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Biomedical subjects

A Aronstam

Publications and source records attributed to A Aronstam.

At least 37 records · Page 2Linked to original sources
PubMed1982

Effect of height and weight on the in vivo recovery of transfused factor VIII C.

The in vivo recovery of factor VIII has been estimated on 84 occasions in 53 severely affected adolescent haemophiliacs. There was wide individual variation in recovery, which was not affected by differences in the administered dose. Recovery increased steadily with increasing surface area, and it was only over a surface area of 1.7 m2 that a recovery of 2% of factor VIII per unit per kg became the norm. It is suggested that the only safe assumption to make below that surface area in an in vivo recovery of 1.5%.

Adolescent↗
PubMed1982

Anticoagulant antibodies in the synovial membranes of patients suffering from haemophilia, rheumatoid arthritis and other rheumatic disorders.

This study has identified IgG and IgM anticoagulant antibodies in the synovial membranes of patients suffering from haemophilia and rheumatoid arthritis (RA) but not in synovial tissues from normal subjects or in patients with other arthritides. In the majority of cases the antibody appeared to have the specificity of the lupus-like anticoagulant (LLA) seen in patients with systemic lupus erythematosus (SLE). The importance of these findings with regard to the treatment of certain cases of haemophilia and RA and the possible relation between the presence of these antibodies and viral infections is discussed.

Antibodies↗
PubMed1982

A comparative trial of a controlled-release iron tablet preparation ('Ferrocontin' Continus) and ferrous fumarate tablets.

A single-blind, crossover comparative study was carried out in 40 patients with iron deficiency anaemia to assess the clinical efficacy and tolerance of once daily treatment with a controlled-release preparation of ferrous glycine sulphate ('Ferrocontin' Continus) and ferrous fumarate. Patients were allocated at random to receive 1 tablet (equivalent to 100 mg elemental iron) daily of one or other preparation for 4 weeks and were then crossed over to the alternative preparation for a further 4 weeks. The results showed that the significant increases in haemoglobin, packed cell volume and mean corpuscular volume were similar with both preparations. Seventeen patients reported gastro-intestinal side-effects on one or both preparations and the incidence was slightly less in patients whilst receiving the ferrous glycine sulphate preparation. In 3 patients, side-effects were sufficiently severe whilst taking ferrous fumarate to warrant interruption of treatment in 2 and withdrawal from the study in the other.

Adult↗
PubMed1981

A radial immunodiffusion method for the assay of factor VIII:C Antigen (VIII:C Ag) in plasma.

A method has been developed for the immunological quantitation of factor VIII:C Ag using a medium titre (50 new Oxford units) factor VIII:C antibody arising in a severe multitransfused haemophiliac. The method, which utilizes clotting inhibition in an agarose gel medium, gave close and significant correlation with the two-stage factor VIII:C procoagulant assay (r=0.83, P less than 0.01) for 54 normal subjects. Similar or higher values were found in 19 mild, moderate and severe haemophiliacs with 2-30% average normal plasma levels of factor VIII:C (r=0.72, P less than 0.01). Four mild von Willebrand patients gave similar results by immunoassay and procoagulant assay methods. A previously identified patient with cross reacting material (CRM+) gave an immunoassay within the normal range (66%) with only 4% VIII:C activity detectable. The method offers a simple, sensitive and apparently reliable procedure for the assay of plasma factor VIII:C Ag which may prove useful in the further investigation of factor VIII:C Ag and antibody heterogeneity. The procedure offers an alternative to immunoradiometric assay and may be of potential use in the assessment of the haemophilia carrier state and possibly the early detection of thrombosis.

Antigens↗
PubMed1981

The effect of bleeding patterns on the response of haemophilic haemarthroses to different doses of factor VIII.

Three hundred and thirty-nine consecutive bleeds into the knees, elbows and ankles of severe haemophiliacs were graded I if more than 50% of normal movement was present, and graded 2 if less than 50% of normal movement was present. Nursing staff then administered randomly allocated doses of 7,14 or 28 units of factor VIII per kg. Medical staff unaware of initial doses assessed progress thereafter at 12-hourly intervals. Grade I bleeds into "normal" joints showed no difference in response to the three dosage regimes, but grade 2 bleeds did worse on low doses. There was no significant difference in the response to each dose of bleeds into restricted and into target joints. However, when a restricted joint became a target joint as well, both grade I and grade 2 bleeds did badly on low doses. The target joint as well, both grade I and grade 2 bleeds did badly on low doses. The percentage of patients with bleeds into these joints whose range of movement had not returned to baseline 48 h after receiving a low dose of factor VIII was significantly higher than those who had received the higher doses.

Ankle Joint↗
PubMed1980

Double-blind controlled trial of three dosage regimens in treatment of haemarthroses in haemophilia A.

A double-blind controlled trial comparing doses of 7, 14, and 28 units/kg of factor VIII for knee, ankle, and elbow haemarthroses was carried out on a group of severe haemophiliacs. Mild-to-moderate ankle bleeds responded as well to 7 units/kg as to higher doses. All grades of knee bleeds fared worse when subjected to the lowest dose. Mild elbow bleeds responded to the lowest dose, but moderate elbow bleeds required higher doses.

Adolescent↗
PubMed1980

Comparison of three methods for the estimation of plasma antithrombin.

Plasma antithrombin levels were measured by clotting, immunological, and amidolytic methods on two groups of subjects: 20 normal individuals and nine patients studied serially post-operatively (hip replacement). The postoperative patients were observed for the emergence of deep-vein thrombosis using 125I-fibrinogen uptake measurements (FUT). The three methods gave similar ranges for the normal subjects, were reproducible (cv less than 5%), and detected early postoperative reduction of antithrombin levels. All three methods failed to show any significant differences in preoperative antithrombin levels between the positive and negative FUT groups. Correlation studies were performed on the pooled data from the normal and postoperative group (range 60-130% of normal; 100 samples). The best correlation (r = 0.75; P less than 0.01) was achieved with the chromogenic kit assay method versus the Mancini immunoassay technique. The thrombin agarose (total antithrombin) gel diffusion technique correlated less well with the chromogenic (r = 0.65; P less than 0.01) and Mancini immunoassay (r = 0.45; P less than 0.01) methods. It is concluded that the chromogenic kit method gives a rapid, reproducible, and specific measurement of antithrombin III. The thrombin agarose diffusion method, though not specific for antithrombin III, is a cheap and simple method to perform. The potential of the three methods for detecting the prethrombotic stage and early thrombosis is discussed.

Adolescent↗
PubMed1979

The frequency of bleeding and height of adolescent haemophiliacs.

The relation between the height of adolescent haemophiliacs and their bleeding frequency has been studied. 45 haemophiliacs aged 10--19 years were divided into 3 groups: small, medium and tall, using a Height Standard Deviation Score. The average bleeding frequency per 100 days in the group of small haemophiliacs was 8.71 +/- SD 4.47, in the medium height group 10.18 +/- SD 6.71, while the tall individuals bled in average 15.97 +/- SD 3.15 every 100 days. There was no relationship between age and bleeding frequency.

Adolescent↗
PubMed1979

Patterns of bleeding in adolescents with severe haemophilia A.

Eighty-two boys with severe haemophilia A who spent some time at Lord Mayor Treloar College during 1973-7 were studied. All episodes of bleeding that occurred during term time were recorded, along with the number of transfusions. The bleeding frequency among these boys, most of them aged 10-17 years, increased steadily from 8,31 episodes/100 days in 1973 to 12,63 episodes/100 days in 1977. At the same time there was a steady fall in bleeding frequency with age. Altogether 24% of bleeding episodes were into the elbow joint, 22% into the knee, and 15% into the ankle. As the boys grew older the proportion of bleeding episodes in the legs declined and that in the arms increased. The overall results reflect the fact that special schools now see only the severest cases of haemophilia. The pattern of bleeding during adolescence suggests that concepts of management of arm bleeding need modifying.

Adolescent↗
PubMed1979

Multiple bleeds in haemophilia A.

One hundred and eighty-one bleeding episodes involving two sites simultaneously were noted during a survey of 4935 bleeding episodes, an incidence of 3.7%. Elbows, knees and ankles were the commonest sites involved in double bleeds, while the thigh, upper arm and elbow were the commonest sites involved in the double bleeds needing most transfusions. The overall transfusion requirements were less than for single bleeds. The frequency of multiple bleeds correlated significantly with the overall bleeding frequency, but not with the number of days under observation.

Ankle↗
PubMed1979

Transfusion requirements of adolescents with severe haemophilia A.

The transfusion requirements of 75 adolescents with severe haemophilia A were studied during the five-year period 1973-77. The annual incidence of the 4935 episodes studied increased by a factor of 2.2 while the number of transfusions rose by a factor of 2.5 and the amount of therapeutic material used during the five years of the survey increased by a factor of 2.6. A further 166 bleeds occurred during periods of prophylaxis in 1976 and 1977, which generated a 25% increase in factor VIII used during those years. The increased usage of factor VIII in the years 1976 and 1977 was thus due mainly to increased numbers of transfusions given per bleed and to the use of prophylaxis but also to a slight increase in the units of factor VIII given in each dose. Twice weekly prophylaxis reduced the bleeding frequency by 30% and resulted in an increase of about 12% in usage of factor VIII. Prophylaxis given three times weekly reduced the bleeding frequency by about 60% at the cost of an increase of 77% in therapeutic materials. Iliopsoas, retroperitoneal, and abdominal wall bleeds were the commonest bleeds needing retransfusion within 24 hours, while bleeds into the extremities of the upper and lower limbs needed least retransfusions within 24 hours. Retroperitoneal bleeds needed the most transfusions per episode followed by iliopsoas, buttock, abdominal wall, and hip joint bleeds. The transfusion requirements of bleeds below the diaphragm tended to diminish steadily the more peripheral they became. This relationship did not hold for upper limb bleeds.

Adolescent↗
PubMed1978

Heparin neutralizing activity in patients with renal disease on maintenance haemodialysis.

Heparin neutralizing activity (HNA) was increased in plasma of patients with end-stage renal disease treated by maintenance haemodialysis. It was not raised in non-dialyzed patients with chronic renal failure, nor in patients with normal renal function who had been exposed to the extracorporeal circulation of the heart-lung bypass 48--72 hr before testing. It is postulated that the trauma of extracorporeal circulation causes platelets to release HNA which is not cleared by the dialysis membranes of the artificial kidney but is by the human kidney. This may have therapeutic implications for heparin dosage schedules during haemodialysis.

Coronary Artery Bypass↗
PubMed1978

Ristocetin and the thrombin clotting time.

The addition of the antibiotic ristocetin to plasma accelerated the thrombin clotting time (TCT) in 20 out of 22 subjects. Prior incubation of ristocetin with thrombin or plasma did not alter its effect on the TCT. Ristocetin accelerated clotting greatly at low but not at high levels of thrombin. A simple linear correlation between heparin concentrations and the TCT was demonstrated when ristocetin at 2.5 mg per ml was added to plasma containing between 0.05 and 0.5 unit of heparin per ml. There are implications for assay procedures involving heparin and the TCT.

Blood Coagulation Tests↗
PubMed1977

Twice weekly prophylactic therapy in haemophilia A.

Factor VIII-containing materials were administered to four severely affected haemophiliacs twice weekly in doses calculated to raise the factor VIII level to either 15% or 30% of average normal. The pooled results from those patients with statistically similar baseline bleeding frequencies showed a significant reduction in bleeding frequency on both doses in the first 48 hours. The 30% dose produced a more significant reduction than the 15% dose in the first 24 hours, but there was no significant difference between the two doses in the second 24 hours. It appears that to reduce the bleeding frequency of severely affected haemophiliacs by 60% would require a two-and-a-half-fold increase in therapeutic materials. A 90% reduction would need nine times the amount of material currently in use.

Child↗