Functional analysis of differences in transcriptional activity conferred by genetic variants in the 5' flanking region of the IL12RB2 gene.

Interleukin 12 receptor ß chain (IL12RB2) is a crucial regulatory factor involved in cell-mediated immune responses, and genetic variants of the gene encoding IL12RB2 are associated with susceptibility to various immune-related diseases. We previously demonstrated that haplotypes with single nucleotide polymorphisms (SNPs) in the 5' flanking region of IL12RB2, including -1035A>G (rs3762315) and -1023A>G (rs3762316), affect the expression of IL12RB2, thereby altering susceptibility to leprosy and periodontal diseases. In the present study, we identified transcription factors associated with the haplotype-specific transcriptional activity of IL12RB2 in T cells and NK cells. The -1023G polymorphism was found to create a consensus binding site for the transcription factor activating protein (AP)-1, and enzyme-linked immunosorbent assay (ELISA)-based binding assays showed that these SNPs enhanced AP-1 binding to this region. In reporter assays, suppression of JunB expression using siRNA eliminated differences in the -1035G/-1023G and -1035A/-1023A regions containing IL12RB2 promoter activity in Jurkat T cells and NK3.3 cells. These results suggested that the -1035/-1023 polymorphisms created differential binding affinities for JunB that could lead to differential IL12RB2 expression. Moreover, the -1035G and -1035A alleles formed binding sites for GATA-3 and myocyte enhancer factor-2 (MEF-2), respectively. Our data indicated that in addition to JunB, the SNP at -1035/-1023 influenced GATA-3 and MEF-2 binding affinity, potentially altering IL12RB2 transcriptional activity. These findings confirm the effects of rs3762315 and rs3762316 on IL12RB2 transcription. These genetic variants may alter cellular activation of T cells and NK cells and modify cell-mediated immune responses.

Expression of interleukin-34 and colony stimulating factor-1 in the stimulated periodontal ligament cells with tumor necrosis factor-α.

Tumor necrosis factor-α (TNF-α) directly and indirectly plays a crucial role in osteoclastogenesis. However, the indirect effects of TNF-α on colony-stimulating factor-1 receptor (CSF-1R)-mediated osteoclastogenesis achieved via periodontal ligament (PDL) cells are not fully understood. We herein examined the potency of osteoclast differentiation and maturation induced by fivefold supernatants in the stimulated human PDL cells with a physiologically high concentration (10 ng/mL) of recombinant TNF-α to human peripheral blood monocytes/macrophages in the simultaneous presence of the receptor activator of nuclear factor kappa-B ligand. The number of tartrate-resistant acid phosphatase-positive cells with multiple nuclei, but not those with a single nucleus, was decreased by approximately 50% by neutralization with rabbit IgG against either interleukin-34 (IL-34) or CSF-1. Small and large amounts of IL34 and CSF1 transcripts were measured in the stimulated PDL cells using real-time polymerase chain reaction. The corresponding amounts of proteins to IL34 and CSF1 transcripts were observed in the stimulated PDL cells on immunohistochemical staining or Western blotting. Moreover, 0.13 ng/mL of IL-34 and 5.0 ng/mL of CSF-1 were measured in the supernatants of the stimulated PDL cells using an enzyme-linked immunosorbent assay. IL-34 derived from the stimulated PDL cells with TNF-α appeared to synergistically function with CSF-1 in the CSF-1R-mediated maturation of osteoclastogenesis.

Estrogen decreases the expression of claudin-5 in vascular endothelial cells in the murine uterus.

Vascular endothelial (VE)-cadherin and claudin-5 are major components of the adherens and tight junctions of vascular endothelial cells, respectively, and decreases in their expression are associated with increases in endothelial paracellular permeability. In the uterus, estrogen induces endometrial edema. However, the in vivo effect of estrogen on endothelial paracellular permeability is unknown. Therefore, we studied the expression of VE-cadherin and claudin-5 in vascular endothelial cells in murine uteri stimulated by estrogen or progesterone. Ovariectomized mature mice were injected with estradiol-17ß (1 µg/mouse) or progesterone (1 mg/mouse) at intervals of 24 hours for 6 days. The frozen transverse sections of the uteri of these mice and untreated mice were stained for CD31 (vascular endothelial cell marker) plus VE-cadherin or claudin-5 using a double-immunofluorescence method. Then, the percentages of VE-cadherin- or claudin-5-positive vessels among CD31-positive vessels were examined in the uterine endometria. VE-cadherin and claudin-5 were expressed in most CD31-positive vessels in the endometria of the untreated mice. Progesterone did not affect the expression of both VE-cadherin and claudin-5 and estradiol-17ß also did not affect the VE-cadherin expression, but estradiol-17ß significantly decreased the claudin-5 expression. This decreasing effect of estradiol-17ß was detected from 24 hours later when the water content per a uterus significantly increased. The present study indicates that estrogen, but not progesterone, decreases the expression of claudin-5 in vascular endothelial cells in the murine uterine endometrium from 24 hours later, suggesting that the decrease in the claudin-5 expression contributes to the endometrial edema late after the estrogen stimulation.

Decreased expression of VE-cadherin and claudin-5 and increased phosphorylation of VE-cadherin in vascular endothelium in nasal polyps.

VE-cadherin and claudin-5 are major components of adherens and tight junctions of vascular endothelial cells and a decrease in their expression and an increase in the tyrosine-phosphorylation of VE-cadherin are associated with an increase in endothelial paracellular permeability. To clarify the mechanism underlying the development of edema in nasal polyps, we studied these molecules in polyp microvessels. Normal inferior turbinate mucosal tissues and nasal polyps from patients treated with or without glucocorticoid were stained for VE-cadherin or claudin-5 and CD31 by a double-immunofluorescence method and the immunofluorescence intensities were graded 1-3 with increasing intensity. To correct for differences in fluorescence intensity attributable to a different endothelial area being exposed in a section or to the thickness of a section, the relative immunofluorescence intensity was estimated by dividing the grade of VE-cadherin or claudin-5 by that of CD31 in each microvessel. Tyrosine-phosphorylation of VE-cadherin was examined by Western blot analysis. The relative intensities of VE-cadherin and claudin-5 in the CD31-positive microvessels significantly decreased in the following order; inferior turbinate mucosa, treated polyps and untreated polyps. The ratio of tyrosine-phosphorylated VE-cadherin to VE-cadherin was significantly higher in untreated polyps than in the inferior turbinate mucosa and treated polyps, between which no significant difference in the ratio was seen. Thus, in nasal polyps, the barrier function of endothelial adherens and tight junctions is weakened, although glucocorticoid treatment improves this weakened barrier function.

The promotional effect of IL-22 on mineralization activity of periodontal ligament cells.

OBJECTIVES: Interleukin (IL)-22 acts on non-immune cells to induce anti-microbial responses, protection from tissue damage, and enhance cell regeneration. However, little is known about the involvement of IL-22 in periodontal biology. This study investigated the biological effects of IL-22 on periodontal ligament (PDL) cells as part of studies to assess the involvement of IL-22 in periodontal disease. MATERIALS AND METHODS: Gene expression levels of IL-22 and its receptors in PDL cells and gingival tissue samples were evaluated by real-time PCR. Proliferative responses and mineralized-matrix forming activities of PDL cells were examined in the presence and absence of IL-22. RESULTS: In contrast to the expression of IL-22 receptors detected in PDL tissues and their cell lines, gingival tissues showed modest or no gene expressions of IL-22. The production of several cytokines including IL-11, IL-8 and CCL2 was upregulated by IL-22 treatment of PDL cells in a dose-dependent manner. IL-22 treatment had no effect on the proliferative response in PDL cells. Meanwhile, IL-22 precipitated mineralized nodule formation and induced gene expressions of RUNX2, MSX2 and osteocalcin in PDL cells, suggesting that IL-22 enhances the mineralized matrix-forming activities of PDL cells. CONCLUSION: IL-22 has the potential to promote mineralizing activity in PDL cells and to develop appropriate regenerative therapy.

Expression of both hepatocellular carcinoma and cholangiocarcinoma phenotypes in hepatocellular carcinoma and cholangiocarcinoma components in combined hepatocellular and cholangiocarcinoma.

Expression of phenotype markers of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) in HCC and CC components of 20 combined hepatocellular and cholangiocarcinomas (CHCs) of the liver was investigated immunohistochemically. Both HCC and CC components of all CHCs expressed at least one of the CC phenotype markers [cytokeratin (CK)-7, CK-19, and carbohydrate (CA) 19-9]. HCC components in 90% of CHCs and CC components in 95% of CHCs expressed at least one of these CC phenotype markers in more than 40% of cancer cells. HCC components in all CHCs expressed at least one of the HCC phenotype markers [hepatocyte antigen (HA), α-fetoprotein (AFP), and canalicular carcinoembryonic antigen]. HCC components in 90% of CHCs and CC components in 75% of CHCs expressed HA, AFP, or both. HCC components in 75% of CHCs and CC components in 60% of CHCs expressed HA, AFP, or both in more than 10% of cancer cells. The present results show that both HCC and CC components of most of the CHCs expressed both HCC and CC phenotypes, supporting the hypothesis that CHC originates from a hepatic progenitor cell capable of differentiating into hepatocytes and cholangiocytes.

Fibroblasts stimulated via HLA-II molecules produce prostaglandin E2 and regulate cytokine production from helper T cells.

Fibroblasts act as important immune regulatory cells via their ability to cross-talk with T cells accumulating in lesions. Our previous study showed that fibroblasts produce several cytokines and chemokines by crosslinking HLA class II (HLA-II) molecules with monoclonal antibodies or by making T-cell receptor-peptide-HLA complexes. It is thus conceivable that the interaction of T cells and fibroblasts via HLA-II affects fibroblast responses to stimuli. This study used human gingival fibroblasts (HGF) to investigate possible effects of these fibroblast-derived soluble factors on the differentiation of naïve T cells and on the subsequent fibroblast responses. After mixed lymphocyte reaction culture between naïve T cells and allogeneic dendritic cells in the presence of culture supernatant from HGF stimulated via HLA-DQ molecules (DQ-sup), but not via DR, T cells exhibited a Th2-shifted phenotype, thereby producing quantitatively more IL-13 and IL-5 compared with interferon-γ. Astonishingly, analyses to identify possible factors affecting the Th2 polarization secreted from HLA-II-stimulated HGF, prostaglandin E2, was detected only in DQ-sup. The Th2 polarization of naïve T cells was blocked in the presence of supernatants from indomethacin-treated HGF with HLA-DQ stimulation. In addition, we found that the culture supernatants of Th cells activated following mixed lymphocyte reaction culture in the presence of DQ-sup had the potential to induce gene expression of type I and III collagens in HGF. These results suggested that fibroblasts stimulated via HLA-DQ molecules promote Th2 polarization in Th-cell responses and showed the counter activation of collagen synthesis, implicating orchestrated responses among these cells in the fibrosis of chronic inflammatory lesions.

Immunotherapy with interleukin-18 in combination with preoperative chemotherapy with ifosfamide effectively inhibits postoperative progression of pulmonary metastases in a mouse osteosarcoma model.

The effect of immunotherapy with interleukin-18 (IL-18) in combination with preoperative chemotherapy on the postoperative progression of pulmonary metastasis was examined using a spontaneous pulmonary metastasis model of mouse osteosarcoma. Mice were inoculated subcutaneously with highly metastatic murine osteosarcoma cells (LM8) and then underwent chemotherapy with ifosfamide (30 or 60 mg/kg body weight, days 14-16), immunotherapy with IL-18 (2 microg/mouse, days 18-24) or combined immunotherapy and chemotherapy. Tumors developed in mice were excised 21 days after cell inoculation when microscopic but not macroscopic pulmonary metastasis was observed in mice. Three weeks after the excision of the tumors, macroscopic pulmonary metastasis was observed on the surface of the lung. Administration of ifosfamide or IL-18 alone decreased the number of macroscopic pulmonary metastases, and combined administration of ifosfamide and IL-18 resulted in much greater inhibition of pulmonary metastasis. These results suggest that immunotherapy in combination with preoperative chemotherapy is highly effective in suppressing postoperative progression of pulmonary metastasis.

Role of human non-invariant NKT lymphocytes in the maintenance of type 2 T helper environment during pregnancy.

The molecular and cellular mechanisms that generate the T(h)2 cytokine environment necessary for the maintenance of pregnancy are still not fully understood. We herein show that the human decidua is highly enriched for TCR alpha beta(+)CD161(+) NKT cells. They express non-invariant antigen receptors encoded by diverse TCRV alpha- and V beta-chain gene segments, thereby referred to as non-invariant NKT (non-iNKT) cells. In spite of their diverse TCR expression, they do not recognize fetal allo-antigens but specifically responded to CD1d-transfected cell lines. In contrast to the peripheral blood non-iNKT cells, the decidua-residing non-iNKT cells had a marked T(h)2 bias. In addition, they suppress the mixed leukocyte reaction directed against the paternal antigens. The T(h)2 cytokines have been known to stimulate trophoblast outgrowth and invasion. Thereby, the non-iNKT cells residing in the decidual tissue may have a functionally important interaction with the villous and extravillous trophoblast cells expressing CD1d and may therefore play a pivotal role in successful pregnancy by inhibiting fetal rejection and enhancing placental growth. These findings may reflect one mechanism that is an essential component for the T(h)2 environment necessary for the maintenance of pregnancy.

An unusual autopsy case of pyogenic liver abscess caused by periodontal bacteria.

Pyogenic liver abscess (PLA) formation is thought to originate from the transmission of infection via three major routes including the biliary tract, portal vein and hepatic artery. However, about 50% of PLA cases are considered to be cryptogenic. Here we report an unusual autopsy case of PLA associated with periodontopathic bacterial infection. A 59-year-old female suddenly developed cardiopulmonary arrest and died. Despite macroscopic and microscopic examinations, the infectious routes and source of infection were unidentified, and the case appeared to be cryptogenic. Since this patient had suffered severe periodontitis for a long period of time, we investigated the involvement of periodontal infection in PLA formation by performing immunohistochemical analyses. We identified several periodontopathic bacterial species in the PLA of this patient, including Fusobacterium nucleatum, Treponema denticola, Prevotella intermedia and Porphyromonas gingivalis. Thus, we demonstrate here that periodontal infection is a potential source of infection in the formation of PLA.

Immunohistochemical analyses of E-cadherin, beta-catenin, CD44s, and CD44v6 expressions, and Ki-67 labeling index in intraductal papillary mucinous neoplasms of the pancreas and associated invasive carcinomas.

We examined the expressions of adhesion molecules (E-cadherin, beta-catenin, CD44s, and CD44v6) and Ki-67 labeling index (Ki-67 LI) in low- and moderate-grade dysplasia and invasive carcinoma components in ten noninvasive intraductal papillary mucinous neoplasms (IPMNs) of the pancreas and eight invasive carcinomas associated with IPMNs of the pancreas using immunohistochemical methods. There was no significant difference in regard to the proportion of components expressing either E-cadherin or beta-catenin in more than 70% of the tumor cells between the low- and moderate-grade dysplasia components. In contrast, the proportion of those in invasive carcinoma components was significantly lower than in low- or moderate-grade dysplasia components. Also, there was no significant difference in the proportion of components expressing CD44s or CD44v6 in more than 5% of tumor cells among low-grade dysplasia, moderate-grade dysplasia, and invasive carcinoma components. In contrast, the Ki-67 LI values increased in the order of low-grade dysplasia, moderate-grade dysplasia, and invasive carcinoma components, with significant differences among them. The present results indicate that carcinoma components are associated with a decrease in tumor cells expressing E-cadherin and beta-catenin and have the highest proliferative activity.

Enhanced suppression of pulmonary metastasis of malignant melanoma cells by combined administration of alpha-galactosylceramide and interleukin-18.

alpha-Galactosylceramide (alpha-GalCer) shows antitumor effects by activating natural killer (NK) cells indirectly through stimulation of the secretion of cytokines by NKT cells, whereas interleukin (IL)-18 shows antitumor effects by activating NK cells directly. In the present study, we examined the antitumor effect of the combined administration of alpha-GalCer and IL-18. An injection of NK cell-sensitive mouse B16 melanoma cells into a mouse tail vein produced pulmonary metastasis. The daily administration of alpha-GalCer or IL-18 alone for 4 days starting 1 day after the injection of B16 melanoma cells markedly suppressed the number of pulmonary metastatic foci, and their combined administration enhanced the antitumor effect compared with single administration. The antitumor effect of their combined administration was completely abolished by treatment of mice with anti-asialo GM1 serum, which depletes NK cells but not NKT cells. Combined administration of alpha-GalCer and IL-18 enhanced the cytotoxicity of NK cells and increased the number of NK cells in the lung. Analysis of NKT cell-dependent and NK cell-independent secretion of cytokines, to which NK cells can respond, showed that the administration of alpha-GalCer increased the secretion of IL-2, IL-4, interferon-gamma, IL-12, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha, and IL-10, and the combined administration of alpha-GalCer and IL-18 enhanced the secretion of IL-2, IL-4, interferon-gamma, and granulocyte-macrophage colony-stimulating factor further but only slightly. These results show that IL-18 in combination with alpha-GalCer exerts an antitumor effect on NK cell-sensitive tumors primarily by the direct stimulation of NK cells by IL-18 and the indirect stimulation of NK cells by alpha-GalCer through its activation of NKT cells.

Transdifferentiation into biliary ductular cells of hepatocytes transplanted into the spleen.

AIMS: Transplantation of rat hepatocytes into the syngeneic rat spleen results in the appearance of cytokeratin (CK)7 and CK19 positive biliary cells that form ductules. We examined whether hepatocytes are the origin of these biliary ductular cells. METHODS: We transplanted rat dipeptidyl peptidase IV (DPPIV) positive hepatocytes into the liver of retrorsine-treated and partially hepatectomised DPPIV negative rats, which resulted in proliferation of DPPIV positive hepatocytes in the liver. Two months later, hepatocytes were prepared from chimaeric livers of these rats and transplanted into the spleen of DPPIV negative rats. Four weeks later, the expression of DPPIV in CK7 positive ductules in the spleen was examined by immunofluorescent double-staining. RESULTS: In the spleen of DPPIV negative rats transplanted with hepatocytes prepared from the chimaeric livers, DPPIV was found to be expressed in some CK7 positive biliary ductules where only a fraction of cells expressed DPPIV, whereas in the spleen of DPPIV negative rats transplanted with hepatocytes from livers of DPPIV positive rats, DPPIV was expressed in all CK7 positive biliary ductules. CONCLUSION: The present study indicates that hepatocytes transplanted into the spleen could transdifferentiate into biliary cells that aggregate to form ductular structures.

Polymorphisms in the 5' flanking region of IL12RB2 are associated with susceptibility to periodontal diseases in the Japanese population.

OBJECTIVES: The expression of interleukin (IL)-12Rbeta2 molecule is a crucial regulatory factor in the T-helper type (Th) 1 differentiation of T cells. To elucidate the role of the cell-mediated immune (CMI) response in the pathogenesis of periodontitis, Japanese periodontal patients were subjected to single nucleotide polymorphism (SNP) analyses of the 5' flanking region of IL12RB2, whose variants are frequently detected in lepromatous leprosy patients, in which the very weak cellular immune response is caused by low expression of IL-12Rbeta2. MATERIAL AND METHODS: The gene polymorphisms of the 5' flanking region of IL12RB2 were examined in subjects with several types of periodontal disease and in healthy controls. Serum immunoglobulin (Ig) G antibody titres against periodontopathic bacteria were measured and compared in periodontal patients with and without variant alleles of IL12RB2. RESULTS: The frequencies of variant alleles of IL12RB2 were significantly higher in aggressive periodontitis patients as compared with healthy controls or chronic periodontitis patients. Serum IgG titres against all periodontal bacteria examined in subjects carrying variant alleles were higher than those in subjects without variant alleles. CONCLUSION: IL-12Rbeta2 SNPs could be useful as genetic markers to access the susceptibility of the general population to periodontal disease. Low CMI responses or high humoral responses are associated with the pathogenesis of inflammatory periodontal diseases.

Epithelial-myoepithelial carcinoma arising in the nasal cavity.

This study documents a case of an epithelial-myoepithelial carcinoma (EMC) in the left nasal cavity. A 70-year-old woman who presented with recurrent epistaxis of the left nasal nostril of 3 months duration was found to have a polypoid tumor in the left nasal cavity. A computed tomography (CT) scan revealed a tumor to occupy the left inferior and middle nasal cavity which had destroyed the inferior nasal turbinate, and a horizontal scan showed the tumor to occupy the middle and posterior nasal cavity. Since the tumor was connected to the lateral wall of the left nasal cavity with a narrow stalk, the tumor was excised by peeling the mucosa from the wall of the left nasal cavity. Based on the histological and immunohistochemical findings, the tumor was diagnosed to be an EMC. The follow-up at 12 months after the operation showed no evidence of recurrence.

Iron-induced calcification in human aortic vascular smooth muscle cells through interleukin-24 (IL-24), with/without TNF-alpha.

In CKD patients, arteriosclerotic lesions, including calcification, can occur in vascular smooth muscle cells in a process called Moenckeberg's medial arteriosclerosis. Iron overload induces several complications, including the acceleration of arteriosclerosis. However, the relationship between Moenckeberg's arteriosclerosis in vascular smooth muscle cells and iron accumulation has remained unknown. We tested the accelerated effect of iron on calcification in cultured human aortic vascular smooth muscle cells (HASMCs). After establishment of this model, we performed a microarray analysis using mRNA from early stage culture HASMCs after iron stimulation with or without TNF-alpha stimulation. The role of interleukin-24 (IL-24) was confirmed from candidate genes that might contribute to calcification. HASMCs demonstrated calcification induced by iron and TNF-alpha. Calcification of HASMCs was synergistically enhanced by stimulation with both iron and TNF-alpha. In the early phase of calcification, microarray analysis revealed up-regulation of IL-24. Stimulation of HASMCs by IL-24 instead of iron induced calcification. The anti-IL-24 antibody reversed the effect of IL-24, supporting the important role of IL-24 in HASMCs calcification. In conclusion, iron-induced calcification in vascular smooth muscle cells occurred via IL-24, IL-24 was increased during the calcification process induced by iron, and IL-24 itself caused calcification in the absence of iron.

[A simple and accurate technique for cranioplasty in skull tumor surgery].

Cranioplasty using methylmethacrylate is a common method in patients with cranial defects. However, it is often difficult to precisely restore a removed cranium. The authors developed a new technique of cranioplasty. In the present study, we first made a cast composed of methylmethacrylate using a bone flap. We then covered the cast with a sheet of wet gauze. The implant was made by applying methylmethacrylate cement onto the gauze. The implant is firmly fixed to the cranium with titanium plates. Five cranioplasties were perfomed using this new technique. All patients achieved excellent cosmetic results with no complications. This technique enables low-cost, easy and cosmetically successful cranioplastic surgery.

Monocytes of distinct clinical types of leprosy are differentially activated by cross-linking class II HLA molecules to secrete IL-12.

Leprosy is characterized by a wide spectrum of clinical features depending on the individual differences in Th1-type immunity. The objective of this study was to evaluate whether monocyte activation by stimulus via class II HLA molecules would be correlated with the differences in cellular immune responses among diverse clinical forms of leprosy. IL-1beta and IL-12 productivity in monocyte preparations obtained from PBMCs was estimated in patients with lepromatous- and tuberculoid-type leprosy. We found that monocytes from lepromatous patients produced significantly higher (about 4-fold higher) amounts of IL-12 as compared to in patients with tuberculoid type of leprosy when class II HLA molecules were cross-linked with anti-HLA class II antibodies, whereas almost equal amounts of IL-1beta were produced from each monocyte preparation by stimulus via class II HLA molecules regardless of the clinical form of leprosy. These results suggest that monocyte activation differs between lepromatous and tuberculoid patients in terms of IL-12 secretion, which might be related to individual differences in the cellular immune responses according to the clinical type of leprosy.

Pulsed holmium:yttrium-aluminum-garnet laser-induced liquid jet as a novel dissection device in neuroendoscopic surgery.

OBJECT: A pressure-driven continuous jet of water has been reported to be a feasible tool for neuroendoscopic dissection owing to its superiority at selective tissue dissection in the absence of thermal effects. With respect to a safe, accurate dissection, however, continuous water flow may not be suitable for intraventricular use. The authors performed experiments aimed at solving problems associated with continuous flow by using a pulsed holmium:yttrium-aluminum-garnet (Ho:YAG) laser-induced liquid jet (LILJ). They present this candidate neuroendoscopic LILJ dissection system, having examined its mechanical characteristics and evaluated its controllability both in a tissue phantom and in a rabbit cadaveric ventricle wall. METHODS: The LILJ generator was incorporated into the tip of a No. 4 French catheter so that the LILJ could be delivered via a neuroendoscope. Briefly, the LILJ was generated by irradiating an internally supplied column of physiological saline with a pulsed Ho:YAG laser (pulse duration time 350 microsec; laser energy 250-700 mJ/pulse) within a No. 4 French catheter (internal diameter 1 mm) and ejecting it from a metal nozzle (internal diameter 100 microm). The Ho:YAG laser energy pulses were conveyed by an optical fiber (core diameter 400 microm) at 3 Hz, whereas physiological saline (4 degrees C) was supplied at a rate of 40 ml/hour. The mechanical characteristics of the pulsed LILJ were investigated using high-speed photography and pressure measurements; thermal effects and controllability were analyzed using an artificial tissue model (10% gelatin of 1 mm thickness). Finally, the ventricle wall of a rabbit cadaver was dissected using the LILJ. Jet pressure increased in accordance with laser energy from 0.1 to 2 bar; this translated into a penetration depth of 0.08 to 0.9 mm per shot in the ventricle wall of the rabbit cadaver. The gelatin phantom could be cut into the desired shape without significant thermal effects and in the intended manner, with a good surgical view. CONCLUSIONS: The present results show that the pulsed LILJ has the potential to become a safe and reliable dissecting method for endoscopic procedures.

Cell-adhesion molecule expression and the proliferation of malignant mesothelioma: a post-mortem examination.

AIM: In order to determine if metastatic malignant mesothelioma cells are more aggressive than primary malignant mesothelioma cells, an analysis of the expression of the adhesion molecules E-cadherin and ß-catenin, concomitant with an assessment of the proliferative activity at primary and metastatic sites, was conducted in post-mortem samples. MATERIALS AND METHODS: E-cadherin or ß-catenin expression was graded according to the percentage of positively-stained tumor cells. The proliferative activity was quantified by the Ki-67 labeling index. RESULTS: Histologically, the majority of metastatic tumors matched the primary tumor. In the epithelioid component of primary tumors, E-cadherin and ß-catenin expression ranged from 1+ to 4+. CONCLUSION: Malignant mesothelioma cells acquire a higher proliferative potential after metastasis, without any significant changes in their histology, although metastasis produces no definite trend on the expression of E-cadherin or ß-catenin.