5BIOM007W Applied Pathobiology by Tony Madgwick https://padlet.com/madgwia/appliedpathobiology Inflammatory Mediators - Class Research en-us 2016-11-08 09:45:49 UTC 2023-01-21 16:51:53 UTC hello@padlet.com Phagocytosis mediators  w1550047 https://padlet.com/madgwia/appliedpathobiology/wish/136030147 C3b and iC3b 
-C3b is important for opsonisation which is tagging pathogens, immune complexes, apoptotic cells for phagocytosis. 
-iC3b also acts as an opsonin but has a different function to C3b since they act through different complement receptor. ]]> 2016-11-08 09:50:31 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136030147 varugheseanjana https://padlet.com/madgwia/appliedpathobiology/wish/136030162 Chemotaxis : It is the movement toward or away from a chemical stimulus.Chemotaxis is a cellular function , particularly neutrophils and monocycle,where pphagocytise activity is influenced phaygocytic activity is influenced by chemical factors released by invading microorganism.(Mosb's medical dictionary, 9 th edition,2009)]]> 2016-11-08 09:50:35 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136030162 Exudation  https://padlet.com/madgwia/appliedpathobiology/wish/136030354 Initiated by inflammatory response. It is a fluid that will have different properties depending on the stimuli. It starts off with the increase in vascular permeability, this allows large molecules like immunoglobulins to move . It is important function towards microorganism neutralisation. There are five different types of exudates, serous , fibrinous, ]]> 2016-11-08 09:51:24 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136030354 Vasodilation https://padlet.com/madgwia/appliedpathobiology/wish/136030366 MEDIATORS include HISTAMINE:
synthesised in the Golgi apparatus of mast cells and basophils. 
Receptor subtypes eg H1, H2, H3, H4 etc.  
Inflammatory responses, itches, allergies. 
Causes arteriolar dilation, increased capillary permeability, contraction of nonvascular smooth muscle, and eosinophil chemotaxis and can stimulate nociceptors responsible for the pain response.

SEROTONIN: 
vasoactive mediator similar to histamine
 Found in mast cells and platelets in the GI tract and CNS.
 Serotonin also increases vascular permeability, dilates capillaries, and causes contraction of nonvascular smooth muscle.
]]> 2016-11-08 09:51:26 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136030366 Pain  https://padlet.com/madgwia/appliedpathobiology/wish/136030482 2016-11-08 09:52:05 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136030482 Fever https://padlet.com/madgwia/appliedpathobiology/wish/136030619 What is a fever?

Fever is also known as a pyrexia and febrile response. It is a abnormally high body temperature usually accompanied by shivering, headache and in severe cases delirium.

Why do we get a fever?

To raise a body's temperature enough to kill off certain bacteria and viruses sensitive to temperature changes. Fever are caused by chemicals called pyrogens. Pyrogens make their way to the hypothalamus in the brain, which is in charge of regulating body temperature.

What are the chemical mediators for fever?

iL-1: Interleukin-1 family is a group of 11 cyokines, which plays a central role in the regulation of immune and inflammatory responses to infections or sterile insults.

iL-6: Interleukins-6 is an interleukin that acts as both a pro-inflammatory cytokines and an anti-inflammatory myokine.

TNF-alpha: Tumor necrosis factor is a cell signaling protein (cytokines) involved in systemic inflammation and is one of the cytokines that make up the acute phase reaction.

Prostaglandins: are lipid audacious derived from arachidonic acid. They aid in recovery at sites of tissue, damage or infections.


]]> 2016-11-08 09:52:51 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136030619 https://padlet.com/madgwia/appliedpathobiology/wish/136030849 2016-11-08 09:53:57 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136030849 https://padlet.com/madgwia/appliedpathobiology/wish/136030961 Chemotactic factors bind to receptors on the surface of leukocytes and activate the secondary messenger system. This is stimulated by calcium ions and controlled by intracellular concentrations of cyclic nucleotides]]> 2016-11-08 09:54:29 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136030961 https://padlet.com/madgwia/appliedpathobiology/wish/136031051 e.g of chemotaxis: E-coli cells swim towards amino acids and sugars and they can swim away from noxious chemicals such as alcohols and fatty acids. E-coli uses flagella to move. ]]> 2016-11-08 09:54:54 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136031051 Pain https://padlet.com/madgwia/appliedpathobiology/wish/136031169 There are 4 chemical mediators for pain ; prostaglandins, bradykinin, histamine and serotonin. Cellular damage and inflammation increase the concentrations of these mediators.
Histamine can be released following mast cell degranulation caused by a number of inflammatory mediators. It can cause itching at low concentrations and pain at high concentrations. Allergic reaction - inflammation, vasodilation.

Bradykinin is released by blood plasma. It causes blood vessels to dilate causing bp to fall. ]]> 2016-11-08 09:55:23 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136031169 There are two types of chemoattractants in humans: exogenous and endogenous https://padlet.com/madgwia/appliedpathobiology/wish/136031185 2016-11-08 09:55:29 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136031185 Pain https://padlet.com/madgwia/appliedpathobiology/wish/136031188 2016-11-08 09:55:31 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136031188 https://padlet.com/madgwia/appliedpathobiology/wish/136031202 2016-11-08 09:55:33 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136031202 https://padlet.com/madgwia/appliedpathobiology/wish/136031308 Endogenous attractants from host: humoral (eg complement fragments) and cellular (eg leukotrienes.)
Exogenous attractants from outside: eg. bacterial oligopeptides]]> 2016-11-08 09:55:59 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136031308 https://padlet.com/madgwia/appliedpathobiology/wish/136031343 Pain is a vital function of the nervous system in providing the body with a warning of potential or actual injury.

]]> 2016-11-08 09:56:08 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136031343 Chemotaxis https://padlet.com/madgwia/appliedpathobiology/wish/136031636 movement toward or away from a chemical stimulus. Chemotaxis is a cellular function, particularlyof neutrophils and monocytes, whose phagocytic activity is influenced by chemical factors releasedby invading microorganisms.

Chemotaxis is useful in a variety of procedures in the human body, such as movement of immune cells, such as neutrophils or macrophages, towards chemoattractants released at sites of infection or injury]]> 2016-11-08 09:57:30 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136031636 Bradykinin cause blood  to dilate https://padlet.com/madgwia/appliedpathobiology/wish/136032065 2016-11-08 09:59:44 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136032065 Phagocytosis  https://padlet.com/madgwia/appliedpathobiology/wish/136032258 Mediators of phagocytosis
Alternative pathway activation...

•Slow, spontaneous background cleavage of C3 into C3a + C3b
•C3b binds to microbial cell surface
•Factor B binds to C3b to form C3bB
•Factor D cleaves C3bB to form C3bBb on the cell surface and Ba which is released
•C3bBb is stabilised by properdin
•C3bBb is C3 convertase of the alternative pathway

Control = C3b inactivated by high sialic acid content of mammalian cell membranes

- C3b is an opsonin which tags pathogens/antigens for phagocytosis ( which makes it more likely to be engulfed by macrophages)
- IgG an antibody directly stimulates phagocytosis
- When c3a is released inflammation occurs
- Phagocytosis is an immediate  response of the innate immune system ( one of the first defence mechanism in inflammation)
- Increased blood flow at affected site which increases WBC ( increase of macrophages --> increase of phagocytosis)


]]> 2016-11-08 10:00:57 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136032258 https://padlet.com/madgwia/appliedpathobiology/wish/136032353 Pain is a vital function of the nervous system in providing the body with a warning of potential or actual injury.
Inflammatory mediators (eg bradykinin, serotonin, prostaglandins, cytokines, and H+) are released from damaged tissue and can stimulate nociceptors directly. They can also act to reduce the activation threshold of nociceptors so that the stimulation required to cause activation is less. This process is called primary sensitisation.
1 The pain experienced by patients is a result of the interaction between sensory and emotional experiences.
2 Aδ fibres transmit rapid, sharp, localised pain.
3 C fibres transmit slow, diffuse, dull pain.
4 Pain transmission can be modulated at a number of levels, including the dorsal horn of the spinal cord and via descending inhibitory pathways.
5 The spinothalamic and spinoreticular tracts are important ascending pain pathways.
6 Neuropathic pain can be spontaneous and is often described as burning or ‘like an electric shock’.

]]> 2016-11-08 10:01:30 UTC https://padlet.com/madgwia/appliedpathobiology/wish/136032353 https://padlet.com/madgwia/appliedpathobiology/wish/165889754 Evading apoptosis, limitless replicative potential, self sufficiency in growth signal, sustained angiogenesis, insensitivity to anti-growth signals, tissue invasion and metastasis. ]]> 2017-04-11 14:15:21 UTC https://padlet.com/madgwia/appliedpathobiology/wish/165889754