Ordered mesoporous carbon-carbon nanotube nanocomposites as highly conductive and durable cathode catalyst supports for polymer electrolyte fuel cells

Ordered mesoporous carbon-carbon nanotube (OMC-CNT) nanocomposites were prepared and used as catalyst supports for polymer electrolyte fuel cells. The OMC-CNT composites were synthesized via a nanocasting method that used ordered mesoporous silica as a template and Ni-phthalocyanine as a carbon source. For comparison, sucrose and phthalocyanine were used to generate two other OMCs, OMC(Suc) and OMC(Pc), respectively. All three carbons exhibited hexagonally ordered mesostructures and uniform mesopores. Among the three carbons the OMC-CNT nanocomposites showed the highest electrical conductivity, which was due to the nature of their graphitic framework as well as their lower interfacial resistance. The three carbons were then used as fuel cell catalyst supports. It was found that highly dispersed Pt nanoparticles (ca. similar to 1.5 nm in size) could be dispersed on the OMCs via a simple impregnation-reduction method. The activity and kinetics of the oxygen reduction reaction (ORR), measured by the rotating ring-disk electrode technique revealed that the ORR over the Pt/OMC catalysts followed a four-electron pathway. Among the three Pt/OMC catalysts, the Pt/OMC-CNT catalyst resulted in the highest ORR activity, and after an accelerated durability test the differences in the ORR activities of the three catalysts became more pronounced. In single cell tests, the Pt/OMC-CNTbased cathode showed a current density markedly greater than those of the other two cathodes after a high-voltage degradation test. These results were supported by the fact that the Pt/OMC-CNT-based cathode had the lowest resistance, which was probed by electrochemical impedance spectroscopy (EIS). The results of the single cell tests as well as those of the EIS-based measurements indicate that the rigidly interconnected structure of the OMC-CNT as well as their highly conductive frameworks are concomitantly responsible for the OMC-CNT nanocomposites exhibiting higher current density and durability than the other two carbons.close17

Reduced Dose Intensity FOLFOX-4 as First Line Palliative Chemotherapy in Elderly Patients with Advanced Colorectal Cancer

To evaluate the toxicity and efficacy of a reduced dose intensity (mini-) FOLFOX-4 regimen as a first-line palliative chemotherapy in elderly patients (≥70 yr of age) with advanced colorectal cancer, data from prospective databases at Seoul National University Bundang Hospital and Seoul Municipal Boramae Hospital were analyzed. A total of 20 patients were enrolled between January 2001 and August 2004, and were treated with oxaliplatin 65 mg/m2 on day 1, and with 2-hr infusions of leucovorin 150 mg/m2 followed by a 5-FU bolus (300 mg/m2) and 22-hr continuous infusions (450 mg/m2) for 2 consecutive days every 2 weeks until progression, unacceptable toxicity or patient refusal. Sixteen patients were evaluable for response with an overall response rate of 43.8%. Median progression-free survival was 4.8 months (95% CI: 3.0-6.7) and overall survival was 13.5 months (95% CI: 11.1-16.0). The main side effects were anemia and neutropenia, which were observed in 20.8% and 17.7%, respectively, of the total cycles administered. There were no grade 4 toxicities and only one patient suffered from febrile neutropenia. No grade 3 toxicities occurred except for anemia (5.2%) and vomiting (1.0%). In conclusion, the mini-FOLFOX-4 regimen was found to be well tolerated with acceptable toxicity, and to provide a benefit for elderly patients with colorectal cancer

Co-transplantation of Human Mesenchymal Stem Cells Promotes Human CD34+ Cells Engraftment in a Dose-dependent Fashion in NOD/SCID Mice

Mesenchymal stem cells (MSCs) have recently been identified and characterized in humans. Moreover, MSC secrete cytokines that can support hematopoietic progenitor growth. In the present study, we evaluated whether the efficacy of hematopoietic stem cell transplantation is improved by their co-transplantation with MSC, and whether this is positively correlated with the dose of infused MSCs. Accordingly, irradiated NOD/SCID mice were transplanted with 1×105 human CD34+ cells in the presence or absence of culture expanded MSCs (1×106 or 5×106). We evaluated human hematopoietic cell engraftment by flow cytometry and assessed MSC tissue distributions by fluorescence in situ hybridization. We found that CD45+ and CD34+ cell levels were significantly elevated in a dose-dependent manner in cotransplanted mice 4 weeks after transplantation. The engraftments of CD33+ and CD19+ cells also increased dose-dependently. However, the engraftment of CD3+ cells did not increase after co-transplantation with MSCs. Human Y chromosome+ cells were observed in multiple tissues and were more frequently observed in mice co-transplanted with 5×106 rather than 1×106 MSCs. These results suggest that MSCs are capable of enhancing hematopoietic cell engraftment and distribution in multiple organs in a dose-dependent fashion

Ginkgo biloba extract (GbE) enhances the anti-atherogenic effect of cilostazol by inhibiting ROS generation

In this study, the synergistic effect of 6-[4-(1-cyclohexyl-1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2(1H)-quinolinone (cilostazol) and Ginkgo biloba extract (GbE) was examined in apolipoprotein E (ApoE) null mice. Co-treatment with GbE and cilostazol synergistically decreased reactive oxygen species (ROS) production in ApoE null mice fed a high-fat diet. Co-treatment resulted in a significantly decreased atherosclerotic lesion area compared to untreated ApoE mice. The inflammatory cytokines and adhesion molecules such as monocyte chemoattractant-1 (MCP-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and VCAM-1 which can initiate atherosclerosis were significantly reduced by the co-treatment of cilostazol with GbE. Further, the infiltration of macrophages into the intima was decreased by co-treatment. These results suggest that co-treatment of GbE with cilostazol has a more potent anti-atherosclerotic effect than treatment with cilostazol alone in hyperlipidemic ApoE null mice and could be a valuable therapeutic strategy for the treatment of atherosclerosis

Phase II Study of Low-dose Paclitaxel and Cisplatin as a Second-line Therapy after 5-Fluorouracil/Platinum Chemotherapy in Gastric Cancer

This study was performed to evaluate the efficacy and toxicity of low-dose paclitaxel/cisplatin chemotherapy in patients with metastatic or recurrent gastric cancer that had failed 5-fluorouracil/platinum-based chemotherapy. Thirty-two patients with documented progression on or within 6 months after discontinuing 5-fluorouracil/platinum-based chemotherapy were enrolled. As a second-line treatment, paclitaxel (145 mg/m2) and cisplatin (60 mg/m2) was administered on day 1 every 3 weeks. Among 32 patients enrolled, 8 (25%) responded partially to paclitaxel/cisplatin, 8 (25%) had stable disease, and 14 (44%) had progressive disease. Two patients (6%) were not evaluable. The median time to progression (TTP) and overall survival for all patients were 2.9 months and 9.1 months, respectively. The most common hematologic toxicity was anemia (47%). Grade 3 neutropenia developed in three patients (9%), but no other grade 3/4 hematologic toxicity occurred. The most common non-hematologic toxicities were emesis (31%) and peripheral neuropathy (38%). Three cases (9%) of grade 3/4 emesis and 2 cases (6%) of grade 3 peripheral neuropathy developed. In conclusion, low-dose paclitaxel and cisplatin chemotherapy showed moderate activity with favorable toxicity profiles. However, relatively short TTP of this regimen warrants the development of more effective paclitaxel-based regimens other than combination with cisplatin in these patients as second-line therapies

Effect of Transcranial Direct Current Stimulation on Motor Recovery in Patients with Subacute Stroke

Kim DY, Lim JY, Kang EK, You DS, Oh MK, Oh BM, Paik NJ: Effect of transcranial direct current stimulation on motor recovery in patients with subacute stroke. Am J Phys Med Rehabil 2010;89:879-886. Objective: To test the hypothesis that 10 sessions of transcranial direct current stimulation combined with occupational therapy elicit more improvement in motor function of the paretic upper limb than sham stimulation in patients with subacute stroke. Design: Eighteen patients with subacute stroke with hand motor impairment were randomly assigned to one of the three 10-day sessions of (a) anodal transcranial direct current stimulation over the affected motor cortex, (b) cathodal transcranial direct current stimulation over the unaffected motor cortex, or (c) sham stimulation. Blinded evaluators assessed upper limb motor impairment and global functional state with the Fugl-Meyer Assessment score and the Modified Barthel Index at baseline, 1 day after stimulation, and 6 mos after stimulation. Results: Baseline scores for Fugl-Meyer Assessment and Modified Barthel Index were comparable in all groups (P > 0.05). At 6-mo follow-up, cathodal transcranial direct current stimulation led to a greater improvement in Fugl-Meyer Assessment than the sham procedure (P < 0.05). There was a significant inverse correlation between baseline Fugl-Meyer Assessment and Fugl-Meyer Assessment increase at 6 mos (r = -0.846; P < 0.01). Conclusions: Our results suggest a potentially beneficial effect of noninvasive cortical stimulation during rehabilitative motor training of patients who have suffered from subacute strokes.Fritsch B, 2010, NEURON, V66, P198, DOI 10.1016/j.neuron.2010.03.035Williams JA, 2009, J REHABIL MED, V41, P305, DOI 10.2340/16501977-0356Reis J, 2009, P NATL ACAD SCI USA, V106, P1590, DOI 10.1073/pnas.0805413106Schlaug G, 2008, ARCH NEUROL-CHICAGO, V65, P1571Vines BW, 2008, BMC NEUROSCI, V9, DOI 10.1186/1471-2202-9-103Mally J, 2008, BRAIN RES BULL, V76, P388, DOI 10.1016/j.brainresbull.2007.11.019Boggio PS, 2007, RESTOR NEUROL NEUROS, V25, P123Liepert J, 2007, RESTOR NEUROL NEUROS, V25, P461Boggio PS, 2006, AM J PHYS MED REHAB, V85, P927, DOI 10.1097/01.phm.0000242635.88129.38Uswatte G, 2006, NEUROLOGY, V67, P1189Hummel FC, 2006, LANCET NEUROL, V5, P708Gandiga PC, 2006, CLIN NEUROPHYSIOL, V117, P845, DOI 10.1016/j.clinph.2005.12.003Salter K, 2006, J REHABIL MED, V38, P113, DOI 10.1080/16501970500314350Wassermann EM, 2005, TRENDS COGN SCI, V9, P503, DOI 10.1016/i.tics.2005.09.001Nitsche MA, 2005, J PHYSIOL-LONDON, V568, P291, DOI 10.1113/jphysiol.2005.092429Fregni F, 2005, NEUROREPORT, V16, P1551Khedr EM, 2005, NEUROLOGY, V65, P466Hummel F, 2005, BRAIN, V128, P490, DOI 10.1093/brain/awh369Ward NS, 2004, ARCH NEUROL-CHICAGO, V61, P1844Murase N, 2004, ANN NEUROL, V55, P400, DOI 10.1002/ana.10848Kwakkel G, 2003, STROKE, V34, P2181, DOI 10.1161/01.STR.0000087172.16305.CDRathore SS, 2002, STROKE, V33, P2718Liebetanz D, 2002, BRAIN, V125, P2238Wolf SL, 2001, STROKE, V32, P1635Nitsche MA, 2000, J PHYSIOL-LONDON, V527, P633Cifu DX, 1999, ARCH PHYS MED REHAB, V80, pS35DUNCAN PW, 1994, STROKE, V25, P1181SHAH S, 1989, J CLIN EPIDEMIOL, V42, P703FUGLMEYER AR, 1975, SCAND J REHABIL MED, V7, P13