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Inherited thrombophilia (e.g., venous thromboembolism, VTE) is due to rare loss-of-function mutations in anticoagulant factors genes (i.e., SERPINC1, PROC, PROS1), common gain-of-function mutations in procoagulant factors genes (i.e., F5, F2), and acquired risk conditions. Genome Wide Association Studies (GWAS) recently recognized several genes associated with VTE though gene defects may unpredictably remain asymptomatic, so calculating the individual genetic predisposition is a challenging task. We investigated a large family with severe, recurrent, early-onset VTE in which two sisters experienced VTE during pregnancies characterized by a perinatal in-utero thrombosis in the newborn and a life-saving pregnancy-interruption because of massive VTE, respectively. A nonsense mutation (CGA > TGA) generating a premature stop-codon (c.1171C>T; p.R391*) in the exon 6 of SERPINC1 gene (1q25.1) causing Antithrombin (AT) deficiency and the common missense mutation (c.1691G>A; p.R506Q) in the exon 10 of F5 gene (1q24.2) (i.e., FV Leiden; rs6025) were coinherited in all the symptomatic members investigated suspecting a cis-segregation further confirmed by STR-linkage-analyses [i.e., SERPINC1 IVS5 (ATT)5–18, F5 IVS2 (AT)6–33 and F5 IVS11 (GT)12–16] and SERPINC1 intragenic variants (i.e., rs5878 and rs677). A multilocus investigation of blood-coagulation balance genes detected the coexistence of FV Leiden (rs6025) in trans with FV HR2-haplotype (p.H1299R; rs1800595) in the aborted fetus, and F11 rs2289252, F12 rs1801020, F13A1 rs5985, and KNG1 rs710446 in the newborn and other members. Common selected gene variants may strongly synergize with less common mutations tuning potential life-threatening conditions when combined with rare severest mutations. Merging classic and newly GWAS-identified gene markers in at risk families is mandatory for VTE risk estimation in the clinical practice, avoiding partial risk score evaluation in unrecognized at risk patients.

SummaryAfter acute myocardial infarction (MI) the damaged heart has to be repaired. Factor XIII (FXIII) is considered a key molecule in promoting heart healing. FXIII deficiency was associated to cardiac rupture and anomalous remodelling in MI. During MI, FXIII contributes firstly to the intracoronary thrombus formation and shortly after to heal the myocardial lesion. To quantify the real contribution of FXIII in this process, and to explore its possible prognostic role, we monitored the FXIII-A subunit levels in 350 acute MI patients during the first six days (d0-d5) plus a control at 30–60 days (d30). A one-year follow-up was performed for all the patients. A transient drop in the FXIII-A mean level was noted in the whole cohort of patients (FXIII-Ad0 99.48 ± 30.5 vs FXIII-Ad5 76.51 ± 27.02; p< 0.0001). Interestingly, those who developed post-MI heart failure showed the highest drop (FXIII-Ad5 52.1 ± 25.2) and they already presented with low levels at recruitment. Similarly, those who died showed the same FXIII-A dynamic (FXIII-Ad5 54.0 ± 22.5). Conversely, patients who remained free of major adverse cardiac events, had lower consuming (FXIII-Ad0 103.6 ± 29.1 vs FXIII-Ad5 84.4 ± 24.5; p< 0.0001). Interestingly, the FXIII-A drop was independent from the amount of injury assessed by TnT and CKMB levels. The survival analysis ascribed an increased probability of early death or heart failure inversely related to FXIII-A quartiles (FXIII-A25th< 59.5 %; hazard ratio 4.25; 2.2–5.1; p< 0.0001). Different FXIII-A dynamics and levels could be utilised as early prognostic indicators during acute MI, revealing the individual potential to heal and suggesting tailored treatments to avoid heart failure or its extreme consequence.Note: This paper was presented in part at the 14th Congress of the International Society on Thrombosis and Haemostasis, Amsterdam, Netherlands, June 29 – July 24, 2013.

The cost of a hermetic reciprocating compressor is quite dependent on the electric motor employed to drive it. Usually, the higher the motor efficiency, the higher the costs. Therefore, some compressors are designed to operate with low-efficiency electric motors. The main difficulty in such a case is to ensure that the motor operates at a temperature below the upper threshold. This paper presents a simulation model for optimization of fins on the shell of a hermetic reciprocating compressor which operates with a low-efficiency motor. The objective of the simulation is to obtain a set of fins with minimum volume that allows the compressor to operate under a critical operating condition without overheating the electric motor. The simulation model is implemented by coupling a lumped-parameter thermal simulation model of the reciprocating compressor with an optimization algorithm. The results of the thermal simulation are validated with experimental data. Different fin profiles are considered in the analysis. It is concluded that the optimum heat sink solution is conditioned to the minimum fin thickness or to the minimum fin diameter allowed, which are dependent on other compressor design constraints.

A Registry of inherited bleeding disorders was set up in the Region of Emilia-Romagna (RER) to collect information about these diseases and to improve the quality of care. From January 2003, the eight Haemophilia Centres (HC) in the RER began to use computerized clinical records; every 6 months, they send data to Parma Hospital to be processed and published in a website (http://www.registroemofiliarer.it). Great efforts are made to ensure high quality of data. Results of general interest are included in a free 'public area' and more sensitive data in a 'reserved area' (open only to HC and to health authorities). A total of 610 individuals are included: 249 haemophilia A (HA), 63 haemophilia B (HB), 173 von Willebrand's disease, 69 rare bleeding disorders, seven platelet disorders and 49 haemophilia carriers; 131 were genotyped, 188 were tested for inhibitors (16 affected). The most frequent bleeding was haemarthrosis. The joint score (evaluated in 104 haemophiliacs) was higher in severe HA. There were 22 HIV-positive and 182 hepatitis C virus-positive patients (21% have chronic hepatitis, two hepatocellular carcinoma). In 2005, two patients received primary prophylaxis, 47 secondary prophylaxis, four children were on immune-tolerance induction. From 2003 to 2005 the use of recombinant products was greatly increased and the majority of patients received them. The mean clotting factor consumption for prophylaxis was higher than on-demand treatment. The main features of registry are to collect high quality and comprehensive data of all patients followed by HC, to improve quality of care and it's availability on the web.

The number of sequences generated by genome projects has increased exponentially, but gene characterization has not followed at the same rate. Sequencing and analysis of full-length cDNAs is an important step in gene characterization that has been used nowadays by several research groups. In this work, we have selected Schistosoma mansoni clones for full-length sequencing, using an algorithm that investigates the presence of the initial methionine in the parasite sequence based on the positions of alignment start between two sequences. BLAST searches to produce such alignments have been performed using parasite expressed sequence tags produced by Minas Gerais Genome Network against sequences from the database Eukaryotic Cluster of Orthologous Groups (KOG). This procedure has allowed the selection of clones representing 398 proteins which have not been deposited as S. mansoni complete CDS in any public database. Dedicated sequencing of 96 of such clones with reads from both 5' and 3' ends has been performed. These reads have been assembled using PHRAP, resulting in the production of 33 full-length sequences that represent novel S. mansoni proteins. These results shall contribute to construct a more complete view of the biology of this important parasite.

To investigate simultaneously a defect affecting the protein C/protein S (PC/PS) anticoagulant pathway is possible thanks to a methodological approach (ProC(R) Global; Dade Behring) based on the activation of endogenous plasma PC by a snake venom extract. Factor V (FV) Leiden, the most frequent cause of hereditary thrombosis, is well detected by the test with sensitivity of 100% irrespective of the presence/absence of thrombosis in the subjects investigated. The test is also suited to detect PC or PS defect, but in this case the in vitro impairment of the PC/PS pathway is less pronounced particularly for PS defects (sensitivity for PC and PS defect, 85-100 and 30-90%, respectively). In this study, we hypothesized that the lower sensitivity described for PS defect, compared with those of PC and FV Leiden defects, could also be related to the clinical condition of the subject investigated (symptomatic/asymptomatic) rather than solely to the PS plasma activity/level. Therefore, we analyzed 126 subjects with single congenital defects in the PC/PS pathway: 46 subjects with PS deficiency (26 thrombotic cases and 20 asymptomatic relatives), 40 subjects with PC deficiency (25 thrombotic cases and 15 asymptomatic relatives), and 40 heterozygous FV Leiden subjects (25 thrombotic cases and 15 asymptomatic relatives). By a cut-off of normalized Agkistrodon contortix snake venom ratio of 0.84, the sensitivity in the whole group of cases (sensitivity a) was 76.1, 95.0 and 100%, respectively, for PS, PC and FV Leiden defects. The test failed to detect 11 (23.9%) among the 46 PS-deficient subjects, and all these cases except two belonged to the asymptomatic subgroup (9/20; 45%). Excluding the 20 asymptomatic relatives, the new sensitivity (sensitivity b) for the PS defect was 92.3%. The comparison of the sensitivity in the symptomatic PS cases and in the asymptomatic ones was significantly different (P = 0.010). Among the 40 PC-deficient subjects, only two (5.0%) were not detected by the test and they belonged indifferently to the two subgroups. Finally, none of the 40 FV Leiden heterozygotes were misdiagnosed by the test. These results suggest that in symptomatic PS-deficient cases the test could reflect a post-thrombotic effect and/or reveal potential unidentified prothrombotic influences assessing a prothrombotic risk condition.

In order to define the thrombophilic conditions related to activated protein C resistance (APC-R) and protein S (PS) deficiency and to detect the possible combination of these defects, we studied nine unrelated patients selected because of low anticoagulant response to APC and reduced PS activity with at least one first degree relative having the same coagulation feature. The mean APC ratio was 0.64 (normal values > 0.80) and range 0.35-0.80. Three of the patients were heterozygous and two were homozygous for the Leiden mutation (FVR506Q); in the remaining four there was no mutation. The mean PS activity was 41.6% and range 32-54 (normal 65-150%). Five of the patients had low PS activity despite normal total and free antigenic levels, and normal activity when measured at higher plasma dilution; these were carrying at least one gene for the Leiden mutation. In the remaining four patients the crossed-immunoelectrophoresis and the Western-blotting analysis showed a type I PS deficiency confirmed by the familial restriction fragment length polymorphism analysis. Thus, four families were diagnosed with the type I PS defect and five with congenital APC-R. No combined PS/FV Leiden or type II PS defect was found. The only defect found was in the anticoagulant PC pathway. We therefore designed a procedure to diagnose thrombophilic conditions related to this pathway. This study indicates that a specific methodological approach must be used to accurately characterize APC-R and PS deficiency and that care is necessary to avoid the possibility of misdiagnosis.

Objectives Warfarin oral anticoagulant therapy (OAT) requires regular and frequent drug adjustment monitored by INR. Interindividual variability, drug and diet interferences, and genetics (VKORC1 and CYP2C9) make the maintenance/reaching of stable INR a not so easy task. HPLC assessment of warfarin/enantiomers was suggested as a valid monitoring-tool along with INR, but definite results are still lacking. We evaluated possible correlations between INR, warfarin/3’-hydroxywarfarin, and drug weekly dosage aimed at searching novel alternatives to OAT monitoring. VKORC1/CYP2C9 pharmacogenetics investigation was performed to account for the known influence on warfarin homeostasis. Methods 133 OAT patients were recruited and assessed for warfarin/3’-hydroxywarfarin serum levels (HPLC), INR, and VKORC1 and CYP2C9 genotypes. A subgroup of 52 patients were monitored in detail (5 consecutive controls; c0-c4) till the target INR was reached. Correlation analyses were performed in both groups Results In the whole OAT group both warfarin and 3’-hydroxywarfarin correlate with INR at comparable degree (r2 = 0.0388 and 0.0362 respectively). Conversely, warfarin weekly dosage better correlates with warfarin than with 3’-hydroxywarfarin (r2 = 0.0975 and r2 = 0.0381 respectively), but considering together warfarin plus 3’-hydroxywarfarin the correlation strongly increased (r2 = 0.1114; p

Summary Von Willebrand disease (VWD) is an inherited bleeding disorder caused by the quantitative or qualitative deficiency of von Willebrand factor (VWF). Replacement therapy with plasma-derived VWF/factor VIII (FVIII) concentrates is required in patients unresponsive to desmopressin. To assess the efficacy, safety and ease of use of a new, volume-reduced (VR) formulation of VWF/FVIII concentrate Haemate® P in patients requiring treatment for bleeding or prophylaxis for recurrent bleeding or for invasive procedures. Pharmacoeconomic variables were also recorded. Data were analysed using descriptive statistics. This was a multicentre, prospective, observational study. Consecutively enrolled patients received Haemate® P VR according to their needs, and were followed for 24 months. Of the 121 patients enrolled, 25.6% had type 3 VWD and more than 40% had severe disease. All patients were followed for 2 years, for a total of 521 visits. On-demand treatment was given to 61.9% of patients, secondary long-term prophylaxis to 25.6% and prophylaxis for surgery, dental or invasive procedures to 45.5%. The response to treatment was rated as good to excellent in >93–99% of interventions. The new formulation was well tolerated by all patients with no report of drug-related adverse events. The switch to volume-reduced Haemate® P was easy to perform and infusion duration was decreased twofold compared with the previous formulation. Volume-reduced Haemate® P was at least as effective and well-tolerated as the previous formulation.

Proteomics correspond to the identification and quantitative analysis of proteins expressed in different conditions or life stages of a cell or organism. Methods used in proteomics analysis include mainly chromatography, two-dimensional electrophoresis and mass spectrometry. Data generated in proteomics analysis vary significantly, and to identify a protein it is often necessary to perform a series of experiments, comparing its results to those found in proteomics databases. Existing proteomics databases are usually related to only one type of experiment or represent processed results, not raw data. Therefore, proteomics researchers frequently have to resort to several data repositories in order to be able to perform the identification. In this paper, we propose an integrated proteomics and transcriptomics database that stores raw and processed data, which are indexed allowing them to be retrieved together or individually. The proposed database, dubbed BNDb for Biomolecules Nucleus Database, is implemented using an MySQL server and is being used to store data from the parasite Schistosoma mansoni, the scorpion Tittyus serrulatus and the spider Phoneutria nigriventer. The database construction uses a relational approach and data indexes. The data model proposed uses groups of tables for each data subtype, which store details regarding the experimental procedure as well as raw data, analysis results and associated publications. BNDb also stores transcriptomics data publicly available which are associated with identifications performed on new samples. By using BNDb, we expect not only to contribute to proteomics research but also to provide a useful service for the scientific community.

Two G-to-A mutations at positions 1691 of the factor V (FV) gene and 20210 of the prothrombin (FII) gene have been associated with an increased risk of venous thromboembolism. We report a thrombosis-prone family in which one subject – the propositus who exhibited combined heterozygous FV G1691A and FII G20210A mutations – showed spontaneous and early clinical onset (at 23 years), recurrences of deep-vein thrombosis and pulmonary embolism. His asymptomatic father carried the FII G20210A substitution and his mother, characterized by an isolated thrombotic episode on occasion of surgery (at 48 years), carried the FV G1691A substitution. In the maternal lineage, one of the propositus’ uncles had thrombosis on occasion of a bone fracture (at 65 years) despite the absence of known prothrombotic defects. A sister of the propositus carried the FII G20210A and the brother the FV G1691A mutation. They have been asymptomatic until now. The propositus’ two children, 20 and 16 years old, both carry the FV G1691A substitution and have been asymptomatic until now. The plasma levels of FII were higher in carriers of the FII G20210A allele if compared with noncarriers, and the activated protein C resistance phenotype, associated with the FV Leiden mutation, showed a complete correlation with the FV G1691A mutation. Despite the very limited number of thrombotic cases involved in this survey, which does not allow statistically sound conclusions, the data obtained from this family suggest that the synergy of inherited factors and transient risk conditions could play a key role in the occurrence of thrombotic accidents.

The role of a common polymorphism in the factor XIII A-subunit gene (FXIII Val34Leu) has been recently investigated as a protective genetic factor against arterial and venous thrombosis. In addition, the less frequent Leu34 allele has been described as a risk factor for intracerebral hemorrhage. We evaluated the prevalence of this polymorphism by PCR in three case-control studies of patients diagnosed as having primary intracerebral hemorrhage (PCH, n = 130), coronary heart diseases (CHD, n = 240; myocardial infarction/no myocardial infarction, 120/120), and cerebrovascular diseases (CVD, n = 240; cerebral infarction/transient ischaemic attack, 120/120). The matched control groups consisted of patients admitted to the hospital without history of vascular disease. In addition, 200 healthy subjects were investigated. The frequency of the mutated allele (Leu34) was higher in patients with PCH than in controls (33.8% vs. 23.1%, P = 0.009) and lower in CHD and CVD patients compared to controls (18.1% vs. 25.2%, P = 0.010 and 17.3% vs. 24.2%, P = 0.011, respectively). Moreover, among the patients with CHD, the Leu34 allele was underrepresented in cases with myocardial infarction than without (12.9% vs. 23.3%, P = 0.004) and than in controls (12.9% vs. 25.2%, P < 0.001). Similar findings were obtained in patients with CVD comparing the cases with cerebral infarction versus cases with transient ischaemic attack (12.5% vs. 22.1%, P = 0.008) and versus controls (12.5% vs. 24.2%, P < 0.001). Finally, considering altogether the groups of ischaemic patients (CHD and CVD, n = 480), it was noted a trend towards a higher mean age of the clinical onset in homozygotes for the Leu allele than in the wild types (P = 0.078). This study indicates that in our population possession of the FXIII Val34Leu mutation predisposes to the occurrence of primary intracerebral hemorrhage and protects against cerebral and myocardial infarction. A wider modulatory role in the progression and onset of atherothrombotic diseases could be ascribed to FXIII Val34Leu. Am. J. Hematol. 67:183–188, 2001. © 2001 Wiley-Liss, Inc.

Abstract —Several studies have indicated that mild to moderate hyperhomocystinemia is a common cause of arterial occlusive disease. Whether hyperhomocystinemia per se is an independent risk factor for vein thromboembolism (VTE) is still somewhat controversial. Both genetic and nutritional factors influence plasma homocysteine levels. Therefore, we evaluated plasma total homocysteine (tHcy), folate, and vitamin B 12 levels and established, by polymerase chain reaction, the presence of the C677T mutation (A223V) in the methylenetetrahydrofolate reductase ( MTHFR ) gene in 220 cases with VTE without well-established prothrombotic defects. As a control group, 220 healthy subjects from the same geographic area as the cases were investigated. Hyperhomocystinemia was defined as a plasma tHcy level above the 95th percentile in the controls (18.05 μmol/L). Hyperhomocystinemia was found in 16% of cases (odds ratio=3.59; P 12 (P P =0.015) of cases, respectively. The homozygous condition for the MTHFR mutation (VV) was present in 28.2% of cases and 17.7% of controls (odds ratio=1.82; P =0.013). Comparing only the idiopathic forms of VTE (n=80/220; 36.3%) with normal controls, individuals with hyperhomocystinemia, or individuals homozygous for MTHFR mutation increased the odds ratios to 4.03 ( P =0.005) and 2.11 ( P =0.018), respectively. No statistically significant difference was observed in the MTHFR genotype distribution of cases and controls with hyperhomocystinemia ( P =0.386); however, the normal MTHFR genotype (AA) appeared in control subjects only when tHcy levels were below the 80th percentile (10.57 μmol/L) of the distribution, whereas in case patients, it was present at the highest tHcy levels. A strong association between mutated homozygosity (VV), low folate levels, and hyperhomocystinemia was found in both groups. We conclude that in patients with VTE who do not have coexisting prothrombotic defects, hyperhomocystinemia increases the risk of developing idiopathic and venous thrombosis; the homozygous condition for the MTHFR mutation confers a moderate risk but, together with low folate levels, it is the main determinant of mild hyperhomocystinemia in normal and thromboembolic populations.

Hemostatic parameters of 495 beta-thalassemic patients (421 with thalassemia major and 74 with thalassemia intermedia) were analyzed, to assess their association with the described thrombophilic condition and to verify the role of additional risk factors (e.g. persistent postsplenectomy thrombocytosis, insulin dependent diabetes mellitus, estrogen-progestin treatment and atrial fibrillation). The prevalence of thromboembolic accidents was 5.2% and in four patients (15.3%) inherited or acquired predisposing defects were recognized. The incidence of thromboembolic events and the associated relative risk due to hemocoagulative abnormalities in these patients are discussed.

Acquired deficiency of clotting factor VIII (FVIII) is a rare bleeding diathesis seldom encountered in systemic lupus erythematosus (SLE). Reduction of FVIII activity by autoantibodies can cause potentially life-threatening situations. Herein, an SLE patient with a positive lupus anticoagulant (LAC) test who abruptly developed metrorrhagia 4 yr after diagnosis is reported. Coagulation tests revealed FVIII activity reduced to 3% and a prolonged aPTT. FVIII inhibitor(s) were found to be as high as 3.0 Bethesda Units. Plasmapheresis, immunoglobulins, prednisolone and FVIII plasma concentrates induced the cessation of metrorrhagia, but the clotting tests were barely improved. One month later, extensive ecchymosis appeared and worsened, despite re-administration of the previous therapy. Pulse cyclophosphamide followed by oral administration was then started with normalization of coagulation parameters and long-lasting disease remission.

We report a thrombotic family with combined type I antithrombin deficiency and factor V Leiden (factor V-R506Q) in which the proposita, affected by recurrent venous and arterial thrombosis, was also characterized by mild hyperhomocysteinemia (28 micromol/l; normal

We studied a patient affected by von Willebrand disease type 2A who experienced several mild bleeding episodes and was characterized by markedly reduced haemostatic parameters. In the exon 28 of von Willebrand factor (vWF) gene a T to C transition at nucleotide 8680, resulting in the missense mutation Leu817Pro, was found in the heterozygous form in the patient and in two affected relatives. As suggested by the presence in platelets of a complete spectrum of VWF multimers as well as by the increased vWF antigen levels and improved haemostasis after DDAVP treatment, the mutation is compatible with normal multi-merization, and could be responsible for a reduced stability or an impaired physiological secretion of vWF.

The lupus anticoagulant (LAC) and anticardiolipin antibody (ACA) syndromes require particular therapeutic approaches: thrombotic accidents are an indication for oral anticoagulant therapy (OAT), whereas severe thrombocytopenia may require the special treatments used for immunologic thrombocytopenic purpura (ITP). We describe the case of a 21-year-old male who presented with axillary vein thrombosis associated with LAC and ACA at high titers in December 1990. OAT was begun and, due to repeated episodes of thrombocytopenia, high-dose steroid therapy was later added with success. The daily steroid dose was reduced because of patent hypercortisolism, but the platelet count fell to 4 x 10(9)/L. A bone marrow biopsy was characteristic for ITP. Splenectomy was performed in June 1993, and the platelet count rapidly normalized. Platelet antibodies were always detectable before and after splenectomy. The patient is currently asymptomatic, with platelet counts above 300 x 10(9)/L at one and a half years after splenectomy. This case indicates that ACA-associated thrombocytopenia, like ITP and HIV-related thrombocytopenias, can be successfully treated with steroids and splenectomy, even though different pathogenetic mechanisms are responsible for the antibody-induced platelet consumption.

Oral anticoagulants are extensively used in everyday medical practice, especially for the prophylaxis of deep vein thrombosis and pulmonary thromboembolism. Bleeding is the major risk of such therapy. Although infrequent, however, non-haemorrhagic complications may also play a considerable role. The purpose of this paper is briefly to review the most important non-haemorrhagic adverse reactions and their clinical signs. Moreover, the pathogenetic hypotheses, the relationships with protein C and S levels, and the possibility of prevention and treatment are also discussed.

To identify the defect(s) responsible for the thrombotic condition affecting a 55-year-old male and his family, we have utilized a new methodological approach (ProC Global®, Istituto Behring, Milan, Italy) to screen the global anticoagulant activity of the protein C pathway, a defect that accounts for the majority of inherited thrombophilias. The test is based on the activation of endogenous protein C in plasma by Protac®, derived from Agkistrodon contortix snake venom (ACV test). Nineteen members of the family were investigated, 11 showed low responsiveness to ACV (normalized ACV ratios < 0.66; normal > 1. 12); in these individuals specific assays of protein C (PC) and protein S (PS) levels and normalized activated protein C ratios (n-APC-r) were performed. A second test evaluating response to APC, using the classic commercial APC test (n-APC-r 1), detected only 10 subjects with abnormal responses : the propositus and two members of the family with n-APC-r 1 values < 0.54, indicating the homozygous state for the R506Q factor V gene mutation, and seven with values ranging 0.69-0.83, consistent with the heterozygous condition (normal > 0.85). Although only ten subjects presented with low n-APC-r 1 values, DNA analysis, in agreement with the ACV test, detected 11 individual with factor V-R506Q substitution (two homozygotes and nine heterozygotes). Thus the classical APC test failed to identify the APC resistance phenotype in two heterozygous subjects whose values were clearly normal (1.05) in the first case and homozygous (0.53) in the second. The ACV test, however, and the modified APC test with test plasma 1/5 diluted in factor V-deficient plasma (n-APC-r 2) completely matched the DNA analysis. A phenotype/genotype correlation was observed in dilutions higher than 1/3 test plasma factor V-deficient plasma. The presence of unknown mechanisms that influence plasma response to exogenous preformed APC (normal at high factor V-deficient plasma dilutions) but not endogenous ACV activated PC was suspected. The suspected low levels of proteins C and S found in several R506Q members of the family were excluded by reassaying the anticoagulant activities at higher plasma dilution ; this supports the known influence of factor V Leiden on functional PC and PS clotting activity. We conclude that the ACV test is appropriate to evaluate the APC resistance condition, but for a firm diagnosis DNA analysis together with the modified APC test are strongly advised even in the presence of unquestionable APC-r values. Key Words: APC resistance-Factor V Leiden-APC test-ACV test-Diagnosis-Inherited thrombophilia.

Iron excretion following subcutaneous administration of deferrioxamine (DFO) was measured between two transfusions of packed red cells in 6 patients with beta-thalassaemia major on the high level Hb transfusion regime; and in a single 3-day period in 2 other patients, 1 with transfused beta-thalassaemia major and the other with haemolytic anaemia due to PK deficiency. The pattern of iron excretion did not change significantly during the period between the two transfusions and was found to be related to serum ferritin levels. The proportion of iron excreted in the stools was inversely related to the serum ferritin level. These observations on iron excretion are of practical importance in relation to DFO administration, especially when evaluated in thalassaemics with normal haemoglobin levels and low iron stores.