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Daniel P. Toews - One of the best experts on this subject based on the ideXlab platform.
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The dynamics of venous return and response to hypervolemia in the toad, Bufo marinus (L.).
BMC Physiology, 2001Co-Authors: Erin E Killorn, Daniel P. ToewsAbstract:Background Venous return from the posterior region of amphibians travels by either two renal Portal veins to the kidney or a central abdominal vein that drains into the Hepatic Portal System. The relative proportions of blood flow in these vessels has never been measured nor has a modification of flow been determined when venous return increases by changes in blood volume during hypervolemia or during increased volume input from the posterior lymph hearts.
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The dynamics of venous return and response to hypervolemia in the toad, Bufo marinus (L.)
BMC Physiology, 2001Co-Authors: Erin E Killorn, Daniel P. ToewsAbstract:Background Venous return from the posterior region of amphibians travels by either two renal Portal veins to the kidney or a central abdominal vein that drains into the Hepatic Portal System. The relative proportions of blood flow in these vessels has never been measured nor has a modification of flow been determined when venous return increases by changes in blood volume during hypervolemia or during increased volume input from the posterior lymph hearts. Results Venous return from the posterior region of Bufo marinus was measured under resting conditions and in response to a Systemic hypervolemia. Doppler flow probes were positioned on the renal Portal and ventral abdominal veins, and flow was recorded as injections of artificial plasma equaling 100% of the animal's plasma volume were administered through the sciatic artery. Resting flow was found to be 5.54 ± 2.03 ml min^-1 kg^-1 in the paired renal Portal veins, and 7.31 ± 0.89 ml min^-1 kg^-1 in the ventral abdominal vein. While renal Portal flow was found to increase by a factor of 2.4 times during the first 10 min of hypervolemia, ventral abdominal flow only increased by a factor of 1.3. Conclusions Our results quantify the contribution to circulation from posterior venous return in the toad Bufo marinus. A preferential movement of excess fluid through the renal Portal pathway was also demonstrated, supporting the possibility of water elimination via the renal Portal circulation, especially during periods of high water influx into the animals.
Erin E Killorn - One of the best experts on this subject based on the ideXlab platform.
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The dynamics of venous return and response to hypervolemia in the toad, Bufo marinus (L.).
BMC Physiology, 2001Co-Authors: Erin E Killorn, Daniel P. ToewsAbstract:Background Venous return from the posterior region of amphibians travels by either two renal Portal veins to the kidney or a central abdominal vein that drains into the Hepatic Portal System. The relative proportions of blood flow in these vessels has never been measured nor has a modification of flow been determined when venous return increases by changes in blood volume during hypervolemia or during increased volume input from the posterior lymph hearts.
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The dynamics of venous return and response to hypervolemia in the toad, Bufo marinus (L.)
BMC Physiology, 2001Co-Authors: Erin E Killorn, Daniel P. ToewsAbstract:Background Venous return from the posterior region of amphibians travels by either two renal Portal veins to the kidney or a central abdominal vein that drains into the Hepatic Portal System. The relative proportions of blood flow in these vessels has never been measured nor has a modification of flow been determined when venous return increases by changes in blood volume during hypervolemia or during increased volume input from the posterior lymph hearts. Results Venous return from the posterior region of Bufo marinus was measured under resting conditions and in response to a Systemic hypervolemia. Doppler flow probes were positioned on the renal Portal and ventral abdominal veins, and flow was recorded as injections of artificial plasma equaling 100% of the animal's plasma volume were administered through the sciatic artery. Resting flow was found to be 5.54 ± 2.03 ml min^-1 kg^-1 in the paired renal Portal veins, and 7.31 ± 0.89 ml min^-1 kg^-1 in the ventral abdominal vein. While renal Portal flow was found to increase by a factor of 2.4 times during the first 10 min of hypervolemia, ventral abdominal flow only increased by a factor of 1.3. Conclusions Our results quantify the contribution to circulation from posterior venous return in the toad Bufo marinus. A preferential movement of excess fluid through the renal Portal pathway was also demonstrated, supporting the possibility of water elimination via the renal Portal circulation, especially during periods of high water influx into the animals.
José Aristodemo Pinotti - One of the best experts on this subject based on the ideXlab platform.
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Presence of air in the Hepatic Portal System in association with umbilical venous catheter malposition
2014Co-Authors: José Aristodemo, José Aristodemo PinottiAbstract:Alvares BR, Stopiglia MCS, Mezzacappa MA. Presence of air in the Hepatic Portal System in association with umbilical venous cat heter malposition. RadiolBras. 2014 Jan/Fev;47(1):49–50.AbstractResumoThe authors report a case of umbilical venous catheter malposition with air in the Portal venous System in a preterm neonate. I nitially, thehypothesis of necrotizing enterocolitis was considered, but the newborn progressed with no finding of disease and the air disap peared atfollow-up radiography. The differential diagnosis of such a finding can avoid unnecessary clinical treatments.Keywords: Umbilical venous catheter; Newborn; Portal air; Necrotizing enterocolitis; Radiological study.Apresentamos um caso relacionado a cateter umbilical venoso mal posicionado, associado a presenca de ar no sistema Portal, em u mrecem-nascido prematuro. A hipotese de enterocolite necrosante foi considerada inicialmente, porem o recem-nascido evoluiu semachados da doenca, tendo o ar desaparecido em radiografia de controle. O diagnostico diferencial deste achado evita condutas cl inicasdesnecessarias.Unitermos: Cateter umbilical venoso; Recem-nascido; Ar Portal; Enterocolite necrosante; Exame radiologico.
Piotr Fiedor - One of the best experts on this subject based on the ideXlab platform.
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Surgical removal of the pancreas with one-step autotransplantation of isolated Langerhans islets into the Hepatic Portal System in the pig.
Polskie Archiwum Medycyny Wewnetrznej-polish Archives of Internal Medicine, 2009Co-Authors: K Pawelec, M.t. Juszczak, Andrzej Kinasiewicz, Marek Sabat, Krystyna Szymańska, Zbigniew Wierzbicki, Piotr FiedorAbstract:INTRODUCTION Autotransplantation of isolated Langerhans islets is regarded as the only way to prevent iatrogenic diabetes in patients who had been scheduled for pancreatectomy due to painful chronic pancreatitis. A sufficient number of Langerhans islets capable of secretory activity need to be transplanted to maintain normoglycemia after the surgical procedure. In order to optimize all stages, including collection, storage, isolation and transplantation of pancreatic islets, a reproducible animal-based experimental model should be developed before a new method is introduced into clinical practice.OBJECTIVES The aim of the present study was to develop a reproducible autogenic model-based method for collection, conservation and isolation of porcine pancreas so that transplantation of isolated pancreatic islets could be performed and postoperative normoglycemia achieved.MATERIAL AND METHODS Pigs were subjected to total pancreatectomy with simultaneous splenectomy and without removal of the duodenum. The collected pancreas was stored in the University of Wisconsin solution with the addition of pentoxifylline (PTX) until the isolation procedure (
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surgical removal of the pancreas with one step autotransplantation of isolated langerhans islets into the Hepatic Portal System in the pig
Polskie Archiwum Medycyny Wewnetrznej-polish Archives of Internal Medicine, 2009Co-Authors: K Pawelec, M.t. Juszczak, Andrzej Kinasiewicz, Marek Sabat, Krystyna Szymańska, Zbigniew Wierzbicki, Piotr FiedorAbstract:INTRODUCTION Autotransplantation of isolated Langerhans islets is regarded as the only way to prevent iatrogenic diabetes in patients who had been scheduled for pancreatectomy due to painful chronic pancreatitis. A sufficient number of Langerhans islets capable of secretory activity need to be transplanted to maintain normoglycemia after the surgical procedure. In order to optimize all stages, including collection, storage, isolation and transplantation of pancreatic islets, a reproducible animal-based experimental model should be developed before a new method is introduced into clinical practice.OBJECTIVES The aim of the present study was to develop a reproducible autogenic model-based method for collection, conservation and isolation of porcine pancreas so that transplantation of isolated pancreatic islets could be performed and postoperative normoglycemia achieved.MATERIAL AND METHODS Pigs were subjected to total pancreatectomy with simultaneous splenectomy and without removal of the duodenum. The collected pancreas was stored in the University of Wisconsin solution with the addition of pentoxifylline (PTX) until the isolation procedure (<4 hours). Efficacy of isolation was evaluated based on the number, quality and viability of obtained islets. Following autotransplantation into the liver, secretory activity of the islets was assessed intravitally by serum glucose monitoring.RESULTS The islet yield per gram of pancreas was 1452 (standard deviation [SD] +/- 125) for the PTX group and 384 (SD +/- 115) for the control non-PTX group (p < 0.01). Viability of islets for individual isolations did not reveal any statistically significant differences between groups and was estimated at 85-93%. Three out of five animals demonstrated normoglycemia with features of neoangiogenesis in the islets transplanted into the liver, which was confirmed by histological examination. One animal developed hyperglycemia up to 430 mg/dl, and histological image showed intensive apoptosis and degranulation in the transplanted islets.CONCLUSIONS Efficacy of the isolation method was confirmed by achieving normoglycemia after autotransplantation of pancreatic islets into the liver, while histological examination showed Hepatic vascularization to be the most appropriate location for an autogenic graft. PTX presence in the preserving solution for the pancreas storage produced the cytoprotective effect, which directly correlated with the islet yield.
David L. Williams - One of the best experts on this subject based on the ideXlab platform.
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The disulfide redox System of Schistosoma mansoni and the importance of a multifunctional enzyme, thioredoxin glutathione reductase.
Molecular and Biochemical Parasitology, 2002Co-Authors: Heather M. Alger, David L. WilliamsAbstract:Schistosoma mansoni, a causative agent of schistosomiasis, is a major cause of human morbidity in tropical countries. Adult schistosomes, which reside in the Hepatic Portal System, are exposed to reactive oxygen compounds through respiration and as a result of the host immune response. To minimize oxidative stress schistosomes must possess adequate mechanisms of detoxification. Major detoxification Systems rely on reducing equivalents from the disulfide oxidoreductases glutathione and thioredoxin. Therefore, maintenance of adequate levels of these thiols in a reduced form is critical. Here we show that S. mansoni possess an unusual thiol redox System centered on thioredoxin glutathione reductase. This enzyme represents an unusual fusion of a pyridine nucleotide disulfide oxidoreductase with a redox active glutaredoxin extension. Furthermore, we predict that this is a selenocysteine protein. Immunoprecipitation, western blot and inhibitor studies show that this protein has thioredoxin reductase, glutathione reductase, and glutaredoxin activities. Most importantly, we show that thioredoxin glutathione reductase appears to be the major, if not the sole enzyme for these activities in adult worms, completely replacing thioredoxin reductase and glutathione reductase. This is the first example of an organism with a redox System based exclusively on thioredoxin glutathione reductase.
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the disulfide redox System of schistosoma mansoni and the importance of a multifunctional enzyme thioredoxin glutathione reductase
Molecular and Biochemical Parasitology, 2002Co-Authors: Heather M. Alger, David L. WilliamsAbstract:Schistosoma mansoni , a causative agent of schistosomiasis, is a major cause of human morbidity in tropical countries. Adult schistosomes, which reside in the Hepatic Portal System, are exposed to reactive oxygen compounds through respiration and as a result of the host immune response. To minimize oxidative stress schistosomes must possess adequate mechanisms of detoxification. Major detoxification Systems rely on reducing equivalents from the disulfide oxidoreductases glutathione and thioredoxin. Therefore, maintenance of adequate levels of these thiols in a reduced form is critical. Here we show that S . mansoni possess an unusual thiol redox System centered on thioredoxin glutathione reductase. This enzyme represents an unusual fusion of a pyridine nucleotide disulfide oxidoreductase with a redox active glutaredoxin extension. Furthermore, we predict that this is a selenocysteine protein. Immunoprecipitation, western blot and inhibitor studies show that this protein has thioredoxin reductase, glutathione reductase, and glutaredoxin activities. Most importantly, we show that thioredoxin glutathione reductase appears to be the major, if not the sole enzyme for these activities in adult worms, completely replacing thioredoxin reductase and glutathione reductase. This is the first example of an organism with a redox System based exclusively on thioredoxin glutathione reductase. # 2002 Elsevier Science B.V. All rights reserved.