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Results 351 - 400 of 1180
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Wang L F - - 1998
Gymnemic acid, a mixture of triterpene glycosides extracted from the leaves of Gymnema sylvestre, is known to inhibit the intestinal absorption of glucose in human and rats. This work examined the effect of gymnemic acid on oleic acid absorption by the method of intestinal perfusion in rats. The results showed ...
Jeppesen P B - - 1998
BACKGROUND: Medium chain C8-C10 triglycerides (MCTs) improve fat absorption in short bowel patients. Effects on overall energy absorption remain unknown. AIMS: To determine whether MCTs and medium chain fatty acids (MCFAs) are absorbed in the colon like the short chain fatty acids (SCFAs) or are lost in faeces similarly to ...
McCollum M Q - - 1998
To define the interactions between the absorption of glycyl-L-sarcosine (Gly-Sar; .1 mM) and glycine, L-methionylglycine, glycyl-L-leucine, L-carnosine, or L-methionylglycyl-L-methionyl-L-methionine (each at 5 mM), ovine omasal epithelium was collected from eight wethers (average BW=69+/-8.2 kg) and mounted in parabiotic chambers. [1,2]-[14C]Glycyl-L-sarcosine was used as a marker to monitor the presence of ...
Cappelli G - - 1998
To reduce the level of contamination by bacterial products, ultrafiltration systems have been introduced and validated for their capacity to block the passage of bacterial components reactive to the limulus amoebocyte lysate (LAL) test. In this study, the absorptive capacity of polysulfone membranes undergoing disinfection cycles with free chlorine and ...
Wu G - - 1998
The small intestine is not only responsible for terminal digestion and absorption of nutrients, but it also plays an important role in catabolism of arterial glutamine and dietary amino acids. Most of glutamine and almost all of glutamate and aspartate in the diet are catabolized by small intestinal mucosa, and ...
Han H - - 1998
PURPOSE: General use of nucleoside analogues in the treatment of viral infections and cancer is often limited by poor oral absorption. Valacyclovir, a water soluble amino acid ester prodrug of acyclovir has been reported to increase the oral bioavailability of acyclovir but its absorption mechanism is unknown. This study characterized ...
Noy Y - - 1998
1. Routes of yolk utilisation and some aspects of intestinal digestion and absorption were determined in the hatching poult and compared to the chick. 2. Transfer from yolk to blood was observed pre-hatch and up to 72 h post-hatch. From hatch the transport pattern was similar to the chick. 3. ...
Wester R C - - 1998
Human risk assessment for topical exposure requires percutaneous absorption data to link environmental contamination to potential systemic dose. Human absorption data are not readily available, so absorption models are used. In vitro diffusion systems are easy to use but have proved to be somewhat unreliable and are not validated to ...
Lindahl A - - 1998
The purpose of this study was to investigate the mechanisms of transport of fluvastatin across the intestinal mucosa in various regions of the intestine in the rat. In-situ single-pass perfusions of the jejunum, ileum and colon were performed and the effective permeability (Peff) of fluvastatin, antipyrine and D-glucose were assessed ...
Tappenden K A - - 1998
Intestinal adaptation is a complex physiologic process that is not completely understood. Intravenous short-chain fatty acids (SCFAs) enhance intestinal adaptation after 80% enterectomy in rats. The purpose of this study was to examine rapid responses to SCFA-supplemented total parenteral nutrition (TPN) in the normal small intestine. After jugular catheterization, 31 ...
Postlethwait E M - - 1998
Recent evidence suggests that inhaled ozone (O3) does not induce toxicity via direct epithelial interactions. Reactions with epithelial lining fluid (ELF) constituents limit cellular contact and generate products, including lipid ozonation products, postulated to initiate pathophysiological cascades. To delineate specific aspects of lipid ozonation product formation and to estimate in ...
Homan R - - 1998
Cholesterol absorption from bile acid micelles is suppressed by phosphatidylcholine (PC) in the micelles. The effects of micellar phospholipid composition on absorption, metabolism, and secretion of lipids were examined in Caco-2 cells incubated with micelles composed of taurocholic acid, cholesterol, oleic acid, monooleoylglycerol, and phospholipid. Significant amounts of all micelle ...
Jørgensen J - - 1998
BACKGROUND: Current knowledge on the colonorectal absorption of medium-chain fatty acids is limited. The purpose of the present study was to evaluate and compare the human rectal absorption of short- and medium-chain C2-C10 fatty acids in healthy volunteers. METHODS: Dialysis bags containing 20 mmol x l(-1) of the fatty acids ...
Cook S I - - 1998
Short chain fatty acids (SCFAs) have been the subject of much research over the past few decades. They play a vital role in maintenance of colonic integrity and metabolism. They are produced when dietary fibre is fermented by colonic bacteria. SCFAs are avidly absorbed in the colon, at the same ...
Rompel A - - 1998
The sulfur K-edge x-ray absorption spectra for the amino acids cysteine and methionine and their corresponding oxidized forms cystine and methionine sulfoxide are presented. Distinct differences in the shape of the edge and the inflection point energy for cysteine and cystine are observed. For methionine sulfoxide the inflection point energy ...
Sinko P J - - 1998
The mechanism of intestinal transport of valacyclovir (VACV), the L-valyl ester prodrug of acyclovir, was investigated in rats using an in situ intestinal perfusion technique. VACV demonstrates an oral bioavailability that is three to five time greater than acyclovir, concentration dependent, and saturable in humans. Homogenate and perfused buffer stability ...
Urdaneta E - - 1998
Fluoxetine is one of the most widely used antidepressants and nowadays it is also being used to manage obesity problems. In our laboratory we demonstrated that the drug inhibited sugar absorption (Monteiro et al. 1993). The aim of the present work was to determine the effect of fluoxetine on intestinal ...
Pflugmacher S - - 1998
The metabolism of xenobiotics has mainly been investigated in higher plant species. We studied them in various marine macroalgae of the phyla Chlorophyta, Chromophyta, and Rhodophyta. Microsomes contained high oxidative activities for known cytochrome (Cyt) P450 substrates (fatty acids, cinnamic acid, 3- and 4-chlorobiphenyl, 2, 3-dichlorobiphenyl, and isoproturon; up to ...
Jung Y J - - 1998
Dextran-5-aminosalicylic acid ester (dextran-5-ASA) was synthesized as a colon-specific prodrug of 5-aminosalicylic acid (5-ASA) which is active against inflammatory bowel diseases. Chemical stability of dextran-5-ASA in the bath of pH 1.2 or 6.8 was investigated at 37 degrees C for 6 hrs, and 5-ASA was not released on such conditions. ...
Thompson J S - - 1998
Extensive resections of the distal small intestine are associated with motor disruption in the proximal remnant. Luminal contents such as bacteria and short-chain fatty acids may play a role. We evaluated the effect of bypass of the ileocecal junction (ICJ) on the motor response to a 50% distal resection. Thirty-five ...
Kudoh K - - 1998
The effects of water-soluble and -insoluble indigestible saccharides (IDS) on immune responses of the intestinal tract were studied. Male 4-week-old Sprague Dawley rats were fed for three weeks on diets containing several kinds of IDS at 5%. The results revealed that the proportion of kappa-light chain and IgA-presenting lymphocytes in ...
Farrugia G - - 1998
BACKGROUND: Flufenamic acid, a fenamate, has been shown to alter markedly the membrane potential of small intestinal smooth muscle and increase intracellular calcium in single cells. AIMS: To determine the effects of flufenamic acid on myoelectrical motor activity and gastrointestinal transit in the intact animal. METHODS: Myoelectrical motor activity was ...
Fasick J I - - 1998
The absorption maxima of both rod and cone visual pigments of the bottlenose dolphin (Tursiops truncatus) are blue-shifted relative to those of terrestrial mammals. A comparison of the sequence of the dolphin rod photopigment gene with that of the bovine rod suggests that, fo the 28 nonidentical amino acids, three ...
Leone-Bay A - - 1998
Ten N-acylated, non-alpha-amino acids have been prepared as oral delivery agents and used to demonstrate the oral delivery of heparin in vivo in rats and primates. Following the oral administration of solutions containing a combination of heparin and a delivery agent to rats or primates, significant plasma heparin concentrations were ...
Staud F - - 1998
The aim of the present study was to evaluate the transfer of N-acetyl-p-aminobenzoic acid (AcPABA) across the rat term placenta and the rat small intestine and to compare it with that of its parent drug p-aminobenzoic acid (PABA). Umbilical perfusion of the rat term placenta was used to determine the ...
van Beers-Schreurs H M - - 1998
The effect of weaning on the absorptive capacity of the large intestine (LI) of weaned and unweaned pigs for short chain fatty acids (SCFA), sodium, potassium, and water has been determined by perfusion studies. Ligated loops were formed at four sites in the LI. In both groups the rate of ...
Lindmark T - - 1998
Medium chain fatty acids (MCFAs) are used to enhance the permeability of mucosal tissues to hydrophilic drugs, but their mechanism of action is largely unknown. In this study, the absorption-enhancing effects of the sodium salts of two MCFAs, capric acid (C10) and lauric acid (C12), were studied in monolayers of ...
Brayden D - - 1997
PURPOSE: The effects of sodium N-[8-(2-hydroxybenzoyl)amino]caprylate (SNAC) on heparin intestinal absorption were studied using rat in situ ileal and colonic instillations and Caco-2 monolayers. METHODS: The flux of heparin was tested in the following groups: i) heparin alone, ii) heparin in the presence of SNAC, iii) heparin in the presence ...
MacRae J C - - 1997
Essential amino acid (EAA) utilization by gastrointestinal tract (GIT) tissues has been investigated in sheep given 800 and 1,200 g/day lucerne pellets. Animals prepared with indwelling catheters into the aorta and the portal drained viscera plus cannulas into the small intestine were infused with mixed U-13C-labeled amino acid or (1-13C]leucine ...
Crandall K A - - 1997
This study examines the diverse maximum wavelength absorption (lambdamax) found in crayfishes (Decapoda: Cambaridae and Parastacidae) and the associated genetic variation in their opsin locus. We measured the wavelength absorption in the photoreceptors of six species that inhabit environments of different light intensities (i.e., burrows, streams, standing waters, and subterranean ...
Johansson E - - 1997
BACKGROUND: Antisecretory factor (AF) is a recently identified regulatory protein which inhibits the intestinal fluid secretion induced by cholera toxin. AIMS: To test the effect of AF on: (a) inflammation and hypersecretion induced by toxin A from Clostridium difficile; and (b) morphological changes and hypersecretion induced by okadaic acid (the ...
Ramirez I - - 1997
To determine whether damage to the intestinal mucosa by oleic acid causes the suppression of food intake observed in response to intraintestinal infusion of the fatty acid, we measured lactate dehydrogenase (LDH) activity, a marker for cell damage, in the intestinal lumen after intestinal infusion of fatty acid under conditions ...
Kimura T - - 1997
The GI absorption of recombinant human insulin-like growth factor-I (rhIGF-I) and its improvement were investigated in rats. The 125I-rhIGF-I rapidly degraded to the trichloroacetic acid-soluble form in the small-intestinal contents, but it was relatively stable in the gastric and large-intestinal contents and in the subcellular fraction of the small-intestinal mucosa. ...
Bowe C L - - 1997
Hydrophilic drugs are often poorly absorbed when administered orally. There has been considerable interest in the possibility of using absorption enhancers to promote absorption of polar molecules across membrane surfaces. The bile acids are one of the most widely investigated classes of absorption enhancers, but there is disagreement about what ...
Rabbaa L - - 1997
Ofloxacin, a chiral fluoroquinolone, possesses two optical isomers. The antibacterial activity of S-(-)-ofloxacin is 8 to 128 times higher than that of R-(+)-ofloxacin. In the rat, a saturable absorption process has been described for racemic ofloxacin. In the present study we investigated the mechanism underlying the in vivo intestinal absorption ...
Yoshikawa H - - 1997
Rectal absorption of 32-mer phosphorothioate deoxynucleotides (S-Oligo) in the rat was attempted with the aid of a suppository containing oleic acid and a surfactant. Although, the suppository without adjuvant did not show detectable blood levels, that containing over 10% oleic acid enabled the absorption of S-Oligo with tmax at 2 ...
Jones R T - - 1997
The use of 14C-labelled amino acids enables the measurement of both the total substantivity to hair and the degree of penetration into the hair shaft of amino acid mixtures derived from complete hydrolysis of proteins. The technique utilizes the fact that direct measurement of 14C radioactivity of the treated hair ...
Grøndahl M L - - 1997
Most amino acids are, like glucose, co-transported with sodium and are thereby potential additives to oral rehydration solutions for the treatment of diarrhea. In this study the effects of mucosal amino acids on short-circuit current and Na and Cl fluxes in three segments of the porcine small intestine were studied. ...
Vermehren C - - 1997
The absorption enhancer, didecanoylphosphatidylcholine (DDPC), improves the nasal absorption of human growth hormone in rabbits. We elucidated the uptake and the metabolism of 1,2-di[1-14C]decanoyl-L-3-phosphatidylcholine and 1,2-didecanoyl-L-3-phosphatidyl[N-methyl-3H]choline in rabbit nasal mucosa in vivo. One minute after nasal application of DDPC, 4.4-7.5% of the applied dose was found absorbed into the mucosa. ...
Uhing M R - - 1997
BACKGROUND & AIMS: Most studies of intestinal amino acid absorption use methods in which intestinal function is studied immediately after surgical manipulation. The unphysiological experimental conditions present in these studies limit the ability to extrapolate their results to normal physiological conditions. The aim of this study was to determine the ...
Sigalet D L - - 1997
BACKGROUND: Medium-chain triglycerides are used for the treatment of malabsorptive states. We measured directly the absorption of medium- and long-chain fatty acids via the mesenteric lymphatics and portal vein in normal animals. These results may be useful in guiding therapy for short-bowel syndrome. METHODS: Under anesthesia, male Lewis rats (n ...
Thomson A B AB Department of Medicine, University of Alberta, Edmonton. - - 1997
Significant advances have been made in the study of the small bowel. Part I of this two-part review of the small bowel examines carbohydrates, including brush border membrane hydrolysis and sugar transport; amino acids, dipeptides, proteins and food allergy, with a focus on glutamine, peptides and macromolecules, and nucleosides, nucleotides ...
Rawashdeh N M - - 1997
Pharmacokinetic behavior of single dose of 2 mefenamic acid capsule formulations was studied in a randomized crossover design in 22 healthy male volunteers. Following ingestion of 250 mg of either of the products, blood samples were obtained over a 14-hour period and the serum drug concentrations were determined by an ...
Owen T J - - 1997
Glutaraldehyde treatment of collagen biomaterials promotes calcification, poor host-tissue incorporation, and ultimately mechanical failure of bioprotheses. Porcine small-intestinal submucosa (SIS) is a biomaterial which has been investigated for several applications including arterial and venous grafts and repair of tendon, ligament, body wall, and urinary bladder defects. The calcification potential of ...
Saitoh H - - 1997
PURPOSE: The purpose of this study was to test whether structural modifications improve the intestinal absorption of DMP 728 (cyclo(D-Abu-NMeArg-Gly-Asp-Amb)), a GPIIb/IIIa receptor antagonist. METHODS: In vitro permeabilities of prodrugs and analogs of DMP 728 across excised rat intestinal segments were determined. RESULTS: n-Butyl and n-octyl esters of DMP 728 ...
Unno N - - 1997
BACKGROUND: Nitric oxide (NO.) increases the permeability of cultured intestinal epithelial monolayers. NO. reacts with superoxide anion to form peroxynitrite anion, which can be protonated under mildly acidic conditions to form the potent and versatile oxidizing agent, peroxynitrous acid. We hypothesized that intracellular acidosis induced by the Na(+)-H+ antiport blocker, ...
Stevenson C M - - 1997
The absorption of gabapentin was investigated by monitoring drug plasma levels as a function of time following midjejunal administration in mongrel dogs. From previous work, dose-dependent absorption had been postulated to be a consequence of carrier-mediated transport and a paracellular pathway had been postulated to contribute to the passive absorption ...
O'Mara F P - - 1997
The amino (AA) profile of eight feedstuffs (two samples of fishmeal, soybean meal [SBM], formaldehyde-treated SBM, sopralin, cotton-seed meal [CSM], rapeseed meal [RSM], corn distillers grains [CDG], and corn gluten feed [CGF]) was determined before and after ruminal incubation for 8 and 12 h in three lactating Friesian cows using ...
Sastry S S - - 1997
The photoreaction of psoralens with DNA is a well-characterized reaction. However, the photoreactions of psoralens with proteins is not very well understood. Our objective was to isolate an amino acid-psoralen photochemical adduct. We photoreacted 8-methoxypsoralen (8-MOP) with T7 RNA polymerase, a protein that carries out the fundamental biological process of ...
Zeldin D C - - 1997
Our laboratory recently described a new human cytochrome P450 arachidonic acid epoxygenase (CYP2J2) and the corresponding rat homologue (CYP2J3), both of which were expressed in extrahepatic tissues. Northern analysis of RNA prepared from the human and rat intestine demonstrated that CYP2J2 and CYP2J3 mRNAs were expressed primarily in the small ...
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