Osmotic regulation and rectal absorption in the blowfly, Calliphora erythrocephala

1969 ◽  
Vol 47 (5) ◽  
pp. 851-863 ◽  
Author(s):  
J. E. Phillips
Keyword(s):  
Rectal Wall ◽  
Blood Levels ◽  
Sugar Solution ◽  
Osmotic Gradient ◽  
Osmotic Regulation ◽  
Rectal Absorption ◽  
Calliphora Erythrocephala ◽  
Chloride Concentrations ◽  
Osmoregulatory Ability

The osmoregulatory ability of blowflies was investigated by measuring osmotic pressures and chloride concentrations of haemolymph, urine, and, under some conditions, crop and hindgut fluids from water-fed and water-deprived animals. Blood levels were kept within narrow limits by production of either very hyposmotic or strongly hyperosmotic urine. Water and chloride reabsorption from isolated recta were measured directly in vivo. While no positive evidence was obtained that ion reabsorption in the rectum plays an important role in production of hyposmotic urine, it was clearly established that hyperosmotic urine resulted from absorption of water against an increasing osmotic gradient in the latter organ. The rate of water absorption was dependent on the osmotic gradient across the rectal wall and occurred from an initially pure sugar solution as well as from saline. Current ideas on the possible mechanism of water transport in the insect rectum are discussed and assessed.

Rectal Absorption in the Desert Locust, Schistocerca Gregaria Forskål

1964 ◽  
Vol 41 (1) ◽  
pp. 15-38
Author(s):  
I. WATER ◽  
J. E. PHILLIPS
Keyword(s):  
Water Absorption ◽  
Schistocerca Gregaria ◽  
Tap Water ◽  
Rectal Wall ◽  
Ionic Concentration ◽  
Osmotic Gradient ◽  
Desert Locust ◽  
Rectal Absorption ◽  
Net Flux

1. The histology of the rectum of Schistocerca gregaria is described. 2. A method is described whereby net absorption of water from the rectum (in situ, isolated by ligation) can be measured. 3. Water is actively absorbed from the lumen of the rectum against an osmotic gradient and in the absence of a significant net flux of solute. 4. The maximum osmotic gradient developed is 2-3 times greater in locusts supplied with hypertonic saline than in locusts supplied with tap water. This indicates some ability to regulate water absorption in relation to requirement. 5. The ionic concentration of rectal fluid and the rate of salt absorption from the lumen have little effect on the maximum osmotic gradient developed across the rectal wall. 6. Possible mechanisms of active absorption of water are discussed.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

Cyclosporine increases ischemia-induced endothelial progenitor cell mobilization through manipulation of the CD26 system

2008 ◽  
Vol 294 (3) ◽  
pp. R811-R818 ◽  
Author(s):  
Chao-Hung Wang ◽  
Wen-Jin Cherng ◽  
Ning-I Yang ◽  
Chia-Ming Hsu ◽  
Chi-Hsiao Yeh ◽  
...  
Keyword(s):  
Critical Role ◽  
Serum Levels ◽  
Blood Levels ◽  
Short Term ◽  
Endothelial Progenitor ◽  
Beneficial Effects ◽  
Dpp Iv ◽  
Before And After ◽  
Cell Mobilization

Cyclosporin A (CsA) improves the success rate of transplantation. The CD26/dipeptidylpeptidase IV (DPP IV) system plays a critical role in mobilizing endothelial progenitor cells (EPCs) from bone marrow. This study investigated whether CsA manipulates CD26/DPP IV activity and increases EPC mobilization. C57BL/6 mice were divided into control and CsA-treated groups. Before and after hindlimb ischemia was induced, circulating EPC number and serum levels of different cytokines were measured. Compared with the controls, CsA treatment significantly increased the blood levels of stroma-derived factor-1α and stem cell factor after ischemic stress ( P < 0.001). The CsA group displayed a significant increase in the number of circulating EPCs (sca-1+KDR+ and c-kit+CD31+ EPCs, both P < 0.05). In vivo, CsA caused a significant increase in the numbers of EPCs incorporated into the Matrigel and ischemic limbs ( P < 0.05). In the peripheral blood, CsA significantly decreased CD26+ cell numbers and attenuated the plasma CD26/DPP IV activity ( P < 0.001). Furthermore, short-term CsA treatment significantly improved the perfusion of ischemic limbs and decreased the spontaneous digital amputation rate. In summary, CsA manipulates the mobilization of EPCs into the circulation via the CD26/DPP IV system. Short-term CsA treatment has beneficial effects on angiogenesis of ischemic tissues.

Successful in vivo propagation of factor IX-producing hepatocytes in mice: Potential for cell-based therapy in haemophilia B

2008 ◽  
Vol 99 (11) ◽  
pp. 883-891 ◽  
Author(s):  
Kohei Tatsumi ◽  
Miho Kataoka ◽  
Masaru Shibata ◽  
Hiroyuki Naka ◽  
Midori Shima ◽  
...  
Keyword(s):  
Coagulation Factor ◽  
Isolated Hepatocytes ◽  
Factor Ix ◽  
Blood Levels ◽  
Recipient Mouse ◽  
Cytoplasmic Staining ◽  
Haemophilia B ◽  
Cell Based Therapy ◽  
Coagulation Factor Ix

SummaryCell-based therapies using isolated hepatocytes have been proposed to be an attractive application in the treatment of haemophilia B due to the normal production of coagulation factor IX (FIX) in these particular cells. Current cell culture technologies have largely failed to provide adequate isolated hepatocytes, so the present studies were designed to examine a new approach to efficiently proliferate hepatocytes that can retain normal biological function, including the ability to synthesize coagulation factors like FIX. Canine or human primary hepatocytes were transplanted into urokinase-type plasminogen activatorsevere combined immunodeficiency (uPA/SCID) transgenic mice. Both donor hepatocytes from canines and humans were found to progressively proliferate in the recipient mouse livers as evidenced by a sharp increase in the circulating blood levels of species-specific albumin, which was correlated with the production and release of canine and human FIX antigen levels into the plasma. Histological examination confirmed that the transplanted canine and human hepatocytes were able to proliferate and occupy >80% of the host livers. In addition, the transplanted hepatocytes demonstrated strong cytoplasmic staining for human FIX, and the secreted coagulation factor IX was found to be haemostatically competent using specific procoagulant assays. In all, the results from the present study indicated that developments based on this technology could provide sufficient FIX-producing hepatocytes for cell-based therapy for haemophilia B.

Geometric modeling, functional parameter calculation, and visualization of the in-vivo distended rectal wall

2006 ◽  
Author(s):  
Clifton R. Haider ◽  
Armando Manduca ◽  
Jon J. Camp ◽  
Joel G. Fletcher ◽  
Richard A. Robb ◽  
...  
Keyword(s):  
Geometric Modeling ◽  
Rectal Wall ◽  
Functional Parameter ◽  
Parameter Calculation

Abstract 1021: In Vivo Immune Response To Allogeneic Porcine Mesenchymal Stem Cell (msc) Transplantation: A 12-day Course Of Fk-506 Abbrogates Humoral Response.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Alain J Poncelet ◽  
Johnatan Vercruysse ◽  
Alain Saliez ◽  
Pierre Gianello
Keyword(s):  
Stem Cell ◽  
Humoral Response ◽  
Control Group ◽  
Blood Levels ◽  
Study Group ◽  
Fk 506 ◽  
Allogeneic Mscs ◽  
Cytotoxic Response ◽  
Humoral Responses

Purpose Several reports have highlighted the low immunogenic profile of MSCs. Therefore, we decided to test in vivo the humoral response to allogeneic MSCs transplantation and the effect of transient immunosuppression in a porcine model. Methods/Material MHC-controlled mini-swine SLA cd and SLA dd were used as donor and recipients, respectively. Two sites of transplantation were selected: subcutaneous and intracardiac. In our control group (n = 5), animals received no immunosuppression. In the study group (n = 11), nearly 1 x 10 6 allogeneic MSC/kg were injected. FK-506 was given from day 0 –12 and adjusted to therapeutic blood levels. Sera were serially collected up to one year after transplantation. The presence of specific anti-donor IgM and IgG was tested by flow cytometry and by a complement-mediated cytotoxicity assay. Results In the control group, all animals developed humoral responses in both IgM/G classes that persisted up to ten weeks. When transplanted subcutaneously, a single injection failed to elicit a complement-mediated cytotoxic response but subsequent re-challenge did. In the study group, only 2/11 FK-treated animals developed a transient humoral response, both in IgM and IgG, whereas all others failed to develop donor-specific antibodies. However, none of the sera tested from those 11 animals could elicit a complement-mediated cytotoxic response. Conclusion Allogeneic MSCs injected subcutaneously or intra-cardially can elicit prolonged humoral responses despite their putative low immunogenic profile. As already shown for experimental allogeneic organ transplantation, a transient immunosuppressive regimen can overcome the initial B cell response. Our result suggests that in vitro and in vivo characteristics of MSCs might differ and emphasizes the importance of pursuing research on allogeneic stem cell transplantation.

Effect of free fatty acids on blood amino acid levels in human

1986 ◽  
Vol 250 (6) ◽  
pp. E686-E694 ◽  
Author(s):  
E. Ferrannini ◽  
E. J. Barrett ◽  
S. Bevilacqua ◽  
R. Jacob ◽  
M. Walesky ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Insulin ◽  
Plasma Free Fatty Acid ◽  
Blood Levels ◽  
Experimental Conditions ◽  
Lipid Infusion ◽  
Amino Acid Levels ◽  
Branched Chain

Raised plasma free fatty acid (FFA) levels effectively impede glucose uptake in vivo, thereby conserving plasma glucose and sparing glycogen. To test whether FFA have any effect on blood amino acid levels, we infused Intralipid plus heparin or saline into healthy volunteers under four different experimental conditions: A) overnight fast; B) euglycemic hyperinsulinemia (approximately 100 microU/ml); C) hyperglycemic (approximately 200 mg/100 ml) hyperinsulinemia (approximately 50 microU/ml); and D) hyperglycemic (approximately 300 mg/100 ml) normoinsulinemia (approximately 20 microU/ml). In the fasting state (A), lipid infusion was associated with lower blood levels of most amino acids, both branched chain and glucogenic. This effect, however, could not be ascribed to lipid infusion alone, because plasma insulin levels were also stimulated. The clamp studies (B, C, and D) allowed to assess the influence of lipid on blood amino acid levels at similar plasma insulin and glucose levels. It was thus observed that lipid infusion has a significant hypoaminoacidemic effect of its own under both euglycemic (B) and hyperglycemic (C) conditions; this effect involved many glucogenic amino acids (alanine, glycine, phenylalanine, serine, threonine, and cystine) but none of the branched-chain amino acids (leucine, isoleucine, and valine). In marked contrast, normoinsulinemic hyperglycemia (D), with or without lipid infusion, caused no change in the blood level of any measured amino acid. We conclude that lipid infusion has a hypoaminoacidemic action. We also suggest that this action is permitted by insulin and may involve specific metabolic interactions (e.g., reduced availability of glucose-derived pyruvate or glycerophosphate) as well as enhanced uptake by the liver.

scholarly journals Development of Asialoglycoprotein Receptor-Targeted Nanoparticles for Selective Delivery of Gemcitabine to Hepatocellular Carcinoma

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4566 ◽  
Author(s):  
Anroop B. Nair ◽  
Jigar Shah ◽  
Bandar E. Al-Dhubiab ◽  
Snehal S. Patel ◽  
Mohamed A. Morsy ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Histopathological Examination ◽  
Chitosan Nanoparticles ◽  
Physicochemical Characteristics ◽  
Blood Levels ◽  
Selective Targeting ◽  
Selective Delivery ◽  
Galactosylated Chitosan ◽  
Biphasic Release

Selective targeting of anticancer drugs to the tumor site is beneficial in the pharmacotherapy of hepatocellular carcinoma (HCC). This study evaluated the prospective of galactosylated chitosan nanoparticles as a liver-specific carrier to improve the therapeutic efficacy of gemcitabine in HCC by targeting asialoglycoprotein receptors expressed on hepatocytes. Nanoparticles were formulated (G1–G5) by an ionic gelation method and evaluated for various physicochemical characteristics. Targeting efficacy of formulation G4 was evaluated in rats. Physicochemical characteristics exhibited by nanoparticles were optimal for administering and targeting gemcitabine effectively to the liver. The biphasic release behavior observed with G4 can provide higher drug concentration and extend the pharmacotherapy in the liver target site. Rapid plasma clearance of gemcitabine (70% in 30 min) from G4 was noticed in rats with HCC as compared to pure drug (p < 0.05). Higher uptake of gemcitabine predominantly by HCC (64% of administered dose; p < 0.0001) demonstrated excellent liver targeting by G4, while mitigating systemic toxicity. Morphological, biochemical, and histopathological examination as well as blood levels of the tumor marker, alpha-fetoprotein, in rats confirmed the curative effect of G4. In conclusion, this study demonstrated site-specific delivery and enhanced in vivo anti-HCC efficacy of gemcitabine by G4, which could function as promising carrier in hepatoma.

IN VITRO DEMONSTRATION OF "HEPARIN REBOUND"

1987 ◽  
Author(s):  
C Taylor ◽  
R F Baugh
Keyword(s):  
Whole Blood ◽  
Cardiovascular Surgery ◽  
Anticoagulant Activity ◽  
Blood Levels ◽  
In Vitro Test ◽  
Neutralizing Activity ◽  
Vitro Test ◽  
The Stability

"Heparin rebound", the in vivo appearance of measurable heparin anticoagulant activity following theapparent neutralization of heparin by protamine, hasbeen a problem sporadically associated with the use of heparin in cardiovascular surgery. A number of mechanisms have been proposed to explain rebound, and to some extent each may contribute to the phenomena. As yet no reliable, predictable method has been demonstrated for measuring, reproducing or quantifying "heparin rebound".We have demonstrated and measured the appearance of heparin anticoagulant activity following neutralization with protamine in citrated whole blood. The reappearance of heparin anticoagulant activity was associated with a rapid loss of protamine. The loss of protamine followed 1st order enzyme kinetics, and was indicative of the action of an enzyme. The anticoagulant activity which eappeared could be titrated againwith protamine. The loss of protamine neutralizing activity, in whole blood, could be followed by titration with heparin using a recalcified activated clotting time. The rate of loss varied with both individual blood donors and with the type and source of protamine. The rate of loss of protamine was great enough to influence in. vivo heparin/protamine neutralization ratios, i.e. at 4 units of heparin/ml, 1 unit/ml anticoagulant activity was routinely recovered within 30 minutes following initial neutralization. The indications for cardiovascular surgery are:1)the in vivo neutralization ratio should be adjusted to account for loss of protamine activity, 2) the higherthe blood levels of heparin used during surgery, themore significant the potential for heparin rebound, and 3) protamines may be evaluated in an in vitro test which measures the stability of protamine neutralizing activity in whole blood.

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