Excretion faecal

Excretion Faecal (exclusively) Urinary (mainly) bacterial products may appear in faeces... 

Lipophilicity Frotein binding (%) Metabolism Renal excretion (%) Faecal excretion (%)... 

Most of the calcium that is lost from the body is excreted in the faeces, this being mainly unabsorbed dietary calcium. However, the digestive secretions all contain small amounts of calcium, and individuals on a calcium-free diet continue to excrete faecal calcium. The normal daily excretion is of the order of 0-1-0-3 g (2-5-7-5 mmol). The quantity of phosphorus excreted daily varies with the dietary intake. As with calcium an appreciable proportion of ingested phosphorus remains unabsorbed and is eliminated in the faeces. Phosphorus is also excreted in the urine, almost entirely in the form of orthophosphates (e.g. NaH2P04 and Na2HP04). Their role in the regulation of acid-base balance is discussed on page 395. Urinary excretion of phosphate is increased in hyperparathyroidism. 

Human exposure to environmental contaminants has been investigated through the analysis of adipose tissue, breast milk, blood and the monitoring of faecal and urinary excretion levels. However, while levels of persistent contaminants in human milk, for example, are extensively monitored, very little is known about foetal exposure to xenobiotics because the concentrations of persistent compounds in blood and trans-placental transmission are less well studied. Also, more information is needed in general about the behaviour of endocrine disruptive compounds (and their metabolites) in vivo, for example the way they bind to blood plasma proteins. 

Thus, it is apparent that soya, some soya products and linseed oil influence blood lipid levels, particularly cholesterol and LDL cholesterol. While the extent of the reduction appears to largely depend on an individual s initial serum cholesterol level, the maximum reductions observed are of the order of 10-15%. For hyperlipidemic individuals this may not be a marked reduction, but such an effect on the general population may well have a beneficial effect on the overall incidence of cardiovascular disease and atherosclerosis. The possibility that non-phytoestrogenic dietary components may contribute to the hypocholes-terolemic properties cannot, however, be discounted. Indeed, certain types of dietary fibre have been shown to have a hypolipidemic effect via their ability to increase faecal excretion rates. 

Faecal excretion of vaeeine virus will oeeur and may last for up to 6 weeks. Such released virus will spread to elose eontaets and infect/(re)immunize them. Since the introduction of OPV, notifications of paralytic poliomyelitis in the UK have dropped speetacularly. From 1985-95, 19 of the 28 notified cases of paralytic poliomyelitis were associated with vaeeine strains (14 reeipients, 5 contacts). Vaccine-associated poliomyelitis may occur through reversion of the attenuated strains to the virulent wild-... 

Recently, some of the specific faecal bacteria involved in the metabolism of dietary isoflavonoids were isolated (Hur et al., 2000). They have been shown to selectively convert genistin and daidzin to their respective aglycones. One of the isolated bacteria, under anoxic conditions, was further shown to metabolise genistein and daidzein to their respective dihydroxy-genistein and dihydroxy-daidzein. In the case of lignans, enterodiol and enterolactone were shown to be excreted in vivo only in rats harbouring a gut microflora (Rowland et al, 1999). 

Ganji, V., and Kies, C. V. (1994). Psyllium husk fiber supplementation to soybean and coconut oil diets of humans Effect on fat digestibility and faecal fatty acid excretion. Eur. J. Clin. Nutr. 48, 595-597. 

After either oral or intravenous administration of [ Cjondansetron to rats the majority (about 80 %) of the radioactive dose is voided in the faeces, the remainder of the dose being excreted in the urine. In the dog, faecal elimination accounts for about half of the dose and is independent of the route of administration. Evidence from animals with cannulated bile-ducts indicates that the major route of excretion is via the bile. In both species, less than 5 % of the dose is excreted unchanged in urine, suggesting that extensive metabolism of ondansetron occurs. 

They are useful only in hyperlipoproteinemias involving elevated levels of LDL i.e. type Ila, lib and V. They are basic ion exchange resins. They are neither digested nor absorbed in the gut. They bind bile acids in intestine and interrupt their entero-hepatic circulation, leading to increased faecal excretion of bile salts and cholesterol. There is increased hepatic conversion of choles-terol to bile acids. More LDL receptors are expressed on liver cells leading to increased clearance of IDL, LDL and indirectly of VLDL. 

Lengsfeld, H., Fleury, A., Nolte, M., Piquerez, J. C, Hadvary, P., and Beglinger, C. (1999). Effect of orlistat and chitosan on faecal fat excretion in young healthy volunteers. Obes. Res. 7(Suppl. 1), 50S. 

Tissue distribution was examined at five time points, with separate determinations of total 4C, tris(2,3-dibromopropyl) phosphate and bis(2,3,-dibromopropyl) phosphate. The results confirmed the rapid disappearance of tris(2,3-dibromopropyl) phosphate, this being detected only at 5 and 30 min. Bis(2,3-dibromopropyl) phosphate was the major component in blood, lung, muscle and fat and had a long elimination period. At five days after dosing, there was significant retention of in the kidney, this comprising various polar components with some bis(2,3-dibromopropyl) phosphate also detected. The extensive biliary excretion of tris(2,3-dibromopropyl) phosphate-related radioactivity and low faecal elimination of the radiolabel indicate that enterohepatic circulation contributes to the retention of in the body (Lynn et al., 1982). 

The percutaneous absorption of acrylic acid has also been examined in rats and mice. After application to the skin, approximately 73% of a dose of approximately 17 mg/kg bw (501 pg/cni-) was lost by evaporation (Winter Sipes, 1993). Of the remainder, 6% of dose w as retained on or in the skin from the site of application and 16% was exhaled as 003. Urinary and faecal excretions w ere very minor routes (less than 1% and 2-4% of the dose, respectively). 

Finally, vaccination of cattle with S. bovis GST elicited an anti-fecundity effect, manifest as reduced faecal egg excretion and tissue egg but not adult worm burden (Bushara et al., 1993). Conversely, vaccination of goats (Boulanger et al., 1 994) and sheep (Boulanger et al., 1999a) resulted in reduced worm burdens but no anti-fecundity effect. 

N-(2,3-Dimercaptopropyl)phthalamidic acid (41, DMPA) has been shown to form relatively stable complexes with cadmium, zinc and mercury312. DMPA has also been shown to enhance faecal and urinary excretion of mercury in mice and arsenic in mice and rabbits. For the decorporation of arsenic, taken in as arsine, the administration of 3-(tolylthio)propane-l, 2-dithiol (42) has been proposed in the USSR313. ... 

Pluim, H.J., Wever, J., Koppe, J.G., Slikke, J.W., Olie, K., 1993. Intake and faecal excretion of chlorinated dioxins and dibenzofurans in breast-fed infants at different ages. Chemosphere 26, 1947-1952. 

J.L. Hambrook, J.M. Harrison, D.J. Howells and C. Schock, Biological fate of sulfur mustard (l,l -thiobis(2-chloroethane)) urinary and faecal excretion of 35S by rat after injection or cutaneous application of 35S-labelled sulfur mustard, Xenobiotica, 22, 65-75 (1992). 

During an acute attack, a fresh urine sample which has been protected from light should be sent to a specialist laboratory to be tested for aminolaevulinic acid and porphobilinogen concentrations. If urinalysis confirms raised urinary excretion of aminolaevulinic acid and porphobilinogen, an analysis of faecal porphyrins can be used to identify the specific porphyria. In acute intermittent porphyria faecal porphyrin levels are generally normal. 

Malabsorption is defined as an inadequate assimilation of dietary substances due to defects in digestion, absorption or transport. Malabsorption can affect macronutrients (proteins, carbohydrates, fats), micronutrients (vitamins, minerals) or both, causing excessive faecal excretion and producing nutritional deficiencies and GI symptoms. Digestion and absorption occur in three phases, namely (i) the intra-lumen hydrolysis of fats, proteins and carbohydrates by enzymes, and emulsification by bile salts, (ii) digestion by brush-border enzymes and uptake of end-products and (iii) lymphatic transport of nutrients. Malabsorption can occur when any of these phases is impaired. 

Steatorrhoea is the formation of non-solid faeces. Floating stools, due to excess fat, are oily in appearance and foul smelling. There is increased fat excretion, which can be measured by determining the faecal fat level. Possible biological causes can be lack of bile acids (due to liver damage or hypolipidaemic drugs), defects or a reduction in pancreatic enzymes (lipase), and defective mucosal cells. The absence of bile acids will cause the faeces to turn grey or pale. 

Absorption of vitamin B12 can be investigated in several ways after oral delivery of radioactive vitamin B12 (e.g. containing Co) and subsequent measurement of radioactivity in faecal excretion, whole body counting or liver uptake, plasma radioactivity or the popular Schilling test. For the Schilling test, urinary excretion of radioactive vitamin B12 is measured 24 h following oral delivery, and impaired absorption may indicate intrinsic factor deficiency bacterial colonization of the small intestine (stagnant gut syndrome) or ileal disease. 

Tibolone does not undergo enterohepatic circulation. Excretion occurs mainly via the faecal route, with urinary excretion accounting for the remainder. 

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