Terreic acid, a quinone epoxide inhibitor of Bruton's tyrosine kinase

Bruton's tyrosine kinase (Btk) plays pivotal roles in mast cell activation as well as in B cell development. Btk mutations lead to severe impairments in proinflammatory cytokine production induced by cross-linking of high-affinity IgE receptor on mast cells. By using an in vitro assay to measure the activity that blocks the interaction between protein kinase C and the pleckstrin homology domain of Btk, terreic acid (TA) was identified and characterized in this study. This quinone epoxide specifically inhibited the enzymatic activity of Btk in mast cells and cell-free assays. TA faithfully recapitulated the phenotypic defects of btk mutant mast cells in high-affinity IgE receptor-stimulated wild-type mast cells without affecting the enzymatic activities and expressions of many other signaling molecules, including those of protein kinase C. Therefore, this study confirmed the important roles of Btk in mast cell functions and showed the usefulness of TA in probing into the functions of Btk in mast cells and other immune cell systems. Another insight obtained from this study is that the screening method used to identify TA is a useful approach to finding more efficacious Btk inhibitors.     

Tumor necrosis factor-related apoptosis-inducing ligand induces neuronal death in a murine model of HIV central nervous system infection

HIV-1 infection in the brain induces neuronal apoptosis leading to HIV-associated dementia. To explore the underlying mechanism, we developed a murine model by using human peripheral blood mononuclear cell (PBMC)-transplanted nonobese diabetic (NOD)-severe combined immunodeficiency (SCID) (hu-PBMC-NOD-SCID) mice. Administration of lipopolysaccharide (LPS) to HIV-1-infected hu-PBMC-NOD-SCID mice induced infiltration of HIV-1-infected human cells into the perivascular region of the brain and neuronal apoptosis was found in macrophage (M)-tropic but not T cell (T)-tropic HIV-1-infected brains. The apoptotic neurons were frequently colocalized with the HIV-1-infected macrophages that expressed tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). Administration of a neutralizing antibody against human TRAIL but not human TNF-alpha or Fas ligand (FasL) blocked the neuronal apoptosis in the HIV-1-infected brain. These results strongly suggest a critical contribution of TRAIL expressed on HIV-1-infected macrophages to neuronal apoptosis.     

Suppressing effects of daily oral supplementation of beta-glucan extracted from Agaricus blazei Murill on spontaneous and peritoneal disseminated metastasis in mouse model

Purpose: The Basidiomycete fungus Agaricus blazei Murill has traditionally been used as a health food for the prevention of cancer. Methods: We examined whether beta-(1–6)-D-glucan extracted from A. blazei is a potential anticancer agent in an in vitro and in vivo animal model. Results: Here we show that (1) beta-glucan had cytotoxic effect against human ovarian cancer HRA cells, but not against murine Lewis lung cancer 3LL cells, in vitro; (2) beta-glucan promotes p38 MAPK activity for suppressing HRA cell proliferation and amplifying the apoptosis cascade; (3) beta-glucan stimulates translocation of the proapoptotic protein, Bax, from the cytosol to mitochondria, cytochrome c release, and subsequent caspase-9 activation; (4) treatment with SB203580, a p38 MAPK-specific inhibitor, suppresses beta-glucan-induced effects, indicating that activation of p38 MAPK is involved in the suppression of cell proliferation and mitochondrial activation-mediated cell death pathway; (5) in mice, oral supplementation with beta-glucan reduces pulmonary metastasis of 3LL cells and peritoneal disseminated metastasis of HRA cells and inhibits the growth of these metastatic tumors in lung or peritoneal cavity, in part, by suppressing uPA expression; and (6) in an in vivo experimental metastasis assay, however, the oral supplementation with beta-glucan after i.v. tumor cell inoculation did not reduce the number of lung tumor colonies. Conclusion: Treatment with beta-glucan may be beneficial for cancer patients with or at risk for metastasis. The beta-glucan-dependent signaling pathways are critical for our understanding of anticancer events and development of cancer therapeutic agents.     

Defucosylated anti CC chemokine receptor 4 monoclonal antibody combined with immunomodulatory cytokines: a novel immunotherapy for aggressive/refractory Mycosis fungoides and Sezary syndrome.

PURPOSE: Sézary syndrome (SS) and Mycosis fungoides (MF) in the advanced stage have dismal prognoses. Because CC chemokine receptor 4 (CCR4) has an important role in the skin-homing capacity of MF/SS cells, we postulated that anti-CCR4 monoclonal antibody (mAb) could represent a novel therapeutic agent against aggressive/refractory MF/SS. EXPERIMENTAL DESIGN: The defucosylated next-generation therapeutic mAb KM2760 induces enhanced antibody-dependent cellular cytotoxicity (ADCC). Here, we assessed the therapeutic potential of this antibody against aggressive MF/SS tumor cells in vitro and in animal models in vivo. RESULTS: KM2760 induced robust ADCC by peripheral blood mononuclear cell (PBMC) from healthy controls against a MF/SS cell line as well as against primary tumor cells from patients with aggressive MF/SS. KM2760 also showed significant antitumor activity in disseminated and nondisseminated MF/SS mouse models. In addition, approximately 30% of autologous MF/SS tumor cells were killed in in vitro assays of KM2760-induced ADCC mediated by patients' PBMC after only 4 h, despite the low numbers of natural killer cells present in these PBMCs. It is also shown that ADCC induced by defucosylated therapeutic mAb can be greatly augmented by the immunomodulatory cytokines interleukin-12, IFN-alpha-2b, and IFN-gamma. CONCLUSIONS: The present study has encouraged us in the conducting of a phase I clinical trial of a completely defucosylated anti-CCR4 mAb in patients with CCR4-positive T-cell lymphomas, including aggressive MF/SS (ClinicalTrials.gov identifier: NCT00355472). In the near future, the efficacy not only of defucosylated anti-CCR4 mAb single-agent treatment but also of combination therapy with immunomodulatory cytokines will be clinically established to target aggressive/refractory MF/SS.     

Conventional X-ray versus CT in diagnosis of chronic sinusitis in children]

The interpretation of conventional radiographic views for sinusitis in children has given rise to considerable controversy. Thirty-three children (66 sides of sinuses) aged from 4 to 15 years who were suspected of having chronic sinusitis were studied to determine the accuracy of conventional X-ray examination, comparing the results with those of CT. Coronal CT was taken after conventional X-ray examination (Waters and occipito-frontal views), and the time interval between these two examinations was 0 to 14 days (average 5.1 days). The rate of correspondence in diagnosis of sinus pathology between conventional X-ray views and CT was 74.3% in the maxillary sinus and 40.9% in the ethmoid. The rate of overestimation with conventional X-ray views was 24.2% in the maxillary sinus and 56.1% in the ethmoid, while that of underestimation was 1.5% and 3.0% in the maxillary and the ethmoid sinus respectively. The incidence of false positives according to conventional X-ray views was 8.0% in the maxillary sinus and 33.3% in the ethmoid. Our results indicate that Waters view is sufficient to diagnose maxillary sinus pathology in children. However, additional radiologic examinations, such as CT, are necessary in investigating the pathologic conditions of the ethmoid sinus, since diagnostic significance of occipito-frontal view for ethmoid pathology is doubtful in children. A routine preoperative CT is recommended, which allows a detailed evaluation of pathologic changes and anatomical relations of the ethmoid before embarking a surgical intervention for the ethmoid sinus in children.     

A wide interindividual variability of urinary 6beta-hydroxycortisol to free cortisol in 487 healthy Japanese subjects in near basal condition

The frequency distribution of CYP3A activity was investigated by measuring ratios of urinary 6beta-hydroxycortisol to free cortisol in 487 healthy subjects to determine whether a genetic polymorphism for this cytochrome enzyme exists in "native-born" Japanese persons. Spot urine samples (from 9:00 am to 12:00 pm) were collected for measurement of 6beta-hydroxycortisol and free cortisol by high-performance liquid chromatography with a CN column after extracting with a solid-phase column (Bond-Elut C18). The frequency distribution of the urinary 6beta-hydroxycortisol to free cortisol was widely distributed among subjects but with no clear bimodality by a probit plot. Furthermore, the frequency distribution assessed on a new normal test variable plot indicated the possible existence of a CYP3A sexual dimorphism. Mean 6beta-hydroxycortisol levels were higher in women (n = 249) than in men (n = 238) by 1.7-fold, and this difference was statistically significant (P < 0.01). These results show that a CYP3A genetic polymorphism in Japanese persons, based on 6beta-hydroxycortisol excretions, likely does not exist, but there appears to be a broad unimodal distribution of enzyme activity in the population.     

Perturbation of secretory Ig A in saliva and its daily variation by academic stress

Objectives Several studies have reported that the secretory immunoglobulin A (S-IgA) concentration in saliva is an indicator of psychological stress. The aim of this study was to clarify the relationship between S-IgA and the stress from academic examinations. Methods S-IgA levels in 10 medical student volunteers from the second year course between May 4 and July 13, 2000 were examined using the ELISA method. Results There was a tendency for S-IgA in saliva to be higher on the day before academic examinations and during them, and lower on the days between these examinations. Conclusions It may be possible to use this measurement to monitor psychological stress in students and workers. Second year medical student in the year 2000.     

A novel antibiotic CJ-17,572 from a fungus, Pezicula sp

A new antibiotic, CJ-17,572 (I) was isolated from the fermentation broth of a fungus Pezicula sp. CL11877. The structure of I was determined to be a new equisetin derivative by spectroscopic analyses. The compound inhibits the growth of multi-drug resistant Staphylococcus aureus and Enterococcusfaecalis with IC50s of 10 and 20 microg/ml, respectively.