bluuebunny/crossref_metadata_2025 huggingface dataset:
Heated Lyophilized Factor VIII And Factor IX Concentrate Preliminary In Vitro Studies
Authors: Rubinstein A
Published: July 2018

It has been known that albumin and plasma protein fraction (PPF) do not transmit hepatitis since these products are heated at 60°C for 10 hours. This heating is sufficient for inactivation of hepatitis virus. It has been previously tried to heat the Cohn Fractions leading to Factor VIII and Factor IX Concentrates in solution, however, this has resulted in significant loss of Factors VIII and IX.

We have taken lyophilized Factor VIII Concentrate powder and heated it in a waterbath at 60°C for 10 hours and have demonstrated no significant change in in vitro recovery of Factor VIII activity four hours following the heating. The same was shown for recovery of Factor IX activity after heating lyophilized Factor IX concentrate for 10 hours at 60°C. In addition Factor IX activity was not destroyed following heating of the lyophilized powder for 20-30 minutes at 100°C. This is significant because now potentially this heated lyophilized powder of Factor VIII and Factor IX is free of previous risk of transmission of hepatitis. However, the effect of heating on the thrombogenic effects in vivo of the concentrates and complications was not assessed in this study. Chimpanzee studies are planned to determine whether the heating has inactivated the hepatitis virus.

It is possible that a longer heating time will be needed to sufficiently inactivate the hepatitis virus in the lyophilized state.
Platelet Factor V-Like Coagulant Activity And Catalytic Phospholipid-Like Surface Activity In Clotting And Chromogenic Assays
Authors: Dombrose F A , Bode A P , Sandbergt H , Lentz B R , Jones M E , Crumpler D C
Published: July 2018

The role of the platelet membrane as a catalytic surface in thrombin generation was studied, in vitro, using normal and F.V-deficient human plasmas. Frozen-and-thawed lysed platelet supernatant from normal or V-deficient donors was used as a reference for physiologic activation, in vitro. Coagulant activities were evaluated by both a clotting test (based on the KAPTT, in which the kaolin suspension was removed prior to recalcification) and by assessing thrombin formation (based on the maximum rate of hydrolysis of S-2238). The degree to which the clotting time was shortened or thrombin formation was enhanced was taken as overall catalytic surface activity. In both tests, log-log plots of the dependent variable as a function of the dilution of a given membrane preparation were linear over several orders magnitude (p >.25). The slopes of such plots were taken as overall catalytic surface effectiveness and were dependent on both the parametric level of F.V and the nature of the membrane. For the same membrane preparation, effectiveness in the clotting test was highly negatively correlated (-r >0.9) with effectiveness in the S-2238 system (i.e., clotting time was inversely proportional to the maximum amount of thrombin generated). The change in effectiveness as a function of the parametric level of F.V was taken as the sensitivity of that surface to F.V. For a given control, both test systems appeared to be equally sensitive to the parametric level of F.V. On the basis of differences in catalytic effectiveness, it was possible to distinguish qualitatively between membrane associated F.V- like activity (platelet factor 1) and phospholipid-like catalytic surface activity (platelet factor 3). Discrete clotting time measurements, like single thrombin determinations, can not adequately describe the catalytic contribution of the platelet membrane in thrombin generation.
Use Of Chromogenic Peptide Substrate Assays In The Evaluation Of Surgical Treatment Of Intraabdominal Sepsis
Authors: Smith-Erichsen N , Aasen A O , Amundsen E
Published: July 2018

Chromogenic peptide substrate assays were included in the evaluation program of 14 patients having surgical treatment for intraabdominal sepsis.

Six of the patients survived, whereas eight died. The six survivors had a total of 19 operations (1-5 operations /patient). The eight fatal cases had a total of 14 operations (1-2 operations/patient). Plasma prekallikrein (PKK), functional antikallikrein (KKI), plasminogen (Pig), fast antiplasmin (AP) and functional antithrombin III (AT- III) values were determined using chromogenic peptide substrate assays. Hageman factor levels (HF) were determined using a coagulation assay with a HF deficient plasma. α2-Antiplasmin (α2AP), CI-esterase inhibitor (CIINH), α2- Macroglobulin (α2M) and AT III were determined immunochemically.

In both the fatal cases and the survivors PKK, HF, Plg and AT III values were found markedly reduced during sepsis. The reductions of PKK and AT III were significantly more pronounced in the fatal cases than in the survivors. During sepsis the ratio of functional activity versus immunochemical values decreased when compared with normals for α2AP, CIINH and AT III. Whereas the parameters remained reduced in the fatal cases, gradual increases towards normal values for PKK, HF, Plg and AT III were found within two weeks in the survivors. Clinically and by autopsy all the fatal cases were evaluated to have a persistant intraabdominal septic focus.

It is concluded that chromogenic peptide substrate assays appear to be of great value in evaluating surgical treatment of intraabdominal sepsis.
Studies On The Various Causal Factors Related To Hypercoagulability In The Field Of Obstetrics. With Special Reference To The Onset Of Dic As Viewed From The Changing Of Kinin-Kallikrein System And Fibrinopeptide A
Authors: Suzuki S , Murakoshi T
Published: July 2018

Purpose: In order to follow the changes accompanying the develop of the foetus and placenta which has the activation of thromboplastin in its background, in addition to the studies on hypercoagulability done hitherto, the changing of the Kinin-Kallikrein system were investigated. This changing of the Kinin-Kallikrein system is controlled by Hageman factor which is considered to be the source of coagulation. The change of Kinin-Kallikrein system was investigated along the gestational monthes. On the other hand, from fibrinogen and its metabolized products which are considered to be the precursor of FDP and which is involved in the 3rd stage of coagulation especially from increasing and decreasing of Fibrinopeptide A(FPA) and the Soluble Fibrin Monomer Complex (SFMC) the hypercoagulability was analysed, and prediction of DIC was attempted.

Method: 70 cases of pregnancies (30 cases of delivery, 12 cases of premature separation of the placenta, 13 cases of abortion, 15 cases of EPH-Gestosis.) were examined and i) Kininogen(by Bioassay and Radioimmunoassay) and prekallikrein(S-2302) which are the control-substances of the KininKallikrein system were measured, ii) Fibrinopeptide A was measured by Radioimmunoassay and SFMC was measured with Agarose Gelfiltration.

Results: i) As in the case of the majority of the coagulation factors, Kininogen, and Prekallikrein showed a definite increase during pregnancies, and it was noted that at the end of pregnancies prekallikrein showed values of 190.0±31.6 %(normal values 90-110%) and at the onset of labour pains the values showed a lowering to (76.5±12.6%) and especially it was noted that in the DIC group the values were remarkably low(38.6 ±8.8%). ii) Both Fibrinopeptide A and SFMC showed a remarkable increase (14.0±5.1 ng/ml-FPA, normal value under 2 ng/ml) and in DIC cases a still further remarkable increase of 26.0±6.8 ng/ml was seen.
Study Of The Ratio Expression For Prothrombin Time And Activated Partial Thromboplastin Time Results
Authors: Leclercq R
Published: July 2018

Prothrombin time (PT) and activated partial thromboplastin time (APTT) results are statistically different, not only in function of reagent used but also, with a same reagent, in function of the degree of automation of the measuring device. It has been claimed that using time ratio of pathological to normal samples would reduce these discrepancies.

In a national voluntary quality control program using Verify Citrate Normal and Pathological I/II plasmas, pairs of results obtained in the same analytical batch were computed to compare mean values and reproducibility of ratios and seconds for both PT (n=1764) and APTT (n=1392). Results were screened simultaneously for origin of reagent and measuring technique.

Concerning PT, the ratio expression did not improve the intralaboratory dispersion of results for both pathologies levels. Neither in group comparisons between couples reagent-device, nor for the whole set of pooled values, a significant improvement of the dispersion of the ratio results could be observed if compared to the dispersion expressed in seconds. In the 6 groups reagent-instrument, difference between average values was never greater than 1.0 sec for the Normal control plasma (mean: 11.7 sec), 2.4 sec for the level 1 plasma (mean: .18.9 sec) and 4.9 sec for plasma level 2 (mean: 29.3 sec).

Concerning APTT, dispersion was strongly enhanced in semi-automated equipments. Chemical activators gave times longer than the particulate ones. Here again, no significant improvement was offered by the ratios.

In conclusion, ratio expression of PT’s and APTT’s results does not abolish the influence of the couples ‘origin of reagent’ - ‘automation of measuring device’.
Platelet/Prothrombin Consumption During Whole Blood Clotting
Authors: Walz Daniel A , Love Jeffrey N , Brown Thomas R
Published: July 2018

Specific radioimmunoassays have been developed for human platelet released proteins (PF-4 and β-TG) as well as for human prothrombin activation products (fragments 1,2 and 3) in order to determine the timed appearance of platelet products relative to prothrombin consumption during coagulation. Freshly drawn whole blood was collected into glass tubes, incubated at 37C and quenched at designated intervals with an anti platelet-anti coagulant cocktail, and the plasma or serum collected. An aliquot of each sample was adsorbed on barium carbonate and the non-adsorbed (−Ba) and adsorbed (+Ba) samples assayed for fragment 2. The quantity of fragment 2 material present in the (−Ba) samples gave an index of total prothrombin activation (fragment 1-2 plus free fragment 2) whereas that quantity in the (+Ba) sample indexed thrombin activity (free fragment 2 or prethrombin 1). Control plasma samples were free of either fragment 1 or 2 and contained basal levels of PF-4 and β-TG. These whole blood fractions clotted in 9 minutes at which time less than 15% of the total prothrombin concentration had been activated. Upon coagulation, the remaining prothrombin was completely consumed in a post-clotting event. The first non-thrombin fragment formed was 1.2 and after coagulation the concentration of fragments 1.2, and free 1 and 2 increased over the next 20 minutes. Fragment 3 does not appear to be released from thrombin during whole blood clotting. Platelet activation preceeded clot formation by two minutes as monitored by the complete release of PF-4 and β-TG. The incorporation of a unique specific thrombin inhibitor, dansylarginine N-(3-ethyl 1,5-pentanediyl)amide (DAPA) into the collection tubes postponed the clotting event until 30 minutes and the release of PF-4 and β-TG until 20 minutes. However, prothrombin activation was complete (formation of fragment 1.2) in 20 minutes. Utilizing these systems, we have determined that thrombin is the sole responsible coagulation enzyme for platelet release and that thrombin has the following affinities: platelets > fibrinogen > prothrombin and/or fragment 1-2.
Thrombin Generation Stimulated By Oxidation Products Of Linolenic And Arachidonic Acids
Authors: Barrowcliffe T W , Gray E , Gutteridge J M C , Kerry P J
Published: July 2018

Autoxidation of unsaturated fatty acids yields mixtures of products which have potent biological activities in several systems. Such products have been shown to cause platelet aggregation and to stimulate thrombin generation in platelet-free plasma. The thrombin generating activity of products obtained by air or 02 oxidation of linolenic and arachidonic acids was studied by standard in vitro clotting methods. Products were separated from the starting material by a variety of techniques, the most successful being column chromatography on phenoxymethyl lipidex, a modified LH- Sephadex.

Clotting studies showed that thrombin generating activity proceeded via the intrinsic system, requiring Factors VIII, IX and X but not Factor XI. Studies with lipoprotein-free plasma indicated that part of the activity of the oxidation product was a ‘surfactant’ effect, involving release of coagulant-active phopholipid from plasma lipoproteins. Such an effect was also seen to a lesser extent with the unoxidised fatty acids. However, addition of the products to a phospholipid preparation potentiated its thrombin generating activity, indicating the release of phospholipid is not the only mechanism. The products showed marked inhibition of antithrombin III, which would result in increased amounts of thrombin being generated in plasma.

Fractionation of the products showed that the highest activity was in the most polar fractions, and the activity was inhibited by horseradish peroxidase, suggesting that peroxide groups are involved.

These studies indicate that lipid peroxides produced by non-enzymic means have potent effects on the plasma coagulation system, and suggest the possibility that the endoperoxides produced enzymically by platelets could also be involved in plasma coagulation.
Clinical And Laboratory Observations In Congenital Factor VII Deficiency
Authors: Kernoff L M , Hughes J , Denson K
Published: July 2018

Four generations of a kindred suffering from congenital Factor VII deficiency have been studied. The defect is transmitted as an autosomal recessive character with homozygotes having < 1% Factor VII procoagulant activity, and heterozygotes between 20-50%. Homozygotes suffer from epistaxis, menorrhagia, easy bruising, haemarthrosis, and excess bleeding after dental extraction. Heterozygotes are asymptomatic. Antibody neutralisation tests using a monospecific rabbit antihuman Factor VII antibody demonstrated in the three homozygotes and their heterozygous parents the presence of Factor VII antigen in excess of Factor VII procoagulant activity. The abnormality is therefore the result of a functionally abnormal molecule and not a true deficiency of Factor VII. When the homozygous plasmas were tested in the prothrombin time test, a progressive diminution in sensitivity to the Factor VII deficiency was observed with human, rabbit and ox tissue thromboplastins. Differences were however small and the total insensitivity to ox brain thromboplastin characteristic of Factor VII Padua was not observed.
The Anti-Xa Activity Of Lipoproteins
Authors: Barrowcliffe T W , Eggleton C A
Published: July 2018

The major plasma inhibitor of Factor Xa is thought to be antithrombin III (At III). However, adsorption of plasma by aluminium hydroxide [Al(OH)3) increases its rate of Xa neutralisation 7-8 fold, and this ‘fast-acting’ anti-Xa activity has been shown to be independent of At III. We have carried out studies to determine the nature of the plasma components responsible for this increased anti-Xa activity after adsorption by Al(OH)3.

Gel filtration of plasma indicated that the anti-Xa activity after Al(OH)3 adsorption was located largely in the high molecular weight (> 200,000) fractions. These fractions contain most of the plasma lipoproteins, and previous reports have indicated a connection between anti-Xa activity and lipoproteins, particularly those of low density. Purified very-low-density (VLDL), low-density (LDL) and high density (HDL) lipoproteins were prepared by ultracentrifugation, and characterised by polyacrylamide gel electrophoresis, cholesterol and phospholipid analyses. The lipoproteins were checked for lack of contamination with At III and α2-macroglobulin, and their anti-Xa activities measured before and after Al(OH)3 adsorption.

LDL had a small but significant anti-Xa activity which increased with concentration; VLDL and HDL had virtually no activity. After Al(OH)3 adsorption of the lipoproteins, the activities increased, LDL giving the highest activity. Delipidation of the adsorbed LDL with fumed silica removed its anti-Xa activity.

These results suggest that lipoproteins, especially LDL, contain binding sites for Factor Xa. The binding sites are related to the lipid content of the lipoproteins, and are exposed by Al(OH)3 adsorption. The fast-acting anti-Xa activity produced by Al(OH)3 adsorption of plasma is largely due to LDL.
Characterization Of Soluble DES-A And DES-AB Fibrin In Human Plasma At 37°C By Agarose-Gel Filtration
Authors: Müller-Berghaus G , Bernhard J-C , Mahn I
Published: July 2018

In two consecutive steps, thrombin cleaves the fibrinopeptides A and B from fibrinogen producing des-A fibrin and des-AB fibrin. Labeled des-A fibrin was prepared by batroxobin and labeled des-AB fibrin by clotting of 125I-fibrinogen with thrombin. Fibrin solubilized in buffered urea was mixed with plasma containing 131I-fibrinogen (fibrin:fibrinogen ratio = 1:20). These fibrinfibrinogen mixtures were applied to sepharose CL- 6B columns eq ui librated with buffered plasma (0.0025 M EDTA, 0.1 M NaCl, 0.05 M tris, 0.005 M EACA, 2 AT U hirudin/ml, 500 KIU a protinin/ml, 0.003 M NaN3, pH 7.4). Plasma was used as an equilibration and elution medium to prevent precipitation of fibrin in the columns. At 20°C, labeled des-A fibrin as well as des-AB fibrin were eluted in the void volume as high-molecular weight aggregates (peak A) and separated from m onomeric labeled fibrinogen (peak B). At 37°C, however, des- A fibrin was eluted at the same position as monomeric fibrinogen (peak B), whereas des-AB fibrin was eluted in the void volume as at 20°C. Rechromatography of isolated fractions of peak A and peak B at different temperatures showed that monomeric fibrin isolated at 37°C formed high molecular weight material at 20°C, and high-molecular weight fibrin isolated at 20°C dissociated at 37 ° C. The results suggest that des-A fibrin solubilized in plasma in the absence of calcium ismonomeric at 37°C but forms high-molecular weight aggregates at lower temperature, whereas des-AB fibrin is oligomeric at 20°C as well as at 37°C.
High Molecular Weight Complexes Derived From Fibrinogen
Authors: Alkjaersig N , Fletcher A
Published: July 2018

Fibrinogen, 3×10-5 M, incubated at 25°C with thrombin 10-10 M, is slowly transformed to fibrin. Fibrinopeptide A (FPA) is released at a rate of approximately 1 nM/ml per min, and after 30 min a clot is formed. Prior to clot formation serially timed solution aliquots were examined by gel permeation chromatography on a Bio Gel 5M column (void volume 140 ml). High molecular weight complex concentration and molecular size increased with incubation time. Fibrinogen antigen and FPA concentration was determined for each effluent fraction and relative FPA content (ng FPA/μg fibrinogen equivalent) was linearly related to chromatographic effluent volume between 160 and 260 ml (Ve for fibrinogen 255 ml). Computer analysis of the effluent profiles indicated a linear fall in monomeric fibrinogen to 20% of original concentration, a linear increase in “fibrin” dimer (2 fibrinogen equivalents with 2 FPA) to 30% and in trimer (3 fibrinogen equivalents with 2 FPA) to 20% of original concentration with higher polymers accounting for the remaining protein. These complexes were stable and remained in solution after fractionation. Fibrin monomer, in 3 M urea and devoid of FPA, when added to fibrinogen resulted in clot formation, equivalent to 66% of added monomer, but minimal complex formation, 5% of total fibrinogen equivalents. Thus intermediate fibrin polymers which contain residual FPA are stable soluble molecular entities in contradistinction to fibrin monomer lacking FPA. Fibrin proteolysis products added to fibrinogen also show minimal complex formation with fibrinogen if the products are free of thrombin and FPA. Patient plasma samples can be similarly assayed and distinction can be made between high molecular weight complexes derived from fibrinogen through thrombin action or from fibrin through plasmin action.
Regulation Of Soluble Fibrin By Shear Rate
Authors: Puryear H A , Clark H G , Sellers J P
Published: July 2018

The reaction of fibrinogen and thrombin has been carried out in a Couette-flow apparatus over a range of rates of shear from 0-150 s-1 and at pH’s from 6.4 - 6.8. A minimum is found in the rate of formation of insoluble fibrin at shear rates of 30-60 s-1 (well within the physiological range). The position of the minimum is determined by the concentration of reactants. Rate decreases of up to 50% have been observed. Hirudin quenching of thrombin activity shows that formation of fibrin monomer is unaffected by shear rate, hence the effect is due to changes in fibrin aggregation. The same sort of minimum has been observed when a solution of fibrin monomer is made to precipitate by altering pH and ionic strength in shear fields. The release of B-peptide as analyzed by HPLC appears to be less at the minimum.

These results are interpreted as resulting from a lowering of the growth of fibrin particles at low shear rate and an increase in nucleation of particles at higher shear rates.
Effect Of Ionic And Non-Ionic Contrast Media On Components Of Coagulation And Complement Pathways
Authors: Moncada R , Parvez Z , Fareed J , Agrawal P , Messmore H L
Published: July 2018

The effects of a recently developed non-ionic contrast media (CM) P-297 and two ionic forms Ioxigalic acid and Iothalamic acid (Laboratoire Guerbet, Paris, France) were studied on coagulation and complement systems, and their interactions with anticoagulant drugs. In coagulation studies, a 1:10 mixture of P-297 (10%) in human plasma (both normal and abnormal) was prepared and prothrombin time (PT), partial thromboplastin time (PTT), and thrombin time (TT) were determined. Similar studies were performed with Ioxigalic acid (10%), and Iothalamic acid (10%). Separate pools of (10) individual plasmas representing disorders of intrinsic and extrinsic pathways of coagulation were similarly mixed with CM and the clotting times were determined. In all of these experiments, there was only a slight increase in TT whereas PTs and PTTs were not affected. Of the three CM tested, P-297 (10%) showed considerably less anticoagulant action than ioxigalic and iothalamic acids. All the CM exhibited a synergistic effect with 0.2u/ml heparin and greatly prolonged (>100 secs.) all coagulation tests. All of the three CM at (10 mg/ml) failed to produce any significant blockade of thrombin-induced aggregation of platelets, however at 40-80mg/ ml level did block thrombin-induced aggregation. In complement activation studies, serum C-3 levels in pre-and post-CM incubation samples were determined by a rocket technique. No consumption of the complement protein C-3 or split products of C-3 were seen in counter immunoelectrophoresis. These studies indicate that P-297 possesses mild anticoagulant and complement activating actions, and seems relatively safer than other ionic forms of CM. Furthermore, our studies suggest that non-ionic contrast agents produce minimal effects on coagulation and complement systems and can be used without much risk to patients with pre-existing coagulation and/or complement disorders.
An Assessment Of An Amidolytic Assay For Factor VII In The Laboratory Control Of Oral Anticoagulants
Authors: Bodzenta A , Thomson Jean M , Latallo Z S
Published: July 2018

An amidolytic assay for factor VII, modified from the method of Seligsohn et al (1978), has been compared with the results of the prothrombin time using British Comparative Thromboplastin, Thronbotest and a clotting assay for factor VII. In ‘long-term’ oral anticoagulant administration agreement with the conventional methods was good and better than in our previous study when amidolytic assays for factors II and X respectively were studied (Latallo et al 1981). The method appeared to be reasonably specific for factor VII.

On the present evidence the chromogenic assay for factor VII offers a limited but apparently dependable guide to dosage but it is elaborate to perform and difficult to standardise. The main limiting factor for its routine application is the need to prepare a purified factor X extract.
Determination Of Thrombo Elastogram And Raby’S Transfer Test In Acute Myocardial Infarction
Authors: Rodzynek J J , Schoenfeld P L , Léautaud P , Martin T , Wettendorff P , Delcourt A
Published: July 2018

Citrated whole blood thrombo elastogram (TEG) and its various parameters (r, k, am, IPT) and Raby’s transfer test (RTT) were performed in 52 healthy volunteers acting as normal controls (N), in 213 consecutive patients admitted in a general hospital for pathologies other than cardiac ischemia (group I), in 35 consecutive admissions for impending infarction without detectable myocardial necrosis (group II) and in 73 consecutive admissions for acute myocardial infarction, proved by EKG and specific enzyme determinations (group III).

In conclusion: TEG is a poorly sensitive as well as poor specific indicator of unstable coronary insufficiency, with or without necrosis. RTT was found positive in 8.5% of unstable angina without demonstable myocardial necrosis, and in contrast in 94.5% of demonstrated acute myocardial infarction. Student’s test on mean values showed a highly significant difference (P<0.001). Further investigation is in progress to evaluate the usefulness of RTT for the early detection of myocardial necrosis.
Antithrombin III In Chronic Liver Diseases
Authors: Rak K , Boda Z , Misz M , Beck P
Published: July 2018

One of the most constant abnormal laboratory results in chronic liver diseases is the low antithrombin III /AT-III/ acitivity measured in a properly sensitive system. Two functional assays have been used in our laboratory: /a/ coagulation test based on the progressive neutralization of thrombin with clotting time determinations in the presence of small amount of heparin and without it; results were expressed as plasma AT-III index or PAT-value, and /b/ amidolytic method on synthetic chromogenic substrate.

Results of the last years can be summarized as follows: /1/ the measurement of AT-III in liver diseases/more than 300 cases, mostly cirrhosis/ is of diagnostic significance: a high index, hence a low AT-III activity, particularly in a system containing heparinized plasma is much more characteristic in cases of liver cirrhosis than results of other conventional clotting tests /prothrombin time, partial thromboplastin time, plasma fibrinogen and FDP level/; /2/ the observations may have theoretical importance, furnishing additional data on the pathophysiological role of AT-III and providing the first and strong evidence for the adverse effect of heparin in thrombin-antithrombin interaction. The level of this natural anticoagulant synthetized in liver may be reduced by increased consumption accompanying disseminated intravascular coagulation. Though it is not frequent, it must be taken into consideration, first of all in active chronic hepatitis.
AT-III Diagnostic And Prognostic Value In Hepatic Disease
Authors: Monreal M , Rodriguez R , Vañentin P , Monasterio J
Published: July 2018

AT-III activity has been evaluated in 675 patients with different kinds of hepatic disease.

In 300 patients with hepatic chronic disease, AT-III levels showed a good correlation with prothrombin time as well as same diagnostic value. Survival in this group of patients was directly related to AT-III values.

In 75 patients with acute liver disease, persistent low AT-III values correlated with clinical evolution of fulminans hepatitis.

In 200 patients with cholestatic syndrome, evaluation of AT-III levels had no value for differential diagnosis of neither obstacle’s localization nor benign or neoplastic process.

In 100 patients, suffering from cancer, without and with hepatic metastasis, AT-III values decreased in terminal states only.
Increased Anti-Xa Bioavailability Of Heparin By Jet Injection
Authors: Arleth D , Harenberg J , Mattes K , Zimmermann R
Published: July 2018

To improve the standardisation and to diminish the time requirement of the subcutaneous (s.c.) application of low dose heparin a semiautomatic injection pistol was compared to the commonly used one way syringe.

The precision of the injected amount of heparin was significantly higher by jet injection (VK 1% vs 4%). The time required for one injection was 110 sec by jet injection and 215 sec by the one way syringe including all preparation times.

7500 USP heparin were injected into 10 volunteers by both techniques at weekly intervals randomly. The pharmacodynamic effects were controlled on the factor Ila activity (thrombin clotting time), aPTT and factor Xa activity (chromogenic substrate S2222) for 10 hrs by 12 blood samples. No differences were observed on the factor IIa activity and aPTT between the two injection techniques. The anti- Xa-activity of the heparin applicated by jet injection was significantly higher (maximal effect after 3 hrs: 0.24 vs 0.20 USP heparin/ml plasma, p < 0.01, area under the time related curve p < 0.01).

The data indicate, that the bioavailability of heparin for factor Xa is even higher after the s.c. application by the jet injection method than after the one way syringe technique. These differences should be considered, when an improvement of the prophylaxis of thromboembolic diseases is discussed.
The Clinical Importance Of Heparin Assays In Plasma. Critical Aspects In Antixa Techniques
Authors: Giuliani R , Szwarcer E , Aquino E Martinez
Published: July 2018

Different clotting assays for heparin measurement in plasma, based on AntiXa potentiating effect were studied, to determine the causes of variability in results in the currently used techniques. A modified 2 steps technique was also used (step I:0.1ml test plasma (PPP)+0.3ml buffer+0.1 mlXa.2' incubation at 37°C:step II: 0.1ml of step I mixtu- re+0.2ml of substrate plasma+CaCl 0.1ml. (Xa and VII-X defficitary bo vine plasma+cefalin: Thame, Oxon. Triz-Mal buffer,ionic strength 0.15, PH7.5 and CaCl 0.025M). Three modifications of the technique were used, varying test plasma treatment: a) using oxalated PPP, adsorbed with BaS04 b) like in a) plus heating it at 56°C 15'; c)using untreated plasma.

Using a) assay (K dependant factors absent), straight regression lines and low variability of results was obtained, relating heparin concentrations to clotting times;usinga b) it was seen that heat diminishes AntiXa reactivity to hepa- riny using c)high variability in results was obtained. To show the difficulties in monitoring heparin in cases where Iox AntiXa concentrations, variable amounts of clotting factors and differents amounts of heparin might be present, a pool of normal plasmas, a normal plasma, and a cirrhotic one were compared, using the modified AntiXa assay in its 3 variations. Wide differences in results may be obtained while studying the cirrhotic plasma, using techniques that can vary AntiXa reactivity, or mask the real heparin in plasma, because of its variable content in K dependant factors.

We did not find a way of clearing test plasma of K dependant factors when heparin is in it without altering heparin concentration or AntiXa reactivity.

Thus, it is suggested, for clinical monitoring of the drug to use heated or untreated plasma, and to compare results with the same individuals plasma, studied under equal conditions, and not with a pool of normal plasmas, as common ly suggested.
Platelet Adhesion to Collagen Is Inhibited by Adenosine Diphosphate but Unaffected by Cell Shape
Authors: Meyer F A , Weisman Z , Frojmovic M M
Published: July 2018

The effect of limited platelet activation, in the absence of aggregation, on the subsequent ability of rabbit platelets to adhere to collagen was studied in vitro. ADP at concentrations that initiate shape change (>0.01. μM) reduce platelet adhesion. Shape change per se however, was not responsible since the time-dependence of the effect of ADP on shape change and adhesion is different and ADP induces reduced adhesion even when shape change is prevented with PGE1 or fixatives. Platelets shape changed without ADP addition, e. g. by chilling or by low ethanol concentrations, display normal adhesion to collagen

It appears likely that upon binding to the platelet ADP induces a time-dependent alteration in the membrane, akin to refractoriness, that influences binding sites for collagen. The effect of ADP can be blocked by prior addition of AMP but not if the additions are reversed. The implications of the present findings for platelet adhesion studies are discussed.
Factor VIII : C and Factor VIII R: Ag in Argentine Hemorrhagic Fever
Authors: Molinas Felisa C , Maiztegui Julio I
Published: July 2018

Factor VIII procoagulant activity (F VIII: C) and factor VIII related antigen (F VIII R: Ag) were investigated in 35 patients with Argentine hemorrhagic fever. Since the results obtained in the three clinical forms of the disease were not significantly different, they were tabulated altogether. F VIII: C was low in early stages of the disease but increased progressively in later days (days 5–6:0.54 ± 0.10 I.U./ml; days 13–14:0.95 ± 0.13 I.U./ml). In contrst, the levels of F VIII R: Ag were high all along the disease and they returned to normal values during the convalescence period (days 5–6; 2.58 ± 0.54 I.U./ml; day 30: 1.30 ± 0.14 I.U./ml). The levels of F VIII R: Ag were similar in samples drawn before (11 cases) or after (10 cases) the treatment with immune plasma infusion. Plasma samples from 12 patients were studied by two-dimensional immunelectrophoresis. The only abnormality found was increased height of the immune precipitation arc.
Prolonged Thromboprophylaxis Following Hip Replacement Surgery – Results of a Double-blind, Prospective, Randomised, Placebo-controlled Study with Dalteparin (Fragmin®)
Authors: Dahl O E , Andreassen G , Aspelin T , Müller C , Mathiesen P , Nyhus S , Abdelnoor M , Solhaug J-H , Arnesen H
Published: July 2018

Discontinuation of thromboprophylaxis a few days after surgery may unmask delayed hypercoagulability and contribute to late formation of deep venous thrombosis (DVT). To investigate whether thromboprophylaxis should be prolonged beyond the hospital stay, a prospective, double-blind randomised study was conducted in 308 patients. All patients received initial thromboprophylaxis with dalteparin, dextran and graded elastic stockings. On day 7, patients were randomised to receive dalteparin (Fragmin®) 5000IU once daily, or placebo, for 4 weeks. All patients were subjected to bilateral venography, perfusion ventilation scintigraphy and chest X-ray on days 7 and 35. Patients with venographically verified proximal DVT on day 7 were withdrawn from the randomised study to receive anticoagulant treatment. The overall prevalence of DVT on day 7 was 15.9%. On day 35, the prevalence of DVT was 31.7% in placebo-treated patients compared with 19.3% in dalteparin-treated patients (p = 0.034). The incidence of DVT from day 7 to day 35 was 25.8% in the placebo-treated group versus 11.8% in the dalteparin-treated group (p = 0.017). The incidence of symptomatic pulmonary embolism (PE) from day 7 to day 35 was 2.8% in the placebo-treated group compared with zero in the dalteparin-treated group. This included one patient who died from PE. No patients experienced serious complications related to the injections of dalteparin or placebo. This study shows that prolonged thromboprophylaxis with dalteparin, 5000 IU, once daily for 35 days significantly reduces the frequency of DVT and should be recommended for 5 weeks after hip replacement surgery.
In Vitro Clot Lysis as a Potential Indicator of Thrombus Resistance to Fibrinolysis – Study in Healthy Subjects and Correlation with Blood Fibrinolytic Parameters
Authors: Colucci Mario , Scopece Silvia , Gelato Antonio V , Dimonte Donato , Semeraro Nicola
Published: July 2018

Using an in vitro model of clot lysis, the individual response to a pharmacological concentration of recombinant tissue plasminogen activator (rt-PA) and the influence on this response of the physiological variations of blood parameters known to interfere with the fibrinolytic/thrombolytic process were investigated in 103 healthy donors. 125I-fibrin labelled blood clots were submersed in autologous plasma, supplemented with 500 ng/ml of rt-PA or solvent, and the degree of lysis was determined after 3 h of incubation at 37° C. Baseline plasma levels of t-PA, plasminogen activator inhibitor 1 (PAI-1), plasminogen, α2-anti-plasmin, fibrinogen, lipoprotein (a), thrombomodulin and von Willebrand factor as well as platelet and leukocyte count and clot retraction were also determined in each donor. rt-PA-induced clot lysis varied over a wide range (28-75%) and was significantly related to endogenous t-PA, PAI-1, plasminogen (p <0.001) and age (p <0.01). Multivariate analysis indicated that both PAI-1 antigen and plasminogen independently predicted low response to rt-PA. Surprisingly, however, not only PAI-1 but also plasminogen was negatively correlated with rt-PA-ginduced clot lysis. The observation that neutralization of PAI-1 by specific antibodies, both in plasma and within the clot, did not potentiate clot lysis indicates that the inhibitor, including the platelet-derived form, is insufficient to attenuate the thrombolytic activity of a pharmacological concentration of rt-PA and that its elevation, similarly to the elevation of plasminogen, is not the cause of clot resistance but rather a coincident finding. It is concluded that the in vitro response of blood clots to rt-PA is poorly influenced by the physiological variations of the examined parameters and that factors other than those evaluated in this study interfere with clot dissolution by rt-PA. In vitro clot lysis test might help to identify patients who may be resistant to thrombolytic therapy.
Erythropoietin Potentiates Thrombus Development in a Canine Arterio-Venous Shunt Model
Authors: Wolf Roman F , Gilmore Laura S , Friese Paul , Downs Tamyra , Burstein Samuel A , Dale George L
Published: July 2018

Erythropoietin (EPO) has been previously shown to affect platelet as well as red cell production. In addition, recent studies demonstrated that platelets from EPO-treated dogs are hyperreactive towards thrombin when compared to age-matched, control platelets. This report extends these observations by quantitating the thrombogenic potential of EPO in dogs. Dogs with arterio-venous (A-V) shunts received 100 U EPO/kg/day for 6 days, and thrombogenicity was serially monitored by insertion of a thrombotic surface into the A-V shunt. The resulting experimental thrombi were analyzed for platelet and erythrocyte content after formalin-fixation and chymotrypsin digestion, a technique which allows non-isotopic quantitation of cellular components. By day 5 of EPO-administration all animals demonstrated a significant increase in platelet and red cell content of the experimental thrombi; the average increase in platelet number was 2.94 ±0.12 fold (mean ± 1 SE; n = 3; p = 0.006) above baseline while that for red cells was 2.46 ±0.18 fold above baseline (p = 0.023). After cessation of EPO, thrombogenicity returned to normal. During EPO-treatment, the percentage of thiazole orange-positive (TO+) platelets increased significantly to 17.2 ± 1.6% (mean ± 1 SE; n = 3) on day 5 compared to a pre-treatment level of 8.5 ± 0.9% (p = 0.029). Although the percentage of TO+ erythrocytes also increased during the short course of EPO administration, the change was not significant. Despite the increases in TO+ cells, total platelet and erythrocyte counts did not change significantly within the time frame of these experiments. Fibrin/fibrinogen content of the experimental thrombi was unaltered with EPO-treatment. These data demonstrate that human EPO is pro-thrombotic in dogs and, in conjunction with earlier studies, suggest that hyperreactive platelets may be responsible for the potentiated thrombogenicity.
Factor XIII Deficiency due to a Leu660Pro Mutation in the Factor XIII Subunit-a Gene in Three Unrelated Palestinian Arab Families
Authors: Inbal Aida , Yee Vivien C , Kornbrot Nurit , Zivelin Ariella , Brenner Benjamin , Seligsohn Uri
Published: July 2018

In this report we describe the molecular basis of FXIII a-subunit deficiency in three unrelated Palestinian Arab families. In three patients representing each family two substitutions were identified in exon 14 on both alleles: C to G change resulting in a Gln651Glu substitution (a previously described polymorphism) and a T to C transition causing Leu660Pro substitution. The latter is a new mutation which creates a restriction site for FnuDII enzyme. Restriction analysis performed in members of the three families clearly distinguished between severely affected patients, obligate carriers and unaffected subjects. A population survey failed to detect the mutation among 250 Jewish individuals but did detect two heterozygotes among 300 Arabs suggesting a 0.0033 frequency for the Pro660 allele in this population. In two out of the three families the Pro660 allele was linked to allele 5 of the 5’ short tandem repeat polymorphism within the FXIII a-subunit gene suggesting that the mutation might have occurred at least twice. cDNA obtained from mRNA isolated from patients’ platelets and monocytes appeared similar in size to that of normal control indicating that the Leu660Pro mutation does not affect mRNA synthesis. Computer modeling based on cristallographic studies of the a-subunit of factor XIII predicted that the mutant protein is expected to misfold into a structure which is either unstable or susceptible to degradation.
The Stability of Factor VIII in Heparinized Plasma
Authors: Krachmalnicoff A , Thomas D P
Published: July 2018

We studied the stability for 24 hr of factor VIII: C and factor Vm C:Ag in plasma collected in citrate, EDTA or heparin, and confirmed the previously reported two-phase decay of factor VIII:C in plasma when calcium ions have been chelated. We observed that plasma factor VIII:C is remarkably stable at 22° C (±2°) when normal calcium ion concentrations are maintained. The loss of activity of factor VIII:C between one and 24 hr after blood collection was on average only 0.5% per hr for heparinized plasma. There was also an apparent loss of factor VIII C:Ag in plasma where calcium ions had been removed, compared with factor VIII C:Ag in heparinized plasma. However, a comparison of one-site and two-site assays suggested that calcium chelating agents may lead to factor VIII C:Ag levels being under-estimated when one-site fluid-phase assays are employed.

To confirm the action of calcium ions in maintaining factor VIII:C stability, we carried out a series of experiments where calcium chloride was added four hr after blood collection to plasma anticoagulated by a mixture of citrate plus heparin; we observed total recovery of factor VIII:C activity within four hr.

The stability of factor VIII:C, even at room temperature, in the presence of physiological calcium ion concentrations has implications for manufacturers of factor VIH concentrates and cryo-precipitates.
Direct Analysis of Plasma Fibrinogen-Derived Fibrinopeptides by High Performance Liquid Chromatography: Investigation of Aα-Chain N-Terminal Heterogeneity
Authors: Southan Christopher , Thompson Elizabeth , Lane David A
Published: July 2018

Fibrinopeptide A (FPA), released from the fibrinogen Aa-chain by thrombin, can be resolved by high-performance liquid chromatography (HPLC) into three forms, the intact peptide (A), a modified peptide phosphorylated at the serine in position 3 (AP), and an N-terminally degraded form (AY). A new method has been developed, using HPLC, that allows direct measurement of the proportions of AP, A, and AY released by thrombin from fibrinogen in plasma samples of 200 ul or less. The method was used to examine variations in the proportions of AP and AY expressed as a % of total FPA in a number of patient and control groups. The mean percentages of AP and AY of plasma fibrinogen were found to be 21.7 and 14.2%, respectively, in normal laboratory controls. In older, apparently normal, individuals these figures were 27.0 and 15.5%, respectively. Cord plasma exhibited very high AP and slightly reduced AY levels (41.6 and 12.4%, respectively) compared with normal adults. Patients with liver failure had low AP levels and high AY levels (11.6 and 21.1%, respectively). Patients, recovering from major surgery or acute thrombotic stroke showed an acute-phase rise in fibrinogen level that was accompanied by an increase in AP and variable reduction in AY. Incubation of heparinized whole blood for 8 days in vitro demonstrated a gradual decrease in the proportion of AP and increase in AY of plasma fibrinogen. These results provide some support for the idea that an increased “aging” of fibrinogen in the circulation may result in a decrease in the AP content of fibrinogen accompanied by a more variable increase in AY.
Spectral symmetry breaking of electro-acoustic noise in ferroelectric materials
Authors: Sinha Dhiraj
Published: July 2018

We present a novel analytical formulation on generation of electro-acoustic noise in ferroelectric materials where the thermal fluctuation induced polarization and acoustic modes distinctly contribute to noise. The conservative force fields associated with ferroelectric materials drive feedback of the spectral modes in the system. It results in symmetry breaking of the frequency spectrum of broadband noise, leading to enhancement of specific modes which generate high amplitude narrowband noise. We describe the process under the theoretical framework of fluctuation-dissipation theorem in the context of ferroelectric materials. We further note that such spectral feedback is absent in Johnson-Nyquist noise generation in conductors which have spectral symmetry.
Crystalline SrZrO3 deposition on Ge (001) by atomic layer deposition for high-k dielectric applications
Authors: Hu Shen , Ji Li , Chen Pei-Yu , Edmondson Bryce I. , Chang Heng-Lu , Posadas Agham , Wu Hsin Wei , Yu Edward T. , Smith David J. , Demkov Alexander A. , Ekerdt John G.
Published: July 2018

Heteroepitaxial growth of crystalline SrZrO3 (SZO) on Ge (001) by atomic layer deposition is reported. Ge (001) surfaces are pretreated with 0.5-monolayers (ML) of Ba and an amorphous ∼3-nm SZO layer is grown from strontium bis(triisopropylcyclopentadienyl), tetrakis (dimethylamido) zirconium, and water at 225 °C. This ∼3-nm layer crystallizes at 590 °C and subsequent SZO growth at 225 °C leads to crystalline films that do not require further annealing. The film properties are investigated using X-ray photoelectron spectroscopy, x-ray diffraction, aberration-corrected electron microscopy, and capacitance-voltage measurements of metal-oxide semiconductor capacitor structures. Capacitance-voltage measurements of the SrZrO3/Ge heterojunctions reveal a dielectric constant of 30 for SrZrO3 and a leakage current density of 2.1 × 10−8 A/cm2 at 1 MV/cm with an equivalent oxide thickness of 0.8 nm. Oxygen plasma pretreatment of Ge (001), Zintl layer formation with 0.5 ML Ba, and atomic deuterium post-growth treatment were explored to lower interface trap density (Dit) and achieved a Dit of 8.56 × 1011 cm−2 eV−1.