Holocene changes in sea level: evidence in micronesia.

Investigation of 33 islands, scattered widely across the Caroline and Marshall Island groups in the Central Pacific revealed no emerged reefs in which corals had unquestionably formed in situ, or other direct evidence of postglacial high stands of sea level. Low unconsolidated rock terraces and ridges of reefflat islands, mostly lying between tide levels, were composed of rubble conglomerates; carbon-14 dating of 11 samples from the conglomerates so far may suggest a former slightly higher sea level (nine samples range between 1890 and 3450 and one approaches 4500 years ago). However, recent hurricanes have produced ridges of comparable height and material, and in the same areas relics from World War II have been found cemented in place. Thus these datings do not in themselves necessarily indicate formerly higher sea levels. Rubble tracts are produced by storms under present conditions without any change in datum, and there seems to be no compelling evidence that they were not so developed during various periods in the past.

A Large Drop in Atmospheric 14C/12C and Reduced Melting in the Younger Dryas, Documented with 230Th Ages of Corals.

Paired carbon-14 ((14)C) and thorium-230((230)Th) ages were determined on fossil corals from the Huon Peninsula, Papua New Guinea. The ages were used to calibrate part of the (14)C time scale and to estimate rates of sea-level rise during the last deglaciation. An abrupt offset between the (14)C and (230)Th ages suggests that the atmospheric (14)C/(12)C ratio dropped by 15 percent during the latter part of and after the Younger Dryas (YD). This prominent drop coincides with greatly reduced rates of sea-level rise. Reduction of melting because of cooler conditions during the YD may have caused an increase in the rate of ocean ventilation, which caused the atmospheric (14)C/(12)C ratio to fall. The record of sea-level rise also shows that globally averaged rates of melting were relatively high at the beginning of the YD. Thus, these measurements satisfy one of the conditions required by the hypothesis that the diversion of meltwater from the Mississippi to the St. Lawrence River triggered the YD event.

Heterogeneity of the factor IX locus in nine hemophilia B inhibitor patients.

DNA from nine hemophilia B patients who produce anti-factor IX inhibitors (antibodies), including two brothers, was analyzed by the Southern blotting method and hybridization with factor IX cDNA, intragenomic, and 3'-flanking probes. Two inhibitor patients were shown to have total deletions of the factor IX gene. Two other inhibitor patients, the brothers, were shown to have a presumably identical complex rearrangement of the factor IX gene involving two separate deletions. The first deletion is of approximately 5.0 kb and removes exon e. The second deletion is between 9 and 29 kb and removes exons g and h but leaves exon f intact. An abnormal Taq I fragment at one end of the deletion junctions acted as a marker for the inheritance of hemophilia B in the patients' family. Five other inhibitor patients have a structurally intact factor IX gene as detected by this method. Our studies indicate that whereas large structural factor IX gene defects predispose hemophilia B patients to developing an anti-factor IX inhibitor, the development of an inhibitor can be associated with other defects of the factor IX gene.

The dissociation of factor VIII by reducing agents, high salt concentration and affinity chromatography.

Incubation of a factor VIII-rich fraction of plasma with a high concentration of salt confirmed the production of both high (HMW) and low (LMW) molecular weight factor VIII clotting activity (FVIIIC) as determined by agarose gel filtration but with considerable overlap. The electrophoretic mobility of factor VIII related protein (FVIIIRP) detected by precipitating rabbit antiserum was not affected by this treatment and LMW FVIIIC devoid of FVIIIRP was apparently produced. At low concentration the reducing agent dithiothreitol (DTT) altered the electrophoretic mobility of FVIIIRP. At higher concentrations it altered both its mobility and antigenicity and an LMW FVIIIRP was produced. Contrary to the findings of other workers no LMW FVIIIC devoid of FVIIIRP was produced. In further studies factor VIII-rich plasma fraction was treated with sepharose beads to which had been coupled a non-coagulation inhibitory precipitating rabbit antibody to FVIIIRP. Both FVIIIRP and FVIIIC were taken up by the beads but after elution with 1.5 M NaCl, FVIIIC of LMW and devoid of FVIIIRP was selectively removed. Antisera raised to LMW FVIIIC produced with 1.5 M NaCl either by the gel filtration or affinity chromatography methods inhibited FVIIIC and precipitated with HMW factor VIII-rich fractions. The results were consistent with the possibility that factor VIII clotting activity and FVIIIRP exist in plasma as a non-covalently bound complex.

Fibrinolytic, factor VIII and pulse rate responses to repeated adrenaline infusion followed by haemorrhage.

The role of catecholamines in the activation of coagulation and fibrinolysis following surgery remains controversial. In this study 5 dogs were infused with 1,2,3,6,9 and 12 microgram kg-1 min-1 of adrenaline at twice weekly intervals and were then reexposed to 3 microgram kg-1 min-1. Pulse rate and factor VIII increased after infusion of 1,2 and 3 microgram kg-1 min-1 but thereafter there was a diminished response and no response on reexposure to 3 microgram kg-1 min-1 although this was not significant in the case of pulse rate. Euglobulin lysis time shortened after each infusion of adrenaline and showed no development of tolerance. A control series of dogs infused with saline showed no similar changes. Both groups of animals were then bled to a blood pressure of 60 mm Hg for 60 minutes. Pulse rate and factor VIII did not change but euglobulin lysis time shortened in both groups. The results suggest that the activation pathways for changes in factor VIII and euglobulin lysis time induced by adrenaline are separate.

The application of a monoclonal antibody to factor VIII related antigen (VIIIRAg) in immunoradiometric assays for factor VIII.

A two site solid phase immunoradiometric assay (IRMA) for VIIIRAg has been developed using a monoclonal antibody as both the solid phase ligand and the radiolabelled antibody. A range of normal plasmas and von Willebrand's disease (vWd) plasmas has been assayed for VIIIRAg by this method and compared with VIIIRAg values measured by an IRMA using polyclonal antibodies and by immunoelectrophoresis and with ristocetin cofactor activity (VIIIRiCoF). It was found that the monoclonal IRMA correlated well with the polyclonal IRMA and the immunoelectrophoretic assay, but the correlation with the VIIIRiCoF assay was relatively poor, in spite of the strong inhibitory effect of the antibody on VIIIRiCoF activity.

Factor VIII inhibitor and bronchogenic carcinoma.

An inhibitor to procoagulant factor VIII (FVIIIC) developed in a patient three years after palliative resection of a bronchogenic carcinoma. The inhibitor was not active against ristocetin cofactor but possibly had some activity against factor XI. It responded to immunosuppressive therapy. This is apparently the first reported association of carcinoma and factor VIII inhibitor.

Platelet and coagulation function in patients with abnormal cardiac valves treated with sulphinpyrazone.

Eight patients on warfarin with rheumatic heart disease and prosthetic cardiac valves were selected for study on the basis of persistently elevated plasma beta-thromboglobulin (beta-tg) and platelet factor 4 (PF4) concentrations. Platelet mean lifespan and fibrinogen half life were short, and positively correlated, and both were inversely related to the plasma concentration of the platelet specific proteins. Antithrombin III (ATIII) levels were also reduced. Treatment with sulphinpyrazone resulted in lengthening of both platelet and fibrinogen survival, a rise in ATIII but no change in the beta tg or PF4 concentrations. It is concluded that patients with abnormal cardiac valves and raised plasma levels of beta tg or PF4 have, despite warfarin, a consumption coagulopathy that can be inhibited by sulphinpyrazone.

von Willebrand factor: clinical features of inherited and acquired disorders.

The physiologic mechanisms that influence plasma levels of von Willebrand factor (vWF) are poorly understood but include race, blood group, age, pregnancy, exercise, and adrenergic and neurohumoral stimuli. Inherited abnormalities in von Willebrand's disease (vWD) are associated with a defect of the vWF gene on chromosome 12, but in some cases, coexistence of impaired response of plasminogen activator and telangiectasia suggests the presence of a regulatory defect or more extensive endothelial perturbation. Three broad types of vWD are recognized; in addition, a platelet-type vWD (pseudo-vWD) is due to an abnormal platelet receptor for vWF. The prevalence of vWD, which is difficult to determine because of variations in severity even within a kindred, is reportedly as high as 1%. In a survey of European patients, the prevalence of treated vWD varied from 4.5 to 24 per million. Preliminary results of an international survey of vWD indicate that about 3% of treated patients have seroconversion to human immunodeficiency virus, 50% of whom have symptoms. Inhibitor of vWF occurs in type III vWD after treatment and is associated with the presence of gene deletions. Acquired vWD may complicate lymphoproliferative and autoimmune disorders, and proteolytic degradation of vWF complicates myeloproliferative disorders. The level of vWF is increased during pregnancy and in vascular and other disorders; it may be involved in the pathogenesis of atherosclerosis. High-molecular-weight multimers of vWF and a cofactor are thought to promote the formation of microthrombi in thrombotic thrombocytopenic purpura and the hemolytic uremic syndrome. Thus, study of vWD has shed light on pathogenetic mechanisms in a wide range of disorders.

Failure of factor VIII inhibitor bypassing activity (Feiba) to secure haemostasis in haemophilic patients with antibodies.

Factor IX concentrates have been widely advocated in the treatment of haemophilic patients with factor VIII inhibitors. Five such patients were given the 'activated' factor IX concentrate--factor VIII inhibitor bypassing activity (Feiba)--for 14 separate bleeding episodes. In six of the episodes, including two with external blood loss, bleeding progressed in spite of treatment. In none of the other eight episodes was there a prompt response, and it was not possible to ascribe a definite therapeutic effect.

Relationship of platelet retention in glass bead columns to the rate of aggregation with adenosine diphosphate and thrombin.

The initial rate of platelet aggregation induced by adenosine diphosphate and thrombin correlated with the number of platelets retained when samples of citrated blood from the same normal donors were passed through glass bead columns. The results support the view that the glass bead column method of measuring platelet ;adhesiveness' is influenced by platelet aggregation.

A study of two methods for estimating plasma fibrinogen and the effect of epsilon aminocaproic acid and protamine.

Fibrinogen concentrations were determined in normal plasma and in plasma from patients with high and low levels. There was a good correlation between the results of a rapid semi-quantitative fibrinogen titre technique and those of a quantitative assay of coagulable fibrinogen. In normal subjects fibrinogen levels were not significantly influenced by taking blood into epsilon aminocaproic acid (EACA) or by the addition of protamine to plasma. In patients with the defibrination syndrome in whom increased plasma fibrinolysis was not detected, fibrinogen levels were not affected by taking blood into EACA but considerably increased levels were observed after the addition of protamine to plasma. In patients undergoing thrombolytic therapy the fibrinogen levels measured were increased both in blood taken into EACA and in plasma containing protamine. It is suggested that EACA acted by preventing lysis in vitro whilst protamine counteracted abnormal fibrin polymerization. The pattern of results may be of diagnostic importance.

Adenosine diphosphate and the measurement of platelet adhesiveness.

Platelet adhesiveness to glass beads was measured in citrated blood at intervals up to two hours after the addition of adenosine diphosphate (A.D.P.). Adhesiveness increased for 15 minutes, fell towards the original level, and then steadily increased. The initial changes were associated with the formation and subsequent dispersal of platelet clumps. The sequence of events resembled the reported platelet aggregation, the disaggregation and secondary aggregation effect of A.D.P. and emphasizes the importance of a standard technique in the measurement of A.D.P.-induced platelet adhesiveness.

Coagulation studies in haemophilic patients taking oral contraceptives.

Coagulation studies were performed on haemophilic patients during a controlled trial of oral contraceptive therapy. Treatment with a combined oestrogen-progestogen preparation was associated with a significant rise in the factor VII-X complex. This change was not observed during treatment with progestogen alone. The highest levels of factor IX and fibrinogen and the lowest levels of factor X were observed during the first period of the trial but these effects were independent of the type of treatment. The results suggest that the effects of oral contraceptives on blood coagulation in haemophilic males are similar to those observed in normal females and that the changes are due to the oestrogenic component.

A clinical and experimental study of platelet function in chronic renal failure.

Coagulation and platelet function studies were performed on 24 normal subjects and 29 patients with chronic renal failure due to various causes. Thrombocytopenia was uncommon in the uraemic patients but there was reduced platelet retention in glass bead columns and platelet aggregation with adenosine diphosphate (ADP) and thrombin was slower and less complete than normal. The rate of platelet disaggregation in uraemic patients was significantly reduced. The abnormalities tended to be more severe in more uraemic subjects. In normal subjects no inter-relationships were observed between the various measurements of platelet activity. In patients there were significant interrelationships between the measurements of platelet aggregation with ADP and thrombin and between the measurements of aggregation and retention in glass bead columns. It is suggested that if a common pathway is involved in these reactions it is adversely affected in uraemia. Plasma coagulation defects were uncommon and present in only five of the uraemic subjects. Impaired prothrombin consumption apparently due to defective platelet function was present in half the patients but was not detected by a kaolin activation method. Although platelet coagulation function was activated during ADP aggregation and disaggregation in normal and uraemic subjects, it did not correlate in the latter with impairment of aggregation. It is suggested that aggregation and activation of platelet coagulant activity are not necessarily related aspects of platelet function. An effect of uraemic plasma on normal platelets was demonstrated by mixing experiments consistent with a humoral cause for the uraemic platelet defects.

Coagulation studies in massive pulmonary haemorrhage of the newborn.

Coagulation studies were performed on two newborn infants with fatal massive pulmonary haemorrhage. The first showed a reduced level of plasma fibrinogen with defective thrombin-fibrinogen reaction, corrected by protamine, and defective thromboplastin generation. In the second case, a premature infant, the fibrinogen level was normal but there was a severe defect in thromboplastin generation with evidence of an inhibitor. A relationship between the pulmonary haemorrhage and coagulation defects is suggested but not established.

Comparison of qucik and slow thaw methods of producing cryoprecipitate antihaemophilic factor from fresh and 24-hour-old blood.

Cryoprecipitate antihaemophilic factor concentrate was prepared from fresh and 24-hour-old blood by quick and slow thaw methods. Recovery of factor VIII was greater by the slow thaw method and there was less loss into the supernatant plasma. Cryoprecipitate produced from fresh blood contained more factor VIII than that produced from 24-hour-old blood so that the most potent concentrate was produced from fresh blood by the slow thaw process. An adequate therapeutic preparation was, however, produced by the slow thaw method using 24-hour-old blood and it is suggested that this procedure could be adopted in order to supplement supplies.

Differential localisation and synthesis of porcine factor VIII related antigen (VIIIR:AG) in vascular endothelium and in endothelial cells in culture.

Porcine and human umbilical vein and adult blood vessels were studied for the presence and synthesis of factor VIII related antigen (VIIIR:Ag) and fibronectin (Fn) by immunofluorescence histology and immunoautoradiography. Investigation of human tissue confirmed the widespread distribution of VIIIR:Ag on the endothelium of all blood vessels examined but observations on porcine tissue gave different results. Porcine umbilical vein and porcine adult veins were positively stained for VIIIR:Ag whilst porcine aorta and other pig arteries appeared to be negative or only weakly positive. Some blood vessels (?venous) in the adventitia of porcine aorta were positively stained whilst adjacent ones (?arterial) were negative. Radiolabelled methionine was added to culture medium and proteins synthesised by cultured EC were examined by two dimensional crossed immunoelectrophoresis and autoradiography. Identification of radiolabelled precipitin arcs provided a highly sensitive method for confirming the specificity of antisera and for detecting VIIIR:Ag and Fn. Examination of cultured human umbilical vein EC confirmed the synthesis of VIIIR:Ag and distinguished between VIIIR:Ag and Fn. Studies of porcine umbilical vein EC in culture gave similar results to those observed with corresponding human EC. However, cultures derived from porcine aorta did not demonstrate synthesis of VIIIR:Ag and microscopy failed to locate VIIIR:Ag in these cells with certainty. The results confirmed the synthesis of VIIIR:Ag by human and porcine umbilical vein EC but differences in staining reactions and the apparent inability to synthesise VIIIR:Ag by cells derived from porcine aorta suggested that porcine EC at different anatomical sites may subserve different functions.