Leptin receptor in childhood acute leukemias.

Ob-R receptor is encoded by db gene and belongs to class I cytokine receptors family. Its expression was observed in hematopoietic CD34+ stem cells, erythropoietic, myeloid and lymphoblastic lineages cell lines and in human leukemic blast cells in lymphomas, acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), and chronic myeloid leukemia (CML). The studies on human bone marrow cells show that JAK/STAT pathway plays a substantial role in signal transduction in young bone marrow cells. The aim of the study was to examine the relationship between leptin receptor expression and the proliferation of neoplastic hematopoietic cells in bone marrow. The study was performed in a total of 57 children of both sexes aged 3 months to 16 years. A group of 46 patients with acute leukemia involved 25 children with ALLB, 11 children with ALLT and 10 children with ANNL. The control group consisted of 11 non-obese children with non-malignant hematological disturbances. The tests were performed on bone marrow samples. The assessments of membrane expression of Ob-R and the antigens determining the phenotype of bone marrow cells were performed using a flow cytometry method. In acute lymphoblastic leukemia, a significant decrease of Ob-R expression on leukemic blasts was observed in comparison with respective populations of normal bone marrow cells. Also in progenitor cells populations a significant decrease of CD34+Ob-R+w ALLT and ALLB was observed in comparison with the cells from normal bone marrow. No statistically significant differences in the percentage of Ob-R+ cells in ANNL bone marrow and in control bone marrow were observed.

Implementation and experimental results of 4D tumor tracking using robotic couch.

PURPOSE: This study presents the implementation and experimental results of a novel technique for 4D tumor tracking using a commercially available and commonly used treatment couch and evaluates the tumor tracking accuracy in clinical settings. METHODS: Commercially available couch is capable of positioning the patient accurately; however, currently there is no provision for compensating physiological movement using the treatment couch in real-time. In this paper, a real-time couch tracking control technique is presented together with experimental results in tumor motion compensation in four dimensions (superior-inferior, lateral, anterior-posterior, and time). To implement real-time couch motion for tracking, a novel control system for the treatment couch was developed. The primary functional requirements for this novel technique were: (a) the treatment couch should maintain all previous∕normal features for patient setup and positioning, (b) the new control system should be used as a parallel system when tumor tracking would be deployed, and (c) tracking could be performed in a single direction and∕or concurrently in all three directions of the couch motion (longitudinal, lateral, and vertical). To the authors' best knowledge, the implementation of such technique to a regular treatment couch for tumor tracking has not been reported so far. To evaluate the performance of the tracking couch, we investigated the mechanical characteristics of the system such as system positioning resolution, repeatability, accuracy, and tracking performance. Performance of the tracking system was evaluated using dosimetric test as an endpoint. To investigate the accuracy of real-time tracking in the clinical setting, the existing clinical treatment couch was replaced with our experimental couch and the linear accelerator was used to deliver 3D conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) treatment plans with and without tracking. The results of radiation dose distribution from these two sets of experiments were compared and presented here. RESULTS: The mechanical accuracies were 0.12, 0.14, and 0.18 mm in X, Y, and Z directions. The repeatability of the desired motion was within ±0.2 mm. The differences of central axis dose between the 3D-CRT stationary plan and two tracking plans with different motion trajectories were 0.21% and 1.19%. The absolute dose differences of both 3D tracking plans comparing to the stationary plan were 1.09% and 1.20%. Comparing the stationary IMRT plan with the tracking IMRT plan, it was observed that the central axis dose difference was -0.87% and the absolute difference of both IMRT plans was 0.55%. CONCLUSIONS: The experimental results revealed that the treatment couch could be successfully used for real-time tumor tracking with a high level of accuracy. It was demonstrated that 4D tumor tracking was feasible using existing couch with implementation of appropriate tracking methodology and with modifications in the control system.

Expression of constitutively active Raf-1 in the mitochondria restores antiapoptotic and leukemogenic potential of a transformation-deficient BCR/ABL mutant.

The oncogenic BCR/ABL protein protects hematopoietic cells from apoptosis induced by growth factor deprivation, but the mechanisms are only partially understood. A BCR/ABL mutant lacking amino acids 176-426 in the BCR domain (p185DeltaBCR) failed to protect interleukin 3-deprived 32Dcl3 myeloid precursor cells from apoptosis, although it possessed tyrosine kinase activity and was capable of activating the Ras-Raf-MAP kinase pathway. Compared to p185 wild-type transfectants, p185DeltaBCR-transfected cells showed markedly reduced levels of Bcl-2 and expressed the hypophosphorylated, proapoptotic form of BAD. Bcl-2 expression in the mitochondrial fraction of p185DeltaBCR cells was also markedly diminished and mitochondrial RAF was undetectable. In p185DeltaBCR cells transfected with a mitochondria-targeted, constitutively active RAF (M-Raf) BAD was expressed in the hyperphosphorylated form and released from the mitochondria into the cytosol. p185DeltaBCR/M-Raf-transfected cells were completely resistant to apoptosis induced by growth factor deprivation in vitro. Moreover, constitutive expression of dominant-negative M-Raf (K375W) enhanced the susceptibility of 32Dcl3 cells expressing wild-type BCR/ABL to apoptosis. In severe combined immunodeficiency (SCID) mice, p185DeltaBCR/M-Raf double transfectants were leukemogenic, whereas cells expressing only p185DeltaBCR showed no leukemogenic potential. Together, these data support the existence of a BCR/ABL-dependent pathway that leads to expression of an active RAF in the mitochondria and promotes antiapoptotic and leukemia-inducing effects of BCR/ABL.

Signal transducer and activator of transcription (STAT)5 activation by BCR/ABL is dependent on intact Src homology (SH)3 and SH2 domains of BCR/ABL and is required for leukemogenesis.

Signal transducer and activator of transcription (STAT)5 is constitutively activated in BCR/ ABL-expressing cells, but the mechanisms and functional consequences of such activation are unknown. We show here that BCR/ABL induces phosphorylation and activation of STAT5 by a mechanism that requires the BCR/ABL Src homology (SH)2 domain and the proline-rich binding site of the SH3 domain. Upon expression in 32Dcl3 growth factor-dependent myeloid precursor cells, STAT5 activation-deficient BCR/ABL SH3+SH2 domain mutants functioned as tyrosine kinase and activated Ras, but failed to protect from apoptosis induced by withdrawal of interleukin 3 and/or serum and did not induce leukemia in severe combined immunodeficiency mice. In complementation assays, expression of a dominant-active STAT5B mutant (STAT5B-DAM), but not wild-type STAT5B (STAT5B-WT), in 32Dcl3 cells transfected with STAT5 activation-deficient BCR/ABL SH3+SH2 mutants restored protection from apoptosis, stimulated growth factor-independent cell cycle progression, and rescued the leukemogenic potential in mice. Moreover, expression of a dominant-negative STAT5B mutant (STAT5B-DNM) in 32Dcl3 cells transfected with wild-type BCR/ABL inhibited apoptosis resistance, growth factor-independent proliferation, and the leukemogenic potential of these cells. In retrovirally infected mouse bone marrow cells, expression of STAT5B-DNM inhibited BCR/ABL-dependent transformation. Moreover, STAT5B-DAM, but not STAT5B-WT, markedly enhanced the ability of STAT5 activation-defective BCR/ABL SH3+SH2 mutants to induce growth factor-independent colony formation of primary mouse bone marrow progenitor cells. However, STAT5B-DAM did not rescue the growth factor-independent colony formation of kinase-deficient K1172R BCR/ABL or the triple mutant Y177F+R522L+ Y793F BCR/ABL, both of which also fail to activate STAT5. Together, these data demonstrate that STAT5 activation by BCR/ABL is dependent on signaling from more than one domain and document the important role of STAT5-regulated pathways in BCR/ABL leukemogenesis.

Decreased CD4+CD152+ T cell subset and its correlation with the level of antithyroid antibodies in children with chronic autoimmune thyroiditis.

OBJECTIVE: Cytotoxic T lymphocyte antigen-4 (CTLA-4) is one of the basic antigens involved in immune responses regulation associated with autoimmune thyroid diseases. The aim of the study was to evaluate whether the surface expression of CTLA-4(CD152) on T cells is correlated with laboratory autoimmune markers in children with Hashimoto's disease. MATERIAL AND METHODS: Blood samples were obtained from 45 children with Hashimoto's thyroiditis of the mean age 14.8 ±2.35 years, and from 55 healthy age-matched children, free of allergic, immune and hematological disorders, and with a normal thyroid function. The anti-thyroid antibodies were measured with Microparticle Enzyme Immunoassay (AxSYM Anti-Tg, AxSYM Anti-TPO). The T cell phenotype was evaluated flow cytometery, with the use of monoclonal antibodies combination: CD4- FITC/ CD28 -PC5/ CD152 -PE and CD8 -FITC/ CD28 -PC5/ CD152 -PE. - RESULTS: The percentage of T cells with CD152 expression was significantly decreased in children with Hashimoto's thyroiditis compared with healthy controls (P<0.001). A significant negative correlation was found between the level of anti-thyroglobulin antibodies and the percentage of CD4+CD152+ T cells (r = -0.34; P<0.05). Anti-thyroperoxidase antibodies did not correlate with CD152 expression. CONCLUSIONS: In children with Hashimoto's thyroiditis, the number of CD4+CD152+ T cells is decreased and negatively correlates with the level of anti-thyroglobulin antibodies.

Sublingual immunotherapy in asthma does not influence lymphocyte sensitivity to Fas stimulation.

BACKGROUND: The resistance of T lymphocytes to Fas-mediated apoptosis is an important feature of atopic asthma. The only effective causative treatment of atopic diseases is immunotherapy. Clinical efficacy of sublingual immunotherapy (SLIT) has been already proven, but there is still limited number of studies on its influence on lymphocytes function. OBJECTIVES: The aim of the study was to evaluate whether SLIT could restore the sensitivity of asthmatic T cells to undergo Fas-mediated apoptosis. MATERIAL AND METHODS: Peripheral blood was collected from 12 patients aged 8 ±2 years suffering from atopic asthma and undergoing sublingual specific immunotherapy. To evaluate sensitivity to Fas-mediated apoptosis, the blood was transmitted to sterile tubes and mixed with purified monoclonal antibody anti-CD95. After incubation, leukocytes were stained with Annexin V, propidium iodide, and monoclonal antibody against CD2 conjugated with phycoerythrin-cyanin 5.1, and then analyzed with flow cytometry. The procedure was repeated for each patient after 12 months of SLIT. - RESULTS: Stimulation with anti-CD95 of T lymphocytes from patients with atopic asthma before treatment increased the number of early apoptotic cells (from 19.5 ±16.7% before stimulation to 26.6 ±16.7% Annexin V positive cells after stimulation). After one year of SLIT anti-CD95 still caused an increase of the early apoptotic cells ratio in the lymphocyte population (from 12.4 ±7.4% before stimulation to 24.7 ±15.4% Annexin V positive T cells after CD95 stimulation). Although an increasing trend could be observed, differences between the analyzed groups were not statistically significant. CONCLUSIONS: A year of SLIT does not change the sensitivity of T lymphocytes from peripheral blood of children suffering from atopic asthma to Fas-mediated apoptosis.

Leptin receptors.

Leptin or obesity receptor (Ob-R) is a member of class I cytokine receptor family. Ob-R, expressed in six isoforms, is the product of alternative RNA splicing of db gene. According to its structural differences, the receptor's isoforms are divided into three classes: long, short, and secretory isoforms. A long, fully active isoform of Ob-Rb is expressed mainly in the hypothalamus, where it takes part in energy homeostasis and in the regulation of secretory organs' activity. Ob-Rb is also present on all types of immune cells, involved in innate and adaptive immunity. Short leptin isoforms (Ob-Ra, Ob-Rc, Ob-Rd, and Ob-Re) that contain box 1 motif are able to bind JAK kinases (Janus kinases) as well as to activate some other signal transduction cascades. A soluble isoform (Ob-Re) can regulate serum leptin concentration and serve as a carrier protein delivering the hormone to its membrane receptors and is able to transduce the signal into the cell. JAK/STAT pathway plays the major role in leptin signal transduction through membrane receptors. Among all Ob-R isoforms, only full-length isoform (Ob-Rb) is able to fully transduce activation signal into the cell.

No association of LEPR Gln223Arg polymorphism with leptin, obesity or metabolic disturbances in children.

OBJECTIVE: The aim of the study was to investigate whether the Gln223Arg in the leptin receptor may influence body weight, leptin concentration, and metabolic parameters in children. MATERIALS AND METHODS: The examined group included 101 obese children (58 girls and 43 boys) with BMI 31.41 +/-5.03 kg/m(2) (BMI > or = 2 SDS) and the control group consisted of 41 children with BMI 20.0 +/-0.80 kg/m2 (BMI <1.0 SDS). Polymorphism identification was performed in total genomic DNA using PCR-RFLP method. RESULTS: The distribution of genotypes LEPR was the following: in the obese group: AA - 20.8%, AG- 55.4%, GG-23.8 %; in the control group AA-31.7%, AG- 53.65%, GG-14.65%. Comparative analyses between AA homozygous children and carriers of G alleles did not confirm any relation between the analyzed polymorphism and BMI, leptin concentrations, and metabolic disturbances in children with obesity. CONCLUSION: In children with obesity we did not observe association of the LEPR Gln223Arg gene polymorphism with obesity, leptin, insulin resistance, and metabolic abnormalities.

Association between metabolic disturbances and G-174C polymorphism of interleukin-6 gene in obese children.

OBJECTIVE: The aim of the study was to investigate whether the G-174C polymorphism of the IL-6 gene is related to obesity and the incidence of the metabolic syndrome (MetS) according to IDF definition in children. MATERIALS AND METHODS: The examined group included 124 obese children with BMI > or = 2 SDS, and the control group consisted of 56 non-obese children with BMI <1.0 SDS. Polymorphism identification was performed in total genomic DNA using PCR-RFLP method. RESULTS: In the obese children, carriers of C allele in homozygotic and heterozygotic genotypes were more frequent than in the control group. The carriers of C alleles presented with lower thickness of subcutaneous tissue and higher concentrations of HDL-C than the wild type. The incidence of MetS was 33% of the group of obese children. Analysis of the presence of MetS factors showed that there is more frequent MetS in the group with the wild homozygous genotype type. CONCLUSION: Polymorphism 174G>C in the IL-6 gene does not seem to be associated with obesity and with the incidence of MetS in children.

Influence of proinflammatory cytokine gene polymorphism on childhood obesity.

BACKGROUND: Obesity development is a complex process which can be influenced by genetic predisposition modified by environmental factors. Nowadays, the problem of overweight and obesity, including related complications, occurs in increasingly younger children. Thus, there is a need for new genetic markers of increased risk of excessive body mass. OBJECTIVE: The aim of the present study was to examine the relation between polymorphisms located in promoter regions of IL-1beta, IL-6, and TNF-alpha genes and obesity development in children. Fifty obese and 55 normal weighing children were enrolled into the study. Genetic examination was performed using PCR-RFLP technique. RESULTS: We found a relation between G174C polymorphism in IL-6 gene and G308A in TNF-alpha gene with the occurrence of obesity. Allele A in G308A was more frequent in the obese group than in the control one (P=0.04). The presence of allele C in promoter region of IL-6 gene was more frequent in obese children and connected with a statistically significant increase in the sum of 10 skin fold thickness measurements (P=0.03). CONCLUSIONS: The polymorphism C3954T in IL-1beta gene showed no such relation. The examined polymorphisms of proinflammatory cytokines play a role in the regulation of body mass through their influence on metabolism and energetic homeostasis.

Oncogenic tyrosine kinase NPM/ALK induces activation of the MEK/ERK signaling pathway independently of c-Raf.

The mechanisms of cell transformation mediated by the highly oncogenic, chimeric NPM/ALK tyrosine kinase remain only partially understood. Here we report that cell lines and native tissues derived from the NPM/ALK-expressing T-cell lymphoma (ALK+ TCL) display phosphorylation of the extracellular signal-regulated protein kinase (ERK) 1/2 complex. Transfection of BaF3 cells with NPM/ALK induces phosphorylation of EKR1/2 and of its direct activator mitogen-induced extracellular kinase (MEK) 1/2. Depletion of NPM/ALK by small interfering RNA (siRNA) or its inhibition by WHI-154 abrogates the MEK1/2 and ERK1/2 phosphorylation. The NPM/ALK-induced MEK/ERK activation is independent of c-Raf as evidenced by the lack of MEK1/2 and ERK1/2 phosphorylation upon c-Raf inactivation by two different inhibitors, RI and ZM336372, and by its siRNA-mediated depletion. In contrast, ERK1/2 activation is strictly MEK1/2 dependent as shown by suppression of the ERK1/2 phosphorylation by the MEK1/2 inhibitor U0126. The U0126-mediated inhibition of ERK1/2 activation impaired proliferation and viability of the ALK+ TCL cells and expression of antiapoptotic factor Bcl-xL and cell cycle-promoting CDK4 and phospho-RB. Finally, siRNA-mediated depletion of both ERK1 and ERK2 inhibited cell proliferation, whereas depletion of ERK 1 (but not ERK2) markedly increased cell apoptosis. These findings identify MEK/ERK as a new signaling pathway activated by NPM/ALK and indicate that the pathway represents a novel therapeutic target in the ALK-induced malignancies.

Oncogenic tyrosine kinase NPM/ALK induces activation of the rapamycin-sensitive mTOR signaling pathway.

The mechanisms of cell transformation mediated by the nucleophosmin (NPM)/anaplastic lymphoma kinase (ALK) tyrosine kinase are only partially understood. Here, we report that cell lines and native tissues derived from the NPM/ALK-expressing T-cell lymphoma display persistent activation of mammalian target of rapamycin (mTOR) as determined by phosphorylation of mTOR targets S6rp and 4E-binding protein 1 (4E-BP1). The mTOR activation is serum growth factor-independent but nutrient-dependent. It is also dependent on the expression and enzymatic activity of NPM/ALK as demonstrated by cell transfection with wild-type and functionally deficient NPM/ALK, small interfering RNA (siRNA)-mediated NPM/ALK depletion and kinase activity suppression using the inhibitor WHI-P154. The NPM/ALK-induced mTOR activation is transduced through the mitogen-induced extracellular kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway and, to a much lesser degree, through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway. Accordingly, whereas the low-dose PI3K inhibitor wortmannin and Akt inhibitor III profoundly inhibited Akt phosphorylation, they had a very modest effect on S6rp and 4E-BP1 phosphorylation. In turn, MEK inhibitors U0126 and PD98059 and siRNA-mediated depletion of either ERK1 or ERK2 inhibited S6rp phosphorylation much more effectively. Finally, the mTOR inhibitor rapamycin markedly decreased proliferation and increased the apoptotic rate of ALK+TCL cells. These findings identify mTOR as a novel key target of NPM/ALK and suggest that mTOR inhibitors may prove effective in therapy of ALK-induced malignancies.

EBV PCR in the diagnosis and monitoring of posttransplant lymphoproliferative disorder: results of a two-arm prospective trial.

While EBV PCR is used in the management of PTLD, the optimal primer set, relative importance of intracellular versus free plasma EBV, and the baseline profile in an organ transplant population remains unclear. We performed a prospective 2-arm trial utilizing an EBV PCR panel measuring LMP-1, EBER-1 and EBNA-1 in both free plasma as well as intracellular whole blood. Control Arm A consisted of 31 lung transplant patients and Arm B consisted of 35 transplant patients being evaluated for possible PTLD. In Arm A, 1/31 (3%) patients developed a transient plasma EBV load. Thirteen of 31 (42%) had detectable intracellular EBV. In Arm B, 17 (49%) patients were diagnosed with PTLD. Thirteen (76%) had EBV-positive PTLD with 12/13 (92%) having detectable EBV by PCR. The EBV PCR panel had a high sensitivity (92%), specificity (72%), positive predictive value (PPV) (71%) and negative predictive value (NPV) (93%) for diagnosing EBV-positive PTLD and followed patients' clinical course well (p < 0.001). Comparing the individual PCR assays, plasma EBNA PCR was superior with high sensitivity (77%), specificity (100%), PPV (100%) and NPV (86%). We conclude that EBV PCR is a useful test for managing PTLD patients. While plasma EBNA PCR is the best single assay for diagnosing and monitoring PTLD, the complete PCR panel is superior for ruling out its presence.

Increased serum fractalkine in systemic sclerosis. Down-regulation by prostaglandin E1.

OBJECTIVES: To evaluate serum levels of fractalkine (FKN), a mediator of leukocyte transmigration, C-reactive protein (CRP) and expression of integrins CD11a and CD49d on peripheral blood lymphocytes in systemic sclerosis (SSc) and to investigate whether they are modulated by intravenous prostaglandin E1 (PGE1). METHODS: Serum levels of fractalkine and C-reactive protein and expression of CD11a and CD49d on peripheral blood lymphocytes were assessed in 50 SSc patients and in 18 healthy controls. In 25 SSc patients studied parameters were evaluated also after 3 consecutive daily PGE1 infusions (20 microg-40 microg-60 microg) and after 4 weeks. RESULTS: In SSc fractalkine basal level was significantly higher than in controls (9.04+/-1.79 ng/ml vs. 1.17+/-0.1 ng/ml; p<0.0001) and decreased significantly after PGE1 (5.16+/-1.27 ng/ml, p<0.05). After four weeks fractalkine level was still significantly lower than baseline 7.70+/-2.19 ng/ml (p<0.05). Basal percentage of CD11a (+) nor CD49d (+) lymphocytes in SSc (82.38+/-1.60%, 70.74+/-1.68%, respectively) did not differ from controls (85.73+/-2.04%, 75.62+/-2.48%; respectively, p>0.05). PGE1 treatment resulted in decrease of both CD11a (+) (67.72+/-3.34%, p<0.0001) and CD49d (+) lymphocytes (65.32+/-1.62%, p<0.0001). After 4 weeks the percentage of CD11a (+) and CD49d (+) lymphocytes remained significantly lower than at baseline (77.80+/-2.47% and 65.32+/-1.62%, respectively, both p<0.001). In SSc CRP basal level was significantly higher than in controls (4.70+/-2.01 mg/dl vs. 1.40+/-1.79 mg/dl, p<0.005) and reduced significantly after PGE1 (3.39+/-2.06 mg/dl, p<0.05). After 4 weeks, CRP level (4.38+/-2.19 ng/ml) was significantly lower than baseline (p<0.05). CONCLUSION: Fractalkine may play an important role in the pathogenesis of vascular dysfunction in systemic sclerosis. Prostaglandin E1 down-regulates serum fractalkine level, as well as CD11a and CD49d expression on peripheral blood lymphocytes, which suggests additional mechanisms in which this vasodilatatory agent exerts its efficacy in systemic sclerosis.

Expression of constitutively nuclear cyclin D1 in murine lymphocytes induces B-cell lymphoma.

Mantle cell lymphoma (MCL) is a B-cell lymphoma characterized by overexpression of cyclin D1 due to the t(11;14) chromosomal translocation. While expression of cyclin D1 correlates with MCL development, expression of wild-type (WT) cyclin D1 transgene in murine lymphocytes is unable to drive B-cell lymphoma. As cyclin D1 mutants that are refractory to nuclear export display heighten oncogenicity in vitro compared with WT D1, we generated mice expressing FLAG-D1/T286A, a constitutively nuclear mutant, under the control of the immunoglobulin enhancer, Emu. D1/T286A transgenic mice universally develop a mature B-cell lymphoma. Expression of D1/T286A in B lymphocytes results in S phase entry in resting lymphocytes and increased apoptosis in spleens of young premalignant mice. Lymphoma onset correlates with perturbations in p53/MDM2/p19Arf expression and with BcL-2 overexpression suggesting that alterations in one or both of these pathways may contribute to lymphoma development. Our results describe a cyclin D1-driven model of B-cell lymphomagenesis and provide evidence that nuclear-retention of cyclin D1 is oncogenic in vivo.

The influence of low-power helium-neon laser irradiation on function of selected peripheral blood cells.

The effects of low-level laser light irradiation are debatable and the mechanisms of its action are still unclear. This study was conducted to test the effects of low-level laser irradiation on human blood cells: erythrocytes, granulocytes, and lymphocytes. Whole blood obtained by phlebotomy was irradiated at 632.8 nm by using energy fluences 0.6 J/cm2. An analysis of blood gases revealed an increase in PO2 and SaO2 (P<0.001) in irradiated blood. No shifts in PCO2 and pH were recorded. Spontaneous synthesis of DNA in T and B blood lymphocytes decreased significantly after laser irradiation (P<0.02 and P<0.04, respectively). Phytohemagglutinin (PHA)-induced proliferation of T cells and SAC proliferation of B cells, expressed as a stimulation index, were statistically higher in the samples of irradiated than in non-irradiated blood (P<0.01). Chemiluminescence of fMLP-stimulated granulocytes from irradiated blood increased in comparison with non-irradiated samples (P<0.001). No changes of spontaneous and stimulated chemiluminescence kinetics in irradiated samples were observed. These results reveal the influence of photodynamic reactions on the ability of blood to transport oxygen and on immunomodulatory effects on leukocytes.

Frequency of distribution of leptin receptor gene polymorphism in obstructive sleep apnea patients.

Leptin is an adipocyte-derived hormone regulating energy homeostasis and body weight. Leptin concentration is increased in patients with the obstructive sleep apnea syndrome (OSAS). Leptin receptor (LEPR) is a single transmembrane protein belonging to the superfamily of cytokine receptors related by a structure to the hemopoietin receptor family. The aim of the present study was to evaluate the frequency of distribution of leptin receptor gene polymorphism GLN223ARG in OSAS patients compared with healthy controls. The examined group included 179 subjects: 102 OSAS patients (74 men and 28 women) and 77 non-apneic controls (39 men and 38 women). Genomic DNA was isolated with the use of a column method and genotyping of DNA sequence variation was carried out by restriction enzyme analysis of PCR-amplified DNA. The results revealed a significant correlation between the polymorphism of LEPR and OSAS. Carriers of Arg allele in homozygotic genotype Arg/Arg and heterozygotic genotype Gln/Arg were more often obese and developed OSAS than the group of carriers of homozygotic Gln/Gln genotype. This tendency was observed in the whole examined population and in the group of obese women. We also found the highest levels of total cholesterol, LDL, HDL, and triglycerides in the group of homozygotic Arg/Arg genotype carriers, lower in heterozygotic Gln/Arg genotype carriers, and the lowest in the group of persons carring homozygotic Gln/Gln genotype. The presence of Arg allel seems linked to a higher risk of obesity and higher lipid levels in OSAS patients. OSAS may have a strong genetic basis due to the effects from a variety of genes including those for leptin receptor.

Heterogeneity of antibody response to myobacterial antigens in different clinical manifestations of pulmonary tuberculosis.

Different clinical outcomes of tuberculosis can be related to the balance between cell-mediated and humoral immunity. In this prospective study we examined the humoral immune responses to recombinant and native mycobacterial antigens in relation to clinical presentations of pulmonary TB. Two hundred and fifteen serum samples were examined including: non-cavitary (n=120), cavitary (n=65), caseous pneumonia (n=12), and disseminated TB (n=18). ELISA tests detecting IgG, IgA, and IgM against antigens: 38 kDa and 16 kDa, 38 kDa and lipoarabinomannan (LAM) were used. Univariate and multivariate logistic regression analyses were carried out to find the association between the antibody level and demographic or clinical characteristics. The relationships among specific antibody profiles and the phase of the disease in relation to demographic (age and sex) and clinico-radiological factors were investigated by measuring serum antibody levels (IgG, IgA, and IgM) to 38 kDa and 16 kDa recombinant M. tuberculosis antigens and to LAM - native mycobacterial antigen. The results show that the radiological extent of the disease is the strongest factor associated with IgG antibody production. Patients with more extensive pulmonary TB showed higher titers of IgG antibody to M. tuberculosis antigens (P<0.0001). The highest IgG and IgA level were observed in fibro-cavernous TB. The presence of cavity was associated only with IgG anti 38+16 kDa (P<0.001). IgA level was the highest in caseous pneumonia. IgM antibody production was not associated with any clinical and radiological factor, but only with the male gender. Age was independently and inversely associated with IgG anti 38 kDa+LAM level and IgM anti 38 kDa+LAM. We conclude that the humoral immune response to mycobacterial antigens is highly heterogeneous and varies with the stage of TB. IgG antibody level is higher in most advanced and extensive forms of the disease.

Neutrophil to lymphocyte ratio associated with prognosis of lung cancer.

PURPOSE: Many studies recently focus on complicated and expensive genomic tests, but the prognostic values of biochemical markers which are easily obtained in clinics are largely overlooked and without further exploration. This study assesses the association of neutrophil-lymphocyte-ratio (NLR) with prognosis of lung cancer patients. METHODS: In 1032 patients with histologically confirmed lung cancer, the association of pretreatment NLR values with overall survival (OS) was evaluated using a Cox proportional hazards model and the temporal relationship of longitudinal NLR was assessed using a mixed effects model. RESULTS: Compared to the patients with a low pretreatment NLR value, those with elevated NLR exhibited a statistically significant worse OS with a hazard ratio (HR) of 1.50 (P < 0.0001) after adjusting for age, gender, race, smoking status, drinking status, tumor stage, tumor grade, histology, and treatments. A significant trend of increasing HRs along with increasing NLR values was observed. The increased risk of death conferred by pretreatment NLR values reached a peak level around 2 years after diagnosis. Moreover, in longitudinal analysis, we observed a trend of dramatically increased NLR values in patients who died during follow-up, but stable NLR values in those who were still alive, with a significant interaction of death-alive status with follow-up time (P < 0.0001). CONCLUSIONS: Elevated NLR is a potential biomarker to identify lung cancer patients with poor prognosis and should be validated in a future clinical trial.

Multi-gene epigenetic silencing of tumor suppressor genes in T-cell lymphoma cells; delayed expression of the p16 protein upon reversal of the silencing.

To understand better T-cell lymphomagenesis, we examined promoter CpG methylation and mRNA expression of closely related genes encoding p16, p15, and p14 tumor suppressor genes in cultured malignant T-cells that were derived from cutaneous, adult type, and anaplastic lymphoma kinase (ALK)-expressing T-cell lymphomas. p16 gene was epigenetically silenced in all but one of the 10 malignant T-cell lines examined, p15 gene silenced in roughly half of the lines, and p14 was the least frequently affected. Extensive methylation of the p16 promoter was seen in six out of 10 cutaneous T-cell lymphoma patient samples and corresponded with lack of p16 protein expression in the cases examined. Treatment of cultured T-cells with the DNA methyltransferase inhibitor, 5-aza-2-deoxy-cytidine, resulted in reversal of the p16 gene silencing. However, expression of p16 protein was delayed in relationship to p16 promoter demethylation and required up to 3 weeks to occur, seemingly reflecting late activation of the p16 gene. These findings indicate that epigenetic silencing affects in T-cell malignancies, often simultaneously, several tumor suppressor genes that impact on key cell functions. The observed differential silencing of p16 and p14, and to a lesser degree p15 gene, indicates that the silencing is governed by precise, promoter region-specific mechanisms. The study provides also further rationale for treatment of at least some types of T-cell lymphomas with DNA methyltransferase inhibitors to target the epigenetically silenced tumor suppressor genes.