Formation of granulation tissue

Most of the techniques in current use are derived from the original method described by Meier, Schuler and Desaulles in 1950 . When pellets of cotton-wool, cellulose sponge or similar material are implanted subcutaneously into the abdomen of the rat and left for 7 days, granulation tissue forms around and into the pellets. After 7 days the animals are killed and the pellets, together with the granulation tissue, are removed and dried to 

A valid criticism of the technique (similar to that mentioned by Lorenz for rat-paw oedema) has recently been made by Gygielman and Robson , who observed that anti-inflammatory activity, determined by the cotton pellet test, of a group of substances derived from liquorice seems to be associated with irritant effects at the site of injection. They proceeded to show that the injection of known irritants such as antimony potassium tartrate and croton oil produces a significant reduction in granulation tissue. Robinson and Robson suggested, in the light of further experiments, that the reason for this is that an anti-inflammatory factor is produced at the site of implantation of the irritant substance. 

A somewhat different granuloma pellet technique has been described in which a piece of non-resorbable plastic sponge is inserted subcutaneously into rats, and the exudate and leucocytic infiltration into it are measured over the next 5 hours .  

This technique was first devised by Selye and modified by Robert and Nezamis . It has been used extensively for testing anti-inflammatory corticosteroids, but may also be used for assaying the more potent nonsteroidal anti-inflammatory antirheumatic compounds. 

A subcutaneous dorsal pouch is produced in the rat by the injection of 25 ml. of air into this space is injected 0-5-1 ml. of 1 per cent croton oil in cotton-seed or similar oil. Over the following days a haemorrhagic exudate accumulates in the pouch, the wall of which becomes thickened and granulomatous. To increase the exudation of fluid into the cavity the air may be withdrawn 48 hours after the formation of the pouch. The animals are killed 

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Cliuical pharmacology Native PDGF is a growth factor derived from blood platelets that mediates tissue repair. Becaplermin has biological activity similar to that of endogenous PDGF it promotes the chemotactic recruitment and prohfera-tion of cells involved in wound repair— fibroblasts, smooth muscle cells, monocytes, and neutrophils—and enhances the formation of granulation tissue. 

These kinds of wounds will be closed in the secondary healing processes, where the formation of granulation tissue first takes place. Covering with epithelium is the final stage of wound healing. Often such secondary healing processes take a long time and require a lot of material [ 126]. 

Wound healing effect of carnosine is potentiated by zinc [35,91]. Its mechanism probably related to ability of carnosine to support functional activity of lymphocytes [61], to reveal the immunomodulating activity depending on age of animals and concentration of carnosine [86,92], to neutralize ROS formed in the inflammatory area. In some cases, increased formation of granulating tissues was noted which stimulated healing of damaged surface because of protein synthesis activation [86,88]. 

Collagenase contributes to the formation of granulation tissue and subsequent epithelialization of dermal ulcers and severely burned areas. It is indicated in the debriding chronic dermal ulcers and severely burned areas. 

The development of artificial wound coverings has received much attention. The major requirements for such coverings are protection from microbial attack from the environment, optimal water permeability, capability of adhering well to the wound, and ready removability without causing tissue damage. Other important factors are prevention of excessive formation of granulation tissue and optimal elasticity to facilitate an intimate cover of the wound. 

Therapy postoperative intestinal dystonia, paralytic ileus, for promoting the formation of granulation tissue and epithelization... 

The wide range of practical medical applications of hyaluronan continues to be based upon its anti-inflammatory, disinfectant and wound healing effects. HA promotes epithelial regeneration prevents the formation of granulation tissue, adhesions and scars reduces swelling and itching normalizes blood circulation promotes scarring of venous ulcers and protects internal eye tissue [24]. 

Lloyd-Owen SJ, Donaldson GC, Ambrosino N, et al. Patterns of home mechanictil ventilation use in Europe results from the Eurovent survey. Eur Respir J 2005 25 1025-1031. Yaremchuk K. Regular tracheostomy tube changes to prevent formation of granulation tissue. 

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