Ursodeoxycholic and chenodeoxycholic bile acids attenuate systemic and liver inflammation induced by lipopolysaccharide in rats.

Bacterial lipopolysaccharide (LPS) induces general inflammation, by activating pathways involving cytokine production, blood coagulation, complement system activation, and acute phase protein release. The key cellular players are leukocytes and endothelial cells, that lead to tissue injury and organ failure. The aim of this study was to explore the anti-inflammatory, antioxidant, and cytoprotective properties of two bile acids, ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) in LPS-induced endotoxemia in rats. The experiment involved six distinct groups of Wistar rats, each subjected to different pretreatment conditions: control and LPS groups were pretreated with propylene glycol, as a bile acid solvent, while the other groups were pretreated with UDCA or CDCA for 10 days followed by an LPS injection on day 10. The results showed that both UDCA and CDCA reduced the production of pro-inflammatory cytokines: TNF-α, GM-CSF, IL-2, IFNγ, IL-6, and IL-1ß and expression of nuclear factor-κB (NF-κB) induced by LPS. In addition, pretreatment with these bile acids showed a positive impact on lipid profiles, a decrease in ICAM levels, an increase in antioxidant activity (SOD, |CAT, GSH), and a decrease in prooxidant markers (H2O2 and O2-). Furthermore, both bile acids alleviated LPS-induced liver injury. While UDCA and CDCA pretreatment attenuated homocysteine levels in LPS-treated rats, only UDCA pretreatment showed reductions in other serum biochemical markers, including creatine kinase, lactate dehydrogenase, and high-sensitivity troponin I. It can be concluded that both, UDCA and CDCA, although exerted slightly different effects, can prevent the inflammatory responses induced by LPS, improve oxidative stress status, and attenuate LPS-induced liver injury.

Anti-inflammatory and immunomodulatory effects of Biodentine on human periapical lesion cells in culture.

AIM: To evaluate the effect of Biodentine eluate on cytotoxicity and production of pro- and anti-inflammatory cytokines and osteodestructive/osteoprotective cytokines in cultures of human periapical lesion cells. METHODOLOGY: Conditioned Biodentine Medium (CBM) was prepared according to ISO 10993-12, by incubating Biodentine in RPMI medium (0.2 g mL-1 ) for 3 days at 37 °C. CBM contained both released microparticles and leachable soluble components. Inflammatory cells were isolated from 22 human periapical lesions after apicectomy or tooth extraction, by collagenase/DNase digestion, and cultured in several dilutions of CBM. The composition of periapical lesion cells was determined by morphological criteria, cytotoxicity was quantified by MTT and flow cytometric apoptosis/necrosis assays, whereas the levels of produced cytokines in cell culture supernatants were measured by flow cytometry and ELISA. Student t-test and Friedman test with Dunn's post-test were used for comparison of parametric and nonparametric variables, respectively. RESULTS: Undiluted (100%), 75% and 50% CBM were cytotoxic for periapical lesion cells due to induction of both necrosis (100% CBM) and apoptosis (75% and 50% CBM). Noncytotoxic concentrations of CBM (25%) inhibited the production of pro-inflammatory cytokines: TNF-α, (P < 0.005); IL-1ß (P < 0.01); IL-6 (P < 0.005) and chemokines IL-8: (P < 0.005); MCP-1 (P < 0.005), stimulated the production of anti-inflammatory cytokine (IL-10; P < 0.005), Th2 cytokines: IL-4, IL-5 and IL-33 (all P < 0.01), and IL-17A (P < 0.01). The concentration of CBM (12.5%) inhibited the production of IL-6 (P < 0.05), IL-8 (P < 0.01) and MCP-1 (P < 0.005) and augmented the production of IL-10 (P < 0.05). No significant effects on Th1-related cytokines (IFN-γ and IL-12) and IL-23 were detected with 25% and 12.5% CBM concentrations. Both CBM concentrations inhibited the production of osteolytic receptor activator of nuclear factor kappa-Β ligand (RANKL), dose dependently (P < 0.005 and P < 0.01, respectively). Higher CBM concentrations decreased RANKL/osteoprotegerin (OPG) ratio (P < 0.05), without significant influence on the levels of osteoprotective OPG. CONCLUSION: Biodentine possesses immunomodulatory properties by suppressing pro-inflammatory and augmenting anti-inflammatory cytokines. Together with the reduction of osteodestructive mediators, this novel root-end filling cement could be beneficial for healing and bone reparation after the surgical treatment of periapical lesions.

IL-17 and glutamate excitotoxicity in the pathogenesis of multiple sclerosis.

Immunoinflammatory-mediated demyelination, the main pathological feature of multiple sclerosis (MS), is regularly accompanied by neurodegenerative processes, mostly in the form of axonal degeneration, which could be initiated by glutamate excitotoxicity. In the current study, the relationship between Th17-mediated inflammatory and excitotoxic events was investigated during an active phase of MS. Cerebrospinal fluid (CSF) of patients with MS and control subjects was collected, and IL-17A and glutamate levels were determined. IL-17A level was significantly higher in patients with MS; whereas no statistically significant changes in glutamate concentrations were found. There was a direct correlation between IL-17A and glutamate levels; IL-17A levels were also associated with the neutrophil expansion in CSF and blood-brain barrier disruption. However, IL-17A level and the number of neutrophils tended to fall with disease duration. The results suggest that Th17 cells might enhance and use glutamate excitotoxicity as an effector mechanism in the MS pathogenesis. Furthermore, Th17 immune response, as well as neutrophils, could be more important for MS onset rather than further disease development and progression, what could explain why some MS clinical trials, targeting Th17 cells in the later stage of the disease, failed to provide any clinical benefit.

E-cadherin expression in acquired cholesteatoma.

OBJECTIVES: The epithelial cell adhesion molecule E-cadherin is important for maintenance normal tissue architecture and for cell-cell communication and immune cell migration. E-cadherin is also present in cholesteatomas. This study determined E-cadherin expression in acquired cholesteatomas and analyzed its expression according to cholesteatoma clinical and histological characteristics. METHODS: We investigated E-cadherin expression in 30 samples from operated patients with acquired middle ear cholesteatomas that were classified according to their clinical and histological characteristics. E-cadherin expression in cholesteatoma was determined immunohistochemically. A semi quantitative method was used to determine the index of expression of E-cadherin and t-tests, Mann-Whitney U tests and Spearman correlation analysis were used for statistical analysis. RESULTS: We found significant expression of E-cadherin on CD1, CD3 total, CD4 (p < 0.05), high expression of E-cadherin on CD8 total and CD19/CD38 lymphocytes (p < 0.01) and very high expression of E-cadherin on mast cells and antigen-presenting cells, including Langerhans cells (p < 0.005). We graduated results as no statistically significant (p>0.05), statistically significant (0.05 > p > 0.01), highly statistically significant (0.01 > p > 0.005) and very highly statistically significant (p < 0.005). CONCLUSION: E-cadherin expression was the same in the cholesteatoma matrix in all samples. There were no differences in expression according to the clinical and histological characteristics of the cholesteatomas.

Salivary interleukin-8 levels in children suffering from type 1 diabetes mellitus.

OBJECTIVE: The aim of this study was to investigate the differences between the salivary levels of IL-8 in patients with Type 1 diabetes mellitus (DM) with (DM+P) or without (DM-P) concomitant periodontitis and healthy subjects. The correlations between the levels of these cytokines and clinical periodontal parameters were also established. METHODS: Twenty children and adolescents with Type 1 DM (10 diagnosed with periodontitis, 10 presenting no signs of periodontitis) and a control group consisting of 20 healthy children and adolescents aged 7-18 years were recruited for this study. RESULTS: The Salivary IL-8 level was statistically significantly (p < 0.005) elevated in subjects with Type 1 DM (474.47 +/- 716.76) compared to non-diabetic control group (101.99 +/- 68.32). There was no difference (p > 0.05) in the salivary IL-8 level when subjects with Type 1 DM with concomitant periodontitis were compared to diabetics without periodontitis. When the salivary IL-8 level in subjects with Type 1 DM was correlated with the clinical parameters, no statistical significance was found. CONCLUSION: An elevated salivary IL-8 level in subjects with Type 1 DM without concomitant periodontitis plays a major role in the development of diabetic micro and macroangiopathy and pathogenesis of atherosclerosis. Consequently, this may offer a basis for the assessment of risk, prophylaxis and treatment of diabetic complications.

Response of monocyte-derived dendritic cells to rapidly solidified nickel-titanium ribbons with shape memory properties.

Ni-Ti Shape Memory Alloys (SMAs) have attracted considerable attention as biomaterials for medical devices. However, the biocompatibility of Ni-Ti SMAs is often unsatisfactory due to their poor surface structure. Here we prepared Rapidly Solidified (RS) Ni-Ti SMA ribbons by melt-spinning and their surface was characterised by Auger-electron spectroscopy, X-ray photoelectron spectrometry and scanning electron microscopy. The biocompatibility of the produced ribbons and their immunomodulatory properties were studied on human monocyte-derived dendritic cells (MoDCs). We showed that melt-spinning of Ni-Ti SMAs can form a thin homogenous oxide layer, which improves their corrosion resistance and subsequent toxicity to MoDCs. Ni-Ti RS ribbons stimulated the maturation of MoDCs, as detected by changes in the cells' morphology and increased expression of HLA-DR, CD86, CD40 and CD83 molecules. However, Ni-Ti RS ribbons enhanced the tolerogenic properties of immature MoDCs, which produced higher levels of IL-10 and IL-27, driving the differentiation of IL-10- and TGF-ß-producing CD4+T cells. On the other hand, in the presence of lipopolysaccharide, an important pro-inflammatory biomolecule, Ni-Ti RS ribbons enhanced the allostimulatory and Th1 polarising capacity of MoDCs, whereas the production of Th2 and Th17 cytokines was down-regulated. In conclusion, Ni-Ti RS ribbons possess substantial immunomodulatory properties on MoDCs. These findings might be clinically relevant, because implanted Ni-Ti SMA devices can induce both desired and adverse effects on the immune system, depending on the microenvironmental stimuli.

Effects of conventional versus biocompatible peritoneal dialysis solutions on peritoneal and systemic inflammation, malnutrition and atherosclerosis in CAPD patients.

BACKGROUND: Chronic inflammation, malnutrition and atherosclerosis (MIA syndrome) are important predictors of high mortality in continuous ambulatory peritoneal dialysis (CAPD) patients. We aimed to evaluate the effects of PD solutions (standard vs. biocompatible) on some parameters of MIA syndrome in patients undergoing CAPD. METHODS: 42 stable patients who were on CAPD at least 2.5 years participated in this cross-sectional study. Patients who had severe anemia (Hb < 10 g/l), immunomodulatory therapy, peritonitis or any inflammatory conditions for at least 3 months before the analysis, malignant disease and acute exacerbation of heart failure, were excluded. 21 (50%) patients were treated with standard PD solutions (CAPDP-1), while the remaining 21 (50% of patients) were treated with biocompatible PD solutions (neutral solutions with lower level of glucose degradation products and lower concentration of calcium, CAPDP-2). All patients underwent echocardiography and B-mode ultrasonography of common carotid arteries together with assessments of nutrition status and parameters of systemic and local inflammation. RESULTS: There were no significant differences between the groups concerning age, gender, underlying disease, residual renal function, peritoneal transport characteristics, comorbidity or therapy applied. Patients from group CAPDP-2 had a significantly lower serum level of hs-CRP (3.7 ± 2.6 mg/l vs. 6.3 ± 4.5 mg/l; p = 0.023) and significantly better nutritional status confirmed by mid-arm circumference (p = 0.015), mid-arm muscle circumference (p = 0.002) and subjective global assessment (14.28% of patients in CAPDP-2 vs. 71% of patients in CAPDP-1 were malnourished; p = 0.000). Group CAPD-2 had less frequent left ventricular hypertrophy (p = 0.039), thinner intima-media thickness (p = 0.005), smaller carotid narrowing (p = 0.000) and fewer calcified plaques of common carotide arteries (p = 0.003). No significant difference between the CAPDP groups was observed in serum and effluent levels of inflammatory cytokines (IL-1, IL-6 and TNF-α) and CA-125 effluent level. Logistic regression analysis did not confirm that biocompatibility of PD solutions was an independent predictor of any parameter of MIA syndrome. CONCLUSIONS: According to the present study and logistic regression analysis, the effect of biocompatible CAPD solutions on parameters of malnutrition, inflammation and atherosclerosis have to be confirmed by well-designed and controlled studies in a higher number of patients.

Characterization of rat bone marrow dendritic cells initially primed by Trichinella spiralis antigens.

Pathogen-derived products have the capacity to induce maturation of bone marrow-derived dendritic cells (BMDCs)into populations of effectors cells that polarize Th cells toward Th1 or Th2 phenotype via different mechanisms. Since those mechanisms are not entirely clear for helminths, and almost completely unknown for Trichinella spiralis(TS), we started an investigation of the effects of TS antigens (four different antigens isolated from all three life-cycle stages of parasite)on maturation of BMDCs and their potential to present TS antigens. The expression of MHC class II, costimulatory molecules CD86, CD54, IL-10 and IL-12p70 cytokine production were measured after 2 days of BMDCs cultivation with TS antigens. While parasitic antigens did not significantly alter the expression of MHC II, most of them, except crude muscle larvae antigens, up-regulated the expression of costimulatory molecules. BMDCs, primed with all TS antigens, released increased amounts of IL-10 and decreased amounts of IL-12p70. BMDCs, primed with TS antigens, induced significant proliferation of syngeneic TS sensitized lymph nodes cells and also stimulated the production of IL-4 by T cells purified from of TS infected DA rats. The results indicate that TS stimulated BMDCs leads to the polarization of the immune response towards regulatory and Th2 type.

Evaluation of the stimulatory effect of Epimedium alpinum L. methanolic extract on the immune response in vivo.

The effect of the methanolic extract of the underground parts of Epimedium alpinum L. (MEEA) on the immune response to Keyhole Limpet Hemocyanine (KLH) or alloantigens in vivo was studied in AO rats. Immunization of experimental animals with KLH or allogeneic lymphocytes together with MEEA was followed by an increase in cellularity of draining lymph nodes (LN) and enhanced proliferation of LN lymphocytes after their restimulation with specific antigens in vitro, compared to control rats immunized without MEEA. These effects correlated with an increase in relative values of B, MHC class II+, CD25+ and CD71+ cells, whereas percentages of T cells and both subsets of T cells (CD4+ and CD8+) were not significantly altered. As a consequence of higher LN cellularity, total numbers of all cell subsets in the MEEA-treated group of rats were significantly increased, compared to the corresponding control. The addition of MEEA together with KLH in vitro to LN lymphocytes of rats immunized with KLH or KLH and MEEA in vivo was manifested by significant increase (0.1 microg/ml of MEEA) and decrease (50 microg/ml and 100 microg/ml of MEEA) of cell proliferation, respectively. However, when LN lymphocytes from rats, immunized in vivo with KLH and MEEA, were stimulated in vitro with MEEA together with an anti-alphabeta T cell receptor monoclonal antibody (R73), their proliferation was siginificantly inhibited. Taken together, obtained results suggest that MEEA possesses immunostimulatory activity in vivo, but some components from the extract exert immunosuppressive effects in vitro on previously in vivo activated T cells.

Molecular mechanisms of anticancer activity of natural dietetic products.

The efficiency of dietetic supplements in cancer prevention and treatment is a popular and controversial subject of research. New in vitro and in vivo research results indicate that some dietetic supplements do indeed show anticancer activity. The strongest anticancer action has been demonstrated by natural compounds with multifunctional activity. For instance, antioxidants, which also bind to and modulate the activity of protein kinases involved in signal transduction cascades show both cytostatic and cytotoxic activity towards cancer cells. Other activities such as angiogenesis inhibition, nitric oxide synthase inhibition, and pro-oxidants production have also been observed. Catechins and polyphenols from plant extracts such as green tea show the strongest anticancer activity. The initial clinical trials with some flavonoid molecules are already underway.

Natural zeolite clinoptilolite: new adjuvant in anticancer therapy.

Natural silicate materials, including zeolite clinoptilolite, have been shown to exhibit diverse biological activities and have been used successfully as a vaccine adjuvant and for the treatment of diarrhea. We report a novel use of finely ground clinoptilolite as a potential adjuvant in anticancer therapy. Clinoptilolite treatment of mice and dogs suffering from a variety of tumor types led to improvement in the overall health status, prolongation of life-span, and decrease in tumors size. Local application of clinoptilolite to skin cancers of dogs effectively reduced tumor formation and growth. In addition, toxicology studies on mice and rats demonstrated that the treatment does not have negative effects. In vitro tissue culture studies showed that finely ground clinoptilolite inhibits protein kinase B (c-Akt), induces expression of p21WAF1/CIP1 and p27KIP1 tumor suppressor proteins, and blocks cell growth in several cancer cell lines. These data indicate that clinoptilolite treatment might affect cancer growth by attenuating survival signals and inducing tumor suppressor genes in treated cells.

Ex vivo repair of renal artery aneurysm associated with repairing of abdominal aortic aneurysm. Case report.

A case of right renal artery distal aneurysm associated with juxtarenal abdominal aortic aneurysm in a 75-year-old male, who presented with abdominal and back pain and chronic renal failure, is reported. The abdominal aortic aneurysm was repaired with a bifurcated Dacron graft. The right kidney was simultaneously explanted, ex vivo reconstruction of the renal artery with PTFE graft was performed, followed by autotransplantation of the kidney into the right iliac fossa. In the postoperative course the renal function returned to normal.

Immunomodulatory effect of xylazine, an alpha(2) adrenergic agonist, on rat spleen cells in culture.

Xylazine is an adrenergic alpha(2) agonist, which is used in veterinary medicine as a sedative and anesthetic agent. In this work we found that xylazine administered in vivo at a dose of 2.5 mg/kg enhanced spleen cell proliferation and interleukin 2 (IL-2) production in cultures stimulated with concanavalin A (Con A), whereas doses of 10 and 25 mg/kg were inhibitory. A similar stimulatory (10 microM) and inhibitory (50-500 microM) effect on splenocyte proliferation and IL-2 production was observed in vitro. Clonidine, another alpha(2) adrenergic agonist, only had a stimulatory proliferative effect on splenocytes. Yohimbine, an alpha(2) adrenergic antagonist, abrogated the stimulatory action of both clonidine and xylazine, but not the suppressive proliferative activity of xylazine in vitro. The inhibited proliferation of splenocytes to Con A correlated with increased apoptosis of T cells. The apoptosis was not blocked by yohimbine or antibodies to Fas and Fas-L. N-Nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthase, enhanced proliferation of splenocytes to Con A, partly abrogated the inhibitory effect of xylazine in the proliferation assay, and, only at high concentration (1000 microM), partly suppressed apoptosis of lymphocytes. The enhancing effect of L-NAME on the Con A-induced proliferation of splenocytes correlated with decreased NO production. However, decreased NO production observed in cultures with xylazine was followed by both decreased lymphocyte proliferation and apoptosis. Cumulatively, these results suggest that the immunosuppressive properties of xylazine on splenocytes in vitro are due to increased apoptosis of lymphocytes, predominantly involve NO-independent pathways, and are probably independent of its action through alpha(2) adrenoreceptors.

Expression and function of intercellular adhesion molecule 1 (ICAM-1) on rat thymic macrophages in culture.

The expression of intercellular adhesion molecule 1 (ICAM-1) was studied on freshly isolated rat thymic macrophages (TMF) and after their cultivation in serum-free medium using monoclonal antibody (mAb) 1A 29 and a streptavidin-biotin immunoperoxidase technique. ICAM-1 was expressed on about 80% of freshly isolated TMF. Upon cultivation, the percentage of ICAM-1+ TMF decreased to about 30-40% in 12-day-old culture. Using double immunofluorescence staining it was found that ICAM-1 was expressed both on cortical (R-MC 40+) and CMZ/medullary (R-MC 43+) macrophage subsets. ICAM-1 was up-regulated on TMF in culture by recombinant IFN-gamma, IL1 and TNF-alpha and was down-regulated by dexamethasone. Syngeneic thymocytes bound to cultivated TMF in a rosette form at both 37 degrees C and 4 degrees C. IFN-gamma treatment did not increase the binding formation. The binding between thymocytes and IFN-gamma-stimulated TMF at 37 degrees C was inhibited by pretreatment of TMF with anti-ICAM-1 mAb or pretreatment of thymocytes with anti-LFA-1 mAb, indicating that ICAM-1 on TMF is one of the ligands involved in TMF/thymocyte adhesion and subsequent direct cell-cell communication.

Comparison of signaling pathways involved in apoptosis of a thymocyte hybridoma triggered by a rat thymic medullary epithelial cell line, dexamethasone or T-cell receptor cross-linking.

Using an in vitro co-culture assay we found that a rat medullary thymic epithelial cell (TEC) line (TE-R2.5) induces apoptosis of the BWRT8 thymocyte hybridoma (TH) (CD4(hi)CD8(low) alphabetaTCR(hi)). TH apoptosis induced by this TEC line was predominantly mediated by direct cell-cell contacts and was potentiated by cross-linking of the T cell receptor (TCR) by R73 monoclonal antibody (mAb). Dexamethasone (Dx) also triggered TH apoptosis but inhibited death of these cells induced by TE-R2.5 cells or immobilized R73 mAb. The TEC-induced apoptosis was independent of the LFA-1/ICAM-1 interaction but partly depended on a novel 29 kDa molecule expressed on TE-R2.5 cells. All three types of TH apoptosis were followed by the cleavage of poly-(ADP-ribose)-polymerase and were blocked by a caspase inhibitor Z-Val-Ala-Asp(OMe)-CH(2)F.PKC stimulation by phorbol myristate acetate interfered with the TH apoptosis induced by TE-R2.5 and Dx, but did not modulate the effect of R73 mAb. On the contrary, inhibition of calcineurin with cyclosporine A did not influence the apoptosis induced by TE-R2.5 and Dx, but completely prevented the R73-triggered TH cell death. The TE-R2.5-mediated BWRT8 apoptosis was suppressed by Na-orthovanadate, an inhibitor of protein tyrosine phosphatases (PTP) as well as by genistein, a protein tyrosine kinase (PTK) inhibitor, while both compounds potentiated the effect of Dx. Blocking PTP, but not PTK decreased the proapoptotic effect of R73 mAb. These results, including those using a BWRT8 subclone (BWRT8-MDP.2) which is resistant to TCR-triggered apoptosis, but sensitive to apoptosis stimulated by TE-R2.5 and Dx, indicate that TE-R2.5-induced TH apoptosis in our model is different from apoptosis in other TEC co-culture models, published so far.

A nucleoside analogue, 7-thia-8-oxoguanosine stimulates proliferation of thymocytes in vitro.

7-thia-8-oxoguanosine (immunosine) is a nucleoside analogue with immunoenhancing activity. In this work, its effects on proliferation of thymocytes in vitro were studied. It was found that immunosine stimulated proliferation of thymocytes both of mice and rats. The stimulatory effect depended on antigen presenting cells (APC), since thymocytes depleted of accessory cells did not proliferate to immunosine. In addition, pretreatment of APC with immunosine for 24 h significantly increased proliferation of thymocytes. Immunosine stimulated interleukin 2 (IL-2) production and the expression of activation markers (CD25 and CD71). The upregulation of CD25 (alpha subunit of IL-2R) was detected both on thymocytes and thymic dendritic cells. Proliferation of thymocytes in the presence of immunosine was predominantly mediated by IL-2 since blocking IL-2Ralpha by specific monoclonal antibodies inhibited cell proliferation by 65-85%.

Interspecies differences in expression of cytokeratin polypeptides within thymic epithelium: a comparative immunohistochemical study.

Cytokeratin (CK) polypeptide expression within the thymic epithelium of several mammalian species (mouse, rat, calf, pig, rabbit, and human) has been analyzed by the streptavidin-biotin immunoperoxidase method. Comparative analysis by a large panel of 17 monoclonal antibodies (mAbs) specific for individual CK polypeptides, pairs, or groups showed considerable heterogeneity of thymic epithelial cells (TEC) in each species. In addition, extreme interspecies difference in CK contents was observed. Four main phenotypic zones: the subcapsule/perivascular area, cortex, medulla, and Hassall's corpuscles (HC) were clearly identified, each characterized by different CK expression. Medullary TEC were more heterogenous and shared common CK polypeptides either with subcapsular/perivascular TEC, cortical TEC, or HC, in most species.

Immunocytochemical demonstration of prostaglandin synthase (cyclooxygenase) in thymic macrophages of normal and cyclosporin-treated rats.

As revealed with ED1 and ED2 monoclonal antibodies, macrophages are scattered throughout the thymic tissue. However, in contrast to the cortex and medulla, in the cortico-medullary zone macrophages are large and show strong reactivity with rabbit polyclonal antisera to cyclooxygenase. Only few smaller cortical macrophages also show weaker presence of prostaglandin synthase. After cyclosporin treatment cortical macrophages become strikingly similar to the macrophages of the cortico-medullary zone of the normal thymus. Cortical macrophages become enlarged and develop the strong expression of prostaglandin synthase. Our results show that a specific type of macrophages (with distinct histochemical characteristics, enzyme profile and ultrastructural organization, which is strategically positioned within the thymic tissue--as we demonstrated earlier) possesses the enzyme capacity required for prostaglandin synthesis. After cyclosporin treatment, which interferes with the maturation of thymocytes, cortical macrophages thoroughly change and develop the strong prostaglandin synthase expression, similar to that of normal cortico-medullary zone macrophages.

Immunostimulatory effect of natural clinoptilolite as a possible mechanism of its antimetastatic ability.

PURPOSE: Many biochemical processes are closely related to ion exchange, adsorption, and catalysis. Zeolites reversibly bind small molecules such as oxygen or nitric oxide; they possess size and shape selectivity, the possibility of metalloenzyme mimicry, and immunomodulatory activity. These properties make them interesting for pharmaceutical industry and medicine. METHODS: The experiments were performed on mice. Different biochemical and molecular methods were used. RESULTS: Micronized zeolite (MZ) administered by gastric intubation to mice injected with melanoma cells significantly reduced the number of melanoma metastases. In mice fed MZ for 28 days, concentration of lipid-bound sialic acid (LSA) in serum increased, but lipid peroxidation in liver decreased. The lymphocytes from lymph nodes of these mice provoked a significantly higher alogeneic graft-versus-host (GVH) reaction than cells of control mice. After i.p. application of MZ, the number of peritoneal macrophages, as well as their production of superoxide anion, increased. However, NO generation was totally abolished. At the same time, translocation of p65 (NFkappaB subunit) to the nucleus of splenic cells was observed. CONCLUSION: Here we report antimetastatic and immunostimulatory effect of MZ and we propose a possible mechanism of its action.

Aberrant levels of cytokines within the healing wound after burn injury.

OBJECTIVE: To study the effect of a burn injury on the course of cellular and cytokine changes in a wound and the relationship of these cytokines to the amounts of protein and collagen deposited at the site of the wound. DESIGN: A randomized control trial was done in which one group of rats were subjected to a severe burn injury. With the use of a sponge matrix model, the wound-healing parameters were evaluated. MATERIALS: A random sample of eight inbred albino Oxford rats per group were used in all experiments. INTERVENTIONS: Rats were subjected to a severe scald injury. Polyvinyl sponges were used as the wound-healing model. MAIN OUTCOME MEASURE: The obtained results implied that the wound-healing process is impaired after a severe burn injury. RESULTS: The wounds in these animals with burn injuries contained a lower number and an altered type of infiltrating cells with aberrant levels of cytokines, higher levels of interleukin-6, and lower levels of tumor necrosis factor and interleukin-1 in the fluids of the wounds. The parameters of healing (amounts of protein and collagen deposited at the site of the wound) were significantly lower in animals with burn injuries on days 7 and 14. CONCLUSION: The underlying mechanism of the impaired healing of a wound after burn injury could lie in the altered migration of inflammatory cells to the site of the wound and in the aberrant cytokine levels within the wound.