Gastrointestinal Tract Pathology

Clouston, A.D., Timely topic premahgnant lesions associated with adenocarcinoma of the upper gastrointestinal tract. Pathology, 33, 271-277, 2001. 

M. O. Blackstone, Endoscopic Interpretation—Mormal and Pathologic Appearances of the Gastrointestinal Tract, Raven Press, New York, 1984. 

Hill M Normal and pathological microbial flora of the upper gastrointestinal tract. Scand J Gastroenterol Suppl 1985 111 1-6. 

Smooth muscle is distributed throughout the body, largely around hollow structures such as blood vessels, the gastrointestinal tract and the genitourinary system. Normal function requires that the smooth muscles contract and relax at appropriate times, and abnormalities of contraction underlie such important pathologies as hypertension, incontinence and abnormal childbirth. Since contraction is initiated by an increase of cytoplasmic Ca2+ concentration then normal function requires appropriate Ca2+ handling. 

A high rate of ethanol consumption can lead to inhibition of gastric secretion and irritation of the gastric mucosa. Ethanol irritates the entire gastrointestinal tract, which may lead to constipation and diminished absorption of nutrients. Other pathological effects include pancreatitis and peripheral neuropathy. Severe gonadal failure is often found in both men and women, accompanied by low blood levels of sex hormones. 

Probably the vanadium compound to which people are most likely to be exposed is vanadium pentoxide, V205. Exposure normally occurs via the respiratory route, and the pulmonary system is the most likely to suffer from vanadium toxicity. Bronchitis and bronchial pneumonia are the most common pathological effects of exposure skin and eye irritation may also occur. Severe exposure can also adversely affect the gastrointestinal tract, kidneys, and nervous system. 

D-Pantolactone (Figure 6.3.1) is an important intermediate in the production of d-pantothenic acid, also called vitamin B5. Deficiency of pantothenic acid can result in symptoms such as pathological changes of the skin and mucosa, disorders in the gastrointestinal tract and nervous system, organ changes, and hormonal disorders. Pantothenic acid is used mainly in feed for chicken and pigs and also as a vitamin supply in human nutrition. Its commercial form, the calcium salt, is produced worldwide on a multi-thousand ton scale. 

Eosinophils are leukocytes that contain characteristic cationic proteins in their granules that bind the acidic dye eosin. In contrast to neutrophils, eosinophils are minority cells in the blood and are predominantly tissue-dwelling cells found at sites in contact with the environment the mucosal surfaces of the lung, gastrointestinal tract, and genitourinary tract. Selective accumulation of eosinophils, as opposed to neutrophils, is one of the major pathological features of the inflammatory response to infection with parasitic helminths, and in several diseases such as asthma, allergic rhinitis, and atopic dermatitis. A key step in leukocyte recruitment is the local production of chemoattractant molecules that orchestrate the adhesive interactions between leukocytes and the vascular endothelium. 

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