[52-year-old patient with painful ascites following fall from a bicycle]. / 52-jähriger Patient mit schmerzhaftem Aszites nach Fahrradsturz.

A 52-year-old patient presented with a ruptured abdominal aortic aneurysm after bicycle trauma. He was treated with a vascular prosthesis. His postoperative recovery was complicated by acute renal failure with anuria for which he was commenced on dialysis. His main persistent symptoms were severe abdominal pain, nausea and vomiting as well as massive ascites. Despite several attempts of a diagnostic and therapeutic ascitic tap, we were initially unable to make a diagnosis. Following each attempted paracentesis, symptoms initially improved. Ascites did reaccumulate, however, and we had to continue with his dialysis. Measurement of creatinine in the ascitic fluid was the key to the correct diagnosis. The ascitic fluid creatinine was nearly 3 times higher than the serum creatinine. The consequent MRI scan of the abdomen with excretion urogram demonstrated a leakage of the left ureter at the junction of the proximal and the middle third of the ureter with contrast leaking into the surrounding fluid.

Should commercial organ donation be legalized in Germany? An ethical discourse.

OBJECTIVE: We evaluated the arguments pro and con concerning kidney sales from a German perspective. At present, we see social, medical, and ethical reasons why organ selling should not be legalized in Germany. DISCUSSION: Legalization of organ selling would weaken the principle of solidarity within the German health system. Conversely, profit making will undermine the principle of social justice. Within the present social system in Germany, there is no economic pressure to sell an organ to save life, and there is no medical need to buy a kidney. Also, there exists the risk that opening the market for organ sales will de-motivate potential directed organ donors. Relatives would have more doubts about giving their consent to donate organs of their deceased. Moreover, the historical experience with the "action T4" of the Nazi regime sensitized German society for the categorical imperative set forth by Immanuel Kant (1724-1804), namely that man is not a means, but an end to himself. By selling one's kidney, the donor uses himself as a means and as an instrument for the end result of gaining money. With directed organ donation, the welfare of the recipient is the end result. The pending reform of the German health system needs a more communitarian sense, which will be eroded should organs be sold and no longer donated as gifts. CONCLUSION: Germany's special historical experience and a deeply embedded consent toward ethical values give reason for the prohibition of organ selling in Germany.

Extracellular lipase from Pseudomonas aeruginosa is an amphiphilic protein.

Lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) secreted by Pseudomonas aeruginosa PAC1R was purified from cell-free growth medium by preparative isoelectric focusing. After blotting the N-terminal amino acid sequence and the amino acid composition were determined and compared to P. fragi and P. cepacia lipases yielding significant homology between all three species. Additionally, a consensus sequence K-Y-P-i-v-l-V-H-G was identified residing at the N-terminus of Pseudomonas lipases and in the central part of Staphylococcus lipases. Treatment of lipase with the serine-specific inhibitor diethyl p-nitrophenyl phosphate caused a rapid and complete inhibition of enzyme activity indicating the presence of a serine at the catalytic site as expected from lipase consensus sequences. Upon charge-shift electrophoresis the electrophoretic mobility of purified lipase was shifted either anodally or cathodally in the presence of sodium deoxycholate and cetyltrimethylammoniumbromide, respectively. This result demonstrates that extracellular lipase of P. aeruginosa exhibits an amphiphilic character like intrinsic membrane proteins.

Sulfonyl fluoride serine protease inhibitors inactivate RNK-16 lymphocyte granule proteases and reduce lysis by granule extracts and perforin.

Cytolytic granules purified from natural killer lymphocytes (NK) contain a pore-forming protein (perforin) and a number of serine proteases. When these proteases are inhibited by serine protease-specific isocoumarin reagents the serine proteases are inactivated and the cytolytic activity of the granules is decreased. Paradoxically, it has been found that the general serine protease inhibitor phenylmethylsulfonyl fluoride (PMSF) frequently cannot block killing even though it inhibits many of the serine proteases. At the same time it has been reported that "purified" perforin alone can lyze cells. To address these inconsistencies we first compared the ability of PMSF and four new sulfonyl fluoride serine protease inhibitors to inhibit proteases and cell lysis. We determined the effects on lysis and the second order inhibition rate constants for five granule protease activities: ly-tryptase, ly-chymase, Met-ase (methionine cleaving), Ser-ase (serine cleaving) and Asp-ase (aspartic acid cleaving). One compound, 2-(Z-NH(CH2)2CONH)C6SO2F, was a potent inhibitor of Met-ase activity (k(obsd)/[I] = 162 M-1 s-1), ly-chymase activity (k(obsd)/[I] = 147 M-1 s-1), and granule-mediated as well as perforin-mediated lysis. PMSF was a poor inhibitor of granule proteases (k(obsd)/[I]'s less than 7 M-1 s-1 for four activities and no inhibition of Ser-ase); the lack of reactivity is consistent with the failure of PMSF to block granule lytic activity. We also prepared enriched perforin by anion exchange chromatography and showed that a ly-chymase and a Met-ase associated with perforin. By inhibiting these proteases we also inhibited lytic activity.

Characterization, application and potential uses of biotin-tagged inhibitors for lymphocyte serine proteases (granzymes).

Cytotoxic lymphocytes and natural killer cells are able to kill their target cells in minutes. The death of the target cell occurs after the release of cytoplasmic granules from the effector cell. These granules contain the pore-forming protein perforin and serine proteases (granzymes). To date 10 genes encoding lymphocyte granzymes have been discovered; of these only four have been purified and characterized for their substrate specificity. Several are predicted to have a common chymase, like specificity which is found in the granule extracts. Others may need to be enriched as active enzymes before they can be evaluated for substrate hydrolysis. Due to the limitations of detection by substrate hydrolysis, a more sensitive method for the detection of dilute granules was needed. We report the differing reactivities of seven biotin (Bi)-tagged isocoumarin (IC) inhibitors for Asp-ase, chymase, tryptase and Met-ase granzymes. The inhibitors contained different substituents at their no. 3 position: methoxy (OMe), ethoxy (OEt), propoxy (OPr) or 2-phenylethoxy (OEtPh) groups. The OMe group conferred general reactivity, whereas the OEtPh group conferred selective reactivity with chymase granzymes. The inhibitors that contained the longest aminocaproyl (Aca) spacers between the biotin-tag and the isocoumarin ring mediated the most stable granzyme inactivation. These inhibitors were the most effective at blocking lysis of red blood cells by the granule extracts. The inhibitors were used in protein blotting experiments where the biotin was detected with an avidin-enzyme complex. Over 10 granzymes were labelled by the inhibitor Bi-Aca-Aca-IC-OMe. The inhibitors detected granzymes when they were not readily detected by substrate hydrolysis.

Fractionation of perforin and granzymes by immobilized metal affinity chromatography (IMAC).

Cytotoxic lymphocytes and natural killer cells kill their targets by releasing pore-forming granules or by Fas ligand-Fas initiated death. The granules contain the pore-forming protein perforin, proteoglycan and multiple serine proteases termed granzymes. In this paper we describe two options for isolating perforin and granzymes. Both options separate the proteins by their ability to bind to immobilized metal affinity chromatography (IMAC) columns. The first option, with Cu2+ as the metal (Cu2+-IMAC), separates both perforin and granzymes while the second, with Co2+ as the metal (Co2+-IMAC), separates only perforin. After Cu2+-IMAC perforin is > 20-fold enriched with excellent recovery of lytic activity. Only two proteins are substantial contaminants. After Cu2+-IMAC, the perforin is dilute and requires concentration before additional steps of purification. The second option, with Co2+ as the metal Co2+-IMAC), yields perforin that is concentrated in a sharp peak. The concentrated perforin is immediately suitable for further purification. The first option, with Cu2+, isolates the granzymes while the second option, Co2+-IMAC, does not. After isolation, the perforin lytic and granzyme activities are stable for weeks at 4 degrees C, an advantage to previous isolation methods for these proteins. The excellent recoveries of perforin and granzymes also indicate that these proteins are less than 4% and 15% of the total lymphocyte granule protein, respectively.

Synthesis and evaluation of diphenyl phosphonate esters as inhibitors of the trypsin-like granzymes A and K and mast cell tryptase.

Thirty-six new amino acid and peptidyl diphenyl phosphonate esters were synthesized and evaluated to identify potent and selective inhibitors for four trypsin-like proteases: lymphocyte granzymes A and K, human mast cell tryptase, and pancreatic trypsin. Among five Cbz derivatives of Lys and Arg homologues, Z-(4-AmPhe)P(OPh)2 is the most potent inhibitor for granzyme A, and Z-LysP(OPh)2 is the best inhibitor for granzyme K, mast tryptase, and trypsin. The amidino P1 residue D,L-(4-AmPhGly)P(OPh)2 was utilized in a series of compounds with several different N-protecting groups and systematic substitutions at P2 in Cbz-AA derivatives and at P3 in Cbz-AA-Ala derivatives. Generally, these phosphonates inhibit granzyme A and trypsin more potently than granzyme K and tryptase. The P2 Thr and Ala dipeptide phosphonates, Cbz-AA-(4-AmPhGly)P(OPh)2, are the most potent inhibitors for granzyme A, and Cbz-Thr-(4-AmPhGly)P(OPh)2 (kobs/[I] = 2220 M-1 s-1) was quite specific with much lower inhibition rates for granzyme K and trypsin (kobs/[I] = 3 and 97 M-1 s-1, respectively) and no inhibition with tryptase. The most effective inhibitor of granzyme A was Ph-SO2-Gly-Pro-(4-AmPhGly)P(OPh)2 with a second-order rate constant of 3650 M-1 s-1. The most potent inhibitor for granzyme K was 3, 3-diphenylpropanoyl-Pro-(4-AmPhGly)P(OPh)2 with a kobs/[I] = 1830 M-1 s-1; all other phosphonates inhibited granzyme K weakly (kobs/[I] < 60 M-1 s-1). Human mast cell tryptase was inhibited slowly by these phosphonates with Cbz-LysP(OPh)2 as the best inhibitor (kobs/[I] = 89 M-1 s-1). The overall results suggest that scaffolds of Phe-Thr-(4-AmPhe) and Phe-Pro-Lys will be useful to create selective phosphonate inhibitors for granzymes A and K, respectively, and that P4 substituents offer opportunities to further enhance selectivity and reactivity.

Occlusive vascular diseases in oral contraceptive users. Epidemiology, pathology and mechanisms.

Despite being an unprecedented departure from normal physiology, the combined oral contraceptive is not only highly effective, but it also has a remarkably good safety record. Concerns over safety persist, though, particularly with regard to venous thromboembolism (VTE), stroke and myocardial infarction (MI). Epidemiological studies consistently show an increase in risk of VTE, but the results are more contentious with regard to arterial diseases. Despite 40 years of research, the mechanisms behind these adverse effects are not understood. In this review, we integrate information from published studies of the epidemiology and pathology of the occlusive vascular diseases and their risk factors to identify likely explanations for pathogenesis in oral contraceptive users. Oral contraceptives induce both prothrombotic and fibrinolytic changes in haemostatic factors and an imbalance in haemostasis is likely to be important in oral contraceptive-induced VTE. The complexity of the changes involved and the difficulty of ascribing clinical significance has meant that uncertainty persists. A seriously under-researched area concerns vascular changes in oral contraceptive users. Histologically, endothelial and intimal proliferation have been identified in women exposed to high plasma estrogen concentrations and these lesions are associated with thrombotic occlusion. Other structural changes may result in increased vascular permeability, loss of vascular tone and venous stasis. With regard to arterial disease risk, epidemiological information relating to dose effects and joint effects with other risk factors, and studies of pathology and changes in risk factors, suggests that oral contraceptive use per se does not cause arterial disease. It can, nevertheless, synergise very powerfully with subclinical endothelial damage to promote arterial occlusion. Accordingly, the prothrombotic effects of the oral contraceptive estrogen intervene in a cycle of endothelial damage and repair which would otherwise remain clinically silent or would ultimately progress - in, for example, the presence of cigarette smoking or hypertension - to atherosclerosis. Future work in this area should focus on modification of the effects of established risk factors by oral contraceptive use rather than modification of the supposed risk of oral contraceptive use by established risk factors. Attempts to understand vascular occlusion in oral contraceptive users in terms of the general features of VTE or with reference to atherosclerosis may be limiting, and future work needs to acknowledge that such occlusions may have unique features. Unequivocal identification of the mechanisms involved would contribute considerably to the alleviation of fears over vascular disease and to the development of even safer formulations.

An outer membrane protein characteristic of mucoid strains of Pseudomonas aeruginosa.

SDS-polyacrylamide gel electrophoresis of outer membrane (OM) proteins of different mucoid strains of P. aeruginosa revealed a protein of about 54 kDa that was absent in nonmucoid strains. This 54 kDa protein was expressed under iron-restricted and iron sufficient growth conditions. Electrophoretic mobility of the 54 kDa protein was modified by the solubilization temperature as well as by the addition of lipopolysaccharide and alginate prior to electrophoresis. Treatment of OMs with octylglucoside/KCl or SDS completely extracted the 54 kDa protein at low temperatures. The possible role of this protein in biosynthesis and/or excretion of bacterial alginate is discussed.

Influence on hormone levels, lipid metabolism and reversibility of endocrinological changes after leuprorelin acetate depot therapy.

The effect of leuprorelin acetate depot on the endocrine system and on lipid metabolism was evaluated in a multicentre, noncomparative study. During the first month of treatment, suppression of serum oestradiol levels to below 20 pg/ml was achieved and luteinising hormone and follicle-stimulating hormone levels were reduced to less than 50% of pretreatment values. A negative influence on lipid metabolism was not recorded. The high-density lipoprotein/low-density lipoprotein ratio did not change during therapy. Resumption of menstruation occurred within a mean period of 3 months after the last leuprorelin acetate depot injection.

Plasmatic haemostasis in gonadotrophin-releasing hormone analogue therapy: effects of leuprorelin acetate depot on coagulatory and fibrinolytic activities.

The plasmatic parameters of coagulatory and fibrinolytic activity were studied in 15 patients with biopsy-proven endometriosis treated with leuprorelin acetate for 6 months. Bleeding time remained constant, indicating the absence of increased bleeding tendencies. The activity of the main inhibitor of the fibrinolytic response, plasminogen activator inhibitor, was reduced by 25%, suggesting an improvement in fibrinolytic reactivity. Plasma levels of fibrin degradation fragments were reduced by 35%, suggesting a marked reduction in the rate of fibrin generation and degradation. A simultaneous reduction in thrombin-antithrombin III complexes and prothrombin fragment 1 + 2 (-10%) indicated that this effect was induced by reduced procoagulant activity, ie, thrombin generation. These data indicate that in gonadotrophin-releasing hormone (Gn-RH) analogue therapy the basal rate of coagulatory processes is reduced. The frequency and extent of fibrin-generating and degrading processes are reduced, suggesting a beneficial effect of Gn-RH analogues on the risk of thromboembolic disease.

Experience with leuprorelin acetate depot in the treatment of fibroids: a German multicentre study.

Between October 1988 and October 1990 in a noncomparative multicentre study, 114 patients were treated for uterine fibroids with the gonadotrophin-releasing hormone (Gn-RH) agonist, leuprorelin acetate depot. The mean age of the women was 33 years and 55.3% of them had a history of infertility. After confirmation of the diagnosis by ultrasound and/or operation, treatment began between day 1 and 3 of the cycle with leuprorelin acetate depot 3.75 mg subcutaneously. Therapy was carried out for a total of 6 months with one injection every 4 weeks. Treatment was paralleled by measurements of endocrine and metabolic parameters, estimation of myoma and uterine size by ultrasound and self-reporting of the patients of drug-related complaints. Four of the 114 women did not complete the whole treatment, two of them because of general side effects, one because of carcinophobia and unsatisfactory regression of the myoma and the last one for unspecified reasons. During treatment, a mean reduction of the uterine volume of about 67% was observed, in conjunction with shrinkage of the myoma in 92.1% of cases (mean decrease of 56% of the fibroids) with a large interindividual difference. Maximal diminution of uterine and fibroid size had been nearly completely reached within the first 12 weeks of therapy. After 4 weeks of the Gn-RH agonist depot most of the patients had achieved postmenopausal status, which continued throughout the remaining 20 weeks of treatment. In accordance with this finding, the majority of general side effects was due to the hypo-oestrogenic endocrine status. Liver and lipid metabolism was almost unaffected, although increasing calcium and alkaline phosphatase serum levels as well as an increased urinary calcium/creatinine ratio demonstrated an increased metabolic turnover of the bone. Haemoglobin concentrations, however, increased in those cases with fibroid-related anaemia. Thus the slow-release form of leuprorelin acetate is an adjunct to myomectomy especially in those women in whom family planning is not yet completed.

Treatment of endometriosis with leuprorelin acetate depot: a German multicentre study.

During the past decade, the development of various gonadotrophin-releasing hormone (Gn-RH) agonists, which induce reversible hypo-oestrogenism has opened a new area in the medical management of endometriosis. In an open, multicentre phase III study, the efficacy, tolerance and safety of the Gn-RH agonist leuprorelin acetate were tested. The preliminary results of 104 women treated in seven German centres are presented. Pelvic endometriosis was diagnosed by laparoscopy and classified according to the American Fertility Society scoring system: 33% of patients had minimal, 22% mild, 28% moderate and 8% severe endometriosis and in 9% no pathological results were obtained. The patients' mean age was 30 +/- 6 years and 66 had infertility problems. Treatment was started within the first 3 days of the menstrual cycle and consisted of a subcutaneous injection of leuprorelin acetate 3.75 mg, repeated once monthly over 24 weeks. A follow-up period of 12 months after the last injection has been completed in 70 patients, including a second laparoscopy. At all visits, symptoms were evaluated, physical examinations performed, and blood samples collected for haematological screening, serum chemistry determinations and measurement of the gonadotrophins oestradiol and progesterone and leuprorelin acetate. The median score at laparoscopy fell from 12 before operation to 8 after operation and 2 after treatment with leuprorelin acetate. Of the total number of patients, 89% had improvements in their endometriosis, 8% a deterioration and 3% no change. Patients reported improvement in the following: dysmenorrhoea 93%, dyspareunia 62% and pelvic pain 70%. However, all women complained of at least one of the following symptoms: hot flushes 86%, sleep disturbance 62%, sweating 61%, headache 41%, nausea 32% and depression 20%. Fifty-five percent of patients reported additional side effects such as vaginal dryness, fatigue and lower abdominal pain. After the third injection, amenorrhoea persisted in 94% of the women. Four weeks after the first leuprorelin acetate injection median concentrations of oestradiol fell from 45 pg/ml to 11 pg/ml, follicle-stimulating hormone from 7 U/L to 3 U/L and luteinising hormone from 5 U/L to 1 U/L and remained almost unchanged over the observation period. During the 6 months' treatment, laboratory parameters showed no significant deviations from normal; only total cholesterol, high-density lipoprotein cholesterol and alkaline phosphatase increased. Treatment results were judged as good and satisfactory in 82% and 11% of cases, respectively. On the basis of this study, it can be concluded that leuprorelin acetate treatment is safe, well tolerated and effective in the medical management of endometriosis and endometriosis-related complaints.

Experimental treatment of human Hodgkin's disease with ricin A-chain immunotoxins.

In the present paper we describe the evaluation of ricin A-chain immunotoxins for clinical application in Hodgkin's disease. The immunotoxins were constructed by chemically linking deglycosylated ricin-A to monoclonal antibodies (MoAb) recognising lymphocyte activation markers CD25, CD30, or IRac, which are expressed by Hodgkin's and Reed-Sternberg (H-RS) cells. The cytotoxic effects of the immunotoxins were investigated in vitro against L540Cy Hodgkin cells and in vivo against Hodgkin's tumors in nude mice and disseminated Hodgkin's tumors in SCID mice. MoAbs were evaluated for crossreactivity with normal human tissues and staining of sections from Hodgkin's disease tissue. Of 32 MoAbs, eight showed little crossreactivity with vital human organs and produced highly active immunotoxins. The most effective immunotoxin, RFT5 gamma l.dgA (CD25), inhibits the growth of H-RS cells at concentrations of 7 x 10(-12) M. RFT5 gamma l.dgA destroys about 60% of solid Hodgkin's tumors of 0.5 cm diameter in nude mice and induces complete remissions in 95% of SCID mice with disseminated Hodgkin's tumors when administered one day after tumor challenge. This immunotoxin binds to all H-RS cells in more than 90% of patients with Hodgkin's disease. Patients with refractory Hodgkin's disease are currently being treated in a phase-I/II clinical trial.

Clinical trials with an anti-CD25 ricin A-chain experimental and immunotoxin (RFT5-SMPT-dgA) in Hodgkin's lymphoma.

Immunotoxins (ITs) consisting of a cell-binding component and a potent toxin were developed as a new class of biological anti-tumor agents to improve adjuvant therapy. Hodgkin's lymphoma (HL) has been demonstrated to be an excellent target for ITs because high concentrations of lymphocyte activation markers such as CD25 and CD30 are expressed on Hodgkin and Reed-Sternberg (H-RS). Several ITs against these antigens have shown potent antitumor effects against H-RS cells in vitro and in different HL animal models. On the basis of its superiority in preclinical models, the anti-CD25 IT RFT5-SMPT-dgA was subsequently evaluated in a phase I study in patients with refractory Hodgkin's lymphoma. The IT was constructed by linking the monoclonal antibody (Moab) RFT5 via a sterically hindered disulfide linker (SMPT) to deglycosylated ricin A-chain (dgA). All 15 patients enrolled in this trial were heavily pretreated with a mean of five different prior therapies. The IT was administered intravenously over four hours on days 1-3-5-7 for total doses per cycle of 5, 10, 15, or 20 mg/m2. Side effects were reversible and related to the vascular leak syndrome (VLS), i.e. decrease in serum albumin, edema, weight gain, hypotension, tachycardia, myalgia, and weakness. In all three patients receiving 20 mg/m2 NCI toxicity grade III was observed. Thus, 15 mg/m2 is the maximal tolerated dose (MTD) of RFT5-SMPT-dgA. 50% of the patients developed human anti-ricin A-chain antibodies (HARA) and/or human anti-mouse antibodies (HAMA). Clinical results included two partial remissions (PR), one minor response (MR), three stable disease (SD) and nine progressive disease (PD). In an extension of the phase I trial, five additional patients have been treated at the MTD.

Effects of tibolone and continuous combined hormone replacement therapy on parameters in the clotting cascade: a multicenter, double-blind, randomized study.

OBJECTIVE: To determine the effects of tibolone and continuous combined HRT (ccHRT) on parameters in the clotting cascade. DESIGN: Randomized, double-blind study. SETTING: Hemostasis unit of a university hospital clinic in Germany. PATIENT(S): Sixty healthy postmenopausal women. INTERVENTION(S): Twenty-nine subjects were treated with tibolone (2.5 mg/d) and 31 with oral ccHRT containing estradiol (2 mg/d) + estriol (1 mg/d) + norethindrone acetate (1 mg/d). MAIN OUTCOME MEASURE(S): Effects on parameters in the clotting cascade at baseline and after 12 and 24 weeks of treatment. RESULT(S): Tibolone increased fibrinolysis parameters without significantly altering coagulation parameters. Treatment with ccHRT resulted in a stimulating effect on parameters of both fibrinolysis and coagulation. Tibolone showed a stronger reduction of factor VII activity; less reduction of AT-III, protein C activity, and protein S activity; stronger increase of the activated partial thromboplastin time, plasminogen and plasminogen-antiplasminogen complexes; and less increase of D-Dimer than ccHRT. Both preparations similarly reduced climacteric complaints, whereas tibolone showed less breast complaints than ccHRT. CONCLUSION(S): This study confirms that tibolone, and to a lesser extent also ccHRT, changes hemostasis parameters toward a more fibrinolytic profile, which may diminish the risk of venous thrombosis.

Effects of androgens on haemostasis.

Androgen deficiency is associated with an increased incidence of cardiovascular disease. There is evidence that thromboembolic disease as well as myocardial ifarction in hypogonadic males are mediated by low baseline fibrinolytic activity. Hypogonadism in males is associated with an enhancement of fibrinolytic inhibition via increased synthesis of the plasminogen activator inhibitor PAI 1. On the other hand, stanozolol and danazol reduce PAI 1 and are associated with increased fibrinolytic activity. However, in male abusers of anabolic steroids the net effect on the haemostatic system may change from anti- to prothrombotic; there appears to be an individual threshold dose above which thrombogenic effects on platelets and vasomotion may overcome the profibrinolytic effects on PAI 1. There are numerous reports on weight-lifters dying of atherothrombotic ischemic heart disease while abusing anabolic steroids. Androgens are known to have profound effects on carbohydrate and lipid metabolism. In fact, much of the individual inconsistency of the effects of androgens on fibrinolytic and haemostatic activity appears to be based on the close interrelationship of these metabolic systems. Androgens may have unfavourable effects on the HDL/LDL cholesterol ratio, on triglyceride levels and on the insulin/insulin-like growth factor 1 (IGF 1) system. Hypertriglyceridemia as well as insulin resistance are both associated with low fibrinolytic activity and increased PAI 1 levels. On the other hand, lipoprotein(a), a recently acknowledged independent risk factor of CVD was shown to respond favourable to androgen treatment, in men as well as in women. In women, agonistic as well as antagonistic effects of estrogens and progestins need to be taken into account. In fact, estradiol may modulate testosterone effects on haemostasis. Androgen medication in premenopausal women, such as danazol, was found to reduce PAI 1 suggesting an improvement of the fibrinolytic activity. Also, in hormone replacement therapy (HRT) androgenic progestins or complex compounds with androgenic effects are associated with a marked reduction of PAI 1 and an improvement of fibrinolytic activity. Further improvement of fibrinolytic activity may be associated with the marked decrease of lipoprotein (a) (Lp(a)) in women on androgenic HRT. However, little is known on the interrelationship of estrogens, 19-nortestosterone or progesterone derivatives and testosterone. an interrelationship that may have substantial impact on the metabolic and particularly haemostatic net effects of a preparation. In summary, information on the effects of androgens on haemostasis is limited and may be particularly incomplete due to the fact that interaction with other sex steroids appears to be an important confounder. In any case, there are numerous effects of synthetic androgens on the synthesis and release of haemostatic factors, namely an increase of the inhibitors of coagulation and a decrease of the inhibitor of the fibrinolytic system. However, the use of androgens in patients with congenital deficiencies of these coagulation factors or previous events of cardiovascular disease has yielded disappointing results. On the other hand, particularly the reduction of fibrinolytic inhibition (PAI 1) and Lp(a) were considered favourable effects of androgens with regard to the risk of cardiovascular disease. Differences between preparations with pronounced androgenic versus antiandrogenic effects and the effect of combined preparations need to be studied in much more detail. The profibrinolytic effects of androgens may be of particular interest with regard to favourable effects of HRT on cardiovascular disease.

Hormone replacement therapy and hemostasis: principles of a complex interaction.

Postmenopausal women on hormone replacement therapy (HRT) have been shown to be at reduced risk of arterial thrombotic disease. The risk of venous thrombosis appears not to be increased in HRT users in the absence of specific risk factors. However, while these data refer predominantly to women using conjugated equine estrogens, it is less clear whether the favourable impact on cardiovascular diseases may also be achieved by other preparations. Dose, as well as route of application and, particularly, the combination of steroids have been shown to affect both the clinical and the metabolic profile. With regard to cardiovascular diseases, differential effects on the hemostatic system are of particular interest. The principles of the interaction of steroids with the hemostatic system are reviewed. Also, the principal limitations of the assessment of the hemostatic system, as well as its interpretation, with regard to cardiovascular diseases are discussed. It is proposed to view the hemostatic system predominantly as a monitor of endothelial function rather than as a mediator of potential harmful effects on the cardiovascular system.

Blood coagulation and oral contraceptives. A critical review.

The use of oral contraceptives is associated with altered plasma concentrations of many components of the coagulation and fibrinolysis system, increased plasma levels of markers indicating in vivo coagulation and fibrinolysis, and a modified response to challenge tests both in vivo and in vitro. None of these effects seems to be specific for users of oral contraceptives and none was found uniformly in all users. The predictive value of each of these effects, or even of certain combinations of tests, for the prediction of venous thrombosis is low. There is no established way to assess the "thrombogenicity" of particular pills. The individual susceptibility, however, to develop venous thrombosis varies considerably. Recently, several congenital abnormalities of the hemostatic system have been found that are associated with an increased risk of venous thrombosis in general. The risk associated with the use of oral contraceptives appears to act synergistically with some of these thrombophilic conditions. Although the prevalence of these congenital predispositions varies among different populations, screening for these conditions is not feasible: negative results would not exclude the occurrence of about two-thirds of oral contraceptives-associated thromboses and positive results are likely to be disregarded because of their poor predictive value. Future research has to evaluate the role of a more targeted screening strategy aiming at women with risk factors such as a positive personal or family history of venous thromboembolism.

Hemostatic effects of third- and second-generation oral contraceptives: absence of a causal mechanism for a difference in risk of venous thromboembolism.

Some observational studies have found a difference in the risk of nonfatal venous thromboembolism (VTE) with low-dose, oral contraceptives (OCs) containing desogestrel (DSG) or gestodene (GSD) and those containing levonorgestrel (LNG). However, this does not agree with current pathophysiological concepts. This review compares all 17 comparative studies on the hemostatic effects of DSG/GSD- and LNG- or norgestimate (NGM)-containing OCs, and comments on two recent cross-sectional studies on the effects of third- and second-generation OCs on activated protein C (APC) sensitivity. In the comparative studies, the only difference in hemostatic parameters between DSG/GSD- and LNG- or NGM-containing OC users was a tendency towards higher factor VII (FVII) levels with DSG/GSD OCs. Differential effects on APC sensitivity were observed with the endogenous thrombin generation potential (ETP) assay, but not with the classical APC resistance test. FVII is not a risk marker for VTE, but is affected by dietary fat, estrogens and androgens and may interfere with the ETP assay. As no differences in established VTE risk markers were observed, there is no plausible reason for a differential risk of VTE with DSG/GSD- and LNG-containing OCs. In fact, the lack of differences with regard to established risk markers of VTE gives further support to the findings of the most recent epidemiological studies, which have not found any difference in the risk of VTE between third- and second-generation OCs.