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Biomedical subjects

C D Forbes

Publications and source records attributed to C D Forbes.

At least 217 records · Page 12Linked to original sources
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↗
PubMed1982

To tell or not to tell: haemophiliacs' views on their employment prospects.

As part of a study on the employment situation of haemophiliacs carried out by four Haemophilia Centres in the United Kingdom, the patients were invited to express their own views on their employment problems and prospects. 225 patients, most of them severely or moderately affected by the disease, made comments which were classified into eight categories. The results show that one third of the patients were preoccupied with whether or not to tell the employer about their condition. The ignorance of employers about haemophilia and of the benefits of self-treatment was also emphasised by many patients. It appears that education of both potential employers and of the public is essential for the rehabilitation of, and the provision of, satisfactory working conditions for the haemophiliac.

Adolescent↗
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

Increased blood viscosity in young women using oral contraceptives.

Blood viscosity and its major determinants (hematocrit, plasma fibrinogen, and plasma viscosity) were measured in 25 men, 25 women who were not using oral contraceptives, and 25 women who had been using oral contraceptives for at least 3 months. Mean blood viscosity and hematocrit were significantly higher in women using oral contraceptives than in women who were not (p < 0.001), and use of oral contraceptives abolished the normal sex difference in blood viscosity and hematocrit. After correction to a standard hematocrit of 45%, blood viscosity was still higher in users or oral contraceptives, as was plasma fibrinogen (p < 0.05). Plasma viscosity was not significantly increased in users of oral contraceptives.

Adolescent↗
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

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↗
PubMed1980

Blood viscosity in young male diabetics with and without retinopathy.

Blood viscosity (shear rates 100s-1 and 0.94s-1) and several of its major determinants (haematocrit, plasma fibrinogen and plasma viscosity) have been measured in 38 male insulin-treated diabetics, aged 18-50 years, and in 38 non-diabetic control subjects matched for age and smoking habit. Diabetics without fundoscopic retinopathy (n=20) had higher mean blood viscosity than controls at the high shear rate (7.07 cP vs 6.75 cP, p < 0.05) and the low shear rate (21.2 cP vs 18.7 cP, p < 0.025). These differences persisted after correction of blood viscosity to a standard haematocrit, and were associated with increased plasma viscosity (1.41 cP vs 1.34 cP, p < 0.025) and plasma fibrinogen (2.9 g/L vs. 2.5 g/L, p < 0.025). Diabetics with retinopathy (n = 18) had higher mean blood viscosity than diabetics without retinopathy at the high shear rate (7.53 cP vs 7.07 cP, p < 0.05) and the low shear rate (24.3 cP vs. 21.2 cP, p < 0.05), associated with a higher haematocrit (p < 0.05). Blood viscosity and haematocrit correlated with the duration of diabetes (r > 0.32, p < 0.05).

Adolescent↗
PubMed1980

An assessment of red cell deformability using a simple filtration method.

We assessed the simple method of measuring red cell deformability described by Reid et al. The technique was found to be reproducible. The validity of the method as a measure of red cell deformation was confirmed by (a) marked reduction of the deformability index after fixation of red cells with glutaraldehyde, and (b) an inverse correlation of deformability index with high-shear blood viscosity (r = 0.4; P < 0.001). There was no correlation of deformability index with low-shear blood viscosity, plasma viscosity, fibrinogen, or the white cell count. In normal subjects, deformability index was similar in males and females, and in smokers and non-smokers. Patients with acute myocardial infarction, or intermittent claudication, had reduced deformability compared to controls (P < 0.01).

Blood Viscosity↗
PubMed1980

The effects of age and cigarette-smoking on blood and plasma viscosity in men.

We measured blood viscosity and its major determinants (haematocrit, plasma fibrinogen and plasma viscosity) in 90 apparently healthy men aged 16 to 80 years. Cigarette-smokers (n = 45) had higher levels of blood viscosity, haematocrit and fibrinogen (p less than 0.001) and plasma viscosity (p less than 0.025) than non-smokers (n = 45). Blood viscosity was still higher in smokers after correction to a standard haematocrit (p less than 0.02). Fibrinogen, corrected blood viscosity and plasma viscosity rose with age in both groups, but young smokers had prematurely elevated levels of these variables and less pronounced rises with age. These results show that age and cigarette-smoking must be considered in studies of blood and plasma viscosity, and provide further evidence for an association between viscosity and arterial disease.

Adolescent↗