Mucositis

Diarrhea is a common problem that is usually self-limiting and of short duration. Increased accumulations of small intestinal and colonic contents are known to be responsible for producing diarrhea. The former may be caused by increased intestinal secretion which may be enterotoxin-induced, eg, cholera and E. col] or hormone and dmg-induced, eg, caffeine, prostaglandins, and laxatives decreased intestinal absorption because of decreased mucosal surface area, mucosal disease, eg, tropical spme, or osmotic deficiency, eg, disaccharidase or lactase deficiency and rapid transit of contents. An increased accumulation of colonic content may be linked to increased colonic secretion owing to hydroxy fatty acid or bile acids, and exudation, eg, inflammatory bowel disease or amebiasis decreased colonic absorption caused by decreased surface area, mucosal disease, and osmotic factors and rapid transit, eg, irritable bowel syndrome. 

Allergic Seasonal or Perennial Rhinoconjunctivitis. Histamine can cause all pathologic features of allergic rhinitis (35—37), with the exception of late-phase inflammatory reactions. Pmritus is caused by stimulation of receptors on sensory nerve endings prostaglandins (qv) may also contribute. Sneering, like pmritus, is an H -mediated neural reflex and can also be mediated by eicosanoids. Mucosal edema, which manifests as nasal... 

Calcium is absorbed from the intestine by facilitated diffusion and active transport. In the former, Ca " moves from the mucosal to the serosal compartments along a concentration gradient. The active transport system requires a cation pump. In both processes, a calcium-binding protein (CaBP) is thought to be required for the transport. Synthesis of CaBP is activated by 1,25-DHCC. In the active transport, release of Ca " from the mucosal cell into... 

Iron. The total body content of iron, ie, 3—5 g, is recycled more efficientiy than other metals. There is no mechanism for excretion of iron and what Httie iron is lost daily, ie, ca 1 mg in the male and 1.5 mg in the menstmating female, is lost mainly through exfoHated mucosal, skin, or hair ceUs, and menstmal blood (74—76). Common food sources rich in iron and other trace elements are Hsted in Table 10. 

SCE protects mice from G1 death after kradiation and increases the number of surviving mucosal crypt stem cells (186) in a manner similar to lL-1. 

Dactinomycin, an antineoplastic dmg, was discovered in 1943 and is made in rather pure form by StreptomjcesparvuUus. Dactinomycin has some bacteriostatic antibacterial and antifungal activity, but high toxicity limits its use to antineoplastic therapy. It may be used alone or with other antineoplastics, with or without surgery and synergistic x-ray therapy. Dose limiting bone marrow toxicity may result in low white cell and platelet count. Intestinal mucosal damage also occurs. Reviews of more detailed chemotherapeutic information are available (217—222). 

Oral mucosal membranes provide a port for systemic therapy as weU. Nitroglycerin sublingual tablets (Nitrostat) abort acute mgina attacks methyl-testosterone [58-18-4] buccal tablets (Android 5) are indicated for testosterone [58-22-0] replacement therapy (39) md nicotine [54-11-5] gum (Nicorette) aids in smoking cessation. 

Fiber components are the principal energy source for colonic bacteria with a further contribution from digestive tract mucosal polysaccharides. Rate of fermentation varies with the chemical nature of the fiber components. Short-chain fatty acids generated by bacterial action are partiaUy absorbed through the colon waU and provide a supplementary energy source to the host. Therefore, dietary fiber is partiaUy caloric. The short-chain fatty acids also promote reabsorption of sodium and water from the colon and stimulate colonic blood flow and pancreatic secretions. Butyrate has added health benefits. Butyric acid is the preferred energy source for the colonocytes and has been shown to promote normal colonic epitheUal ceU differentiation. Butyric acid may inhibit colonic polyps and tumors. The relationships of intestinal microflora to health and disease have been reviewed (10). 

The use of a bioadhesive, polymeric dosage form for sustained dehvery raises questions about swallowing or aspirating the device. The surface area is small, and patient comfort should be addressed by designing a small (less than 2 cm ), thin (less than 0.1 mm (4 mil) thick) device that conforms to the mucosal surface. The buccal route may prove useful for peptide or protein dehvery because of the absence of protease activity in the sahva. However, the epithelium is relatively tight, based on its electrophysiological properties. An average conductance in the dog is 1 mS/cm (57) as compared to conductances of about 27 and 10 mS/cm in the small intestine and nasal mucosa, respectively (58,59) these may be classified as leaky epitheha. 

Finer particles ( < 3 pm), termed respirable particles, pass beyond the ex-trathoracic airways and enter the tracheobronchial tree. Impaction plays a significant role near the tracheal jet, but sedimentation predominates as the effects of rapid conduit expansion dampen in the distal trachea and beyond. Sedimentation occurs when gravitational forces exerted on a particle equal drag forces, i.e., when particle velocity falls to u . As mean inspiratory air-stream velocity gradually declines along the tracheobronchial tree, particle momentum diminishes and 0.5-3 pm MMAD particles settle out of the airflow and onto mucosal surfaces. 

Cole, P. (1954). Respiratory mucosal vascular responses, air conditioning and thermoregulation./. Laryngol. Otol. 68, 613-622. 

Paulsson, B., Bende, M., and Ohim, P. (1985). Nasal mucosal blood flow at rest and during exercise. Acta Otolaryngol. (Stockh.) 99, 140-143. 

Proctor, D. F., Andersen, 1 and Lundqvist, G, R. (1977a). human nasal mucosal function at controlled temperatures. Respiration Physiology 30, 109-124. 

FIGURE 10.16 The H+,lO-ATPase of gastric mucosal cells mediates proton transport into the stomach. Potassimn ions are recycled by means of an associated K /Cl cotransport system. The action of these two pnmps results in net transport of and Cl into the stomach. 

Schleim-igkelt, /. sliminess, mucosity. -mem-bran /. mucous membrane, -pilz m. slime fxmgus, sHme mold (Myxomycetea). 

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