Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.6 (thromboplastin)
 13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A patient with von Willebrand's disease having aortic valve replacement was managed with cryoprecipitate infusions and monitoring of factor VIII levels. This disorder is associated with low factor VIII levels and abnormal platelet function. There may be no history of bleeding, as the severity of the bleeding tendency varies greatly and fluctuates temporally. The partial thromboplastin time is frequently prolonged, but more detailed studies are necessary to establish a diagnosis (bleeding time, platelet adhesiveness to glass beads and ristocetin, von Willebrand's antigen, ristocetin-von Willebrand's factor, and factor VIII clotting activity). Elevation of factor VIII levels to 50 to 100% of normal allows adequate clotting and is best accomplished with cryoprecipitate or fresh frozen plasma rather than commercial concentrates of factor VIII, whose activity is unpredictable.
J Thorac Cardiovasc Surg 1978 Aug
PMID:Aortic valve replacement in von Willebrand's disease. 30 20

To evaluate the potential effect of aspirin, a platelet inhibitory agent, on postoperative bleeding complications after coronary artery bypass graft surgery, we compared each of nine patients who had taken aspirin within 7 days prior to operation to one or two control subjects (total 16 patients) matched for age, sex, extent of coronary disease, number of grafts placed total operative time, bypass time, and preoperative use of propranolol. Preoperative prothrombin time, partial thromboplastin time, and platelet counts were normal for all patients. Mean mediastinal blood loss was significantly greater in the aspirin group (919 +/- 164 ml., S.E.) than in the control group (437 +/- 61 ml., p less than 0.001). The degree of mediastinal blood loss did not correlate with patient age, total operative time, bypass time, number of vessels diseased, or grafts placed. In addition, compared to controls the aspirin group required prolonged chest tube drainage (33 +/- 5 hours versus 19 +/- 1 hour, p less than 0.001).
J Thorac Cardiovasc Surg 1978 Nov
PMID:Relation of preoperative use of aspirin to increased mediastinal blood loss after coronary artery bypass graft surgery. 30 32

The effect of dipyridamole (Persantine) on the thrombocyte count and bleeding tendency in connection with open-heart surgery and perfusion was studied in 22 patients. A control series of 21 patients undergoing open-heart surgery was available. The treatment group received dipyridamole, 0.5 mg. per kilogram of body weight, in the beginning of cardiopulmonary bypass into the heart-lung machine and thereafter 10 mg. intravenously three times daily for 2 days. From the third day dipyridamole was administered by mouth, 75 mg. three times a day, until the patient was discharged from hospital. We found that dipyridamole had the effect of maintaining the thrombocyte count during cardiopulmonary bypass and the first and second postoperative days. Thereafter no significant difference was seen between the dipyridamole and control groups. The use of dipyridamole did not increase the postoperative hemorrhagic tendency. There were no significant differences in per- and postoperative blood loss and in bleeding and activated partial thromboplastin times between the groups.
J Thorac Cardiovasc Surg 1977 Aug
PMID:The effect of dipyridamole on the thrombocyte count and bleeding tendency in open-heart surgery. 88 83

The essentially indefinite storage life of previously frozen erythrocytes (PFE), combined with the virtual freedom from hepatitis, high 2,3-diphosphoglycerate (2,3-DPG) content, and low level of HL-A antigens, should make its use in open-heart surgery attractive. However, since the suspension medium for PFE is usually saline, the potential exists for creating a hemorrhagic diathesis by accentuating the dilution of plasma procoagulants by the pump prime. To test this possibility, we used PFE exclusively in transfusing a group of 13 open-heart surgery patients; they were given no plasma or platelets. A control group of 12 open-heart surgery patients were transfused with only shelf blood. Determination of prothrombin times (PT), partial thromboplastin times (PTT), platelets, and fibrinogen were done at various intervals. No clinically significant differences between the two groups were seen in any of these parameters at any interval, and there was no significant difference between the groups in amount of chest tube drainage or transfusions in the first 24 hours. It is concluded that most open-heart surgery can be safely performed exclusively with frozen blood.
J Thorac Cardiovasc Surg 1975 Sep
PMID:The effect on blood coagulation of the exclusive use of transfusions of frozen red cells during and after cardiopulmonary bypass. 116 42

In order to investigate the safety of prolonged heparinless venoarterial bypass (HL-VAB), we subjected 18 sheep to prolonged HL-VAB for up to 6 days. Three animals died of granulomatous lung abscess and one died from intra-abdominal abscess. One animal died of generalized thromboembolism secondary to mechanical damage of the nonthrombogenic coating occurring at the time of cannulation. HL-VAB was successfully carried out in 13 sheep. Although clots were found at all tubing connections where blood turbulence occurred, only the previously mentioned animal showed evidence of thromboembolism. Damage to the nonthrombogenic tubing exposed to the roller pump head was seen in all animals, and its severity appeared to be related to the duration of bypass. Scanning electron microscopic examination revealed scattered platelet aggregates on the nonthrombogenic coated surfaces without clinical evidence of embolization. Hematocrit values, leukocyte counts, platelet counts, prothrombin time (PT), activated partial thromboplastin time (PTT), thrombin time (TT), plasma fibrinogen levels, and factor V and VIII levels remained unchanged, whereas free plasma hemoglobin levels rose slightly during 6 days of HL-VAB. HL-VAB for up to 6 days appears to have little adverse effect on blood cells and blood coagulation factors. For current clinical use, the nonthrombogenic coated tubing circuit should be changed every 48 hours because of time-related trauma to the coated tubing from the roller pump.
J Thorac Cardiovasc Surg 1976 May
PMID:Successful prolonged heparinless venoarterial bypass in sheep. 126 48

To facilitate perfusion rewarming without the use of total body heparinization or an oxygenator following open-heart correction with surface hypothermia, we divised a pump circuit. The circuit, totally primed with 100 c.c. of saline, consists of polyurethane-polyvinyl-graphite (PPG) coated Tygon tubes (with one end tapered by heat treatment) and a copper-coil heat exchanger. A roller pump was used to achieve partial bypass from the left atrium to the ascending aorta with flow rates up to 70 c.c. per kilogram per minute. Experiments in dogs resulted in rapid rewarming, immediate return of cardiac function, and hematologic alterations similar to those noted during surface rewarming. The safety of the method was also demonstrated. Prothrombin time, partial thromboplastin time, and platelet values returned to control levels upon rewarming, and no thromboemboli or bleeding problems were noted. Six clinical experiences were accumulated. Details of the method, hematologic and blood chemical analyses in dogs, and the first clinical trial in a 3-month-old infant with transposition of the great vessels are reported.
J Thorac Cardiovasc Surg 1976 May
PMID:Heparinless, oxygenatorless perfusion rewarming following surface-induced deep hypothermia for open-heart surgery. 126 65

A pre-operative coagulation profile was performed on 10 consecutive patients undergoing open-heart surgery. 16.3% of patients had at least one abnormal result. The most common abnormality was found in the partial thromboplastin time system. All patients were treated with replacement of appropriate specific blood products during surgery. These measures prevented significant excess blood loss in the study group as compared to a control group of patients, both at surgery and over a twenty-four hour post-operative period.
J Cardiovasc Surg (Torino)
PMID:Detection and treatment of pre-operative coagulation abnormalities in cardiac surgical patients. 127 May 7

Ten percent pentastarch is a low-molecular-weight hydroxyethyl starch with greater oncotic pressure and shorter intravascular persistence than 6% hetastarch. To evaluate its safety and efficacy as a component of cardiopulmonary bypass priming solution, we prospectively studied 90 patients undergoing coronary artery bypass grafting or valve replacement necessitating cardiopulmonary bypass (bubble oxygenator and moderate systemic hypothermia). Sixty patients were randomized to receive 75 gm of either 10% pentastarch (group P) or 25% albumin (group A), and 30 patients received lactated Ringer's solution alone (group C). Intravascular colloid osmotic pressure during cardiopulmonary bypass was highest with either of the colloid primes (15-minute measurement: group P, 15.7 +/- 2.2 mm Hg (mean +/- standard deviation); group A, 15.2 +/- 2.0 mm Hg; group C, 11.3 +/- 1.7 mm Hg; p less than 0.05, groups P and A compared with group C). This was associated with a lower volume requirement during cardiopulmonary bypass to maintain the venous reservoir (group P, 333 +/- 318 ml; group A, 483 +/- 472 ml; group C, 1332 +/- 1013 ml; p less than 0.05, groups P and A compared with group C). Urine output during cardiopulmonary bypass was similar in each group. Net intraoperative fluid balance was lowest in the colloid groups (groups P and A, 5.7 +/- 1.4 L; group C, 6.9 +/- 1.3 L; p less than 0.05, groups P and A compared with group C). Cardiac index shortly after weaning from cardiopulmonary bypass was greatest in group P (group P, 3.2 +/- 0.9; group A, 2.8 +/- 0.8; group C, 2.7 +/- 0.6 dyne.sec.cm-5; p less than 0.05, group P compared with group C). Changes in alveolar-arterial oxygen gradients, shunt fraction, and effective compliance were similar in all groups. During cardiopulmonary bypass, pentastarch appeared to cause the greatest degree of hemodilution, as suggested by the lowest hemoglobin, factor VII and IX levels and platelet count. The activated partial thromboplastin time was significantly prolonged during and immediately after cardiopulmonary bypass in group P relative to groups A and C (p less than 0.05), although there were no significant differences in the activated clotting time before cardiopulmonary bypass, during cardiopulmonary bypass, or after heparin neutralization. As well, clinical indices of hemostasis, including mediastinal drainage, red cell, platelet, and fresh frozen plasma requirements, and reoperation for excessive postoperative bleeding, were similar. We conclude that pentastarch, when used in cardiopulmonary bypass prime, is as safe as either albumin or Ringer's solution alone.(ABSTRACT TRUNCATED AT 400 WORDS)
J Thorac Cardiovasc Surg 1992 Aug
PMID:The safety and efficacy of ten percent pentastarch as a cardiopulmonary bypass priming solution. A randomized clinical trial. 137 60

This study aimed to determine the kinetics of albumin resorption from and the healing of two types of albumin impregnated Vasculour II (Bard Cardiovascular) Dacron grafts (ACG-A and ACG-B) using whole blood preclotted Vasculour II Dacron grafts (without albumin) as controls (PCC). Prostheses measuring 4 mm ID x 50 mm length were implanted in the aortoiliac position in 24 dogs (ACG-A n = 12, ACG-B n = 24, PCC n = 12) and explanted after 1, 2 4, and 6 months. Platelet count, platelet aggregometry to 10(-5) M ADP, prothrombin time (PT), and partial thromboplastin time (PTT) were determined preoperatively and at explantation. Sections of the explanted grafts were assayed for human albumin by immunohistochemical techniques utilizing a rabbit polyclonal mono-specific antibody for human albumin followed by the addition of a biotinylated goat anti-rabbit IgG. Immunoperoxidase staining was then performed using Avidin D horse-radish peroxidase. Histology of the grafts (light microscopy, scanning electron microscopy, and transmission electron microscopy) as well as percent thrombus free surface area (TFSA) by computerized planimetry were also determined. Seven of 48 grafts were occluded (85.4% patency) with no difference among the three groups. Platelet aggregometry was not predictive of graft patency. No change in PT or PTT occurred nor was there any difference among the three groups. Retained albumin was detected in every one-month explant but not beyond that time, with the sensitivity for detecting human albumin in this assay being 20 mg albumin per gram of Dacron. All ACG explants at one month revealed inner capsular fibrin coagula not present in PCC specimens.(ABSTRACT TRUNCATED AT 250 WORDS)
J Cardiovasc Surg (Torino)
PMID:Albumin impregnated vascular grafts: albumin resorption and tissue reactions. 138 74

The accurate assessment of coagulation status is an important part of interventional procedures performed in the cardiac catheterization laboratory. While the traditional clinical means of assessing heparin anticoagulation has been with the activated partial thromboplastin time (APTT), the activated coagulation time (ACT) has come into widespread use in the catheterization laboratory as an assay of whole blood clotting time which can be performed rapidly at the bedside. The purpose of the present study was to (1) assess the anticoagulant effect of a 10,000 U bolus of heparin in PTCA patients and (2) document the relationship between ACTs and APTTs in a subset of these patients. Baseline and postheparin ACTs were measured using a HemoTec coagulation timer in 545 unselected PTCA patients. The average baseline ACT was 120 +/- 22 sec. After a 10,000 U bolus of heparin the average ACT was 249 +/- 44 sec; 58% of patients had an ACT less than 250 sec, 17% had an ACT between 250 and 275 sec, 12% had an ACT between 275 and 300 sec, and 13% had an ACT greater than 300 sec. A total of 175 paired ACT and APTT measurements were obtained in a random subset of these patients at baseline, after heparinization, and at 4-6 hr intervals after the procedure. The APTT was limited by absolute upper and lower limits of 150 and 22 sec; there were no such limits on the ACT. When limiting values were excluded, there was a strong overall correlation between ACT and APTT measurements (r = 0.92, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
Cathet Cardiovasc Diagn 1992 Aug
PMID:Activated clotting times and activated partial thromboplastin times in patients undergoing coronary angioplasty who receive bolus doses of heparin. 844 6


1 2 3 4 5 6 7 8 9 10 Next >>