Passage of iron out of the intestinal mucosa of the rat

1980 ◽  
Vol 58 (2) ◽  
pp. 129-133 ◽  
Author(s):  
A. B. R. Thomson ◽  
L. S. Valberg
Keyword(s):  
Intestinal Mucosa ◽  
Concentration Gradient ◽  
Test Dose ◽  
The Body ◽  
Intestinal Lumen ◽  
Iron Transfer ◽  
Iron Stores ◽  
Kinetics Of ◽  
Initial Uptake

To determine the effect of removal of the "lumen-to-mucosa" concentration gradient on the passage of iron (Fe) out of the intestine, duodenal loops of rats with loaded (FeL) or deficient (FeD) iron stores were perfused for 30 min with 5.0 mM solutions containing 59Fe. The test solutions were then removed and in vivo perfusion of the washed mucosa was continued for up to 60 min with saline or unlabelled Fe–saline. Despite the greater initial uptake of Fe by FeD than FeL, continued perfusion with saline was associated with the appearance of similar quantities of 59Fe in the perfusate; in contrast, when perfusion was continued with Fe-saline, the loss of 59Fe into the perfusate was increased and was twice as great in FeD as in FeL. Iron transfer to the carcass was higher in FeD than in FeL, but continued perfusion with saline was associated with the appearance of increased amounts of 59Fe in the carcass of FeL but not FeD; the amount of 59Fe appearing in the carcass was greatly increased in both FeD and FeL by continued perfusion with Fe–saline. Thus, the amount of 59Fe available for entry into the intestinal lumen and carcass after removal of the lumen-to-mucosa concentration gradient is influenced by the size of the body iron stores and by the presence of iron in the fluid remaining in the lumen. Therefore, the amount of iron in the fluid remaining in the intestinal lumen after the administration of the Fe test dose must be carefully defined when estimating the kinetics of the intestinal absorption of iron.

scholarly journals Amniotic fluid fibronectin. Characterization and synthesis by cells in culture.

1978 ◽  
Vol 78 (3) ◽  
pp. 701-715 ◽  
Author(s):  
E Crouch ◽  
G Balian ◽  
K Holbrook ◽  
D Duksin ◽  
P Bornstein
Keyword(s):  
Amniotic Fluid ◽  
Matrix Protein ◽  
Sodium Dodecyl ◽  
Basement Membranes ◽  
The Body ◽  
Connective Tissues ◽  
Human Amniotic Fluid ◽  
Cold Insoluble Globulin ◽  
Kinetics Of

A glycoprotein immunologically related to plasma cold-insoluble globulin (CIG) and fetal skin fibroblast fibronectin has been purified from second-trimester human amniotic fluid. This protein (amniotic fluid fibronectin) migrated more slowly than CIG on sodium dodecyl sulfate gel electrophoresis and showed greater polydispersity which could result, at least in part, from heterogeneity in glycosylation. Cloned human amniotic fluid epithelioid and fibroblastic cells synthesized and secreted a protein with similar properties into the culture medium. Fibronectin was shown to be associated with the pericellular and extracellular matrix of cultured amniotic fluid cells by immunofluorescence, lactoperoxidase-catalyzed iodination, and labeling with ferritin-conjugated antibodies. The kinetics of secretion of the protein were consistent with its role as a matrix protein. We anticipate that amniotic fluid fibronectin will prove to be the same protein which elsewhere in the body is incorporated into connective tissues and basement membranes. Amniotic fluid could, therefore, serve as a convenient source of in vivo synthesized fibronectin for biological and structural studies.

scholarly journals In vivo Determination of Amino Acid Bioavailability in Humans and Model Animals

2005 ◽  
Vol 88 (3) ◽  
pp. 923-934 ◽  
Author(s):  
Malcolm F Fuller ◽  
Daniel Tomé
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
The Body ◽  
Whole Body ◽  
Intestinal Lumen ◽  
Stable Isotope Labelling ◽  
Ileal Digestibility ◽  
Hydrolyzed Protein ◽  
Protein Free Diet

Abstract Because the digestion of many dietary proteins is incomplete, and because there is a continuous (but variable) entry into the intestinal lumen of endogenous protein and amino acid nitrogen that is also subject to digestion, the fluxes of nitrogen, amino acids, and protein in the gut exhibit a rather complicated pattern. Methods to distinguish and quantitate the endogenous and dietary components of nitrogen and amino acids in ileal chyme or feces include the use of a protein-free diet, the enzyme-hydrolyzed protein method, different levels of protein intake, multiple regression methods, and stable-isotope labelling of endogenous or exogenous amino acids. Assessment of bioavailability can be made, with varying degrees of difficulty, in man directly but, for routine evaluation of foods, the use of model animals is attractive for several reasons, the main ones being cost and time. Various animals and birds have been proposed as models for man but, in determining their suitability as a model, their physiological, enzymological, and microbiological differences must be considered. Fecal or ileal digestibility measurements, as well as apparent and true nitrogen and amino acid digestibility measurements, have very different nutritional significance and can, thus, be used for different objectives. Measurements at the ileal level are critical for determining amino acid losses of both dietary and endogenous origin, whereas measurements at the fecal level are critical in assessing whole-body nitrogen losses. A complementary and still unresolved aspect is to take into account the recycling of intestinal nitrogen and bacterial amino acids to the body.

STUDYING THE ROLE OF MACROPHAGES IN CIRCULATING PROSTATE CANCER CELLS BY IN VIVO FLOW CYTOMETRY

2012 ◽  
Vol 05 (04) ◽  
pp. 1250027 ◽  
Author(s):  
JIN GUO ◽  
ZHICHAO FAN ◽  
ZHENGQIN GU ◽  
XUNBIN WEI
Keyword(s):  
Prostate Cancer ◽  
Flow Cytometry ◽  
Cancer Cells ◽  
The Body ◽  
Prostate Cancer Cells ◽  
In Vivo Flow Cytometry ◽  
Kinetics Of ◽  
Deficient Group

Metastasis is a very complicated multi-step process and accounts for the low survival rate of the cancerous patients. To metastasize, the malignant cells must detach from the primary tumor and migrate to secondary sites in the body through either blood or lymph circulation. Macrophages appear to be directly involved in tumor progression and metastasis. However, the role of macrophages in affecting cancer metastasis has not been fully elucidated. Here, we have utilized an emerging technique, namely in vivo flow cytometry (IVFC) to study the depletion kinetics of circulating prostate cancer cells in mice and determine how depletion of macrophages by the liposome-encapsulated clodronate affects the depletion kinetics. Our results show different depletion kinetics of PC-3 cells between the macrophage-deficient group and the control group. The number of circulating tumor cells (CTCs) in the macrophage-deficient group decreases in a slower manner compared to the control mice group. The differences in depletion kinetics indicate that the absence of macrophages facilitates the stay of prostate cancer cells in circulation. In addition, our imaging data suggest that macrophages might be able to arrest, phagocytose and digest PC-3 cells. Therefore, phagocytosis may mainly contribute to the depletion kinetic differences. The developed methods elaborated here would be useful to study the relationship between macrophages and tumor metastasis in small animal cancer models.

Effect of Surface Charge on Gold Nanoparticle Biotransport: An In Vivo Blood and Biodistribution Study

2011 ◽  
Author(s):  
Neha B. Shah ◽  
John C. Bischof
Keyword(s):  
Surface Properties ◽  
Metallic Nanoparticles ◽  
Serum Proteins ◽  
Critical Issue ◽  
The Body ◽  
Great Promise ◽  
Phagocytic Cells ◽  
Kinetics Of

Intravenously injected nanoparticles (NPs) hold great promise for clinical diagnostic and therapeutic applications. While several NPs for such clinical applications have emerged in various designs (metallic, polymeric, quantum dots etc.) [1], a critical issue in their in vivo use is the lack of fundamental studies examining the effects of physicochemical parameters (shape, size, surface properties etc.) on blood circulation, kinetics of accumulation and elimination as well as toxicity [2–4]. We hypothesize that blood, the first medium of interaction in the body, is a major determinant of biotransport and biodistribution. Recent and past in vitro studies have shown that NPs interact with serum proteins (including complement factors), cause platelet aggregation and red blood cell hemolysis, and are taken up by phagocytic cells. However, to our knowledge a detailed in vivo study of the interaction of metallic nanoparticles with blood components as a function of their surface properties does not yet exist.

Innovation of hyaluronic acid-protamine microparticles and their kinetics in vivo

2016 ◽  
Vol 26 (01n02) ◽  
pp. 45-51 ◽  
Author(s):  
S. Harada ◽  
S. Ehara ◽  
T. Segawa ◽  
K. Ishii ◽  
T. Sato ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Anticancer Drug ◽  
The Body ◽  
The Mean ◽  
Kinetics Of ◽  
Pixe Method ◽  
Kinetics In Vivo ◽  
Number Of Particles

The nanoparticles, which releases anticancer drug with response to radiation, were developed. Also, two categories were tested: (i) their ability to release anticancer drug in vitro; and (ii) their kinetics in the body, when they were injected through tail vein of BALB/c mice in vivo. To prepare the particles, hyaluronic acid and protamine were mixed into carboplatin solution, and reacted for 30 min in room temperature. Those particles were exposed to a single dose of 10 Gy of 140 KeV X-ray. Their ability to release carboplatin with response to radiation was expressed as the percentage of ruptured particles, basing on images of particles, using micro PIXE camera. The amount of released carboplatin was measured by quantitative PIXE method. The kinetics of particles in body was assessed by counting the number of particles, which were trapped in lungs, using micro PIXE camera. The mean diameter of particles was 743 ± 34 nm. By irradiation, 59.3 ± 7.23% of particles ruptured, and 95.9 ± 2.3% carboplatin was released from particles. The trapped particles in lungs were significantly reduced, when compared with previous alginate-hyaluronic particles.

Microscopic evidence for the uptake of orally given humic acids by the intestinal mucosa in piglets

2011 ◽  
Vol 51 (10) ◽  
pp. 967
Author(s):  
K. Buesing ◽  
J. Harmeyer ◽  
K. D. Markuske ◽  
A. Zeyner
Keyword(s):  
Humic Acid ◽  
Humic Acids ◽  
Intestinal Mucosa ◽  
Tissue Sample ◽  
Intestinal Barrier ◽  
The Body ◽  
Intestinal Lumen ◽  
Therapeutic Effects ◽  
Tissue Samples ◽  
Body Tissues

In veterinary medicine, humic acids are sometimes used as oral supplements to protect and treat young animals from diarrhoea. With regard to their mode of action, it was generally believed that humic acids are unable to penetrate the intestinal mucosal surface and rather act from the intestinal lumen. In the past, some reports indicated, however, that prophylactic and therapeutic effects of orally administered humic acids might not be confined to the lumen of the digestive tract. The present study used piglets to examine whether orally administered humic acids would be able to cross the intestinal barrier and if so, whether the humic acids would also be transported from the intestine to other regions of the body. The study was carried out with three 64-day-old piglets, two of which were bottle fed daily with 1 g humic acids/kg bodyweight and day for 2 weeks. The third piglet served as an unsupplemented control. At the end of the study, the piglets were slaughtered and 10 tissue specimens were collected from each piglet. Examination by light microscopy of unstained sections revealed the presence of humic acid particles in each tissue sample from both humic acid-treated piglets whereby no such deposits were found in any tissue of the control piglet. This demonstrated that the humic acids had indeed passed the epithelial barrier of the intestinal mucosa and had been transported to other body tissues. In most tissue samples the humic acid particles showed a distinct clustered distribution pattern.

scholarly journals Corrosion of Metallic Biomaterials: A Review

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 407 ◽  
Author(s):  
Noam Eliaz
Keyword(s):  
The Body ◽  
Cobalt Chromium ◽  
Corrosion Resistant ◽  
Metallic Biomaterials ◽  
Chromium Alloys ◽  
Biodegradable Metals ◽  
Dental Amalgams ◽  
Kinetics Of ◽  
Factor Governing

Metallic biomaterials are used in medical devices in humans more than any other family of materials. The corrosion resistance of an implant material affects its functionality and durability and is a prime factor governing biocompatibility. The fundamental paradigm of metallic biomaterials, except biodegradable metals, has been “the more corrosion resistant, the more biocompatible.” The body environment is harsh and raises several challenges with respect to corrosion control. In this invited review paper, the body environment is analysed in detail and the possible effects of the corrosion of different biomaterials on biocompatibility are discussed. Then, the kinetics of corrosion, passivity, its breakdown and regeneration in vivo are conferred. Next, the mostly used metallic biomaterials and their corrosion performance are reviewed. These biomaterials include stainless steels, cobalt-chromium alloys, titanium and its alloys, Nitinol shape memory alloy, dental amalgams, gold, metallic glasses and biodegradable metals. Then, the principles of implant failure, retrieval and failure analysis are highlighted, followed by description of the most common corrosion processes in vivo. Finally, approaches to control the corrosion of metallic biomaterials are highlighted.

Kinetic profile of overall elimination of 5-methyltetrahydropteroylglutamate in rats

1999 ◽  
Vol 276 (3) ◽  
pp. E580-E587 ◽  
Author(s):  
Yong-Hae Han ◽  
Yukio Kato ◽  
Hiroyuki Kusuhara ◽  
Hiroshi Suzuki ◽  
Minoru Shimoda ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
The Body ◽  
Parallel Increase ◽  
Liver Concentration ◽  
Renal Tubular Reabsorption ◽  
Total Body ◽  
Renal Tubular ◽  
Kinetics Of ◽  
Body Clearance

The in vivo biliary and urinary excretion kinetics of 5-methyltetrahydropteroylglutamate (5-CH3-H4PteGlu) were studied in rats. During infusion at various rates (48–965 nmol ⋅ h−1⋅ kg−1), the total body clearance (CLtotal) of 5-CH3-H4PteGlu could be attributed almost entirely to the sum of the biliary and urinary (CLurine,p) excretion clearances. After a 4-h infusion at the highest rate, the 5-CH3-H4PteGlu in the liver was 10 times higher than the endogenous level, whereas its polyglutamate form did not increase, suggesting that most of the infused 5-CH3-H4PteGlu is not incorporated in the polyglutamate pool but is eliminated by excretion. The parallel increase in CLtotaland CLurine,pwith the increase in infusion rate might result from saturation of reabsorption at the renal proximal tubules, since the urinary excretion clearance, defined with respect to the kidney concentration, also increased while the biliary excretion clearance, defined with respect to the liver concentration, remained almost constant. We conclude that the hepatobiliary excretion is a relatively low-affinity process with a constant clearance, whereas the renal tubular reabsorption is saturated at higher plasma 5-CH3-H4PteGlu concentration (∼0.5 μM). Urinary excretion becomes the predominant elimination route for any excess 5-CH3-H4PteGlu in the body.

Activation of isolated heterophils from chicks stimulated in vivo with salmonella enteritidis-immune lymphokines

1996 ◽  
Vol 54 ◽  
pp. 760-761
Author(s):  
R. B. Moyes ◽  
R. E. Droleskey ◽  
M. H. Kogut ◽  
J. R. DeLoach
Keyword(s):  
Lamina Propria ◽  
Intestinal Mucosa ◽  
Salmonella Enteritidis ◽  
Intestinal Tract ◽  
Polymorphonuclear Cells ◽  
Subclinical Infection ◽  
Egg Products ◽  
Immune Lymphokines ◽  
Organ Invasion

Salmonella enteritidis (SE) is of great concern to the poultry industry due to the organism's ability to penetrate the intestinal mucosa of the laying hen and subsequently colonize the ovaries and yolk membrane. The resultant subclinical infection can lead to SE infection of raw eggs and egg products. Interference with the ability of the organism to invade has been linked to the activation and recruitment of inflammatory polymorphonuclear cells, heterophils, to the lamina propria of the intestinal tract.Recently it has been established that heterophil activation and increased resistance to SE organ invasion can be accomplished by the administration of SE-immune lymphokines (SE-ILK) obtained from supernatants of concanavalin-A stimulated SE immune T lymphocytes from SE hyperimmunized hens. Invasion of SE into the lamina propria provides a secondary signal for directing activated heterophils to the site of SE invasion.

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

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