Fibrous lesions

Severe liver histopathologies extensive fibrous lesions and hepatocyte necrosis of rainbow trout [57]... 

Lipid Fatty streak (weight %) Intermediate lesion (weight %) Fibrous lesion (weight %) Advanced lesion (weight %)... 

THERAP cat (VET) Actinobacillosis. actinomycosis. Expectorant. Has been used for ringworm, hyperplastic fibrous lesions, paraplegia from pachymeningitis of dogs. 

The commonest fibrous lesion of bone is the fibrous cortical defect and the histologically identical but larger nonossifying fibroma. Both lesions are seen in childhood and adolescence, slightly more common in boys, with a predilection for the long bones around the knee. Fibrous cortical defects are seen in up to 30% of the normal population under the age of 15 years and... 

Metanephric stromal tumor was more recently described (Fig. 24.20) (Argani and Beckwith 2000). Mean patient age at diagnosis is 2 years. Gross examination typically revealed a fibrous lesion centered in the renal medulla containing smooth-walled cysts. Metanephric stromal tumor is histologically identical to the stromal component of metanephric adenofibroma. Patients may be treated with surgical excision alone. 

Bone defects surgically produced in sheep and rabbit models, have been treated with freeze dried methylpyrrohdinone chitosan [334-336]. hi view of improving bone tissue reconstitution with chitosan associated with calcium phosphate. Microscopic and histological analyses showed the presence of an osteogenic reaction moving from the rim of the surgical lesion toward the center. In control lesions, dense fibrous tissue, without the characteristic histoarchitecture of bone was observed. 

Much less commonly, acne scarring may become thickened (hypertrophic or keloidal) rather than atrophic. Hypertrophic scars represent the presence of excessive fibrous tissue with marked vascularization. While hypertrophic scars tend to maintain the same size as the initial inflammatory lesion, keloids extend beyond the dimension of the original acne lesion. 

At cellular level each stage of atheroma development is accompanied by the expression of specific glycoproteins by endothelial cells which mediate the adhesion of monocytes and T-lymphocytes. Their recruitment and migration is triggered by various cytokines released by leukocytes and possibly by smooth muscle cells. Atheroma development continues with the activation of macrophages, which accumulate lipids and become, together with lymphocytes, so-called fatty streaks. The continuous influx, differentiation and proliferation finally leads to more advanced lesion and to the formation of the fibrous plaque. ... 

Lipid-laden macrophages, smooth muscle cells, and necrotic debris from the death of foam cells accumulate in the subendothelial space, leading to enlargement of the fatty streak. A collagen matrix forms a fibrous cap that covers the lipid core of the lesion to establish a fibrous plaque called an atherosclerotic plaque. Initially, the diameter of the coronary artery lumen is... 

In Apo E-deficient animals fed a normal chow diet, fatty streaks are first observed in the proximal aorta at 10 to 12 weeks (15). The xanthoma that forms in the intima contains foam cells and is often called the early atherosclerotic lesion and is critically dependent on monocytes. Smooth muscle cells (SMCs) arrive in the intima at approximately 15 weeks and form a fibrous cap around 20 weeks (16). By 36 weeks, lumen narrowing occurs in the external branches of the carotid artery (incidence -75%), but the lumen size is maintained in the aorta. Lumen narrowing, or stenosis, does not correlate with plaque size but... 

IL-6 participates in both atherogenesis and inflammatory processes. In one interesting mouse model that was double deficient at the apoE and IL-6 loci, animals displayed similar hypercholesterolemia compared to apoE-null mice, but disclosed larger and more calcified lesions at 1 year of age (Klinge 2001). Thus, IL-6 appears to be involved at the fibrous plaque stage of the atherosclerotic process. Moreover, IL-6 is a key factor in the generation of the hepatic acute-phase response and so increases the levels of CRP, fibrinogen, platelet... 

As Lp(a) also binds to glycoprotein-IIb on platelets (M9), its role in formation of fibrous plaque lesions could also exist by this route. 

G, alpha Insertions/dele- syndrome fibrous dysplasia of bone cafe-au-lait skin lesions sexual precocity pituitary, thyroid, or adrenal tumors Albright s hereditary with constitutive cAMP production Inactivating G a (86-89)... 

The interactions of these cells with T lymphocytes also in the lesion and the overlying endothelium can lead to a massive flbroproliferative response over which connective tissue from smooth muscle cells form a fibrous cap. This covers the advanced lesion or fibrous plaque of atherosclerosis, deeper portions of which consist of macrophages, T lymphocytes, smooth muscle cells, connective tissue, necrotic debris and varying amounts of lipids and lipoproteins. 

Exposure of the lungs to xenobiotics may result in a number of disease conditions including bronchitis, emphysema, asthma, hypersensitivity pneumonitis, pneumoconiosis, and cancer. During repair, damaged lung alveolar epithelium may be replaced by fibrous tissue that does not allow for gas exchange, which intensifies the damage caused by the initial lesion. 

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