Lattice-based mesoscale simulations and mean-field theory of cell membrane adhesion.

Adhesion of cell membranes involves multi-scale phenomena, ranging from specific molecular binding at Angstrom scale all the way up to membrane deformations and phase separation at micrometer scale. Consequently, theory and simulations of cell membrane adhesion require multi-scale modeling and suitable approximations that capture the essential physics of these phenomena. Here, we present a mesoscale model for membrane adhesion which we have employed in a series of our recent studies. This model quantifies, in particular, how nanoscale lipid clusters physically affect and respond to the intercellular receptor-ligand binding that mediates membrane adhesion. The goal of this Chapter is to present all details and subtleties of the mean-field theory and Monte Carlo simulations of this mesoscale model, which can be used to further explore physical phenomena related to cell membrane adhesion.

Endometriosis Is Associated with Functional Polymorphism in the Promoter of Heme Oxygenase 1 (HMOX1) Gene.

Endometriosis is a common gynecological disorder characterized by the ectopic growth of endometrial-like tissue outside the uterine cavity. Etiopathogenesis of endometriosis is poorly understood; it is plausible, however, that the disease may be associated with oxidative stress related to local heme and iron metabolism. Therefore, the aim of the study was to reveal a possible association of endometriosis with a stress-inducible heme oxygenase 1 (HMOX1). For this purpose, 228 patients with clinically confirmed endometriosis and 415 control parous women from general Polish population were examined for functional -413A>T (rs2071746) single-nucleotide polymorphism (SNP) and (GT)n dinucleotide repeat length polymorphism in the promoter of HMOX1 gene. In addition, -413A>T SNP was assessed by the specific TaqMan® SNP Genotyping Assay, and (GT)n polymorphism was determined by PCR product size analysis. We found that endometriosis is associated with an increased frequency of -413A(GT)31,32 haplotype (OR (95%CI) = 1.27 (1.01-1.60), p = 0.0381) and -413A(GT)31,32 homozygous genotype [OR (95%CI) = 1.51 (1.06-2.17), p = 0.0238]. These data suggest that endometriosis is associated with functional polymorphism of HMOX1 gene, and this gene may play a part in the pathogenesis of this disorder.

The impact of HLA-G, LILRB1 and LILRB2 gene polymorphisms on susceptibility to and severity of endometriosis.

Endometriosis is a disease in which endometriotic tissue occurs outside the uterus. Its pathogenesis is still unknown. The most widespread hypothesis claims that ectopic endometrium appears as a result of retrograde menstruation and its insufficient elimination by immunocytes. Some reports have shown expression of non-classical HLA-G molecules on ectopic endometrium. HLA-G is recognized by KIR2DL4, LILRB1 and LILRB2 receptors on natural killer (NK) and other cells. These receptors are polymorphic, which may affect their activity. In this study we investigated whether HLA-G, KIR2DL4, LILRB1 and LILRB2 polymorphisms may influence susceptibility to endometriosis and disease progression. We used polymerase chain reaction (PCR), PCR-restriction fragment length polymorphism (PCR-RFLP) and allelic discrimination methods with TaqMan SNP Genotyping Assays for typing of 276 patients with endometriosis and 314 healthy fertile women. The HLA-G rs1632947:GG genotype was associated with protection against the disease and its severe stages; HLA-G rs1233334:CT protected against progression; LILRB1 rs41308748:AA and LILRB2 rs383369:AG predisposed to the disease and its progression. No effect of KIR2DL4 polymorphism was observed. These results support the role of polymorphisms of HLA-G and its receptors LILRB1 and LILRB2 in susceptibility to endometriosis and its progression.

KIR2DS5 in the presence of HLA-C C2 protects against endometriosis.

Endometriosis is defined as the presence of functional endometrial tissue outside the uterine cavity. Several hypotheses have attempted to explain the etiology and pathogenesis of endometriosis. Recently, it has been suggested that a defect of the natural killer (NK) activity in the recognition and lysis of endometrial cells is one of the crucial points in the development of this disease. Natural killer cells can express killer immunoglobulin-like receptors (KIR), which recognize class I human leukocyte antigens on target cells. We asked whether polymorphisms in KIR, HLA-C, and HLA-B genes are risk factors for endometriosis. We tested 153 women with endometriosis diagnosed on the basis of laparoscopic and histological examination, and 213 control healthy women, who gave birth to at least one child. The frequency of KIR genes in patients was similar to that in controls except for KIR2DS5, which exerted a protective effect only in HLA-C C2-positive individuals. Moreover, KIR2DS5-positive women with endometriosis had 13 times lower chance that the disease would occupy the peritoneum than KIR2DS5- and KIR2DS4del-negative ones (OR = 0.077, P = 0.0061). Similarly, KIR2DS4del-positive endometriotic persons had 11 times lower chance for peritoneal disease (OR = 0.094, P < 0.001). Negative linkage disequilibrium between KIR2DS5 and KIR2DS4del indicates that these genes are mutually exclusive. Our data suggest that KIR2DS5 may be associated with protection from endometriosis, whereas KIR2DS4del seems to be associated with higher disease stages, possibly by exclusion of protective KIR2DS5.

Peritoneal cytokines and adhesion formation in endometriosis: an inverse association with vascular endothelial growth factor concentration.

OBJECTIVE: To evaluate inflammatory/angiogenic cytokines-interleukin-1ß (IL-1ß), IL-6, IL-8, IL-12, interferon-γ (IFN-γ), tumor necrosis factor (TNF), and vascular endothelial growth factor A (VEGF-A)-in the peritoneal fluid of patients with endometriosis in relation to the occurrence and severity of pelvic adhesions and in control women without pelvic pathology. DESIGN: Case-control study. SETTING: University research institution and hospital. PATIENT(S): Sixty-five women with laparoscopically and histopathologically confirmed endometriosis, including 40 women with pelvic adhesions, and 37 control women without pelvic pathology. INTERVENTION(S): Peritoneal fluid aspirated during routine diagnostic laparoscopic examination. MAIN OUTCOME MEASURE(S): Cytokines evaluated in the peritoneal fluid via specific enzyme-linked immunosorbent assays. RESULT(S): Endometriosis and the revised American Fertility Society score of this disease were associated with statistically significantly increased levels of peritoneal IL-6 and IL-8 whereas the incidence and score of endometriosis-related pelvic adhesions were negatively associated with increased levels of VEGF-A. Notably, the concentration of VEGF-A predicted adhesion development and severity after adjustment for endometriosis severity. The adhesion score also correlated with increased levels of IL-6; however, after adjustment for endometriosis severity, the effect of this cytokine was no longer statistically significant. CONCLUSION(S): Increased levels of VEGF-A may be associated with a decreased rate of pelvic adhesion formation in the course of endometriosis.

Expression of ghrelin and its receptors in ovarian endometrioma.

Endometriosis is a common gynaecological disorder manifesting by implantation and growth of endometrial tissue outside the uterine cavity. The evidence accumulates that endometriosis may be associated with abrogated regulation of energy balance. Ghrelin is one of the most important orexigenic factor which may also play a role in regulation of inflammatory and angiogenic reactions. The present study was aimed at investigating expression profile of ghrelin and its receptors (GHSR1α and GHSR1ß) in endometriotic lesions. The study included ovarian cysts and peritoneal fluid specimens obtained laparoscopically from 20 women with revised American Fertility Society stage III or IV endometriosis. Expression of specific mRNAs was assessed by reverse transcription-polymerase chain reaction. Expression of ghrelin and GHSR1α protein was studied by immunohistochemical staining with specific antibodies. Ghrelin and its receptors mRNA expression was found in all tested specimens. Specific mRNAs for these factors were also expressed in the peritoneal leukocytes. Immunohistochemical staining revealed expression of ghrelin and GHSR1α both in glandular endometrioid epithelium and in some stromal cells, particularly in some fibroblasts, blood vessels and infiltrating leukocytes. Co-localization of ghrelin and its receptors strongly suggests that this neuropeptide may affect development and growth of endometriotic lesions and may influence local inflammatory and angiogenic response.

Increased levels of human neutrophil peptides 1, 2, and 3 in peritoneal fluid of patients with endometriosis: association with neutrophils, T cells and IL-8.

Endometriosis is a common gynaecological disorder characterized by the presence of endometrial tissue outside the uterine cavity. This disease is associated with pelvic inflammation and displays some features of autoimmune disorder. Human neutrophil peptides 1, 2, and 3 (HNP 1-3) belonging to α-defensin family play a crucial role in innate immunity against infections and may exert immunoregulatory effects. They may play a role in various inflammatory reactions; however, their role in endometriosis has not been studied. Therefore, the aim of the present study was to evaluate HNP 1-3 in the peritoneal fluid of 67 patients with endometriosis and 16 healthy control women in relation to peritoneal leukocyte subpopulations (neutrophils, T cells, and macrophages) and inflammatory cytokines (IL-6 and IL-8). HNP 1-3, IL-6 and IL-8 were evaluated in the peritoneal fluid by specific enzyme-linked immunosorbent assays (ELISA), and peritoneal leukocyte subpopulations were evaluated by flow cytometry. We found that the levels of HNP 1-3 were significantly increased in the peritoneal fluid of endometriosis patients, compared with control women, and correlated with severity of the disease. Endometriosis was also associated with increased concentrations of peritoneal neutrophils. In endometriosis the levels of HNP 1-3 strongly correlated with concentrations of neutrophils, T cells and IL-8. HNP 1-3 levels were not associated with peritoneal IL-6 or macrophages. These data suggest that HNP 1-3 and neutrophils might play a role in immunopathogenesis of endometriosis and may be worth evaluating as targets for anti-endometriosis therapy.

PTPN22/LYP 1858C>T gene polymorphism and susceptibility to endometriosis in a Polish population.

Endometriosis is a common gynaecological disorder due to ectopic implantation of endometrial tissue. It is manifested by pelvic inflammation and abrogation of cell-mediated immunity and may be also characterised by autoantibody production, thus suggesting that endometriosis might be an autoimmune disorder. Genetic factors also play a role in the aetiopathogenesis of this disease. Therefore, the present study was aimed at testing the association of endometriosis with the PTPN22/LYP 1858C> T gene polymorphism, which appears to be related to the development of a variety of autoimmune disorders. The study included 171 Polish patients of Caucasian origin with laparoscopically and histopathologically confirmed endometriosis and 310 unrelated, ethnically matched control individuals. DNA and serum were isolated from the peripheral blood. The PTPN22/LYP 1858C> T polymorphism was typed using a PCR-RFLP method. Anti-nuclear (ANA) and anti-cardiolipin (ACA) autoantibodies were detected by the Hep-2 indirect immunofluorescence test and a specific ELISA respectively. No statistically significant differences were found in distribution of C and T PTPN22/LYP alleles and genotypes in patients with endometriosis compared with the control population. However, on exploratory analyses we noted that the PTPN22/LYB T allele and the TT genotype may be associated with the prevalence of double positivity for ANA and ACA (p=0.003 by chi(2) test for trend and p=0.009 by Fisher's exact test respectively). The results of the present study show that endometriosis in a Polish population is not associated with the PTPN22/LYP 1858C> T gene polymorphism. The putative effect of the PTPN22/LYP genotype on the development of autoantibodies is potentially interesting, but it should be verified in further studies.

Elevated ghrelin levels in the peritoneal fluid of patients with endometriosis: associations with vascular endothelial growth factor (VEGF) and inflammatory cytokines.

OBJECTIVE: To study ghrelin concentrations in the peritoneal fluid of women with endometriosis and of control women without pelvic pathology and its associations with the levels of proinflammatory cytokines and vascular endothelial growth factor (VEGF). DESIGN: Case-control study. SETTING: University research institution and hospital. PATIENT(S): Forty-six nonobese women with laparoscopically and histopathologically confirmed endometriosis and 20 control women without pelvic pathology. INTERVENTION(S): Peritoneal fluid was aspirated during routine diagnostic laparoscopic examination. MAIN OUTCOME MEASURE(S): Concentrations of ghrelin and inflammatory cytokines (interleukin [IL]-1 beta, IL-6, tumor necrosis factor [TNF], and VEGF) in the peritoneal fluid were evaluated by specific enzyme immunoassay and enzyme-linked immunosorbent assays, respectively. RESULT(S): Ghrelin concentrations in the peritoneal fluid of women with endometriosis were significantly increased as compared with control subjects. Peritoneal ghrelin levels in patients with endometriosis were strongly positively associated with VEGF (r(s) = 0.625). There was no correlation between ghrelin and IL-1 beta, IL-6, or TNF. CONCLUSION(S): The results of the present study show that endometriosis is associated with increased peritoneal ghrelin levels. The association between ghrelin and endometriotic lesion vascularization remains to be elucidated.

A relationship between increased peritoneal leptin levels and infertility in endometriosis.

Endometriosis is a common, complex and chronic disease related to ectopic implantation and growth of endometrial tissue that may manifest by pelvic pain, and accounts for over 20% of all cases of infertility in women. Endometriosis may be associated with increased levels of leptin in peritoneal fluid. However, the association of leptin with infertility has not been definitely documented. Therefore, the aim of the present study was to search for a relationship between concentrations of peritoneal-fluid leptin and patients' clinical status. The study included 56 patients being diagnosed for infertility and/or pelvic pain. Peritoneal fluid was aspirated during routine laparoscopic examination. Concentrations of leptin in peritoneal fluid were evaluated by a specific enzyme-linked immunosorbent assay. The results revealed that the levels of peritoneal-fluid leptin did not correlate with different stage of endometriosis. However, they correlated with body mass index. Leptin levels were significantly higher in infertile patients than in patients with pelvic pain (p = 0.0023 by Mann-Whitney U test or p = 0.0045 by analysis of variance). It may suggest that increased leptin levels in the peritoneal fluid may play a role in pathogenesis of infertility.

Association of leptin with inflammatory cytokines and lymphocyte subpopulations in peritoneal fluid of patients with endometriosis.

INTRODUCTION: Endometriosis is a common, complex and chronic disease related to ectopic implantation and growth of endometrial tissue that may manifest by pelvic inflammatory reactions, chronic pelvic pain and subfertility. Endometriosis may be associated with increased peritoneal fluid leptin levels. Leptin is known to exert immunomodulatory effects; however, an association between leptin and inflammatory reactions in endometriosis has not been documented. Therefore, the aim of this study was to investigate a relationship between leptin concentrations in peritoneal fluid and the levels of peritoneal fluid inflammatory cytokines and mononuclear leukocyte subpopulations. MATERIALS AND METHODS: Peritoneal fluid was aspirated by laparoscopy from 46 women in whom endometriosis had been confirmed by clinical and histopathological examinations and from 10 control women qualified for ART in whom pelvic pathology has been excluded. Concentrations of leptin and inflammatory cytokines (IL-1beta, IL-6, IFN-gamma and TNF) in peritoneal fluid were evaluated by specific ELISAs. Percentage of peritoneal leukocyte subpopulations (CD3+, CD4+, CD8+ and CD14+) was analyzed by FACS using specific monoclonal antibodies. RESULTS: Leptin concentrations in peritoneal fluid correlated negatively with concentrations of IL-1beta and IFN-gamma (r(s)=-0.38, p=0.01 and r(s)=-0.31, p=0.03, respectively) and correlated positively with the percentage of CD3+ pan-T cells (r(s)=0.69, p=0.009) and CD4+ T helper cells (r(s)=0.74, p=0.036). CONCLUSIONS: Increased leptin levels in peritoneal fluid from endometriosis patients may affect local inflammatory/immune reactions, especially infiltration of CD4+ T helper cells. Thus, leptin may play an important role in the immunopathogenesis of endometriosis.

The calcium-sensing receptor and vitamin D receptor expression in tertiary hyperparathyroidism.

The parathormone (PTH) production is controlled by calcium and vitamin D, which interact with the calcium-sensing receptor (CaSR) and vitamin D receptor (VDR), respectively. All of these elements control calcium homeostasis, which is crucial for many physiological processes. Thus, impairment of the upstream component of this system, e.g. a decrease of CaSR and/or VDR, could result in hyperparathyroidism (HPTH). Therefore, the aim of this study was to assess the expression of CaSR and VDR in a tertiary form of HPTH (T-HPTH). The study involved 19 T-HPTH patients qualified for parathyroidectomy and 21 control parathyroids harvested from multi-organ cadaver donors. The small fragments of harvested glands were homogenized and used for Western blot analysis, whereas the remaining tissues underwent routine hematoxylin-eosin staining or immunostaining for CaSR and VDR. Among 64 T-HPTH parathyroids, 58 revealed the morphology of benign hyperplasia, 2 were identified as adenoma and 4 were classified as normal; some glands displayed a mixed histological phenotype. Western blot analysis revealed a decrease of CaSR and VDR in hyperplasia and adenoma-derived samples. However, no correlation between the types of hyperplasia and receptor expression was observed. On the other hand, microscopic analysis of CaSR- and VDR-immunostained sections revealed a highly differentiated and significantly decreased mean expression of both receptors, which correlated with parathyroid histology. The reason behind the impaired expression of CaSR and VDR in T-HPTH is unclear. It presumably results from constant parathyroid stimulation at the stage of S-HPTH, followed by further development of polyclonal autonomy. However, the verification of this thesis requires further study.

Influence of pentoxifylline on natural cytotoxicity and expression of granzymes and PI-9, a specific granzyme B inhibitor.

Pentoxifylline (PTX) is an unspecific inhibitor of phosphodiesterase activity that increases intracellular concentration of cyclic nucleotides, mainly cAMP. Since PTX improves microcirculatory blood flow, it is commonly and often chronically used in peripheral vascular diseases. On the other hand PTX also displays a variety of immunomodulatory activities. PTX inhibits natural cytotoxicity and it has previously been suggested that it could partially act also through its influence on perforin/granzyme-dependent pathways. However, the underlying mechanisms are obscure and it remains unknown whether PTX inhibits natural cytotoxicity influencing only leukocytes or also acting on target cells. In this study, we show that PTX inhibits expression of granzyme A in human leukocytes probably due to suppression of phosphodiesterase activity. Contrary, PTX does not affect expression of granzyme B and H. On the other hand we hypothesized that PTX could inhibit natural cytotoxicity not only affecting leukocytes but also due to generation of resistance to leukocyte-mediated cytotoxicity in target cells e.g. through overexpression of PI-9, a specific granzyme B inhibitor. We found that at the mRNA level, PTX stimulates expression of PI-9 in K562 cells. However, we did not observe such an influence at the protein level, in either K562 cells or in human leukocytes. It may suggest that other PTX-triggered molecular events may interfere with PI-9 overexpression in these cells at the further, post-transcriptional levels. According to these results, PTX did not affect resistance of target cells to natural cytotoxicity. Altogether, PTX inhibits natural cytotoxicity affecting mainly effector but not target cells and in case of the effector cells, besides previously reported mechanisms, it can also inhibit granzyme A expression.

P-glycoprotein expression influences the result of 99mTc-MIBI scintigraphy in tertiary hyperparathyroidism.

Precise localization of parathyroid glands using 99mTc-labeled hexakis-2-methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy could be affected by various biological factors. There is increasing evidence that radiotracer retention could be controlled by members of multidrug resistance (MDR) system, especially P-glycoprotein (P-gp). Since the role of P-gp in tertiary hyperparathyroidism (T-HPTH) scintigraphic studies is poorly recognized, the aim of the study was to compare the correlation between parathyroid P-gp expression and results of their scintigraphy in T-HPTH versus primary hyperparathyroidism (P-HPTH). P-HPTH (n = 19) and T-HPTH (n = 18) patients were subjected to 99mTc-MIBI scintigraphy followed by surgical treatment. The parathyroid glands were assessed in routine hematoxylin-eosin staining and P-gp expression was analyzed using immunohistochemistry. Parathyroids collected during cadaver donor multi-organ harvesting were used as a control. It has been found that P-HPTH-derived parathyroid glands with predominating adenoma morphology expressed less P-gp, as compared to P-gp-rich T-HPTH glands, mainly displaying nodular or diffused hyperplasia phenotype. This finding reversely correlated with results of 99mTc-MIBI scintigraphy. However, we did not observe any difference in P-gp expression nor scintigraphy result between nodular or diffused hyperplasia. Altogether, these data suggest that P-gp overexpression in T-HPTH could be responsible for decreased sensitivity of 99mTc-MIBI scintigraphy in those patients. Therefore, the recently proposed reduced neck exploration or limited parathyroid resection on the basis of scintigraphy could create the risk of persisted/recurrent hyperparathyroidism. However, this problem requires further study.

Impaired apoptosis of lymphocytes derived from patient with decreased expression of caspase-8 results in Alps-like phenotype.

Human autoimmune lymphoproliferative syndrome has been described as a result of various mutations concerning genes encoding receptor CD95 and/or its ligand - CD178. However, recently, several cases with identical clinical manifestation, despite a normal structure of CD95 or CD178 have also been reported. In this study we analyzed PBMC obtained from patient with clinically overt lymphoproliferative disorder. Using in vitro assays as well as molecular methods we tested expression and biological activity of CD95 and CD178 molecules. We found that analyzed patient's lymphocytes displayed normal cytotoxic activity against CD95-bearing targets. However, CD95-dependent induction of apoptosis in analyzed lymphocytes was diminished, as compared to healthy control. Surprisingly, the molecular studies did not reveal any abnormalities in structure of patient-derived CD95 receptor molecule. Therefore, expression of other factors involved in CD95-mediated signaling pathway was estimated using RNase protection assay. The expression of FADD was comparable to that of healthy control. However, it has been found that patient-derived lymphocytes expressed reduced amount of caspase-8 mRNA, as compared to control subject cells. This report confirms previous observations that lymphoproliferative disorder could be associated not only with CD95 and/or CD178 mutations, but also with dysfunction of other components of apoptosis induction pathway. However, the detailed molecular mechanism of observed abnormalities in caspase-8 expression remains to be elucidated.

Persisted/recurrent hyperparathyroidism associated with development of multi-drug resistance phenotype and proliferation of parathyroid transplants.

The surgical treatment of secondary hyperparathyroidism (HPTH) requires sub-total excision of parathyroid glands or total excision with their autotransplantation. Although this approach has been considered as a safe method of treatment, in this report we describe persisted/recurrent HPTH after parathyroid transplantation. Due to parathormone (PTH) hypersecretion and uncontrolled proliferation, the parathyroid grafts were removed and used for generation of cell cultures, which further have been subjected to in vitro studies. As a control we used parathyroid tissue, obtained during multiorgan harvesting. We found increased proliferation and up-regulated PTH production by the graft-derived, but not control in vitro cultured cells. Moreover, due to decrease of in vivo radiotracer uptake by parathyroid grafts, the expression of multi-drug resistance-involved factors, including P-glycoprotein (P-gp/mdr1), multi-drug resistance-associated protein (mrp) and bcl-2 have been investigated using RT-PCR. The analysis revealed increased expression of both, mdr1 and mrp in graft-derived cells, in contrast to control cells, which did not express P-gp/mdr1 or mrp. However, we did not observe any difference in expression of bcl-2 between analyzed cells. The up-regulated expression of P-gp/mdr1 on graft-derived cells was further confirmed by immunofluorescence studies. The described case indicates potential risk associated with transplantation of parathyroid tissue. Our results confirm a role of MDR phenomenon in occurrence of false negative results in parathyroid tissue scintigraphy studies. Moreover, they indicate that standard histological examination of transplanted material could not be sensitive enough to exclude any potential danger of abnormal graft progression. Thus, they could support the concept to use encapsulated parathyroid transplants.

Influence of pentoxifylline on perforin expression in human PBMC.

Pentoxifylline (PTX) is a methylxanthine derivative that unspecifically inhibits phosphodiesterase activity and thus, it increases intracellular concentration of cyclic nucleotides. Currently, PTX is commonly and chronically used in peripheral blood vessel diseases. Besides its well-known influence on rheologic properties of blood, PTX has also been found to decrease secretion of some cytokines such as IL-12, TNF and IFN-gamma and thus it could exert immunomodulatory activity. Furthermore, PTX inhibits lymphocyte cytotoxicity affecting the perforin-dependent pathway, both in humans and animals. It has also been shown recently that in some murine models, PTX promotes tumor growth. Such a phenomenon, at least partially, could result from PTX-dependent inhibition of natural cytotoxicity. However, the detailed mechanism of PTX influence on cytotoxic activity in humans has not been established. We hypothesized that PTX-dependent inhibition of natural cytotoxicity could result from decrease in perforin expression. In this study, it was shown that pentoxifylline only moderately inhibits perforin expression at the mRNA level in human peripheral blood mononuclear cells (PBMC), and this effect seems to be independent of intracellular cAMP concentration. On the other hand, PTX did not significantly influence perforin expression at the protein level. These results suggest that in humans, contrary to murine models, inhibition of perforin-dependent natural cytotoxicity through pentoxifylline does not result from changes in perforin production. Presumably, influence of PTX on natural cytotoxicity could be caused by e.g. interference with lymphocyte degranulation. Moreover, also other possibilities, such as PTX influence on conformational changes of perforin molecules and/or its influence on susceptibility of target cells to pore-forming of polyperforins cannot be excluded.

Molecular therapy versus standard treatment in allergy (Review).

The increasing knowledge concerning pathomechanism of allergy creates new perspectives for treatment. Standard methods currently applied in allergy act multidirectional, usually being crude and unselective. Moreover, such therapy does not eliminate the cause of hyperresponse reaction and often fails to restore the immunological balance. It is also noteworthy that the conventional therapy frequently affects different tissues not directly involved in allergic reaction and thus it may exert numerous side effects. The hypersensitivity was found to be related to some cytokines network abnormalities. Among cytokines, there are a few, well-recognized factors e.g., interleukin-4 (IL-4), IL-5 and IL-13, which play a pivotal role in allergy. Thus, the major goal for causal allergy treatment should be restoration of the balance in cytokine-mediated regulation of allergen-driven immunological response. It could be achieved by administration of missing cytokines, e.g., interferon-gamma (IFN-gamma) and/or down regulation of excessive one, e.g., IL-4, IL-13. Such a therapy, directed towards only specific, allergy-involved molecules, should not affect the other by-standing particles or reactions. Obviously, a good target for this kind of treatment could be immunoglobulin E (IgE) that is causally related to anaphylactic response. Furthermore, especially promising objectives for molecular therapy seem to be some cytokine receptors and signal transduction pathways and some adhesion molecules. The most recent therapeutical strategies attempting to restore immunological balance in allergy are presented. They include, among others, anti-cytokine antibodies, their soluble receptors, antisense oligonucleotides and small interfering RNA. Although many of these topical methods are still in the trial phase, we suppose they will become a clinical reality in the near future.

Differential influence of pentoxifylline on murine colon adenocarcinoma- and melanoma-derived metastatic tumor development in lungs.

Pentoxifylline (PTX), a methylxanthine derivative, is commonly and in most cases chronically used in patients suffering from peripheral vascular diseases. It increases erythrocyte flexibility, reduces blood viscosity and improves microcirculatory flow. Moreover, PTX has been found to enhance anticancer activity of some chemotherapeutic agents and ionizing irradiation. On the other hand, PTX has been recently shown to inhibit anticancer response and promote murine tumor growth in liver. In this study we show that PTX facilitates development of murine colon adenocarcinoma- but not melanoma-derived tumors also in lungs. It could suggest that tumor-promoting PTX activity is tissue-independent, although, it might depend on the cancer cell line.