Colchicine-induced apoptosis and anti-Fas localization in rat-incisor ameloblasts

Apoptosis of ameloblasts were examined by the TdT-mediated dUTP-biotin nick end-labelling method and electron microscopy 8 h after injection of colchicine. The results showed that extensive apoptosis occurred in ameloblasts of secretion to maturation zones. To determine the possible involvement of stimulators in ameloblast apoptosis, Fas, Fas ligand, tumor-necrosis-factor α, and tumor-necrosis-factor receptor 1 were examined utilizing immunohistochemistry and Western blotting analysis. Only Fas was consistently detected in the secretion, transition and maturation ameloblasts and overlying enamel organ epithelia. These results suggest that ameloblasts could undergo apoptosis by colchicine and that one of the ameloblast apoptosis mediators would be the Fas receptor.     

High growing ability of Vibrio vulnificus biotype 1 is essential for production of a toxic metalloprotease causing systemic diseases in humans

Vibrio vulnificus biotype 1, a causative agent of fatal septicemia or wound infection in humans, is known to produce a toxic metalloprotease as an important virulence determinant. V. vulnificus biotype 2 (serovar E), a primary eel pathogen, was found to elaborate an extracellular metalloprotease that was indistinguishable from that of biotype 1. The potential of V. vulnificus biotype 1 for production of the metalloprotease was compared with biotype 2 and other human non-pathogenic Vibrio species (Vibrio anguillarum and Vibrio proteolyticus). When cultivated at 25 degrees C in tryptone-yeast extract broth supplemented with 0.9% NaCl, all bacteria multiplied sufficiently and secreted significant amounts of the metalloprotease. However, at 37 degrees C with 0.9% NaCl, V. anguillarum neither grew nor produced the metalloprotease. In human serum, only V. vulnificus biotype 1 revealed a steady multiplication accompanied with production of the extracellular metalloprotease. This prominent ability of biotype 1 in growth and protease production may contribute to cause serious systemic diseases in humans.     

Correlation of dendritic cell infiltration with active crypt inflammation in ulcerative colitis

The aim of this study was to evaluate the histological localization and phenotypic characteristics of infiltrating dendritic cells (DCs) and to examine the relationship between the degree of DC infiltration and the severity of inflammation in the colonic mucosa in ulcerative colitis (UC). Also explored was the expression of macrophage inflammatory protein-3alpha (MIP-3alpha), and its receptor CC-chemokine receptor 6 (CCR6), to evaluate the significance of immature DCs in the crypt inflammation evident in UC. There was a significant positive correlation between the number of infiltrating DCs and the degree of crypt inflammation, mononuclear cell infiltration, crypt atrophy, and comprehensive active inflammation. No significant correlation between the number of S-100 protein(+) cells and the severity of crypt atrophy was found. S-100 protein(+), MIP-3alpha(+), and CCR6(+) cells were frequently localized in or around the crypt with inflammation. MIP-3alpha(+) neutrophils and S-100 protein(+) CCR6(+) cells with dendritic morphology were detected in or around the crypt inflammation. Both S-100 protein(+) DCs and CCR6(+) cells were frequently clustered in the surface mucosa beneath the surface epithelium when the crypt was not inflamed. CD1a(+) Langerhans-cell-type DCs were not found in any of the tissues examined. These data indicate that DCs participate not only in chronic inflammation but also in active crypt inflammation.     

Prostaglandin E(2) enhances axonal transport and neuritogenesis in cultured mouse dorsal root ganglion neurons

The effects of prostaglandin E₂ on axonal transport in cultured mouse dorsal root ganglion neurons were investigated by analysing the number of axonally transported particles under video-enhanced microscopy. Application of prostaglandin E₂ increased the number of particles transported in anterograde and retrograde directions. The EP₂ prostaglandin receptor agonist butaprost mimicked the effect of prostaglandin E₂, but the EP₁/EP₃ prostaglandin receptor agonist 17-phenyl trinor prostaglandin E₂ and the EP₃ prostaglandin receptor agonist M&B 28767 had no effect. The membrane-permeable cyclic AMP analogue dibutyryl cyclic AMP and the adenylate cyclase activator forskolin mimicked the effect of prostaglandin E₂. The protein kinase A inhibitor H-89 reversibly reduced the number of particles in both anterograde and retrograde directions. The effects of prostaglandin E₂ and dibutyryl cyclic AMP were blocked by H-89. Taken together with previous biochemical studies showing that prostaglandin E₂ increases cyclic AMP levels, the present results suggest that prostaglandin E₂ enhances axonal transport via the EP₂ receptor and cyclic AMP-dependent protein kinase A pathway. We further investigated the role of prostaglandin E₂ in neurite growth. Prostaglandin E₂ increased both the number of cells exhibiting neurites and the neurite growth rate, operating by a similar mechanism to stimulation of axonal transport.

Prostaglandin E₂ may modulate axonal transport to supply materials for morphogenesis as well as other functions in sensory neurons.     

Aberrant crypt foci as precursors of the dysplasia-carcinoma sequence in patients with ulcerative colitis

PURPOSE: Long-standing ulcerative colitis (UC) predisposes patients to the development of colorectal cancer, but surveillance of colitis-associated cancer by detecting the precancerous lesion dysplasia is often difficult because of its rare occurrence and normal-looking appearance. In sporadic colorectal cancer, aberrant crypt foci (ACF) have been reported by many investigators to be precursor lesions of the adenoma-carcinoma sequence. In the present study, we analyzed the genetic background of ACF to determine whether they could be precursors for dysplasia, and we examined the usefulness of endoscopic examination of ACF as a surrogate marker for surveillance of colitis-associated cancer. EXPERIMENTAL DESIGN: ACF were examined in 28 UC patients (19 patients with UC alone and 9 patients with UC and dysplasia; 2 of those patients with dysplasia also had cancer) using magnifying endoscopy. K-ras, APC, and p53 mutations were analyzed by two-step PCR RFLP, in vitro--synthesized protein assay, and single-strand conformation polymorphism, respectively. Methylation of p16 was analyzed by methylation-specific PCR. RESULTS: ACF that appeared distinct endoscopically and histologically were identified in 27 out of 28 UC patients. They were negative for K-ras, APC, and p53 mutations but were frequently positive for p16 methylation (8 of 11; 73%). In dysplasia, K-ras and APC mutations were negative but p53 mutation (3 of 5; 60%) and p16 methylation (3 of 5; 60%) were positive. There was a significant stepwise increase in the number of ACF from patients with UC alone to patients with dysplasia and to patients with cancer. Univariate and multivariate analyses showed significant correlations between ACF and dysplasia. CONCLUSIONS: We have disclosed an ACF-dysplasia-cancer sequence in colitis-associated carcinogenesis similar to the ACF-adenoma-carcinoma sequence in sporadic colon carcinogenesis. This study suggests the use of ACF instead of dysplasia for the surveillance of colitis cancer and warrants further evaluation of ACF as a surveillance marker in large-scale studies.     

Avascular necrosis of bone in neuroblastoma treated with combination chemotherapy

We treated two children with neuroblastoma and during the course of chemotherapy, avascular necrosis of the femoral head occurred. The main pathogenetic factor of this necrosis may be the toxic effect of cyclophosphamide.Abbreviations VMA vanillylmandelic acid - HVA homovanillic acid     

Neuritogenesis of herbal (+)- and (-)-syringaresinols separated by chiral HPLC in PC12h and Neuro2a cells

Syringaresinol isolated from Epimedium koreanum NAKA1 and Magnolia officinalis REHD. et WILS. was subjected to optical resolution by chiral HPLC to give (+)- and (-)-enantiomers. The two syringaresinol enantiomers, as well as a mixture of their glucosides, showed dose-dependent neuritogenesis in a concentration range from 0.24 to 24 microM in PC12h cells.     

Role of kinin and prostaglandin in cutaneous thermal nociception

Involvements of kinin and prostaglandin and their interaction in noxious thermal stimuli were investigated in noninflamed and inflamed rats. The nociceptive response was evaluated from the escape latency of foot withdrawal to the thermal stimuli with a beam of light. The escape latency in kininogens-deficient Brown Norway (B/N-) Katholiek rats was significantly longer than that in the normal strain, B/N-Kitasato rats. The latency in B/N-Kitasato rat was prolonged by administration of a bradykinin (BK) B2 receptor antagonist, FR173657 (30 mg/kg, p.o.), whereas it was shortened by pretreatment with a kininase II inhibitor, captopril (10 mg/kg, i.p.). Both agents did not affect the latency in B/N-Katholiek rats. In normal Sprague-Dawley (SD) rat, administration of indomethacin did not change the escape latency against the thermal stimuli. In contrast, administration of indomethacin or a relatively cyclooxygenase-1-selective inhibitor, mofezolac (10 mg/kg, p.o.) significantly reduced numbers of writhing reaction in mice induced by acetic acid solution. Injection of lipopolysaccharide (1 mg/kg, i.v.) resulted in shortening escape latency at 8 h after the injection in B/N-Kitasato rats. This hyperalgesia could be reversed by pretreatment of the rats with indomethacin, a cyclooxygenase-2-selective inhibitor JTE-522 (10 mg/kg, p.o.), or FR173657, but not with mofezolac. The hyperalgesia was not seen in B/N-Katholiek rats. These results indicate that kinin has major participation in peripheral skin thermal nociception under noninflamed condition, although cyclooxygenases may have little participation. Prostaglandins produced by cyclooxygenase-2 could coordinate with BK to elicit hyperalgesia during inflammation induced by lipopolysaccharide.