Absorption significance

Treatments which transiently open up intercellular gaps increase absorption significantly. In the villus, the loss of apical cells may cause large gaps at the tip,... 

Henderson and Rudin111 examined the effects of water on starch-PMA and starch-g-PS extrudates of similar add-on. When immersed in water, starch-g-PS gained approximately 9% in weight and 7% in cross-section area, with essentially no water extractables. Starch-g-PMA gained 25% in weight and 50% in cross-section under the same immersion conditions. Extractables for the starch-g-PMA were 12.4%. Water absorption significantly reduced the tensile strengths of the copolymers the... 

Kreydiyyeh et al. (2001) provided scientific evidence to confirm the laxative property of parsley, as claimed in folk medicine, and explained its mechanism of action. A perfusion technique was used to measure net fluid absorption from rat colon. The addition of an aqueous extract of parsley seeds to the perfusion buffer, and the omission of sodium, both significantly reduced net water absorption from the colon, as compared with the control. Parsley, added to a sodium-free buffer, did not lead to any further significant change in water absorption as compared with parsley alone suggesting that with parsley, sodium absorption was already inhibited. Since K+ and Cl secretion depends on the activity of the NaKCl2 transporter, the latter was inhibited with furosemide, which increased net water absorption significantly. When parsley and furosemide were... 

The limestone grind aflFects the absorption significantly at SO2 concentrations above 1000 ppm. High absorption (95% ) can be achieved with an 89%-325 mesh material at 1300 ppm. 

Absorption Clindamycin is nearly completely absorbed following oral administration. Food does not affect absorption significantly. The of the antibiotic is 3 hours. 

From the above two cited examples one may evidently conclude that the tetracyclines may form stable complexes with bivalent metal ions e.g., Mg, Ca ) that would appreciably minimize the absorption from the Gl-tract. In reality, these adjuvants seen to compete with the tetracyclines for substances present in the GI-tract which might otherwise be free to complex with these antibiotics, and thus ultimately retard their absorption significantly. Of course, there is no concrete evidence which may suggest that the metal ions (Mg, Ca ) per se serve as buffers , a theoretical explanation quite often put forward in the literature. 

Bile salts have been used for centuries as digestive aids and cathartics. Their use for these purposes has become more limited recently, and this is probably appropriate until better preparations become available and indications for their administration become more clearly defined. Most commercial bile salt preparations are desiccated or crude extracts of cattle bile containing mainly unconjugated bile salts with small amounts of pigment and lipids. They are generally supplied as 0.2- or 0.3-g tablets. The customary dose is 0.4-0.6 g three times daily with meals. This is probably an inadequate dose, as will be explained later. Dehydrocholic acid, 3,7,12-triketo-5j -cholanoic acid, is oxidized cholic acid and is supplied in pure form but does not form micelles and hence probably does not assist fat absorption significantly and would be of little value for replacement therapy. Sodium dehydrocholate is supplied as a 20 % solution in ampules and is widely used to measure blood circulation times. It does not appear to be conjugated by the liver (86). 

When taken orally, saponins are absorbed rather poorly from the gut. Those that are absorbed are often in the aglycone form, following interaction with bacteria in the large bowel. The slow rate of absorption significantly slows the rate of haemolysis and associated toxicity (Mills and Bone 2000 43). Saponins are regnlarly consnmed in everyday foods such as cereals (Osbourn 2003) and, with few exceptions, do not demonstrate toxic effects in humans. 

Abrams and Grundy found that hypothyroid patients had a virtually normal cholesterol absorption, but that the absorbed fraction was lowered after treatment with thyroxin[127]. The authors speculated that the accelerated transit time induced by hyperthyroidism could be responsible for the reduced cholesterol absorption. To similar conclusions came Carulli et al. who studied cholesterol absorption and small bowel transit both in hyper and in hypothyroid patients[128]. The authors found that thyroid hyperfunction was associated with a very rapid intestinal transit and with a cholesterol absorption significantly lower than normal in contrast, hypothyroid patients had a very slow transit time and in 3 out of 5 cholesterol absorption was at the upper limits of normal. Furthermore, in 4 hyperthyroid patients with a low cholesterol absorption the absorbed fraction rose sharply after antithyroid therapy[129]. 

The moisture absorption eapability of a polyacrylate-type superabsorbent polymer is lower than that of inorganic moisture absorption agents, such as silica gel. In addition, moisture absorption significantly increased as the water vapor pressure increased. This is due to the excellent water absorption capability of the superabsorbent polymers. Hence, superabsorbent polymers are especially useful for moisture absorption at high humidity. Furthermore, by adding a moisture absorption agent, such as calcium chloride, a eompound that has lower saturation... 

Figure 10. Sitostanol administered in lecithin micelles (vesicles) is more effective than crystalline (powdered) lecithin at reducing cholesterol absorption. Significantly different from placebo P=0.01, P=o.003. Taken from Ostlund et al (1999). Reproduced with permission by the American Journal of Clinical Nutrition. Am. J. Clin. Nutr. American Society for Clinical Nutrition.

Biodegradable plastics based on soy protein were prepared with glycerol as a plasticizer and compounded wi different additives such as polycaprolactone and zinc stearate as well as heat treated at various temperatures after the injection molding process in order to characterize base material strength and the effect of water absorption. The results indicated that the polycaprolactone and, respectively a medium to high heat treatment enhanced the tensile strength and decreased the water absorption significantly. 

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