Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sublethal doses of vincristine (VNC) and bacterial lipopolysaccharide (LPS) administered simultaneously to adult male mice resulted in markedly enhanced mortality. All of 10 strains of Pseudomonas aeruginosa tested, 4 of 7 strains of Bacteroides, and 6 of 10 strains of Listeria monocytogenes were able to substitute for purified LPS in enhancing mortality in VNC-treated mice. Inoculation of mice with each of 10 strains of Pseudomonas, each of 7 strains of Bacteroides, and about half of the 10 strains of Listeria tested elicited increased resistance to the lethal action of purified LPS. The patterns of responses of mice receiving a lethal combination of 2 mg of LPS/kg and 1 mg of VNC/kg resembled those of mice receiving a lethal dose of 10 mg of VNC/kg alone or 15 mg of LPS/kg alone with respect to (i) serum glutamic pyruvate transaminase activity, (ii) hematocrit values, and (iii) thrombocytopenia. The patterns of responses of mice receiving a lethal combination of LPS and VNC resembled those of mice receiving a lethal dose of LPS alone with respect to (i) hypothermia, (ii) retention of sulfobromophthalein, (iii) fibrinogen level, (iv) prothrombin activity, (v) blood urea nitrogen levels, and (vi) time of death. These data are consistent with the proposition that the combination of VNC and LPS produces a fatal renal failure. Histological studies confirmed that there was extensive renal damage in mice treated with lethal doses of LPS alone or a lethal combination of LPS and VNC.
 ...
PMID:Enhanced toxicity for mice of combinations of bacterial lipopolysaccharide and vincristine. 94 80

Disposal of heparin is accomplished rapidly by the normal liver, but the effects of ischemia, flushing and hypothermia during hepatic transplantation have not been investigated before. The results of the present study showed that neither laparotomy, hypothermia nor insertion of the portosystemic bypass seemed markedly to affect the coagulation profile, but autograft associated with 30 to 45 minutes of warm ischemia resulted in a twofold prolongation of the t1/2 heparin as calculated from sequential measurements of the activated clotting time. Unexpectedly, the storage of livers for four hours in EuroCollins solutions seemed to result in more rapid disappearance of heparin than in animals after laparotomy. After hepatectomy, the clearance of heparin was delayed for two hours but, thereafter, the slope of the disappearance resembled that in sham operated animals. Autograft and allograft of livers in normal pigs that did not receive transfusion were also associated with changes in fibrinolysis and declining levels of fibrinogen together with severe intraoperative bleeding problems and rapid death on the operating table in 30 per cent of the pigs. While administration of heparin alone did not appear to precipitate these changes, use of the drug after dissection, mobilization and storage of the liver may release other tissue factors that activate fibrinolysis.
 ...
PMID:Heparin as the cause of coagulopathy which may complicate grafting of the liver. 180 3

We evaluated a technique for treating hypothermia that uses extracorporeal circulation but does not require heparin or pump assistance. Hypothermia to 29.5 degrees C was induced in eight anesthetized dogs, and thermistors placed in the pulmonary artery, liver, bladder, esophagus, rectum, muscle, and skin. Four experimental animals were rewarmed by creating a fistula which connected arterial and venous femoral lines to an interposed counter-current heat exchanger. External rewarming was used in four controls. Bleeding time (BT), coagulation profile (PT, PTT, TT), and cardiac output (CO) were measured during rewarming. Core temperature (T) rose significantly faster with CAVR (0.00001). Average time to rewarming was 45 min, vs. 4 hrs in controls. Haptoglobin, platelet, fibrinogen, and fibrin split product levels were unaffected. Continuous arteriovenous rewarming (CAVR) improved T, CO, BT, and coagulation profile faster than any method yet reported not requiring heparin or cardiac bypass. The application of CAVR in post-traumatic hypothermia warrants further investigation.
 ...
PMID:Continuous arteriovenous rewarming: experimental results and thermodynamic model simulation of treatment for hypothermia. 225 54

In an attempt to assess the changes occurring to the coagulation profile during internal active core rewarming with partial cardiopulmonary bypass (CPB) without heparin anticoagulation, five pigs were anesthetized, and a model for severe to moderate hypothermia was created. Femoral-femoral bypass with Bio-Pump, heat exchanger, and a membrane oxygenator were used during the rewarming for 64.8 +/- 8.5 minutes. There were no statistically significant changes in platelet count, platelet index, activated clotting time (ACT), partial thromboplastin time (PTT), prothrombin time (PT), fibrinogen, fibrinogen index and fibrin split products (p greater than 0.05). There were no thromboembolic sequelae seen at autopsy. The components of the CPB circuit showed no signs of formation of aggregates or thrombi. The results of this study are attributed to the nonthrombogenic, atraumatic design of the Bio-Pump and the enhanced physiological fibrinolysis seen in the first hour of CPB. We concluded that heparinless CPB may serve as a safe alternative for active core rewarming for severe to moderate hypothermia.
 ...
PMID:Heparinless extracorporeal bypass for treatment of hypothermia. 229 71

Puppies 6-12 kg underwent cardiopulmonary bypass with profound hypothermia. Thirteen animals received 200 ng kg-1 min-1 of PGI2 during bypass whilst 11 control animals received equivalent volumes of glycine buffer (placebo) over a similar period. Results indicated preservation of platelets, leukocytes and fibrinogen levels, together with shortened activated partial thromboplastin times and fewer fibrinogen degradation products post-bypass in PGI2-treated animals. There was an initial fall in blood pressure and systemic vascular resistance in PGI2 treated animals, but pulmonary pressures and resistances, cardiac outputs, and heart rates showed no significant differences from controls. Higher and more satisfactory end of bypass and post-bypass blood pressure levels, together with a lesser fall-off in mean total pulmonary compliance, and shortened bypass times were achieved in treated animals. PGI2 appeared to afford some protection against lung damage as observed by histological studies. All beneficial effects appeared to be significantly greater amongst smaller animals. The results indicate possible benefits from the use of PGI2 in infant open heart surgery.
 ...
PMID:The effects of prostacyclin (PGI2) on haematological and haemodynamic parameters, and lung histology in puppies undergoing cardiopulmonary bypass surgery with profound hypothermia. 388 67

A number of hemostasis parameters were studied in a total of 63 patients undergoing cardiopulmonary bypass (CPB) for open heart surgery. In 33 patients fibrinogen, Factors II, V, VIII:C, X, XI, antithrombin, plasminogen, alpha 2-antiplasmin, and platelet counts were assayed before surgery, during maximal hypothermia, at the end of the bypass procedure, before and after protamine sulfate infusion, in the intensive care unit, and 48 hours postoperatively. All factors assayed decreased markedly when the patients were placed on the bypass machine, the drop fairly well paralleling the decrease in hematocrit. During bypass the factors remained low, although a slight tendency toward an increase was noted. Only platelet counts remained low with a decreasing trend until the end of bypass. In the intensive care unit a second decrease in fibrinogen, Factors II and V and antithrombin was noted. This drop was unrelated to four patients who experienced a greater blood loss during this time than the others. Forty-eight hours postoperatively, a marked increase could be found in all clotting factors and near normal levels were measured. Platelet counts remained low, however. The decrease in factors rarely dropped into a range where one would expect a compromised hemostasis (less than 30%). Although antithrombin levels decreased below 60%, no difficulties with heparinization were encountered. Several factors were assayed manually and by automated analyzer (Multistat III), and excellent correlations were found between both procedures. Also a good correlation was found between the activated whole blood clotting times and quantitative heparin assays. In 30 additional patients platelet function was studied before surgery, after thoracotomy, after heparin administration, after initiation of bypass, at maximal hypothermia, before and after protamine sulfate infusion, and 24 hours postoperatively. Platelet counts once again decreased as patients were placed on the CPB machine and remained low throughout the procedure. Mean platelet volumes were unchanged until protamine was given. At that time, a significant drop in mean platelet volume was recorded. Twenty-four hours postoperatively the volumes were normal again. Platelet aggregation studies were performed on a whole blood aggregometer using two concentrations of ADP, collagen, and ristocetin as aggregation inducers. A significant decrease in aggregability was seen when the patients were connected to the CPB apparatus.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Hemostasis changes during cardiopulmonary bypass surgery. 404 52

Blood has a number of rheological properties which partially determine flow, especially at capillary level, and its capacity to deliver oxygen. It is non-Newtonian, pseudoplastic, thixotropic and viscoelastic. Viscosity can be studied with different types of viscosimeters (coaxial cylinder or capillary viscosimeters). It can be defined by the ratio of stress of deformation to rate of deformation. Viscosity depends on macrorheological parameters: hematocrit, serum proteins, especially fibrinogen and globulins, and also on microrheological parameters: degree of aggregation and red blood cell deformability. Viscosity rises when the temperature falls and decreases with the radius of the tube through which the blood flows (Fahraeus-Linqvist effects). Blood viscosity is studied clinically at different temperatures, and, above all, at different rates of deformation by carefully recording the hematocrit. Plasma viscosity, fibrinogen, albumia and immunoglobulin levels, the viscosity of blood cell suspensions in normal saline must also be taken into consideration. Special investigations (rheoscopy, filtrability) provide information about red cell aggregation and deformability. Hyperviscosity syndromes are observed with: --raised hematocrit (polycythemia and pseudopolycythemia), --conditions with raised serum proteins or changes in their composition (especially hyperfibrinogenemia, raised immunoglobulins, low albumin levels); inflammatory syndromes, dysglobulinemias (Fahey's syndrome of plasma hyperviscosity), --low temperature (hypothermia), --increased red cell aggregability (shock, fat embolism), --reduced red cell deformability due to various congenital and acquired conditions (sickle cell anemia, renal failure, hyperlipoproteinemia, thrombosis, diabetes). Conversely, hypoviscosity may occur with a low hematocrit, hypoproteinemia, hypofibrinogenemia, and hyperthermia. Increased viscosity results in a slowing of blood flow, stagnation of its constituents and in ischemia. Therapeutic interventions may be considered on the different components of the hyperviscosity syndrome: hemodilation, plasmapheresis, dispersion of aggregants, agents acting on red cell deformability.
 ...
PMID:[Blood hyperviscosity syndromes. Classification and physiopathological understanding. Therapeutic deductions]. 636 7

In the present study, an effort was made to establish the procedure for 60 minutes selective profound hypothermia below 20 degrees C of the abdominal viscera. In 6 mongrel dogs, hemodynamic changes were investigated during 60 minutes normothermic vascular exclusion of the abdominal viscera by occluding the aorta and inferior caval vein just above the diaphragm. Hemodynamic state just after the combined occlusion of these vessels was stable, but 60 minutes occlusion was followed by hypoperfusion of the cranial half of the body. In 15 mongrel dogs, the 60 minutes selective profound hypothermia below 20 degrees C of the abdominal viscera was performed after occluding these vessels with an aid of extracorporeal circuit. Pooled blood in the splanchnic region during hypothermia was warmed and drained to jugular vein to maintain the hemodynamic state in the cranial half of the body. Twelve of 15 dogs survived 2 weeks after the procedure with minimal hepatic damage. In 7 mongrel dogs, blood coagulation system was investigated. Decrease of platelet, fibrinogen, plasminogen, anti-thrombin III, prothrombin and cold insoluble globulin concentration, elongation of prothrombin time and partial thromboplastin time, and elevation of FDP occurred during and after the selective profound hypothermia. But these changes were self limiting and recovered soon after heparin neutralization. In 9 mongrel dogs, extended pancreatectomy with splenectomy and combined resection of portal vein using selective profound hypothermia was performed. Bleeding and splanchnic congestion during extended pancreatectomy was minimum. Five of 9 dogs survived 2 weeks with slight hepatic and renal damage.
 ...
PMID:[Experimental studies on the selective profound hypothermia of the abdominal viscera by descending aorta and inferior caval vein occlusion]. 667 63

The effects of prostacyclin on whole blood platelet count, blood coagulation factors, and postoperative bleeding were investigated in 20 patients undergoing aorta-coronary bypass. Eleven patients received heparin 2 mg/kg and prostacyclin 50 ng/kg/min during cardiopulmonary bypass (CPB). Nine patients received only heparin 3 mg/kg. CPB was by roller pump and bubble oxygenator primed with Ringer's acetate. Hypothermia to 28 degrees C was induced. In the control group, platelet count, corrected for hemodilution, was 70% +/- 15% (mean +/- SD) of pre-CPB value after 30 minutes of bypass and remained at this level 1 hour after CPB. In the prostacyclin group, the platelet count after 30 minutes was 85% +/- 17%, after 120 minutes 111% +/- 20%, and 1 hour after CPB 92% +/- 17%. There was a significant difference between the groups (p less than 0.05) from 60 minutes of CPB up to 1 hour after CPB. Prostacyclin allowed reduction of the heparin dosage while retaining anticoagulation as measured by activated coagulation time (ACT), fibrinopeptide A, and fibrinogen determinations. The ACT was more than 900 seconds in the prostacyclin group after 30 minutes of CPB, as compared to 523 +/- 118 seconds (p less than 0.05) in the control group. This difference diminished later during CPB. In the prostacyclin group, arterial blood pressure was 30 mm Hg or less during the first hour of CPB and the systemic vascular resistance was half of that in the control group. All patients survived. There were no clinical signs of neurologic damage. Postoperative bleeding was 352 +/- 61 ml in the prostacyclin group and 550 +/- 338 ml (NS) in the control group.
 ...
PMID:Prostacyclin infusion during extracorporeal circulation foe coronary bypass. 703 54

The haemostatic status of twenty children with cyanotic and acyanotic cardiopathies was studied before, during and after cardiopulmonary bypass (CPB) under deep hypothermia and haemodilution. Eleven patients had various haemostatic troubles before surgery. Haemodilution with a crystalloid solution to an haematocrit of 21,8 vol. +/- 1,3% resulted in a severe lowering of all coagulation factors. Forced diuresis after CPB induced partial normalization. The observed alterations included moderate thrombocytopenia, prolongation of the prothrombin time, transient decrease of factors V and plasminogen, elevation of fibrin degradation products (FDP), significant lowering of factor VII-X, marked elevation of factor VIII and mild increase of fibrinogen. No correlation was found between coagulation abnormalities and postoperative bleeding, duration of CPB or type of cardiopathies. It is concluded that CPB with haemodilution proves as safe as more conventional approaches in respect to coagulant activities.
 ...
PMID:Haemostatic changes during open heart surgery with extracorporeal circulation and deep hypothermia in children. 708 21


1 2 3 4 5 6 7 Next >>