scholarly journals Digestion-on-a-chip: a continuous-flow modular microsystem recreating enzymatic digestion in the gastrointestinal tract

Lab on a Chip ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 1599-1609 ◽  
Author(s):  
Pim de Haan ◽  
Margaryta A. Ianovska ◽  
Klaus Mathwig ◽  
Glenn A. A. van Lieshout ◽  
Vassilis Triantis ◽  
...  

A three-compartment, miniaturized system to pretreat samples with artificial saliva, gastric juice, duodenal juice and bile for gut-on-a-chip applications.

1975 ◽  
Vol 34 (02) ◽  
pp. 409-418 ◽  
Author(s):  
I. M Nilsson ◽  
S.-E Bergentz ◽  
U Hedner ◽  
K Kullenberg

SummaryGastric juice from 15 normals, 20 patients with gastric ulcer and 4 patients with erosive haemorrhagic gastroduodenitis was investigated in respect of its activity on unheated and heated fibrin plates and its content of FDP and plasminogen or plasmin with immunochemical methods. Gastric juice from normals showed no activity on unheated and heated fibrin plates, and no FDP or plasminogen could be demonstrated. In the patients with gastric ulcer the gastric juice showed little or no fibrinolytic activity on fibrin plates except in 2, who had regurgitation of duodenal juice and neutral pH of the juice. These patients had equally high activity on heated as on unheated plates and no plasmin could be demonstrated. It was shown that this activity was not due to fibrinolysis, but to non-specific proteolytic activity (probably trypsin). The patients with erosive haemorrhagic gastroduodenitis exhibited quite a different picture. The gastric juice from these patients showed extremely high activity on fibrin plates, the activity was higher on unheated than on heated plates. The activity was inhibited in vitro by addition of EACA and in vivo after administration of AMCA. The occurrence of plasmin could be demonstrated directly immunologically in the gastric juice. By comparison of plasmin and trypsin in various assays it could further be proved that the gastric juice in these cases contained plasminogen activator and plasmin. The patients with erosive haemorrhagic gastroduodenitis showed no increase in fibrinolysis in the blood, but low values for plasminogen and α2M, and the serum contained FDP. These findings in the blood and gastric juice were interpreted as signs of local fibrinolysis in the stomach and duodenum. There is reason to assume that this gastric fibrinolysis contributes substantially to the bleeding tendency. The effect of administration of AMCA on fibrinolytic activity and the haemorrhage lends support to the assumption of such a mechanism.


2009 ◽  
Vol 72 (5) ◽  
pp. 959-965 ◽  
Author(s):  
CYNTHIA L. SHEFFIELD ◽  
TAWNI L. CRIPPEN ◽  
KATHLEEN ANDREWS ◽  
ROY J. BONGAERTS ◽  
DAVID J. NISBET

Recent concerns about the use of antimicrobials in food animals have increased interest in the microbial ecology and biofilms within their gastrointestinal tract. This work used a continuous-flow chemostat system to model the microbial community within the ceca from day-of-hatch chicks and its ability to resist colonization by Salmonella enterica serovar Typhimurium. We characterized the biofilm and planktonic communities from five cultures by using automated ribotyping. Eight species from six different genera were identified. Overall, the planktonic communities were more diverse, with 40% of the cultures containing four or more bacterial species. Eighty percent of the biofilm communities contained only one or two species of bacteria. Enterococcus faecalis was the only species isolated from all communities. None of the resulting microbial communities was able to resist colonization by S. enterica serovar Typhimurium. This is the first study to provide a molecular-based characterization of the biofilm and planktonic communities found in day-of-hatch chicken cecal microflora cultures.


1978 ◽  
Vol 173 (3) ◽  
pp. 705-712 ◽  
Author(s):  
George Marcoullis ◽  
Hannele Merivuori ◽  
Ralph Gräsbeck

The vitamin B12 binders in the pig pyloric mucosa gastric and intestinal juice from the upper gastrointestinal tract were fractionated into only two molecular forms, classified as intrinsic factor and cobalophilin. The unsaturated vitamin B12-binding power due to cobalophilin was lower in the intestinal than in the gastric juice. Electrofocusing revealed that intrinsic factor and cobalophilin in the intestinal juice contained more of the ‘neutral’-type isoproteins, and the suggestion is made that this is due to enzyme activity. The gastric-juice intrinsic factor contained more acidic isoproteins, which supports the hypothesis that carbohydrate is added on to the polypeptide chain of this protein before it is secreted into gastric juice. The gastric- and intestinal-juice cobalophilins, studied also by electrofocusing, differed from that of pyloric mucosa and they appeared to be of salivary origin. With regard to molecular dimensions there was no significant difference between the intrinsic factors and cobalophilins from all sources studied. All cobalophilins had molecular weights by the formula of Svedberg of approx. 92500, Stokes radii of 4.62nm and sedimentation coefficients of 5.15S. The corresponding values for the intrinsic factors were 63600, 3.57nm and 4.38S. In addition, the intrinsic factors exhibited similar avidities for binding to the solubilized ileal intrinsic-factor receptor. Also the intrinsic factors and cobalophilins, irrespective of their source, bound to the analogous specific xenoantibodies with the same avidity. The present results demonstrate that intrinsic factor remains practically unaltered during its passage through the proximal intestine and render unlikely the speculations made about the presence of an endogenous binder for intrinsic factor as well as the existence of a ‘pancreatic intrinsic factor’. In addition, they are compatible with the theory that the interference by undegraded cobalophilin may be the reason for the abnormal vitamin B12 absorption observed in patients with pancreatic insufficiency.


1998 ◽  
Vol 94 (3) ◽  
pp. 313-319 ◽  
Author(s):  
L. A. James ◽  
P. G. Lunn ◽  
S. Middleton ◽  
M. Elia

1. The activities of the two key enzymes involved in glutamine metabolism, glutaminase and glutamine synthetase, were measured in mucosal biopsies taken from different sites throughout the human gastrointestinal tract, from oesophagus to rectum. 2. The specific activity of glutamine synthetase was highest in the stomach (4.5 nmol glutamine formed per minute per mg of protein), but both small and large intestine and the oesophagus had little synthesizing capacity (less than 0.3 nmol of glutamine formed per minute per mg of protein). 3. Glutaminase specific activity was highest in the small intestine (53 nmol glutamate formed per minute per mg of protein by duodenal mucosa), intermediate in the large intestine and lowest in the oesophagus and stomach (less than 13 nmol of glutamate formed per minute per mg of protein). 4. The glutamine concentration in the mucosa was lower in the duodenum than in the colon (0.62 and 0.95 mmol/kg wet weight respectively), but both were much lower than the measured Km values of glutaminases obtained from these sites (3.8 and 4.0 mmol/kg wet weight respectively). 5. The concentration of glutamine in saliva, stomach juice, bile and duodenal juice suggests that very little glutamine passes into the gastrointestinal tract via these secretions. 6. The study provides the most complete information on the distribution of glutamine synthetase and glutaminase along the human gastrointestinal tract, and suggests that (i) both the small and large intestines have a high potential for glutamine metabolism, but little synthesizing capacity, thus both must derive their glutamine from other sources, and (ii) neither the stomach nor the oesophagus have a high glutaminase activity, although the stomach has substantial capacity to synthesize glutamine. The distribution of the enzymes along the gastrointestinal tract may help rationalize the use of glutamine for treating diseases that affect different parts of the gastrointestinal tract.


1937 ◽  
Vol 33 (9) ◽  
pp. 1058-1064
Author(s):  
E. S. Kharizomenova

In 1933, the Nikolaev kumis-treatment sanatorium was admitted along with patients with stomach disease and closed form of pulmonary tuberculosis (open forms of tuberculosis are not accepted at all), as well as patients with diseases of the gastrointestinal tract, accompanied by both low and high acidity of gastric juice.


2008 ◽  
Vol 74 (15) ◽  
pp. 4711-4718 ◽  
Author(s):  
Sarah Lebeer ◽  
Ingmar J. J. Claes ◽  
Tine L. A. Verhoeven ◽  
Chong Shen ◽  
Ivo Lambrichts ◽  
...  

ABSTRACT It is generally believed that probiotic bacteria need to survive gastrointestinal transit to exert a health-promoting effect. In this study, a genuine luxS mutant and a luxS mutant containing unknown suppressor mutations of the probiotic strain Lactobacillus rhamnosus GG were compared to the wild type for survival and persistence in the murine gastrointestinal tract. The LuxS enzyme, catalyzing the production of the autoinducer-2 signaling molecule, also forms an integral part of the activated methyl cycle and the metabolism of methionine and cysteine. The genuine luxS mutant CMPG5412 showed drastically reduced persistence in mice, which was related to less survival in simulated gastric juice, indicating that LuxS metabolism is crucial for the gastric stress resistance of L. rhamnosus GG. The suppressor mutations in the other luxS mutant, CMPG5413, appear to compensate for the metabolic defects of the luxS mutation and to restore the resistance to gastric juice but cause a defect in adherence, biofilm formation, and exopolysaccharide production. The shorter residence time of this suppressor mutant in the murine gastrointestinal tract indicates a role for biofilm formation and exopolysaccharides in the persistence capacity of L. rhamnosus GG.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Sumio Chono ◽  
Megumi Matsui ◽  
Katsuki Nakamura ◽  
Ryoya Kasai

Objectives. We evaluated the ingestibility and formulation quality of one branded (formulation A) and five generic (formulations B, C, D, E, and F) lansoprazole orally disintegrating (OD) tablets. Methods. Ingestibility, including the oral disintegrating time, taste, mouth feeling, and palatability, was examined by sensory testing in healthy subjects. Formulation qualities, including salivary stability, gastric acid resistance, and intestinal dissolution behavior, were examined. Results and Discussion. The oral disintegration time of formulation F (52 s) was significantly longer than that of other formulations (32–37 s). More than 90% of subjects did not experience bitterness with formulations A, E, and F, whereas 50% of subjects felt rough and powdery sensations with formulations B, C, and D. More than 80% of subjects suggested that formulations A, E, and F had good palatability. Ingestibility was different between formulations. OD tablets consist of enteric granules containing lansoprazole, which is unstable in gastric acid. Enteric granules of each formulation were stable in artificial saliva and gastric juice. No differences were observed in dissolution behaviors among the formulations, indicating that the formulation quality of the formulations was almost equivalent. Conclusions. This study provides useful information for selecting branded or generic lansoprazole OD tablets for individualized treatments.


1923 ◽  
Vol 19 (6) ◽  
pp. 98-98
Author(s):  
V. Bogolyubov

Of the peculiarities of gastric digestion in peptic ulcer the absolute or relative increase in acidity of gastric juice is in the foreground. Gastric ulcer surgeries-gastroenterostomy (alone or with disconnection of the pylorus) and gastric resection-achieve their purpose by facilitating the discharge of duodenal juice into the stomach and a more rapid emptying of the stomach of its contents.


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