bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy Of Different Heparin Regimens In Dialysis As Assessed By Radioimmunoassay For Fibrinogen/Fibrin Split Products
Authors: Kudryk B , Wilhelmsson S , Netré C , Robinson D , Blömback M
Published: July 2018

Three different heparin regimens were employed to control clotting in uremic patients undergoing hemodialysis. The regimens differed with regard to dose prior to and/or during dialysis. The efficacy of heparin was checked with several parameters including blood levels of fibrinogen/fibrin split products. Blood was collected from each patient prior to and at three time points during dialysis. Samples were taken from both the blood inlet and outlet sides of the dialyser. Fibrinopeptide A (FPA) was determined by radioimmunoassay (RIA). Hi-2DSK (an Aα-chain derived split product) levels were measured by RIA using selected chromatography fractions of patient plasma and a new RIA method was used to measure plasma levels of split products which contain the Bβ 15-42 sequence.

FPA levels were lower during heparin infusion but rose after it was terminated. Blood from the outlet efferent side of the dialyser usually showed higher FPA levels. Hi-2DSK and Bβ 15-42 concentrations were always high before and during dialysis, sometimes 10-20 times or more that found in normal subjects. However, they never showed the variation observed for FPA. Also, in most cases, the levels were similar regardless from which side of the dialyser the samples were obtained.

All three regimens were equally as effective in preventing FPA generation in the dialyser. FPA estimation may be used to check adequacy of heparin dosage. Assays for the other two split products indicate no significant elevation of fibrino(geno)lysis during four hours of dialysis.
Interaction Between Human Blood Platelets And Polymorphonuclear Leukocytes In The Metabolism Of Arachidonic Acid
Authors: Killackey J J , Killackey B A , Philp R B
Published: July 2018

In a study of human polymorphonuclear leukocyte (PMN) prostaglandin (PG) biosynthesis from exogenous l4C-arach- idonic acid (14C-AA), we found that combinations of platelets and PMN produced different TLC profiles of AA metabolites than either pure platelets or relatively pure PMN alone. Cells were separated from citrated whole blood by ficoll-sodium diatrizoate density gradient centrifugation. Washed platelets were prepared from citrated platelet-rich plasma. Cells were incubated with 30 uM 14C-AA for 15 m at 37°C in phosphate buffered saline with or without 2-10 mg/ml serum-treated zymosan (STZ). AA metabolites were extracted and measured by radio-thin layer chromatography compared to known standards. Under these conditions, washed platelets (1.5xl07) produced peaks of radio-activity corresponding to, in decreasing order, PGE2, PGD2 and thromboxane B2 (TXB2). 10 mg/ml STZ reduced the PGE2 peak by 60%, inhibited the PGD2 peak but did not alter the TXB2 peak. Indomethacin (20 uM) inhibited all peaks under all conditions. Relatively pure PMN (l.5xl07) containing platelets in a ratio of 1:10 PMN metabolized small amounts of AA but this increased dramatically upon the addition of STZ. Although peaks of activity corresponded to TXB2 and PGD2 they were not inhibited by ASA (500 uM) or indomethacin (50 uM) but were inhibited by 5 ug/ml nordihydroguaiaretic acid. This suggests that they are lipoxygenase products. PMN samples containing platelets in a ratio of 1:3 PMN produced aximum activity corresponding to TXB2 and this, in contrast .0 platelets or PMN alone was augmented upon addition of 10 mg/ml STZ. This increase was inhibit able with cyclooxygenase inhibitors. These results suggest that platelets and PMN interact in the presence of STZ and AA and this interaction may play a role in inflammation.
Platelet Aggregation In Relation To Cigarette Smoke, Carbon Monoxide (CO) And Nicotine
Authors: Mansouri A
Published: July 2018

There is no doubt that the incidence of atherosclerosis is significantly increased in heavy smokers. Although this increase is most likely due to multiple factors, one factor which has been mostly incriminated is abnormal platelet function. In fact, it has been shown that the smokers have augmented platelet aggregability which might signify higher platelet turnover leading to athero- genesis. This work was undertaken to test directly the effect of smoke and its major constituents on platelet aggregation. Blood was obtained from healthy non-smokers without previous medication. Platelet rich plasma was prepared with standard methods. The aggregation was carried out with epinephrine, thrombin and arachidonic acid (AA) with and without smoke, CO and nicotine. It is shown that nicotine in concentrations up to 2 μg/ml (50 times higher than nicotine concentration in heavy smokers) has no effect on platelet aggregation regardless of the aggregating agent used. Carbon monoxide at high concentration inhibits tne secondary wave of aggregation when epinephrine is used (slope of secondary wave of aggregation 0.92 ± 0.25 for normal versus 0.53 ± 0.12 in the presence of CO) ano little or no aggregation takes place with thrombin ano AA. The smoke does not affect platelet aggregabi1ity when it is subjected to vacuum prior to use. These results indicate a) that the major effect of smoke on platelets is mediated by CO, b) carbon monoxide inhibits the secondary wave of aggregation (aspirin-like effect) contrary to what has been reported in vivo.

These results suggest that smoke or its major components do not have any direct stimulatory effect on platelet aggregation.
Specific Desensitization Of Washed Rabbit Platelets By Paf-Acether And Derivatives
Authors: Lalau Keraly C , Tencé M , Heymans F , Benveniste J
Published: July 2018

PAF-acether-aggregated rabbit platelets did not respond to a second challenge with the same agonist after their spontaneous disaggregation, but still aggregated in the presence of arachidonic acid (AA). When using 1 nM of PAF-acether in the first stimulation, aggregation in response to a second challenge with the same dose was nil. However, when 0.34 nM was used in the first step, aggregation in response to 0.64 nM PAF-acether was 59 96, as compared to control platelets. By contrast, aggregation of platelets pretreated with 1 nM PAF-acether was 72 % in the presence of 2.8 uM AA. Adding fibrinogen (0.34 mg/ml) before the second stimulation did not modify the desensitization pehnom- enon. Supernatants from platelets desensitized with 1 nM PAF- acether exhibited neither aggregating nor inhibitory activity. PAF-acether-induced desensitization could always be overcome, since aspirin-pretreated platelets first stimulated with 10 nM PAF-acether still aggregated with 100 nM of the same agonist, i.e. when using 100 times the amount which induced maximal aggregation. All our experiments were performed in the presence of ADP scavengers and, except for AA-induced aggregation, aspirin. We tested PAF-acether from 4 different cell origins and the semi-synthetic and synthetic compounds. Platelets were cross- desensitized towards PAF-acether from any source. Totally synthetic PAF-acether bearing aC,, alkyl chain at position 1 of the glycerol moiety desensitized platelets as well as the C.g synthetic analog. Lyso-PAF-acether (i.e. a compound lackifig tne acetyl group at the position 2 of the glycerol) (0.5-10.0 nM) and PAF-acether enantiomer (0.5-5.0 nM) neither aggregated nor desensitized platelets to PAF-acether. These results indicate that 1) PAF-acether from any source exhibit at least an identical active molecular site ; 2) the presence and the stereospecific position of the 2-acetyl group are critical for the interaction of PAF-acether with platelets, a result which could indicate the existence of a platelet acceptor (receptor) for PAF-acether. However, these postulated platelet membrane acceptors were never saturated even using very high amounts of the agonist.
The Appearance Of PF1 And PF3 In Activated Human Platelets
Authors: Sandberg H , Bodet A P , Dombrosei F A , Andersson L O , Lentz B R
Published: July 2018

Collagen and thrombin induced platelet activation were examined, in vitro, with regard to the appearance of surface-associated Factor V-like activity (PF1) and catalytic phospholipid-like surface activity (PF3). Two test systems were used: a clotting assay (a modified KAPTT) and a chromogenic substrate assay (maximum hydrolysis of S-2238). Following stimulation of normal platelets, both PF1 and PF3 appeared simultaneously in the supernatant and platelet pellet. When normal platelets were collected and carefully washed in a buffer containing adenosine, PGE1, and theophylline, the appearance of both PF1 and PF3 was blocked, as was the release of ATP from dense granules, the release of β-TG and PF4 from α-granules, and the occurrence of aggregation. When platelets were collected in this same inhibitor-containing buffer, and then gel filtered/centrifuge-washed in an inhibitor-free buffer, the appearance of PF1 and PF3 was still blocked. This occurred even though release of ATP, β-TG and PF4 as well as aggregation followed a pattern equivalent to platelets never exposed to these inhibitors. When the release supernatant from normal platelets isolated in the absence of inhibitors was gel filtered on Sepharose CL-4B in the presence of EDTA, the carbohydrate-free, lipid- protein particles (70-170nm diam.) that provide PF3 appeared in the void volume. When the release supernatant from normal platelets was gel filtered in the presence of Ca2+, both, PF1 and PF3 eluted in the void volume. With platelets isolated from severe F.V-deficient donors, only PF3 was found in the void volume, in the presence or absence of Ca2+. It seems that the appearance of PF1 and PF3 as coagulant activities is completely separate from both the release of dense granule and α-granule contents as well as platelet aggregation and that the appearance of PF1 requires the presence of Ca2+.
Characterization Of Rabbit Antithrombin III
Authors: Estry D , Mattson J C , Bell T G , Tishkoff G H
Published: July 2018

The rabbit is a well established model for studying the disseminated intravascular coagulation (DIC) associated with endotoxic syndromes. In order to establish the role of antithrombin III (AT III) in the modulation of DIC in the rabbit, characterization of rabbit AT III was undertaken. Rabbit antithrombin III, isolated according to modifications of the method of Thaler and Schmer, has a molecular weight comparable to that of human AT III (62,000 daltons) as measured by mobility on SDS-PAGE gels. Mixtures of rabbit and human AT III co-migrate as a single band on 7.5% SDS-PAGE gels. Rabbit AT III possesses both progressive and heparin activated (immediate) antithrombin activity in assays using human thrombin. Antisera raised against rabbit AT III demonstrates no cross reactivity with human AT III suggesting that despite physiologic and molecular weight similarities, antigenic differences are present. Incubation of rabbit antithrombin III with specific antisera, either prior to or after addition of heparin, did not alter the ability of antithrombin III to inhibit thrombin in either the immediate or progressive assays indicating that the antigenic determinants are not found in either the heparin binding or active thrombin binding sites. Crossed immunoelectrophoresis (IEP) demonstrates that antisera to rabbit AT III reacts with both free rabbit antithrombin III and AT III-thrombin complexes and can therefore be used in immunologic assays to quantitate total rabbit AT III (bound and free) and in crossed IEP to demonstrate the mobility of both free and complexed AT III.
Congenital Abnormal Antithrombin III
Authors: Sakuragawa N , Takahashi T , Horikoshi I
Published: July 2018

We found a family which had congenitally abnormal antithrombin III (AT-III ) showing remarkable difference between biological and immunological activity. We studied genetic trait and effects of heparin and thrombin on AT-III.

Case: A 23 years old female developed thrombophrebitis on her left leg in July, 1979. After a while she seemed to have developed thrombi on bilateral iliac vein. She had also abdominal tumor, and a cystic kidney was found to be by an exploratory laparatomy. Five days after the operation, she was hemiparalyzed on her left. Cranial angiography disclosed obstruction of right middle cerebral artery by thrombi. Laboratory findings were as follows: Fibrinogen 145 mg/dl, FDP 40 ug/ml, platelets 8.6xl04/cmm, a-PTT 30.6 sec and PT 100%. The biological activity of AT-III was 26%, which dissociated from immunological activity of 54 mg/dl. Two dimension immunoelectrophoretical analysis showed two or three peaks at the albumin area after the addition of heparin to normal AT-III. However her AT-III did not move from α2-macroglobulin area. Her parents were cousins each other, and her parents and her sister also had abnormal AT-III. This indicates congenitally abnormal AT-III is transmitted autosomally dominantly. The administration of concentrated AT-III preparation raised its concentrate to 70%, and coagulation disorders disappeared. Immunoelectrophoresis revealed that administered AT-III disappeared in five or seven days after infusion. Oral anticoagulant therapy could prevent thrombi formation.

Conclusion: We found a patient who had abnormal AT-III which brought on intravascular coagulation. Biologically active AT-III was much less than immunologically active one. Immunoelectrophoresis disclosed this AT-III did not bind with heparin. We treated the patient with oral anticoagulant therapy. Abnormal AT-III is transmitted autosomally dominantly.
Changes In Triphosphatidylinositol Metabolism During PGE1- Induced Shape Change Of Washed Rabbit Platelets
Authors: Vickers J D , Kinlough-Rathbone R L , Mustard J F
Published: July 2018

Since the inositol phospholipids are present in small amounts in platelets and turn over rapidly during platelet shape change, aggregation and release, they are thought to have a functional rather than structural role in platelets. We have previously reported that within 10 sec of stimulation of prelabeled, washed rabbit platelets with ADP, the amount of triphosphatidylinositol (TPI) is significantly reduced while the specific radioactivity of its [32p]phosphate is increased. One explanation of this result is that ADP- stimulation may divert ATP required for phosphorylation of diphosphatidylinositol (DPI) to TPI, leading to a decrease in the amount of TPI. PGE1 (10 μM) causes conversion of ATP to cAMP and induces a transient platelet shape change. The shape change may be due to the reduction in ATP with a concomitant fall in TPI. We have therefore studied whether PGE1-stimulation of washed rabbit platelets prelabeled with [32P] causes a change in TPI. Within 10 sec the amount of TPI in PGE1-treated platelets was reduced from 2.22 nmoles/ 109 platelets to 1.98 nmoles/109 platelets (p<0.05) although neither the [32P] labeling (51.1 × 103 dpm/109 platelets) nor specific radioactivity (24.1 × 103 dpm/nmole) were significantly changed. These results are compatible with the theory that diversion of ATP by PGE1-stimulation of cAMP formation from ATP, may reduce the amount of TPI. A similar effect was observed previously with ADP-stimulation. PGE1 caused no change in the [32p] labeling of phosphatidic acid (PA) (ADP caused a 290% increase) and caused only a small increase in its specific radioactivity (16% compared to 270% with ADP). If the rates of turnover of TPI and PA which are reflected in their specific radioactivities are Ca2+- dependent, Ca2+ sequestration due to increased cAMP levels induced by PGE1 would, after the initial effects, terminate these changes. The results further support the suggestion that reduction in the amount of TPI may be involved in platelet shape change and initiation of aggregation.
Disturbed Plasmatic Modulation Of Arachidonic Acid (AA) Metabolism In Platelets From Rats With Nephrotic Syndrome: An Early Parameter Of Thrombotic Risk?
Authors: Delaini F , Reyers L , Vitti G de Beilis , Poggi A , Donati M B
Published: July 2018

The nephrotic syndrome in humans is associated with an increased risk for arterial and venous thrombosis, the pathogenesis of which appears to be very complex. We have developed an experimental model of nephrotic syndrome in rats which follows a single i.v. injection of adriamycin (AIM, 5-10 mg/kg b.w.). Starting from 2 weeks after ADM-injection, rats showed a remarkably increased susceptibility to thrombotic stimuli; indeed, the occlusion time of a polyethylene cannula inserted in the abdominal aorta was 22±15 hours in treated animals versus 62±5 in control animals (n=16, p< 0.001). Concomitantly the rats showed: increased plasma fibrinogen and factor VIII: C activity, shortened APTT, low antithrombin and markedly depressed fibrinolytic activity. Moreover, platelet-rich plasma (PRP) of treated rats produced significantly higher amounts of both malondialdehyde (MDA) (spectrophotometric assay) and thromboxane B2 (RIA) in response to AA. When MDA generation was studied with a kinetic approach, the PRP of nephrotic animals had significantly lower apparent Km for AA in respect to the controls (0.15 ± 0.07 mM AA versus 0.90 ± 0.25 mM AA, p<0.01). Washed platelets from both groups, in contrast, showed similar Km values for AA (0.10 mM ± 0.04 versus 0.12 ± 0.03).

MDA generation by washed normal platelets resuspended in plasma was normal if plasma had been collected 1 or 3 days after ADM administration but was already significantly higher with plasma collected 5, 7 or 14 days after treatment. The concomitant mild hypoalbuminemia does not completely account for this plasma abnormality. Thus, in the model, an abnormal plasmatic modulation of platelet AA metabolism could be detected much earlier than the coagulation/fibrinolysis changes and the hypersensitivity to thrombotic stimuli.
A Multidisciplinary Approach To Hemophilia At A New Regional Center; How Effective Is It?
Authors: Andes W A , Smith W B , Wulff K , Ohene-Frempong K , Sonis A , Edmunds O
Published: July 2018

This study reports data on 74 patients initially evaluated for bleeding disorders at a one year-old hemophilia center. These patients represent a majority of 100 patients currently using any replacement therapy in the state’s hemophilia program. Thirty-five percent of the patients were self-referred, 45% professional-referred, and 20% came to the center through advice from the state NHF Chapter. Diagnoses established were factor VIII deficiency (65%), Christmas disease (19%), von Willebrand’s disease (10%), factor XI deficiency (1 patient), and severe carrier status for factor VIII (6%). Factor VIII inhibitors were found in 7 patients. Several patients did not know their deficient factor, most did not know their inhibitor status, and only 2 patients knew that they had inhibitors. Approximately 50% of the patients were receiving adequate replacement therapy prior to being seen. Care in 5 patients has not improved after their center visit (1 died, 1 is retarded, 2 resist advice or therapy in a rural area, and 1 generally rejects therapy for bleeding for her severe von Willebrand’s disease). Home therapy was available to 32% of patients when initially seen, and 21% more went on home therapy later. A startling number of patients (20% of all) required replacement therapy for untreated bleeds which began within 12 hours prior to a center visit, although 86% of the patients travelled by auto to the visit. Data on 68 patients suggests that they spend an average of $6,500 per year on factor concentrate. Since the immediate family averaged 5.3 persons and the mean income was only $12,500, the burden of the disease was great. Although at least 30% of patients are receiving improved care since their initial center visit, several patients do not yet avail themselves of resources available in this region. Only long-term, even relentless efforts will correct some less than optimal aspects of therapy and such efforts are being made.
An Acquired Von Willebrand’s Disease With IgG Monoclonal Gammopathy, Normal Bleeding Time And Positive VIIIR:AG In The Vascular Endothelium
Authors: Kimura A , Aihara M , Tanabe K , Momma T , Chiba Y , Yoshida Y
Published: July 2018

A 71-year old female noticed nose bleeds a year ago and diagnosed to have an acquired von Willebrand’s disease with IgG, K monoclonal gammopathy. VIII:C was of 0.10 U/ml, VIIIR: AG and VIIIR: WF of both below 0.05 U/ml. Bleeding time was within normal limit by both Duke’s(5 min.) and Ivy’s (7 min.) methods. Platelet retention rate was 10% by Bowie’s method. Ristocetion induced platelet aggregation was nil at 1.2mg/ml of concentration. Serum Immunoelectrophoresis showed K type IgG M-bow, but the IgG value was within normal limit (1,407 mg/dl). Bone marrow findings were normal. Over response of VIII: C following the infusion of cryoprecipitate was not seen. Her profuse epistaxis was stopped when the cryoprecipitate was administered but not the Factor VIII concentrate. Patient plasma showed an inhibitory effect to VIII: C (1.12 Bethesda unit), VIIIR: AG and VIIIR: WF. By immunefluorescent staining VIIIR: AG was proven to be present in normal quantity in the vascular endothelium and platelet surface.
Chromogenic Substrates And Activated Forms Of FXII: Comparison Between The α- And β-Forms And Selectivity With Regard To Plasma Kallikrein And FXIa
Authors: Aurell L , Gustavsson S , Friberger P
Published: July 2018

Activated FXII of both the α-(MW 80000) and the β-(MW 28000) form was tested with a large number of chromogenic tri- and tetrapeptides. The activities of the two enzymes correlated well (r=0.84, n=30). The α-form appeared to have a somewhat higher specificity.

The plasma kallikrein substrate S-2302 and the FXa substrate S-2222 have earlier been shown to be the commercially available substrates most sensitive to the β-form of activated FXII . The specific activities of both the α-and β-forms are the same with S-2302 in the system tris buffer pH 8.0 and I 0.05 at 37°C. At the enzyme concentration of 4 nmol/1, the change in absorbance per min was 0.02 which is in the suitable measuring range. This concentration is approximately equivalent to fully activated plasma diluted 1:100.

From these findings, it could be confirmed that when plasma prekallikrein is assayed via contact activation with S-2302, there is a definite but small contribution to the hydrolysis of the substrate from activated FXII.

A more selective substrate for activated FXII with regard to plasma kallikrein would be preferable in a plasma assay of FXII. S-2222 has these characteristics. At the substrate concentration of 0.33 mmol/1, the β-form of activated FXII splits S-2222 essentially as efficiently as S-2302 while plasma kallikrein is only 5% as efficient with S-2222 as with S-2302.

Both types of substrates are insensitive to FXIa at concentrations obtainable in plasma samples suitably diluted for the assaying of FXII and plasma prekallikrein.
In Vitro Generation Of E-Neoantigen Measured By Radioimmunoassay
Authors: Chen J P , Williams T K
Published: July 2018

We generated in vitro fibrinogen degradation products (FDP) and determined which fibrinogen (Fg) fragments could be detected by E-neoantigen radioimmunoassay (RIA). Rabbits were immunized with fragment E derived from the plasmin cleavage of Fg, and the anti-Fg-E sera were absorbed with native Fg. The absorbed antisera contained antibodies which reacted with Fg-E (but not with Fg) and its related FDP via neoantigenic expression of Fg-E (Fg-Eneo). Fg was digested by urokinase-activated plasminogen at 37°C for varying periods from 5 min to 16 hr. A double antibody RIA using anti-Fg-Eneo and an 125I-Fg-E tracer showed progressive exposure of Eneo after digesting Fg for 2 hr (fragment X). The inhibition curve of the 4 hr-digest (fragment Y) exhibited a parrellism to that of Fg-E standard; however, the 50% inhibition point of the 4 hr-digest was noticeably displaced. According to Scatcherd plots of the bound/free ratio of Fg-absorbed and unabsorbed anti- Fg-E, both anti-Fg-E and anti-Fg-Eneo contained antibodies that were heterogeneous. These findings suggest that radioimmunologically Y (but not X) fragments were detected as identical molecular species of Fg-E. The Eneo will also be generated in plasma by urokinase-activated plasminogen. The reaction between anti-Fg-Eneo and X, Y or E fragment will be inhibited by timed plasmin digests.
Application Of Enzymatic Methods On Chromogen Substrates In Animal’S Compared Coagulation
Authors: Potron G , LaFaurie M , Droulle C
Published: July 2018

We have tried to realize a compared study of enzymes in coagulation and fibrinolysis in vertebrates; by using different synthetic chromogen substrates with kinetic measurements and determination of Michaelis constant according to Linewear and Burk (Km).

Different species have been used in each class: two fishes,one amphibian, two birds, five mammals.

“Thrombin-like” activity, released by Echis Carinatus venom, measured on Chromothrombin* Stago, is found constantly in mammals with a Km close to that of man, but weak in birds and not at all in fish.

“Factor Xa-like” activity released by Russel viper’s venom, measured on S 2222 (Kabi) is found in all mammals and birds with a homogenous Km.

“Kallikrein-like” activity determined on S 2302 (Kabi) after activation at 4°C by dextran, is weak in all animals.

“Plasmin-like” activity measured on S 2251 (Kabi) after activation by Urokinase, is found again in all animals except frogs. All Km are homogenous except in dogs and birds.

Two inhibitors have been studied in heterologous systems towards human thrombin and plasmin, and are found at a constant rate close to that of man, for antithrombin; and at more variable rates for total antiplasmin activity.
Partial Characterization Of An Igm Ciroiating Anticqagu- Lant In A Patient With Systemic Scleroderma
Authors: Hauert J , von Felten A
Published: July 2018

All coagulation tests, utilizing phospholipids, were found to be prolonged in the plasma of a 71 year old wcman with systemic scleroderma. Hie patient had no spontaneous bleeding manifestations and underwent eye surgery for cataract without complications. Thrcmbin time and fibrinogen concentration were normal. Coagulation tests, performed with partial thromboplastin (APTT, factors VIII-XII), were more prolonged than those done with regular tissue thromboplastin (one-stage prothrombin time, factors II, V, VII, X). The addition of 1 part of the patient’s plasma (PP) to 99 parts of normal plasma (NP) resulted in a prolongation of the APTT from 34" to 49". No decrease of the anticoagulant activity (AA) was observed when freshly prepared intact platelets were incubated with the PP. However, incubation of PP with platelets, which had been 5 × frozen and thawed or incubated for 90 min in the presence of kaolin, partially neutralized AA.

When the patient’s serum was fractionated on Bio-Gel A-5m, all the inhibitory activity was found in the IgM peak. The AA of the purified IgM fraction was quenched after incubation with an anti-IgM antiserum, but not with anti-IgA or anti-IgG. Incubation of the IgM fraction with stored washed human platelets also led to partial neutralization of the AA. The patient’s IgM adsorbed to lysophosphatidylserine, which had been coupled to octyl-Sepharose, but did not fix complement when incubated with phospholipid micelles consisting of phosphatidylserine-phosphatidylcholine (1:1) and cholesterol in excess.

The absence of any bleeding manifestation in this patient; despite the presence of an extremely potent inhibitor against phospholipids, may be explained by the nonreactivity of the IgM inhibitor with fresh intact platelets.
The Effect Of Low Dose Intravenous Heparin On Anti-Factor Xa And Antithrombin III
Authors: Jennings S A , Heather B P , Greenhalgh R M
Published: July 2018

Preoperative blood samples from 17 patients undergoing major abdominal surgery were examined by the thrombelasto-graph saline dilution test, which has previously been shown to be a predictor of the risk of early postoperative deep vein thrombosis (DVT)(Heather et al 1980). By this test 8 patients were predicted to be at low risk of developing a DVT and received no special prophylaxis. 9 patients were considered to be at risk and were treated with a subcutaneous dose of 1000 units of heparin with the premedication together with a low dose of intravenous heparin infusion from the induction of anaesthesia until 2 hours after operation. Plasma antithrombin III (ATIII) concentration and anti-factor Xa activity were measured preoperatively, on day 1 and on day 3. No early DVT occurred, as assessed by I125 fibrinogen scanning, in either the untreated low risk patients or in the high risk patients receiving heparin infusion. The high risk patients had lower levels of ATIII before operation than the low risk patients (75±9%; 98±39%) and significantly lower levels on day 3 (64±25%; 106±34% p<0.02). However, these lowered levels of ATIII appeared in the high risk group to be augmented by the significant increase in anti-factor Xa activity 127±64%. before operation, 217±89%, on day 1 (p<0.02). Furthermore, on day 3 the high risk patients had significantly greater activity than those patients in the low risk group (212±76%; 106±34% p<0.02).

These results show that those patients at risk of developing a postoperative DVT had a significantly enhanced activation of anti-factor Xa, as a result of intravenous low dose heparin with the subsequent abolition of early venous thrombosis.
Low Molecular Weight Heparins: Anti-Xa/Aptt And Platelet Aggregation
Authors: Fussi F , Smith M R , Girolami A , Visentini L , Fabris F
Published: July 2018

Porcine mucosal Heparin (mean molecular weight= 15.000 Dalton) has been chemically depolymerized in presence of peroxides and N-sulphate groups have been re-introduced by reaction with sulpho- trioxides of amines. The depolymerization has been stopped at different times and the products are essayed for Anti-Xa, APTT and their ratio. A rise in the ratio Anti-Xa/APTT has been observed.

In order to check for an activity on the platelet aggregation, two sets of experiments have been carried out: in a first model, the 5-hydroxytrip- tamine (5-HT) release has been measured after addition of different quantities of products to washed platelets. One commercil Heparin gave a significant rise in 5-HT release whereas a normal porcine mucosal Heparin did not show any modification in basal values, nor significant modifications have been observed for low molecular weight heparins (10.000 to 7.000 D). Heparansulphate (HS) and Dermatansulphate (DS) show a slight anti-aggregating activity in this test.

In a second model, the percentage inhibition in collagen induced platelet release has been measured in a platelet rich plasma (PRP). All the tested heparins show a very significant inhibition, whereas HS and DS have no inhibiting activity in this test.
Prevalence of Protein C Deficiency in the Healthy Population
Authors: Tait R C , Walker Isobel D , Reitsma P H , Islam S I A M , McCall Frances , Poort S R , Conkie J A , Bertina R M
Published: July 2018

Reported prevalence rates for protein C (PC) deficiency in the population at large have varied widely. The differences presumably reflect the existence of an apparently high number of clinically recessive forms of the deficiency. In an attempt to document more precisely the prevalence of PC deficiency in the healthy population we have measured PC activity in just under 10,000 blood donors in the West of Scotland. After repeat testing of donors with low results and then further observation and selection, 32 donors were identified who had individual mean PC activities below the age- and gender-specific study reference range. Assessment of available first degree relatives, and also PC gene analysis in 23 of these donors, allowed identification of at least 14 with an inheritable deficiency (8 by both family study and gene analysis, 3 by family study alone and 3 by gene analysis alone). Two recurring and seven unique point mutations, only one of which has been previously described, were identified. The observed prevalence of inherited PC deficiency was 1.45 per 1000 (95% Cl, 0.79/1000 to 2.43/1000). However after correcting for the possibility of missing some genuine inherited deficiencies we estimated the prevalence to be as high as 1 in 500. All cases of hereditary deficiency were asymptomatic with regard to thrombosis and none had a strong family history of thrombosis. These findings confirm the rather frequent occurrence of asymptomatic individuals with PC deficiency and support the hypothesis that additional defects in the anticoagulant pathways may be required to confer a high-thrombotic-risk phenotype.
Effect of an Impermeant Arginine-Modifying Reagent on the Responses of Rabbit Platelets to Agonists
Authors: Anderson Esther R , Au-Young Yum-Kin , Foulks James G
Published: July 2018

The importance of surface arginyl residues in platelet aggregation was investigated by studying the effects of an impermeant arginine-modifying reagent, p-sulfonylphenylglyoxal (PSPG), on platelet responses to various agonists. Pretreatment of resuspended rabbit platelets with 2-15 mM PSPG resulted in complete inhibition of aggregation responses to ADP and 5-HT, and a concentration-dependent inhibition of the preceding shape change. Aggregation responses to thrombin also were inhibited in a concentration-dependent manner. The protective effects of antagonists of these three agonists (P, y-methylene ATP forADP, hirudin for thrombin and phentolamine for 5-HT) during pretreatment of platelets with PSPG indicated that intact arginine residues form part of the receptor sites for ADP and for thrombin. Arginine residues are not part of the 5-HT receptor site itself, but seem to be important for the maintenance of the functional integrity of this site.
The Functional Defect of Factor VIII Leiden, a Genetic Variant of Coagulation Factor VIII
Authors: Mertens K , van Wijngaarden A , Bertina R M , Veltkamp J J
Published: July 2018

Factor VIII Leiden is a genetic variant of coagulation factor VIII which has been detected in the plasma of a patient with mild haemophilia A. In this patient’s plasma factor VIII procoagulant antigen was in 5-fold excess over factor VIII procoagulant activity, indicating the presence of an abnormal factor VIII molecule. The variant factor VIII was isolated from the patient’s plasma, and its functional properties were studied in a factor X-activating system consisting of purified components. The isolated factor VIII Leiden was normally activated by factor Xa and by thrombin, but the activity of the factor Villa was about 3% of normal. The defect of factor Villa Leiden was studied by comparison with normal factor Villa in kinetic experiments of factor Xa formation. The results support the hypothesis that factor Villa Leiden has a reduced affinity for phospholipid-bound factor IXa in the intrinsic factor X-activating complex.
Platelet Suruival and Function in Rats with Enhanced Thrombotic Tendency
Authors: Delaini Federica , Dejana Elisabetta , Reyers Ine , Vicenzi Elisa , Vitti Germana De Bellis , Poggi Andreina , Donati Maria Benedetta
Published: July 2018

We have investigated the relevance of some laboratory tests of platelet function in predicting conditions of thrombotic tendency. For this purpose, we studied platelet survival, platelet aggregation in response to different stimuli, TxB2 and 6-keto-PGFlα production in serum of rats bearing a nephrotic syndrome induced by adriamycin. These animals show a heavy predisposition to the development of both arterial and venous thrombosis. The mean survival time was normal in nephrotic rats in comparison to controls. As to aggregation tests, a lower aggregating response was found in ADR-treated rats using ADP or collagen as stimulating agents. With arachidonic acid (AA) we observed similar aggregating responses at lower A A concentrations, whereas at higher AA concentrations a significantly lower response was found in nephrotic rats, despite their higher TxB2 production. Also TxB2 and 6-keto-PGFlα levels in serum of nephrotic rats were significantly higher than in controls. No consistent differences were found in PGI2-activity generated by vessels of control or nephrotic rats.

These data show that platelet function may appear normal or even impaired in rats with a markedly increased thrombotic tendency. On the other hand, the significance of high TxB2 levels in connection with mechanisms leading to thrombus formation remains a controversial issue.
Utilidad de la ecografía Doppler color en el seguimiento de la angioplastia carotídea
Authors: Surur Alberto M. , Crespo Germán , Galindez Jorge A. , Pessini Lucas , Marangoni Marco A. , Londero Hugo F.
Published: July 2018

Los ataques cerebrovasculares (ACV), representan un problema mayor en salud y son una causa importante de discapacidad en todo el mundo. La estenosis u oclusión carotídea aterosclerótica causa alrededor del 20% de las isquemias cerebrovasculares.1 Los ACV en los enfermos con estenosis carotídea se producen, en la mayoría de los casos, por la aparición de embolismos distales de trombo formado en la placa, oclusión trombótica aguda debido a rotura de la placa, o bien secundarios a las alteraciones hemodinámicas atribuibles a la estenosis, la cual produce disminución de la perfusión cerebral por el hipoflujo, en casos de estenosis críticas o suboclusivas. El tratamiento de la patología carotídea ha evolucionado de forma considerable a lo largo de los últimos años. Existen dos tratamientos invasivos para la estenosis carotídea significativa, que consisten en el abordaje quirúrgico con endarterectomía o tratamiento por vía percutánea con angioplastia y colocación de stent. En nuestra institución se realizaron, en el periodo comprendido entre marzo de 2013 y junio de 2017, aproximadamente 100 angioplastias carotídeas con colocación de stent. Todas fueron valoradas con ecografía Doppler color (EDC) al mes, a los seis meses y al año (en casos no complicados). En esta revisión bibliográfica es nuestra intención desarrollar las indicaciones, aplicaciones, hallazgos normales y patológicos en el examen de EDC en la evaluación de un paciente con stent carotídeo.
Case Report: A New Spectroscopy Finding in Infantile Neuroaxonal Dystrophy
Authors: Martin Andrew , Jamali Saharwash , Redhead Natasha , Armitage Paul , Desurkar Archana , Connolly Daniel J. A.
Published: July 2018

Infantile neuroaxonal dystrophy (INAD) is a rare autosomal recessive disorder that is associated with developmental delay and regression. A female patient of consanguineous parents presented with gross motor delay at 15 months. She was known to have two paternal uncles who had died with a diagnosis of INAD. Over the next 15 months, she exhibited regression in several domains and following genetic testing was diagnosed with a PLA2G6 mutation in keeping with INAD. The cerebellar vermis demonstrated a significant reduction in the N-acetylaspartate/creatinine (NAA/Cr) ratio of 0.69. This case highlights what we believe to be a new imaging feature of a low NAA/Cr ratio in the cerebellar vermis with normal ratios in the cerebellar hemispheres and basal ganglia in a patient with genetically confirmed diagnosis of INAD.
Immediate Unilateral Breast Reconstruction using Abdominally Based Flaps: Analysis of 3,310 Cases
Authors: Simpson Andrew , Ye Xiangyang , Tatro Eric , Agarwal Jayant , Kwok Alvin
Published: July 2018

Background The abdomen is the most common area from which tissue is harvested for autologous breast reconstruction. We sought to examine national data to determine the differences in total hospital charges, length of stay (LOS), and early postoperative complications following pedicled transverse rectus abdominis myocutaneous flap (pTRAM), free TRAM (fTRAM), deep-inferior epigastric perforator (DIEP), and superficial inferior epigastric artery perforator (SIEA) flaps.

Methods The 2009–2013 Nationwide Inpatient Sample Database was used to identify patients who underwent a unilateral mastectomy and only one type of abdominally based autologous flap (pTRAM, fTRAM, DIEP, and SIEA) during the same hospital admission. Outcomes of interest included total charges, LOS, and complications including revision of vascular anastomosis and hematoma.

Results A total of 3,310 cases were identified, corresponding to 15,991 abdominally based unilateral immediate breast reconstructions after standard weighting was applied; 5,079 (31.8%) were pTRAM flaps, 4,461 (27.9%) were fTRAM flaps, 6,206 (38.8%) were DIEP flaps, and 245 (1.5%) were SIEA flaps. The mean total charges for pTRAM, fTRAM, DIEP, and SIEA flaps were $17,765.5, $22,637.6, $25,814.6, and $26,605.2, respectively (p < 0.0001). The mean LOS for pTRAM, fTRAM, DIEP, and SIEA flaps were 96.5, 106.5, 106.7, and 108.9 hours, respectively (p = 0.002). The rates for return to the OR for the revision of a vascular anastomosis for pTRAM, fTRAM, DIEP, and SIEA were 0.0%, 1.72%, 2.66%, and 5.64%, respectively (p < 0.0001).

Conclusions There is variation in the total charges, LOS, and early complications between pTRAM, fTRAM, DIEP, and SIEA flap-based breast reconstruction. fTRAM, DIEP, and SIEA flaps incur higher hospital total charges, have longer lengths of stay, and experience more immediate complications compared with pTRAM. Well-designed prospective trials are required to better understand the findings from this study with the inclusion of other critical outcomes such as patient satisfaction, aesthetic results, and long-term outcomes such as abdominal wall morbidity.
Long-Term Outcomes after Double Free Flap Reconstruction for Locally Advanced Head and Neck Cancer
Authors: Brinkman J. , Kambiz Shoista , de Jong Tim , Mureau Marc
Published: July 2018

Background The use of simultaneous, multiple free flaps has become a reliable reconstructive option in patients with extensive composite defects after resection of locally advanced head and neck cancer. However, some reluctance remains among reconstructive surgeons with concerns regarding flap outcomes and limited patient survival. Therefore, we evaluated complications, long-term patient survival, and patient-reported outcomes following these extensive head and neck reconstructions.

Methods All consecutive patients treated with multiple free flaps for reconstruction of extensive composite defects after resection of locally advanced head and neck cancer between 1999 and 2014 were retrospectively reviewed. Patient charts were evaluated for demographics, treatment details, complications, and patient survival. In addition, all patients alive at the start of the study were asked to complete the 10-item Eat Assessment Tool (EAT-10) and the Intelligibility Rating Scale (IRS).

Results Eighty-four simultaneous, multiple free flaps were performed in 42 patients. The predominant free flap combination consisted of a fibula with either an anterolateral thigh (n = 22) or a radial forearm flap (n = 14). Complete flap survival was 95%. Nineteen patients were still alive with a mean follow-up of 55 months. Five-year patient survival was 46.3%. Mean EAT-10 score was 8.4 (range: 0–29), with only one patient reporting problematic swallowing. Ninety percent of the patients had moderate to good speech intelligibility with the IRS.

Conclusion Multiple, simultaneous free flaps can be performed safely, leading to acceptable long-term patient survival and patient-reported functional outcomes. Our study demonstrates that it is worthwhile to perform these challenging microvascular reconstructions in patients with locally advanced head and neck cancer.
The influence of hohlraum dynamics on implosion symmetry in indirect drive inertial confinement fusion experiments
Authors: Ralph J. E. , Landen O. , Divol L. , Pak A. , Ma T. , Callahan D. A. , Kritcher A. L. , Döppner T. , Hinkel D. E. , Jarrott C. , Moody J. D. , Pollock B. B. , Hurricane O. , Edwards M. J.
Published: July 2018

High laser energy (>1.2 MJ) implosion experiments on the National Ignition Facility show that low mode implosion symmetry is highly dependent on an expanding high-Z wall “bubble” plasma feature. The bubble is caused by the early time deposition of laser beams incident on the interior near the entrance of the cylindrical hohlraum (outer cone beams). It absorbs beams designated for the waist of the hohlraum (inner cone beams) causing a redistribution of x-ray flux on the capsule. From measurements, we are able to quantify the absorption and expansion of this bubble. Measurements show that the resulting hot spot is more oblate when there is more inner beam absorption in the bubble. We find absorption in the bubble to be between 51 ± 3% and 62 ± 2%. This bubble absorption is found to evolve predictably as a function of the early time outer cone laser pulse fluence and the pulse length. From this, a phenomenological model of the effective drive symmetry and subsequent implosion shape is found indicating a very strong dependence of implosion shape on early time laser fluence and laser pulse duration.
Printed, 1 V electrolyte-gated transistors based on poly(3-hexylthiophene) operating at >10 kHz on plastic
Authors: Zare Bidoky Fazel , Hyun Woo Jin , Song Donghoon , Frisbie C. Daniel
Published: July 2018

Electrolyte-gated transistors (EGTs) based on poly(3-hexylthiophene) (P3HT) offer low voltage operation, high transconductance, good operational stability, and low contact resistance. These characteristics derive from the massive electrochemical or double layer capacitance (∼10–100 μF/cm2) of the electrolyte layer that serves as the gate dielectric. However, electric double layer (EDL) formation at the source/electrolyte and drain/electrolyte interfaces results in significant parasitic capacitance in EGTs which degrades dynamic switching performance. Parasitic capacitance in EGTs is reduced by covering the top surfaces of the source/drain electrodes with a low-ĸ dielectric (∼0.6 nF/cm2). The low-ĸ dielectric blocks EDL formation on the electrode surfaces that are in direct contact with the gate electrolyte, reducing the parasitic capacitance by a factor of 104 and providing a route to printed P3HT EGTs on plastic operating at switching frequencies exceeding 10 kHz with 1 V supply voltages.
Communication: Random-phase approximation excitation energies from approximate equation-of-motion coupled-cluster doubles
Authors: Berkelbach Timothy C.
Published: July 2018

The ground-state correlation energy calculated in the random-phase approximation (RPA) is known to be identical to that calculated using a subset of terms appearing in coupled-cluster theory with double excitations (CCD). In particular, for particle-hole (ph) RPA this equivalence requires keeping only those terms that generate time-independent ring diagrams, and for particle-particle (pp) RPA it requires keeping only those terms that generate ladder diagrams. Here I show that these identities extend to excitation energies, for which those calculated in each RPA are identical to those calculated using approximations to equation-of-motion coupled-cluster theory with double excitations (EOM-CCD). The equivalence requires three approximations to EOM-CCD: first, the ground-state CCD amplitudes are obtained from the ring-CCD or ladder-CCD equations (the same as for the correlation energy); second, the EOM eigenvalue problem is truncated to the minimal subspace, which is one particle + one hole for ph-RPA and two particles or two holes for pp-RPA; third, the similarity transformation of the Fock operator must be neglected, as it corresponds to a Brueckner-like dressing of the single-particle propagator, which is not present in the conventional RPA.
Measuring third-order susceptibility tensor elements of monolayer MoS2 using the optical Kerr effect method
Authors: Liu Fang , Zhao Xin , Yan Xiao-Qing , Xin Xiufeng , Liu Zhi-Bo , Tian Jian-Guo
Published: July 2018

We present a femtosecond optical heterodyne detection of the optical Kerr effect study on Chemical Vapor Deposition-grown monolayer MoS2 films at 800 nm. The third-order nonlinear optical susceptibility (i.e., χxxyy(3)+χxyyx(3)) of monolayer MoS2 is determined to be 1.4 × 10−9 esu, and the ultrafast temporal response process indicates that the susceptibility origins from nonresonant electronic polarization. Based on Kleinman symmetry, susceptibility tensor elements are determined, and further, the nonlinear refractive indexes of any elliptically polarized light could be calculated for MoS2. These results will benefit the application of MoS2 in nonlinear photonic devices.