60 research outputs found
The Partition Function of Multicomponent Log-Gases
We give an expression for the partition function of a one-dimensional log-gas
comprised of particles of (possibly) different integer charge at inverse
temperature {\beta} = 1 (restricted to the line in the presence of a
neutralizing field) in terms of the Berezin integral of an associated non-
homogeneous alternating tensor. This is the analog of the de Bruijn integral
identities [3] (for {\beta} = 1 and {\beta} = 4) ensembles extended to
multicomponent ensembles.Comment: 14 page
Right heart thrombosis in patients with pulmonary embolism: a case series
Currently, recommendations have been developed for the treatment of patients with pulmonary embolism. However, the optimal management tactics for such patients in the presence of right heart thrombosis remains a matter of argument. Timely detection of right heart thrombosis can influence the choice of treatment tactics, which will help reduce the risk of adverse outcomes. The article presents three clinical cases with different clinical course options and management strategies that take into account risk factors and prognosis
Efficacy of buffered and enteric-coated acetylsalicylic acid on platelet aggregation in patients with stable coronary artery disease and type 2 diabetes (CASCADE): rationale and design of a single-center observational comparative study
Aim. Enteric-coated acetylsalicylic acid (ASA) is released more slowly and is absorbed in smaller quantities and over a longer period of time, which may lead to bioavailability and antiplatelet effect decrease compared to conventional ASA. Patients with diabetes are characterized by increased platelet reactivity and a reduced pharmacodynamic response to ASA compared to individuals without diabetes. It seems rational to test the hypothesis that the use of ASA absorbed in the stomach may be more effective in patients with type 2 diabetes mellitus (T2D) and stable coronary artery disease (CAD).Material and methods. This single-center, non-interventional comparative study will randomly select 200 adult patients of both sexes with stable CAD and T2D who were routinely prescribed a gastro-soluble ASA (Cardiomagnyl 75 mg/day) or an enteric-soluble ASA (Aspirin® Cardio 100 mg/day or Thrombo ASS® 100 mg/day) before inclusion in the study. According to the routinely prescribed therapy, patients will be divided into 2 following groups: patients taking Cardiomagnyl 75 mg/day and patients taking Aspirin® Cardio 100 mg/day or Thrombo ASS® 100 mg/day. The primary endpoint is the incidence of high residual platelet reactivity (HRPR) while taking ASA (resistance to ASA) according to the VerifyNow Aspirin Test.Conclusion. CASCADE is the first study to evaluate the HRPR using the VerifyNow Aspirin Test in patients with stable CAD and T2D
Record linkage to obtain birth outcomes for the evaluation of screening biomarkers in pregnancy: a feasibility study
<p>Abstract</p> <p>Background</p> <p>Linking population health data to pathology data is a new approach for the evaluation of predictive tests that is potentially more efficient, feasible and efficacious than current methods. Studies evaluating the use of first trimester maternal serum levels as predictors of complications in pregnancy have mostly relied on resource intensive methods such as prospective data collection or retrospective chart review. The aim of this pilot study is to demonstrate that record-linkage between a pathology database and routinely collected population health data sets provides follow-up on patient outcomes that is as effective as more traditional and resource-intensive methods. As a specific example, we evaluate maternal serum levels of PAPP-A and free <it>β</it>-hCG as predictors of adverse pregnancy outcomes, and compare our results with those of prospective studies.</p> <p>Methods</p> <p>Maternal serum levels of PAPP-A and free <it>β</it>-hCG for 1882 women randomly selected from a pathology database in New South Wales (NSW) were linked to routinely collected birth and hospital databases. Crude relative risks were calculated to investigate the association between low levels (multiples of the median ≤ 5<sup>th </sup>percentile) of PAPP-A or free <it>β</it>-hCG and the outcomes of preterm delivery (<37 weeks), small for gestational age (<10<sup>th </sup>percentile), fetal loss and stillbirth.</p> <p>Results</p> <p>Using only full name, sex and date of birth for record linkage, pregnancy outcomes were available for 1681 (89.3%) of women included in the study. Low levels of PAPP-A had a stronger association with adverse pregnancy outcomes than a low level of free <it>β</it>-hCG which is consistent with results in published studies. The relative risk of having a preterm birth with a low maternal serum PAPP-A level was 3.44 (95% CI 1.96–6.10) and a low free <it>β</it>-hCG level was 1.31 (95% CI 0.55–6.16).</p> <p>Conclusion</p> <p>This study provides data to support the use of record linkage for outcome ascertainment in studies evaluating predictive tests. Linkage proportions are likely to increase if more personal identifiers are available. This method of follow-up is a cost-efficient technique and can now be applied to a larger cohort of women.</p
A Case Report of Differential Diagnosis of Causes of Severe Valvular Heart Disease (Takayasu's Arteritis, Infective Endocarditis and Myxomatous Degeneration) with the Key Role of Histological and PCR Examination
Aortic valve lesion is a common and may have diverse causes, from degenerative, congenital and infectious diseases to autoimmune conditions. We present a rare case of Takayasu arteritis and severe heart lesion due to the myxomatous degeneration of the aortic and mitral valves associated with development of infective endocarditis (IE) complicated by abscess, fistula, valve perforation and recurrent acute decompensated heart failure in a young female patient. A combined use of histopathological and PCR analyses of valve tissues was critically important for differential diagnosis of the valve lesions, as it made it possible to identify the true cause of the disease. The presence of Takayasu arteritis has played an indirect role by creating conditions for the development of immunosuppression and determining the disease severity and its progression
Coagulation disorders in myocardial infarction with nonobstructive coronary arteries
Aim. To investigate the state of the platelet and plasma components of hemostasis in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA).Material and methods. The study included 42 patients with non-ST-segment elevation myocardial infarction (NSTEMI): MINOCA (n=24) and MI-CAD (n=18). Platelet aggregation ability in response to activation was evaluated using Solar AP2110 and LASCA aggregometers. Platelet functional activity and calcium signaling were assessed using flow cytometry methods. The plasma component of hemostasis, in addition to routine coagulation tests was evaluated using the global coagulation test "Thrombodynamics". The control groups for tests consisted of healthy volunteers.Results. When analyzing the ability of platelets to form aggregates by the aggregometry tests, it was found that platelets in the MINOCA group formed aggregates significantly worse upon ADP stimulation at various concentrations compared to the MI-CAD group. However, when platelets were stimulated with collagen, the opposite effect was observed: in the MI-CAD group, there was a noticeable decrease in aggregate formation in terms of light scattering amplitude compared to the MINOCA group. Flow cytometry using the functional platelet activity test protocol revealed that both groups showed a significantly increased platelet size after activation, reduced platelet granularity) both at rest and upon activation, significantly decreased number of procoagulant phosphatidylserine-positive platelets, and reduced dense granule release upon activation compared to healthy volunteers. The calcium signaling test showed a weakened calcium release in response to ADP in the MINOCA group compared to the MI-CAD group. In the study of the plasma component, no significant differences between the groups or deviations were found according to both routine tests and the "Thrombodynamics" test.Conclusion. Platelet activity did not differ significantly between the MINOCA and MI-CAD groups; however, in the MINOCA group, platelet activity was lower in some tests compared to the MI-CAD group. In the study of the plasma hemostasis component, normocoagulation was recorded in both groups
Linking databases on perinatal health: a review of the literature and current practices in Europe
BACKGROUND: International comparisons of perinatal health indicators are complicated by the heterogeneity of data sources on pregnancy, maternal and neonatal outcomes. Record linkage can extend the range of data items available and thus can improve the validity and quality of routine data. We sought to assess the extent to which data are linked routinely for perinatal health research and reporting.
METHODS: We conducted a systematic review of the literature by searching PubMed for perinatal health studies from 2001 to 2011 based on linkage of routine data (data collected continuously at various time intervals). We also surveyed European health monitoring professionals about use of linkage for national perinatal health surveillance.
RESULTS: 516 studies fit our inclusion criteria. Denmark, Finland, Norway and Sweden, the US and the UK contributed 76% of the publications; a further 29 countries contributed at least one publication. Most studies linked vital statistics, hospital records, medical birth registries and cohort data. Other sources were specific registers for: cancer (70), congenital anomalies (56), ART (19), census (19), health professionals (37), insurance (22) prescription (31), and level of education (18). Eighteen of 29 countries (62%) reported linking data for routine perinatal health monitoring.
CONCLUSION: Research using linkage is concentrated in a few countries and is not widely practiced in Europe. Broader adoption of data linkage could yield substantial gains for perinatal health research and surveillance
Regional perinatal mortality differences in the Netherlands; care is the question
Background. Perinatal mortality is an important indicator of health. European comparisons of perinatal mortality show an unfavourable position for the Netherlands. Our objective was to study regional variation in perinatal mortality within the Netherlands and to identify possible explanatory factors for the found differences. Methods. Our study population comprised of all singleton births (904,003) derived from the Netherlands Perinatal Registry for the period 2000-2004. Perinatal mortality including stillbirth from 22+0weeks gestation and early neonatal death (0-6 days) was our main outcome measure. Differences in perinatal mortality were calculated between 4 distinct geographical regions North-East-South-West. We tried to explain regional differences by adjustment for the demographic factors maternal age, parity and ethnicity and by socio-economic status and urbanisation degree using logistic modelling. In addition, regional differences in mode of delivery and risk selection were analysed as health care factors. Finally, perinatal mortality was analysed among five distinct clinical risk groups based on the mediating risk factors gestational age and congenital anomalies. Results. Overall perinatal mortality was 10.1 per 1,000 total births over the period 2000-2004. Perinatal mortality was elevated in the northern region (11.2 per 1,000 total births). Perinatal mortality in the eastern, western and southern region was 10.2, 10.1 and 9.6 per 1,000 total births respectively. Adjustment for demographic factors increased the perinatal mortality risk in the northern region (odds ratio 1.20, 95% CI 1.12-1.28, compared to reference western region), subsequent adjustment for socio-economic status and urbanisation explained a small part of the elevated risk (odds ratio 1.11, 95% CI 1.03-1.20). Risk group analysis showed that regional differences were absent among very preterm births (22+0- 25+6weeks gestation) and most prominent among births from 32+0gestation weeks onwards and among children with severe congenital anomalies. Among term births (37+0weeks) regional mortality differences were largest for births in women transferred from low to high risk during delivery. Conclusion. Regional differences in perinatal mortality exist in the Netherlands. These differences could not be explained by demographic or socio-economic factors, however clinical risk group analysis showed indications for a role of health care factors
The Ubiquitin Peptidase UCHL1 Induces G0/G1 Cell Cycle Arrest and Apoptosis Through Stabilizing p53 and Is Frequently Silenced in Breast Cancer
Background: Breast cancer (BrCa) is a complex disease driven by aberrant gene alterations and environmental factors. Recent studies reveal that abnormal epigenetic gene regulation also plays an important role in its pathogenesis. Ubiquitin carboxyl- terminal esterase L1 (UCHL1) is a tumor suppressor silenced by promoter methylation in multiple cancers, but its role and alterations in breast tumorigenesis remain unclear. Methodology/Principal Findings: We found that UCHL1 was frequently downregulated or silenced in breast cancer cell lines and tumor tissues, but readily expressed in normal breast tissues and mammary epithelial cells. Promoter methylation of UCHL1 was detected in 9 of 10 breast cancer cell lines (90%) and 53 of 66 (80%) primary tumors, but rarely in normal breast tissues, which was statistically correlated with advanced clinical stage and progesterone receptor status. Pharmacologic demethylation reactivated UCHL1 expression along with concomitant promoter demethylation. Ectopic expression of UCHL1 significantly suppressed the colony formation and proliferation of breast tumor cells, through inducing G0/G1 cell cycle arrest and apoptosis. Subcellular localization study showed that UCHL1 increased cytoplasmic abundance of p53. We further found that UCHL1 induced p53 accumulation and reduced MDM2 protein level, and subsequently upregulated the expression of p21, as well as cleavage of caspase3 and PARP, but not in catalytic mutant UCHL1 C90Sexpressed cells
Investigating linkage rates among probabilistically linked birth and hospitalization records
- …
