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The clinical significance of diminished protein Z in plasma is controversial. Studies in mice demonstrated that deficiency of protein Z dramatically increases the prothrombotic tendency of factor V Leiden mutation. This finding was confirmed by initial results in humans, indicating that thromboembolism in factor V Leiden patients with lowered protein Z level occurs earlier than in patients with normal protein Z levels. Consequently, the aim of our present study was to find out whether genetic alterations of protein Z were demonstrated in patients with factor V Leiden mutation and early onset of thromboembolic disease. DNA-sequencing of the protein Z gene was performed in two patients with factor V Leiden mutation, early onset of thromboembolism, and lowered protein Z levels. In both patients, R255H substitution of the protein Z gene was identified. Subsequently, the R255H substitution was also found in 12 of 132 additional patients. Patients presenting with the R255H substitution in addition to factor V Leiden mutation showed thromboembolic events more frequently than factor V Leiden patients without R255H substitution of the protein Z gene. In conclusion, R255H substitution of the protein Z gene seems to influence clinical symptoms of thromboembolism in factor V Leiden patients.

Protein Z enhances the inhibition of factor Xa by protein Z-dependent protease inhibitor (ZPI). Thus, diminution of protein Z should induce prothrombotic tendency due to lowered cofactor activity for ZPI. In Factor V Leiden mice, prothrombotic tendency of severe diminution or lack of protein Z was demonstrated. We here present first studies in humans, indicating that diminution of protein Z in factor V Leiden patients aggravates thromboembolic risk.

Protein Z is a vitamin K-dependent protein. The first cases of protein Z deficiency were described in patients suffering from a bleeding tendency from otherwise unknown origin. Today, diminutions of protein Z seem to play a role not only in bleeding patients but also in patients with factor V Leiden mutation: Patients presenting with factor V Leiden mutation and low protein Z levels show earlier onset and higher frequency of thromboembolic events than do patients presenting with factor V Leiden mutation and normal protein Z levels. Thus, protein Z is a good example for the--at first sight--paradox action of coagulation proteins.

Background: Thromboembolism remains a major problem in patients scheduled for craniotomy. The present study examined parameters of coagulation and fibrinolysis in 15 patients undergoing elective craniotomy in the perioperative period., Methods: Plasma concentrations of thrombin antithrombin III complex (TAT), prothrombin fragment 1 + 2 (F1 + 2), and d-dimer were measured before and after induction of anesthesia, 60 minutes and 180 minutes after the beginning of surgery, and on the first postoperative morning., Results: TAT, a marker of activation of coagulation, increased significantly (p < 0.05) from the preoperative measurements to the data obtained 60 minutes after beginning the surgery, reaching a maximum of 180 minutes after the start of surgery. F1 + 2, also indicating activation, showed a similar concentration time course with an intraoperative maximum. D-dimer, a marker of fibrinolysis, tended to increase slightly beginning 180 minutes after surgery with a maximum on the morning after surgery. Statistical significance for F1 + 2 and d-dimer was not found., Conclusions: This study showed a transient activation of coagulation with an intraoperative maximum in patients undergoing craniotomy. This result could be due to a liberation of thromboplastin from brain tissue.

Intracranial surgery is often complicated by thromboembolic events including the life-threatening pulmonary embolism. After head trauma and in patients with brain tumors disseminated intravascular coagulation (DIC) can occur, characterized by the triggering of the coagulation cascade and the depletion of coagulation factors which ultimately leads to bleeding. The identification of patients at high risk as well as the early diagnosis of hemostatic problems uses routine laboratory parameters such as partial thromboplastin time and prothrombin time reflecting the intrinsic and the extrinsic pathway of the coagulation respectively. Thrombin antithrombin III complexes (TAT) and prothrombin fragment 1 + 2 (F1 + 2) are further indicators of an activation of the coagulation whereas fibrinogen degradation products (FDP) refer to the fibrinolytic system. The basic principles of coagulation and fibrinolysis are summarized as well as the changes of laboratory parameters accompanying DIC, hypercoagulability and hyperfibrinolysis.

Protein Z is a vitamin K-dependent plasma protein, which promotes the association of thrombin with phospholipid surfaces. Deficiency states of protein Z have recently been shown in patients with a bleeding tendency of an otherwise unknown origin. In the present study severe diminutions of blood plasma protein Z were found in patients with chronic liver diseases. Protein Z levels decreased with increasing severity of liver disease. Strong correlations between protein Z and other plasma proteins of liver origin indicate that protein Z primarily originates from the liver. The cutaneous bleeding tendency in cirrhosis may in part be due to protein Z deficiency.

Protein Z is a vitamin K-dependent plasma protein synthesized by the liver. Protein Z promotes the association of thrombin with phospholipid surfaces. So far, nothing is known about the clinical relevance of protein Z except alterations measured in patients under oral anticoagulant treatment. We propose that in protein Z deficiency a bleeding tendency might result because of the interaction of protein Z with thrombin on phospholipid endothelial surfaces. Therefore, we examined 36 patients with bleeding tendency of unknown origin, who were not under oral anticoagulant treatment and had normal liver synthesis function. Mean protein Z value of the patients with bleeding tendency was significantly diminished in comparison to the healthy control group. Twenty-one of the bleeding patients had lower protein Z levels than the lowest protein Z level of the control group. In conclusion, protein Z deficiency is described as a new type of bleeding tendency.

In liver disorders alterations of the coagulation system are mainly due to a reduced synthesis of coagulation proteins. In addition, an enhanced intravascular consumption of coagulation factors is discussed controversely in liver diseases. By measuring factor IXiAT- and TAT-complexes we tried to find out, whether coagulation activation in liver patients leads to activation of the complete coagulation cascade followed by DIC or whether in some diseases a futile partial coagulation activation develops. In all liver diseases examined, elevated factor IXiAT-complexes were demonstrated, while TAT-complexes were only elevated in chronic active hepatitis, metabolic decompensated liver cirrhosis and in patients suffering from end stage liver disease. We conclude that all liver diseases examined lead to an activation of the coagulation cascade. A complete activation followed by DIC only occurs in patients with very severe liver disorders.

In this communication, we propose a method for the determination in human serum of fructose 1,6-bisphosphatase based on parallel measurements of enzyme activities in presence of 1-p-bromotetramisole oxalate and adenosine 5'-monophosphate. The employment of these specific inhibitors renders the discrimination between specific and non-specific activities feasible. A regression analysis identifies fructose 1,6-bisphosphatase (EC 3.1.3.11) as the origin of the specific and alkaline phosphatase (EC 3.1.3.1) as the source of the non-specific fructose 1,6-bisphosphate dephosphorylating activities. This procedure lends itself to the diagnosis using serum samples of 'piecemeal' necrosis in liver disease.

Blood glucose, serum insulin, C-peptide, free fatty acids and growth hormone were evaluated in 45 patients with histologically established hepatic steatosis after an oral glucose load (100 g). Glucose tolerance was impaired in 59 per cent of the patients. Significantly increased levels were found for blood glucose (fasting and after 60 and 120 min), insulin (after 60, 120 and 180 min), C-peptide (fasting and after 60, 120 and 180 min), and free fatty acids (fasting and after 60 and 120 min). Human growth hormone levels were not altered. After glucose administration the C-peptide/insulin ratio was significantly reduced in hepatic steatosis compared to controls. In patients with hepatic steatosis there were no differences between subjects with normal body weight or overweight nor between stadium I and stadium II ('alcoholic hepatic steatosis') concerning glucose, insulin, C-peptide, HGH and FFA levels in blood. We conclude, that hepatic steatosis is associated with relative insulin resistance to which elevated FFA may contribute. In addition, the decreased C-peptide/insulin ratios suggest an impaired hepatic insulin degradation as it was already described for more serious liver diseases.

The histomorphology of typical liver cell necroses are here correlated with heterotope distributions of enzymes in liver parenchyma. A variety of findings indicate a congruence between gluconeogenetic areas of the liver and the typical pattern of 'piecemeal' necrosis. We therefore propose a diagnostic index based on fructose 1,6-bisphosphatase activity and the data from the clinical laboratory. This index makes it possible to distinguish between chronic persistent and chronic aggressive hepatitis.

Intoxication of male rats with 5 mg/kg parathion reduces survival to 15%. Diethyldithiocarbamate (DDC), known to inhibit mixed-function oxidase activity, has no effect on survival rate when this compound is used in a dosage of 300 mg/kg 45 min before or 10 min after parathion intoxication. However, when DDC and parathion are administered simultaneously, the rate of survival rises to 53%.

S protein/vitronectin plays an important role as a regulatory component in the terminal steps of the complement- and coagulation cascades. In patients suffering from chronic liver diseases, plasma S protein concentration was measured and compared with changes in serum cholinesterase activity, coagulation factor X activity and complement component C3 concentration. Significant decreases of all these proteins were seen in liver cirrhosis. Changes in S protein concentration correlated closely with those of cholinesterase, factor X and complement C3. The data give support for the liver as the main organ of plasma S protein/vitronectin synthesis.

Amatoxins were detected radioimmunologically as early as 90-120 min after ingestion in the gastric fluid and urine of a 15-year-old boy who tried to commit suicide by ingestion of wild mushrooms. This early detection of amatoxins in the urine is proof of rapid absorption from the intestinal tract and subsequent excretion by the kidneys in man.