77 research outputs found

    Neutral and Cationic Rare Earth Metal Alkyl and Benzyl Compounds with the 1,4,6-Trimethyl-6-pyrrolidin-1-yl-1,4-diazepane Ligand and Their Performance in the Catalytic Hydroamination/Cyclization of Aminoalkenes

    Get PDF
    A new neutral tridentate 1,4,6-trimethyl-6-pyrrolidin-1-yl-1,4-diazepane (L) was prepared. Reacting L with trialkyls M(CH2SiMe3)3(THF)2 (M = Sc, Y) and tribenzyls M(CH2Ph)3(THF)3 (M = Sc, La) yielded trialkyl complexes (L)M(CH2SiMe3)3 (M = Sc, 1; M = Y, 2) and tribenzyl complexes (L)M(CH2Ph)3 (M = Sc, 3; M = La, 4). Complexes 1 and 2 can be converted to their corresponding ionic compounds [(L)M(CH2SiMe3)2(THF)][B(C6H5)4] (M = Sc, Y) by reaction with [PhNMe2H][B(C6H5)4] in THF. Complexes 3 and 4 can be converted to cationic species [(L)M(CH2Ph)2]+ by reaction with [PhNMe2H][B(C6F5)4] in C6D5Br in the absence of THF. The neutral complexes 1-4 and their cationic derivatives were studied as catalysts for the hydroamination/cyclization of 2,2-diphenylpent-4-en-1-amine and N-methylpent-4-en-1-amine reference substrates and compared with ligand-free Sc, Y, and La neutral and cationic catalysts. The most effective catalysts in the series were the cationic L-yttrium catalyst (for 2,2-diphenylpent-4-en-1-amine) and the cationic lanthanum systems (for N-methylpent-4-en-1-amine). For the La catalysts, evidence was obtained for release of L from the metal during catalysis.

    Porcine Islet-Specific Tolerance Induced by the Combination of Anti-LFA-1 and Anti-CD154 mAbs is Dependent on PD-1

    Get PDF
    [EN]We previously demonstrated that short-term administration of a combination of anti-LFA-1 and anti-CD154 monoclonal antibodies (mAbs) induces tolerance to neonatal porcine islet (NPI) xenografts that is mediated by regulatory T cells (Tregs) in B6 mice. In this study, we examined whether the coinhibitory molecule PD-1 is required for the induction and maintenance of tolerance to NPI xenografts. We also determined whether tolerance to NPI xenografts could be extended to allogeneic mouse or xenogeneic rat islet grafts since we previously demonstrated that tolerance to NPI xenografts could be extended to second-party NPI xenografts. Finally, we determined whether tolerance to NPI xenografts could be extended to allogeneic mouse or second-party porcine skin grafts. Diabetic B6 mice were transplanted with 2,000 NPIs under the kidney capsule and treated with short-term administration of a combination of anti-LFA-1 and anti-CD154 mAbs. Some of these mice were also treated simultaneously with anti-PD-1 mAb at >150 days posttransplantation. Spleen cells from some of the tolerant B6 mice were used for proliferation assays or were injected into B6 rag−/− mice with established islet grafts from allogeneic or xenogeneic donors. All B6 mice treated with anti-LFA-1 and anti-CD154 mAbs achieved and maintained normoglycemia until the end of the study; however, some mice that were treated with anti-PD-1 mAb became diabetic. All B6 rag−/− mouse recipients of first- and second-party NPIs maintained normoglycemia after reconstitution with spleen cells from tolerant B6 mice, while all B6 rag−/− mouse recipients of allogeneic mouse or xenogeneic rat islets rejected their grafts after cell reconstitution. Tolerant B6 mice rejected their allogeneic mouse or xenogeneic second-party porcine skin grafts while remaining normoglycemic until the end of the study. These results show that porcine islet-specific tolerance is dependent on PD-1, which could not be extended to skin grafts.SIWe acknowledge the technical assistance of Deb Dixon and Dawne Colwell and thoughtful discussions with Dr. Tsunehiro Kobayashi. We are grateful to the Canadian Diabetes Association, which provided major funding for this work as well as the Edmonton Civic Employees’ Charitable Assistance Fund, Stollery Children’s Hospital Foundation, the MacLachlan Fund University Hospital Foundation, Canadian Institutes of Health Research, Colliers International, Ken and Denise Cantor as well as Ewa and John Burton, who provided additional support. The Muttart Diabetes Research Training Centre provided scholarship for H.A. The authors declare no conflicts of interest

    Analysis of Allogenicity of Mesenchymal Stem Cells in Engraftment and Wound Healing in Mice

    Get PDF
    Studies have shown that allogeneic (allo-) bone marrow derived mesenchymal stem cells (BM-MSCs) may enhance tissue repair/regeneration. However, recent studies suggest that immune rejection may occur to allo-MSCs leading to reduced engraftment. In this study, we compared allo-BM-MSCs with syngeneic BM-MSCs or allo-fibroblasts in engraftment and effect in wound healing. Equal numbers of GFP-expressing allo-BM-MSCs, syngeneic BM-MSCs or allo-fibroblasts were implanted into excisional wounds in GFP-negative mice. Quantification of GFP-expressing cells in wounds at 7, 14 and 28 days indicated similar amounts of allogeneic or syngeneic BM-MSCs but significantly reduced amounts of allo-fibroblasts. With healing progression, decreasing amounts of allogeneic and syngeneic BM-MSCs were found in the wound; however, the reduction was more evident (2 fold) in allo-fibroblasts. Similar effects in enhancing wound closure were found in allogeneic and syngeneic BM-MSCs but not in allo-fibroblasts. Histological analysis showed that allo-fibroblasts were largely confined to the injection sites while allo-BM-MSCs had migrated into the entire wound. Quantification of inflammatory cells in wounds showed that allo-fibroblast- but not allo-BM-MSC-treated wounds had significantly increased CD45+ leukocytes, CD3+ lymphocytes and CD8+ T cells. Our study suggests that allogeneic BM-MSCs exhibit ignorable immunogenicity and are equally efficient as syngeneic BM-MSCs in engraftment and in enhancing wound healing

    Phenotypic differences between dermal fibroblasts from different body sites determine their responses to tension and TGFβ1

    Get PDF
    BACKGROUND: Wounds in the nonglabrous skin of keloid-prone individuals tend to cause large disordered accumulations of collagen which extend beyond the original margins of the wound. In addition to abnormalities in keloid fibroblasts, comparison of dermal fibroblasts derived from nonwounded glabrous or nonglabrous skin revealed differences that may account for the observed location of keloids. METHODS: Fibroblast apoptosis and the cellular content of α-smooth-muscle actin, TGFβ1 receptorII and ED-A fibronectin were estimated by FACS analysis. The effects of TGFβ1 and serum were examined. RESULTS: In monolayer cultures non-glabrous fibroblasts were slower growing, had higher granularity and accumulated more α-smooth-muscle actin than fibroblasts from glabrous tissues. Keloid fibroblasts had the highest level of α-smooth-muscle actin in parallel with their expression level of ED-A fibronectin. TGFβ1 positively regulated α-smooth-muscle actin expression in all fibroblast cultures, although its effects on apoptosis in fibroblasts from glabrous and non-glabrous tissues were found to differ. The presence of collagen I in the ECM resulted in reduction of α-smooth-muscle actin. A considerable percentage of the apoptotic fibroblasts in attached gels were α-smooth-muscle actin positive. The extent of apoptosis correlated positively with increased cell and matrix relaxation. TGFβ1 was unable to overcome this apoptotic effect of matrix relaxation. CONCLUSION: The presence of myofibroblasts and the apoptosis level can be regulated by both TGFβ1 and by the extracellular matrix. However, reduction of tension in the matrix is the critical determinant. This predicts that the tension in the wound bed determines the type of scar at different body sites

    Add-on topiramate reduces weight in overweight patients with affective disorders: a clinical case series

    Get PDF
    BACKGROUND: The weight-gain caused by many psychotropic drugs is a major cause for poor compliance with such medications and could also increase cardio-vascular morbidity among psychiatric patients. Recent reports have shown that the anticonvulsant topiramate causes weight loss in various patient groups. The drug has also shown effectiveness in open trials as a mood stabilizer in patients with affective disorders, but not in controlled trials in the acute treatment of mania. We used topiramate to treat 12 patients with affective disorders who had a body-mass index >30 kg/m(2). METHODS: Topiramate was prescribed as part of our routine clinical practice, as an add-on medication, or as a replacement of a mood stabilizer. Patients' weight was recorded in 1 to 2 monthly intervals. Patients were followed up for between 6 and 12 months. The final dose of topiramate varied from 200 to 600 mg/day. RESULTS: Topiramate was effective in reducing the weight in 10 out of the 12 patients. At six months the 12 patients had lost a mean of 7.75 kg (SD = 6.9 kg, p < 0.001) and at 12 months 9 patients had lost a mean of 9.61 kg (SD = 6.7 kg, p = 0.003). Three patients stopped the treatment: one due to side effects, one due to possible side effects, and one suffered a manic relapse and showed no sustained weight loss. There were no other clear changes in the course of illness of the patients. CONCLUSION: The evidence of a strong weight-reducing potential of topiramate is indisputable and clinically significant. Topiramate could be considered in the treatment of bipolar patients who are overweight, or whose concerns about weight gain compromise their compliance with long-term prophylactic medication. So far there is no evidence that topiramate has anti-manic effect and it should not be used as monotherapy

    Focus on collagen: in vitro systems to study fibrogenesis and antifibrosis _ state of the art

    Get PDF
    Fibrosis represents a major global disease burden, yet a potent antifibrotic compound is still not in sight. Part of the explanation for this situation is the difficulties that both academic laboratories and research and development departments in the pharmaceutical industry have been facing in re-enacting the fibrotic process in vitro for screening procedures prior to animal testing. Effective in vitro characterization of antifibrotic compounds has been hampered by cell culture settings that are lacking crucial cofactors or are not holistic representations of the biosynthetic and depositional pathway leading to the formation of an insoluble pericellular collagen matrix. In order to appreciate the task which in vitro screening of antifibrotics is up against, we will first review the fibrotic process by categorizing it into events that are upstream of collagen biosynthesis and the actual biosynthetic and depositional cascade of collagen I. We point out oversights such as the omission of vitamin C, a vital cofactor for the production of stable procollagen molecules, as well as the little known in vitro tardy procollagen processing by collagen C-proteinase/BMP-1, another reason for minimal collagen deposition in cell culture. We review current methods of cell culture and collagen quantitation vis-à-vis the high content options and requirements for normalization against cell number for meaningful data retrieval. Only when collagen has formed a fibrillar matrix that becomes cross-linked, invested with ligands, and can be remodelled and resorbed, the complete picture of fibrogenesis can be reflected in vitro. We show here how this can be achieved. A well thought-out in vitro fibrogenesis system represents the missing link between brute force chemical library screens and rational animal experimentation, thus providing both cost-effectiveness and streamlined procedures towards the development of better antifibrotic drugs

    Plasma and neutrophil fatty acid composition in advanced cancer patients and response to fish oil supplementation

    Get PDF
    Metabolic demand and altered supply of essential nutrients is poorly characterised in patients with advanced cancer. A possible imbalance or deficiency of essential fatty acids is suggested by reported beneficial effects of fish oil supplementation. To assess fatty acid status (composition of plasma and neutrophil phospholipids) in advanced cancer patients before and after 14 days of supplementation (12±1 g day−1) with fish (eicosapentaenoic acid, and docosahexaenoic acid) or placebo (olive) oil. Blood was drawn from cancer patients experiencing weight loss of >5% body weight (n=23). Fatty acid composition of plasma phospholipids and the major phospholipid classes of isolated neutrophils were determined using gas liquid chromatography. At baseline, patients with advanced cancer exhibited low levels (<30% of normal values) of plasma phospholipids and constituent fatty acids and elevated 20 : 4 n-6 content in neutrophil phospholipids. High n-6/n-3 fatty acid ratios in neutrophil and plasma phospholipids were inversely related to body mass index. Fish oil supplementation raised eicosapentaenoic acid and docosahexaenoic acid content in plasma but not neutrophil phospholipids. 20 : 4 n-6 content was reduced in neutrophil PI following supplementation with fish oil. Change in body weight during the supplementation period related directly to increases in eicosapentaenoic acid in plasma. Advanced cancer patients have alterations in lipid metabolism potentially due to nutritional status and/or chemotherapy. Potential obstacles in fatty acid utilisation must be addressed in future trials aiming to improve outcomes using nutritional intervention with fish oils

    Functional Genomics Unique to Week 20 Post Wounding in the Deep Cone/Fat Dome of the Duroc/Yorkshire Porcine Model of Fibroproliferative Scarring

    Get PDF
    Background: Hypertrophic scar was first described over 100 years ago; PubMed has more than 1,000 references on the topic. Nevertheless prevention and treatment remains poor, because 1) there has been no validated animal model; 2) human scar tissue, which is impossible to obtain in a controlled manner, has been the only source for study; 3) tissues typically have been homogenized, mixing cell populations; and 4) gene-by-gene studies are incomplete.Methodology/Principal Findings: We have assembled a system that overcomes these barriers and permits the study of genome-wide gene expression in microanatomical locations, in shallow and deep partial-thickness wounds, and pigmented and non-pigmented skin, using the Duroc( pigmented fibroproliferative)/Yorkshire( non-pigmented non-fibroproliferative) porcine model. We used this system to obtain the differential transcriptome at 1, 2, 3, 12 and 20 weeks post wounding. It is not clear when fibroproliferation begins, but it is fully developed in humans and the Duroc breed at 20 weeks. Therefore we obtained the derivative functional genomics unique to 20 weeks post wounding. We also obtained long-term, forty-six week follow-up with the model.Conclusions/Significance: 1) the scars are still thick at forty-six weeks post wounding further validating the model. 2) the differential transcriptome provides new insights into the fibroproliferative process as several genes thought fundamental to fibroproliferation are absent and others differentially expressed are newly implicated. 3) the findings in the derivative functional genomics support old concepts, which further validates the model, and suggests new avenues for reductionist exploration. in the future, these findings will be searched for directed networks likely involved in cutaneous fibroproliferation. These clues may lead to a better understanding of the systems biology of cutaneous fibroproliferation, and ultimately prevention and treatment of hypertrophic scarring.The National Institute on Disability and Rehabilitation ResearchThe National Institutes of HealthThe Washington State Council of Fire Fighters Burn FoundationThe Northwest Burn FoundationUniv Washington, Dept Surg, Div Plast Surg, Seattle, WA 98195 USAIowa State Univ, Dept Anim Sci, Ames, IA USAUniv Washington, Dept Biostat, Seattle, WA 98195 USAMahidol Univ, Ramathibodi Hosp, Dept Surg, Bangkok 10700, ThailandUniv Washington, Dept Environm & Occupat Hlth Sci, Seattle, WA 98195 USAUniversidade Federal de São Paulo, Div Plast Surg, Dept Surg, São Paulo, BrazilUniversidade Federal de São Paulo, Div Plast Surg, Dept Surg, São Paulo, BrazilThe National Institute on Disability and Rehabilitation Research: H133G050022The National Institutes of Health: 1R21GM074673The National Institutes of Health: 5U54GM062119-09Web of Scienc
    corecore