Membrane hyperplasia

Membrane hyperplasia The proliferation rate of the SER may have developed to such an extent that cell volume grows by up to 50% this can increase the weight of the liver and cause hepatomegaly. (see chapter 11)... 

The effects of dmgs and adjuvants must be assessed, both in short-term administration and during chronic treatment. Local effects include changes in mucocihary clearance, cell damage, and irritation. Chronic erosion of the mucous membrane may lead to inflammation, hyperplasia, metaplasia, and deterioration of normal nasal function (76). 

Hepatic peroxisome proliferation, characterized by liver enlargement due to hyperplasia and hypertrophy, has been proposed as a basis for differences in species susceptibility to trichloroethylene carcinogenicity. Peroxisomes are membrane-bound organelles which contain enzymes generally involved in lipid metabolism. 

Renal effects have been observed in both male and female rats in a chronic-duration oral study. Male Fischer 344 rats exposed to 1,4-dichlorobenzene at 150 and 300 mg/kg/day for 2 years exhibited nephropathy, epithelial hyperplasia of the renal pelvis, mineralization of the collecting tubules in the renal medulla, and focal hyperplasia of the tubular epithelium. Each of these effects was associated with hyalin droplet formation. There were also increased incidences of nephropathy in female Fischer 344 rats dosed with 1,4-dichlorobenzene at 300 and 600 mg/kg/day. Histopathologically, the nephropathy was characterized by degeneration and regeneration of the tubular epithelium, tubular dilatation with attenuation and atrophy of the epithelium, granular casts in the tubules of the outer stripe of the medulla, thickening of the basement membranes, and minimal accumulation of interstitial collagen (NTP 1987). 

Pathogenesis. The clinical features of myasthenia gravis are caused by specific autoantibodies to the nicotinic acetylcholine receptor. These antibodies accelerate receptor turnover shortening their typical lifetime in the skeletal muscle membrane from aroimd 7 days to 1 day in a myasthenic. This process results in marked depletion of receptors from myasthenic skeletal muscle (about 90%) explaining its fatigability. The frequent finding of a specific haplotype (Al-B8-Dw3 HLA) in myasthenics and concurrent hyperplasia or tumours of the thymus support the autoimmune basis for the disease. 

Phenol is the common topical anesthetic for myringotomies. It is applied over the specific area of the tympanic membrane where the myringotomy is to be performed. It acts by causing instant epidermal destruction. The section of the tympanic membrane in contact with the phenol turns white owing to the anticipated proteins, indicating an anesthetic effect. Healing occurs by hyperplasia of the epithelium and connective tissue but may take some time after applications. ... 

The unwanted peripheral effects of all atropine-like drugs include flushing of the skin, dryness of the mucous membranes with fever, tachycardia, reduced salivary secretion and dryness of the mouth, drying up of the gastrointestinal secretions and decreased gastric acidity, and reduced muscle tone in the gut and constipation. Bladder tone and frequency of micturition are reduced and acute urinary retention is a risk, especially in older men with prostatic hyperplasia. Nasal, bronchial, and lacrimal secretions are reduced. 

The histologic findings in asthma consist of massive epithelial shedding, hyperplasia of smooth muscle fibers, mucus glands and goblet cells, basement membrane thickening (Brewster etal., 1990), and eosinophil infiltra-... 

Data reviewed indicate that chronic effects may be related to the changes related to irritation. Chronic exposure to skin and mucous membranes at sufficiently high levels may cause inflammation, hyperplasia,... 

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