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Biomedical subjects

C R Prentice

Publications and source records attributed to C R Prentice.

At least 91 records · Page 5Linked to original sources
PubMed1982

Beta-thromboglobulin and platelet counts - effect of malignancy, infection, age and obesity.

Plasma levels of beta-thromboglobulin (BTG) and platelet count were studied in 69 control subjects, 19 patients with operable abdominal malignancy, and 9 patients with acute bacterial infection. In control subjects there was a significant rise in BTG and fall in platelet count with age, and a negative correlation of BTG with obesity. BTG and platelet count were normal in patients with operable malignancy, but significantly increased in patients with acute bacterial infection. These effects must be considered in studies of BTG and thrombosis.

Adult↗
PubMed1982

Increased blood viscosity and fibrinolytic inhibitor in type II hyperlipoproteinaemia.

Blood rheology and several haemostatic factors were studied in patients with type II hyperlipoproteinaemia (HLP) and matched controls. HLP patients had increased blood viscosity (p less than 0.01), the mean level being 18% higher at a low shear-rate (0.94 s-1) and 13% higher at a high shear-rate (94 s-1). The increased viscosity was due partly to a raised haematocrit (p less than 0.05), and partly to increased plasma viscosity (p less than 0.01) associated with increased plasma fibrinogen (p less than 0.02). Red cell deformability was normal, and viscosity was unrelated to either lipid or lipoprotein concentrations. Levels of the major fibrinolytic inhibitor. alpha 2-antiplasmin, measured by both functional and immunological techniques were higher in HLP patients (mean increase 30-32%). Plasminogen activator levels were normal in HLP patients and the ratio of fibrinolytic inhibitor to activator was therefore increased. Plasminogen concentrations were also increased. Levels of factor VIII activity and antigen, antithrombin III and anti-factor Xa activity, alpha 2-macroglobulin, platelet count, and platelet aggregation by adenosine diphosphate and adrenaline did not differ significantly in HLP patients and controls. These results suggest that the premature arterial disease associated with HLP may be related to increased blood viscosity, which reduces arterial blood flow, and increased alpha 2-antiplasmin, the major inhibitor of fibrinolysis.

Adolescent↗
PubMed1982

Plasma fibrinopeptide A and beta-thromboglobulin in pre-eclampsia and pregnancy hypertension.

Increased plasma levels of beta-thromboglobulin (beta TG) and fibrinopeptide A (FPA), markers of platelet release and thrombin generation respectively, were measured in normal women, women taking oral contraceptives, normal pregnancy and pregnant women with hypertension or pre-eclampsia. No significant increases in beta TG or FPA were found in women taking oral contraceptives. Significantly increased concentrations of beta TG, but not FPA, were found in normal pregnant women in the second and third trimester of pregnancy when compared with non-pregnant age-matched controls. In eleven women with pregnancy hypertension and thirteen women with pre-eclampsia significantly elevated levels of both beta TG and FPA were found when compared with age, parity and gestation-matched pregnant controls. Although the mean value for both beta TG and FPA in the group with pre-eclampsia was higher than the group with pregnancy hypertension, the difference was not statistically significant. These findings provide additional evidence that pre-eclampsia and pregnancy hypertension are associated with activation of the coagulation system and the platelet release reaction.

Beta-Globulins↗
PubMed1982

Prediction and selective prophylaxis of venous thrombosis in elective gastrointestinal surgery.

Clinical features were noted and routine and non-routine laboratory variables were measured before elective major gastrointestinal surgery in 63 patients aged 40 years or more. Deep-vein thrombosis (DVT), detected by routine 125I-fibrinogen leg scanning, developed in 21 patients. Five clinical variables but no laboratory variables were significantly associated with DVT: age; percent mean weight for age, sex, and height (%MW); presence of varicose veins; cigarette-smoking; and sex. The most useful discriminant index of these variables was age in years plus 1.3 x %MW. The index was validated prospectively in a further 41 patients, in 18 of whom DVT developed. The value of the index in selective prophylaxis was then assessed in a further 40 patients, of whom 24 (60%) with high-risk index received low-dose heparin (5000 units twice daily). DVT developed in 4 of the 40 patients, an incidence of 10% compared with the incidence of 37.5% (39 of 104) in the earlier studies with no prophylaxis.

Adult↗
PubMed1982

Effects of the non-selective beta-adrenoceptor blocking agent, carteolol, on platelet function, blood coagulation and viscosity.

We have studied the effect of a new beta-adrenergic blocker, carteolol, on platelet function, blood coagulation and viscosity in 10 healthy male volunteers. Following carteolol (5 mg orally) we were able to demonstrate significant inhibition of platelet aggregation to ADP (p less than 0.05) and adrenaline (p less than 0.01) after 5 hours, but not at 2 or 24 hours. This maximum inhibition of platelet aggregation corresponded to peak plasma concentrations of carteolol measured. The platelet release reaction, as measured by plasma levels of the platelet specific protein beta-thromboglobulin (BTG) was unaltered and there was no significant effect on a panel of coagulation tests or on blood viscosity.

Adenosine Diphosphate↗
PubMed1982

Endotoxemia, disturbance of coagulation, and obstructive jaundice.

A prospective study of coagulation disturbances and endotoxemia in 42 patients having major pancreatic or biliary surgery was performed. Endotoxin, soluble fibrin, and fibrin degradation products were measured before and after operation in 28 patients with obstructive jaundice and in 14 nonjaundiced controls. In the control group there was one death and no unexplained fever or postoperative hemorrhage. The jaundiced group had more complications: seven deaths, nine episodes of fever, and six episodes of hemorrhage. Soluble fibrin was detected only in patients with obstructive jaundice, in whom it occurred in 38 percent before operation. Positive endotoxin assay was as common in control patients as in the jaundiced group, but in the latter endotoxin was associated (p less than 0.05) with increased FDP and soluble fibrin. Patients with endotoxin or increased FDP levels before operation for jaundice carry a poor prognosis (7 of 11 died). Preoperative bowel preparation in 16 of the jaundiced patients did not affect the outcome.

Adult↗
PubMed1982

Double-blind controlled clinical trial of ancrod for ischemic rest pain of the leg.

In a randomized double-blind trial, patients with ischemic rest pain of the leg received 8 days of treatment with intravenous injections of the defibrinating agent, ancrod (Arvin) or saline. Plasma fibrinogen, plasma viscosity, and blood viscosity were significantly reduced during ancrod therapy. After 27 patients had completed treatment, sequential analysis showed no preference for either therapy. In each group two-thirds of the patients claimed improvement in pain after treatment. There were no significant differences between treatment groups in analgesic consumption, Doppler systolic pressure ratio, or surgical intervention in the 6 months following treatment. We conclude that in patients with ischemic rest pain, ancrod therapy is not superior to placebo injections, and that the effect of placebo treatment is considerable.

Aged↗
PubMed1981

Successful treatment of Raynaud's Syndrome with prostacyclin.

There is evidence to suggest that platelet activation occurs in Raynaud's syndrome. We evaluated the effect of prostacyclin (PGI2) a potent antiplatelet and vasodilator agent in 5 female patients with Raynaud's syndrome. Outpatient visits were made at weekly intervals for 4 weeks. At the first visit buffer solution (Wellcome Laboratories) was infused intravenously for 5 hrs, thereafter three five hr infusions of PGI2 at a peak dose of 10 ng/Kg/min were given. Six weeks after the infusions patients were reviewed. Symptomatic improvement, including healing of ischaemic ulcers, occurred in 4 out of 5 patients. Thermography confirmed an increase in hand temperature after PCI2. Subjective and objective improvement has persisted for at least 6 weeks after the last treatment.

Ambulatory Care↗
PubMed1981

Prevention of deep vein thrombosis in medical patients by low-dose heparin.

A randomised trial was undertaken in one hundred patients with heart failure and/or chest infection to determine whether low-dose subcutaneous heparin induced the frequency of deep vein thrombosis (DVT) in the legs. Heparin, (5000 units 8 hourly) significantly reduced the frequency of DVT, diagnosed by the 125I-fibrinogen scan technique, from 26 to 4 per cent (p less than 0.01). Heparin was started within 12 hours of admission to hospital and continued until the patient was fully mobile. Heparin did not cause bleeding problems except for a 20 per cent incidence of injection site bruising. We therefore recommend prophylaxis with low-dose subcutaneous heparin in patients with heart failure or chest infection who require more than three days bed rest.

Aged↗
PubMed1980

Relation between extent of coronary artery disease and blood viscosity.

Blood viscosity (shear rate 100/s) and its major determinants (packed cell volume, plasma fibrinogen concentration, and plasma viscosity) were measured before coronary angiography in 50 men aged 30-55 and related to the extent of coronary artery disease. Twenty-six men had extensive disease (stenosis of two or three major coronary vessels), and 24 had either stenosis of one vessel or no stenosis. The 26 men with extensive disease had significantly higher mean blood viscosity than those with mild or no disease and 25 healthy controls (p less than 0.001). The increased viscosity was due partly to a higher packed cell volume and partly to a higher fibrinogen concentration; plasma viscosity was not significantly increased. These differences could not be explained by smoking history. These results suggest an association between increased blood viscosity and extensive coronary artery disease in men, which merits further investigation.

Adult↗
PubMed1980

Comparison of Pasteur and Behringwerke antivenoms in envenoming by the carpet viper (Echis carinatus).

Bites and envenoming by the carpet viper Echis carinatus are common medical emergencies in parts of Nigeria, but the most effective use of the various commercially produced antivenoms in treatment has not been established. Pasteur Paris Echis monospecific and Behringwerke West and North Africa Bitis-Echis-Naja polyspecific antivenoms were compared in two groups of seven patients with incoagulable blood after E carinatus bites. In both groups spontaneous bleeding stopped within a few hours and local swelling subsided within two weeks after the initial antivenom injection. Pasteur antivenom (20-40 ml) restored blood coagulability within 12 hours in all cases, but 60--180 ml of Behringwerke antivenom was effective in only four cases. Persisting venom procoagulant activity was observed in the remaining three cases. Despite its potency in the mouse protection test, Behringwerke antivenom is unreliable and unpredictable in neutralising venom procoagulant in humans bitten by E carinatus.

Adult↗
PubMed1980

Low dose heparin in the prevention of deep-vein thrombosis after aortic bifurcation graft surgery.

In a randomised double-blind controlled trial 24 patients undergoing elective aortic bifurcation graft surgery received subcutaneous calcium heparin (2,500 u pre-operatively then 5,000 u 12-hourly for 7 days) and 25 control patients received saline injections. All patients received a routine dose of intravenous sodium heparin intra-operatively. The trial was terminated because of excess bleeding complications in patients receiving subcutaneous heparin (8 vs. 1, p less than 0.05). Deep vein thrombosis occurred in 6 control patients and 2 patients on heparin (p less than 0.05). In this group of patients undergoing major vascular surgery the risk of bleeding due to heparin outweighed the potential benefit of thrombotic prophylaxis.

Aorta↗
PubMed1980

Increased plasma fibrinogen and platelet-aggregates in type II hyperlipoproteinaemia.

Plasma fibrinogen and platelet-aggregates (method of Wu and Hoak) were measured in 21 patients with familial Type II hyperlipoproteinemia and 21 matched control subjects. Patients with hyperlipoproteinaemia had increased levels of fibrinogen and platelet-aggregates (p less than 0.01). Young patients with hyperlipoproteinaemia had prematurely high fibrinogen levels, and the normal rise in fibrinogen during adult life was abolished. There were no statistically significant correlations within the patient group between fibrinogen, platelet-aggregates, and plasma lipids. High fibrinogen and platelet-aggregate levels may play a part in the development of the premature arterial disease associated with Type II hyperlipoproteinaemia, or may be markers of arterial injury.

Adolescent↗