Trypanocidal constituents in plants 2.xanthones from the stem bark of Garcinia subelliptica

The constituents of the stem bark of Garcinia subelliptica (Guttiferae) were investigated based on its trypanocidal activity against epimastigotes of Trypanosoma cruzi, the etiologic agent for Chagas' disease. As the active components, nine xanthones were isolated including two new ones, 4-hydroxybrasilixanthone B and 1,3,5,6-tetrahydroxy-4,7,8-tri(3-methyl-2-butenyl)xanthone. Their structures were determined by spectroscopic analysis. Trypanocidal activity against trypomastigotes, an infectious form of T. cruzi, was also estimated as well as cytotoxic activity. Fukugetin, the major component of the bark, showed no activity.     

Antiallodynic effect of etidronate, a bisphosphonate, in rats with adjuvant-induced arthritis: involvement of ATP-sensitive K+ channels

The role of inducible nitric oxide synthase (iNOS) in cerebral edema and neurological deficit following traumatic brain injury (TBI) is not yet clear-cut. Therefore, the aim of this study was to investigate the effect of three different iNOS inhibitors on cerebral edema and functional outcome after TBI. First, the time courses of blood--brain barrier (BBB) breakdown, cerebral edema, and neurological deficit were studied in a rat model of fluid percussion-induced TBI. The permeability of BBB to Evans blue was increased from 1 h to 24 h after TBI. Consistently, a significant increase in brain water content (BWC) was observed at 6 and 24 h post-TBI. A deficit in sensorimotor neurological functions was also observed from 6 h to 7 days with a maximum 24 h after TBI. Second, a single dose of aminoguanidine (AG; 100 mg/kg, i.p.), L-N-iminoethyl-lysine (L-NIL; 20 mg/kg, i.p.), or N-[3-(aminomethyl)benzyl]acetamide (1400W; 20 mg/kg, s.c.) was administered at 6 h post-TBI. Treatment with AG reduced by 71% the increase in BWC evaluated at 24 h, while L-NIL and 1400W had no effect. In contrast, the three iNOS inhibitors reduced the neurological deficit from 30% to 40%. Third, 1400W (20 mg/kg, s.c.) was administered at 5 min, 8 and 16 h post-TBI. Although this treatment paradigm had no effect on cerebral edema evaluated at 24 h, it significantly reduced the neurological deficit and iNOS activity. In conclusion, iNOS contributes to post-TBI neurological deficit but not to cerebral edema. The beneficial effect of iNOS inhibitors is not due to their anti-edematous effect, and the reduction of cerebral edema by AG is unlikely related to iNOS inhibition. The 6 h therapeutic window of iNOS inhibitors could allow their use in the treatment of functional deficit at the acute phase of TBI.     

Role of mitochondrial membrane permeability transition in N-nitrosofenfluramine-induced cell injury in rat hepatocytes

The role of mitochondrial membrane permeability transition in N-nitrosofenfluramine-induced cell injury was studied in mitochondria and hepatocytes isolated from rat liver. Mitochondrial permeability transition has been proposed as a common final pathway in acute cell death through mitochondrial dysfunction. In isolated mitochondria, N-nitrosofenfluramine (0.25 to 1.0 mM) in the presence of Ca(2+) (50 microM) elicited a concentration-dependent induction of mitochondrial swelling dependent on mitochondrial permeability transition and the release of cytochrome c, both of which were prevented by pretreatment with a specific inhibitor of mitochondrial permeability transition, cyclosporin A (0.2 microM). The effects of N-nitrosofenfluramine on mitochondria were more potent than those of fenfluramine, which is a sympathomimetic amine with anorectic action. The pretreatment of isolated hepatocytes with cyclosporin A (2 microM) partially but not completely prevented N-nitrosofenfluramine (0.6 mM; a low toxic dose)-induced cell death, loss of cellular ATP, formation of cell blebs and decrease in mitochondrial membrane potential. These results suggest that the onset of N-nitrosofenfluramine-induced cytotoxicity is linked to mitochondrial failure dependent upon induction of mitochondrial permeability transition accompanied by mitochondrial depolarization, the release of cytochrome c and depletion of intracellular ATP through uncoupling of oxidative phosphorylation.     

Phase II study of combination chemotherapy with gemcitabine and irinotecan in patients with advanced non-small-cell lung cancer previously treated with platinum-containing chemotherapy regimens

OBJECTIVE: The aim of this study was to evaluate the efficacy and toxicity of gemcitabine combined with irinotecan in patients with previously treated non-small-cell lung cancer (NSCLC). METHODS: Patients who failed to respond to platinum-containing first-line chemotherapy were enrolled and treated with gemcitabine 1000 mg/m(2) and irinotecan 150 mg/m(2) on days 1 and 15. Cycles were repeated every 4 weeks. RESULTS: Twenty-seven of 30 registered patients were evaluated. There were previous combination treatments of platinum and taxane regimens in 21 out of 27 patients, with 17 patients treated with carboplatin and paclitaxel and 4 patients treated with cisplatin or carboplatin and docetaxel. A total of 87 cycles was administered and the median number of cycles administered per patient was 3.5 cycles. Objective responses were observed in 5 out of 27 patients (18.5%). No severe hematologic and non-hematologic toxicities were observed (grade 3 leukopenia in 3 patients; grade 3 anemia in 3 patients; grade 3 thrombocytopenia in 2 patients; grade 3 diarrhea in 1 patient). The median survival time was 7.7 months and 1-year survival rate was 34.8%. CONCLUSION: Bi-weekly gemcitabine and irinotecan was well tolerated and had an acceptable response rate and a reasonable median survival time for patients with NSCLC who had previously been treated with platinum-based chemotherapy.     

Biochemical and genetic analysis of toxic effect of HOE 15030 in mammalian cells

HOE 15030 inhibited the growth of BHK cells at concentrations that did not inhibit their nuclear DNA and RNA syntheses. When BHK cells were cultured in the presence of 30 g/ml of HOE 15030, cells were arrested in the G₁ phase after one or two cell divisions. After removal of the drug, cells progressed through the G₁ to the S phase. HOE 15030 inhibited the activities of both topoisomerases I and II in vitro. To determine the target molecule of HOE 15030 in cells, we isolated a HOE 15030-resistant (HOE^r) mutant of BHK cells. The HOE^r cells exhibited cross-resistance to ethidium bromide, acriflavine, and rhodamine 123, and slight cross-resistance to 4-dimethylepipodophyllotoxin-4-(4,6-O -ethylidine--d-glucopyranoside) (VP-16) and adriamycin, but not to chloramphenicol, oligomycin, novobiocin, colchicine, or vinblastine. The uptake and retention of rhodamine 123 by HOE^r cells were lower than those by BHK cells. Mitochondrial DNA synthesis of HOE^r cells was more resistant to HOE 15030 and ethidium bromide than that of wild-type cells. These results indicate that the resistance of HOE^r cells to drugs is due to reduced uptake or accumulation of the drugs by mitochondria and suggest that the mitochondria are the main target of HOE 15030 in cells.     

Role of the complement-lectin pathway in anaphylactoid reaction induced with lipopolysaccharide in mice

We show that Proteus vulgaris O25 (PO25) lipopolysaccharide (LPS) induced an anaphylactoid reaction not only in wild-type and in lipid A non-responding mice but also in recombinase-activating gene-2-deficient (RAG-2(-/-)) and in mast cell-deficient (W/Wv) animals. Western blot analysis indicated that PO25 LPS bound to Ra-reactive factor (RaRF), the complex of mannan-binding lectins (MBL) and MBL-associated serine proteases. Binding of RaRF to PO25 LPS led to the activation of C4 component without participation of either C1 or Ig, via the lectin pathway. Relative concentration of RaRF and hemolytic activity in mouse serum decreased rapidly during the process of anaphylactoid reaction. A significant drop of MBL-A, but not MBL-C level was observed. Administrationwith antiserum to RaRF prevented animals from death as a consequence of the inhibition of interaction of RaRF with the carbohydrate target and complement activation. These results indicate that complement-lectin pathway activation is responsible for the anaphylactoid reaction induced with LPS in muramyldipeptide-primed mice. RaRF also activated fibrinogen in vitro suggesting the involvement of the coagulation system in the process investigated.     

Macrophages in tumor-draining lymph node with different characteristics induce T-cell apoptosis in patients with advanced stage-gastric cancer

A host's immune-defense system is suppressive by many factors in patients with cancer. We have previously shown one possible mechanism behind the T-cell dysfunction, whereby H(2)O(2) secreted from macrophages in tumor-draining lymph node (MTDL) induced T-cell dysfunction with down-regulation of TCR zeta molecules. In the present study, we analyzed how MTDL affect T cells, with a particular focus on T-cell apoptosis, by co-culturing MTDL with autologous peripheral blood T cells in gastric cancer. Moreover, we characterized the MTDL according to surface marker, oxygen-burst capacity and intracellular cytokine status. T-cell apoptosis was significantly induced in comparison to T-cell alone control in patients with advanced disease, concomitant to the elevated caspase activity and following impaired T-cell function. In patients with early disease, no significant difference was seen in the proportions of T cells that underwent apoptosis between T cells plus MTDL and T cells alone. Moreover, the addition of a selective scavenger of H(2)O(2), catalase inhibited the apoptosis of T cells co-cultured with MTDL in patients with advanced disease. In the characterization of MTDL, the production of H(2)O(2) in MTDL from advanced disease was significantly higher than that in early disease. The amounts of intracellular IL-10 and IL-12 in MTDL in advanced disease were significantly higher than those in early disease. These results indicated that MTDL induced apoptosis of autologous T cells and this T-cell dysfunction was mediated by H(2)O(2) derived from MTDL. Furthermore, the characteristics of MTDL including the capacity of oxygen-burst and intracellular cytokine production were different depending on the disease progression.     

Bronchial artery embolization for hemoptysis: Immediate and long-term results

The purpose of this study was to evaluate the immediate and long-term results in 63 patients who underwent transarterial embolization for control of hemoptysis. Overall immediate success rate was 86.1%. At long-term follow-up 50% of patients showed complete remission, 22% partial remission, and 28% recurrent hemoptysis. Hemoptysis remained controlled for a mean of 22 months and a median of 14 months. The long-term results among four disease groups differed substantially. Patients with bronchiectasis showed the best results, followed by those with idiopathic disease and with inflammation; patients with neoplasm showed the worst results.     

Cell-surface changes accompanying aging in human diploid fibroblasts: Effects of tissue,donor age and genotype

The generality of age-related changes in concanavalin A (Con A)-mediated red blood cell (RBC) adsorption to human diploid fibroblasts was investigated on fibroblast-like cells from fetal lung, heart, liver, skin and muscle tissues. All the cells examined showed the continuous increase from early passages in RBC adsorption with the RBC coating method (in which Con A-coated RBCs are adsorbed to fibroblasts) and the increase only at phase III with the fibroblast coating method (in which RBCs are adsorbed to Con A-coated fibroblasts). All of the four strains of lung fibroblasts gave nearly the same extent of the age-related change in RBC adsorption, when expressed as a function of percentage life span consumed, indicating that the change in RBC adsorption is independent of genetic heterogeneity and the conditions of primary culture. Liver and heart fibroblasts also gave results similar to those of lung fibroblasts. However, skin and muscle fibroblasts were lower in their RBC adsorption capacity throughout the life span. The continuous age-related increase in RBC adsorption to these cells could be sensitized by using glutaraldehyde-prefixed RBCs, trypsinized RBCs or phytohemagglutinin P in place of Con A. The relevance of the phenotype of in vitro aging revealed by RBC adsorption to in vivo aging was also demonstrated on skin fibroblasts from different ages of donors using glutaraldehyde-prefixed RBCs. In addition, fibroblasts from patients with Werner's syndrome, an hereditary disease manifested by early and widespread degenerative changes, showed senescent phenotype in RBC adsorption even at early passages.