major macromolecular constituent of cells. A linear polymer of amino acids linked together by peptide bonds in a specific sequence.

Proteoglycan
A high molecular weight complex of glucosaminoglycans (polysaccharides) attached to a core protein, characteristic of structural tissues such as bone and cartilage, but also present on cell surfaces.

Proteases
Also called proteinases. Enzymes that hydrolyse proteins, e.g. elastase.

Proteolysis
Degradation of a protein, usually by hydrolysis at one or more of its peptide bonds.

Punch biopsy
A punch skin biopsy is a procedure to remove a small piece of skin tissue for examination under a microscope. It is usually carried out to determine or confirm a diagnosis. A skin punch biopsy needle is gently inserted into the skin, rotated and a small circle of skin carefully removed. The biopsy site usually bleeds slightly straight after the procedure, but this will stop when pressure is applied to the site.

Pus
Thick fluid usually indicative of infection; contains leukocytes, bacteria, and cellular debris.

Pyogenic
Bacterial infections that make pus or form abscesses.




Receptor
Protein that binds a specific extracellular signalling molecule (ligand) and initiates a response in the cell. Cell surface receptors, such as acetylcholine receptor and the insulin receptor, are located in the plasma membrane, with their ligand-binding site exposed to the external medium. Intracellular receptors, such as steroid hormone receptors, bind ligands that diffuse into the cell across the cell membrane.

Recombinant DNA
Any DNA molecule formed by joining DNA segments from different sources. Recombinant DNAs are widely used in the cloning of genes, in the genetic modification of organisms, and in molecular biology in general. This process is used when creating substances such as growth factors artificially, by inserting appropriate genetic material in e.g. bacteria or yeast cells.

Resistance
Resistance/Insensitivity is the ability of a microbe to resist antimicrobial agents.

Ribosome
Particle composed of ribosomal RNAs and ribosomal proteins that associate with messenger RNA and catalyses the synthesis of protein. Each cell contains thousands of ribosomes comprising 25% of the cell's mass. Some ribosomes are stationary and are embedded in rough endoplasmic reticulum, others are mobile and injects the newly synthesized proteins directly into the cytoplasm.




Secondary Intention
The process of healing in wounds with significant tissue loss e.g. leg ulcers, pressure ulcers. These wounds are left open due to the amount of tissue loss or because the wound edges cannot be brought into close apposition. These wounds heal mainly due to granulation and contraction in the proliferative phase of healing and take longer than wounds healing by primary intention.

Slough
The term for the viscous yellow layer which often covers the wound and is strongly adherent to it. Its presence can be related to the end of the inflammatory stage of healing when dead cells have accumulated in the exudate.

Species
A genus or family of bacteria, e.g. Pseudomonas aeruginosa.

Sterilization
The use of physical procedures or chemical agents on non-living objects to destroy all microbial forms, including bacterial spores. The probability of surviving micro-organism should be < 10-6
Strain
A defined organism of a defined species of microorganisms. For instance, there is a MRSA outbreak and several different strains were isolated from each patient, however they all belong to the same species.

Strike-through
The point at which a liquid pathway is formed between the inner and outer surfaces of a dressing by the penetration of blood, exudate or tissue fluid.
Structural protein
See Extracellular matrix.




Transduction / Signal transduction
The conversion of a signal from one form to another. For example, various types of sensory cells convert or transduce light, pressure, chemicals, etc. into nerve impulses and the binding of many hormones to receptors at the cell surface is transduced into an increase in AMP within the cell.


Virulence
The ability to cause disease.

Virulence factors
Virulence is the degree of pathogenicity and invasiveness of an invading micro-organism. The various factors include toxins, enzymes such as coagulase and collagenase, bacterial antigens, fimbriae, capsule, and flagella.

VRE
Vancomycin Resistant Enterococci (Enterococcus faecium or Enterococcus faecalis).



Wound bed
Uppermost viable layer of wound; may be covered with slough or eschar.

source:http://www.less-pain.com/dictionary_a.html