Science topic

Intestinal Absorption - Science topic

Uptake of substances through the lining of the INTESTINES.
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I found only one reference so far saying that it´s around 4% of goblet cells in the duodenum and the number is increasing towards the colon where it is around 16%. I need a reliable number for the human (!) jejunum. As always, most data is found for mice.
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Annika Jaenicke I am looking data for number of goblet cells per villus but I do not find a good one. Could you help me with that? I will be thankful!
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We are seeking to demonstrate small intestinal absorption of 3-O-methyl-D-glucose in one of our patient cohorts.
I am looking for:
1. A supplier of 3-OMG that is certified for oral administration in humans
2. A detailed protocol for measurement of 3-OMG levels in plasma/serum by high performance liquid chromatography (or any other methods!)
Any advice would be greatly appreciated!
Thanks, 
Jessie
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Great, thank you. I will bear that in mind. 
It looks like this product is no longer widely available in a form that is certified for use in humans, unfortunately. There is one potential supplier who I am waiting to hear from. I will post here if have any success. 
J
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Dear researchers,
I like to follow the microscopic mass balance approach for predicting intestinal absorption. Three dimensionless numbers viz., dose number, absorption number, and dissolution number can be calculated with the appropriate parameters. Then these dimensionless numbers can be substituted in the differential equations and it can be solved together.
I found an article published in Springer, AAPS PharmSciTech (attached).
I followed the same values and try to solve with R program, I can't able to solve (Authors used Matlab to solve the differential equations). Please give an idea to solve these differential equations.
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Dear Joseph
May be you can try using a function that smoothens the particle size dissolution rate ( variable y1 in your code). In general smoothing functions will perform better than any if else type formalism. 
I also tried methods = "rk4". However, the results dont match. Seems this needs stiff solvers. Let me know if this makes sense to you.
Raja
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I have performed release experiment of poorly water-soluble drug from different polymer matrix. I have used simulated intestinal fluid SIF conform to USP (pH 7.4 buffer solution). As suspected the release has been close to zero. On the other side, the in-vivo experiment demonstrate the intestinal absorption of the drug. Do exist  simulated intestinal fluid appropriate for poorly water-soluble drugs?
Best regards
Marco   
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Dear Marco,
from my experience I would recommend not only the change of composition of the fluid but also the method choice. In case of poorly soluble drugs, dissolution in apparatus 4 give positive effects. It give you possibility of use closed or open loop disolution. 
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I wants to measure mRNA expression in biopsies from human jejunum/ileum, and my end point after treatment is absorption. I am planning to measure expression of SGLT, FABP2, calbindin, and Tight junctions proteins, but maybe you have better ideas?
Thanks
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The patients (short bowel patients) are treated with an agent and biopsies are taken before and after treatment. The patients are also going through balance studies (measuring intake/output for four days), which will give us the answer if the absorption is increased. But it would be great if we could measure some changes in mRNA markers of absorption after treatment. We hope that the agent would change the expression of e.g. tight junctions (as i does in animal experiments). So we are just looking for some good markers for absorption, that could be changed after treatment.
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I'm looking for a significative dosage to evaluate intestinal permeability in chronic disease but not in inflammatory bowel diseases 
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Dear Morgane, 
here is a review of :
Current methodologies used for evaluation of intestinal permeability and absorption
Praveen V Balimane, Saeho Chong, Richard A Morrison
Journal of Pharmacological and Toxicological Methods
Volume 44, Issue 1, July–August 2000, Pages 301–312
Current Directions in Drug Discovery:A Review of Modern Techniques
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I am looking for a method to induce intestinal permeability without inducing strong inflammation. In clear, I am looking to a smooth way to increase intestinal permeability. Any suggestions?
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increased intestinal permeability will induce bacteremia anyway at normal conditions..
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If possible please include the references.
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Hi
following link will help you:
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Could anyone suggest a detailed procedure to measure the permeability of synthesized drugs using everted intestine technique?
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Look up the work of Stanley A Kaplan who did these studies at Hoffmann-La Roce where we worked together in the 1970s
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What is the best way for removing mucus layer during the preparation of intestinal samples and after mounting it in the Ussing chamber? Usually I wash samples several times with KRB but at the middle of experiments and even after mounting of tissues in chambers I see the mucus layer at the apical surface. 
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Thanks everyone for the answer!
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I am looking for research on nutritional absorption in the GI tract and how this may interact with chronic illnesses such as IBD or autoimmune disorders. Specifically if there are any engineering models of nutritional absorption or any data sets that could use some engineering analysis. 
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See this paper:
Gretchen J. Mahler, Mandy B. Esch, Elad Tako, Teresa L. Southard, Shivaun D. Archer, Raymond P. Glahn and Michael L. Shuler. Oral exposure to polystyrene nanoparticles affects iron absorption. Nature Nanotechnology (2012). 12;7(4):264-71. doi:10.1038/nnano.2012.3.
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I am testing the intestinal permeability of some compounds using Caco-2 monolayers on Costar 3460 Transwell Permeable Supports. I have been told that you might re-use the supports, taking the cells out and starting again. Has anyone done this before? Does trypsin damages the support? How many times can you re-use the support?
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It is not advisable to re-use it. I tried it once, but the cells did not adhere completely on the membrane, and there were some gaps, especially at the boundaries of the wells. It may work for you, but if you want to save time, take a new one.
If you just want to exercise/practice and set your hand for the manipulation, then you can re-use it. But if it is a serious manipulation, dont take risk, use a new insert.
All the best Laura
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I came across articles reporting that chitosan will be released in large intestine (also it inhibits the fat digestion). But researchers produced the O/W emulsion (fish oil, beta carotene) with chitosan as stabilizer.
Will the material (betacarotene) be released in the small intestinal stage for absorption?
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Hi Joseph
Chitosan is a charged Polyaminosaccharid, it has physical properties much different than beta-Carotene, so there is not much risk that you block you absorbtion with it, Carotene has no Acid-Group and no charging that would inable an absorption on the Chitosan surface. The way of reducing fats in case of chitosan is the absorbing of free fatty acids after digestion with Lipases. The carotene itself has more affinity to lipidic environments like the fish oil, so if you can release it from there, Chitosan should not be a problem....
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We are conducting a research on metabolic effects of lignin isolated from paper production waste. Lignin is a huge net-polyphenol molecule. We can see some promissing results, but we still missing some crucial information, which is whether is lignin absorbed in the intestines and whether it is somehow metabolized before/ during absorption. Do you have some experience or ideas about labeling isolated polyphenol molecule to be able to later determine its penetration to the blood stream and organs? We were thinking about adding FITC-label. But will it endure gastric digestion and stay attached to the lignin molecule?
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Dr. Lu - these are very much the thoughts we aterted to fllow in last few days. There is a strong possibility that the lignin mixture will be very heterogenous in the molecular size, so we could have a look for smaller phenolic frangments. 
I am curious about microbiotic fermentation processes - how would you quantify such process? Would you make it in vivo, or would you make some kind of in vitro culture from animal samples? 
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The anti-inflammatory additives can alter the intestinal permeability in the pigs. The available methods measure the presence in urine of the corresponding marker. Nevertheless, the urine collection is not possible / is not easy in farm.
There exists some method that quantifies the marker in blood?
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yes you can use that as well.
What you need to remember is the half life in the blood..cause if your blood sampling events are far spaced, you want something that you can still find in the blood sample.
Good luck.
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Nanoparticle delivery systems are designed for enhancing the bioavailability of encapsulated molecules in oral administration. However, multiple factors affect the destination of nanoparticles in the gastrointestinal tract before these magic particles show their benefits for targeted compounds.
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To get this discussion started, I would like to give some opinions. 1. Different pH conditions in the gastrointestinal tract. Organic nanoparticles, such as protein based nanoparticles, may show different characteristics in the GI tract. The particle aggregation would happen in the pH near the isoelectric point of selected protein. 2. Ionic effect. ion in the GI tract may cause the agglomeration of the nanoparticles. 3. Enzymes. organic nanoparticles can be rapidly digested by enzymes. 4. Mucus. Mucus can cleanse the nanoparticles in the intestinal tract and prevent the penetration of nanoparticles to intestinal epithelial cells.
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I want to analyze the integrity of my Caco-2 monolayers by use of a fluorescent dye. Lucifer Yellow is well described in the literature for this purpose but I need another dye with a different emission/excitation spectrum!
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I found this company (http://www.bmglabtech.com/application-notes/fluorescence-intensity/tight-junctions-146.cfm) that use two different sizes of Dextran: (4kDa-FITC and 70kDa-Rhodamine B). A bit more research on Rhodamine B suggest that it is classified as hydrophilic dye. My guess is if you can give a try to Rhodamine B. Otherwise you may also give a try to the propidium iodine, not the best but commonly used to sort live and dead cells (I believe there is some efflux in living cells).