103 research outputs found
UV Fingerprints Predominate in the PTCH Mutation Spectra of Basal Cell Carcinomas Independent of Clinical Phenotype
Basal cell carcinoma (BCC) shows a wide interpatient variation in lesion accrual. To determine whether certain tumorigenic fingerprints and potentially predisposing patched (PTCH) tumor suppressor single-nucleotide polymorphisms (SNPs) are distributed differently among sporadic BCC patients, we compared the PTCH mutation spectra in early-onset BCC (first lesion at age <35 years), regular BCC (first lesion at age â„35 years and <10 lesions), and multiple BCC (â„10 lesions). The PTCH gene was mutated in 29 of 60 cases (48%). Most of the PTCH mutations bore the UV fingerprint (i.e., C â T or tandem CC â TT transitions at dipyrimidine sites). However, neither the proportion nor the spectra of exonic PTCH mutations differed significantly among the three groups. A large number of SNPs (IVS10+99C/T, IVS11-51G/C, 1665T/C, 1686C/T, IVS15+9G/C, IVS16-80G/C, IVS17+21G/A, and 3944C/T or its combinations) were also detected, but again their incidence did not differ significantly among the groups. Interestingly, expression of the IVS16-80G/C and the IVS17+21G/A genotype did not achieve the HardyâWeinberg equilibrium in patients with regular and/or early-onset BCC. These data suggest that a (UV-) mutated PTCH gene is important for sporadic BCC formation independent of clinical phenotype and that the IVS16-80G/C and/or IVS17+21G/A SNP site might be important for tumorigenesis in certain BCC patients
Assay validity of point-of-care platelet function tests in thrombocytopenic blood samples
Point-of-care (POC) platelet function tests are faster and easier to perform than in-depth assessment by flow cytometry. At low platelet counts, however, POC tests are prone to assess platelet function incorrectly. Lower limits of platelet count required to obtain valid test results were defined and a testing method to facilitate comparability between different tests was established.
We assessed platelet function in whole blood samples of healthy volunteers at decreasing platelet counts (> 100, 80-100, 50-80, 30-50 and < 30 x109/L) using two POC tests: impedance aggregometry and in-vitro bleeding time. Flow cytometry served as the gold standard. The number of platelets needed to reach 50% of the maximum function (ED50) and the lower reference limit (EDref) were calculated to define limits of test validity.
The minimal platelet count required for reliable test results was 100 x109/L for impedance aggregometry and in-vitro bleeding time but only 30 x109/L for flow cytometry. Comparison of ED50 and EDref showed significantly lower values for flow cytometry than either POC test (P value < 0.05) but no difference between POC tests nor between the used platelet agonists within a test method.
Calculating the ED50 and EDref provides an effective way to compare values from different platelet function assays. Flow cytometry enables correct platelet function testing as long as platelet count is > 30 x109/L whereas impedance aggregometry and in-vitro bleeding time are inconsistent unless platelet count is > 100 x109/L
Testing lupus anticoagulants in a real-life scenario - a retrospective cohort study
Introduction: Lupus anticoagulant (LAC) testing is challenging. Most data are derived from a well-controlled study environment with potential
alterations to daily routines. The aim of this retrospective cohort study was to assess the capacity of various LAC screening tests and derived mixing
tests to predict a positive result in subsequent confirmation tests in a large cohort of patients.
Materials and methods: In 5832 individuals, we retrospectively evaluated the accuracy of the aPTT-A, aPTT-LAscreen, aPTT-FS and dRVVTscreen
and of their derived mixing tests in detecting a positive confirmation test result within the same blood specimen. The group differences, degree of
correlation and the predictive accuracy of LAC coagulation tests were analysed using the Mann-Whitney U test, the Spearman-rank-correlation and
by area under the receiver operating characteristic curve (ROC-AUC) analysis. ROC-AUCs were compared with the VenkatramanÂŽs permutation test.
Results: The pre-test probability of patients with clinically suspected LAC was 36% in patients without factor deficiency or anticoagulation therapy.
The aPTT-LAscreen showed the best diagnostic accuracy with a ROC-AUC of 0.84 (95% CI: 0.82 â 0.86). No clear advantage of the dRVVT-derived
mixing test was detectable when compared to the dRVVTscreen (P = 0.829). Usage of the index of circulating anticoagulant (ICA) did not improve the
diagnostic power of respective mixing tests.
Conclusions: Among the parameters evaluated, aPTT-LAscreen and derived mixing test parameters were the most accurate tests. In our study cohort,
neither other mixing test nor the ICA presented any further advantage in LAC diagnostics
Superficial thrombophlebitis and risk for recurrent venous thromboembolism
AbstractObjective: Superficial thrombophlebitis (ST) is a frequent and potentially serious disease if complicated with venous thromboembolism (VTE). Data on risk factors and incidence rates for ST are scarce. It is also unknown whether ST is a risk factor for recurrence of VTE. Methods: After discontinuation of secondary thromboprophylaxis for a first spontaneous VTE, we prospectively observed 615 patients on average for 30 ± 26 months. Patients with natural coagulation inhibitor deficiency, lupus anticoagulant, or cancer, who were pregnant, or were receiving long-term antithrombotic therapy were excluded. The study outcomes were occurrence of symptomatic ST or objectively documented recurrent symptomatic VTE. Results: ST developed in 45 patients (7.3%) with a first VTE. High factor VIII concentration emerged as an independent risk factor for ST (relative risk [RR], 2.0; 95% confidence interval [CI], 1.0-5.2), compared with lower levels after adjustment for age and sex; factor V Leiden and prothrombin G20210A concentration; hyperhomocysteinemia; high body mass index; and duration of oral anticoagulation therapy. VTE recurred in 12 (27%) of 45 patients with ST and in 67 (12%) of 570 patients without ST. In patients with VTE, subsequent ST emerged as an independent risk factor for recurrent VTE. Patients with ST had twofold higher RR (2.1; 95% CI, 1.0-4.2) for recurrence than did patients without ST after adjustment for putative confounding variables. Conclusion: Patients with a first spontaneous VTE and subsequent ST are at increased risk for recurrent VTE. High factor VIII concentration is an independent risk factor for ST. (J Vasc Surg 2003;37:834-8.
Characterization of a prothrombotic phenotype using thrombin generation and thrombin activity in cirrhosis and portal hypertension
Background: Patients with advanced chronic liver disease (ACLD) may develop a prothrombotic phenotype that seems to be more pronounced with more severe liver dysfunction. An imbalance of endogenous pro- and anticoagulants is not fully captured by routine coagulation assays. Methods: In a cohort of ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement, we assessed thrombin generation (TGA) using two commercially available assays (Technothrombin and Thrombinoscope) with and without addition of soluble thrombomodulin (TM), as well as thrombin activity, alongside a panel of coagulation parameters. Results: The cohort encompassed 37 patients (median age 55.3 years, mean HVPG 16 ± 5 mm Hg). In the TM-modified Thrombinoscope TGA, the endogenous thrombin generation potential (ETP) was significantly increased in Child-Pugh-Score (CPS) B/C patients (N = 23, 62 %) compared to CPS A patients (N = 14, 38 %) (ETP: 546 nMâmin (443â696) vs. 404 nMâmin (289â573), p = 0.028). Using the Technothrombin TGA without TM, patients with CPS B/C had decreased ETP compared to CPS A patients (ETP: 2792 ± 1336 nMâmin vs. 5040 ± 816 nMâmin, p < 0.001) and with addition of TM (final concentration: 5 nM; ETP: 2545 ± 1327 nMâmin vs. 4824 ± 929 nMâmin, p < 0.001). Thrombin activity levels were 0.6pM in median (0.2â1.6pM) and above the level of detectability (0.10pM) in 94.6 % of patients but were not correlated to severity of cirrhosis (CPS A 0.7pM vs CPS B/C 0.4pM, p = 0.377) nor to parameters of TGA. Conclusion: Thrombin plasma levels are elevated in liver disease patients without apparent correlation to TGA or severity of cirrhosis. TGAs can be modified with TM to enable protein C-dependent anticoagulation, but result in differences with regard to severity of liver disease.</p
Design Management Program Application for Internet Access in STMIK Jakarta Pusyanet
A medium used for the general course requires management to continuity ofoperations, not much different from the means of Internet access that is intended forstudents STMIK Jakarta. By using application programs created with Visual Basiclanguage, management of user identities, the use and timing of each user requests alist of all of them are stored in the database using Microsoft Access
Characterization of a prothrombotic phenotype using thrombin generation and thrombin activity in cirrhosis and portal hypertension
Background: Patients with advanced chronic liver disease (ACLD) may develop a prothrombotic phenotype that seems to be more pronounced with more severe liver dysfunction. An imbalance of endogenous pro- and anticoagulants is not fully captured by routine coagulation assays. Methods: In a cohort of ACLD patients undergoing hepatic venous pressure gradient (HVPG) measurement, we assessed thrombin generation (TGA) using two commercially available assays (Technothrombin and Thrombinoscope) with and without addition of soluble thrombomodulin (TM), as well as thrombin activity, alongside a panel of coagulation parameters. Results: The cohort encompassed 37 patients (median age 55.3 years, mean HVPG 16 ± 5 mm Hg). In the TM-modified Thrombinoscope TGA, the endogenous thrombin generation potential (ETP) was significantly increased in Child-Pugh-Score (CPS) B/C patients (N = 23, 62 %) compared to CPS A patients (N = 14, 38 %) (ETP: 546 nMâmin (443â696) vs. 404 nMâmin (289â573), p = 0.028). Using the Technothrombin TGA without TM, patients with CPS B/C had decreased ETP compared to CPS A patients (ETP: 2792 ± 1336 nMâmin vs. 5040 ± 816 nMâmin, p < 0.001) and with addition of TM (final concentration: 5 nM; ETP: 2545 ± 1327 nMâmin vs. 4824 ± 929 nMâmin, p < 0.001). Thrombin activity levels were 0.6pM in median (0.2â1.6pM) and above the level of detectability (0.10pM) in 94.6 % of patients but were not correlated to severity of cirrhosis (CPS A 0.7pM vs CPS B/C 0.4pM, p = 0.377) nor to parameters of TGA. Conclusion: Thrombin plasma levels are elevated in liver disease patients without apparent correlation to TGA or severity of cirrhosis. TGAs can be modified with TM to enable protein C-dependent anticoagulation, but result in differences with regard to severity of liver disease.</p
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