Dendritic cells, T-cell infiltration, and Grp94 expression in cholangiocellular carcinoma

Although dendritic cells (DCs) play an important role in tumor immunity, there have been no reports on their role in cholangiocellular carcinoma (CCC). In 26 formalin-fixed, paraffin-embedded tissue sections from patients with CCC, cells positive for CD83 (a marker of mature DCs), CD1a (a marker of immature DCs), and CD8 and CD4 (T cell markers) were counted, and expression of glucose-regulated protein (grp) 94, which is considered to participate in the maturation of DCs, was evaluated by immunohistochemistry and Western blot analysis to study the relationship between their expression and patients' disease outcome. The number of CD83-positive DCs at the invasive margin of CCCs correlated significantly with the number of CD8-positive or CD4-positive T cells in the cancerous region and was significantly higher in grp94-positive cancer than in grp94-negative cancer (P = 0.0006). CD83-positive patients (positive cells in invasive margin > 12.4/field) had both a significantly lower incidence of lymph node metastasis (23.1% vs 69.2%; P = 0.0206) and a better outcome than CD83-negative patients (P <0.001). We conclude that mature DCs are distributed predominantly at the invasive margin of cancers, and a significantly higher number of mature DCs at the invasive margin are observed in patients with grp94-positive cancer cells. Mature DCs may enhance CD8- and CD4-positive cell infiltration into cancers and improve prognosis in patients with CCC, due in part to abatement of lymph node metastasis.     

A 3-year follow-up study of anti-Legionella antibodies in users of Japanese 24-hour hot water baths

Although it has been found that legionellae can exist in a 24-h hot water bath (24HHWB), which has been used recently in Japan, whether longer use of the 24HHWB causes legionellosis is unclear. The present longitudinal study was conducted in 2000 to investigate the 3-yr change in antibody titers in association with the continuous use, non-use, or canceling the use of the 24HHWB, and possible factors relating to the antibody changes. Ninety-two subjects (85 males and 7 females), who had had their anti-Legionella pneumophila (Lp) serum antibody titers measured in our initial study in 1997 and consented to blood sampling 3 yr later, were selected as subjects. There were no clinical cases who had experienced Legionnaires' disease or Pontiac fever during the 3 yr. The continuous users showed no significant changes in antibody titers within 3 yr, whereas the continuous non-users had a significant increase in antibody titers against the Lp serogroup (SG) 5 and 6. Eleven ex-users of the 24HHWB showed a significant decrease in antibody titers against Lp SG 6. The changes in the 24HHWB use, job sector, stress coping strategies, and alcohol-drinking habit were associated with the changes in antibody titers against Lp SG 1, 5 or 6. The anti-Lp antibodies were considered to be IgM dominant. In conclusion, this study indicates that 24HHWB use by healthy subjects does not tend to result in a higher onset risk of legionellosis, even if it is continuously used for 3 yr, although 24HHWB use is likely to induce production of antibodies against legionellae.     

Four new triterpenoids from Maytenus ilicifolia

Four new triterpenoids with various skeletons, maytefolins A-C (1-3) and uvaol-3-caffeate (4), were isolated from the leaves of a Brazilian medicinal plant, Maytenus ilicifolia, together with five known triterpenoids. Of these triterpenoids only erythrodiol exhibited significant cytotoxicity against KB/S, KB/VJ300, and KU 19-20 cells.     

Inhibition of metastasis of tumor cells overexpressing thymidine phosphorylase by 2-deoxy-L-ribose

Thymidine phosphorylase (TP) catalyzes the reversible conversion of thymidine to thymine, thereby generating 2-deoxy-D-ribose-1-phosphate, which upon dephosphorylation forms 2-deoxy-D-ribose (D-dRib), a degradation product of thymidine. We have previously shown that D-dRib promotes angiogenesis and chemotaxis of endothelial cells and also confers resistance to hypoxia-induced apoptosis in some cancer cell lines. 2-Deoxy-L-ribose (L-dRib), a stereoisomer of D-dRib, can inhibit D-dRib anti-apoptotic effects and suppressed the growth of KB cells overexpressing TP (KB/TP cells) transplanted into nude mice. In this study, we examined the ability of L-dRib to suppress metastasis of KB/TP cells using two different models of metastasis. The antimetastatic effect of L-dRib was first investigated in a liver-metastasis model in nude mice inoculated with KB/TP cells. Oral administration of L-dRib for 28 days at a dose of 20 mg/kg/day significantly reduced the number of metastatic nodules in the liver and suppressed angiogenesis and enhanced apoptosis in KB/TP metastatic nodules. Next, we compared the ability of L-dRib and tegafur alone or in combination to decrease the number of metastatic nodules in organs in the abdominal cavity in nude mice receiving s.c. of KB/TP cells into their backs. L-dRib (20 mg/kg/day) was significantly (P < 0.05) more efficient than tegafur (100 mg/kg/day) in decreasing the number of metastatic nodules in organs in the abdominal cavity. By in vitro invasion assay, L-dRib also reduced the number of invading KB/TP cells. L-dRib anti-invasive activity may be mediated by its ability to suppress the enhancing effect of TP and D-dRib on both mRNA and protein expression of vascular endothelial growth factor and interleukin-8 in cultured KB cells. These findings suggest that L-dRib may be useful in a clinical setting for the suppression of metastasis of tumor cells expressing TP.     

Distinct migratory behavior of early- and late-born neurons derived from the cortical ventricular zone

Time-lapse studies indicate that ventricular zone (VZ)-derived cells show two migratory modes in the cerebral cortex at different stages of mammalian embryogenesis: somal translocation and locomotion. We carried out a systematic analysis to examine whether the migratory behavior of cortical neurons derived from the cortical VZ is stage-dependent. We labeled VZ cells of mouse embryos with green fluorescent protein (gfp) -encoding plasmids by in utero electroporation and evaluated the labeled cells after appropriate survival periods. After electroporation at either embryonic day (E) 12.5 or E15.5, GFP+ VZ cells were initially spindle-shaped and radially oriented. After leaving the VZ, they transformed into round or horizontally oriented fusiform neurons with many short processes. They then seemed to gradually change into radially oriented bipolar cells as they moved upward. Whereas the earliest emigrants from the VZ labeled at E12.5 (early-born neurons) reached the top of the cortical plate (CP) after these changes, VZ cells labeled at E15.5 (late-born neurons) further migrated along the length of radial fibers to reach the top of the CP. A dominant negative form of the gene for cyclin-dependent kinase 5 (Cdk5DN) was then introduced into VZ cells. Transfection of E12.5 VZ with cdk5dn did not disrupt the migration of the early-born neurons. However, this caused a failure in migration of the late-born neurons, although they transformed into bipolar shapes in the intermediate zone. Thus, there appear to be at least two distinct migratory phases of cortical neurons: one common to the early- and late-born neurons, and the other specific to late-born neurons and Cdk5-dependent.     

Visualization of peptide presentation following oral application of antigen in normal and Peyer's patches-deficient mice

Orally applied antigens generate systemic unresponsiveness by induction of anergy and deletion of specific T cells at high antigen doses, and induction of regulatory T cells at low doses of antigen. These different immune reactions have been attributed to different types of antigen-presenting cells (APC) and/or different secondary lymphoid organs participating in the induction of the immune response. We used high-sensitivity immunofluorescence to directly identify for the first time the cells presenting orally applied antigen in vivo. At low peptide doses (<1 mg) peptide presentation was exclusively detected on dendritic cells (DC) of the Peyer's patches (PP) and mesenteric lymph nodes (mLN). At high doses (>1 mg) peptides were presented systemically and by all types of APC but presentation was still maximal on DC of the PP (up to 65%). Nevertheless, at limiting antigen doses T cell activation in the gut-associated lymphoid tissue occurs preferentially in the mLN but not in PP. PP-deficient mice have the same frequencies of peptide-presenting cells in mLN, peripheral lymph nodes and spleen and activation of naive T cells in vivo is not affected. Therefore, PP are not critical for antigen presentation as well as for T cell activation in response to orally applied soluble antigens.     

Disseminated infection due to Scedosporium apiospermum in a patient with acute myelogenous leukemia

A 62-year-old man diagnosed with acute myelogenous leukemia which had developed from myelodysplastic syndrome received cytarabine and idarubicine as an induction therapy. The patient developed pneumonia and bacterial sepsis during profound neutropenia. Fever and sepsis improved by using many anti-bacterials and anti-fungals but he became febrile again and complained of severe lumbar pain. 67Ga scintigram showed abnormal uptake in the lumbar vertebra and left sternoclavicular joint, suggesting a diagnosis of discitis and osteomyelitis in the lumbar vertebra and sternoclavicular arthritis. We biopsied the site several times but culture of the biopsy specimen could not isolate any pathogens, and high fever persisted for about 10 months despite administration of various anti-bacterials and anti-fungals. Finally we inserted a catheter into the abscess at the iliopsoas muscle and Scedosporium apiospermum was isolated in the bloody pus obtained from the catheter. Itraconazole and amphotericin B were restarted, and the high fever and lumbar pain improved rapidly. The findings of S. apiospermum infection in this patient emphasizes the importance of being aware of this pathogen in patients with hematologic malignancy during the neutropenic phase.     

Recurrent laryngeal nerve regeneration by tissue engineering

The recurrent laryngeal nerve (RLN) does not regenerate well after it has been cut, and no current surgical methods achieve functional regeneration. Here, we evaluate the functional regeneration of the RLN after reconstruction using a biodegradable nerve conduit or an autologous nerve graft. The nerve conduit was made of a polyglycolic acid (PGA) tube coated with collagen. A 10-mm gap in the resected nerve was bridged by a PGA tube in 6 adult beagle dogs (group 1) and by an autologous nerve graft in 3 dogs (group 2). Fiberscopic observation revealed functional regeneration of the RLN in 4 of the 6 dogs in group 1. No regeneration of the RLN was observed in any dog in group 2. We also tested for axonal transport, and measured the compound muscle action potential. The RLN can be functionally regenerated with a PGA tube, which may act as a scaffold for the growth of regenerating axons.     

MMPs initiate Schwann cell-mediated MBP degradation and mechanical nociception after nerve damage

Matrix metalloproteinases (MMPs) emerge as modulators of neuropathic pain. Because myelin protects Aβ afferents from ectopic hyperexcitability and nociception from innocuous mechanical stimuli (or mechanical allodynia), we analyzed the role of MMPs in the development of mechanical allodynia through myelin protein degradation after rat and MMP-9−/− mouse L5 spinal nerve crush (L5 SNC). MMPs were shown to promote selective degradation of myelin basic protein (MBP), with MMP-9 regulating initial Schwann cell-mediated MBP processing after L5 SNC. Acute and long-term therapy with GM6001 (broad-spectrum MMP inhibitor) protected from injury-induced MBP degradation, caspase-mediated apoptosis, macrophage infiltration in the spinal nerve and inhibited astrocyte activation in the spinal cord. The effect of GM6001 therapy on attenuation of mechanical allodynia was robust, immediate and sustained through the course of L5 SNC. In conclusion, MMPs mediate the initiation and maintenance of mechanical nociception through Schwann cell-mediated MBP processing and support of neuroinflammation.