摘要:

Heavy water (D2O) is able to activate or to inhibit biological systems and thus influences metabolism and functions of tissues and organs. On the basis of results obtained in preservation experiments performed on various organs, the effects of D2O on the functions of human platelets (retraction, spreading, aggregation induced by adrenaline, ADP and collagen) have been investigated. The effects of D2O, involving changes of membrane receptor conformation, binding strength of substances to their specific receptors, pH-values or enzyme activities, resulted in a significant decrease of ADP- and collagen-induced aggregation, while adrenaline-induced aggregation was significantly increased at the same D2O concentration. Retraction in the presence of D2O was significantly inhibited in a dose-related manner, while spreading was diminished, but not fully inhibited even by highest concentrations of D2O (95%).

ISSN:1424-8832    

DOI:10.1159/000215138

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The inhibitory effects of 6-amidino-2-naphthyl-4-guanidinobenzoate·dimeth-anesulfonate (FUT-175) on the human Hageman factor fragment (HFf), factor Xa, thrombin, plasma kallikrein, and plasmin were studied. FUT-175 inhibited plasma kallikrein most (IC50 = 3.0 × 10-9M), followed by HFf (IC50 = 3.3 × 10-7M). FUT-175 was found to have an anticoagulant effect in the APTT and PT assay systems of human plasma. The concentration of FUT-175 for twofold increase in the clotting time in the APTT assay system was 5 × 10-7M.

ISSN:1424-8832    

DOI:10.1159/000215139

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Fibrin clot retraction (FCR) and collagen gel retraction (CGR) were studied in patients with inherited platelet defects, i.e. in Glanzmann’s thrombasthenia, Hermansky-Pudlak syndrome, May-Hegglin anomaly, giant platelet syndrome, as well as in patients with von Willebrand disease and factor XIII deficiency. FCR was abnormal only in thrombasthenia, while CGR was found to be reduced in 2 patients with Hermansky-Pudlak syndrome and in 4 out of 5 cases with von Willebrand disease. Both FCR and CGR were normal in May-Hegglin anomaly, giant platelet syndrome and severe factor XIII deficiency. In none of the examined bleeding disorders was a concomitant FCR and CGR reduction detected. Natural polyamines and anti-fibronectin antibodies did not affect platelet potency in FCR or CGR. Peroxidation of platelet membrane components by sodium periodate abolished the platelet-induced FCR and CGR. This effect was reversed by subsequent reduction by sodium borohydrid

ISSN:1424-8832    

DOI:10.1159/000215140

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The effect of granulocytes on human platelet aggregation was investigated in vitro. Platelet function was assayed by photometric technique. Incubation of platelets with latex-stimulated granulocytes for 1 h at room temperature resulted in total inhibition of arachidonic acid-induced platelet aggregation. ADP-induced platelet aggregation was suppressed, lacked secondary wave and was pursued by swift disaggregation. Platelet aggregates induced by collagen dispersed faster under the influence of stimulated granulocytes. The present results indicate that granulocytes may play a role in the hemostatic mechanism in man.

ISSN:1424-8832    

DOI:10.1159/000215141

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Thrombocytopoietin seems to be only partially responsible for the regulation of platelet production. We determined precisely the differences between a second thrombocytopoiesis-stimulating factor (TSF2), and thrombocytopoietin (TSF1) and erythropoietin (Epo). Fractionation was carried out, first on a DEAE-cellulose phosphate column and then on a Sephadex G-75 column. Thrombocytopoietic activity in the various fractions was assessed using 75Se-methionine platelet incorporation into normal recipients. Epo concentrations were determined using a radioimmunoassay. We showed that the apparent molecular weight of TSF2 is 14,000 daltons. It differs from TSF1 (48,000 daltons) and from Epo (39,000 daltons). For doses of 8–12 mU Epo/rat, found in whole serum injected, no effect on thrombocytopoiesis was found. On the contrary, a significant effect (p < 0.01) was found when the same quantities of Epo present in the Sephadex G-75 F4’ fraction were injected (2–10 mU/rat). TSF2 can be separated from TSF1 and Epo, using biochemical techn

ISSN:1424-8832    

DOI:10.1159/000215142

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

The role and effect of added lys-plasminogen (lys-PLG) on urokinase-induced thrombolysis in an in vitro biphasic system were investigated. The kinetics of lysis of whole blood thrombi was followed in perfusion mediums of normal plasma, PLG-deficient plasma and normal saline using a high and a low concentration of urokinase (UK). The lysis of standard whole blood thrombi in whole blood perfusion mediums to which had been added UK alone or UK plus lys-PLG was compared to whole blood thrombi enriched with lys-PLG by incorporation during thrombus formation or by adsorption during perfusion. In addition, the kinetics of lysis of PLG-deficient fibrin thrombi perfused in PLG-deficient plasma or normal saline was studied when lys-PLG had been added to the thrombus, to the perfusion medium or to both thrombus and medium. In PLG-deficient plasma from which plasmin inhibitors had not been removed, thrombolysis was minimal even at a high concentration of UK. This effect could be neutralized, and to some extent, regulated, by lys-PLG enrichment of the medium. Both PLG-incorporated and PLG-adsorbed whole blood thrombi gave initial and sustained acceleration of UK-induced lysis in comparison with standard nontreated thrombi. It is concluded that in a blood-thrombus biphasic thrombolytic system induced by UK, there is interaction between the phases, and that PLG in both phases influences thrombolysis.

ISSN:1424-8832    

DOI:10.1159/000215143

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Inhibition reference curves for α2-antiplasmin showed a deviation from linearity at low inhibitor concentrations using the chromogenic substrate S-2251. Extrapolation of these curves to zero inhibition gave higher amidolytic activities than actually recorded with the free enzyme plasmin. It was further found that comparison of purified α2-antiplasmin and that in plasma was prevented by the deviation. The difference between calculated and measured plasmin activity could not be attributed to instability of plasmin. It was established that the observations (1) were specific for high concentrations of S-2251, (2) were not the same with another plasmin substrate, chromozym PL, and (3) were related to the addition of plasma proteins. Apparently, the problem was related to the solubility state of S-2251. A solution to this problem is the addition of nonionic detergents, notably Tween 80 (0.01%) or Triton X-100 (0.03%), which prevent all deviation

ISSN:1424-8832    

DOI:10.1159/000215144

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Non-steroidal anti-inflammatory drugs are theoretically contra-indicated in the haemophilias but might be useful for those patients with chronic arthritic pain, as long-term strong analgesics are also undesirable. We carried out studies of platelet function and coagulation in 8 normal controls and 7 haemophiliacs while they were taking sequentially benoxaprofen and salsalate. No significant alterations in platelet function, bleeding time or coagulation occurred with either drug. In a subsequent double-blind controlled clinical trial using ibuprofen and placebo 8 of 9 patients had a significant reduction in pain score whilst using ibuprofen without significant change in the frequency of bleeds or the amount of concentrate used. Laboratory measures of coagulation also failed to reveal any adverse effect of the active drug. Non-steroidal anti-inflammatory drugs may be beneficial and may be used with caution in haemophilia.

ISSN:1424-8832    

DOI:10.1159/000215145

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

Hepatic blood flow (HBF) has been reported to reflect liver cell mass. HBF was studied in 21 patients with chronic active hepatitis (CAH) and in 20 patients with liver cirrhosis (LC). It was correlated with such indices of liver protein synthesis as serum albumin, Normotest, plasma activity of antithrombin III, prekallikrein, α2-antiplasmin and plasminogen. No correlation between HBF and the examined parameters was seen in CAH. HBF correlated with all the indices of liver protein synthesis in LC, thus suggesting that serum albumin, antithrombin III, Normotest, prekallikrein, plasminogen, and α2-antiplasmin could reflect the residual liver cell mass in L

ISSN:1424-8832    

DOI:10.1159/000215146

出版商:S. Karger AG    

年代:1985

数据来源: Karger

摘要:

A 12-year-old girl with lifelong hemorrhagic episodes was found to have both a dys-form of homozygous factor XI deficiency and heterozygous factor XII deficiency. The heredity of the coagulation defects was confirmed by family studies. Severe bleeding after dental surgery occurred in spite of replacement therapy and local measures including fibrin glue. Our findings suggest that the risk of bleeding in patients with homozygous factor XI deficiency must not be underestimated and that the most effective measure is the transfusion of sufficient amounts of fresh frozen plasma until at least the 5th postoperative day.

ISSN:1424-8832    

DOI:10.1159/000215147

出版商:S. Karger AG    

年代:1985

数据来源: Karger