Peritoneal Cavity Of Mice Research Articles

The roles of different pathways in the release of cholesterol from macrophages

Cholesterol efflux occurs by different pathways, including transport mediated by specific proteins. We determined the effect of enriching cells with free cholesterol (FC) on the release of FC to human serum. Loading Fu5AH cells with FC had no effect on fractional efflux, whereas enriching mouse peritoneal macrophages (MPMs) resulted in a doubling of fractional efflux. Efflux from cholesterol-normal MPM and Fu5AH cells to 15 human sera correlated well with HDL parameters. However, these relationships were reduced or lost with cholesterol-loaded MPMs. Using macrophages from scavenger receptor class B type I (SR-BI)-, ABCA1-, and ABCG1-knockout mice, together with inhibitors of SR-BI- and ABCA1-mediated efflux, we were able to quantitate efflux upon loading macrophages with excess cholesterol and to establish the contributions of the various efflux pathways in cholesterol-normal and -enriched cells. The removal of ABCA1 had essentially no effect on the total efflux when cell cholesterol levels were normal. However, in cholesterol-enriched cells, the removal of ABCA1 reduced efflux by 50%. Approximately 20% of the efflux stimulated by FC-loading MPM is attributable to ABCG1. The SR-BI contribution to efflux was small. Another pathway that is present in all cells is aqueous diffusion. Our studies demonstrate that this mechanism is one of the major contributors to efflux, particularly in cholesterol-normal cells.

Cancer Immunotherapy Using Irradiated Tumor Cells Secreting Heat Shock Protein 70

Ovarian cancer is responsible for the highest mortality rate among patients with gynecologic malignancies. Therefore, there is an emerging need for innovative therapies for the control of advanced ovarian cancer. Immunotherapy has emerged as a potentially plausible approach for the control of ovarian cancer. In the current study, we have generated heat shock protein 70 (Hsp70)-secreting murine ovarian cancer cells that express luciferase (MOSEC/luc). Hsp70 has been shown to target and concentrate antigenic peptides in dendritic cells and is also able to activate dendritic cells. We characterized the antigen-specific immune response and the antitumor effect of the MOSEC/luc cells expressing Hsp70 using noninvasive luminescence images to measure the amount of ovarian tumors in the peritoneal cavity of mice. We found that mice challenged with MOSEC/luc cells expressing Hsp70 generate significant antigen-specific CD8+ T-cell immune responses. Furthermore, we also found that mice vaccinated with irradiated MOSEC/luc cells expressing Hsp70 generate significant therapeutic effect against MOSEC/luc cells. In addition, we have shown that CD8+, natural killer, and CD4+ cells are important for protective antitumor effect generated by irradiated tumor cell-based vaccines expressing Hsp70. Moreover, we also found that CD40 receptor is most important, followed by Toll-like receptor 4 receptor, for inhibiting in vivo tumor growth of the viable MOSEC/luc expressing Hsp70. Thus, the use of Hsp70-secreting ovarian tumor cells represents a potentially effective therapy for the control of lethal ovarian cancer.

Pro-inflammatory effect in mice of CvL, a lectin from the marine sponge Cliona varians

CvL, a lectin from the marine sponge Cliona varians agglutinated type A papainized erythrocytes and was strongly inhibited by d-galactose and sucrose. Models of leukocyte migration in vivo were used to study the inflammatory activity of CvL through of mouse paw oedema and peritonitis. Effect of CvL on peritoneal macrophage activation was analysed. Effects of corticoids and NSAIDS drugs were also evaluated on peritonitis stimulated by CvL. Results showed that mouse hind-paw oedema induced by subplantar injections of CvL was dose dependent until 50 μg/cavity. This CvL dose when administered into mouse peritoneal cavities induced maxima cell migration (9283 cells/μL) at 24 h after injection. This effect was preferentially inhibited by incubation of CvL with the carbohydrates d-galactose followed by sucrose. Pre-treatment of mice with 3% thioglycolate increases the peritoneal macrophage population 2.3 times, and enhanced the neutrophil migration after 24 h CvL injection (75.8%, p < 0.001) and no significant effect was observed in the presence of fMLP. Finally, pre-treatment of mice with dexamethasone (cytokine antagonist) decreased (65.6%, p < 0.001), diclofenac (non-selective NSAID) decreased (34.5%, p < 0.001) and Celecoxib (selective NSAID) had no effect on leukocyte migration after submission at peritonitis stimulated by CvL, respectively. Summarizing, data suggest that CvL shows pro-inflammatory activity, inducing neutrophil migration probably by pathway on resident macrophage activation and on chemotaxis mediated by cytokines.

In vivo imaging of hydrogen peroxide with chemiluminescent nanoparticles

The overproduction of hydrogen peroxide is implicated in the development of numerous diseases and there is currently great interest in developing contrast agents that can image hydrogen peroxide in vivo. In this report, we demonstrate that nanoparticles formulated from peroxalate esters and fluorescent dyes can image hydrogen peroxide in vivo with high specificity and sensitivity. The peroxalate nanoparticles image hydrogen peroxide by undergoing a three-component chemiluminescent reaction between hydrogen peroxide, peroxalate esters and fluorescent dyes. The peroxalate nanoparticles have several attractive properties for in vivo imaging, such as tunable wavelength emission (460-630 nm), nanomolar sensitivity for hydrogen peroxide and excellent specificity for hydrogen peroxide over other reactive oxygen species. The peroxalate nanoparticles were capable of imaging hydrogen peroxide in the peritoneal cavity of mice during a lipopolysaccharide-induced inflammatory response. We anticipate numerous applications of peroxalate nanoparticles for in vivo imaging of hydrogen peroxide, given their high specificity and sensitivity and deep-tissue-imaging capability.

Impact of Pseudomonas aeruginosa quorum sensing on biofilm persistence in an in vivo intraperitoneal foreign-body infection model

Pseudomonas aeruginosa is an opportunistic human pathogen that causes chronic biofilm-based infections in host organisms. P. aeruginosa employs quorum sensing (QS) to control expression of its virulence, and to establish and maintain chronic infections. Under such conditions, the biofilm mode of growth contributes significantly to P. aeruginosa tolerance to the action of the innate and adaptive defence system and numerous antibiotics. In the present study, an in vivo foreign-body infection model was established in the peritoneal cavity of mice. Experimental data showed that QS-deficient P. aeruginosa are cleared more rapidly from silicone implants as compared to their wild-type counterparts. Concurrently, treatment with the QS inhibitor furanone C-30 of mice harbouring implants colonized with the wild-type P. aeruginosa resulted in a significantly faster clearing of the implants as compared to the placebo-treated group. These results were obtained with both an inbred (BALB/c) and an outbred (NMRI) mouse strain. The present results support a model by which functional QS systems play a pivotal role in the ability of bacteria to resist clearing by the innate immune system and strongly suggest that the efficiency of the mouse innate defence against biofilm-forming P. aeruginosa is improved when the bacteria are treated with QS drugs that induce QS deficiency.

B‐1a cells are imprinted by the microenvironment in spleen and peritoneum

B-1a cells are found mainly in the peritoneal cavity of mice but are also present in the spleen. Gene expression profiling defined many genes differentially expressed in B-1a cells from these two sites. To see whether this gene expression pattern was imprinted by the particular microenvironment, peritoneal or spleen cells from recombinant L2 mice mainly consisting of B-1a cells were adoptively transferred into Rag1-/- mice. Re-isolated peritoneal and splenic B-1a cells were analyzed for expression of three indicator genes--vcam-1, adamdec1 and spi-c. The expression of these genes was up-regulated in splenic and down-regulated in peritoneal cells. This particular pattern was observed for peritoneal or splenic donor cells transferred either intraperitoneally or intravenously. Similar results were obtained when levels of surface IgM or frequencies of Mac-1+ B-1 cells were compared after transfer. This suggests that the environment induces the particular genetic program of B-1a cells and argues against an independent ontogeny.

Biochemical and biological characterization of the venoms of Bothriopsis bilineata and Bothriopsis taeniata (Serpentes: Viperidae)

Snake venom is a complex mixture containing diverse protein components with different structures and functions that are used for prey immobilization and death. Snake venoms from the family Viperidae cause pronounced local and systemic effects, such as pain, edema, hemorrhage and necrosis. Here, we investigated the enzymatic and biological activities of venoms from two Amazonian snakes, Bothriopsis bilineata and Bothriopsis taeniata. Both venoms presented high enzymatic activities for proteases kallikrein, thrombin and plasmin, low levels of trypsin, cathepsin C and leucine aminopeptidase activities, while lacked acetylcholinesterase activity. B. taeniata and B. bilineata crude venoms caused inflammation inducing neutrophil recruitment into peritoneal cavity of mice 4 h after injection. Neutrophil recruitment induced by B. taeniata venom was accompanied by hemorrhage. EDTA treatment profoundly impaired neutrophil recruitment, suggesting the involvement of a metalloproteinase on venoms-induced neutrophil recruitment. Pretreatment with dexamethasone and zileuton, a 5-lipoxygenase inhibitor, significantly reduced neutrophil migration, but indomethacin and montelukast, a cysteinyl leukotriene receptor antagonist, had no effect, suggesting the involvement of lipoxygenase-derived metabolites, probably LTB 4. Together, these results show that B. bilineata and B. taeniata venoms induce a marked inflammatory reaction, with leukocyte recruitment, and hemorrhage, which parallels to a high proteolytic activity found in these venoms.

Protective role of CCL6 during severe sepsis through interferon-γ generation and interferon-producing killer dendritic cells recruitment (44.18)

Abstract Our group has previously demonstrated that CCL6 enhanced antimicrobial immunity during sepsis through an unknown mechanism. The goal of this study was to investigate the mechanism involved in the protective role of CCL6 during the severe sepsis. C57BL/6 transgenically overexpressing CCL6 (Tg) in the lung and wild type (WT) mice were submitted to cecal ligation and puncture (CLP) and sham operation, and survival was evaluated for up to 7 days post-CLP. Cells from peritoneal cavity (PC) were obtained 3 days after surgery. The CCL6 Tg group exhibited greater levels of CCL6 in the lung and PC when compared to WT group after sham and CLP surgery. While CCL6 Tg mice presented 90% of survival at day 7 only 20% of WT mice survived. High levels of interferon-γ (IFN-γ) were detected in the PC of CCL6 Tg mice at 3 days post-CLP. Also, cells obtained from PC of these mice produced significantly levels of IFN-γ. When CCL6 Tg mice received anti-IFN-γ prior CLP, only 20% were alive. At 3 days after sham and CLP operation, the number of natural killer (NK) cells and interferon-producing killer dendritic cells (IKDCs) was increased in the peritoneal cavity of CCL6 Tg mice when compared to WT mice. These data suggest that the protective role of CCL6 may be due to its ability to contain the consequences of an inappropriate type 2-cytokine response during anti-pathogen responses. CCL6 may achieve this through promotion of IFN-γ and NK cells and IKDCs recruitment.

TLR3 and TLR9 mRNA expression is impaired in macrophages from severely burned mice (44.31)

Abstract Classically activated Mϕ (CAMϕ) are not generated in mice with severe burn injuries even when they are stimulated with a mixture of poly I:C and CpG DNA (well-known inducers for CAMϕ). To investigate why the Mϕ conversion from burn mouse-derived Mϕ to CAMϕ was not induced after stimulation with a mixture of poly I:C and CpG DNA, the expression of receptors for poly I:C (TLR3) and CpG DNA (TLR9) in burn mouse-derived Mϕ were examined. BALB/c mice exposed to a flame burn injury (3rd degree, 25% TBSA burns) were used for these studies. Mϕ were prepared from the peritoneal cavities of mice 6, 24, 48, 120 and 168 hrs after burn injury using magnetic beads coated with anti-F4/80 mAb. Peritoneal Mϕ from unstimulated normal mice were utilized as a control. Then, Mϕ preparations obtained were analyzed for TLR3 and TLR9 mRNA expression using RT-PCR. In the results, TLR3 and TLR9 mRNAs were shown to be expressed by Mϕ from normal mice. However, TLR3 mRNA expression was not demonstrated in Mϕ from mice 6 to 168 hrs after burn injury. TLR9 mRNA expression was strongly impaired in Mϕ from mice 6 hrs after burn injury, and then it gradually recovered until 120 hrs after burn injury. These results indicate that burn mouse-derived Mϕ are shown to not be a carrier of TLR3 and TLR9. The unresponsiveness of burn mouse-derived Mϕ to the CAMϕ inducers may be related to the impaired expression of TLR3 and TLR9 that are receptors for poly I:C and CpG DNA, respectively. This study was supported by SHC NA #8550.

Monitoring of dissolved oxygen and cellular bioenergetics within a pancreatic substitute

This work investigated the use of nuclear magnetic resonance (NMR) spectroscopy in combination with a mathematical model of an encapsulated cell system as a method for rapidly assessing the status of a pancreatic substitute. To validate this method, an in vitro experiment was performed in which the encapsulated cells were perfused in an NMR-compatible system and the dissolved oxygen (DO) concentration of the perfusing medium was lowered from 0.20 to 0.05 mM, then returned to 0.20 mM in a stepwise fashion. The cellular metabolic activity and bioenergetics were evaluated by measuring the oxygen consumption rate (via DO sensors) and nucleotide triphosphate levels (via (31)P NMR). By incorporating a perfluorocarbon emulsion into the alginate beads, the cellular oxygenation state was monitored by measuring the average intrabead DO (AIDO) concentration by (19)F NMR. The in vitro measurements were then compared with model predictions based on the measured external DO concentration and time. Model-predicted cell growth and AIDO closely matched the experimentally acquired data. As the DO concentrations both external to and within the pancreatic substitute are needed to apply this methodology in vivo, the feasibility of measuring the DO concentration from two distinct bead populations implanted in the peritoneal cavity of mice was established. It is concluded that PFC incorporation and (19)F NMR measurements, in combination with a mechanistic model of the encapsulated system, allow the tracking of the state of a pancreatic substitute in vitro and potentially in vivo.

산삼과 산양삼 추출물의 항암 및 항산화 효능

Objectives : The aim of this study was to verify anti-cancer and anti-oxidant efficacies of Korean wild ginseng and cultivated wild ginseng of Korea and China. Methods : For the measurement of anti-oxidation, SOD-like activity was evaluated using xanthine oxidase reduction method under in vitro environment. Subcutaneous and abdominal cancer were induced using CT-26 human colon cancer cells for the measurement of growth inhibition of cancer cells and differences in survival rate. Results : 1. Measurement of anti-oxidant activity of ginseng, Chinese and Korean cultivated wild ginseng, and natural wild ginseng samples showed concentration dependent anti-oxidant activity in HX/XOD system. Anti-oxidant activity showed drastic increase at 1mg/ml in all samples. 2. For the evaluation of growth inhibition of cancer cells after hypodermic implantation of CT-26 cancer cells in the peritoneal cavity of mice, Chinese and Korean cultivated wild ginseng and natural wild ginseng groups showed significant inhibition of tumor growth from the 12th day compared to the control group. Similar inhibitory effects were also shown on the 15th and 18th days. But there was no significant difference between the experiment groups. 3. For the observation of increase in survival rate of the natural wild ginseng group, CT-26 cancer cells were implanted in the peritoneal cavity of mice.

Inhibition of peritoneal dissemination of tumor cells by cationized catalase in mice

To inhibit peritoneal dissemination of tumor cells by destroying hydrogen peroxide, ethylenediamine-conjugated catalase (ED-catalase), a cationized derivative, was injected into the peritoneal cavity of mice. ED-catalase had about a 6-fold longer retention time within the cavity than unmodified catalase. Peritoneal dissemination was evaluated after intraperitoneal inoculation of B16-BL6/Luc, a melanoma clone stably expressing firefly luciferase, by measuring luciferase activity. An intraperitoneal injection of ED-catalase just before tumor inoculation significantly reduced the number of tumor cells in peritoneal organs. Catalase was less effective, confirming the importance of the retention of the enzyme within the cavity for the inhibition. ED-catalase injected 3 days after tumor inoculation was also effective in inhibiting tumor growth. A real-time quantitative PCR analysis revealed that ED-catalase significantly suppressed the expression of intercellular adhesion molecule-1. Daily dosing of ED-catalase for 7 days significantly prolonged the survival of tumor-bearing mice. These findings indicate that ED-catalase, which is retained for a long time within the peritoneal cavity, is highly effective in inhibiting the adhesion and proliferation of peritoneally disseminated tumor cells, and in increasing the survival of tumor-bearing mice.

Antibody response in mice infected with Mesocestoides vogae (syn. Mesocestoides corti) tetrathyridia after treatment with praziquantel and liposomised glucan

The therapeutic effect of praziquantel (PZQ) involves synergy with the humoral immune response during helminth infections, which is modulated by parasitic antigens. During experimental murine infections with the larval stage of cestoda Mesocestoides vogae (syn. M. corti), dynamic changes in the IgG and IgM antibody serum levels to both soluble somatic and secretory larval antigens were investigated after administration of PZQ alone and after its co-administration with the immunomodulator (l-->3)-beta-D-glucan entrapped in liposomes (lip.glucan). During the 2 weeks of follow-up after termination of therapy, specific IgG and IgM serum levels to the somatic antigens (enzyme-linked immunosorbent assay test) significantly decreased, whereas concentrations of the antibodies to the secretory antigens moderately increased, both in comparison with the control. Moreover, the number of immunogenic larval antigens (analysed by Western blot) was higher after combined therapy in comparison with single drug administration, which correlated with the intensity of reduction of the larval counts in the liver and peritoneal cavity of mice. Our data showed that administration of PZQ alone and in combination with lip.glucan resulted in marked changes in the dynamics of IgG and IgM antibodies to the somatic larval antigens, which were probably induced by the newly exposed antigens. In this respect, glucan can enhance chemotherapeutic activity of PZQ against larval cestodes by means of stimulation of the macrophage/monocyte effector functions, which seemed to contribute to the more intense larval damage.

Dual Assemblies of an Activating Immune Receptor, MAIR-II, with ITAM-Bearing Adapters DAP12 and FcRγ Chain on Peritoneal Macrophages

Certain activating immune receptors expressed on myeloid cells noncovalently associate with either DAP12 or FcepsilonRIgamma (FcRgamma chain), the ITAM-bearing transmembrane adapter proteins. An activating receptor, myeloid-associated Ig-like receptor (MAIR) II, is expressed on a subset of B cells and macrophages in the spleen and peritoneal cavity of mice and associates with DAP12 in these cells. However, we demonstrate here that cross-linking MAIR-II with mAb induced secretion of a significant amount of the inflammatory cytokines TNF-alpha and IL-6 from DAP12(-/-) as well as wild-type (WT) peritoneal macrophages. We show that MAIR-II associates with not only DAP12 but also FcRgamma chain homodimers in peritoneal macrophages. LPS enhanced the FcRgamma chain expression and FcRgamma chain-dependent cell surface expression of MAIR-II and had additive effects on MAIR-II-mediated inflammatory cytokine secretion from peritoneal macrophages. The lysine residue in the transmembrane region of MAIR-II was involved in the association with FcRgamma chain as well as DAP12. Our findings present the first case of an activating receptor that uses either DAP12 or FcRgamma chain as a signaling adapter. The FcRgamma chain may provide cooperation with and/or compensation for DAP12 in MAIR-II-mediated inflammatory responses by peritoneal macrophages.

Optimization of microencapsulated recombinant CHO cell growth, endostatin production, and stability of microcapsulein vivo

Microencapsulation of recombinant cells secreting endostatin offers a promising approach to tumor gene therapy in which therapeutic protein is delivered in a sustainable and long-term fashion by encapsulated recombinant cells. However, the studies of cell growth and protein production in vivo are very limited. In this study, the effects of microencapsulation parameters on in vivo cell growth, endostatin production, and microcapsule stability after implantation in the peritoneal cavity of mice were for the first time investigated. Microcapsules with liquid core reached higher cell density and endostatin production at day 18 than microcapsules with solid core. There was no significant difference in stability whether the core of the microcapsule was solid or liquid. Decrease in microcapsule size increased the stability of microcapsule. The microcapsules kept intact in the peritoneal cavity of mice after 36 days of implantation when the microcapsules size was 240 microm in diameter, which gave rise to high endostatin production as well. The optimized microencapsulation conditions for in vivo implantation are liquid core and 240 microm in diameter. This study provides useful information for antiangiogenic gene therapy to tumors using microencapsulated recombinant cells.

Reduced Lipopolysaccharide (LPS)-Induced Nitric Oxide Production in Peritoneal Macrophages and Inhibited LPS-Induced Lethal Shock in Mice by a Sugar Cane (Saccharum officinarumL.) Extract

A sugar cane extract (SCE) has been found to have an immunostimulating effect in several animals. Lipopolysaccharide (LPS) is known to induce endotoxin shock via the production of inflammatory modulators such as tumor necrosis factor (TNF)-alpha and nitric oxide (NO). We examined in the present study the effects of SCE on the TNF-alpha and NO production in LPS-stimulated mice peritoneal cells and the endotoxin shock in mice. The supplementation of SCE to peritoneal macrophages cultured with LPS resulted in a significant decrease in NO production. All the mice injected intraperitoneally with LPS and D-galactosamine (LPS+GalN) died within 24 h. However, a peritoneal injection, but no intravenous or oral administration, of SCE (500-1,000 mg/kg) at 3 to 48 h before the LPS+GalN-challenge resulted in a significantly improved survival rate. These results suggest that SCE had a protective effect on LPS-induced endotoxin shock via one of possible mechanisms involving the suppression of NO production in the mouse peritoneal cavity.

Disproportionally low clearance of macromolecules from the plasma to the peritoneal cavity in a mouse model of peritoneal dialysis

This study was performed to establish a model for quantitative measurements of a number of basic peritoneal transport parameters, particularly transperitoneal clearances (Cl) of macromolecules, during mouse peritoneal dialysis. Mice were anaesthetized using 3% isofluorane inhalation anaesthesia. The right jugular vein and the left femoral artery were cannulated for infusion and sampling purposes and for registration of (mean) arterial blood pressure. Access to the peritoneal cavity occurred via a thin abdominal catheter (Ø 0.7 mm). About 2.5 ml of either 4% (n = 9) or 1.5% (n = 5) glucose containing PD-fluid were instilled intraperitoneally (i.p.). Dialysate volume was followed vs time using i.p. RISA ((125)I human serum albumin) as a volume marker, after correcting for RISA mass disappearance from the peritoneum, assessed separately (n = 11). Microsampling (10 microl) of plasma and dialysate was performed for determinations of glucose, haematocrit, radioactivity (RISA and (51)Cr-EDTA) and Ficoll. The i.p. volume vs time curves [V(D)(t)] were, after scaling, similar to those observed in humans (and in rats). Clearance of RISA out of the peritoneal cavity (Cl(out)) was 9.33 +/- 0.83 microl/min and the clearance of RISA to plasma (Cl-->P) and the RISA clearance to the peritoneal cavity (Cl-->D) were 1.49 +/- 0.13 and 0.084 +/- 0.008 microl/min, respectively. The peritoneal transport coefficients for (51)Cr-EDTA and glucose, as well as Cl(out) and Cl-->P, were 13-17% of those previously assessed in 300 g rats, whereas Cl-->D was only approximately 2% of that in rat. All peritoneal transport parameters measured, except Cl-->D, scaled very well to the corresponding human data. The mechanisms of the disproportionally low clearance of macromolecules from the plasma to the peritoneal cavity in mice remain elusive and warrant further study.

Vascular endothelial growth factor and matrix metalloproteinase-2 expedite formation of endometriosis in the early stage ICR mouse model

To establish a mouse model for endometriosis and to evaluate roles of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) in the formation of disease. Experimental laboratory study. A women's hospital in China. Ten women with endometriosis and 10 control women, as well as ICR mice. Endometrial fragments were transplanted in the peritoneal cavities of mice at minilaparotomy. Transplants were observed and then removed for the assessment of morphology and immunohistochemical staining of VEGF and MMP-2. Observation of transplants, expression of VEGF and MMP-2. On days 1 and 2, glandular and stromal cells were viable at the margins of transplants. On day 3, the transplants were surrounded by mesothelial cells, and the endometrial glands and stromal cells were clearly viable at the interface. The scores of VEGF and MMP-2 of viable glandular cells of transplants were increased compared with the ones before transplantation. The scores of VEGF and MMP-2 of transplants from women with endometriosis were higher than those of control women. Endometrial transplants from the patients with endometriosis express more VEGF and MMP-2 than endometrium in control women, suggesting that VEGF and MMP-2 may expedite the formation of endometriosis in its early stage.

Neutrophil migration in mice induced by a mannose-binding lectin isolated from Annona coriacea seeds

A novel 14-kDa lectin from Annona coriacea seeds (ACLEC) with hemagglutinating activity on erythrocytes has been recently described. Since plant lectins are known to present inflammatory activity, this study aimed to investigate the leukocyte migration induced by ACLEC, and inflammatory mediators involved in this phenomenon. Male Swiss mice were intraperitoneally injected with ACLEC (3–100 μg/cavity), and at 4–96 h thereafter the leukocyte counts in peritoneal lavage fluid were evaluated. ACLEC induced a dose-dependent neutrophil accumulation, reaching maximal responses at 16 h after injection (approximately 40-fold increase for 30 μg/cavity). Significant accumulation of mononuclear cells was observed at 72 h (2.7-fold increase). The carbohydrate mannose nearly abolished the neutrophil influx, whereas sucrose, glucose and galactose had no effect. Dexamethasone, the cyclooxygenase-2 (COX-2) inhibitor celecoxib and the Platelet activating factor (PAF) receptor antagonist PCA4248 significantly reduced ACLEC-induced neutrophil influx. The tachykinin NK 1 antagonist SR140333, the tachykinin NK 2 antagonist SR48968, the non-selective NO inhibitor L-NAME, the selective inducible NOS inhibitor aminoguanidine and the lypoxygenase inhibitor AA861 all failed to modify the ACLEC-induced responses. In conclusion, ACLEC is able to attract neutrophils into the mice peritoneal cavity by mechanisms involving interactions of the lectin with cell-specific mannose recognition, leading to the release of COX-2-derived mediators and PAF.

Feasibility of simple chitosan sheet as drug delivery carrier

Chitosan, a biodegradable and biocompatible polysaccharide, is a potentially useful material in various fields. We developed a simple chitosan sheet and examined the possibility of using an adriamycin-containing chitosan sheet as a drug carrier for controlled release. To prepare a carrier consisting only of chitosan, a chitosan suspension was subjected to acid-alkaline treatment, mixed with adriamycin, frozen and freeze-dried. The adriamycin-containing chitosan sheet was inserted into the peritoneal cavity of mice in order to investigate its biodegradation. The appearance of decomposition of chitosan was observed using scanning electron microscopy, and adriamycin in urine and liver was detected for 1 and 2 weeks, respectively. Adriamycin metabolites were detected in plasma for 2 weeks. Furthermore, adriamycin remained in the chitosan sheet without being metabolized after 2 months. These results suggested that the chitosan sheet prepared in this study might improve therapeutic efficacy in topical lesions as a carrier of sustained-release drugs.