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Biomedical subjects

C Rothschild

Publications and source records attributed to C Rothschild.

At least 73 records · Page 4Linked to original sources

Clinical application of a chromogenic substrate method for determination of factor VIII activity.

A chromogenic substrate kit for the determination of factor VIII activity (COATEST Factor VIII) has been evaluated in five different laboratories, one of them using a semi-automated procedure. This chromogenic method was compared to one-stage clotting assays for factor VIII determination in plasmas from healthy subjects, carriers of hemophilia A, severe, mild and moderate hemophilia A as well as von Willebrand's patients. In all these cases, a high correlation between these two methods was obtained (r = 0.96-0.99, n = 385) with a good agreement of the assigned potencies at all levels of factor VIII. A good correlation (r = 0.94) was also obtained for the levels of factor VIII after infusion of concentrates in six severe hemophiliacs or after administration of DDAVP to von Willebrand's patients. The chromogenic method is insensitive to preactivation of factor VIII by thrombin, thus yielding valid potency assignments also in these situations. The precision was higher with the chromogenic method than with the one-stage clotting assays (C.V. = 2-5% vs 4-15%). Altogether, the new chromogenic substrate method has proven itself suitable for determination of factor VIII in plasma and concentrates.

Blood Coagulation Tests↗

A new method for the estimation of protein C by ELISA.

A new solid phase enzyme-linked immunosorbent assay (ELISA) was developed for the quantitation of human protein C antigen. Anti-protein C F(ab')2 fragments were adsorbed to polystyrene plates. The binding of serial dilutions of control or test plasma, containing protein C, was detected by incubation with peroxidase-labeled anti-protein. C-IgG followed by the addition of hydrogen peroxyde and 0-phenylenediamine. This ELISA is specific, sensitive (detection limit: 0.02%) and accurate (variation coefficient: 3 to 10%). When results are compared to those obtained by the Laurell technique (electroimmunodiffusion, EID), the correlation coefficient is 0.95 in all tested plasmas. Protein C antigen was measured by ELISA and EID in plasma from 40 controls, 14 patients with congenital protein C deficiency, 15 patients with liver cirrhosis and 40 dicoumarol-treated cases. In normal plasma, protein C ranged from 70 to 126%. In congenital deficiency, protein C was between 35 and 58% in 13 cases and 9% in one of them. In patients with liver cirrhosis and dicoumarol-treated cases, levels of protein C antigen were compared to those of other vitamin K dependent factors, i.e. Factors II and IX measured by EID and Factor X assayed by EID and ELISA. In liver cirrhosis, the amount of protein C was significantly lower than that of Factors II, IX and X. In short-term and long-term dicoumarol-treated patients, the highest correlation (r = 0.72) was observed between protein C and Factor X levels. In the plasma of patients undergoing oral anticoagulant therapy, protein C decreased more rapidly than Factors X or II and migrated in presence of calcium as a double peak, one with a normal mobility and one more anodal corresponding to the non carboxylated form of protein C.

Antigens↗

[The factor VIII complex: hemophilia A and von Willebrand disease].

The factor VIII complex is a macromolecule with two distinct components. One is the coagulation factor VIII. The other, known as the Willebrand factor, is a polymer which probably acts as a carrier for serum factor VIII. Hereditary disorders can affect either of these two components. Hemophilia A is a coagulation disorders due to decreased factor VIII coagulant activity. Increase of partial activated thromboplastin time parallels disease severity. Hematomas and hemarthrosis in large joints are the main clinical features. In von Willebrand disease, mucocutaneous bleeding is the main symptom. Diagnosis is established by demonstrating disorders of primary hemostasis: prolonged bleeding time and decreased ristocetin-induced platelet aggregation. Two forms of von Willebrand disease have been described. In the quantitative form, decreased synthesis of von Willebrand factor is often responsible for severe clinical manifestations. The qualitative form probably results from defective polymerization of von Willebrand factor subunits. In both these forms, deficient primary hemostasis is a consequence of decreased platelet adhesion to the vascular wall. Clinical and biological features of hemophilia A and von Willebrand disease, as well as their management, are discussed.

Blood Coagulation Tests↗

Biphasic change in serum potassium concentration following a single dose of succinylcholine chloride.

Serum potassium concentration during the thiopentone-succinylcholine induction of endotracheal anesthesia was examined in 53 patients undergoing elective surgery. There was no change in serum potassium after thiopentone. During muscle fasciculation serum potassium fell by 0.37 meq/L and returned to the initial level by the end of fasciculation. During muscle relaxation there was a further rise of 0.41 meq/L. The expected increase in serum potassium following the administration of succinylcholine is shown to be preceded by a transient decrease.

Adolescent↗

Skeletal clues apparently distinguishing Waldenstrom's macroglobulinemia from multiple myeloma and leukemia.

This study was conducted to characterize macroscopically and by conventional radiography the bony lesions in a case of Waldenstrom's macroglobulinemia and to compare and contrast it with those of the other major hematologic lymphoproliferative disorders, multiple myeloma and leukemia. Two varieties of lytic skeletal lesions were found in Waldenstrom's macroglobulinemia. One was sharply defined, spheroid lesions with smooth borders and effaced/erased trabeculae. The second was in the form of coalescing pits (holes) with smooth, minimally remodeled edges. The appearance combined features of multiple myeloma and leukemia, but were mutually exclusive in those diseases. Spheroid lesions with effaced edges were absent in leukemia, while pits were absent in multiple myeloma. Fronts of resorption were not noted in Waldenstrom's macroglobulinemia. The combination of some of the features of leukemia and myeloma appear to allow recognition of Waldenstrom's macroglobulinemia.

Bone and Bones↗

Differential distribution of von Willebrand factor in endothelial cells. Comparison between normal pigs and pigs with von Willebrand disease.

Endothelial cells were cultured from the thoracic aorta, inferior vena cava, and pulmonary artery of normal adult and young pigs as well as from pigs with von Willebrand disease (vWD). The von Willebrand factor (vWF) was estimated by ELISA in endothelial cell supernatants and lysates as well as by immunofluorescence of cells by use of either a polyclonal or a monoclonal antibody to vWF. In normal adult pigs, the content of vWF in supernatants and cell lysates was the highest in the pulmonary artery, lower in the inferior vena cava, and almost nil in the thoracic aorta. In the normal young pigs, vWF was higher in the inferior vena cava endothelial cell supernatants and lysates than in the pulmonary artery. Thus the synthesis of vWF by endothelial cells varies along the vascular tree and appears to be modulated by the age of the animals. In pigs with vWD, levels of vWF were slightly detectable in endothelial cells from the pulmonary artery (contrasting with levels of plasmatic vWF below 0.01 U/ml), but were undetectable in the thoracic aorta and inferior vena cava. Thus, if vWF plays a role in atherogenesis, this involves circulating, not its intracellular, form.

Aging↗

[Clues to recognition of kidney disease in archaeologic record: characteristics and occurrence of leontiasis ossium].

The possible osseous effect of kidney dysfunction was evaluated in a modern skeletal population for future use in assessment of archaeologic samples. Frequency and distribution on the bones of cysts, articular surface alterations, subperiosteal resorption, porosity, osteochondritis, digital tuft alteration and periosteal reaction were recorded in 94 individuals with known kidney failure in the Hamann-Todd collection. Independent radiologic analysis was also pursued. The results were compared with a control sample. The pattern of joint surface alteration and periosteal reaction may facilitate recognition of chronic renal disease in the osseous record. Subtle manifestations of leontiasis ossium are present in the form of cranial thickening and increased cranial size and weight, but teeth spacing are rare. Pseudo osteomatous lesions are common. This study perhaps explains the apparent rarity of actual leontiasis ossium.

Aged↗

Origins of spondyloarthropathy in Perissodactyla.

OBJECTIVE: Spondyloarthropathy has clearly been documented as not limited in occurrence to humans. Transmammalian in nature, it is of interest to understand the antiquity, and perhaps the origins, of this disorder in animal groups sufficiently represented in the skeletal record. METHODS: Fossil and recent skeletons of perissodactylae from North America were systematically examined to determine the occurrence and population frequency of spondyloarthropathy. RESULTS: Spondyloarthropathy was the most common form of arthritis recognized in the extant and fossil records. Common in extinct families such as Brontotheriidae and Chalicotheriidae, a progressive increase in the frequency of spondyloarthropathy was observed through geologic time in Equidae and Rhinocerotidae. CONCLUSION: Erosive arthritis of the spondyloarthropathy variety is now documented as not only persisting in Perissodactyla, but as actually increasing significantly in frequency (3-6 fold). Given the unusual evolutionary penetrance of this "disease," the possibility must be considered that its persistence provides evidence for some unknown benefit to the affected host.

Animals↗