Combined Regularized Discriminant Analysis and Swarm Intelligence Techniques for Gait Recognition.

In the gait recognition problem, most studies are devoted to developing gait descriptors rather than introducing new classification methods. This paper proposes hybrid methods that combine regularized discriminant analysis (RDA) and swarm intelligence techniques for gait recognition. The purpose of this study is to develop strategies that will achieve better gait recognition results than those achieved by classical classification methods. In our approach, particle swarm optimization (PSO), grey wolf optimization (GWO), and whale optimization algorithm (WOA) are used. These techniques tune the observation weights and hyperparameters of the RDA method to minimize the objective function. The experiments conducted on the GPJATK dataset proved the validity of the proposed concept.

Acute-phase response and its biomarkers in acute and chronic urticaria.

INTRODUCTION: Since urticaria is a persisting inflammatory disease it is important to establish the prognostic factors for the duration and severity of the disease. AIM: To evaluate serum concentrations of selected acute-phase proteins (APP) in patients with various forms of urticaria as compared to healthy volunteers and also to analyze these concentrations in different types of urticaria. Additionally, to evaluate the correlation between serum levels of selected APP and disease activity. MATERIAL AND METHODS: Serum concentrations of C-reactive protein (CRP), α1-acid glycoprotein (AGP), α1-antichymotrypsin (ACT), α1-antitrypsin (AT), ceruloplasmin (Cp), transferrin (Tf), α2-macroglobulin (α2M) and haptoglobin (Hp) were measured. Quantitative measurement was conducted using the rocket immunoelectrophoresis. Disease activity was assessed with the use of total symptom score. RESULTS: Analysis of serum APP concentrations revealed statistically higher serum concentrations of CRP, AGP and ACT in the entire group of patients with urticaria in comparison with the control group. In the entire group of patients with urticaria, CRP, AGP, ACT, Cp and Hp correlated positively with disease activity, intensity of pruritus and the number and size of urticarial wheals. Statistically lower serum concentrations of CRP, ACT, Cp and Hp were detected in the group of patients with acute urticaria (AU) and angioedema together, compared to the patients suffering from AU only. CONCLUSIONS: Patients with symptoms of various forms of urticaria present a distinct profile of serum APP concentrations. A significant correlation observed between CRP, AGP, ACT, Cp, Hp and clinical activity score points to the potential role of APP as markers of the urticarial activity.

The effect of electromagnetic field on reactive oxygen species production in human neutrophils in vitro.

The present study was undertaken in order to determine the effect of low frequency electromagnetic field (EMF) on reactive oxygen species (ROS) production in human neutrophils in peripheral blood in vitro. We investigated how differently generated EMF and several levels of magnetic induction affect ROS production. To evaluate the level of ROS production, two fluorescent dyes were used: 2'7'-dichlorofluorscein-diacetate and dihydrorhodamine. Phorbol 12-myristate 13-acetate (PMA), known as strong stimulator of the respiratory burst, was also used. Alternating magnetic field was generated by means of Viofor JPS apparatus. Three different levels of magnetic induction have been analyzed (10, 40 and 60 µT). Fluorescence of dichlorofluorescein and 123 rhodamine was measured by flow cytometry. The experiments demonstrated that only EMF tuned to the calcium ion cyclotron resonance frequency was able to affect ROS production in neutrophils. Statistical analysis showed that this effect depended on magnetic induction value of applied EMF. Incubation in EMF inhibited cell activity slightly in unstimulated neutrophils, whereas the activity of PMA-stimulated neutrophils has increased after incubation in EMF.

Reactive oxygen species (ROS) production in human peripheral blood neutrophils exposed in vitro to static magnetic field.

The aim of this study was to determine the effect of gradient static magnetic field (SMF) on reactive oxygen species (ROS) production in human neutrophils in peripheral blood in vitro. Blood samples collected from healthy individuals were incubated in an inhomogeneous SMF (in a south or north pole of the field) for 15, 30 or 45 minutes. The maximum value of induction (B max) amounted to ≈ 60 mT. To determine the strength of the ROS production, dihydrorhodamine (123DHR) as fluorophore and phorbol 12-myristate 13-acetate (PMA) as respiratory burst stimulator were used. 123DHR oxidation by ROS was measured by flow cytometry. The exposure of blood samples to SMF induced statistically significant changes in ROS production in unstimulated and PMA-stimulated neutrophils. The observed effects were highly correlated with the exposure time and depended on the orientation of the field. Although intracellular mechanisms underlying such interactions are not thoroughly understood, it could be presumed that SMF affects ROS metabolic oscillations and their formation and inactivation. This study emphasizes the importance of proper adjustment of exposure time to SMF for any potential therapeutic applications.

Ki-67 and p53 expression in ileal pouches.

Development of dysplastic lesions that may potentially lead to cancer is sometimes reported within the ileal pouches. Dysplasia is in turn associated with increased expression of proliferation indices. The goal of this study was to evaluate the mitotic activity and possible expression of p53 in the epithelium within the ileal pouches in patients with chronic ulcerative colitis. The study involved archive material consisting of ileal pouches surgically removed from 17 patients diagnosed with ulcerative colitis. Several specimens were collected from each pouch. The immunohistochemistry (Ki-67 and p53 protein) control group (14 cases) consisted of the resection line specimens of colons removed due to colorectal adenocarcinoma. Intensity of the expression of the markers under study within the inflammatory infiltrates was assessed using a 5-point scale proposed by Berstein et al. Ki-67 expression was observed in all studied patients with marked intensity (Bernstein scale score +3, +4). Protein p53 expression was observed only in eight patients, and was mostly of low intensity (Bernstein scale score +1, +2). Immunohistochemical results confirmed the histopathological results that revealed dysplastic lesions, which are often an indication for radical procedures in ulcerative colitis patients. Our results suggest the usefulness of these examinations, also in the ileal pouch material.

Pretransplant urine cytokine pattern predicts acute kidney rejection.

Acute rejection (AR) remains a major problem after kidney transplantation and crucial determinant of long-term graft function. Potent mediators of alloimmune response leading to AR are cytokines. To further explore the relation between cytokine pattern and frequency of AR episodes we analyzed Th1/Th2 cytokine concentrations in the urine of 44 patients prior to the kidney transplantation. During the 6-month period following the transplantation AR was diagnosed in 11 patients. Urine samples were collected 1day before the transplantation. Samples were cytometrically tested for concentrations of IL-2, IL-4, IL-5, IL-10, IFN-gamma and TNF-alpha. Analysis showed significantly higher pretransplant concentrations of IFN-gamma (P > .001), TNF-alpha (P < .05) and IL-10 (P < .001) in the urine of patients with diagnosed AR. No significant differences in the concentrations of IL-2, IL-4, IL-5 between the two groups were observed. Elevated pretransplant concentrations of urine IFN-gamma and TNF-alpha in AR patients, not accompanied by higher concentrations of IL-2, may suggest an ongoing undetected and local, non-specific Th1 immune response, capable of amplifying the alloimmune response in the early phase postsurgery. While higher concentrations of IL-10 can partially result from activation of monocytes/macrophages, and partially from peripheral regulatory mechanisms controlling the ongoing immune reaction.

[The assessment of acute phase proteins as prognostic factors in patients surgically treated for non-small cell lung cancer]. / Ocena wybranych bialek ostrej fazy jako czynników rokowniczych u chorych leczonych chirurgicznie z powodu niedrobnokomórkowego raka pluca.

INTRODUCTION: The aim of the study was to assess quantitative changes of the acute phase protein (APP) serum level in patients with non-small cell lung cancer (NSCLC) who underwent a radical resection. We analysed the correlation between quantitative APP changes and: the survival rate, the histological type of the cancer, TNM stage and grading. MATERIAL AND METHODS: We analysed a group of 46 patients surgically treated for NSCLC from 2003 to 2004. The average age of patients was 61 (45 to 77 years). The most frequent histological types of cancer were: squamous cell lung cancer (24 patients) and adenocarcinoma (17 patients). The majority of them were in stage II B (15 patients) and III A (14 patients). We analysed serum levels of: C-reactive protein (CRP), alpha1-acid glycoprotein (AGP), alpha1-antichymotrypsin (ACT), alpha1-antitrypsin (AT), alpha2-macroglobulin (M), ceruloplasmin (Cp), haptoglobin (Hp), and transferrin (Tf) by means of rocket immunoelectrophoresis by Laurell. RESULTS: The level of AT was significantly higher in patients with adenocarcinoma, as compared to other histological types of cancer. In the case of patients with squamous cell lung cancer, significantly higher M and Cp. We did not find any correlation between the APP level and grading. The levels of five APP: CRP, AGP, ACT, M and Cp were significantly higher in the group of patients with T3 or T4 category, while N1 or N2 status had significantly higher concentrations of AT, CRP and Hp. The multivariate analysis confirmed the influence of the following factors on long-term survival: N stage, histological type of cancer and preoperative serum levels of AGP and Hp. CONCLUSIONS: The serum concentration of some APP may correlate with the more aggressive clinical behavior of lung cancer. The patients with N1 or N2 stage of adenocarcinoma have significantly higher serum level of AT and the preoperative concentration of AGP and Hp correlates with the overall survival. These proteins could serve as prognostic factors in the risk assessment of the cancer recurrence after the surgical management.

[Transferrin microheterogeneity in patients treated by maintenance haemodialysis]. / Mikroheterogennosc transferyny u chorych leczonych powtarzana hemodializa.

Transferrin (Tf) plays a crucial role in iron transport in the human body. In physiologically status Tf occurs in four variants. The concentration of Tf and its variants is changing in several conditions, especially during acute phase response, which may take place in end-stage renal disease (ESRD). The aim of this study was the assessment of the associations between changes of glycosylation of transferrin and selected blood cell count and iron metabolism parameters in ESRD patients treated by maintenance hemodialysis (mHD) with long lasting anaemia despite treatment by rHuEPO. Studies were carried out on a group of 55 ESRD patients treated by HD (ESRD group). The reference values were obtained from a group of 20 healthy volunteers (HV group). The Tf concentration was determined by the rocket immunoelectrophoresis according to Laurell. To estimate the microheterogenity of Tf the crossed affinoimmunoelectrophoresis according to Bog-Hansen was used. The concentration of selected hematological variables, and selected liver metabolism variables was assessed by routine laboratory tests, while the concentration of cytokines was measured by ELISA method, and selected acute phase proteins, i.e. C-reactive protein, by immunonephelometry method. Tf in studied sera was divided into four variants Tf1, Tf2, Tf3, Tf4. The percentage contents of variants in HV was Tf1=4%, Tf2=9%, Tf3=82%, Tf4=4%. In the sera of ESRD group the percentage contents of the Tf1, Tf2, Tf4 variants increased to 9%, 16%, 10% respectively, while the Tf3 variant decreased to 65%. Serum concentration of Tf was lower (1441 +/- 526 mg/L) in ESRD patients (p<0.0001) vs. 3539 +/- 955 mg/L in HV group. During this study we have revealed that the quantity and the quality of Tf is changing in ESRD patients. The observed correlations between concentration of Tf3 and selected hematological variables and also between Tf3 and rHuEPO, suggests that the decrease concentration of the Tf3 may lead to an impaired iron transport to the cells and may be one of the factors affecting anaemia in patients treated by HD and rHuEPO.

Planning Training Loads for the 400 M Hurdles in Three-Month Mesocycles using Artificial Neural Networks.

This paper presents a novel approach to planning training loads in hurdling using artificial neural networks. The neural models performed the task of generating loads for athletes' training for the 400 meters hurdles. All the models were calculated based on the training data of 21 Polish National Team hurdlers, aged 22.25 ± 1.96, competing between 1989 and 2012. The analysis included 144 training plans that represented different stages in the annual training cycle. The main contribution of this paper is to develop neural models for planning training loads for the entire career of a typical hurdler. In the models, 29 variables were used, where four characterized the runner and 25 described the training process. Two artificial neural networks were used: a multi-layer perceptron and a network with radial basis functions. To assess the quality of the models, the leave-one-out cross-validation method was used in which the Normalized Root Mean Squared Error was calculated. The analysis shows that the method generating the smallest error was the radial basis function network with nine neurons in the hidden layer. Most of the calculated training loads demonstrated a non-linear relationship across the entire competitive period. The resulting model can be used as a tool to assist a coach in planning training loads during a selected training period.

Microheterogeneity of acute phase proteins in patients with ulcerative colitis.

AIM: To estimate the serum alpha1-antichymotrypsin (ACT), alpha1-acid glycoprotein (AGP) and transferrin (Tf) concentrations and to evaluate the microheterogeneity of these acute phase proteins in patients with ulcerative colitis. METHODS: Twenty-seven patients with ulcerative colitis (UC) and 17 healthy control subjects were studied. The patients were categorised as severe (n = 9), moderate (n = 10) and mild groups (n = 8) using Truelove and Witts' classification of ulcerative colitis. Microheterogeneity of ACT, AGP and Tf was analysed by crossed immunoaffinity electrophoresis (CIAE) with concanavalin A. In all serum samples standard electrophoresis of serum proteins was performed, iron (Fe) concentration, total iron binding capacity (TIBC) and C-reactive protein (CRP) were also measured. RESULTS: Our patients suffering from ulcerative colitis had significantly higher serum ACT and AGP concentrations and lower serum transferrin concentration in comparison to healthy subjects. Changes in concentrations of acute phase proteins were dependent on the activity of the inflammatory process. The glycosylation patterns of transferrin were related to the inflammation status. We also observed the correlation between ACT and AGP concentrations, patterns of transferrin glycosylation and changes in standard protein electrophoresis or blood cell count. CONCLUSION: The glycosylation patterns of transferrin obtained from patients suffering from ulcerative colitis are highly branched and sialylated compared with those obtained from healthy subjects. In contrast, the glycosylation patterns of transferrin do not differ according to the activity index of ulcerative colitis. The microheterogeneity patterns of AGP and ACT are similar in ulcerative colitis patients and healthy subjects.

[Evaluation of chosen parameters of acute-phase reaction in children during pseudocroup according to their age]. / Analiza wybranych parametrów reakcji ostrej fazy w przebiegu podglosniowego zapalenia krtani w zaleznosci od wieku dziecka.

INTRODUCTION: Acute subglottic laryngitis (pseudocroup) usually occurs in infants and small children between 1 and 3 years of age. Due to the viral etiology there are autumn-winter and winter-spring peaks of frequency of this disease observed. Acute-phase proteins are a group of proteins whose concentration in the serum changes following variety of injuries such as bacterial, viral or parasitic infection. These changes are one of the features of an early, non-specific and highly complex reaction of the organism called acute-phase response. The purpose of this reaction is to restore homeostasis. Almost all acute-phase proteins are glycoproteins and changes in their microheterogeneity (glycosylation profile: structure of side suger chains) were also reported during different inflammatory conditions. MATERIAL AND METHODS: 51 children admitted to the Pediatric ENT Dept in Poznan because of an incident of pseudocroup were divided into 3 groups according to their age: I (0-3 years of age), II (between 3 and 5 years old) and III (over 5 years old). In all children levels of selected acute-phase proteins such as a1-antitrypsin [AT], al-antichymotrypsin [ACT], al-acid glycoprotein [AGP], ceruloplasmin [Cp], transferrin [Tf] and haptoglobin [Hp] were measured in three time points: at the beginning of the disease, after treatment and 3 weeks later during control examination. In all sera samples also glycosylation profile of AGP, ACT and Tf was performed. RESULTS: Analysis of AGP glycosylation profile revealed the highest levels of microheterogeneity variants: W2 and W3 in the group of children over 5 years old. Also AGP-RC was significantly increased in this group. The Tf variant T4 reached the highest level in children between 3 and 5 years of age. In all age groups increased level of Hp was observed during treatment and decreased 3 weeks later during control examination. CONCLUSIONS: Acute-phase reaction is the most intensive in the youngest children. Analysis of glycosylation profile revealed acute inflammatory process during episode of pseudocroup in the oldest children (over 5 years old) and chronic inflammation in group of the youngest children.

Estimation of hurdle clearance parameters using a monocular human motion tracking method.

This paper presents a method of monocular human motion tracking for estimation of hurdle clearance kinematic parameters. The analysis involved 10 image sequences of five hurdlers at various training levels. Recording of the sequences was carried out under simulated starting conditions of a 110 m hurdle race. The parameters were estimated using the particle swarm optimization algorithm and they are based on analysis of the images recorded with a 100 Hz camera. The proposed method does not involve using any special clothes, markers, inertial sensors, etc. As the quality criteria, the mean absolute error and mean relative error were used. The level of computed errors justifies the use of this method to estimate hurdle clearance parameters.

Seasonal rhythms of "acute phase proteins" in humans.

"Acute phase proteins" comprise a group of proteins whose concentrations increase or decrease by at least 25% after a damaging stimulus (burn, trauma, tissue damage, etc.) or during inflammation. We investigated the seasonal variation in the concentrations of several acute phase proteins--alpha1-antichymotrypsin (ACT), alpha1-acid glycoprotein (AGP), transferrin (Tf), alpha2-macroglobulin (alpha2-M), ceruloplasmin (Cp), antitrypsin (AT), and haptoglobin (Hp). Blood samples were collected from 15 healthy volunteers, who were subjected to the seasonal changes in illumination, were drawn at 08:00 h every 3 months (August, November, January/February, March/April, June/July). With the exception of Hp, all acute phase proteins showed an annual rhythm (ANOVA; p < 0.01). Lowest concentrations occurred in the winter months (November through February), with the exception of Tf, which was oppositely phased.

Cytokines and heart rate variability in patients with chronic heart failure.

INTRODUCTION: Heart rate variability (HRV) analysis is a non-invasive method of assessment of the autonomic nervous system's effects on heart function. In chronic heart failure (CHF), decreased HRV correlates with the progression of the disease. It is also known that in CHF increased levels of proinflammatory cytokines are present. Because these molecules are believed to influence the nervous system at both the central and peripheral levels, their potential role in HRV reduction in the course of CHF has been proposed. AIM: The study was designed to verify potential relations between cytokines and HRV parameters in CHF patients. The concept of the study was driven by the recognition of controversies in this field and the paucity of published reports. METHODS: Forty-four patients with CHF and stable NYHA class I-IV symptoms and 15 healthy controls were enrolled in the study. Time-domain HRV analysis was performed based on of 24-hour Holter ECG monitoring. Plasma concentrations of soluble TNFalpha receptors sTNF-RI and sTNF-RII and interleukin 6 (IL-6) were measured using commercially available ELISA kits (Quantikine, RD Systems). RESULTS: In patients with CHF, HRV indices included in the analysis were significantly decreased, and the levels of cytokines increased in comparison with the control group. In the whole study population, both in the CHF patients and the control group, significant negative correlations were observed between sTNF-RI level and long-term HRV indices such as SDNN (r=-0.44; p=0.0006), SDANN (r=-0.44; p=0.0005) and short-time index SDNNI (r=-0.37; p=0.004). Similar negative correlations were found between sTNF-RII level and SDNN (r=-0.35; p=0.007), SDANN (r=-0.34; p=0.01), and SDNNI (r=-0.31; p=0.02), as well as between IL-6 level and SDNN (r=-0.41; p=0.001), SDANN (r=-0.44; p=0.0005) and SDNNI (r=-0.34; p=0.009). CONCLUSIONS: Significant negative correlations between TNF-alpha soluble receptors sTNF-RI, sTNF-RII and IL-6 levels and time-domain HRV parameters were observed in the study. Because the results of investigations conducted so far do not elucidate the cause-effect relationship, further studies are needed to clarify the mechanisms of HRV depression in CHF and the role of cytokines in this severe clinical condition.

[Some acute phase proteins in children suffering from recurrent laryngeal papillomatosis]. / Wybrane bialka ostrej fazy u dzieci z nawracajacymi brodawczakami krtani.

INTRODUCTION: The aim of the study was to compare the character of inflammatory reaction in the groups of sick children, asymptomatic carriers of HPV and healthy children by quantitative and qualitative study of chosen acute phase proteins like CRP, AT, ACT. Profile of glycosylation of ACT was analysed. MATERIAL AND METHODS: The study group was 21 children treated in ENT Department of Pediatric Institute of the Karol Marcinkowski University for laryngeal papillomatosis (infected by HPV 6/11 in 100%) and the group of 22 selected asymptomatic carriers of HPV 6/11. The control group were 22 children in which the presence of HPV 6/11 DNA was excluded using PCR technique. Serum concentration of the APP was measured using immunoelectrophoresis technique according to Laurell. Qualitative study of the APP based on analysis of AGP and ACT microheterogeneity using crossed immuno-affinoelectrophoresis on agarose gel according to Bog-Hansen in Mackiewicz modification was carried out. RESULTS: The results were analysed with regard to: 1. the age of the first incident (ten children in whom the first symptoms occurred up to the second year of life, and eleven in whom the first symptoms were detected later; 2. severity of the disease course (seven children in whom four or more microsurgeries were performed within a year, and fourteen children in whom fever than four interventions were carried out). The decrease of ACT, AT levels in serum was observed. It was found that the ACT glycosylation profile is close to normal in sick children, what suggests the absence of inflammatory reaction stimulation. CONCLUSIONS: The results suggest that clinical infection of HPV is likely to be connected with discoordination of immunological reaction mechanism.

Predictive Modeling in Race Walking.

This paper presents the use of linear and nonlinear multivariable models as tools to support training process of race walkers. These models are calculated using data collected from race walkers' training events and they are used to predict the result over a 3 km race based on training loads. The material consists of 122 training plans for 21 athletes. In order to choose the best model leave-one-out cross-validation method is used. The main contribution of the paper is to propose the nonlinear modifications for linear models in order to achieve smaller prediction error. It is shown that the best model is a modified LASSO regression with quadratic terms in the nonlinear part. This model has the smallest prediction error and simplified structure by eliminating some of the predictors.

Spectral properties of phthalocyanines incorporated into resting and stimulated human peripheral blood cells.

Human peripheral blood cells stimulated by phytohemagglutinin (which serve as a model of cancerous cells) and resting cells were incubated in dimethyl sulfoxide solutions of various phthalocyanines. In order to diminish the influence of atmospheric oxygen the cells were embedded in a polymer (polyvinyl alcohol) film. Fluorescence spectra of the samples were measured over two regions of excitation wavelengths: at 405 nm (predominant absorption of the cell material) and in the regions of strong absorption of phthalocyanines (at about 605 nm and 337 nm). The intrinsic emission of cell material became changed as a result both of cells' stimulation and of incubation of cells in dye solution. In most cases the stimulated cells when stained by dye exhibited higher long wavelength fluorescence intensity than resting cells. This suggests higher efficiency of dye incorporation into cancerous cells than into healthy cells. The absorption spectra of samples were also measured. The spectra of various phthalocyanines in incubation solvent, in polymer and in the cells embedded in polymer, were compared. The comparison of properties of the cells stimulated for different time periods enabled to establish the conditions of stimulation creating a population of cells incorporating a large number of sensitizing molecules.

Preliminary studies of phthalocyanine sensitizers incorporated into human leukemia cells from two cell-lines.

Three phthalocyanine dyes-sensitizers were incorporated into two types of human T leukemia cells from two cell-lines: CCRF and MOLT 4. The efficiency of the dye incorporation into cells and photochemical properties of stained cells were investigated using fluorescence spectroscopy. The dyes exhibited different properties in each of the two cell-lines. Small differences in cell membrane properties have a strong influence on the efficiency of dye incorporation and on the course of photodynamic reaction. It is suggested that, for a given patient, an optimal dye-sensitizer should be established before photodynamic treatment.

[The interaction of stilbazolium merocyanines with hyperproliferative laryngeal papilloma cells--preliminary study]. / Oddzialywanie merocyjanin stilbazolowych z hiperproliferujacymi komórkami nablonkowymi brodawczaków krtani typu dzieciecego--badania wstepne.

Recently increasing interest focused in possible clinical application on photodynamic therapy was observed. Many scientists are looking for new chemical compounds effective in therapy and giving no side effects. Stilbazolium merocyanines belong to lipophilic dyes, binding to cell membranes. The aim of this study was to estimate the usefulness of the selected stilbazolium merocyanines to treatment on human recurrent respiratory papillomatosis. A patients group consisted of seven children, ages 10 months to 18 years, with moderate to severe recurrent disease. The patients were treated surgically. Tissue samples were analyzed for presence of Human papillomavirus (HPV). The incorporation of the dye into papillomas cells membranes was measured by flow cytometry. As a measure of fluorescence intensitivity the value "mean channel" was used. The hyperplastic tissue showed the highest fluorescence intensity than normal epithelium. Obtained results showed that continue to this preliminary studies is necessary.

Toxicity of cylindrospermopsin in human lymphocytes: proliferation, viability and cell cycle studies.

The global expansion of cylindrospermopsin (CYN) producing cyanobacteria in surface freshwater increases the risk of human exposure and poisoning. Following ingestion, CYN is transported with blood in general circulation to the liver and kidneys, and can potentially interact with immune system cells. In the present study, we investigated whether CYN (0.01-1.0 µg ml(-1)) can alter the function of human peripheral blood lymphocytes isolated from healthy donors. It was found that CYN demonstrates significant antiproliferative activity in lymphocytes during different phases of their activation. The most remarkable effects (decrease by>90%) were observed in lymphocytes exposed to 1 µg ml(-1) CYN at the beginning of activation. Further analyses revealed a cell-cycle arrest at G0/G1 and prolonged S phase in lymphocytes undergoing activation and significant apoptosis inducement in activated cells. Reduced abilities to fight pathogenic microorganisms or malignant cells should be taken into consideration in CYN exposure and risk assessments.