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Biomedical subjects

J D Cash

Publications and source records attributed to J D Cash.

At least 55 records · Page 3Linked to original sources
PubMed1977

Plasma beta-thromboglobulin in diabetes mellitus.

The plasma beta-thromboglobulin (betaTG) content was measured in 56 diabetic patients with known complications of this disease, including neuropathy, retinopathy, and ischemic skin lesions. Although two patients were found to have elevated levels beyond the normal range, there was no significant difference between the diabetic group as a whole and the group of 35 controls. The significance of these findings with regard to the proposed contribution of small-vessel platelet sequestration in the pathogenesis of late complications of diabetes mellitus is discussed.

Beta-Globulins↗
PubMed1976

Haemophilia A and the blood transfusion service: a Scottish study.

The demand for blood products containing factor VIII for treating patients with haemophilia A in south-east Scotland was reviewed. From 1961 to 1975 the demand for fresh frozen plasma (FFP), cryoprecipitate (CP), and antihaemophilic factor (AHF) increased by seven and a half times, while total donations increased by only a third. Patients with severe haemophilia A treated at the regional haemophilia centre used about 85% of the factor VIII issued in 1971-4, most of which was used on demand. A patient with severe haemophilia A on unlimited ondemand home treatment would need about 500 units of factor VII/kg body weight/year, and a regional haemophilia centre, treating moderate and mild cases as well as severe ones, would use 15000 units/patient/year. Altogether about 50 million units of factor VIII will be needed each year in the UK. Although cryoprecipitate is much harder to store and administer than AHF, its yield from plasma may be far greater and its cost far smaller. Unless the blood transfusion services receive increased amounts of money and reappraise their functions and operation, it seems likely that they will have to rely increasingly on commercial (and costly) sources for the major plasma fractions.

Blood Donors↗
PubMed1976

Three approaches to the radioimmunoassay of human beta-thromboglobulin.

Three radioimmunoassays for the measurement of beta-thromboglobulin are described. The standard method, using antiserum in solution, could be used to measure plasma concentrations of beta-thromboglobulin with the results available after 2-3 d. The use of a greater dilution of antiserum and tracer, with delayed addition of tracer, resulted in a more sensitive assay suitable for measuring b-thromboglobulin in urine. The use of a solid-couples antiserum under non-equilibrium conditions allowed the measurement of plasma levels of beta-thromboglobulin after an assay incubation time of 1 h. These three radioimmunoassay systems for beta-thromboglobulin cover the likely clinical requirements for the measurement of this platelet specific protein.

Beta-Globulins↗
PubMed1976

Studies on liberation of beta-thromboglobulin from human platelets in vitro.

A platelet specific protein, beta-thromboglobulin, is liberated during the preparation of platelet poor plasma. Using combinations of different anticoagulant and anti-platelet compounds, this release can be significantly reduced. The best results were obtained when native blood was collected as soon as possible into a mixture of EDTA, prostaglandin E1 and theophylline and maintained and processed at a temperature between 0 and 4 degrees C. These technical innovations have permitted the use of a radioimmunoassay for beta-thromboglobulin on plasma samples in clinical practice.

Anticoagulants↗
PubMed1975

Maternal serum FDP and circulating fetal red cells throughout pregnancy. A longitudinal study.

The presence of fetal red cells in the maternal circulation and the serum FDP content of 73 women was followed serially throughout a normal pregnancy. There was a signigicant increase in the mean serum FDP levels in late pregnancy, which was due to episodic elevations occurring in approximately 65% of women. These transient elevations appeared to increase in frequency and severity as pregnancy progressed. There was also an increase in the number of occasions fetal red cells were detected in the maternal circulation in the later months of pregnancy, but his phenomenon did not appear to be associated in any way to the serum FDP elevations. It is concluded that the episodic rises in serum FDP occurring in normal pregnancy are not related to episodes of occult disseminated intravascular coagulation secondary to placental haemorrhage as was previously hypothesized. Their etiology and clinical significance remain unknown.

Adolescent↗
PubMed1975

New rapid method for diagnosis of deep venous thrombosis.

The plasma concentration of the platelet-specific protein beta-thromboglobulin was measured in fourteen patients who had been investigated for deep venous thrombosis by venography or 125I-fibrinogen scanning. All six patients with a proven thrombus had a raised plasma concentration of beta-thromboglobulin. Eight patients in whom no thrombus could be demonstrated had plasma concentrations of beta-thromboglobulin similar to a control group of thirty-five normal individuals. These results indicate that the measurement of plasma beta-thromboglobulin concentrations may be of use in the diagnosis of deep venous thrombosis.

Adult↗
PubMed1975

Further investigations on antithrombin III in the plasmas of patients with the abnormality of antithrombin III Budapest.

Antithrombin III (AT-III) was studied in a thrombophilic family with an abnormal AT-III molecule (antithrombin III Budapest) using a modified crossed immunoelectrophoresis technique, gel filtration, 'rocket' immunoelectrophoresis and a heparin cofactor assay. When agarose was applied in the first phase of the crossed immunoelectrophoresis, the normal and the pathological AT-III revealed identical electrophoretic mobility. However, when heparin was mixed with agarose in the first phase of electrophoresis, the propositus' plasma displayed a different AT-III pattern from normal plasma. His plasma contained the first component of the normal plasma (Immune Antithrombin III1, IAT-III) in a concentration of only 5% of normal, and a protein in high concentration which although immunoreactive to AT-III antisera, had an electrophoretic mobility similar (but not identical to that of IAT-III2. This abnormal protein had no heparin cofactor activity and a molecular size greater than normal plasma AT-III. Unlike AT-III, the addition of heparin did not change the molecular size of the pathogic AT-III molecule significantly. The abnormal protein was present in lower concentrations in the patient's children and at the time of study they had no clinical or laboratory evidence of intravascular coagulation.

Adult↗
PubMed1975

The isolation and characterisation of a platelet-specific beta-globulin (beta-thromboglobulin) and the detection of antiurokinase and antiplasmin released from thrombin-aggregated washed human platelets.

A protein fraction was isolated from the supernatant of thrombin-aggregated washed human platelets and was shown, by immunodiffusion techniques, to contain a platelet-specific beta-globulin (beta-thromboglobulin) as the major component. A molecular weight of 35 800 was determined for beta-thromboglobin from the measured sedimentation coefficient of3.0 S and Stokes radius of 2.85 nm. Beta-Thromboglobin was detected in the serum from whole blood and the supernatant of 48-h-old platelet-rich plasma and 28-day-old citrated whole blood, but not in platelet-poor plasma. The fraction containing beta-thromboglobulin was shown to possess an antiurokinase activity but was devoid of antiplasmin activity. A further fraction of approximate molecular weight 70 000 was also isolated which contained an antiplasmin but was devoid of antiurokinase activity.

Animals↗
PubMed1975

Platelet antiheparin activity. The isolation and characterisation of platelet factor 4 released from thrombin-aggregated washed human platelets and its dissociation into subunits and the isolation of membrane-bound antiheparin activity.

Platelet factor 4 was isolated by gel filtration from the soluble release products of thrombin-aggregated washed human platelets as a proteoglycan-platelet factor 4 complex of molecular weight 358 000, Stokes radius (r-s) of 14.0 nm, sedimentation coefficient (s) of 7.1 S and frictional ratio (f/f-o) of 3.04. The complex was dissociated at high ionic strength (I equals 0.75) and the proteoglycan separated from platelet factor 4 by gel filtration. Platelet factor 4 had a molecular weight of 27 100, r-s of 2.52 nm, s of 2.4 S and f/f-o of 1.26, was insoluble under physiological conditions but readily soluble at pH 3. Under these conditions platelet factor 4 dissociated into four subunits with a molecular weight of 6900, r-s of 1.92 nm, s of 0.8 S, and f/f-o of 1.52. Qualitative N-terminal amino acid analysis showed the presence of glutamic acid or glutamine as the major end group. Platelet factor 4 was compared with protamine sulphate, which has similar biological properties, by electrophoresis at pH 2.2, in which both migrated as single bands but with differing mobility, and by amino acid analysis which showed a more normal distribution of residues than occurred in protamine sulphate. Of the basic amino acids platelet factor 4 (molecular weight 27 100) contained 5.97% arginine, 3.18% histidine, and 12.31% lysine compared to protamine sulphate with 64.2% arginine, 0.6% lysine and no histidine. A partial specific volume (v) of 0.747 was calculated for platelet factor 4 from its amino acid analysis. A membrane fraction with antiheparin activity, an isopycnic density of 1.090-1.110 and r-s of 15-35 nm, was also isolated by sucrose density gradient centrifugation from the ultrasonicated insoluble platelet residue remaining after thrombin-induced aggregation of washed human platelets. Trypsin treatment of the membrane fraction neither solubilised nor destroyed the activity.

Amino Acid Sequence↗