Immune mechanisms

AType II allergic reaction occurs when antibodies specific for foreign substances recognize the body s own cells after they have firmly bound these foreign substances and initiate the cell s destruction by immune mechanisms. 

Pichler WJ. Immune mechanism of drug hypersensitivity. Immunol Allergy Clin North Am 2004 24 373-397. 

Love, R.J., Ogilvie, B.M. and McLaren, D.J. (1976) The immune mechanism which expels the intestinal stage of TrichineUa spiralis from rats. Immunology 30, 7-15. 

Infections can damage nerves directly, or via exotoxins 621 Antibody- and cell-mediated mechanisms of neuropathy 621 Immune mechanisms contribute to paraneoplastic neuropathies 623 Toxins and hormone deficiency states are frequent causes of neuropathy 623 Many genetically determined neuropathies are now recognized 624 Neurofibromatosis is a frequent cause of peripheral nerve tumors 625... 

The demyelination occurring in these conditions is likely to be mediated at least in part by immune mechanisms since T cells sensitized to MBP are detected in many of these patients. 

Kieseier, B. C., Dalakas, M. C. and Hartung, H. P. Immune mechanisms in chronic inflammatory demyelinating neuropathy. Neurology 59, S7-S12, 2002. 

Nistico, G. et al., Evidence for an involvement of dopamine D1 receptors in the limbic system in the control of immune mechanisms, Neuroimmunomodulation, 1, 174, 1994. 

Respiratory hypersensitivity is an adverse reaction in the respiratory tract driven by immune mechanisms such as IgE antibody mediated allergic responses. Other less well understood mechanisms that have an immune component are also involved in respiratory hypersensitivity. OA is one outcome of respiratory hypersensitivity. Respiratory hypersensitivity and OA to proteins are primarily mediated by IgE antibody with subsequent inflammatory cell infiltrates. This same mechanism is responsible for OA to specific LMW chemicals such as the acid anhydrides and platinum salts. However, the role for IgE mediated responses in OA to other LMW chemicals such as the isocyanates and plicatic acid is poorly defined and other mechanisms may be responsible. 

Ahlstedt, S. and Kristofferson, A., Immune mechanisms for induction of penicillin allergy,... 

Thus, together these studies suggest that the oxidative burst machinery has evolved before the crown diversification of eukaryotes (Baldauf 2003) to provide marine algal lineages with natural and induced innate immunity mechanisms. These play a role similar to the HR in terrestrial plants infected by incompatible pathogens and they share important common traits with the innate immunity response of mammalian phagocytes. 

IgG comprises some 80% of the total immunoglobulin in plasma and because it is relatively small it is capable of crossing membranes and diffusing into the extravascular body spaces. It can cross the placental membrane and provides the major immune defence during the first few weeks of life until the infant s own immune mechanism becomes effective. 

Many parasitic diseases are associated not only with an impairment of humoral antibody synthesis, but also with an impaired cellular response, and one wonders whether these may have originated from an earlier nutritional effect on immune mechanisms (S2). 

West Africans resident in Britain had average y-globulin levels for those in Britain less than two years of 2.2 g/100 ml as compared with 2.0 g/100 ml for those resident two to four years and 1.6 g/100 ml for those resident five to eight years (S3). Specific host factors in which the immune mechanism are implicated was believed to account for the higher levels of y-globulin in American Negroes and Puerto Ricans than in white races (S9). 

The higher than normal serum IgA in many children with protein calorie malnutrition may be related to increased synthesis of IgA by the intestinal lamina propria in resjionse to increased antigenic stimuli from bacteria and virus. This is probably supported by the observation that children with kwashiorkor were found to maintain their polio antibodies during malnutrition, and their immune mechanism seemed to be quite capable of inhibiting poliovirus infection, indicating that the intestinal receptor cell for poliovirus operates normally in kwashiorkor (B8). It is now known that polio antiliodies are mainly associated with IgA. 

Chagas disease, both the serum immunoglobulin levels and complement titers were similar to those of other uninfected subjects living in the same area. The experimental findings in C.,H mice, that thymus-dependent cell mediated immune mechanisms arc involved in controlling infection with Trypanosoma cruzi appear promising. 

B Blood and blood-forming organs 280-289 Diseases of the hlood and hlood-forming organs and certain disorders involving the immune mechanism... 

This outline is not exhaustive. For example there is an increasing awareness of the role played by infection with the human immunodeficiency virus while infiltration of the marrow with fibrous tissue or tumour cells will decrease production. In much the same way massive splenomegaly, so common in tropical Africa, sequesters significant volumes of red cells while malarial infection results in their accelerated breakdown. In some cases defects are multifactorial as in chronic lymphocytic leukaemia where infiltration decreases production, splenomegaly traps large amounts of blood while immune mechanisms lead to shortened survival or haemolysis. 

Management may on occasions have to be splenectomy but in these situations there are generally other factors. For example, in chronic lymphocytic leukaemia contributions to the thrombocytopenia that occurs from reduced production of the one hand and rapid clearance due to immune mechanisms on the other. 

Clinical expressions of cutaneous allergic reactions include eczematous, indurate-inflammatory, and urticarial eruptions. Irritant responses causing direct damage to the skin may be confused with allergic responses involving immune mechanisms. An important difference is that allergic reactions require an initial exposure to sensitize the individual dermatitis is then elicited by minimal subsequent exposure to the agent. 

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