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The Airway and Vasoactive Intestinal Peptide Autoantibodies and Receptors
Published in Devendra K. Agrawal, Robert G. Townley, Inflammatory Cells and Mediators in Bronchial Asthma, 2020
VIP binding by the soluble extract was almost completely inhibited (by 97.2%) by treatment with bovine pancreatic trypsin, and the effect of trypsin was reversed by soya bean trypsin inhibitor, indicating that the receptors are proteins.39 Concanavalin-A immobilized on Sepharose® (Con A-Seph) and Jackalin immobilized on agarose (Jack-Ag) retained 93% and 30% of the binding activity of the solubilized extract, respectively. α-D-Methyl-mannoside and α-D-melibiose eluted 9% and 15% of the retained activity from Con-Seph and Jack-Ag columns, respectively. The retention of a large proportion of the binding activity by the lectin columns suggests that VIP receptors contain glycosidic residues.
Peripheral Mechanisms of Mammalian Sweet Taste
Published in Robert H. Cagan, Neural Mechanisms in Taste, 2020
William Jakinovich, Dorothy Sugarman
In a structure-activity study using the gerbils’s whole nerve response, Jakinovich9 found that turanose and palatinose, two disaccharides which closely resemble sucrose, are not as potent stimuli as sucrose (Figure 1, Table 2). Even though these two compounds contain the same monosaccharides as sucrose (glucose and fructose) with alpha glycosidic linkages, the linkage carbons of the fructose molecules are different, thus allowing the fructose moiety to mutarotate. Among the glucopyranosides tested, those with the alpha linkage, such as maltose and maltitol, are more potent stimuli than those with the beta linkage, such as cellobiose and cellobiitol. On the other hand, galactopyranosides with the beta linkage, such as lactose and lactitol, are more potent to the gerbil than melibiose and melibiitol, which contain the alpha linkage. In human psychophysical investigations, Moskowitz21 and Lee30 reported maltose to be sweeter than cellobiose and lactose to be sweeter than melibiose, suggesting that humans and gerbils have the same structure-activity requirements for these disaccharides.
Alcohol and Small Intestinal Permeability
Published in Victor R. Preedy, Ronald R. Watson, Alcohol and the Gastrointestinal Tract, 2017
Ingvar Bjarnason, Andrew Macpherson
The principle of the differential urinary excretion of orally administered test substances has been used for noninvasive assessment and quantification of intestinal disaccharidase activities in humans.64-66 As shown in Figure 12.1, simultaneous ingestion of lactulose and melibiose gives a urine excretion (% dose) ratio of melibiose/lactulose approaching 1.0 as these oligosaccharides are handled in an identical fashion. However, if a hydrolyzable disaccharide (say lactose) is substituted for melibiose all the variables in Figure 12.1 will affect the two test substances equally except the enzymatic degradation of the hydrolyzable disaccharide. The rate of hydrolysis therefore determines the amount of intact lactose available for permeation.
Antiproliferative activity, cell-cycle arrest, apoptotic induction and LC-HRMS/MS analyses of extracts from two Linum species
Published in Pharmaceutical Biology, 2022
Ryma Mouna, Alexis Broisat, Abdalwahab Ahmed, Marlène Debiossat, Ahcène Boumendjel, Catherine Ghezzi, Zahia Kabouche
Forty flavonoids (flavones, flavonols, isoflavones, neoflavoid, chalcones, and one anthocyanidin) were detected. The major compounds were vicenin-2 isomer 1 (4), vitexin (37), trihydroxyflavone (74), homoorientin (27), vicenin-2 isomer 4 (21), vicenin-2 isomer 2 (12), vicenin-2 isomer 3 (16), cirsiliol (64), tricin 5-glucoside isomer 2 (66), 5,3′-dihydroxyflavone (17), luteolin (51), orientin isomer 1 (25), with respective percentages 8.08, 7.53, 6.70, 5.58, 5.17, 4.75, 4.67, 3.52, 3.38, 2.80, 2.61, and 2.54%. Four lignans, lanicepside B (14), olivil 4′-O-glucoside (15), a phenylnaphthalene (69), and the major compound podophyllotoxin-β-d-glucoside (71) with a percentage of 4.41%, were detected. In addition, 19 phenolic acids, from which 17 hydroxycinnamic acids and two hydroxybenzoic acids were detected with chicoric acid (24) as the major compound (8.19%). The analyses also showed the presence of one phenylethanoid (30) and one coumarin derivative (55), besides other compounds including one carbohydrate, melibiose (1), one alkaloid (26), two polyketides (50 and 75), three terpenoids (62, 68 and 76), and three fatty acids (65, 77 and 78) (Table 2).
Influence of biofilm removal from the tooth-restoration interface on the progression of secondary caries lesions: a preliminary in vitro model study
Published in Biofouling, 2020
Cácia Signori, Tamires Timm Maske, Vitor Henrique Digmayer Romero, Maximiliano Sérgio Cenci
The specimens were individually removed from the wells and carefully washed in sterile saline. The biofilm was collected from the surface (enamel/gap/resin) with sterile plastic instruments and deposited in pre-weighed microtubes. The contents of the tubes were vortexed and sonicated (Sonicador Vibra Cell - Sonics and Materials, Danbury, CT, USA) at a power of 40W and amplitude of 5% using 6 pulses of 9.9s each. Thereafter, the suspensions were diluted in saline (10−1:10−7) and inoculated in duplicate in the culture media, including blood agar for total microorganism quantification, mitis salivarius agar with 0.2 units of bacitracin ml−1 for the visual assessment of mutans streptococci, brain heart infusion agar (pH 4.8) for acid-tolerant microorganisms, and Rogosa agar for lactobacilli. The plates were incubated under an anaerobic atmosphere at 37°C for 96h. After, the numbers of colony-forming units (CFUs) were then determined by one trained operator based on colony morphology and cell morphology using a microscope and stereoscopic microscope. Representative colonies of mutans streptococci were confirmed by their capacity to ferment mannitol, sorbitol, melibiose and raffinose (Shklair and Keene 1974). Microbial counts were expressed as CFU mg−1 biofilm (wet weight).
Cellulolytic bacteria in the large intestine of mammals
Published in Gut Microbes, 2022
Alicia Froidurot, Véronique Julliand
Strains of the phylum Bacteroidota were isolated from human fecal samples.26,50,51 Robert and al. (2007)26 identified one strain as a new Bacteroides species, Bacteroides cellulosilyticus, and the type strain CRE21T is in collection (DSM 14838, CCUG 44979). The cells were Gram-negative, nonmotile, and nonsporulating rods. This newly identified cellulolytic bacterium grew on cellulose (Avicel, Sigmacell, and spinach cell wall) and exhibited poor growth on xylane. It consumed a great variety of sugars: glucose, saccharose, fructose, maltose, xylose, galactose, ribose, melibiose, mannose, lactulose, and galacturonic acid; and produced acetate, propionate, succinate, H2, lactate, and formate. Its DNA G + C content is 41.10%.