Kinga Sałapa

Met-enkephalins in patients with inflammatory bowel diseases

PURPOSE Opioid peptides provide a link between the neuroendocrine and immune systems. They modify the inflammatory process through their effect on the synthesis and secretion of cytokines and on the proliferation of leukocytes to the inflammatory lesion. The evaluation analyzed changes in free met-enkephalin concentration values in the serum and colon mucosal biopsy specimens of patients with inflammatory bowel disease (IBD). MATERIAL AND METHODS In serum and colon mucosal biopsy specimens, free met-enkephalin levels were determined in 43 patients with ulcerative colitis (UC) and 38 individuals with Crohns disease (CD). The evaluation analyzed the effect of disease activity, inflammatory lesions of the colon and laboratory parameters, on the level of the investigated marker. The control group consisted of 45 healthy volunteers. RESULTS Serum free met-enkephalin levels were depressed in patients with CD (85.4pg/ml) and UC (101.5pg/ml) as compared to the controls (119.4pg/ml). Met-enkephalin levels in colonic biopsies collected from inflammatory lesions in IBD patients were significantly higher as compared to sections without inflammatory lesions (6.59pg/mg vs. 2.89pg/mg, p < 0.01 in the CD group and 6.12pg/mg vs. 3.47pg/mg, p < 0.05 in the UC group) and their level correlated with disease activity. CONCLUSIONS The present investigation is the first study that demonstrates changes in free met-enkephalin levels in IBD that may play a role in the pathogenesis and course of the disease. Further studies are necessary to assess the anti-inflammatory effect of opioid peptides.

Reduced plasma fibrin clot permeability and susceptibility to lysis in patients with inflammatory bowel disease: a novel prothrombotic mechanism.

Background:Inflammatory bowel disease (IBD) is associated with an increased risk of thromboembolism. Its mechanism is still unclear. Altered fibrin clot properties have been reported in patients with thromboembolism and those with chronic inflammatory states. We investigated whether fibrin characteristics are abnormal in IBD. Methods:Ex vivo plasma fibrin clot permeability (Ks), compaction, turbidity, and efficiency of fibrinolysis were assessed in 85 consecutive patients with IBD, including 47 with ulcerative colitis (UC) and 38 with Crohns disease (CD), all with no history of thromboembolism. Forty-eight patients matched for age and sex served as controls. Results:Compared with controls, patients with UC and CD had 29.5% and 35.7% lower Ks associated with 13.8% and 23.1% lower compaction, respectively (all P < 0.001). Patients with UC and CD had higher maximum clot absorbance (+8.9%, P = 0.008, and +15.2%, P < 0.0001, respectively), higher maximum D-dimer released from clots (D-Dmax, +27.0%, P = 0.01, and +28.7%, P < 0.0001, respectively), and prolonged clot lysis time (+19.0%, P < 0.0001, and +25.5%, P < 0.0001, respectively). Lag phase was similar in both group of patients. D-Dmax was the only parameter that differed between patients in the UC and CD groups, being higher in CD (P = 0.04). The multiple linear regression model showed that in patients with UC, but not with CD, Ks, compaction, lysis time, and D-Dmax were all independently associated with disease activity. In patients with CD, Ks and lysis time were independently predicted by fibrinogen and C-reactive protein. Conclusions:Both UC and CD are characterized by formation of dense fibrin networks relatively resistant to lysis. Prothrombotic clot phenotype might represent a novel mechanism increasing thrombotic risk in IBD.

Disordered eating among mothers of Polish patients with eating disorders.

Summary Background The aim of this study was to assess attitudes towards eating as measured by the Eating Attitude Test (EAT26) among mothers of girls diagnosed with various types of eating disorders, in comparison with mothers of depressive girls and their relationship with daughters’ results 14 years after the beginning of the Polish political and cultural transformation of 1989. Material/Methods The data of 68 mothers and their daughters were used in statistical analysis (anorexia nervosa restrictive type: 18, anorexia nervosa binge/purge type: 12, bulimia: 14, depression: 24). The mean age in the group of mothers was 43.5 (SD 5.3), daughters: 16.7 (SD 1.4). Results In the group of mothers, the results of EAT26 test were lower than results of the general population of Polish females or patients’ mothers obtained in a different cultural context. Results from girls with an eating disorder diagnosis considerably exceed the mean result of Polish population studies of teenagers. There were no statistically significant differences between the EAT26 results of mothers of girls with various types of eating disorders and mothers of depressive girls. Sociocultural variables such as education and place of residence of mothers also did not differentiate the studied groups and did not have a significant influence on attitudes towards weight and body shape presented by the studied mothers. Conclusions The obtained results may suggest that in the studied population, the social background of mothers and disturbances of their own mothers’ attitudes towards weight and body shape were not an important and specific risk factor in the development of their daughters’ eating disorders.

Activated factor XI and tissue factor in inflammatory bowel disease

To the Editor: The risk of thromboembolic events is 3 to 4-fold higher in patients with inflammatory bowel disease (IBD) than in the general population.1 Venous thromboembolism in IBD occurs usually during exacerbation mainly in patients with more advanced complicated forms of the disease.1 The mechanisms underlying the link of IBD and thromboembolism involve endothelial injury, procoagulant effects of enhanced inflammation, hyperhomocysteinemia, and genetic predisposition.2 Typical prothrombotic abnormalities reported in IBD include elevated fibrinogen, factors (F)V, FVIII, FIX, FXIII, impaired fibrinolysis as well as reduced anticoagulant proteins such as protein S.2,3 Recently, it has been suggested that arterial thrombosis is more prevalent in IBD than in the general population.4 Tissue factor (TF) is the main initiator of blood coagulation in vivo. Although it has been suggested that circulating TF-bearing microparticles are elevated in IBD like in other inflammatory disorders,5 to our knowledge there have been no reports regarding TF levels in Crohn’s disease (CD) or ulcerative colitis (UC) patients. Moreover, increased active FXI (FXIa) levels that are known to confer a higher risk of venous and arterial thrombosis,6 have been observed in patients with active UC.5 No data on FXIa in CD have been published yet. To evaluate a potential role of procoagulant activity of TF and FXIa, we studied 80 consecutive IBD patients (39M, 41F) aged 34.5±12.1 years (±SD) (range 18 to 69), including 34 subjects with CD and 46 with UC. Active disease was observed at the time of enrollment in 19 CD patients (mean activity 169.2±93.5) and 26 UC assessed using a variation of the Truelove-Witts criteria (mean activity 5.45±3.35). Exclusion criteria were as follows: any acute illness, cancer, hepatic or renal dysfunction, previous venous thromboembolism, MI or stroke, oral anticoagulation or heparin administration. The Jagiellonian University Ethical Committee approved the study, and patients provided written, informed consent. To determine FXIa and TF in fasting citrated plasma, we used inhibitory monoclonal anti-FXI (αFXI-2) and anti-TF (αTF-5) antibodies at a final 0.1 mg/ml concentration and measured clotting time as previously described.7 The quantitation limit of our TF activity assay is 0.4 pM and that of FXIa assay is 10 pM. Age- and sex-matched healthy individuals (n=12) recruited from the hospital staff showed no detectable TF or FXIa. To assess thrombin generation in plasma, we determined thrombin-antithrombin complexes (TAT) using an ELISA (Dade Behring, Marburg, Germany). Quantifiable amounts (>10 pM) of plasma FXIa were detected in 53 of 80 (66%) patients with IBD. The concentration of FXIa varied from 17 to 156 pM with an average value of 57.2±33.6 pM. Detectable plasma TF activity was displayed in 27 of 80 (34%) IBD patients, all of whom also had circulating FXIa in plasma. Only 10 IBD patients had TF activity above 0.5 pM in the range from 0.6 to 5.1 pM. The concentration of TF in the remaining samples was below 0.4 pM. TF-positive patients did not differ from those not displaying detectable TF activity in plasma with regard to demographics, fibrinogen, C-reactive protein, creatinine, and disease activity (data not shown). This also held true for FXIa-positive and -negative patients with IBD except for age: the patients with detectable FXIa were older (36.6±12.7 years) than those with no FXIa (30.7±10.0 years, p=0.028). Importantly, plasma TAT correlated with FXIa in IBD (r2=0.49, p<0.001). The highest TAT levels were observed in patients with both detectable active TF and FXIa (7.8±2.2 µg/L); patients with FXIa but no detectable TF had a significantly lower amount (6.1±2.1 µg/L); and the patients with neither FXIa nor TF had the lowest levels (3.4±0.7 µg/L, p<0.05 for all comparisons) of TAT. This study is the first to demonstrate that as many as ⅔ of IBD patients had circulating FXIa and ⅓ had active TF in their plasmas, with no differences between CD and UC. Previously, we have shown that 96% of patients with acute myocardial infarction (AMI) and 76% of subjects with a history of MI have circulating FXIa.7 38% of AMI patients and only 6% of stable CAD patients showed detectable TF activity.7 In the current study, circulating levels of TF in the IBD patients were similar to those in acute coronary ischemia, whereas FXIa coagulant activity was only slightly lower compared to that observed in stable angina subjects who survived AMI.7 A correlation between thrombin generation (TAT) and FXIa activity confirms that, most likely, thrombin, not the contact pathway, accounts for FXI activation in this disease. These abnormalities may predispose to venous thrombosis and arterial thromboembolic events observed in CD and UC patients. Of note is that the presence of measurable TF and FXIa did not correlate with clinical activity of IBD or with inflammatory markers, suggesting a novel mechanism of thrombosis. This might in part explain clinical observations indicating that in UC an increased risk of thrombosis is observed in the mild form of disease or even during remission.1

In silico Structural Study of Random Amino Acid Sequence Proteins Not Present in Nature

The three‐dimensional structures of a set of ‘never born proteins’ (NBP, random amino acid sequence proteins with no significant homology with known proteins) were predicted using two methods: Rosetta and the one based on the ‘fuzzy‐oil‐drop’ (FOD) model. More than 3000 different random amino acid sequences have been generated, filtered against the non redundant protein sequence data base, to remove sequences with significant homology with known proteins, and subjected to three‐dimensional structure prediction. Comparison between Rosetta and FOD predictions allowed to select the ten top (highest structural similarity) and the ten bottom (the lowest structural similarity) structures from the ranking list organized according to the RMS‐D value. The selected structures were taken for detailed analysis to define the scale of structural accordance and discrepancy between the two methods. The structural similarity measurements revealed discrepancies between structures generated on the basis of the two methods. Their potential biological function appeared to be quite different as well. The ten bottom structures appeared to be ‘unfoldable’ for the FOD model. Some aspects of the general characteristics of the NBPs are also discussed. The calculations were performed on the EUChinaGRID grid platform to test the performance of this infrastructure for massive protein structure predictions.

“Fuzzy oil drop” model applied to individual small proteins built of 70 amino acids

The proteins composed of short polypeptides (about 70 amino acid residues) representing the following functional groups (according to PDB notation): growth hormones, serine protease inhibitors, antifreeze proteins, chaperones and proteins of unknown function, were selected for structural and functional analysis. Classification based on the distribution of hydrophobicity in terms of deficiency/excess as the measure of structural and functional specificity is presented. The experimentally observed distribution of hydrophobicity in the protein body is compared to the idealized one expressed by a three-dimensional Gauss function. The differences between these two distributions reveal the specificity of structural/functional characteristics of the protein. The residues of hydrophobicity deficiency versus the idealized distribution are assumed to indicate cavities with the potential to bind ligands, while the residues of hydrophobicity excess are interpreted as potentially participating in protein-protein complexation. The distribution of hydrophobicity irregularity seems to be specific for particular structures and functions of proteins. A comparative analysis of such profiles is carried out to identify the potential biological activity of proteins of unknown function.

Speaker identification based on artificial neural networks. Case study: the Polish vowel (pilot study)

Abstract Current statistical methods and technologies used for speaker identification via dynamic formant frequency often involve classic multivariate analyses that must meet a number of criteria in order to be considered trustworthy. The authors propose more advanced classification techniques, including artificial neural networks. Owing to iterative learning algorithms, neural networks can be trained to detect highly complex, nonlinear relations hidden in input data. This study specifically considers feed-forward multilayer perceptron and radial basic function network models. The investigation involves an analysis of the Polish vowel (stressed or unstressed) in selected contexts described by the four lowest formant frequencies. Results indicate high accuracy of neural networks as a speaker identification tool reaching up to 100%. In addition, the authors have determined that the accuracy of classification is similar when based on a single context to when input data are aggregated over several different contexts.

Measurement of hydrophobicity distribution in proteins – non-redundant Protein Data Bank

Abstract The cluster analysis is applied to the analysis of the data describing the status of protein structure in respect to hydrophobic core characteristics. The analysis revealed presence of two clusters distinguishing the proteins accordant with the “fuzzy oil drop” model and those which appear as discordant in respect to this model. The analysis was performed separately for chains treated as structural unit and for units defined according to IV-order (taking the functional protein complex). The characteristics of these two classification system appeared to differ in respect to number of proteins belonging to each of two clusters as well as relation between them.

Measuring core temperature using the proprietary application and thermo-smartphone adapter

Fast and accurate measurement of core body temperature is crucial for accidental hypothermia treatment. We have developed a novel light and small adapter to the headset jack of a mobile phone based on Android. It has been applied to measure temperature and set up automatic notifications (e.g. Global Positioning System coordinates to emergency services dispatcher, ECMO coordinator). Its validity was confirmed in comparison with Vital Signs Monitor Spacelabs Healthcare Elance 93300 as a reference method, in a series of 260 measurements in the temperature range of 10–42 °C. Measurement repeatability was verified in a battery of 600 measurements (i.e. 100 readings at three points of 10, 25, 42 °C for both esophageal and tympanic catheters). Inter-method difference of ≤0.5 °C was found for 98.5% for esophageal catheter and 100% for tympanic catheter measurements, with concordance correlation coefficient of 0.99 for both. The readings were almost completely repeatable with water bath measurements (difference of ≤0.5 °C in 10 °C: 100% for both catheters; in 25 °C: 99% for esophageal catheter and 100% tympanic catheter; in 42 °C: 100% for both catheters). This lightweight adapter attached to smartphone and standard disposable probes is a promising tool to be applied on-site for temperature measurement in patients at risk of hypothermia.

Geometry of Koch's triangle

Aims The first aim of this study was to determine the size of the Kochs triangle. The second one was to investigate relation between its dimensions and other individual-specific and heart-specific parameters as well as to create universal formula to estimate triangle dimensions based on these parameters. Methods and results This study is a prospective one, presenting 120 randomly selected autopsied hearts dissected from adult humans (Caucasian) of both sexes (31.7% females), with mean age of 49.3 ± 17.4 years. The length of triangle sides and angles were measured and the triangle area was calculated as well. Sixteen additional heart parameters were measured in order to analyse potential relationship between the dimensions of Kochs triangle and other dimensions of the heart, using linear regression analysis. The mean (±SD) length of the anterior edge was approximated to 18.0 ± 3.8 mm, the posterior edge to 20.3 ± 4.3 mm, and the basal edge to 18.5 ± 4.0 mm. The average values of the apex angle, the Eustachian angle, and the septal leaflet angle were 58.0 ± 14.4°, 53.8 ± 10.6°, and 67.6 ± 14.4°, respectively. The mean value of the Kochs triangle area was 151.5 ± 55.8 mm2. The 95th percentile of triangles height (the distance from the apex to the coronary sinus) was 21.8 mm. Conclusion Mean values and proportions of triangles sides and angles were presented. Kochs triangle showed considerable individual variations in size. The dimensions of the triangle were strongly independent from individual-specific and heart-specific morphometric parameters; however, the maximum triangles height can be estimated as 22 mm.