Direct temporal characterization of sub-3-fs deep UV pulses generated by resonant dispersive wave emission.

We report on the complete temporal characterization of ultrashort pulses, generated by resonant dispersive wave emission in gas-filled hollow-capillary fibers, with energy in the microjoule range and continuously tunable from the deep-ultraviolet to the ultraviolet. Temporal characterization of such ultrabroad pulses, particularly challenging in this spectral region, was performed using an all-in-vacuum setup for self-diffraction frequency resolved optical gating (SD-FROG). Sub-3-fs pulses were measured, tunable from 250 nm to 350 nm, with a minimum pulse duration of 2.4 ± 0.1 fs.

Argentine tango in the care of Parkinson's disease: A systematic review and analysis of the intervention.

OBJECTIVE: To analyse the content of the interventions reported in studies investigating the applicability and efficacy of Argentine tango in participants with Idiopathic Parkinson Disease. METHODS: Independent reviewers searched databases (PubMed, CINAHL, EMBASE, PsycINFO, and PEDro) from their inception to November 2019. Eligible studies were randomised, controlled and uncontrolled clinical trials, and case reports. MAIN OUTCOME MEASURE: The Template for Intervention Description and Replication guidelines and checklist were used to assess quality and quantity of the content of Argentine tango interventions' description. RESULTS: We found 21 papers investigating the applicability and efficacy of Argentine tango in participants with Idiopathic Parkinson Disease. Completeness of the reporting of intervention was satisfying. The intervention is intended to affect a variety of aspects of functioning relevant to individuals with Idiopathic Parkinson Disease. Detailed information on the intervention's procedure and dosing is usually provided. The delivery of the Tango dance program was predominantly extensive; however, the intervention has been provided with various approaches and showed to be very adaptable. Attrition- and adherence- rates described are acceptable. The Adapted Tango dance program is the earliest and most researched modality of tango intervention in participants with Idiopathic Parkinson Disease. CONCLUSIONS: Argentine tango is appropriately described in the studies investigating the applicability and efficacy of the intervention in participants with Idiopathic Parkinson Disease. However, the reporting could be ameliorated.

Evaluation and review of body fluids saliva, sweat and tear compared to biochemical hydration assessment markers within blood and urine.

Evaluating and testing hydration status is increasingly requested by rehabilitation, sport, military and performance-related activities. Besides commonly used biochemical hydration assessment markers within blood and urine, which have their advantages and limitations in collection and evaluating hydration status, there are other potential markers present within saliva, sweat or tear. This literature review focuses on body fluids saliva, sweat and tear compared to blood and urine regarding practicality and hydration status influenced by fluid restriction and/or physical activity. The selected articles included healthy subjects, biochemical hydration assessment markers and a well-described (de)hydration procedure. The included studies (n=16) revealed that the setting and the method of collecting respectively accessing body fluids are particularly important aspects to choose the optimal hydration marker. To obtain a sample of saliva is one of the simplest ways to collect body fluids. During exercise and heat exposures, saliva composition might be an effective index but seems to be highly variable. The collection of sweat is a more extensive and time-consuming technique making it more difficult to evaluate dehydration and to make a statement about the hydration status at a particular time. The collection procedure of tear fluid is easy to access and causes very little discomfort to the subject. Tear osmolarity increases with dehydration in parallel to alterations in plasma osmolality and urine-specific gravity. But at the individual level, its sensitivity has to be further determined.

Straight motion of half-integer topological defects in thin Fe-N magnetic films with stripe domains.

In thin magnetic films with perpendicular magnetic anisotropy, a periodic "up-down" stripe-domain structure can be originated at remanence, on a mesoscopic scale (~100 nm) comparable with film thickness, by the competition between short-range exchange coupling and long-range dipolar interaction. However, translational order is perturbed because magnetic edge dislocations are spontaneously nucleated. Such topological defects play an important role in magnetic films since they promote the in-plane magnetization reversal of stripes and, in superconductor/ferromagnet hybrids, the creation of superconducting vortex clusters. Combining magnetic force microscopy experiments and micromagnetic simulations, we investigated the motion of two classes of magnetic edge dislocations, randomly distributed in an [Formula: see text]-implanted Fe film. They were found to move in opposite directions along straight trajectories parallel to the stripes axis, when driven by a moderate dc magnetic field. Using the approximate Thiele equation, analytical expressions for the forces acting on such magnetic defects and a microscopic explanation for the direction of their motion could be obtained. Straight trajectories are related to the presence of a periodic stripe domain pattern, which imposes the gyrotropic force to vanish even if a nonzero, half-integer topological charge is carried by the defects in some layers across the film thickness.

'Real-life' report on the management of chronic GvHD in the Gruppo Italiano Trapianto Midollo Osseo (GITMO).

Several guidelines have been published about management of chronic GvHD (cGvHD), but the clinical practice still remains demanding. The Gruppo Italiano Trapianto di Midollo Osseo (GITMO) has planned a prospective observational study on cGvHD, supported by a dedicated software, including the updated recommendations. In view of this study, two surveys have been conducted, focusing the management of cGvHD and ancillary therapy in cGvHD, to address the current 'real life' situation. The two surveys were sent to all 57 GITMO centers, performing allografting in Italy; the response rate was 57% and 66% of the interviewed centers, respectively. The first survey showed a great disparity especially regarding steroid-refractory cGvHD, although extracorporeal photo-apheresis resulted as the most indicated treatment in this setting. Another challenging issue was the strategy for tapering steroid: our survey showed a great variance, and this disagreement could be a real bias in evaluating outcomes in prospective studies. As for the second survey, the results suggest that the ancillary treatments are not standardized in many centers. All responding centers reported a strong need to standardize management of cGvHD and to participate in prospective trials. Before starting observational and/or interventional studies, a detailed knowledge of current practice should be encouraged.

Affectivity and sexuality in the elderly: often neglected aspects.

Sexuality and affectivity constitute a complex phenomenon involving many spheres: biological, psychological and social. To investigate these aspects, we distributed a dedicated questionnaire, followed by an interview, to 130 elderly residents in Milan and 100 in Monza. The answers indicated that the elderly communicate their emotions regarding the affective and sexual sphere, with different levels of desire for physical contact. The main variables were sex, age, marital status, co-morbidity and poly-pharmacotherapy, the perception of health status and of oneself, past experiences, cultural conditioning and social factors.

Low-molecular-weight heparin for the long-term treatment of symptomatic venous thromboembolism: meta-analysis of the randomized comparisons with oral anticoagulants.

BACKGROUND: The management of venous thromboembolism (VTE) requires an initial treatment with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH), followed by oral anticoagulants (OA) for at least 3 months. OA treatment however, requires laboratory monitoring of anticoagulation, carries a definite risk of bleeding, and may be contraindicated in some patients. As an alternative to vitamin K antagonists, subcutaneous LMWH has been proposed and evaluated in randomized clinical trials, but they are all small studies that lack the power to establish if these two treatment modalities are equivalent in efficacy or safety. OBJECTIVES: The objective of this review was to evaluate the efficacy (VTE recurrence) and safety (bleeds and deaths) of long-term treatment of VTE with LMWH compared with OA. A secondary endpoint was to evaluate the effect of LMWH on cancer mortality. METHODS: Computerized searches of MedLine and EmBase were performed. In addition, randomized clinical trials were located through personal communication with colleagues, and through the manual scanning of meeting proceedings and reference lists of relevant studies. When necessary, the authors of the selected papers were called to obtain additional information. Two reviewers (AI and FG) reviewed and extracted data independently using a standard form. The primary analysis was performed for efficacy and safety endpoints on an intention-to-treat basis for the study period of randomized treatment. A meta-regression analysis was used to investigate the relationship between daily dose and clinical outcome. RESULTS: Seven studies that fulfillled our predefined criteria were identified, for a total of 1379 patients. When all studies were combined, a statistically non-significant reduction in the risk of VTE (OR 0.66; 95% confidence interval [CI] 0.41, 1.07) and in the risk of major bleeding (OR 0.45; 95% CI 0.18, 1.11) in favor of LMWH treatment was found. No difference in total mortality (OR 1.19; 95% CI 0.78, 1.83) or in cancer-related mortality was observed between the LMWH and the OA treatment. CONCLUSIONS: The results of this meta-analysis indicate that a 3-month course of LMWH is as effective and safe as a corresponding period of OA treatment, and may thus be considered as a valuable alternative option for patients in whom OA treatment appears contraindicated or problematic.

Serum levels of tumour necrosis factor-alpha in patients with B-cell chronic lymphocytic leukaemia.

Serum levels of tumour necrosis factor-alpha (TNF-alpha) have been evaluated in the peripheral blood of 91 patients with B-cell chronic lymphocytic leukaemia (B-CLL), and have been correlated with the clinical stage (according to Rai's staging system) and relevant haematological and immunological data. Increased values were detected, compared to 36 normal age-matched controls (36 pg/ml +/- 5 versus 0.11 pg/ml +/- 0.08; P < 0.05). An increase of TNF-alpha serum levels was observed in all stages including stage 0, with a progressive increase in relation to the stage of the disease. A significant relationship between serum TNF-alpha levels and the number of circulating monocytes (P < 0.002) and an inverse correlation with the level of the haemoglobin (P < 0.001) was established, as defined by the Pearson's correlation test. In contrast, no correlation was observed between TNF-alpha serum levels and the other parameters taken into account, including the white blood cell and platelet counts, the absolute number of peripheral blood (PB) lymphocytes, CD5+ B lymphocytes, CD57+ lymphocytes, serum levels of lactic dehydrogenase, total serum immunoglobulins and the serum levels of IgG, IgA and IgM. These data suggest that, in addition to the B-CLL neoplastic cells, the PB monocytes may be involved in the release of TNF-alpha.

Congenital antithrombin III deficiency. Incidence and clinical features.

Antithrombin III (ATIII) deficiency is inherited as an autosomal dominant trait. Three types of ATIII deficiency are recognized clinically. The prevalence of ATIII deficiency is uncertain; it has been estimated to occur in between one in 2,000 and one in 20,000 subjects. ATIII deficiency is found in between 4 and 6 percent of young patients with venous thrombosis, similar to but slightly lower than the prevalence of protein C and protein S deficiency in young subjects with thrombosis. The chances of finding a deficiency is increased if there is a history of familial or recurrent venous thrombosis. Cross-sectional reports in the literature are that between 30 and 80 percent of carriers have thrombosis. Thrombosis is uncommon in the first decade, but the risk rises sharply between the ages of 15 and 30. The major clinical manifestations of ATIII deficiency are young age at onset, idiopathic thrombosis, family history, and recurrent venous thromboembolism. Pregnancy and surgery are predisposing factors. Approaches to prophylaxis and treatment are discussed.

A comparative study on the quality of oral anticoagulant therapy (warfarin versus acenocoumarol).

In our Center for the Surveillance of Anticoagulant Treatment, most of the 1700 patients followed-up are traditionally treated with acenocoumarol, while warfarin is administered nowadays to an increasing proportion of patients. To assess if the difference in the pharmacokinetics of these two drugs may determine a different laboratory quality of treatment, a retrospective study was performed on the computerized files of all 142 patients on treatment with warfarin for more than 100 days and on a control group of 142 patients treated with acenocoumarol, matched for age, sex, disease state and duration of oral anticoagulant therapy (OAT). The study considered 7071 assays for a total of 432 patient-years of treatment. The overall quality of treatment was significantly better in patients treated with warfarin (72% of controls within the therapeutic range versus 67% on acenocoumarol, p < 0.001). Also the individual quality of therapy, which was assessed as the percentage of patients with 75% or more assays in range, was in favour of warfarin (50.7% vs 34.5%, p < 0.05). Warfarin therapy was more stable and fewer assays were required for treatment monitoring. Confounding factors possibly influencing the treatment stability, such as interfering drugs, diagnostic or therapeutical procedures requiring withdrawal of anticoagulation, were evaluated and no significant difference between the two groups was found. The difference in the laboratory quality of OAT was marked in patients treated for prevention of arterial thromboembolism, while it was negligible in patients with venous thromboembolic disease, whose mean duration of OAT was considerably shorter. Since there is no evidence that acenocoumarol is more efficacious or safer than warfarin, the latter seems to be preferable for patients who are candidate to very prolonged OAT.

A pilot study of pro-urokinase in the treatment of deep vein thrombosis.

Safety and efficacy of the thrombolytic agent pro-urokinase (pro-UK) in the treatment of deep vein thrombosis of the lower limbs (DVT) have been investigated in an open, uncontrolled, pilot study. Fifteen patients were infused with 800.000 IU (5 mg)/h of pro-UK over 24 h (120 mg), together with unfractionated heparin adjusted to maintain the activated partial thromboplastin time between 1.5 and 2.5 times the basal value. Efficacy was assessed comparing venographic changes in the 11 evaluable limbs before and after pro-UK infusion. The Marder score decreased from a median pre-thrombolysis value of 28 (range 4-40) to 16 (3-38) (p < 0.05). One major hemorrhagic event (retroperitoneal bleeding 4 days after the end of the pro-UK infusion) occurred. Fibrinogen, alpha 2-antiplasmin and plasminogen significantly decreased from baseline values after 12 and 24 h, fibrin(ogen) degradation products significantly increased. Changes in hemostasis parameters were unrelated to thrombolytic efficacy. The results of this pilot study indicate that pro-UK is thrombolytic in DVT and that it can be administered simultaneously with conventional heparin treatment.

In vitro and in vivo effects of adrenaline and phentolamine on platelet function.

In vitro and in vivo effects of adrenaline (ADR) on platelet aggregation, on platelet factor 3 (PF3) availability and on platelet factor 4 (PF4) release were studied in man. Inhibitory action of an alpha-blocker, phentolamine (PHEN) was investigated in the same conditions. The threshold concentration (TC) of ADR inducing the typical two-phase response in aggregation tests when added to platelet-rich plasma (PRP) varied in different pools of plasma, but always induced an evident PF4 release and increased PF3 availability. A further increase in both parameters was obtained with higher concentrations but without any significant dose/response correlation. Adding PHEN alone to PRP did not induce platelet aggregation or modify PF4 release induced by stirring, but it reduced PF3 availability. On the other hand, PHEN prevented the effects of ADR in different platelet tests, at appropriate concentrations. Intravenous infusion of ADR lowered the TC, and increased PF3 availability and PF4 release. In vivo administration of PHEN, in contrast, increased TC and reduced PF3 availability, while PF4 remained unchanged.

Subcutaneous vs intravenous heparin in the treatment of deep venous thrombosis--a randomized clinical trial.

271 patients with acute symptomatic deep venous thrombosis of lower limbs, confirmed by strain-gauge plethysmography and/or venography, were randomly assigned to receive intermittent subcutaneous heparin calcium or heparin sodium by continuous intravenous infusion for 6-10 days. Heparin dosage was adjusted to maintain activated partial thromboplastin time values (Thrombofax reagent) at 1.3-1.9 times the basal ones. Strain-gauge plethysmography was repeated at the end of heparin treatment, and evaluation of therapy was performed by comparing the indexes of venous hemodynamics and by assessing the incidence of pulmonary embolism and of bleeding complications. In the intravenous group, Maximal Venous Outflow (MVO) increased from 20.8 +/- 12.8 to 28.4 +/- 17.5 ml/min per 100 ml of tissue and Venous Capacitance (VC) from 1.39 +/- 0.92 to 1.94 +/- 1.0 ml/100 ml of tissue (mean +/- SD). In the subcutaneous group, MVO increased from 21.0 +/- 12.7 to 27.5 +/- 18.1 and VC from 1.60 +/- 0.86 to 2.06 +/- 1.0. The median improvement of MVO and VC were 22% and 36% respectively in the IV group and 20% and 24% in the SC group. Clinical pulmonary embolism occurred in 2 patients in the intravenous group (1 fatal) and in 4 in the subcutaneous group (1 fatal). 9 major bleeding complications occurred in the intravenous group (1 fatal) and 5 in the subcutaneous group (1 fatal). The differences were not significant at the statistical analysis. The results suggest that subcutaneous intermittent heparin has a comparable efficacy to continuous intravenous heparin in the treatment of deep venous thrombosis. To the same conclusion points an overview of the seven randomized trials which compared these treatment modalities.

Low molecular weight heparin versus warfarin in the prevention of recurrences after deep vein thrombosis.

To evaluate the role of low-molecular weight heparin (LMWH) as an alternative to oral anticoagulants in the prevention of recurrent venous thromboembolism, we compared in a randomized trial conventional warfarin treatment with a three-month course of enoxaparin 4000 anti-Xa units once a day subcutaneously. 187 patients with symptomatic deep-vein thrombosis (DVT), diagnosed by strain-gauge plethysmography plus D-dimer latex assay and confirmed by venography in most cases, were treated with full-dose subcutaneous heparin for ten days and then randomized to secondary prophylaxis. During the 3-month treatment period, 6 of the 93 patients who received LMWH (6%) and 4 of the 94 patients on warfarin (4%) had symptomatic recurrence of venous thromboembolism confirmed by objective testing (p = 0.5; 95% confidence interval [CI] for the difference, -3% to 7%). Four patients in the LMWH group had bleeding complications as compared with 12 in the warfarin group (p = 0.04; 95% CI for the difference, 4% to 14%). In the 9-month follow-up period, during which 34 patients on warfarin prolonged treatment for other 3 months and 14 up to one year, 10 patients in the enoxaparin group and 4 patients in the warfarin group suffered a documented recurrence of venous thromboembolism. Of these 14 late recurrences, just one occurred in patients with postoperative DVT. After one year there were 16 recurrences (17%) in the LMWH group and 8 (9%) in the warfarin group (p = 0.07; 95% CI for the difference, 1% to 16%).(ABSTRACT TRUNCATED AT 250 WORDS)

Predictive value of preoperative in vitro and in vivo studies for correct individual heparinization in cardiac surgery.

Heparin administration for operations with extracorporeal circulation (ECC) usually is performed following prefixed, standardized protocols. These regimens secure an adequate level of anticoagulation, but they often involve prolonged periods of overheparinization associated with an undue risk of hemorrhage. The predictive value of preoperative studies in the anticoagulant effect of heparin was investigated in 10 patients. The study was performed both in vitro and in vivo using the Xa inhibitor assay as an index of the anticoagulation induced by heparin. Adding variable amounts of heparin in vitro to patient's plasma resulted in straight (at least up to 7 U. per milliliter) and parallel, but not coincident, dose/response curves, so confirming a different individual sensitivity to heparin. Disappearance curves of the anticoagulant effect in plasma following intravenous administration of a single standard dose of heparin in the same patients showed an even greater patient-to-patient variability, with "half-life" times ranging from 30 to 150 minutes. No relationship was found between the parameters (in vitro sensitivity to heparin and clearance rate from plasma in vivo). Moreover, neither of them could be correlated with the response to heparin, subsequently observed during ECC in the same patients. Preoperative investigations with the methods presently available are not adequate to choose individual heparin administration regimens for cardiac operations.

Combined use of Alpha 2b Interferon and Chlorambucil in the Management of Previously Treated B-Cell Chronic Lymphocytic Leukemia.

We hereby here the successful use of a combined therapeutic approach with alpha 2b Interferon (IFN) and Chlorambucil in the management of previously treated B-cell chronic lymphocytic leukemia (B-CLL). The two patients under study had been managed with repeated and frequent cycles of Chlorambucil. Rather than with more toxic multidrug regimens, the hematological picture was controlled with 3 MU of IFN every three-five days and 5 mg of Chlorambucil every two-five days. Using such an approach, which is feasible on an out-patients basis and devoid of significant side effects, a consistent control of the WBC count was achieved for 32 and 16 months, respectively.

Use of the MTT Chemosensitivity Assay in B-Cell Chronic Lymphocytic Leukemia.

The possibility of evaluating the susceptibility of B-cell chronic lymphocytic leukemia (B-CLL) cells to chemotherapeutic agents pre-clinically, was assessed using the MTT colorimetric assay. The results so far obtained suggest that this rapid 3-4 days' test is accurate and reliable and may allow the physician to recognize individual B-CLL cases in which the neoplastic clone is resistant to Chlorambucil. Furthermore, the high efficacy of Fludarabine clearly emerges from these in vitro analyses. The possibility of employing Chlorambucil in combination with alpha Interferon is suggested and the relevance of using this simple test for better drug selection in B-CLL patients is discussed.

The treatment of elderly patients with aggressive non-Hodgkin's lymphomas: feasibility and efficacy of an intensive multidrug regimen.

The results of a prospective trial of an 8 week treatment for elderly patients with advanced intermediate-high grade NHL are reported. Our aim was to reduce general toxicity without losing an antilymphoma effect. For this reason the use of growth factor was studied. We also analysed the behavior of different histological groups (E + F vs G + H). From November 1991 to November 1993 100 patients older than 65 years with combination intermediate-high grade advanced stage NHL were treated with the P-VEBEC regimen, an original including epirubicin 50 mg/sqm, cyclophosphamide 300 mg/sqm and etoposide 100 mg/sqm on weeks 1, 3, 5, 7; vinblastine 5 mg/sqm and bleomycin 5 mg/sqm on weeks 2, 4, 6, 8; prednisone 50 mg/sqm/day per os in the first two weeks and thereafter every other day .46 pts received rG-CSF 5 micrograms/Kg/day throughout the treatment starting on day 2 of every week for 4 consecutive days. Twenty eight pts had B symptoms, 41 had bulky disease, 37 LDH levels above normal, 50 stage IV patients and 30 had bone marrow involvement. Sixty two percent achieved a complete remission (CR). Adverse prognostic factors for CR were E and F histology, stage IV disease, bone marrow infiltration, serum LDH levels above normal, international Prognostic Index (I.I.) intermediate-high and high risk categories and relative dose intensity (RDI) less than 0.80. Severe toxicity was rarely recorded and only one toxic death was observed. With a median follow-up of 33 months OS, DFS and EFS were 44%, 60% and 30% respectively. EFS was influenced by stage, BM involvement, level of LDH and I.I. intermediate-high and high risks. The 52 patients with DLCL (diffuse large cell lymphomas--G + H according to WF) did better with a higher CR, OS, DFS and EFS rates, than the other WF subtypes. In conclusion P-VEBEC is a feasible combination to use in elderly patients, mainly in DLCL. The use of rG-CSF improves the RDI. A RDI > 0.80 could play a role in improving the outcome, especially in patients with adverse prognostic factors. For other subgroups another schedule is probably justified.

Accuracy of strain-gauge plethysmography as a diagnostic test in clinically suspected deep venous thrombosis.

Strain-gauge plethysmography (SGP) is currently employed in the diagnosis of deep venous thrombosis (DVT), but its accuracy has not been adequately tested. In this study we evaluated SGP against venography in 209 consecutive patients referred to us because of clinically suspected DVT of lower limbs. Venography was performed bilaterally if symptoms or signs suggesting DVT were present in both limbs. It was always performed after SGP and independently assessed. A total of 269 limbs could be evaluated with both SGP and venography, which disclosed DVT in 128 limbs of 110 patients. There were 109 proximal and 19 distal DVT. Out of the 128 limbs with DVT, SGP was positive in 114 (sensitivity = 89%) using Maximal Venous Outflow (MVO) as the diagnostic parameter, and positive in 116 (sensitivity = 91%) using an index obtained multiplying MVO for Venous Capacitance (VC). Out of the 141 venographically negative limbs, there were 6 false positive results using MVO and 9 using MVO X VC (specificity = 96% and 94% respectively). SGP sensitivity in acute proximal venous thrombosis was 97%, while it was about 60% in distal DVT. Most false positive results occurred in patients with edema of cardiac origin. SGP appears to be a useful diagnostic test in suspected DVT of lower limbs, particularly when both MVO and the index MVO X VC are used.

Future prospects of prophylaxis for deep vein thrombosis.

The last decade has witnessed substantial progress in the prevention and treatment of venous thromboembolism. However, the risk of deep vein thrombosis remains high in trauma patients and those undergoing orthopaedic surgery despite use of the best available prophylaxis. Existing antithrombotics also carry a significant risk of bleeding and other adverse effects, including heparin-induced thrombocytopenia (HIT). More effective and safer anticoagulants are therefore needed. Current approaches for improving the benefit:risk ratio of antithrombotic therapy include the development of indirect thrombin inhibitors with a high anti-Xa:anti-IIa activity ratio, and the use of direct thrombin inhibitors. Novel indirect thrombin inhibitors under investigation include pentasaccharide and the heparinoid danaparoid. These agents may offer reduced bleeding risk compared with conventional therapies, but there is no evidence of greater antithrombotic efficacy. However, due to low cross-reactivity with anti-heparin-platelet factor 4 antibodies, danaparoid and pentasaccharide may prove valuable in the management of HIT. Theoretically, the antithrombotic effect of direct thrombin inhibitors may be greater than that of indirect inhibitors because direct inhibitors are not dependent on endogenous cofactors and are able to inhibit both free and clot-bound thrombin. Direct inhibitors of the active site of thrombin and recombinant variants of hirudin, originally derived from the medicinal leech, are currently under investigation. Early data on lepirudin and desirudin suggest that recombinant hirudins may have clinical applications in thromboprophylaxis for high-risk patients, acute cardiology indications and HIT.