bluuebunny/crossref_metadata_2025 huggingface dataset:
Lysis of Crosslinked and Non-Crosslinked Purified Fibrin
Authors: Haverkate F.
Published: June 2019

Several authors have reported that cross-linking by Factor XIII makes fibrin less susceptible to lysis by fibrinolytic enzymes, especially to plasminogen activators. However, the conclusions of most of these studies have been based on circumstantial evidence.

To unambiguously establish a possible effect of cross-linking of fibrin on its resistance to lysis, the following experimental conditions are necessary (a) the use of preformed fibrin substrate, (b) the use of purified protein components, and (c) measurement of the extent of cross-linking. With due observance of these conditions, we determined lysis of both cross-linked and non cross-linked fibrin by plasmin, urokinase, and a human tissue activator by means of the fibrin plate assay. Purified preparations of fibrin, F XIII, and plasminogen were used. Cross-linking was determined by means of SDS polyacrylamide gel electrophoresis.

The results revealed no differences in resistance to lysis of highly cross-linked and non-cross-linked fibrin.

They suggest that the mechanism underlying the effect of F XIII on haemostasis is not directly related to a change in the resistance of the fibrin in the blood clot to lysis by fibrinolytic enzymes. For a better understanding of the role of F XIII in haemostasis, attention should be focused on processes which occur in the whole blood clot and not in purified fibrin.
Coagulation and Fibrinolytic Changes in Aortic Graft Operations
Authors: Phillips L. L. , Mulcare R. J. , Royster T. S.
Published: June 2019

A finding of intravascular coagulation (DIC) and renal shutdown in 7 patients undergoing repair of abdominal aortic aneurysms (AAA) led to a study of all aortic graft operations over a 14 month period. Coagulation studies were performed pre-operatively, immediately post-op, and at 24 hours on 32 patients undergoing aortic replacement with synthetic grafts. 18 patients had AAA and 14 had aorto-iliac occlusive disease. No differences were found in the two groups, therefore results were pooled for statistical purposes. In both post-op periods significant differences were found from mean pre-op levels in prothrombin time, platelets, plasminogen, fibrinolytic inhibitors, fibrin monomer, and fibrin/fibrinogen split products (FSP) by a method using anti-D and E coated latex particles. Fibrinogen was significantly decreased only in the immediate post-op period while the partial thromboplastin time was increased at 24 hours. Anti-fibrinogen coated latex particles showed no changes in FSP. 10% of patients showed positive fibrin monomers pre-op but this increased to 55% immediately post-op and 27% in 24 hours. FSP (D & E) of 10 μg/ml or greater were found in 25% of patients pre-op and over 60% in the post-op periods. While only two patients had mild clinical evidence of DIC which was treated with heparin (5 units/kg/hr), the results suggest that such graft procedures may initiate low grade intravascular coagulation which under most circumstances is offset by an activation of the fibrinolytic system.
Arterial Thromboembolism and Prosthetic Heart Valves. Effects of Acetylsalicylic Acid
Authors: Dale J. , Myhre E. , Storstein O. , Stormorken H.
Published: June 2019

Prevention of arterial thromboembolism with acetylsalicylic acid (ASA) was studied double-blind in patients with aortic ball valve prostheses. Such patients have a high incidence of arterial emboli originating from thrombi formed on the valves, and the clinical effects of antithrombotic drugs can better be studied in this condition than in myocardial infarction, where the role of thrombosis is not definitely settled.

A total of 156 patients with single Starr-Edwards aortic ball valves received either one gm. of ASA daily or placebo in combination with warfarin, and were observed for two years. Only two emboli were diagnosed in patients taking ASA, none of them severe. In the placebo group 12 thromboembolic episodes occurred in 10 patients, and three with cerebral emboli died. Gastrointestinal complications were seen more frequently in patients receiving ASA, while two persons in each group suffered from intracranial bleeding. It was concluded that ASA combined with anticoagulants offered a significantly better protection against arterial thromboembolic complications than did anticoagulant therapy alone.
The Arterial Wall after Pulmonary Embolism
Authors: Sevitt S.
Published: June 2019

Little has been reported on the effects of emboli on lung arteries. This report is based on 93 subjects reaching necropsy with emboli, of which 223 were studied histologically.

Arterial lesions which can be regarded as traumatic from embolic impact are: (1) Partial or complete ruptures of the wall, mostly narrow slits but a few larger. Recent ones were associated with recent emboli, and healing tears with organising emboli. (2) Micro-aneurysms frequently associated with ruptures. (3) Small scars associated with fibrous remnants of emboli, and consistent with previous ruptures. (4) Focal necrosis and/or focal arteritis.

Lesions allied to atheroma developing during organic reduction of the emboli are: (5) Fatty infiltration of the intima; (6) Incorporation of hyalinized thrombus into thickened intima; (7) occasionally patchy calcification.

Sequelae from organic reduction of emboli are fibrous intimal thickenings, networks, webs and cords, and fibrous occlusion of the lumen.
Canine Renal Allograft Rejection: Evaluation of Progressive Microsvacular Thrombosis
Authors: Webster W. P. , Mandel S. R. , Staab E. V. , Clark R. L.
Published: June 2019

Microvascular thrombosis is the end stage of the rejection process. Twenty paired dogs receiving heterotopic renal allografts were monitored with serial orthiodohippuronic acid 131I (OIH) renoscintigrams, intravenous pyelograms (IVP), and coagulation parameters, and were sacrificed at various intervals. Microangiograms and histological sections of the transplanted and normal kidneys were obtained. Results of the IVP and OIH studies were somewhat parallel, but the OIH identified very early parenchymal damage that was not detected with the IVP. Additionally, the OIH demonstrated remaining function that could not be identified with the IVP. Microvascular and histological changes progressed from the outer cortex inward. Early findings were focal cortical capillary occlusion with perivascular cellular infiltration. Late changes included outer cortical glomerular loss and afferent arteriolar occlusions that progressed to interlobular arteriolar obstruction. Arteriolar-venule shunting and vascular extravasation were evident. Histologically there was marked cellular infiltration and hemorrhagic necrosis. Coagulation changes consisting of increases in plasma levels of fibrin split products (FSP), F. VIII and fibrinogen were evident in the late stages, and consistent with progressive localized intravascular thrombosis. This study demonstrates and correlates the progressive stages of microvascular thrombosis induced secondary to antigen-antibody induced injury. The OIH is a sensitive in vivo test, and FSP are reliable indicators of late vascular damage.

(Supported in part by the National Heart and Lung Institute Grant HL-14228.)
Purification of Ristocetin Willebrand Factor (RWF)
Authors: Olson J. D. , Fass D. N. , Brockway W. J. , Bowie E. J. W. , Mann K. G.
Published: June 2019

A component required for the ristocetin-induced aggregation of platelets was isolated in yields of 20-30% from pooled human and porcine plasma by cryoethanol concentration of the RWF, after removal of the vitamin K dependent coagulation factors on barium citrate. The concentrate was further purified using gel filtration (4% agarose) and ion exchange (DEAE-cellulose) chromatography. Sodium dodecyl sulfate polyacrylamide gels of the isolated factor indicated an apparent molecular weight of greater than 500,000. After reduction of RWF with mercaptoethanol, a single band is resolved with an apparent molecular weight of 230,000. The purified component had no factor VIII procoagulant activity and did not compete for the activity of naturally occurring factor VIII inhibitor (human). Antisera raised in rabbits directed against the purified component inhibited the RWF activity but not the factor VIII procoagulant activity of plasma. Amino acid analysis indicated the presence of all normal amino acids and failed to detect any amino sugar. Analysis of lipid revealed a significant amount of lipid composed of mono, di and triglycerides, cholesterol, cholesterol esters and free fatty acid, with small portions of phospholipids.
Disappearance of Canine Small Active Factor VIII Fragment Following Transfusion in Hemophilic Dogs
Authors: Attain J. P. , Cooper H. A. , Wagner R. H.
Published: June 2019

Small active factor VIII fragment was prepared for infusion studies by agarose gel chromatography of a canine factor VIII preparation in 0.25 M CaCl2. The material was concentrated, and the Ca2+ was removed. Three hemophilic dogs received four infusions of 13 to 30 u of factor VIII activity per kg of body weight. Immediate recovery of factor VIII activity varied from 0 to 25% of the calculated values. Most of the activity disappeared within two hours after infusion, but whole blood clotting times were still shortened after 12 hours in two experiments. Control studies using cryoprecipitate were satisfactory. Plasmas of three of six hemophilic dogs showed weak inhibition of the small active factor VIII fraction in vitro. The inhibitory effect was present in these hemophilic plasmas after heating to 56° C for 1 hour. The rapid disappearance of activity after transfusion is not completely explained by this inhibitory effect, as rapid in vivo disappearance was also observed where no inhibition was detectable. It appears that use of small active factor VIII does not offer a practical means for intravenous, subcutaneous, or intramuscular administration.

(Supported by NIH Grants HL-6350, HL-1648).
Prognostic Value of Factor VIII in Glomerulonephritis
Authors: Ekberg M. , Nilsson I. M. , Hedner U.
Published: June 2019

Factor VIII and factor VIII related antigen were determined in 116 patients with early glomerulonephritis (< 6 months duration) without impairment of renal function. Other coagulation and fibrinolytic components and acute phase reactants were also determined. The patients were followed for up to four years with respect to both coagulation pattern and renal function. It was found that the values for factor VIII and factor VIII related antigen were initially normal in those who made a complete recovery during follow-up but high in those who developed persistent renal damage. The other coagulation factors and the acute phase reactants were of no prognostic significance. Factor VIII related antigen has been shown to be synthetised in the vessel intima. The initial factor VII level in early glomerulonephritis may reflect the degree of vascular engagement of the glomeruli. The high factor VIII levels, especially factor VIII related antigen, may be of significance in the development of fibrin deposits in glomeruli.
Platelet Function in Various Haemorrhagic Disorders
Authors: Mandalaki T. , Dimitriadou C.
Published: June 2019

Platelet aggregation by ADP, collagen, thrombin and ristocetin was studied systematically both in citrate platelet rich plasma and isolated platelets by density gradient using albumine (according to Nicholls and Hampton) in various cases of congenital haemorrhagic diathesis, namely v. Willebrand disease, Glanzmann disease (thrombasthenia), Thrombopathy (PF3, defect), Factor XIII deficiency and in unclassified hereditary haemorrhagic disorders as well as in acquired bleeding tendency. According to the platelet abnormalities found during this study a classification of “Thrombopathies” observed in Greece is attempted.
Effect of Emotional Stress on Platelet Function in Humans
Authors: Haft J. T. , Arkel Y. S.
Published: June 2019

Emotional stress is one of the important risk factors associated with coronary atherosclerosis and acute myocardial infarction. The initial event in the formation of an atherosclerotic plaque may be a mural platelet aggregate forming on the endothelial surface of an artery; and the final event in myocardial infarction may be the plugging of a narrowed area of a coronary vessel by an inappropriately forming intravascular platelet aggregate. To study the effect of emotional stress on platelet function, 14 normal interns and residents were studied immediately before, immediately after, and 7 days after presenting a case before a large critical group of attending physicians. Response of platelet rich plasma to ADP and epinephrine was determined using a Chronolog aggregometer. In eleven subjects the rate of first phase aggregation, the percent total aggregation and the length of the plateau phase with epinephrine indicated significantly inhibited platelet function immediately after stress as compared to the baseline study 7 days later. Eight subjects responded similarly to ADP. In 4 subjects similarly decreased function occurred in the prestress (anticipation) period. It is concluded that emotional stress has a profound effect on platelet function, an effect that may suggest that platelets aggregate intra-vascularly during stress, deaggregate, and then are relatively insensitive to aggregation immediately after the stress period.
Activation of Hageman Factor in Rat Anaphylaxis
Authors: Fésüs L. , Muszbek L.
Published: June 2019

At various intervals after antigen injection assays concerning haemostatic parameters were carried out in anaphylactic shock of rats pretreated with Bordetella Pertussis Vaccine. These were as follows: measurement of whole blood clotting time, recalcification time, partial thromboplastin time, kaolin clotting time in siliconised tubes, determination of the level of factor XII, measurement of plasminogen activator level, in vitro aggregation of platelets. The different clotting times shortened and the aggregation of platelets was inhibited within the first three-four minutes. The clotting times lengthened, the level of plasminogen activators increased, the level of factor XII decreased during the further minutes. These results and their comparison with that of produced by ellagic acid injection suggest that during anaphylaxis of rats the activation of Hageman factor takes place, which is followed by its partial consumption.
Modification of Venous Stasis Thrombosis by Platelet Active Drugs and by Heparin
Authors: De Clerck F. , Vermijlen J. , Hornstra O. , Reneman R.
Published: June 2019

In rats, stasis thrombosis of a renal vein was produced by the occlusion of a vascular segment after the induction of systemic hypercoagulability by intravenous injection of ellagic acid. The development of thrombosis depended upon the dose of ellagic acid, the duration of circulation before occlusion of the vascular segment and the duration of stasis. Morphologically the thrombus consisted mainly of red blood cells with occasional foci of platelet aggregates. Prostaglandin El, at doses which reduced platelet retention by glass beads (6 μg/min/300 g I.V.) only slightly reduced thrombus size. The platelet release inhibitor indomethacin (50 mg/kg I.V.) had no effect on thrombus size. Heparin (10 and 20 u/kg I.V.) produced a dose-related reduction of venous thrombosis. The platelet-active drug VK 774 at l0 to 50 mg/kg I.V. also reduced the thrombus size. Binding to ellagic acid or induction of coagulation changes are proposed as a possible mechanism of action. It is concluded that the participation of platelet function in the development of venous stasis thrombosis is small.
Influence of Steroids on Endotoxin Induced Disseminated Intravascular Coagulation
Authors: Beller F. K. , Ribhegge J. , Schmidt E. H.
Published: June 2019

We have previously demonstrated that stilbestrol augments disseminated intravascular coagulation (Theiss, W., Beller, F. K. Amer. J. Obstetr. Gynee., 115, 795, 1973). This was demonstrated by using a standardized endotoxin infusion model in rats. The experiments were repeated systematically on castrated females. Different groups of about 20 rats got daily injections of ethinyl oestradiol, progesteron or a combination of both over a period of three weeks. It was shown that ethinyl-oestradiol augmented DIC in a dose range of 30 μg, whereas pre treatment with oestrogen in smaller doses or with progesteron or both was not so effective. In contrast to these findings pretreatment with corticosteroids in a large dose range prevented glomerular fibrin deposits completely.
Studies on a Variant of Factor VIII Resulting in ’von Willebrand’s Disease»
Authors: Hill F. G. H. , Chan M. C. K. , Hardisty R. M.
Published: June 2019

A variant of von Willebrand’s disease in a 14-year-old girl is described, characterised by a prolonged bleeding time and defective ristocetin aggregation (VIIIWF 6%), with VIIIRAg 70-110% and VIIIC 40-60%. The electrophorotic mobility of her VIIIRAg in agarose at pH 9.2 was intermediate between normal VIIIRAg and that of the patient of Kernoff et al, (1), and identical with that of Case 4 of Peake et al. (2). Further characteristics of the factor VIII molecule in this patient’s plasma and platelets will be presented, including antigenic, physicochemical and functional propeertis.

1. Kernoff, P. B. A. et al. (1974). Brit. J. Haemat. 26, 435.

2. Peake, I. R. et al. (1974). N. Engl. J. Med. 291, 113.
Effect of Neutral Proteases of Human Granulocytes on Isolated Clotting-Factors
Authors: Schmidt W. , Egbring R. , Havemann K. , Beeser H.
Published: June 2019

To examine whether direct proteolysis of coagulation factors may play a role in patients with so called consumption coagulopathy, an elastase-like and a chymotrypsin-like neutral protease isolated from human granulocytes were investigated for their influence on several purified clotting factors. The elastaselike protease induced a rapid destruction of fibrinogen, factors II, VIII, XII and XIII activity, whereas a moderate effect on factor V and VII activity was observed. The chymotrypsin-like enzyme showed a rapid inactivation of factor VIII, moderate effect on factor VII and XIII and only a weak activity against fibrinogen, factor II and XIII. Incubation of factor V with both enzymes leads to a transitory activation. In spite of the presence of a high antiprotease potential in plasma, addition of the elastase-like enzyme to normal plasma resulted in an activation of several coagulation factors. As it has been shown that the proteases are activity released from granulocytes in presence of antigen-antibody complexes, endotoxin and polynucleotides, the results given above together with the appearence of granulocytic proteases in the plasma of patients with acute leucemia and septicemia suggest that in certain types of coagulation factor deficiencies direct proteolysis rather than consumption of clotting factors due to dissiminated intravascular coagulation may be operational.
Antithrombotic Effect of Sulfinpyrazone in Arterio-venous Shunts
Authors: Pineo G. , Kaegi A. , Hirsh J. , Gent M. , Moore S.
Published: June 2019

The arterio-venous shunt provides an ideal model for studying the antithrombotic effects of drugs which suppress platelet function because the incidence of thrombosis is high and the thrombi occur in areas of high flow, turbulence and venous stenosis. We have investigated 1) the antithrombotic effectiveness of Sulfinpyrazone (SFP) 600 mg daily in a 12 month double blind crossover study as compared to a placebo 2) the relative efficacy of SFP alone as compared to SFP plus an oral anticoagulant and 3) the nature of the histological changes Which underlie the thrombotic occlusion in the vein adjacent to the cannula.

1) In the first study there were 45 patients. The average number of thrombi per patient month was 0.21 on SFP compared to 0.64 on the placebo (p < 0.001). The antithrombotic effect was more striking in men than in women and became evident within one week of the crossover. 2) In the second study, at the end of six months, the patients on SFP plus anticoagulants had a lower incidence of arterio-venous shunt thrombosis (0.18 vs 0.26 thrombi/patient month), but this trend was not statistically significant, 3) Histological examination of the affected veins revealed atheromatous-like changes consisting of intimal thickening due to proliferation of smooth muscle cells some of which contained lipid, increased collagen and extracellular lipid.

These studies further support the efficacy of SFP in the prevention of thrombosis in a high flow system. The stenotic changes closely resemble atherosclerosis and support previous observations that veins exposed to a high pressure, high flow system become susceptible to such changes.
Platelet Aggregation Following Defibrination with Ancrod
Authors: Slade Lawrence C. , Andes Abe W.
Published: June 2019

A transient defect in platelet aggregation was observed following defibrination with Ancrod. Adult mongrel dogs were defibrinated using a slow intravenous infusion of Ancrod. Defibrination was maintained for ninety-six hours. Immediately following defibrination there was a complete ablation of the normal platelet response to thrombin or ADP with a gradual return toward normal aggregation over the ninety-six hour period. Fibrin degradation product titers were highest at the time of maximum inhibition of platelet aggregation. The return to normal aggregation paralleled the fall in the fibrin degradation product titer.
Collagen-Induced Coagulant Activity (CICA) and Factor-V and -XI Activities of Platelets and Platelet Plasma Membranes
Authors: Walsh P. N. , Lipscomb M. S.
Published: June 2019

To examine the hypothesis that collagen-stimulated platelets with associated factor XI can initiate intrinsic coagulation by an alternative pathway not requiring factor XII, platelets were washed using an improved method of albumin density gradient separation and assayed for coagulation factors. Factors II, VII, IX and X eluted readily, VIII and XII less readily; whereas V and XI remained associated. Collagen treatment produced a 2-fold increase in platelet-associated V and XI activities and activation of XI. Freezing and thawing platelets increased V activity 3-fold and XI activity 6-fold and these activities sedimented at 100,000 ×g. Platelet plasma membranes isolated by sucrose gradient centrifugation after glycerol lysis had PF3 activity, (per mg phospholipid) 5-fold greater than human brain phospholipid (Folch) and contained 0.45 units of V and 0.23 units XI per mg protein. Membranes had no detectable II, VII, VIII, IX, X and XII activities, progressively shortened clotting times when preincubated with XII-deficient plasma, and responded to collagen by enhancing XI activity. Platelets and platelet plasma membranes obtained from a patient with normal hemostasis and without apparant plasma XI had normal CICA and greater than normal XI. These observations support the view that XI is tightly bound to platelet membranes and can be activated by collagen in the absence of detectable XII with resultant initiation of intrinsic coagulation, even in the absence of plasma XI.

(Supported by NIH Grant HL 14217 and AHA Grant 73–726.)
Glycoproteins and Cell Adhesion
Authors: Cook G. M. W.
Published: June 2019

Over the last decade the importance of glycoproteins at the cell surface has become increasingly evident. The role of surface heterosaccharides in cell interaction phenomena will be discussed in terms of those macromolecules providing the cell with a recognition surface; the carbohydrate groups of membrane glycoproteins may be expected to provide considerable variation in surface structure, with great economy of means, commensurate with the large number of specific interactions which take place at the cell periphery. Evidence for surface glycoproteins being involved in cell adhesion will be briefly reviewed. That adhesive specificity might be incorporated into the arrangement of sugar residues within the carbohydrate groups of surface heterosaccharides which are recognized by an appropriate glycosyltransferase on the surface of apposing cells, with the formation of mutable adhesions will be detailed by reference to recent experimental evidence, obtained with malignant rat dermal fibroblasts. In this type of work the use of exogenous glycoproteins as model compounds has proved useful, however, the need to isolate endogenous membrane glycoprotein acceptors is evident and the results of current work in this area will be described.
Dengue Haemorrhagic Fever (DHF)
Authors: Wulur Hansa , Himawan T. , Kho L. K.
Published: June 2019

During a period of two years 203 children with DHF were admitted to our department. 102 were boys and 91 girls. Their ages varied between 6 mons. and 14 yrs, (average 6.3 yrs,). The following signs and symptoms were observed namely Viz.: fever, upper respiratory infection, abdominal pain, vomiting, hepatomcgali, disturbance of consciousness, convulsion, shock and haemorrhagic diathesis.

Regarding the haemorrhagic manifestations we could further classify epistaxis in 21.7% of the children, hematemesis in 18.7%, melena in 31.5%, petechiae in 30%, ecchymosis in 12.8%. Furthermore laboratory hematologic examinations revealed the presence of anaemia in 42.8% (Hb less than 10 gm%), hemoconcentration in 35% (Ht value more than 40%), leucopenia 31.3% (WBC value more than 5000/mm3), a prolonged bleeding time in 40.1%, a prolonged clotting time 25.3%, decreased prothrombin index 23.1% (PI less than 75%), prolonged PTT 42.2%, fibrinogenopenia in 48.6%, positive tourniquet test in 56.7%. The overall mortality rate was 11.8%.

It is concluded that haemorrhagic diathesis in dengue haemorrhagic fever is caused by factors affecting the vascular wall, coagulation mechanism as well as thrombocytopenia.
Fatal Pulmonary Embolism and Surgery
Authors: Corrigan T. P. , Kakkar V. V.
Published: June 2019

Several studies have suggested that pulmonary embolism is an important cause of death in patients under going major surgery. These conclusions, however, are based on retrospective case-note analysis and the criteria for diagnosing fatal pulmonary embolism are often not defined. In this paper, we report the findings of a prospective, study involving 2,164 patients over the age of 40 undergoing major surgery. Age, sex, blood group, type of operation performed, the presence of malignancy and of other factors which could possibly predispose to pulmonary embolism were recorded in each case. Operations performed included major abdominal, orthopaedic, gynaecological and urological procedures. The diagnosis of fatal pulmonary embolism was based on the presence at autopsy of emboli in the main pulmonary artery, its first division or the lobar arteries, with no other cause being found for the patient’s death. One hundred patients died during the postoperative period and autopsy examination was performed in 73. Sixteen patients died due to fatal pulmonary embolism as defined above - an incidence of 0.73%. This was the commonest single cause of death recorded, others being pneumonia (13 patients), myocardial infarction (13 patients), peritonitis (9 patients) and miscellaneous (22 patients). The significance of the various factors which may influence the incidence of fatal pulmonary embolism will be discussed.
The Frequency of Coronary Heart Disease and Myocardial Infarction in Patients with Rheumatoid Arthritis
Authors: Czaplicki S. , Gietka J. , Sulek K.
Published: June 2019

The frequency of coronary heart disease and myocardial infarction in 500 persons with rheumatoidearthritis (116 men and 384 women) receiving salicylates during long period time were examined. Coronary heart disease in 2 cases (1 man and 1 woman) and myocardial infarction in 1 man were found.

On the basis of the age and duration observations the authors discovered that the coefficient morbidity was statistically significant lower than in the same population but without rheumatoid arthritis. The coronary risk factors as hypertenia arterialis, hyper-cholestrolemia and diabetes was less frequent than in normal population too. The cigarettes smoking and obesity were found equally frequent.

The authors suggested that long term treatment with acetylsalicylic acid effects inhibition adhesion of platelets and in this way protects before arterial thrombosis and may be artherosclerosis.
Absence of Correlation between Haemorrhagic Lymph and Prolonged Bleeding Time During Experimental Thrombocytopenia
Authors: Aursnes I.
Published: June 2019

The level of circulating blood platelets below which a prolonged bleeding time can be found, is somewhat dependent on the age of the platelets at hand. However, when studying the appearance of red cells in the lymph of animals during experimental thrombocytopenia, no such critical level could be found at all (I. Aursncs, Scand. J. Haemat. 13, 184-195). Thus very low levels of circulating blood platelets with markedly prolonged bleeding time can be seen in animals with no red cell leakage to their lymph.

Those observations have now been somewhat extended by observing the same two-pmeters in rabbits soon after their production of blood platelets has been completely stopped by a more heavy dose of whole body irradiation. Abnormal leakage of red cells to lymph (drained from the ears which had been shielded during the irradiation) the often occurred at levels of 100-400,000 platelets per μl, whereas the bleeding times in the same animals were usually not significantly prolonged until the platelet concentration fell below 50,000 per μl blood.

An explanation for the two described phenomena would be that the vascular supportive effect and the haemostatic effect of blood platelets are dependent on two different mechanisms.
Effect of Splenectomy on Platelet Kinetics in Idiopathic Thrombocytopenic Purpura (ITP)
Authors: Tsukada T.
Published: June 2019

51Chromium-labeled platelet survival and platelet turnover were studied in ten patients with ITP before and after splenectomy. Prednisolone was administered during the platelet survival study in all cases. Platelet mean survival time (MST) was moderately reduced before splenectomy. Prolongation of MST accompanied an increase of peripheral platelet count in 7 cases after splenectomy. In two cases MST and platelet count did not change significantly after splenectomy although platelet recovery value increased remarkably. Platelet turnover (effective platelet production) was greatly above normal before splenectomy in all cases and reduced to normal range after splenectomy in only two cases. Highly, significant linear correlation was noted between MST and peripheral platelet count. But no linear correlation was found between platelet turnover and platelet count (r = -0.48).

It was concluded that an increase of peripheral platelet count after splenectomy was mainly due to the prolongation of MST irrespective of the change of platelet production.
Factor XIII In Henoch-Schönlein’s Purpura
Authors: Henriksson P. , Nilsson J. M. , Hedner U.
Published: June 2019

The increased bleeding tendency in Henoch-Schönlein’s purpura has been attributed to increased vascular permeability. Gastrointestinal bleeding in these patients may be fatal. Coagulation and fibrinolytic studies have been performed in 7 patients with Henoch-Schönlein’s purpura. A 9-year old boy had a life-threatening gastrointestinal bleeding which had required 20 bottles of blood per day. It was found that all 7 patients had low levels of factor XIII determined with the dansylcadaverine method of Lorand et al. (1969). The values ranged between 4 and 8 FSF U/ml (mean 6 FSE U/ml ; normal range 11-31 FSF U/ml). Other coagulation and fibrinolytic parameters were normal.

Administration of factor XIII concentrate promptly stopped the bleeding in the above mentioned 9-year old boy. On recovery the factor XIII values normalised.
Action of Plasmin on Plasma Membranes of Human Platelets
Authors: Matsuda S. , Muraki H. , Ando Y. , Hasegawa M.
Published: June 2019

The action of plasmin on plasma membrane polypeptides of human platelets was studied with the aid of polyacrylamide gel disc electrophoresis in sodium dodecyl sulfate.

When isolated membranes were treated with plasmin, a minor polypeptide band of mol. wt. 120,000 disappeared completely and major polypeptide bands of mol. wt. 40,000 and 100,000 were reduced in concentration.

Plasmin digestion of intact platelets coupled with subsequent membrane isolation and gel electrophoresis resulted in only a slight decrease in staining intensity in a glycopeptide band with a mol. wt. 100,000.

Platelet membranes contain more than three plasmin substrates, most of which, however, are resistant to this enzyme in intact platelets because of their orientation in the membranes and some other mechanisms.
Quantitative Determination of Prothrombin and its Fragments in Plasma and Serum
Authors: Hassouna H. , Reuterby J. , Walz D. , Hewett-Emmett D. , Seegers W. H.
Published: June 2019

A comparison of immunochemical and biological methods for quantitative determination of human and bovine prothrombin and its activation fragments in fresh and stored human and bovine plasma and serum is presented. High titered monovalent antisera to prothrombin and specific antisera to PR and 0 fragments produced in rabbits were characterized by radio immunoelectrophoresis and the Feinberg technique using I125 labelled antigens. Prothrombin and PR antisera neutralized prothrombin activity of plasma when tested by the prothrombin clotting assays, while bovine 0 fragment was found bound to Acglobulin in plasma adsorbed with barium carbonate. Antibodies insolubilized by coupling to Bio Gel A-15M were used to deplete fresh plasma of corresponding protein. Depleted plasma was reconstituted by adding varying dilutions of fresh plasma or I125 labelled antigens, and amounts of antigen needed to restore its property to form a standard clot was estimated by the Laurell “rocket” technique, and by hemagglutination inhibition. The purpose of the study is to select a suitable quantitative immunoassay to measure antigenically active prothrombin and its fragments in plasma and serum of normal men, women and children grouped according to estimated blood pressure, age and weight.

(Supported by Skillman Foundation of Detroit.)
Regulation of Glycolysis During Collagen Induced Aggregation of Human Platelets
Authors: Akkerman J. W. N. , Gorter G. , Sixma J. J. , Staal G. E. J.
Published: June 2019

In previous studies we clarified the regulatory properties of purified human platelet 6-phosphofructokinase (EC. 2.7.1.11). We now present data that this enzyme exhibits regulatory properties not only in a purified system but also in the living platelet. Human platelets were isolated by gel Chromatography on Sepharose-2B equilibrated in a Ca++ containing buffer. Subsequently the suspension was concentrated by repeated dialysis against polyethyleneglycol 20,000. The final suspension closely resembled platelet rich plasma with respect to aggregability, platelot factor 3 availability and adenylate energy-charge. At 37°C a continously stirred suspension showed stable levels of glu-6-P and fru-3-P. Fru-1,6-P2 concentration dropped 80% in a 20 min period and thereafter remained constant. Dihydroxyacetone-P showed a similar pattern. Pyruvate and lactate were produced at a constant rate. These data reflect a low phosphofructokinase activity.

This pattern was disturbed by the addition of collagen. This led to an extra production of pyruvate and lactate illustrating an increased glycolytic flux. After the addition of collagen Fru-1,6-P and dihydroxyacetone-P immediately increased and only after 30 min these levels reached pre-aggregation values again. Since the levels of other glycolytic intermediates were only slightly changed, the extra flux may be related to the increased levels of intermediates immediately formed after the phosphofructokinase reaction, e.g. to increased phosphofructokinase activity.

Furthermore since aggregation is maximal 2 min after collagen addition the prolonged increase in phosphofructokinase activity suggests that glycolysis mainly has the task to replenish energy utilized by the aggregation and release process.
Atherothrombotic Cardiovascular Mortality Among Greek Farmers
Authors: Aravanis C. , Corcondilas A.
Published: June 2019

Cardiovascular atherothrombotic deaths (CVAD) have been determined for the past 14 years among farmers on the island of Crete, Greece, as part of an International Cooperative Study. Subjects no. 686 were males, age 40–59 initially in 1960, and are followed since.

Variables of interest taken into consideration were body fatness, serum cholesterol, blood pressure, electrocardiogram at rest and after exercise, physical activity, occupation, lung function, smoking and other habits. Incidence and precalence of CVAD i.e., coronary (CHD), cerebral (CVA), and peripheral (PAD) arterial diseases have been determined bi-annually in addition to 5-year complete follow-ups.

Mortality per year per 10,000 was 5.2 for CHD, 5.2 for CVA and zero for PAD. Total all-causes mortality was 64 per year per 10,000.

From these data CVAD are extremely rare andin comparison with other western countries among these Greek farmers. All-causes deaths are also low, as a result of low cardiovascular mortality. The reasons and the interrelationships among measured parameters are discussed.
Electroencephalography and Epilepsy Course at UH Cleveland Medical Center, Cleveland, Ohio, United States
Authors: Park Jun T. , Devereaux Michael , Abboud Hesham , Ashraf Fareeha , Cohen Mark , Couce Marta , DeBrosse Suzanne , Fastenau Philip , Vaca Guadalupe Fernandez-Baca , Garcia-Losarcos Naiara , Kahriman Mustafa , Lacuey Nuria , Marsey Marge , Miller Jonathan , Rosen Carol , Shahid Asim , Tangen Rachel , Wien Michael , Lüders Hans
Published: June 2019

Prof. Hans Lüders organized the first International Electroencephalography (EEG)/Epilepsy course in Cleveland (Ohio, United States) in 1979. His vision was to impart a framework of basic knowledge in EEG and epilepsy. The course participants are assumed to have no prior knowledge of EEG or epilepsy. As such, the course is structured and paced to meet the expectations set forth by the organizing committee at the completion of the course. The curriculum has evolved over the years to reflect advancement of the field. There is an added emphasis on semiology (seizure semiology) and epileptic disorders. Also, the course content has expanded to include broader topics such as the intersection between epilepsy and sleep medicine for both adults and children. The course lasts 8 weeks and is offered twice a year, free of charge, in winter and summer at the University Hospital in Cleveland, Ohio, United States. The average class size ranges from 25 to 30, composed of individuals from around the world. The class hours are generally from 8 a.m. to 3:30 p.m. Daily attendance is expected as new concepts quickly build on previous ones. Midterm and final examinations are used for evaluations. Both written and verbal feedbacks on homework assignments are given daily. At the end of the course, a certificate of completion is awarded. The purpose of this article is to discuss the structural details of this intensive educational course that has been offered for 40 years.
Ultra-narrowband absorption enhancement in monolayer transition-metal dichalcogenides with simple guided-mode resonance filters
Authors: Qing Ye Ming , Ma Hui Feng , Yu Shang , Cui Tie Jun
Published: June 2019

A simple guided-mode resonance filter composed of a single layer of molybdenum disulfide (MoS2), a dielectric grating, and a dielectric substrate is designed to enhance light absorption in the visible range. The absorption characteristics of the system are investigated and analyzed by using the rigorous coupled-wave analysis method and the slab waveguide theory. The results reveal that the high absorption over 65% can be obtained for TE polarization and over 53% for TM polarization. Intriguingly, the structure exhibits an ultranarrow absorption bandwidth under TM polarization, the full width at half maximum is only 0.51 nm, and the quality factor can be more than 1200. In addition, multichannel absorption can be realized by increasing the thickness of the grating layer. The resonant wavelength can be dynamically selected by merely tuning the incident angle. The proposed device with its simple design can be applied to enhance the absorption of other two-dimensional materials.
A new additive decomposition of velocity gradient
Authors: Sun Bohua
Published: June 2019

To avoid the infinitesimal rotation nature of the Cauchy-Stokes decomposition of velocity gradient, the letter proposes an new additive decomposition in which one part is a SO(3) rotation tensor Q = exp W.
A double exponential potential for van der Waals interaction
Authors: Wu Xiongwu , Brooks Bernard R.
Published: June 2019

Van der Waals (vdw) interaction is an important force between atoms and molecules. Many potential functions have been proposed to model vdw interaction such as the Lennard-Jones (L-J) potential. To overcome certain drawbacks of existing function forms, this work proposes a double exponential (DE) potential that contains a repulsive exponential term and an attractive exponential term. This potential decays faster than the L-J potential and has a soft core. The DE potential is very flexible and its two exponential parameters can be adjusted continuously to mimic many potential functions. Combined with the isotropic periodic sum (IPS) method, the DE potential can efficiently and accurately describe non-bonded interactions and is convenient for alchemical free energy calculation.
On the performance of modern digital grammar checkers for native and second language learners
Authors: Bril Marco
Published: June 2019

In this study we conducted an experiment aiming to compare the performance of language learners and digital grammar checkers at supplying gender marking in French. A set of test items exhibiting typical gender marking configurations was submitted to three grammar checkers for French (Antidote, Scribens and BonPatron). The outcomes were compared to those of native speakers and second language learners of French at a B1 level.

The results revealed that only Antidote and Scribens outperformed both native speakers and second language learners of French in adjective-noun and fronted noun-past participle agreement constructions. An opposite pattern, however, appeared for clitic-past participle constructions for which native speakers outperformed Antidote and Scribens.

We thus conclude that from the three grammar checkers under investigation, Antidote and Scribens might be effective to improve the native speakers’ and second language learners’ awareness of gender marking errors, but only in adjective-noun and fronted noun-past participle agreement constructions.
The adjuvant GLA-SE promotes human Tfh cell expansion and emergence of public TCRβ clonotypes
Authors: Hill Danika L. , Pierson Wim , Bolland Daniel J. , Mkindi Catherine , Carr Edward J. , Wang Jiong , Houard Sophie , Wingett Steven W. , Audran Regine , Wallin Elizabeth F. , Jongo Said A. , Kamaka Kassim , Zand Martin , Spertini Francois , Daubenberger Claudia , Corcoran Anne E. , Linterman Michelle A.
Published: June 2019

The generation of protective humoral immunity after vaccination relies on the productive interaction between antigen-specific B cells and T follicular helper (Tfh) cells. Despite the central role of Tfh cells in vaccine responses, there is currently no validated way to enhance their differentiation in humans. From paired human lymph node and blood samples, we identify a population of circulating Tfh cells that are transcriptionally and clonally similar to germinal center Tfh cells. In a clinical trial of vaccine formulations, circulating Tfh cells were expanded in Tanzanian volunteers when an experimental malaria vaccine was adjuvanted in GLA-SE but not when formulated in Alum. The GLA-SE–formulated peptide was associated with an increase in the extrafollicular antibody response, long-lived antibody production, and the emergence of public TCRβ clonotypes in circulating Tfh cells. We demonstrate that altering vaccine adjuvants is a rational approach for enhancing Tfh cells in humans, thereby supporting the long-lived humoral immunity that is required for effective vaccines.
Active species densities in R/x%N2 and R/x%(N2-5%H2) (R = Ar or He) microwave early afterglows
Authors: Ricard A. , Sarrette J.P.
Published: June 2019

Afterglows of R/x%N2 and R/x%(N2-5%H2) (R = Ar or He) flowing microwave discharges are characterized by optical emission spectroscopy. Absolute densities of N-atoms, N2(A) and N2(X,v>13) metastable molecules and N2
+ ions and evaluated densities of NH and H are determined after calibration of the N-atom density by NO titration. New results on NH radical and H-atom relative densities are obtained by considering that the excitation of the NH(A) radiative state in the afterglow is produced by N2(X,v>13) + NH collisions. The interest of these results concerns the enhancement of surface nitriding by combined effects of N and H atoms inclusion in afterglow conditions.
Study on reaction rates for 2T SF6 plasma: application to chemical kinetics of a decaying arc in high voltage circuit breakers
Authors: Baumann X , Teulet Ph , Cressault Y , Bultel A
Published: June 2019

This work is devoted to the study and comparison of theories to calculate densities of chemical species in a SF6 plasma in thermal non equilibrium conditions. The limits of the 2T law of mass action are shown. Then, the reaction rates are studied for several types of processes and they are implemented in a chemical kinetic model to acess the composition of the plasma. Finally, a comparison with the densities obtained with the law of mass action is performed and the results are discussed.
Analysis of Gas Metal Arc Welding (GMAW) regime transition in Ar-CO2/O2 shielding gases
Authors: Castillon Quentin , Wartel Maxime , Pellerin Nadia , Pellerin Stéphane , Faubert François , Planckaert Jean-Pierre , Briand Francis
Published: June 2019

An experimental study on MIG-MAG welding in reverse polarity (anode wire) has been implemented to analyse the influence of the active gas type and composition on the welding process. The analysis of the arc column using optical emission spectroscopy and high speed imaging completed by µ-structural study of the electrode wire by EDS/XRD and EPMA methods have provided helpful explanations on the globular/spray mode transition depending of the active gas in the shielding gas. These results highlight the existence of an oxide layer (“gangue”) and the modification of the typology of this one in globular mode according to the active gas (Ar/CO2 or Ar/O2) probably responsible of the globular/spray mode transfer by modification of the electrical/thermal conductivities of the oxide layer. Spectroscopic analysis reveals modification by an arc constriction in Ar/O2 mixtures and linked to a more prominent drop of the electronic temperature along the arc column axis. With this active gas, analysis of the Fe I / Ar I emissivity ratio show a higher metal vapours content responsible for the temperature drop by their strong radiative emission along the arc column.
Anisotropic plasma etching of Silicon in gas chopping process by alternating steps of oxidation and etching
Authors: Miakonkikh A.V. , Averkin S.N. , Rudenko K.V.
Published: June 2019

In the present work a two-stage process for deep anisotropic etching of Silicon based on alternating steps of etching in SF6 plasma and passivation of Silicon surface by oxidation in O2 plasma is proposed. This developed Ox-Etch process has advantages of being free from deposited polymers on sidewalls and does not use cryogenic equipment. Etched structures show anisotropic profile with vertical scalloped walls similar to Bosch and STiGer processes. Selectivity of Silicon etch process with respect to SiO2 mask is up to 120:1. The investigations of etching results depending on process parameters are presented. Main control parameters for Ox-Etch process defining the etch rate and degree of anisotropy are the durations of etch and oxidation steps.