Fast Fourier transform IR characterization of epoxy GY systems crosslinked with aliphatic and cycloaliphatic EH polyamine adducts.

The use of fast FT-IR spectroscopy as a sensitive method to estimate a change of the crosslinking kinetics of epoxy resin with polyamine adducts is described in this study. A new epoxy formulation based on the use of polyamine adducts as the hardeners was analyzed. Crosslinking reactions of the different stoichiometric mixtures of the unmodified GY250 epoxy resin with the aliphatic EH606 and the cycloaliphatic EH637 polyamine adducts were studied using mid FT-IR spectroscopic techniques. As the crosslinking proceeded, the primary amine groups in polyamine adduct are converted to secondary and the tertiary amines. The decrease in the IR band intensity of epoxy groups at about 915 cm(-1), as well as at about 3,056 cm(-1), was observed due to process. Mid IR spectral analysis was used to calculate the content of the epoxy groups as a function of crosslinking time and the crosslinking degree of resin. The amount of all the epoxy species was estimated from IR spectra to changes during the crosslinking kinetics of epichlorhydrin.

Diagnostic relevance of ADAMTS13 activity: evaluation of 28 patients with thrombotic thrombocytopenic purpura - hemolytic uremic syndrome clinical diagnosis.

INTRODUCTION: The significance of ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motif-13) activity for diagnosis and therapy of thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) is still a controversial issue. OBJECTIVE: The aim of this report was to analyze the value of ADAMTS13 measurements in the diagnosis of TTP and HUS. METHODS: At presentation, we analyzed patients with idiopathic TTP (n = 18), secondary TTP (n = 4), diarrhea positive HUS (n = 3) and diarrhea negative HUS (n = 3) treated in Belgrade, Serbia from 2004 to 2010. ADAMTS13 activity from acute phase samples was measured using the residual collagen binding activity assay at the Haemophilia and Thrombosis Centre, Milan, Italy. RESULTS: There was a significant correlation between reduced ADAMTS13 activity and idiopathic TTP diagnosis (p = 0.000) as well as between lower ADAMTS13 activities and higher reticulocytes (p = 0.017) and lactate dehydrogenase levels (p = 0.027). Significant correlation was also found between higher protease activity and diagnosis of HUS (p = 0.000). There was a statistically significant correlation between higher ADAMTS13 activities and higher platelets count (p = 0.002), blood urea nitrogen (p = 0.000), and creatinine level (p = 0.000). CONCLUSION: Severe ADAMTS13 deficiency points at the diagnosis of idiopathic TTP and it is present in the secondary TTP but not in HUS.

Clinical experience in treatment of thrombotic thrombocytopenic purpura--hemolytic uremic syndrome with 28 patients.

BACKGROUND: Neither optimal treatment nor significance of ADAMTS13 (A Desintegrin And Metalloprotease with ThromboSpondin type 1 repeats) activity for diagnosis and therapy of thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome (HUS) have not been defined yet. The aim of the report is to analyze response to different volumes of plasma exchange (PE), and relationship to ADAMTS13. DESIGN AND METHODS: 28 patients clinically diagnosed with idiopathic TTP (n = 18), secondary TTP (n = 4), atypical HUS (n = 3) and typical HUS (n = 3) manifested 31 acute episodes. Patients were treated with PE in 26, and with plasma transfusion in 5 episodes with additional different therapies. RESULTS: PE volumes were as follows: 1 in 7, 1.5 in 3, 2 in 14, and intensifying schedule (1 to 1.5) in 2 episodes. Procedure number was lower in patients treated with 2 and 1.5 (p = 0.019) than in those treated with 1 volume exchange and PE intensifying, respectively (p = 0.010). PE response rate was 25/26 (96.15%). Exacerbation frequency was higher in idiopathic TTP patients (3/19) treated with 1 compared with patients treated with > 1 volume exchange (p = 0.003). Survival rate was 25/28 (89.29%). ADAMTS13 activity was reduced in 22 with severe deficiency in 14 patients. CONCLUSION: Patients responded to different treatments regardless of ADAMTS13 activity, requiring less PEs with larger volume exchanges.

[Hepatosplenic candidiasis in acute leukaemia patients].

INTRODUCTION: Hepatosplenic candidiasis is a disseminated invasive fungal infection that may affects patients with acute leukaemia. The main clinical manifestation is a persistent fever in patients recovered from prolonged neutropenia after recent chemotherapy. CASE OUTLINE: The authors present three patients, two women and one men, aged 23, 26 and 33 years, with acute leukaemia; one with acute myeloblastic and two with acute lymphoblastic leukaemia who developed hepatosplenic candidiasis. The diagnosis was based on prolonged fever, elevated serum bilirubin and alkaline phosphatase, as well as characteristic lesions on computed tomography, nuclear magnetic resonance and ultrasonographic findings and positive blood culture in one patient. The antifungal treatment was successful in one patient only. Two patients died due to progression of leukaemia. CONCLUSION: If leukaemia patient in remission after chemotherapy develops a prolonged fever of unknown origin, hepatosplenic candidiasis has to be considered and all efforts should be done to diagnose it. The diagnosis is based on clinical presentation and imaging techniques. The positive cultures of fungi are not usually possible and are not mandatory. The antifungal treatment may be prolonged, sometimes 2 to 3 months or even more.

Size of the protein-coding genome and rate of molecular evolution.

In diploid populations of size N, there will be 2 Nmu mutations per nucleotide (nt) site (or per locus) per generation (mu stands for mutation rate). If either the population or the coding genome double in size, one expects 4 Nmu mutations. What is important is not the population size per se but the number of genes (coding sites), the two being often interconverted. Here we compared the total physical length of protein-coding genomes (n) with the corresponding absolute rates of synonymous substitution (K(S)), an empirical neutral reference. In the classical occupancy problem and in the coupons collector (CC) problem, n was expressed as the mean rate of change (K(CC)). Despite inherently very low power of the approaches involving averaging of rates, the mode of molecular evolution of the total size phenotype of the coding genome could be evidenced through differences between the genomic estimates of K(CC) [K(CC)=1/(ln n + 0.57721) n] and rate of molecular evolution, K(S). We found that (1) the estimates of n and K(S) are reciprocally correlated across taxa (r=0.812; p<< 0.001); (2) the gamete-cell division hypothesis (Chang et al. Proc Natl Acad Sci USA 91:827-831, 1994) can be confirmed independently in terms of K(CC)/K(S) ratios; (3) the time scale of molecular evolution changes with change in mutation rate, as previously shown by Takahata (Proc Natl Acad Sci USA 87:2419-2423, 1990), Takahata et al. (Genetics 130:925-938, 1992), and Vekemans and Slatkin (Genetics 137:1157-1165, 1994); (4) the generation time and population size (Lynch and Conery, Science 302:1401-1404, 2003) effects left their "signatures" at the level of the size phenotype of the protein-coding genome.

[Treatment of 36 cases of thrombotic thrombocytopenic purpura]. / Rezultati lecenja trombozne trombocitopenijske purpure na 36 bolesnika.

Thirty-six patients (pts.) with thrombotic thrombocytopenic purpura (TTP) were treated between May 1990 and May 2003. There were 31 women and 5 men; the average age was 37 years. Twenty-five cases were idiopathic and 11 secondary (3 infection--related, 5 occurred during pregnancy and 3 were drug--associated). The mean lag period between the first symptoms and the diagnosis was 8.5 days (in 14 pts. < or = 5; in 22 > 5). On diagnosis neurological symptoms were present in 31, bleeding in 33, fever in 21 and renal impairment in 27 patients. The mean hemoglobin was 67.5 g/L, the mean platelet count was 10 x 10(9)/L, and the mean reticulocytosis was 17%. The mean serum LDH was 1457 IU. Treatment included plasma exchange (PE) in 24 pts. and only plasma infusions in 12 pts. There were 24 complete responders (20 on PE) and 12 deaths (4 on PE); PE significantly improved survival (p < 0.01). There were 5 treatment-related complications due to the infection and bleeding, 17 exacerbations and 4 relapses. The mean time delay before the onset of symptoms and the treatment initiation lasted for 9 days suggesting the poor disease recognition; the mean time delay from diagnosis to PE institution was 6 days, indicating postponed PE. The mean treatment duration in all patients was 18 days; the mean number of PE cycles needed for the platelet count stabilization was 9. Good prognostic indicators of survival were: the longer prodromal period (> 5 days), the secondary form of TTP and the absence of coma at presentation. The use of PE significantly improved survival. TTP is a severe disorder requiring early recognition and diagnosis in general medical care facilities, which should lead to the timely treatment with PE.