Cystic fibrosis water

The gene defective in cystic fibrosis codes for CFTR (cystic fibrosis transmembrane condnctance regulator), a membrane protein that pumps CP out of cells. If this CP pump is defective, CP ions remain in cells, which then take up water from the surrounding mucus by osmosis. The mucus thickens and accumulates in various organs, including the lungs, where its presence favors infections such as pneumonia. Left untreated, children with cystic fibrosis seldom survive past the age of 5 years. 

Specific ion electrodes, similar in design to the glass electrode, have been developed to analyze for a variety of cations and anions. One of the first to be used extensively was a fluoride ion electrode that is sensitive to F- at concentrations as low as 0.1 part per million and hence is ideal for monitoring fluoridated water supplies. An electrode that is specific for Cl- ions is used to diagnose cystic fibrosis. Attached directly to the skin, it detects the abnormally high concentrations of sodium chloride in sweat that are a characteristic symptom of this disorder. Diagnoses that used to require an hour or more can now be carried out in a few minutes as a result, large numbers of children can be screened rapidly and routinely. 

CFTR has a single-channel conductance of about 8 pS. It is present in the apical membranes of many epithelia. Its mutation leads to the potentially lethal disease cystic fibrosis. In addition to acting as a chloride channel, CFTR is also thought to regulate, e.g., the epithelial sodium channel ENaC, a molecularly unknown outwardly-rectifying chloride channel, and possibly also potassium channels and water channels. Some of these potential regulatory processes, however, are controversial. CFTR also acts as a receptor for bacteria. 

Chloride ion-selective electrodes The most important region of application is the determination of chlorides in waters, including sea water (for a review, see [167]), in serum [110,112,371] (review in [167]) and in soil [151,219,341], The determination of chloride ions in sweat made screening for cystic fibrosis possible in new-born babies (review, [45,55a, 262]). Br , I and S " interfere in the determination of chlorides in phosphate rocks [81]. Sulphite can be determined directly using an electrode with an Hgj CI2 - HgS membrane [398] on the basis of the reaction... 

Cystic fibrosis is a life-threatening genetic disease caused by a dysfunctional cystic fibrosis transmembrane regulator, CFTR protein, which modulates salt and water transport into and out of cells. This ion-channel defect leads to poorly hydrated, thick, mucous secretions in the airways and severely impaired mucociliary func-... 

An important condition to be fulfilled in order to use the method for detection of sweat formation and its composition is that the electrodes are elec-trolytically in contact with each other. This is not a strict condition for urine detection and as an early-warning system for diabetes, because in these applications a qualitative detection is enough, and therefore one can start with dry electrodes. For diagnosis of cystic fibrosis, this is not possible because here a quantitative detection of salt concentration is expected. Therefore, one needs to start from a system with electrodes that are elec-trolytically in contact with each other right from the start of the experiment. For this purpose, water is immobilised in high-density cotton in which the conductive stainless-steel yarn electrodes are implemented. 

Chronic diseases include cystic fibrosis in which nasal mucus is thick and viscous as a result of abnormal chloride transport across the membrane of the epithelial cells, leading to reduced water secretion. Similarly, chronic sinusitis also reduces nasal mucociliary clearance due to an increase in the rheological properties of mucus. 

Genetic alterations or abnormalities of germ cells, some of which can be caused by toxicant exposure, can be manifested by adverse effects on progeny. The important health effects of these kinds of alterations may be appreciated by considering the kinds of human maladies that are caused by inherited recessive mutations. One such disease is cystic fibrosis, in which the clinical phenotype has thick, dry mucus in the tubes of the respiratory system such that inhaled bacterial and fungal spores cannot be cleared from the system. This results in frequent, severe infections. It is the consequence of a faulty chloride transporter membrane protein that does not properly transport Cl ion from inside cells to the outside, where they normally retain water characteristic of healthy mucus. The faulty transporter protein is the result of a change of a single amino acid in the protein. 

A further type of PM-located GC is gastrointestinal (GI) C-type GC that is activated by the paracrine peptide hormone guanylin. Guanylin is secreted by GI cells and resultant GC activation and cGMP elevation results in increased Cl transport via the cystic fibrosis transmembrane conductance regulator (CFTR) into the intestinal lumen with resultant increased water flow. The Escherkhia coli heat-stable enterotoxin mimics guanylin in activating this intestinal C-type GC and consequently causes diarrhoea. 

Q10 Pancreatic insufficiency occurs in approximately 80% of cystic fibrosis patients. There is a marked reduction in the water, electrolyte and enzyme content of pancreatic secretion. Because of deficient digestive enzymes, there is inadequate digestion and absorption of nutrients and some nutritional deficiency occurs. 

Qll Pancreatic enzyme secretion is greatly reduced in cystic fibrosis. Relative or total absence of pancreatic lipase results in failure of fat digestion. The undigested fat is not absorbed, remains in the intestine and is excreted in relatively large quantities. The faeces are pale, bulky, smell unpleasant, float in water and are difficult to flush. This condition is called steatorrhoea. 

Nutrient malabsorption also occurs in the genetic disease cystic fibrosis. This disease arises from a mutation in the chloride ion transporter, and results in pancreatic insufficiency as well a.s respiratory difficulties. Treatment of the malabsorption symptoms of cystic fibrosis involves supplementation with pancreatic enzymes and synthetic water-soluble versions of the fat-soluble vitamins. The labored breathing and respiratory infections due to the disease cannot be treated by dietary intervention. 

The rate of removal of mucus from the airways is determined by such factors as mucus viscosity, the amount of mucus produced, and the degree of ciliary activity. These processes may be influenced by a variety of diseases, including asthma, cystic fibrosis, and chronic bronchitis [82,83], In patients suffering from cystic fibrosis or chronic bronchitis, mucus hypersecretion is evident and mucociliary function is impaired. The failure to clear mucus from the airways leads to airway obstruction and to chronic colonization of the airways with bacterial organisms (which leads to lung infections and airway inflammation and damage). In asthmatic subjects, airway mucus is more viscous and ciliary transport mechanisms are inhibited [82,83]. In these diseases, the therapeutic objective is to improve mucus clearance from the airways. For example, aerosols of water or saline (especially hypertonic saline) promote clearance of mucus by... 

The answer is a. (Murray, pp 627-661. Scriver, pp 3897-3964. Sack, pp 121-138. Wilson, pp 287-320.) Vitamins A, D, E, and K are all fat-soluble. The physical characteristics of fat-soluble vitamins derive from the hydrophobic nature of the aliphatic chains composing them. The other vitamins listed are water-soluble, efficiently administered orally, and rapidly absorbed from the intestine. Fat-soluble vitamins must be administered intramuscularly or as oral emulsions (mixtures of oil and water). In intestinal disorders such as chronic diarrhea or malabsorption due to deficient digestive enzymes, fat-soluble vitamins are poorly absorbed and can become deficient. Supplementation of fat-soluble vitamins is thus routine in disorders like cystic fibrosis (219700), a cause of respiratory and intestinal disease that is the likely diagnosis in this child. 

Nasr SZ, O Leary MH, Hillerman C. Correction of vitamin E deficiency with fat-soluble versus water-miscible preparations of vitamin E in patients with cystic fibrosis. J Pediatr 1993 122 810-812. 

D. Because cystic fibrosis leads to pancreatic damage and diminution of the abihty to secrete HCO3 and pancreatic digestive enzymes with the result that fat and protein are absorbed poorly. Retinol is a fat-soluble vitamin that must be absorbed along with lipid micelles other fat-soluble vitamins are E, D, and K. The other vitamins hsted are water-soluble and their absorption is not significantly affected. 

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